description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
This invention generally pertains to machines for chopping or comminuting lumps carried with a liquid into pieces of acceptably smaller size which can be subsequently removed from the liquid or disposed of along with the liquid. More particularly, this invention pertains to a rotatable chopper adapted for mounting directly in the line of a process pipe or conduit to chop all lumps passing through the pipe into acceptable size.
The nearest presently known prior art appears in U.S. Pat. No. 2,273,405 which shows a rotary type of disintegrating mill suitable to make a puree of foodstuffs and the like and in U.S. Pat. No. 3,439,361 which shows a rotary type sewage comminuting apparatus.
SUMMARY OF THE INVENTION
The present invention provides a rotary chopper which may be installed as a permanent component of a process pipe or line and be completely repairable or rebuildable without disturbing the process line piping which may be flanged, welded or the like.
The present invention also provides apparatus having a plurality of interchangeable rotatable and stationary operating components which may be fabricated simply and in quantity as spare and replacement parts.
The present invention provides a chopping apparatus adapted to chop lumps flowing into the apparatus with substantially constant torque requirements throughout complete rotation of the chopping elements.
Other provisions and advantages of the invention will become more apparent in the detailed description of a rotatable chopping machine including a hollow body defining two conduit ends adapted for fixed connection into a flow line and defining a cylindrical bore fully intersecting the flow path between the conduit ends. The cylindrical bore has closure caps at both its ends with at least one of said caps being a removable cap to the full diameter of the bore and a rotatable shaft extending axially through the bore, through one of said closure caps and adapted for rotation by an external power source. A plurality of elongated rotatable cutter blades are transversely fastened in splined relation to the shaft to rotate with the shaft with each rotatable blade being angularly displaced on said shaft with respect to each adjacent rotatable blade and with each said rotatable blade extending near to the wall of the bore. A plurality of elongated stationary cutter blades are mounted in journaled relation on the shaft with each said stationary cutter blade being disposed adjacent a rotatable cutter blade and extending to the wall of said bore with the total combination of the rotatable blades and the stationary blades being adapted to effectively intersect the complete flow path between the conduit ends. A retainer means within said bore is adapted to retain said stationary cutter blades against rotation. The assembly of the removable cap, the shaft, the rotatable cutter blades and the stationary pg,4 cutter blades are all removable from the body and replaceable in said body with individual parts being repaired or replaced as necessary.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partly plan partly sectional view taken along the axes of the flow conduit bores and the intersecting bore which houses the shaft and chopper blades as later described;
FIG. 2 is a partly sectional elevational view taken along the line 2--2 shown in FIG. 1 and showing the angular relationship of the cutter blades;
FIG. 3 is a partial sectional view taken along the line 3--3 as shown in FIGS. 1 and 2;
FIG. 4 is a perspective view of a stationary cutter blade of the apparatus; and
FIG. 5 is a perspective view of a rotatable cutter blade of the present apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present embodiment is typified as being utilized in the reaction product discharge pipe of a polyvinyl chloride reactor where the discharged reaction product includes lumps which are reduced in size to properly pass through valves, pumps, separators and the like.
Referring to FIG. 1, the rotary cutter or chopper 10 of the present invention is shown with its generally hollow housing or body 12 connected into a process pipe line through process pipe flanges 14 and 16. Body 12 defines flow conduits 18 and 20 terminating in flanges 22 and 24 which are connected to pipe flanges 14 and 16 by means of gaskets and suitable fasteners (not shown) such as studs and nuts for example. The conduits 18 and 20 may also be connected into the process line pipe with welded or threaded connections as desired.
The body 12 defines a cylindrical bore 26 which intersects the fluid flow path between conduits 18 and 20.
The four support lugs 28 as shown on the body 12 may be provided to mount the body 12 to a suitable support base or bracket (not shown) which may also be used to mount the power unit (not shown) utilized to drive the chopper 10.
The body 12 is provided with flanges 30 and 32 at the ends of bore 26 to which are attached in sealed relation covers or caps 34 and 36 by means of fasteners 38 such as bolts. Caps 34 and 36 could also be attached by threaded connection under some conditions. Also, as will become evident, only one of caps 34 or 36 is required to be removable although providing both caps as being removable is more convenient for the embodiment shown.
A rotatable shaft 40 extends axially through the cylindrical bore 26 and through one of the caps such as cap 36 as shown. Shaft 40 is journaled in centered relation within bearings 42 and 44 mounted respectively in each cap as shown. A fluid packing or stuffing assembly 46 is provided on the cap through which shaft 40 extends, such as on cap 36 in FIG. 1, to prevent escape of liquids from within body 12 about the shaft. As shown a cap 48 having a threaded hole for a plug (not shown) is attached to cap 34 outside bearing 42 as a convenience in manufacture and maintenance.
In comparing FIGS. 1-3, it is seen that shaft 40 is round at its ends where it is journaled in bearings 42 and 44 and through packing 46 but is polygonal through its length between the bearings 42 and 44, depicted in FIGS. 2 and 3 as being hexagonal in shape at portion 50.
As shown in FIG. 3, stationary cutter blades 52 (FIG. 4) and rotatable cutter blades 54 (FIG. 5) are alternately mounted along the hexagon portion 50 of shaft 40 and adjacently spaced apart with spacer bearings 56. As shown in FIGS. 3 and 4 the stationary cutter blade is provided with a round center hole which receives a journal bearing 58 which fits about hexagon portion 50 and allows the shaft 40 to rotate within the stationary blade 52. As shown in FIGS. 3 and 5, the rotatable cutter blade 54 is provided with a center hole of shape which registers in splined relation on hexagon portion 50 of shaft 40 and is adapted to be driven in rotation by the shaft 40.
The center edges of stationary blades 52 may be sharpened as at 60 to facilitate passage of lumps between the stationary blades. The ends of stationary blades may also be provided with axially extended flanges 62 into which the rotatable blades nest into as shown in FIGS. 2 and 3. With the nesting arrangement as shown in FIG. 3 the largest piece of a lump which can pass through the chopper will be no larger than the passage areas such as defined at 63.
The leaing edges of rotatable blades 54 are defined somewhat of scythe shape as at 66 on FIG. 5 to help catch and engage lumps passing through the cutter 10 for chopping into sizes passable through passage areas 63.
As seen in FIGS. 1, 2 and 3, the adjacent rotatable cutter blades 54 are mounted in angularly displaced relation on hexagonal section 50 of shaft with each blade 54 being at 60°, for example, relative to the next blade 54. Such angular displacement is helpful to distribute the fluid flow through the cylindrical bore 26, to distribute the lumps to be chopped and to stabilize the resulting torque required to rotate shaft 40.
Stationary cutter blades 52 are shown in FIGS. 2 and 3 to be restrained in stationary non-rotating position within body 12 by a pair of retainer guide lugs 64 which are mounted in parallel relation along the wall of cylindrical bore 26 and parallel with the axis of the bore. Other retaining means may be provided but the retainer lugs 64 and 66 as shown are convenient to fabricate and facilitate installation and removal of the assembly of the shaft 40, cap 36, and cutter blades 52 and 54 as is evident. It is to be noted that the stationary blades 52 extend close to the wall of bore 26 and the rotatable blades 54 extend close to the internal walls of flanges 62 of the blades 52. Thus all particles must pass through an area not larger than a passage area 63.
As a matter of perspective, the rotary cutter 10 was first manufactured and installed in the reaction product discharge line pipe of a polyvinyl chloride reactor. The discharged reaction product contains lumps of sizes too large to properly pass through valves, pumps, separators and the like. The rotary cutter 10 serves to reduce such lumps into sizes which can be further processed conveniently.
As an example, the rotary cutter 10 may have flow conduits 18 and 20 of about 4 inches (10.16 cm) pipe size and a bore 26 of about 6 inches (15.24 cm) pipe size. Such a cutter 10 can utilize about 5-10 Hp (3.73-7.46 Kw) at 75-100 R.P.M., depending on the character and quantity of fluid passing through the cutter or chopper 10.
The foregoing description and drawing will suggest other embodiments and variations to those skilled in the art, all of which are intended to be included in the spirit of the invention as hereinafter set forth. | A rotatable machine for chopping or comminuting lumps, curds or chunks of material into particles or pieces of acceptably smaller size adapted for permanent installation in a liquid flow line. Includes an internal chopping combination of rotatable and stationary blades intersecting the flow path of the flow line and adapted to be removed, repaired or completely rebuilt, and replaced without the consequent time, labor and expense of removing the main body from the flow line. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to methods for conditioning fuel cells such that they are capable of performing normally after initial manufacture or after prolonged storage. In particular, it relates to methods for conditioning solid polymer fuel cells.
2. Description of the Related Art
Fuel cell systems are increasingly being used as power supplies in various applications, such as stationary power plants and portable power units. Such systems offer promise of economically delivering power while providing environmental benefits.
Fuel cells convert fuel and oxidant reactants to generate electric power and reaction products. They generally employ an electrolyte disposed between cathode and anode electrodes. A catalyst typically induces the desired electrochemical reactions at the electrodes. Preferred fuel cell types include solid polymer electrolyte (SPE) fuel cells that comprise a solid polymer electrolyte and operate at relatively low temperatures. Another fuel cell type that operates at a relatively low temperature is the phosphoric acid fuel cell.
SPE fuel cells employ a membrane electrode assembly (MEA) that comprises the solid polymer electrolyte or ion-exchange membrane disposed between the cathode and anode. (Typically, the electrolyte is bonded under heat and pressure to the electrodes and thus such an MEA is dry as assembled.) Each electrode contains a catalyst layer, comprising an appropriate catalyst, located next to the solid polymer electrolyte. The catalyst is typically a precious metal composition (e.g., platinum metal black or an alloy thereof) and may be provided on a suitable support (e.g., fine platinum particles supported on a carbon black support). The catalyst layers may contain ionomer similar to that used for the solid polymer membrane electrolyte (e.g., Nafion®). The electrodes may also contain a porous, electrically conductive substrate that may be employed for purposes of mechanical support, electrical conduction, and/or reactant distribution, thus serving as a fluid diffusion layer. Flow field plates for directing the reactants across one surface of each electrode or electrode substrate, are disposed on each side of the MEA. In operation, the output voltage of an individual fuel cell under load is generally below one volt. Therefore, in order to provide greater output voltage, numerous cells are usually stacked together and are connected in series to create a higher voltage fuel cell stack.
During normal operation of a SPE fuel cell, fuel is electrochemically oxidized at the anode catalyst, typically resulting in the generation of protons, electrons, and possibly other species depending on the fuel employed. The protons are conducted from the reaction sites at which they are generated, through the electrolyte, to electrochemically react with the oxidant at the cathode catalyst. The electrons travel through an external circuit providing useable power and then react with the protons and oxidant at the cathode catalyst to generate water reaction product.
A broad range of reactants can be used in SPE fuel cells and may be supplied in either gaseous or liquid form. For example, the oxidant stream may be substantially pure oxygen gas or a dilute oxygen stream such as air. The fuel may be, for example, substantially pure hydrogen gas, a gaseous hydrogen-containing reformate stream, or an aqueous liquid methanol mixture in a direct methanol fuel cell.
During manufacture of SPE fuel cells, it is common to employ a conditioning or activating step in order to hydrate the membrane and also any ionomer present in the catalyst layers (e.g., as disclosed in Canadian patent application serial number 2,341,140). However, the fuel cells may also be “run in”. For instance, they may be operated for a period of time under controlled load conditions in a manner akin to a breaking in period, after which the nominal rated performance of the fuel cell is obtained. Such a breaking in process however may be onerous in large-scale manufacture since connecting up and operating each stack represents a relatively complex, time-consuming, and expensive procedure.
For various reasons, fuel cell performance can fade with operation time or as a result of storage. However, some of these performance losses may be reversible. For instance, the negative effect of the membrane electrolyte and/or other ionomer drying out during storage can be reversed by rehydrating the fuel cell. Also, the negative effects of CO contamination of an anode catalyst can be reversed using electrical and/or fuel starvation techniques. Published PCT patent applications WO99/34465, WO01/01508, and WO01/03215 disclose some of the other various advantages and/or performance improvements that can be obtained using appropriate starvation techniques in fuel cells.
While some of the mechanisms affecting performance in fuel cells are understood and means have been developed to mitigate them, other mechanisms affecting performance are not yet fully understood and unexpected effects on performance are just being discovered.
BRIEF SUMMARY OF THE INVENTION
In certain circumstances, a fuel cell may be performing below normal, but with prolonged operation, fuel cell performance may slowly rise to normal. In such circumstances, it has been discovered that performance can be timely improved by appropriately exposing the cathode to a reductant. For instance, this method may be used to activate a fuel cell after initial manufacture, thereby obviating a lengthy activation process. Alternatively, this method may be used to rejuvenate a fuel cell following prolonged storage.
The conditioning method is used prior to normal operation. Herein, normal operation is defined as supplying a fuel stream to the anode of the fuel cell, supplying an oxidant stream to the cathode of the fuel cell, and supplying power from the fuel cell to an external electrical load. The conditioning method then comprises directing a fluid comprising a reductant to the cathode without supplying oxidant to the cathode. Further, the fluid comprising the reductant may be directed to the cathode without supplying power from the fuel cell to the external electrical load. Thus, while shorting and/or starvation techniques may also be employed, they are not required using the present method. A preferred reductant is hydrogen although other reductants (e.g., hydrogen peroxide) may be used instead.
The method is suitable for use with fuel cells whose cathode comprises a precious metal catalyst (e.g., platinum) and is particularly suitable for use with typical solid polymer electrolyte fuel cells. In the method, the reductant may desirably be heated and humidified before directing to the cathode. The reductant fluid is typically directed to a cathode flowfield in the fuel cell.
The method is particularly advantageous for manufacturing purposes and for commercial applications where the fuel cell stack spends prolonged periods inactive and yet desirably delivers normal output power in a timely manner once put into service. In this regard, it may be desirable that the commercial fuel cell system is capable of automatically conditioning itself (i.e., self-conditioning).
A possible embodiment of a self-conditioning system comprises a fuel cell, a fuel supply system, an oxidant supply system, and a controller. In this embodiment, the fuel cell comprises an anode, a cathode, and an electrolyte. The fuel supply system comprises a fuel supply, fuel supply lines fluidly connecting the fuel supply to the anode and the cathode, and fuel valving for controlling the flow of fuel to the anode and to the cathode. The oxidant supply system comprises an oxidant supply, an oxidant supply line fluidly connecting the oxidant supply to the cathode, and oxidant valving for controlling the flow of oxidant to the cathode. Finally, the controller is used to control the fuel and oxidant valving such that fuel is supplied to the anode and that oxidant is supplied to the cathode during normal operation, but such that fuel is supplied to the cathode and that oxidant is not supplied to the cathode during conditioning.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of a solid polymer fuel cell system equipped to condition the fuel cell by directly supplying hydrogen gas to the cathode.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic diagram of a solid polymer fuel cell system in which the fuel cell may be self-conditioned in accordance with the invention. Conditioning may be performed either to rejuvenate the fuel cell after undergoing a temporary performance loss as a result of prolonged storage or to activate the fuel cell such that it is capable of nominal performance immediately after initial manufacture.
For simplicity, FIG. 1 shows only one cell in the fuel cell stack in system 1 . Fuel cell stack 2 comprises a membrane electrode assembly consisting of solid polymer electrolyte membrane 3 sandwiched between cathode 4 and anode 5 . (Both cathode 4 and anode 5 comprise porous substrates and catalyst layers which are not shown.) Stack 2 also comprises cathode flow field plate 6 and anode flow field plate 7 for distributing reactants to cathode 4 and anode 5 respectively. System 1 also has fuel and oxidant supply systems containing oxidant supply 8 (typically air, which may be supplied by a blower or compressor) and fuel supply 9 (considered here to be a source of hydrogen gas).
During normal operation, oxidant and fuel streams are supplied to flow field plates 6 and 7 respectively via oxidant and fuel supply lines 10 and 11 respectively. The oxidant and fuel streams exhaust from stack 2 via exhaust lines 12 and 13 respectively. Power from stack 2 is delivered to external electrical load 14 , which is electrically connected across the terminals of stack 2 .
In FIG. 1 , system 1 is equipped to condition stack 2 by directly supplying cathode 4 with hydrogen gas. System 1 includes oxidant shutoff valve 15 , fuel shutoff valve 16 , fuel conditioning valve 17 , and controller 18 . The operation of the valves is controlled by controller 18 via the various dashed signal lines depicted in FIG. 1 . During normal operation, oxidant shutoff valve 15 and fuel shutoff valve 16 are open, while fuel conditioning valve 17 is closed. Thus, oxidant and fuel (hydrogen here) are supplied normally to cathode 4 and anode 5 respectively. When the system is inactive (e.g., during storage), valves 15 , 16 , and 17 are all closed and there is no flow of reactant to or from stack 2 . (Not shown in FIG. 1 are shutoff valves in exhaust lines 12 and 13 , which may also be provided to prevent contaminants from entering stack 2 .) For conditioning however, controller 18 signals oxidant shutoff valve 15 to close and signals fuel shutoff valve 16 and fuel conditioning valve 17 to open thereby providing hydrogen directly to cathode 4 . A flow of hydrogen to anode 5 is optional when conditioning using the system of FIG. 1 . Thus, flow through anode flow field plate 7 may be prevented by use of an additional shutoff valve in fuel exhaust line 13 if desired (not shown). In general, the presence of external electrical load 14 during conditioning is also optional. However, depending on the specific embodiment, it may be desirable to disconnect load 14 (e.g., to protect it from power surges) or to keep it connected instead (to additionally implement a starvation condition).
Stack 2 is rejuvenated by exposing cathode 6 to hydrogen. Preferably the hydrogen is heated and humidified in order to accelerate the rejuvenation process. Means for heating and humidifying may thus desirably be included as part of hydrogen supply 9 .
System 1 is thus equipped to condition itself as is required in the field. Controller 18 may be programmed for instance to run the system through a conditioning cycle every time it is started up to ensure that the fuel cell is operating normally. In such a case, the starting sequence may then involve automatic configuring of valves 15 , 16 , and 17 so as to condition for a brief period (e.g., of order of a minute), followed by a configuring for normal operation.
The method of the invention can also be readily employed on conventional SPE fuel cell systems, in which case the operator arranges conditioning as desired. Again, hydrogen is directed to the cathode either manually or via a suitable external apparatus (e.g., a conditioning unit) that can be appropriately connected to the system. Thus, conventional fuel cells or systems can be activated in this way during manufacture at a conditioning station on an assembly line. Alternatively, conventional fuel cells or systems may be rejuvenated after prolonged storage in the field or at a service center using a suitable conditioning unit.
Using the aforementioned methods, SPE fuel cells that had been adversely affected by prolonged storage can be successfully rejuvenated relatively quickly. For instance, SPE fuel cell stacks operating at current densities about 400 mA/cm 2 may exhibit output voltage drops of order of 10-20 mV per cell after storing under ambient conditions for a month (the voltage drops being greater at higher ambient temperature conditions). When put back into normal service without any prior conditioning, such stacks can require over a day of operation before recovering completely. On the other hand, similar stacks show almost complete recovery immediately after a conditioning period of the order of a minute.
Without being bound by theory, it is believed that the lower than nominal performance capability seen in newly manufactured SPE fuel cells or in cells subjected to prolonged storage may be due to the formation of oxides or hydroxides on the surface of the cathode catalyst. Such species could be expected to form in the presence of oxygen and water and the rate would increase at elevated temperatures. Reducing the cathode catalyst then, such as with suitable exposure to hydrogen (or other reductant) or by operating the cell for a sufficiently long period, would then be expected to react these species away. The reduction reaction would thus form water and leave behind catalyst whose surface was free of oxide/hydroxide thereby activating or rejuvenating the catalyst and also, to some extent, rehydrating the fuel cell. (Noticing an adverse effect on performance with the formation of oxides and/or hydroxides on a platinum cathode catalyst surface would be consistent with the observations of M. Pourbaix “Atlas of Electrochemical Equilibria in Aqueous Solutions”, 1966, Pergamon Press, N.Y. and A. J. Appleby and A. Borucka, J. Electrochem. Soc. 116, 1212 (1969), who reported that oxygen reduction rates are higher for platinum than for platinum hydroxide or for oxidized platinum respectively.)
Accordingly, other methods to assist in the removal of surface oxides/hydroxides from the cathode catalyst or to prevent their formation are also desirably contemplated. For instance, oxidant starving techniques may be employed to assist in the removal. Also, for instance, the fuel cell might be maintained in a conditioned state in various ways in order to prevent temporary losses in performance capability. As an example, storing the fuel cell at below ambient temperature would slow the rate of formation of oxides or hydroxides. Blanketing the cathode with an inert gas such as dry nitrogen during storage would also be expected to slow the formation of oxide/hydroxide species. In this regard, a reducing atmosphere would be inert and maintaining a reducing atmosphere around the cathode (by directly admitting hydrogen or by allowing hydrogen from the anode to diffuse across the membrane electrolyte to the cathode) would be preferred.
If the fuel cell can be maintained in a suitably conditioned state, one may consider performing conditioning cycles well before the fuel cell actually needs to be used. For instance, in the embodiment of FIG. 1 , one may also consider running conditioning cycles partway through a storage period or even at shutdown.
The following examples are provided to illustrate certain aspects and embodiments of the invention but should not be construed as limiting in any way.
EXAMPLE 1
A solid polymer fuel cell stack comprising 24 cells stacked in series was assembled and fully conditioned by operating it under load until its full normal performance capability was reached. Each cell in the stack contained a 115 cm 2 active area membrane electrode assembly with platinum catalyzed electrodes and a NAFION® N112 perfluorosulfonic acid membrane electrolyte. On both cathode and anode, carbon-supported Pt catalyst was employed on carbon fiber substrates. The stack employed serpentine flow field plates made of graphite clamped between end plates at a loading of 1200 lbs. Typical normal operation for this stack involves supplying 100% RH hydrogen and air, at about 1 and 3 psi, respectively, to the cathode and anode flow field plates respectively. The normal operating temperature of the stack is 65° C. and the maximum normal operating current for this cell is about 50 A. Under this 50 A load, the average voltage of the cells in the fully conditioned stack is about 660 mV/cell.
In the last 10 cells in the stack, the membrane electrode assemblies (MEAs) were then replaced with similar newly assembled MEAs. The reconstructed stack was then operated without any prior conditioning under a load of 50 amps. The initial average voltage of the new cells was 540 mV whereas the initial voltage of the original cells was 640 mV. The stack was run for 30 minutes during which time the membrane electrolytes in the new and original cells became hydrated or rehydrated respectively. After this period, the average voltage of the new cells had increased to about 578 mV while that of the original cells remained at about 640 mV. Next, dry, unheated hydrogen was piped through both the stack anodes and cathodes for five minutes. Immediately thereafter, the average voltage of the new cells was about 32 mV higher while the average voltage of the original cells had increased by 20 mV. The brief exposure to dry, ambient temperature hydrogen appeared to accelerate the conditioning process, although the cells were still not completely conditioned yet.
The 10 new MEAs were then replaced again with similar newly assembled MEAs. This time, heated and humidified hydrogen (80° C. and 100% RH) was directed through both the stack anodes and cathodes for 5 minutes. The stack was then operated under load as before. This time, the average voltage of the new cells MEAs was 630 mV after starting while the average voltage of the original cells was 650 mV. After 10 hours of further operation under 50 A load, the average voltage of the original cells was 660 mV while that of the new cells was 650 mV.
Thus, the brief exposure to heated and humidified hydrogen brought the reconstructed stack almost to the nominal operating voltage (within 95% of normal).
EXAMPLE 2
Another similar solid polymer fuel cell stack comprising 47 cells stacked in series but slightly different flow plates was assembled and fully conditioned by operating it under load until its full normal performance capability was reached. Except for the number of cells, the construction of this stack was similar to that of the stack in Example 1. The normal operating conditions for this stack were also similar to that of Example 1 except that dry, unhumidified hydrogen was used as the fuel supply.
Under a 50 A load, the average voltage of the cells in this fully conditioned stack was about 620 mV/cell. The stack was then shutdown and stored for two months under ambient conditions. After the storage period, the stack was restarted without undergoing a conditioning procedure and was operated normally for an hour. The average voltage of the cells was 590 mV. Operation of the stack was then stopped and the stack was conditioned by flooding the cathode with partially humidified hydrogen gas for about five minutes. The stack was then started again and operated normally for an hour. This time, the average voltage of the cells was 610 mV immediately after starting and stabilized at the original 620 mV level after 10 hours of operation.
Thus, the brief exposure to partially humidified hydrogen brought the stored stack almost to the nominal operating voltage on startup.
EXAMPLE 3
Several solid polymer fuel cell stacks similar to those in Example 2 were assembled and fully conditioned by operating under load until full normal performance capability was reached. The stacks were then shut down by removing the load, reducing the fuel and oxidant reactant pressures, and closing the reactant inlets and outlets. The stacks were then stored at various different temperatures, namely −20° C., ambient (actually varying between 20 and 30° C.), and 70° C. The stacks were performance tested weekly by operating them under load for three hours at a time. Note that, to some extent, this weekly operation would itself be expected to condition the stacks and improve stack performance somewhat.
From the weekly testing, it was observed that the two stacks stored at −20° C. showed little to no voltage loss over seven months of storage and testing. The two cells stored at ambient showed stack voltage losses between about 0.1 and 0.33 V/month over 11 months of storage and testing. The several cells stored at 70° C. showed stack voltage losses of about 1.2 V/month over the first three months and then leveled off at a total stack voltage loss of about four volts thereafter over the total eight months of testing and storage. It was noticed that approximately ⅔ of the stack voltage loss was recovered over the three hours of testing (i.e., a significant but incomplete conditioning of the stack occurs over three hours of operation).
This example shows the temperature dependence of the performance (voltage) loss during storage and that the loss can be avoided by storing the fuel cell stack at suitably low temperatures.
While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, of course, that the invention is not limited thereto, except as by the appended claims, since modifications may be made by those skilled in the art without departing from the spirit and scope of the present disclosure, particularly in light of the foregoing teachings.
All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheetare incorporated herein by reference, in their entirety. | Certain fuel cells (e.g., solid polymer electrolyte fuel cells) may temporarily exhibit below normal performance after initial manufacture or after prolonged storage. While normal performance levels may be obtained after operating such fuel cells for a suitable time period, this process can take of order of days to fully complete. However, exposing the cathode to a reductant (e.g., hydrogen) can provide for normal performance levels without the need for a lengthy initial operating period. | 8 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to chemical analysis and cleansing of liquid streams and more particularly to liquid chromatography and wastewater treatment.
[0002] At present, liquid-phase chemical separations are usually performed in “columns” prepared by the packing of metal tubes with spherical beads that are composed of either silica or polystyrene and have diameters of 3 to 50 μm. The more or less inert beads provide solid supports that are chemically modified to produce a surface having targeted chemical characteristics. For example, in performing reversed-phase liquid chromatography, long carbon chains (C-18) can be affixed to the surfaces of the beads so as to produce a hydrophobic surface for the separation of non-polar organics. In some systems, beads can include particular surface polymers upon formation, precluding the necessity of post-formation modification of the materials.
[0003] Effective separations require dense packing of the beads into these columns to avoid dead-volume, which is any location within the column where turbulence can occur and interactions between molecules in the liquid and the surfaces of the beads are minimal. As a consequence of dense packing, high driving pressures (e.g., 2,000 to 5,000 psi) are required to overcome the backpressures that otherwise would prevent the liquid phase from moving through the densely packed columns.
[0004] Alternatively, highly porous “monoliths” are formed within the columns to generate high surface areas for interaction with the species that flow through the columns. Here, the high backpressures and a limited set of stationary phase chemistries can be restrictive. In the case of so-called “prep-scale” separations, the capital costs associated with producing large volume columns and the demands on the system hydraulics (i.e. pumps) are very high.
SUMMARY OF THE INVENTION
[0005] The present invention is generally directed to devices and methods for separation of species from a liquid mixture. For instance, in one embodiment, the invention is directed to a separation device comprising a monolithic cartridge that can be utilized for separating species from a mixture, for example as the stationary phase of a separation column in a high performance liquid chromatography (HPLC) process. In other embodiments, the devices may be useful in cap-LC, prep-scale separations, analytical separations, waste remediation/immobilization, extraction of selected organic molecules/ions from solution, purification of liquid streams (process waste, drinking water, pure solvents), selective extraction of cell matter and bacteria from growth media, or immobilization of cell matter and bacteria.
[0006] In general, the monolithic cartridges of the invention can include a plurality of nominally aligned polymeric fibers and can define capillaries between adjacent fibers such that the cartridge can exhibit macro-capillarity or bulk wicking action across the cartridge.
[0007] In one embodiment, at least a portion of the fibers in the cartridge can be bonded to adjacent fibers. For example the fibers can be physically, chemically, or pressure bonded at locations where adjacent fibers contact one another. In one particular embodiment, the fibers can be heat bonded at spaced locations throughout the monolithic cartridge.
[0008] Optionally, the monolithic cartridge can include a wrap that surrounds the fibers of the cartridge that can be disposed along the axial length of the aligned fibers. In one particular embodiment, a wrap surrounding the fibers can exert suitable radial pressure upon the fibers so as to press the individual fibers together and form capillaries between adjacent fibers without the necessity of physically or chemically bonding the fibers together. In one particular embodiment, wherein a fluid can be forced through the cartridge under pressure, the monolithic cartridge can include a wrap surrounding the fibers that comprises a nonporous material.
[0009] The polymeric fibers of the monolithic cartridges can be formed of any suitable polymeric material and can be of any suitable cross-sectional shape and size. For example, in one embodiment, the fibers can be nominally circular in cross-section. In another embodiment, the fibers can be configured with co-linear channels that run the length of the surface of each fiber. In addition, the monolithic cartridge can include a mix of different fibers. For instance, the monolithic cartridge can include fibers of different materials and/or different cross-sectional shapes and sizes.
[0010] If desired, the fibers can be modified so as to exhibit enhanced reactivity. In one embodiment, the fibers can be modified to exhibit enhanced attraction for a molecular species or family thereof that can be separated from a liquid during the process. For example, the fibers can be modified by protonation of the fibers, the addition of a chemical reactivity to the fibers, or through alteration of the hydrophobicity or ionic character of the fibers.
[0011] In another embodiment, the invention is directed to methods of separating a species from a fluid. For example, a fluid containing at least one molecular species can be moved through the capillaries of a monolithic cartridge, and the species can be separated from the fluid by chemical attachment of the species to the polymeric fibers in the cartridge.
[0012] The fluid can be moved through the cartridge according to any suitable method. For example, in one embodiment, the fluid can be pumped through the cartridge under pressure or can be moved through the cartridge via electro-osmosis methods as are generally known in the art. In another embodiment, the fluid can be moved through the cartridge by only the macro-level wicking action of the capillaries between the fibers. In another embodiment, the fibers can include surface-channeled fibers, and the monolithic cartridge can exhibit both micro-level wicking action through the surface-channels of the individual fibers as well as macro-level bulk wicking action through the capillaries between adjacent fibers.
[0013] In another embodiment, the disclosed invention is directed to a method for separating a mixture containing two or more proteins. In particular, it has been discovered that the channeled polymer fibers and monolithic cartridges disclosed herein can be utilized to separate biological macromolecular species such as proteins from a fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
[0015] FIG. 1 is a cross-sectional representation of a liquid analyte flowing through channeled fibers placed in a single column formed by a 0.25-inch (about 4.5 mm) diameter tube.
[0016] FIG. 1A is an expanded view window showing the end-on shape of the fibers and the potential irregular packing of the fibers in the column of FIG. 1 .
[0017] FIG. 2A is a micrograph of an enlarged side view of an intermediate portion of a channeled polyester fiber such as may be used in a column of a chromatograph.
[0018] FIG. 2B is a micrograph of enlarged side views of end portions of two channeled polyester fibers such as can be used in a column of a chromatograph.
[0019] FIG. 3 is a micrograph of an enlarged side view of an intermediate portion of a channeled polypropylene fiber such as can be used in a column of a chromatograph.
[0020] FIG. 4A is a graphical presentation of the time variation of absorbance that is illustrative of the separation of three polyaromatic hydrocarbons (PAH) compounds by a column filled with channeled polypropylene fibers.
[0021] FIG. 4B is a graphical presentation of the time variation of absorbance that is illustrative of the separation of the same three PAH compounds shown in FIG. 4A , but by a column filled with channeled polyester fibers.
[0022] FIG. 5A is a graphical presentation of the time variation of absorbance that is illustrative of the separation of three lead-based compounds by a column filled with channeled polypropylene fibers.
[0023] FIG. 5B is a graphical presentation of the time variation of absorbance that is illustrative of the separation of the same three lead-based compounds shown in FIG. 5A , but by a column filled with channeled polyester fibers.
[0024] FIG. 6 is a graphical presentation of the time variation of absorbance that is illustrative of the separation of five lipid compounds by a column filled with channeled polyester fibers.
[0025] FIG. 7A is a graphical presentation of the time variation of absorbance that is illustrative of the separation of polyaromatic hydrocarbon compounds at different flow rates through a column filled with channeled polyester fibers.
[0026] FIG. 7B is a graphical presentation of the time variation of absorbance that is illustrative of the separation of lipid compounds at different flow rates through a column filled with channeled polyester fibers.
[0027] FIG. 8 is a scanning electron micrograph of a portion of a monolithic cartridge of the present invention.
[0028] FIG. 9 is a scanning electron micrograph illustrating the cross section of a monolithic cartridge of the present invention.
[0029] FIG. 10 graphically compares the effect of volume flow rate on resulting backpressure of three separation columns including various stationary phases.
[0030] FIG. 11 illustrates the separation of a mixture of proteins utilizing a separation column comprising surface-channeled polymer fibers as described herein.
[0031] FIG. 12 illustrates the separation of a mixture of proteins utilizing a monolithic cartridge of the present invention.
[0032] FIG. 13 graphically compares backpressures at various flow rates for a column before and after the application of radial compression to the column.
[0033] The same numerals designate the same or like components throughout the drawings and description.
DETAILED DESCRIPTION
[0034] Reference will now be made in detail to various embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents.
[0035] As shown in FIG. 1 , bundles of surface-channeled polymer fibers 20 are packed into a column 22 that is formed by a tube having a uniform circular inside diameter of 0.25 inches and a length of 12 inches. The dimensions of the column 22 can be any size that is used in the practice of chromatography. Desirably, the length of each fiber 20 is substantially the same as the length of the column 22 and is disposed to extend within the column 22 over substantially the entire length of the column 22 . However, fibers 20 that have lengths that are shorter than the length of the column 22 may be used, but are not preferred. Moreover, an individual column can include fibers of various lengths.
[0036] FIG. 1 also includes an inset at 1 A that illustrates one possible embodiment of the surface-channel fibers. As shown schematically in cross-section in the expanded view window of FIG. 1A , each fiber strand 20 has six co-linear channels 24 extending the entire length of the exterior surface of the fiber 20 . Each channel 24 is defined by a pair of opposed walls 25 that extend generally and longitudinally and form part of the exterior surface of the fiber 20 . Desirably, these channels 24 and walls 25 extend down the entire length of the fiber 20 parallel to the longitudinal axis of the fiber 20 and are nominally co-linear on each fiber 20 . This produces de facto substantially the same co-linear channels 24 along the entire length of the column 22 . It should be understood that the particular shape of the embodiment of the surface-channeled fibers illustrated in FIGS. 1 and 1 A is not a requirement of the present invention. For instance, the number and/or cross-sectional shape of the channels can vary from that shown in the figures in other embodiments.
[0037] In an alternative embodiment, the channels 24 can be configured to wrap around the length of the fiber 20 in a helical fashion. However, as substantially all of the channels 24 can be nominally co-linear on each fiber 20 , substantially all of the channels 24 of the fibers 20 within each column 22 can follow a helix pattern that has the same pitch. The pitch is the number of complete turns of the channel 24 around the circumference of the fiber 20 per unit of length of the fiber 20 . This also produces de facto substantially the same co-linear channels 24 along the entire length of the column 22 .
[0038] Additionally, in the course of packing the fibers 20 into a bundle that lays along the entire length of the column 22 , whether the individual fibers have purely linear channels 24 or helical ones, it is possible that one or more, even all, of the fibers 20 in the bundle will rotate about its/their own axis or the axis of the column 22 over the entire length of the column. In other words, the surface-channeled fibers 20 may twist as they lay from one end of the column 22 to the opposite end. Accordingly, the channels 24 and walls 25 also may twist somewhat.
[0039] In some embodiments of the present invention, a device can be provided to move fluid through the column 22 and thus through the channels 24 of the fibers 20 . A pump (not shown) is typically provided for this purpose. The flow of liquid through the column 22 is schematically indicated by the arrows designated by the numeral 26 in FIG. 1 . A portion of the column 22 is cut away in the view shown in FIG. 1 for the purpose of illustrating the flow of liquid 26 through the column 22 along the fibers 20 arranged with their longitudinal axes parallel to the longitudinal axis of the column 22 . The nominal diameter of each fiber 20 desirably ranges 10 to 80 micrometers.
[0040] In general, any method for moving the fluid through the column 22 as is generally known in the art may be utilized. For example, in other embodiments, electro-osmosis or any other suitable hydro-dynamic means may be utilized to move fluid through the column 22 .
[0041] However, in some applications, the movement of the fluid may be effected without a device that is separate from the fibers themselves. In such embodiments, the fluid can, in one embodiment, move through the channels 24 of the fibers 20 solely by capillary action of the channels 24 of the fibers 20 . In other embodiments of the invention, discussed in detail below, the fluid can move through the column with macro-level capillary action between the fibers in addition to or alternative to the micro-level capillary action through the channels 24 of the individual fibers 20 .
[0042] Advantageous in the use of these channeled polymer fibers 20 as stationary phase materials, as compared to fibers having a more circular cross-sectional shape, is their higher surface area-to-volume ratios. Moreover, the shape and the number of channels 24 can be dependent on achieving the desired attribute of very high surface area-to-volume ratios. In this regard, helical channels 24 can pack more surface area than linear channels 24 and thus may be preferred, in some embodiments.
[0043] Another advantage of using channeled polymer fibers 20 in the disclosed processes is the fact that they generate very low backpressures (e.g., 500 to 1500 psi for linear channels 24 for normal chromatography flow rates (0.5 to 3 mL/min). The lower backpressure produced in the column 22 containing channeled polymer fibers 20 relative to the backpressure produced in the conventional column containing beads, is believed to be due to the parallel-running channels 24 . The ability to use fibers 20 of any desired length, while encountering relatively low backpressures, would suggest great potential for using columns 22 of these channeled polymer fibers 20 in prep-scale separations or for waste remediation in a variety of industries.
[0044] There are different fabrication approaches to form channeled polymer fibers 20 of the sort demonstrated here. In general, the process used to make these channeled, polymer fibers 20 is amenable to any polymers that can be spin-melted. For example, channeled fibers 20 may be melt spun from any of a number of different polymer precursors. A non-limiting list of exemplary materials from which the fibers of the invention can be formed can include polypropylene precursors, polyester precursors, polyaniline precursors, precursors composed of polylactic acid, and nylon precursors. Moreover, it should be understood that the polymeric fibers of the present invention can include surface-channeled fibers as well as fibers of other cross-sectional shapes, as will be discussed in more detail below. In general use, these channeled polymer fibers 20 tend to have a very strong wicking action for a variety of liquids, including water.
[0045] The ability to perform chemical separation of otherwise similar compounds for mixtures of polyaromatic hydrocarbons (PAHs), lipids, and organic and inorganic lead compounds has been demonstrated. This capability is particularly surprising given these seemingly chemically benign polymer compositions.
[0046] In one embodiment, the materials and devices of the present invention can be utilized for separations of mixtures containing macromolecular compounds, including biological macromolecular compounds. For example, separations of mixtures of proteins can be performed with the disclosed materials and devices.
[0047] FIG. 4A illustrates the separation of three different PAHs on a column filled with channeled polypropylene fibers (such as shown in FIG. 3 ). Similarly, FIG. 4B illustrates the separation of three PAHs on a column filled with surface-channeled polyester fibers (such as shown in FIGS. 2A and 2B ). As noted in FIGS. 4A and 4B , different relative concentrations of acetonitrile (ACN) to water were required to elute the solute species from the stationary phase and to obtain the chromatograms. Thus, gradient elution methods (i.e., changes in solvent composition) may be employed to elute the solute species from the stationary phase and to obtain the chromatograms. This is direct evidence of chemical interactions between the analyte molecules and the polymer fibers; as opposed to a more physical and mechanical “filtering” mechanism of retention of the species on the surfaces of the fibers 20 .
[0048] Different from the use of channeled polymer fibers 20 for the filtration of particulate matter in liquid and vapor streams, the use of channeled fibers 20 as proposed here is clearly based on chemical interactions between the analyte/solutes and the surfaces of the polymer fibers 20 . The fact that solvent gradients are required to separate the compounds as depicted in FIGS. 4A and 4B clearly demonstrates that this is the case. For example, the mixture of PAH's is completely immobilized on the polypropylene surface in aqueous solution to the point where the acetonitrile (ACN) concentration makes up 30% of the solvent composition. The same separation using polyester fibers as the stationary phase requires a 60% ACN to 40% H 2 O mixture; proving that the two polymers behave differently.
[0049] Liquid chromatography itself is based on the relative distribution between the solid and solution phases, and so relative retention characteristics are an excellent indicator of the actual interactions. The use of different combinations of polymer stationary phases, analyte/solutes, and mobile phases provides empirical insights into the retention processes. In order to obtain more specific thermodynamic information about the attraction of solutes to the fibers, atomic force microscopy (AFM) can be employed to probe the surfaces. In particular, AFM probe tips having different chemical modifications (e.g., polar, hydrophobic, etc.) can be used to study the interactions. The AFM can be used to simply determine the attractive forces under different solvent conditions. However, no imaging of the surfaces is required per se.
[0050] FIG. 5A illustrates the use of a column packed with channeled polypropylene fiber to separate three species of lead-based compounds. Similarly, FIG. 5B illustrates the separation of the species of these same three lead-based compounds using a column packed with channeled polyester fiber. The vertical axis in each of FIGS. 5A and 5B is a measure of the absorbance of light at 254 nanometers by each species. The greater the absorbance of that light, then the higher the number of absorbance units (AU) that is recorded on the chromatogram. The horizontal axis is the time axis that measures how long it takes for the majority of the species (the peak) to be detected by the absorbance of the light at 254 nanometers. Referring to FIG. 5A for example, the chlorotriphenyllead species shows a peak reading of about 0.06 absorbance units (AU's) of light at 254 nanometers at 5 minutes after the 0.02 milliliter volume of solution containing the chlorotriphenyllead species was introduced into the column that was packed with the channeled polypropylene fiber.
[0051] FIG. 5A illustrates that the lead nitrate species has less of a strong interaction with the polypropylene fibers in the column than either the chlorotriphenyllead species or the lead (II) phthalocyanine. The lead nitrate peak (though barely above zero) occurs earlier in time than either of the peaks of the chlorotriphenyllead species or the lead (II) phthalocyanine species. Of the three lead-based species tested, the lead nitrate species has the least affinity for the polypropylene fibers in the column. Moreover, the lead nitrate species has a different affinity for the polypropylene fibers in the column because the lead nitrate species has a different chemistry than each of the chlorotriphenyllead species and the lead (II) phthalocyanine species.
[0052] Since FIGS. 4A, 4B , 5 A, 5 B, 6 , 7 A and 7 B are based on absorbance of light at a particular wavelength, the peak height of each species doesn't necessarily reflect the relative concentrations of each of the species because each of them absorbs that wavelength with different strengths.
[0053] FIGS. 7A and 7B demonstrate the role of the rate at which the volume of liquid is pumped through the column 22 . In general, some of the peaks for the individual species are bigger at the low flow rates than for the high rates of flow through the column. However, the actual ability to discern one peak from another peak is as good if not better at the high rates of flow through the column than at the low flow rates. This latter finding concerning resolution of the individual peaks is counter to that observed with conventional column structures. Thus, the columns of the present invention do not necessarily exhibit degradation of the resolution of the chromatograms at the higher flow rates among those that were tested.
[0054] The surface-channeled polymer fibers 20 lend themselves to use in a variety of separation methods. In one embodiment, a bundle composed of a plurality of surface-channeled polymer fibers 20 can be disposed with a first set of the ends of the fibers 20 inserted into a first source of a fluid containing at least one species. The second ends of the fibers 20 (the ends opposite the first ends) can be disposed at a remote location that is apart from the location of the first source of fluid. The capillary action of the channels 24 will then transport the fluid from the source to the remote location at which point the transported fluid can be collected in a collection device, e.g., a beaker, a vile, a vat, or any container suitable to the specific process. During the course of the transport, some of the species will attach to the surfaces of the fibers 20 . The species that attach to the surfaces of the fibers 20 are removed from the fluid that reaches the remote location. Accordingly, the concentration of the species at the second location becomes reduced as a result of separation of the species from the fluid by chemical attachment of the species to the surface-channeled polymer fibers 20 .
[0055] In another embodiment, a bundle composed of a plurality of surface-channeled polymer fibers 20 can be dipped into a fluid containing at least one species. Capillary action will draw a portion of the fluid into the channels 24 . During the duration of the immersion of the fibers 20 in the fluid, some of the species will attach to the surfaces of the fibers 20 . The concentration of the species in the portion of the fluid that has been drawn into the channels 24 and collected in a collection device becomes reduced as a result of separation of the species from that portion of the fluid by chemical attachment of the species to the polymer fibers 20 . After a predetermined duration of immersion, the fibers 20 can be withdrawn from the fluid. The species that remain attached to the surfaces of the fibers 20 are thus removed from the fluid. Accordingly, the concentration of the species that remains in the fluid becomes reduced as a result of separation of the species from the fluid by chemical attachment of the species to the surface-channeled polymer fibers 20 .
[0056] It may be possible to use a single fiber in a micro-scale separation according to one embodiment of the present invention. Such as, for example, in a lab-on-a-chip separation process. In such micro-scale processes, fluid movement could be achieved by, for example, capillary, hydro-dynamic or electro-osmosis means.
[0057] Studies are proposed to further evaluate the potential of using channeled polymer fibers in analytical and prep-scale separations. The actual experimental procedure will involve a three-prong approach including: 1) development of column packing methodology, 2) use of atomic force microscopy to study the chemical basis of chemical specificity, and 3) investigations into on-column derivatization of the base polymer fibers.
[0058] The preliminary studies involve manual packing of the polymer fibers into the tubing columns 22 as depicted schematically in FIG. 1 . The tubing material can be any suitable material. In one embodiment, it can be a metallic tubing, such as steel, though any other suitable tubing material can be utilized including glass, ceramic, or polymeric materials. As shown in FIG. 1A , the illustrated columns 22 have appreciable amounts of dead volume along the flow axis. The quality of any subsequent chemical separation can depend at least in part on the uniformity of the packing of the stationary phase (fibers 20 ) in the column 22 with regards to dead volume, i.e., where turbulence can occur and molecule-surface interactions are absent.
[0059] High quality, reproducible columns 22 are required to adequately study the underlying mechanisms of retention. For instance, in one embodiment, radial compression technologies can be employed to effect more uniform packing of the fibers 20 . For example, radial compression can be applied to pack the fibers through utilization of water pressure, heat shrinking technologies, mechanical compression techniques, e.g., mechanical drawing or extrusion processes or any other radial compression method as is generally known in the art. For instance, in one embodiment, the column can be surrounded with tubing formed of polyethylene (PE), and the resulting wrapped column 22 then can be surrounded by a water jacket. Increases in pressure applied to the jacket can squeeze the polyethylene column 22 and thus compress the fibers 20 into a tighter bundle. Chemical separations of model compound classes can be performed to assess the role of compression on the retention qualities of the different fibers. Particular attention can be paid to the trade-offs between packing density, the obtained resolution, and the backpressure required to provide the desired flow through the column 22 .
[0060] In one embodiment, the present invention is directed to monolithic cartridges that can be utilized as a stationary phase in liquid separations. In particular, the monolithic cartridges include capillaries between adjacent fibers that can provide bulk wicking action in the disclosed cartridges. For purposes of this disclosure, the term ‘monolithic’ is herein defined to refer to a component formed of a plurality of units (i.e., two or more units) acting as a single, substantially rigid, uniform whole.
[0061] In one embodiment, the monolithic cartridges of the present invention can include nominally aligned fibers that have been bonded, pressed, or fused together at one or more locations along the fiber length. For example, in one embodiment, the monolithic cartridge can include two adjacent fibers that can be bonded along the entire length of one of the fibers. In another embodiment, two adjacent fibers in the cartridge can be bonded at a single site along their lengths, for instance merely a spot bonding between the fibers where they briefly contact one another. Similarly, two fibers can be bonded, pressed, or fused to each other at multiple spaced locations along their lengths. Moreover, while the monolithic cartridges of the present invention can include individual fibers bonded, pressed, or fused to one another, it should be understood that it is not a requirement of the invention that all of the fibers within the monolithic cartridges be bonded, pressed, or fused to another. The disclosed monolithic cartridges can include fibers that are not bonded to another. The monolithic cartridges of the present invention require only suitable inter-fiber interaction such that the cartridge is monolithic as herein defined, that is, such that the fiber bundle acts as a single, substantially rigid, uniform whole and exhibits bulk wicking action.
[0062] Among other advantages, bonding, pressing, or fusing polymeric fibers together within the fiber bundle can form capillaries between adjacent fibers so as to provide the bulk capillarity to the cartridges of the present invention. In addition, physical interaction among fibers can help to prevent the formation of dead volume within the column, as well as improve molecule/surface interaction along the length of the cartridge.
[0063] In one embodiment, the monolithic cartridges of the present invention can include surface-channeled fibers such as those described above. According to this embodiment, the monolithic cartridge can exhibit both micro-level capillarity due to the wicking capabilities of the individual channels along each fiber length as well as macro-level capillarity between adjacent fibers of the monolithic cartridge. In addition, monolithic cartridges including surface-channeled fibers can exhibit very high surface area for interaction between the stationary phase and the liquid phase during separation processes.
[0064] The monolithic cartridges of the present invention are not limited to those formed of capillary-channeled fibers, however. In one embodiment, fibers having a substantially circular cross-section can be used to form the disclosed cartridges. For example, in one embodiment, a fiber bundle of circular fibers can be physically or chemically bonded together at spaced locations throughout the bundle to form a monolithic cartridge that can exhibit bulk wicking action through the capillaries between adjacent fibers.
[0065] FIG. 8 is a scanning electron micrograph of a monolithic cartridge according to the present invention including a plurality of nylon fibers having nominally circular cross-sections. As can be seen, the fibers within the bundle are nominally aligned with one another. In addition, the bundle includes points or lengths of bonding 30 between adjacent fibers 34 .
[0066] FIG. 9 is a scanning electron micrograph of a similar monolithic cartridge formed of polyester fibers and shown in cross-section. The figure shows the regions of porosity 32 between individual fibers 34 , which provide the bulk or macro-level capillarity to the cartridge. The points of bonding 30 between individual fibers can also be seen in FIG. 9 .
[0067] In general, any suitable method that promotes the formation of the fiber bundle as a single, substantially rigid, uniform whole cartridge while defining capillaries between individual fibers to provide bulk wicking action to the cartridge can be utilized. For instance, the individual fibers of a monolithic cartridge can be bound one to another with either physical or chemical bonds. Moreover, the preferred method for bonding, pressing, or fusing adjacent fibers within any particular cartridge can generally vary depending primarily on the fiber material.
[0068] For example, in some embodiments, individual fibers can be formed of a thermoplastic polymer such as polyester or polypropylene that is amenable to melt-spinning formation processes. According to one embodiment, following formation of such individual fibers, a plurality of the fibers can be heat bonded to form the monolithic cartridges of the invention. For instance, a plurality of fibers can be passed through a steam chest or heating cabinet and brought to a temperature at or above the softening temperature of the fiber material in order to physically heat bond adjacent fibers to one another at points of contact along the fibers. Particular examples of processes that can be utilized for forming bonded fiber bundles such as those of the present invention are further described in U.S. Pat. No. 4,996,107 to Raynolds, et al. and U.S. Pat. No. 6,616,723 to Berger, both of which are incorporated herein by reference.
[0069] In other embodiments, bonding agents can be utilized in forming the disclosed cartridges. For example, in one embodiment, at least some of the fibers contained in the cartridges can include a bondable material either integral to or topical to the fibers. Following any necessary activation of the bondable material, the fibers including the bondable material can bind to adjacent fibers at points of contact within the fiber bundle, leaving capillaries between the fibers and throughout the length of the fiber bundle. Bondable materials can include, for example, cross-linking agents applied to the individual fibers or functional moieties included on some or all of the polymers forming the fibers.
[0070] In some embodiments of the present invention, the monolithic cartridge can include a wrap that can surround the fibers and disposed along the axial length of the fibers. According to this particular embodiment, actual physical or chemical bonding or fusion of the fibers within the cartridge may not be necessary, as the wrap material encasing the fibers can provide suitable pressure to the individual fibers within the cartridge so as to press adjacent fibers together and form the wicking capillaries between the adjacent fibers. According to this particular embodiment, wherein adjacent fibers are not necessarily fused together so as to form the disclosed wicking capillaries, the fibers can be considered to be pressure bonded. Of course, the term “pressure bonded” can also encompass embodiments wherein the pressure applied to the cartridge does lead to actual fusion of adjacent fibers. In addition, the presence of the wrap material around the fibers can provide the rigidity and unifying wholeness to the component parts of the monolithic structure without the necessity of forming physical or chemical bonds within the fibers.
[0071] For example, according to one embodiment, the fiber bundle of the cartridge can be encased in a polymeric wrapping material along the axial length of the fibers and radial compression can be applied to the cartridge by any suitable means. Upon application of radial compression, the radial dimension of the cartridge can decrease as the fibers are pressed together and the wicking capillaries form between fibers. Thus, a bulk wicking capillary network can develop in the cartridge between the adjacent fibers. Referring to FIG. 13 , backpressure vs. flow rate data is illustrated for a column comprising a plurality of surface-channeled polymer fibers before (at 50 ) and after (at 52 ) the application of radial compression to the column. More specifically, a column of surface-channeled polypropylene fibers wrapped with a polymeric outerwrap was formed. The column (100×0.13 cm i.d.) was then drawn through an orifice to compress the column wall. As can be seen, following compression, the backpressure of the column (now 100×0.10 cm i.d.) has increased over the undrawn column at identical flow rate, due to the decrease in void fractions between the adjacent fibers within the column.
[0072] In one embodiment, the monolithic cartridges of the invention can include a nonporous wrap encasing the cartridge along the axial length of the fibers. For instance, when considering standard liquid chromatography systems and techniques, in which liquid is pumped or otherwise forced through the bundle, the monolithic cartridge can be encased in a nonporous wrap such as a suitable metallic or polymeric wrap material.
[0073] In other embodiments, the monolithic cartridges of the invention do not require a nonporous wrap. For example, in those embodiments in which liquid moves across the cartridge via capillary action alone, e.g., lateral flow assay applications or thin layer chromatography systems, the plurality of fibers can include physical and/or chemical bonds between the fibers to form the wicking capillaries and the cartridge need not include an outer wrap material at all. Optionally, in another embodiment, the cartridge can include a wrap of a porous material surrounding the length of the fibers to provide uniformity and rigidity to the monolithic structure, and, in some embodiments, providing pressure bonding between the fibers.
[0074] The monolithic cartridges of the present invention can not only exhibit good bulk capillarity, allowing relatively high volume flow rates through the cartridges, but can do so at lower backpressures than those attainable for previously known packed particular separation columns. Moreover, in those embodiments wherein the monolithic cartridge includes surface-channeled polymer fibers, the micro-level wicking properties of the individual fibers can add to the bulk wicking properties of the cartridge as well as providing higher surface area per unit volume and thus can further improve mass transfer and separation characteristics of the disclosed systems. As such, standard liquid chromatography columns utilizing the disclosed monolithic cartridges can be operated lower instrumentation overhead, which can translate to lower operational costs. For example, referring to FIG. 10 , backpressure was graphed at various flow rates for a column of 4.6 mm inner diameter and 305 mm in length utilizing three different stationary phases. As can be seen, backpressures obtained for the monolithic cartridges of the present invention, shown at 40 , are considerably lower than those for a commercial C 4 -derivatized silica packed-particulate column, shown at 42 , as well as for a commercially available phenyl-derivatized packed particulate column, shown at 44 . For instance, in one embodiment of the present invention, separation processes can be run at flow rates up to about 6 mL/min at backpressures of less than about 1200 psi.
[0075] In one embodiment, the monolithic cartridges of the present invention can be fairly rigid structures (i.e., capable of sustaining the overall shape of the structure under normal processing and handling conditions). This can greatly simplify handling and processing of the disclosed materials. In addition, the disclosed monolithic cartridges can be formed into any desired size and shape. For example, the monolithic cartridges can be manufactured with any predetermined dimensionality and utilized in existing chromatographic systems by merely mounting the monolithic cartridge in place of the conventional chromatographic column of the system.
[0076] Future investigation of the disclosed devices and methods will seek to take the basic chemical principles governing packing density and the chemical basis of chemical specificity and begin to tailor the surfaces of the polymer fibers in such a way as to have specificity for particular classes of chemical compounds. The preliminary studies have demonstrated that polyester and polypropylene fibers have different surface chemistries, though each nominally has what is termed reversed-phase character. That is to say that each has a propensity to bind non-polar molecules. As mentioned previously, a number of other base polymers could be fabricated as disclosed to gain access to other degrees of chemical specificity.
[0077] Additionally, the surfaces of the polymer fibers could be modified, while maintaining the high surface area-to-volume ratio and the basic structure. Applications in analytical separations for a wide range of compound classes are anticipated by changing the identity of the base fiber or performing chemical derivatization of the surfaces of the fibers. At least portions of the surfaces of the polymer fibers can be modified to a predetermined chemical reactivity. For example, the predetermined chemical reactivity could be obtained by modifying at least portions of the surfaces of the polymer fibers to a predetermined level of hydrophobicity. Thus, active sites on the fiber surfaces could be functionalized to gain more or less hydrophobic character. The predetermined chemical reactivity also could be obtained by modifying at least portions of the surfaces of the polymer fibers to a predetermined ionic character. For example, the surfaces of fibers formed from polyvinyl alcohol (PVA) might be protonated in situ by an acidic mobile phase to produce an ion exchange column.
[0078] High performance liquid chromatography will be used as the first-level screening tool in the characterization. This work will not only focus on chemical separations, but also on the capacity to retain on-column target waste species of relevance to a wide range of industries (i.e., how much solute can be immobilized in a fiber ‘cartridge’?). This latter aspect is the most relevant characteristic in terms of using these fiber-types in waste stream treatment strategies.
[0079] The disclosed invention can be further understood with reference to the following Examples.
EXAMPLE 1
[0080] Channeled propylene fibers having nominal diameters of approximately 50 μm and 8 branched channels running along their length were examined for protein separations. The channeled fibers were obtained from Eastman Chemical, Kingsport, Tenn. from a bobbin of fibers measuring more than 1000 meters in length.
[0081] Bundles of approximately 1200 fibers were loaded co-linearly into 4.6 mm i.d., 306 mm long stainless steel tubing (available from Valco Instruments, Houston, Tex.). Bundles were passed through the column such that the general alignment of the fibers within the column was longitudinally parallel such that broadening due to eddy diffusion, i.e., tortuous paths, was expected to be minimal.
[0082] The fiber lengths were trimmed to be flush with the tubing ends, and the column ends were sealed with 0.75 mm thick, 6.35 mm diameter frits including 10 μm pores and completed with column end fittings (available from Valco Instruments). Each fiber column had a packing mass of about 1.7 grams. Column porosity determinations for the polypropylene fiber columns yielded values of approximately 0.66. The columns were flushed repeatedly with organic solvent (methanol and acetonitrile) and distilled water.
[0083] The chromatographic system consisted of a Waters (Milford Mass.) Model 600S HPLC pump with a 6 port Rheodyne injection valve (Rohnert Park, Calif.) fitted with a 10 μL injection loop. The prepared columns were mounted in place of conventional columns in the system. A Waters 2487 dual wavelength absorbance detector was employed at 216 nm, and the separations were performed at a solvent flow rate of 1.5 mL/min.
[0084] HPLC-grade water (Fisher Scientific, Pittsburgh, Pa.) was used for the preparation of the protein solutions. Each protein stock solution was prepared as a 1 ppm solution using 5:95 (ACN-water) containing 0.1% TFA. The four proteins and the TFA used in the mobile phase were purchased from Sigma Aldrich (Milwaukee, Wis.). Particular proteins were superoxidase (SOD) from bovine erythrocytes (EC No. 232-943-0), myoglobin from horse skeleton muscle (EC No. 309-705-0), hemocyanin from human, and hemoglobin from horseshoe crab. The mobile phase was prepared from HPLC-grade ACN, water, and 2-propanol. The protein test solutions were stored at 6° C.
[0085] The protein test mixture was prepared by mixing 2 mL of each protein stock solution in a 20 mL vial. The column was rinsed with mobile phase 95:5 water and (1:1) propanol-acetonitrile for 10 minutes before each injection. The separation was achieved using a gradient elution of 95:5 to 35:65 water containing 0.1% TFA (v/v)-propanol/ACN (1:1) (containing 0.085% TFA) over 70 minutes at 1.5 mL/min.
[0086] The gradient elution chromatogram of the mixture is shown in FIG. 11 . Table 1, below, summarizes the basic characteristics for the separation. As seen in the Figure, each of the peaks is very well resolved and quite symmetric in profile and the elution order does not correspond to the analyte molecular weights (31.2, 60, 75, and 17 kDa, respectively).
TABLE 1 Retention Retention Selectivity Peak Protein Time Factor Factor half-width Resolution Asymmetry PC SOD 7.5 2.3 — 0.95 — 1.4 4.6 Hemoglobin 12.4 4.4 1.9 0.86 1.4 1.09 8.5 Hemocyanin 18.3 6.9 1.6 0.85 1.6 1.08 13 Myoglobin 31 12.5 1.8 0.99 2.9 1.05 18
EXAMPLE 2
[0087] A monolithic cartridge of heat-bonded polyester fibers having substantially circular cross-sections was utilized to selectively separate solutions including the proteins ribonuclease A and cytochrome C. The solvent gradient was varied from 80:20 (water (0.1% TFA):acetonitrile(0.06% TFA)) to 70:30 over 10 minutes at a liquid volume flow rate of 1.75 mL/min. Systems and methods used for the separations were similar to those described in Example 1, above. Three separations of 20 μL injections were performed. Results of the separations are graphically illustrated in FIG. 12 . As can be seen, the three injections yielded very reproducible separations.
[0088] While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. | Monolithic cartridges including a plurality of nominally aligned polymer fibers can be used as stationary phase materials for liquid chromatography separations. Bundles of fibers are packed together so as to form capillary channels between the fibers. Different polymer compositions permit the “chemical tuning” of the separation process. The fibers can be physically or chemically bonded at spaced locations throughout the cartridge or can be packed together under pressure by use of an encasing wrap to form the capillary channels. Use of fibers allows a wide range of liquid flow rates with very low backpressures. Applications in HPLC, cap-LC, prep-scale separations, analytical separations, waste remediation/immobilization, extraction of selected organic molecules/ions from solution, purification of liquid streams (process waste, drinking water, pure solvents), selective extraction of cell matter and bacteria from growth media, and immobilization of cell matter and bacteria are envisioned. | 1 |
BACKGROUND OF THE INVENTION
The present invention is directed to roll handling apparatus and, more specifically, to a roll handling apparatus which allows an operator in a roll converting industry to quickly and easily transport and sort rolls from production to, for example, a pallet.
Various materials, such as paper and soft metals, are slit and placed on rolls at a roll converting station. It has been found that the materials within the rolls are sometimes damaged if, for example, the rolls are rolled on their circumference. A common delivery system for the rolls is to vertically align them in groups on a pallet and then transport the pallets to remote locations, where the individual rolls are removed and utilized. It is important that the rolls be quickly and accurately vertically aligned.
SUMMARY OF THE INVENTION
The present invention is directed to a roll handling apparatus which includes an elevated support rail which extends from the slitter/winder location to a palletizing location. A C-hook assembly, for example, a prior art Automatic Handling/Bucon Levomat unit, is mounted for movement along the support rail. The C-hook assembly includes a travelling support mounted for movement along the rail. A vertically movable lifting arm extends downwardly from the travelling support and a C-shaped lifting hook is mounted adjacent the lower end of the lifting
A tiltable upender assembly is positioned adjacent one end of the support rail. The upender assembly includes a support deck. Opposed gates are positioned adjacent the opposite sides of the deck and a pivotable carrier assembly extends generally between the opposed gates. A lift mechanism is provided for tilting the deck such that one side of the deck is higher than the other side. A pivot cylinder is provided for pivoting the carrier assembly and the deck. This moves the rolls which have been positioned on the deck through a 90° rotation and aligns them in a correct vertical position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view showing the roll handling apparatus, according to the present invention;
FIG. 2 is an end view showing the upender assembly, according to the present invention;
FIG. 3 is an elevational view showing the upender assembly of FIG. 2;
FIG. 4 is a plan view of the upender assembly shown in FIG. 2;
FIG. 5 is a fragmentary end view of a portion of the upender shown in FIG. 2;
FIG. 6 is a partial diagrammatic end view of the upender assembly, according to the present invention, with a pallet positioned on the upender assembly;
FIG. 7 is a view similar to FIG. 6 showing the movable gate positioned inwardly;
FIG. 8 is a view similar to FIG. 6 showing the deck tilted prior to receiving rolls;
FIG. 9 is a view similar to FIG. 6 showing rolls positioned on the deck between the opposed gates and adjacent the pallet;
FIG. 10 is a view similar to FIG. 9 showing the deck returned to a horizontal position;
FIG. 11 is an elevational view of the upender assembly, shown in FIG. 6, and showing the deck and the rear carrier assembly pivoted 90° to position the rolls in a vertical position;
FIG. 12 is a view similar to FIG. 11 after extension of the pivot link cylinders and showing the pallet moved to the right, as shown in FIGS. 11 and 12;
FIG. 13 is a top plan view of the upender assembly shown in FIG. 12 and showing the pivotal gate rotated outwardly; and
FIG. 14 is a view similar to FIG. 13 showing the pallet supporting the vertically aligned rolls moved outwardly away from the carrier assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A roll handling apparatus, according to the present invention, is generally indicated by the reference number 15 is FIG. 1. Rolls, in this embodiment paper rolls 16, are positioned on a cart 17 at the location where the slit rolls are discharged from the slitter/winder station. While the rolls 16 in the present embodiment are paper rolls, other types of rolls or rolled materials may also be handled by the roll handling apparatus 15, according to the present invention. In addition to paper, the rolled material may be malleable metals or plastic films.
It has been found that improper handling of the rolls 16, for example rolling the rolls 16 on their circumference, often result in product damage. The roll handling apparatus 15 provides a simple, fast sorting and palletizing process which eliminates product damage and also minimizes the labor required.
The roll handling apparatus 15 includes an elevated support rail 19 which is mounted on vertical support frames 20. The support rail 19 generally extends between the cart 17 at the slitter/winder location and a tiltable upender assembly 21, which is a part of the present invention. The roll handling apparatus 15 includes a C-hook assembly 22. The C-hook assembly 22 is of a prior art design, for example, an Automatic Handling/Bucon Levomat Unit. The hook assembly 22 includes a travelling support 23 having wheel units 24 which are carried by the elevated support rail 19. A vertically movable lifting arm 25 extends downwardly from the travelling support 23. A C-shaped lifting hook 26 is mounted adjacent the lower end of the lifting arm 25. The C-hook 26 includes a probe 27 which is mounted within the central opening 28 of a roll 16.
Referring to FIGS. 1-4, the tiltable upender assembly 21 includes a base unit 29 having a pair of opposed side frame members 30 which rest on transverse supports 31. Referring to FIG. 2, the transverse supports 31 include "V" slots which receive the side frame members 30. The upender assembly 21 includes a pair of generally "L-shaped" support members 33 having perpendicular legs 34 and 35. The L-shaped support members 33 are pivotally connected by opposed pivot shafts 37 to the side frame members 30 (see FIG. 3). A rear carrier assembly 39 is mounted by a plurality of links 40 to the legs 35 of the L-shaped support members 33. Link cylinders 41 are connected to the links 40. Actuation of the link cylinders 41 provides relative motion between the legs 35 and the rear carrier assembly 39 to move the carrier assembly 39 away from the pivot shaft 37.
A pair of cylinders 42 are operatively connected between the L-shaped support members 33 and the side frame members 30. The cylinders 42, when retracted, pivot or rotate the rear carrier assembly 39 downwardly to the dashed line position 39' indicated in FIG. 3.
The rear carrier assembly 39 includes a pair of main frame members 44 which are connected by the links 40 to the opposed legs 35 of the L-shaped support members 33. A longitudinally extending flange member 45 is mounted on the main frame members 44 at their upper ends and an angle member 46 is mounted on the main frame members 44 at their lower ends (see FIG. 3). A motor and gear reduction assembly 48 is mounted on the flange member 45. A support box 50 is mounted below the flange member 45 adjacent the upper ends of the main frame members 44. A plurality of driver rollers 52 are mounted for rotation between the flange member 45 and the lower angle member 46. The drive rollers are driven by a drive chain 53, which in turn is driven by the output shaft 54 of the motor and gear reduction assembly 48. A plurality of idler rollers 55 extend between the support box 50 and the lower angle member 46. The idler rollers 55 are generally interposed between adjacent ones of the drive rollers 52.
Referring to FIG. 2, a deck assembly 56 including an upper deck 57 is fixably mounted on the legs 34 of the L-shaped support members 33. The deck assembly 56 includes a plurality of channel box members 58 which define the outer perimeter of the deck assembly 56 and which support the rectangular deck 57.
A series of cross plates 65 extend between the side frame members 30 and pivotally mount a pair of lift cylinders 66 (see FIG. 2). The lift cylinders 66 are positioned adjacent the pivoting gate 60 below the deck assembly 56. Extension of the lift cylinders 66 lift the deck assembly 56 to the tilted position shown in FIG. 8.
Opposed gates 60 and 61 are positioned adjacent opposite sides of the deck assembly 56. The gate 60 is pivotally mounted to the deck assembly 56 and is operatively connected to a pair of pivot cylinders 63. Extension of the pivot cylinders 63 move the gate 60 between the solid line position, shown in FIG. 2, and the dashed line position 60'.
Referring to FIG. 2, the movable gate 61 is mounted on a travelling carriage 68. The carriage 68 includes outwardly extending shafts which mount roller assemblies 69. The channel box members 58 mount a pair of guide plates 70 which support and define a path for the roller assemblies 69 of the carriage 68. Referring to FIG. 3, the deck assembly 56 includes a plurality of support members 71 which mount and support the deck 57. A drive block 72 having a threaded opening 73 is mounted adjacent the right end of the deck assembly 56, as viewed in FIG. 2. The drive block 72 is mounted between adjacent pairs of the support members 71. Referring to FIG. 2, a threaded shaft 75 extends through the center of the deck assembly 56 and is received by the threaded opening 73 of the drive block 72. A drive motor 76 is operatively connected to the threaded shaft 75. The drive motor 76 is a reversible motor. Operation of the motor acting through the threaded shaft 75 and through the drive block 72 moves the carriage 68 and the movable gate 61 toward and away from the opposed gate 60. Referring to FIG. 2, the gate 61 includes a front plate 79 which is supported by a pair of wings 80 having lower ends 81 which extend through slots in the deck 57. The ends 81 are mounted on the carriage 68. The gate assembly 61 also includes a plurality of ribs 83 which are located between the wings 80. Similarly, the pivotable gate 60 also includes a front plate 84 extending between opposed wings 85. The wings 85 include lower ends 86 which are pivotally connected to the respective rods of the pivot cylinders 63. The pivotable gate assembly 60 also includes a plurality of reinforcing ribs 87 which are located between the wings 85.
Referring to FIGS. 2 and 3, in the present embodiment, a pair of opposed racks 89 are mounted below the deck 57. A transverse shaft 90 of the carriage 68 mounts a pair of opposed pinions 91 which mate with the respective racks 89. The racks ensure that the carriage 68 and the attached movable gate 61 move along a predetermined path.
Referring to FIG. 3, a pallet 93 is indicated by dashed lines. As best shown in FIG. 5, a pallet support plate 94 is mounted between the legs 34 of the L-shaped support members 33. A pallet cylinder 95 and a pair of return spring assemblies 96 are mounted by the support plate 94. The rods of the pallet cylinder 95 and return spring assemblies 96 in turn mount a carrier plate 97 which mounts and supports a pallet deck 98. The pallet deck 98 includes an upper gripper surface layer 99.
Referring to FIG. 1 and FIGS. 6-14, in a typical operation, the operator uses the C-hook assembly to remove an individual roll 16 from the cart 17. The travelling support 23 moves along the elevated support rail 19. During this period, if desired, the operator can sort the rolls by size and also label the rolls. Prior to placing a roll 16 in the tiltable upender assembly 21 the view, as seen by the operator, is shown in FIG. 6. The pallet 93 has been placed in position against the rear carrier assembly 39. The pallet cylinder 95 has been actuated to move the pallet 93 to its FIG. 3. The lift cylinder 66 has been retracted to move the deck assembly 56 to its horizontal start position. The gate 60 has been pivoted upwardly to define a side of the roll receiving opening.
Referring to FIG. 7, the drive motor 56 is energized and the carriage 68 together with the attached movable gate 61 is moved to the left to form the other side of the roll receiving opening.
Referring to FIG. 8, the lift cylinders 66 are then extended to tilt the upender assembly 21. Referring to FIGS. 2 and 8, when the tilting occurs, the left hand side frame member 30 is moved upwardly, with the right hand side frame member 30 pivoting in the V-shaped slot 32.
Using the tiltable upender assembly 21 greatly facilitates the proper positioning of the rolls 16 in their desired alignments on the pallet 93. The force of gravity moves the initial paper roll unit 16 to the lower right hand corner. The next paper roll unit is placed to the left and gravity urges this paper roll 16 into a correctly aligned tight position with the first roll 16. Next, the upper right hand paper roll 16 is positioned and again, because of the tilted deck 57, urges the third unit to the right and downwardly. Lastly, the fourth roll 16 is placed in the remaining slot, again being urged downwardly by gravity. Paper rolls of various diameters and numbers can be placed within the tiltable upender assembly 21, according to the present invention. The stacking is not limited to the four roll design or the geometrical pattern shown in FIG. 9.
After the stacking of the rolls 16 is completed, the lifting cylinders 66 are retracted and the FIG. 10 position is achieved.
At this time, the main pivot cylinders 42 are actuated and the L-shaped support members 33 together with the deck 57, pallet 93 and rear carrier assembly 39 are rotated 90°, placing the rolls 16 in an upended vertical position, as shown in FIG. 11.
The next step is to move the upended rolls 16 outwardly to a remote location where they are transported to another job site or transported to another location in the factory. To provide sufficient clearance, the link cylinders 41 are actuated. Acting through the links 40, the carrier assembly 39 which is now supporting the pallet 93 and the paper rolls 16 is moved outwardly relative to the legs 35, as shown in FIG. 12.
At this time, the gate cylinders 63 are extended and the gate 60 pivoted outwardly 90° to the FIG. 13 position.
The pallet 93, supporting the properly aligned and upended rolls 16, is moved outwardly by actuating the motor and gear reduction assembly 48. The drive rollers 52 begin to rotate and move the pallet 93 and rolls 16 to a conveyor 101. In other embodiments, not shown, the pallet 93 is moved outwardly and is handled by other conveying means, for example by a fork lift.
The pivot cylinders 63 are then retracted swinging the gate 60 inwardly. The link cylinders are actuated to move the carrier assembly inwardly. The main pivot cylinders 42 are actuated rotating the deck 57 and the rear carrier assembly 90° to the FIG. 6 position. The drive motor 76 is energized and reversed to move the carriage 68 to the right, as viewed in FIG. 2. This moves the movable gate 61 to its beginning position, as shown in FIG. 6. Another pallet 93 is positioned on the pallet deck 98 and the roll handling apparatus 15, including the tiltable upender assembly 21, is in position for another operation.
Many revisions may be made to the above preferred embodiment and to the following claims without departing from the scope of the invention. | A roll handling apparatus for aligning and upending a plurality of rolls is disclosed. A C-hook is mounted on a vertical lifting arm. An elevated rail defines a path of travel for a travelling support which mounts the vertical lifting arm. A tiltable upender assembly is positioned adjacent the elevated rail and includes a deck assembly, opposed gates positioned on opposite sides of the deck assembly and a pivotable rear carrier assembly extending between the opposed gates. Lift cylinders are provided for tilting the deck assembly for correct alignment of the rolls. Pivot cylinders are provided for rotating the deck assembly and the carrier assembly ninety degrees to upend the correctly aligned rolls. | 1 |
BACKGROUND OF THE INVENTION
1. Description of the Field of the Invention
This invention describes additives for processing polyvinyl chloride compounds. The present invention is particularly concerned with calendering operations concerning such polyvinyl chloride compounds.
2. Description of the Art Practices
This invention, as previously noted, relates to the processing of polyvinyl chloride compounds. In particular, this invention is concerned with polyvinyl chloride compounds which are formed utilizing as a primary stabilizer organo-tin materials. It has been found necessary to utilize stabilizers in polyvinyl chloride products to scavenge hydrochloric acid which is formed by the thermal degradation of the polymer. The scavenged acid is converted by the organo-tin compound to the corresponding tin salt. The need to scavenge the hydrochloric acid arises because it further degrades the polyvinyl chloride product and in the absence of a scavenger, the rate of degradation is greatly accelerated by the presence of the hydrochloric acid. It has been found that the esters used herein provide low viscosity in processing of the melted polyvinyl chloride with no observable lower threshold on the amount of ester employed. That is, ordinarily internal lubricants do not function at less than 0.5 percent by weight of the polyvinyl chloride but that the present invention employes an ester which does reduce viscosity at lower concentrations.
Certain work concerning the partial esters of pentaerythritol for use in polyvinyl chloride resins is described in U.S. Pat. No. 4,220,570 issued Sept. 2, 1980 to Worschech et al.
Throughout the specification and claims, percentages and ratios are by weight and tempertures are in degrees Celsius unless otherwise noted. The terms pentaerythritol, tetrakis (hydroxymethyl) methane, and 2,2-bishydroxymethyl-1,3-propanediol are used interchangeably herein.
SUMMARY OF THE INVENTION
A process is described for manufacturing a polyvinyl chloride containing composition having therein a primary stabilizer which is an organo-tin compound to stabilize against the thermal degradation of the composition, the improvement therein comprising adding to such composition an effective amount of an internal lubricant to lower the melt viscosity during preparation of such composition said lubricant being partial fatty ester of 2,2-bishydroxymethyl-1,3-propanediol wherein said partial ester is about 20 percent to about 50 percent monoester, about 35 percent to about 65 percent diester, and about 10 percent to about 35 percent by weight triester said composition being substantially free of unreacted 2,2-bishydroxymethyl-1,3-propanediol and the tetraester wherein the ester is formed from a fatty acid having the following composition:
(a) 0 percent to 15 percent by weight 14 carbon saturated fatty acid;
(b) 0 percent to 10 percent by weight 15 carbon saturated fatty acid;
(c) 25 percent to 75 percent by weight 16 carbon saturated fatty acid;
(d) 0 percent to 10 percent by weight 17 carbon saturated fatty acid;
(e) 25 percent to 75 percent by weight 18 carbon saturated fatty acid; thereby lowering the melt viscosity during preparation of such composition.
Compositions are also described.
DETAILED DESCRIPTION OF THE INVENTION
The present invention, as previously noted, relates to the process of manufacturing a polyvinyl chloride compound containing therein a primary organo-tin stabilizer and a partial ester as more particularly described later which functions as an internal lubricant during a calendering operation and which also functions as a co-stabilizer.
The unique compound which functions as an internal lubricant and as a co-stabilizer in the organo-tin stabilizer polyvinyl chloride system is a partial ester of pentaerythritol as described below. The basic description of the partial ester is made in the Summary of the Invention and the reader is referred thereto.
The fatty acid distributions which have been found particularly useful are from about 0 percent to about 10 percent by weight of the 14 carbon fatty acid; from about 0 percent to about 8 percent of the 15 carbon fatty acid; from about 30 percent to about 70 percent of the 16 carbon fatty acid; from about 0 percent to about 8 percent of the 17 carbon acid and from about 30 percent to about 70 percent by weight of the 18 carbon acid. More preferably, the distribution of the acid chain lengths utilized in the partial ester are from about 1 percent to about 5 percent by weight of the 14 carbon fatty acid; from about 0.1 percent to about 5 percent of the 15 carbon fatty acid; from about 35 percent to about 55 percent of the 16 carbon fatty acid; from about 1 percent to about 5 percent of the 17 carbon fatty acid and from about 40 percent to about 55 percent by weight of the 18 carbon acid. The chain length of the fatty acid is essential to ensure that the proper internal lubricating effect is obtained. Higher or lower fatty acids give unpredictable lubricating effects and are thus not as useful as the blends described herein.
The partial ester of the pentaerythritol is so formed such that the partial ester will be substantially free of the unreacted pentaerythritol and substantial free of the tetraester. Neither of these compounds is particularly useful compared to the resultant mixture of partial esters which give both an internal lubricating and co-stabilizing effect. The partial ester is preferably so formed to provide from about 25 percent to about 45 percent by weight of the monoester; from about 40 percent to about 60 percent of the diester and from about 15 percent to about 30 percent by weight of the triester. More preferably, the ratio of the mono-, di- and tri-partial esters of pentaerythritol is from about 27 percent to about 35 percent by weight of the monoester; from about 45 percent to about 55 percent by weight of the diester; and from about 18 percent to about 23 percent by weight of the triester. It is particularly preferred that the foregoing composition as previously noted be substantially free of the tetraester. This compound, however, has been found to be capable of being present at levels of up to 5 percent by weight, preferably not greater than 3.5 percent by weight of the polyvinyl chloride compound without causing substantial difficulties in the processing.
It is also highly desired that the polyvinyl chloride compound be substantially free of fatty acids as these compounds may form soaps thereby leading to unwanted lubricating effect and lack of clarity in clear articles.
The tin compounds of the present invention are conveniently dioctyl tin and dibutyl tin and mixtures thereof. Other suitable organo-tin compounds which may be used in the present invention include: dimethyl tin and dilauryl tin all of which are usually used as the thioglycolate. The organo-tin is conveniently used at levels of 0.3 to 5 percent, preferably 0.5 to 2.5 percent by weight of the polyvinyl chloride compound.
The tin compounds are used to stabilize the cler polyvinyl chloride products used for example in blister packaging. The partial esters of the present invention are obtained by reacting the desired mixture of fatty acids with the pentaerythritol. It is highly preferred that the hydroxyl number of said compounds be in the range of 190 to 210 and most preferably from 195 to 205. The reaction to form the pentaerythritol esters as previously noted involves obtaining the desired fatty acid chain length mixture and thereafter reacting it with pentaerythritol. This reaction proceeds at a temperature of from about 140 degrees C. to about 220 degrees C. and is complete in about 3 to 8 hours. The pentaerythritol is added to a mixing pot containing the fatty acids while exercising control on the rate of reaction. By controlling the rate of reaction, it is assured that substantially all of the pentaerythritol present is converted to the monoester. Thereafter, the monoester is converted to the diester and higher esters.
The utilization of the compounds of the present invention as previously noted in particularly for calendering operations. Calendering is an operation where the polyvinly chloride resin is compressed between rollers and formed into sheets which are then formed into the desired article containing the polyvinyl chloride resin. As calendering operations are well known in the art, no particular description is given of the utilization of the compounds of the present invention in the calendering operation. It is sufficient to say that the compositions utilized in the process of the present invention are useful throughout the calendering industry. The calendering operation is initiated by mixing the polyvinyl chloride resin with the organo-tin stabilizer and the partial ester in the required amounts and thereafter thoroughly mixing such composition together and heating prior to delivery to the calendering roll.
The following are examples of the present invention.
EXAMPLE I
A partial ester of pentaerythritol which is very useful as an internal lubricant and as a co-stabilizer in organo-tin stabilized polyvinyl chloride clear plastics is formed as follows.
A saturated fatty acid having the following acid chain length distribution is obtained.
Percent by Weight:
3 --C14 Fatty Acid
0.5 --C15 Fatty Acid
42.5 --C16 Fatty Acid
2 --C17 Fatty Acid
52 --C18 Fatty Acid
The fatty acid so obtained is reacted under vacuum (with prior nitrogen sparge) at 77.66 parts by weight thereof with 29.22 parts by weight of pentaerythritol. Tin oxide is used as a catalyst at 0.05 parts. The resulting ester, following a reaction time of about 4 hours at 190 degrees C., is a compound whch contains 30 percent monoester, 50 percent diester and 20 percent triester.
The partial ester has a melt point of 50-55 degrees C. The reaction is conducted such that the compound is substantially free of free fatty acids with an acceptable acid number of less than 2.5, in this case 0.9. The saponification number should be in the range of 160 to 180 and is in this example 177.5 with a hydroxyl number of 200. The composition is substantially free of any unreacted pentaerythritol. The tetraester is not found in significant amounts in the composition.
This Example may be varied by employing a substantially pure fatty acid mixture containing 55 parts 18 carbon acid and 45 parts 16 carbon acid.
EXAMPLE II
A fully formulated polyvinyl chloride composition is prepared as follows: 0.2 parts by weight of the partial pentaerythritol ester of Example I is blended together with 1.5 parts of dioctyltin diglycolate and 100 parts of polyvinyl chloride resin. The mixture is heated to a temperature of 200 degrees C. and subjected to a calendering operation. The calendering operation uses a 450×220 mm roll at 200 degrees C. at a pressure of 4.4 kilopunkts and a roll speed of 12.5 rpm's.
The composition prepared as above when tested shows a substantial viscosity reduction at less than 0.5 part of the partial ester in the polyvinyl chloride composition. A composition showing a comparison where the amount of stearyl stearate utilized as the lubricant in place of the partial ester requires 1.0 parts before an internal lubricating effect is obtained. One example shows a known internal lubricant to show an increase in flow resistance and not to meet the viscosity reduction even at levels of use seven times greater than that of the presently claimed internal lubricant. It is also noted that the compositions made with the partial esters are substantial more stable due to the ability of the unreacted hydroxyls on the ester to form an organic chloride and to liberate water. This is particularly beneficial in that tin salts are utilized for their low toxicity, however, tin salts when utilized as Hcl scavengers are not particularly effective and thus, the additional benefit of the partial ester is observed.
Substantially similar results are observed when substituting the various acid chain length mixtures and degrees of partial ester formation throughout the ranges previously described. | The present invention describes the manufacture of polyvinyl chloride compounds containing an organo-tin compound and a partial ester which functions both as an internal lubricant and as a co-stabilizer to scavenge hydrochloric acid thereby lessening thermal degradation of the product. | 2 |
PRIORITY CLAIM
[0001] This application is a continuation of co-pending International Application No. PCT/EP2014/050912 filed on Jan. 17, 2014, which designates the United States and claims priority from European Application No. 13151925.8 filed on Jan. 18, 2013 and European Application No. 13166084.7 filed on Apr. 30, 2013, each of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an automated handling system for applying balancing weights to rims of vehicle wheels.
[0004] 2. Description of Relevant Art
[0005] A device for the application of balancing weights to go vehicle wheels is disclosed in U.S. Pat. No. 8,336,379 B2. A program-controlled manipulator device includes a movable working arm having a balancing head. The balancing head feeds a continuous weight strand of self-adhesive weights and applies these to a rim of a wheel. The drawback is that the strand of weights may only be delivered to specific rims and to specific locations thereof. Furthermore, the delivered strand of weights may have an optical appearance, which is often not desired.
SUMMARY OF THE INVENTION
[0006] The embodiments are based on the object of providing a device and a method for applying individual balancing weights to rims of vehicle wheels. Such individual balancing weights preferably are pre-fabricated and have predetermined sizes and weights. Such balancing weights may also be made in various shapes and colors resulting in an aesthetic appearance.
[0007] In an embodiment, a balancing weight application head is attached to a program controlled manipulator device. The balancing weight application head may pick up at least one individual balancing weight which my may be provided by a balancing weight dispenser. While the manipulator device moves the application head to the vehicle wheel, the balancing weight is firmly held by the application head. After the application head has been brought to the desired location for placing the balancing weight, the balancing weight is attached to the rim. Thereafter, the balancing head may be returned to the dispenser for picking up the next balancing weight. The balancing weight application head may also hold a plurality of balancing weights, therefore reducing movement time by the manipulator device. There may be different embodiments of the application head. The application head preferably has at least one means for holding a balancing weight at the application head and at least one means for pressing the balancing weight to a rim of a vehicle wheel. Both functions may be performed by the same means.
[0008] A further embodiment relates to a method of applying balancing weights to the rim of the vehicle by using an application head.
[0009] Another embodiment relates to an intermediate carrier for attaching the balancing weights. First, the intermediate carrier, to which the balancing weights are attached, is located within the rim. Then the intermediate carrier is expanded until the balancing weights touch the rim and are firmly pressed to the rim. Then the intermediate carrier may be deflated.
[0010] A further embodiment relates to a method of applying balancing weights to the rim of the vehicle by using an intermediate carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings.
[0012] FIG. 1 shows a balancing weight and an application head of a first embodiment.
[0013] FIG. 2 shows the basic function of the holding pins.
[0014] FIG. 3 shows a further embodiment of an application head.
[0015] FIG. 4 shows another embodiment with a plurality of pressure pieces.
[0016] FIG. 5 shows a further embodiment with vacuum holder.
[0017] FIG. 6 shows another embodiment with vacuum holder.
[0018] FIG. 7 shows an embodiment with permanent magnet.
[0019] FIG. 8 shows an embodiment with solenoid.
[0020] FIG. 9 shows an embodiment with three holding pins.
[0021] FIG. 10 shows a clip-on balancing weight held by three holding pins.
[0022] FIG. 11 shows the embodiment of FIG. 10 in a top view.
[0023] FIG. 12 shows another embodiment of a balancing weight application device.
[0024] FIG. 13 shows an intermediate step for applying balancing weights.
[0025] FIG. 14 shows the final step for applying balancing weights.
[0026] FIG. 15 shows an embodiment of an application tool for balancing weights.
[0027] FIG. 16 shows the first step of attaching the balancing weight.
[0028] FIG. 17 shows the next step of attaching a balancing weight.
[0029] FIG. 18 shows the attached balancing weight.
[0030] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] In FIG. 1 , a first embodiment is shown. A first balancing weight 10 has a center section 11 and at least one side section 12 , 13 . The center section 11 has at least one hole 14 , 15 . Preferably, there are two holes. Whereas the center section 11 preferably has a standard size and a standard location of the at least one hole 14 , 15 , the sections 12 , 13 may vary in size with the weight of the balancing weight. There may be further side sections besides of the side sections 12 and 13 , which is specifically useful for heavy balancing weights. Low weight balancing weights may have a slightly extended center section without side sections. The balancing weight has an attachment surface for attachment to the rim of a vehicle wheel, which preferably bears an adhesive tape 16 , also called self-adhesive tape. In this figure, the adhesive tape is shown partially removed to show the holes 14 , 15 . It is preferred, if the adhesive tape covers all the attachment surface, and therefore covers the holes. The application head 20 has a base 21 having at least one holding pin 22 , 23 . The holding pins 22 , 23 preferably may penetrate into the holes 14 , 15 . Furthermore it is preferred, if at least one pressure lever 24 , 25 is provided for pressing the balancing weight against the mounting surface 91 of rim 90 . The holding pins 22 , 23 fit into the holes 14 , 15 of the balancing weights and allow holding of the balancing weight at the application head during transport of the balancing weight from the dispenser to the rim. Preferably, at least one of the holding pins 22 , 23 is movable to generate some retention force within the holes 14 , 15 to clamp the balancing weight. In the embodiment shown, the holding pin 22 is fixed, while the holding pin 23 is movable. In another embodiment, at least one of the holding pins may have a conical shape or any other shape suitable for a form fit or press fit with at least one of the holes. In a further embodiment, at least one of the holding pins 22 , 23 has such a length to contact the adhesive tape at the attachment surface through at least one of the holes to further increase the holding force of the balancing weight to the pin. The at least one pressure lever 24 , 25 is provided for generating pressure to the whole surface of the balancing weight 10 and therefore to the whole area of the adhesive tape 16 . To adapt the pressure lever 24 , 25 to various rim diameters, it is preferred, if the pressure lever may be adjusted or moved. Such a preferred direction of movement is shown by the arrows 26 and 27 . Instead of pressure levers, any other device performing a similar function may be used.
[0032] In FIG. 2 , the basic function of the holding pins is shown. There is a first holding pin 22 may be fixed to the base 21 of the application head, the second holding pin 23 may be movable, slidable or tiltable and preferably is spring-loaded by a spring 28 against the base 21 . Due to the spring loading, the application head may simply be pressed against the balancing weight in the dispenser. The holding pins will slide into the holes and the spring 28 will assert enough force to press the holding pins against the walls of the holes and to hold the balancing weight at the application head. After the balancing weight has been pressed to the rim, the adhesive tape holds the balancing weight thereon. Now, the application head may simply be pulled off and the holding pins will slide out of the holes. Furthermore, it is preferred, if the holding pins each have a head 29 , which improves holding of the balancing weight at the application head. Each head 29 may have a rounded shape to simplify insertion of the holding pin into the holder of the balancing weight. Preferably, the holding pins have a conical shape. Most preferably, they may be pressed into corresponding holes of the balancing weights, establishing a relatively tight fit. Furthermore, there may be some structure for increasing friction and improving the holding function.
[0033] In FIG. 3 , another embodiment of an application head 40 is shown. This application head is suitable for handling balancing weights without holes. Such balancing weights preferably have a plurality of segments. These segments may have the same weight and size or they may be different. Here, the balancing weights are clamped between an edge or sidewall 41 , which may be part of the base 21 , and which may improve alignment of the balancing weight, and a pressure piece 42 . This pressure piece preferably may have at chamfered edge 43 , which allows simple insertion of the balancing weights. The pressure piece 42 may be held by a lever element 44 , which may be moved into the direction indicated by arrow 45 to increase the gap between the pressure of peace 42 and the edge 41 to fit balancing weights in-between. Preferably, the pressure piece and/or the lever element may be spring-loaded. Either there may be a separate spring or the lever element itself may act as a spring. The pressure piece 42 may be varied in its width. In a first embodiment it may be as shown, therefore clamping only one or two segments of the balancing weight. In another embodiment, the pressure piece may be broader to clamp a plurality of segments or even the whole balancing weight. Instead, by using a pressure piece, the balancing weight may be held by using the adhesive surface, or an edge thereof.
[0034] In FIG. 4 , a further modification of the embodiment of FIG. 3 is shown. Here a plurality of pressure pieces 42 , preferably having individual lever elements 44 are provided. As each lever element will be adjustable to the width of the balancing weight section it is holding, a constant holding force may be applied by each pressure piece independent of mechanical tolerances of the balancing weight. Therefore, this embodiment results in a better holding of balancing weights.
[0035] In FIG. 5 , another embodiment of an application head 50 having a vacuum holder is shown. Preferably, the application had has an empty inner space and or air duct which may be connected to at least one vacuum pipe which may be connected to a vacuum pump. Due to the vacuum of the application head, the balancing weights are held thereto. The vacuum may be switched on and off for holding and for releasing the balancing weigh. Alternatively, there may be a continuous vacuum, if the retention force of the adhesive tape is higher than the vacuum force. It is preferred, if there is a porous surface 51 for distributing the vacuum over the surface of the application head 51 . Such a process surface may be a fibrous web or a porous sintered material. It is preferred, if the balancing weights do not have holes, as this may lead to loss of vacuum.
[0036] In FIG. 6 , a further embodiment of an application head the 50 is shown. Here a plurality of suction cups 53 is provided to hold the balancing weights 30 .
[0037] Another embodiment of an application head 60 having at least one permanent magnet 61 is shown in FIG. 7 . Here, the balancing weights 30 are held by magnetic force. Preferably, the magnetic force is less than the retention force of the balancing weights held by the adhesive tape to the rim. The balancing weights 30 preferably comprise magnetic material. This magnetic material may be part of the body of the balancing weights or included therein. The magnetic material may also be at the outside of the balancing weights and may be part of coating or painting of the balancing weights.
[0038] A further embodiment according to FIG. 8 comprises a solenoid. This may be combined with a permanent magnet. Preferably, a solenoid coil 62 is provided in the application head 60 . Electrical current is delivered by cables 63 . The magnetic force applied it to the balancing weights may be switched on or off by switching the electric current through the solenoid.
[0039] Another embodiment according to FIG. 9 includes a plurality of holding pins, preferably three or four pins. Most preferably, the application head has a pair of fixed pins 71 , 72 and one or two movable pins 73 . Preferably, the movable pin can be moved to words or away from the fixed pins to adapt the gap between the fixed pins and the movable pin to the size of a balancing weight. The balancing weight may be clamped in between the pins. It is preferred, if the movable pin is driven by an actuator, which may be a solenoid, a motor or a hydraulic or pneumatic drive. Is further preferred, if at least one fin, preferably or pins have a holding structure 76 , 77 for holding the balancing weight. Such a holding structure may comprise one or a plurality of at least one of notches, recesses, holes, structured surfaces causing higher friction. Preferably, a notch 76 may be provided for balancing weights, which are clipped to a rim, while a recessed structure 77 may be used to hold adhesive balancing weights. It is also within the scope of this invention to exchange the fixed and movable pins, therefore moving the fixed pins and fixing the movable pins.
[0040] FIG. 10 shows a clip-on balancing weight 80 held by two fixed pins 71 , 72 and a movable pin 73 .
[0041] FIG. 11 shows the same balancing weight 80 held by three pins in a top view.
[0042] FIG. 12 shows a further embodiment of a weight that balancing weight-mounting device. An intermediate carrier 100 is provided within the rim 90 . The outer diameter of the intermediate carrier is smaller than the in the diameter of the rim. The intermediate carrier 100 holds at least one or a plurality of balancing weights 20 . These may be any type of balancing weights, like the balancing weights shown herein, preferably adhesive balancing weights. The balancing weights may be attached to the intermediate carrier 100 by using an application head according to any one of the previous embodiments. The intermediate carrier may be some tire or balloon, which may be expanded by compressed air or liquid. It may also be expanded by using any pressure cylinder, which may be driven by at least one of spring forces, compressed air or liquids. Alternate drive means include a motor or solenoid.
[0043] FIG. 13 shows the next step in applying balancing weights. Here the intermediate carrier is expanded until it contacts the inner surface of the rim 90 . This will apply the balancing weights to the rim.
[0044] FIG. 14 shows the final step of applying the balancing weights. The intermediate carrier is fully expanded and preferably, uniform pressure indicated by pressure arrows 102 is applied to the surface of the rim, uniformly pressing the balancing weights to the rim. After that, the intermediate carrier may be deflated and removed from the rim.
[0045] FIG. 15 shows an embodiment of an application tool for balancing weights. The tool has an application head 120 comprising a balancing weight applicator 122 and a thrust plate 121 . The balancing weight applicator 122 has a surface as further described herein to hold balancing weights by any of the means described herein. Preferably, there are vacuum outlets 127 or vacuum pipes at the surface for holding balancing weights by vacuum. There may be an additional layer 19 on the surface of the applicator for evenly distributing vacuum and/or protecting the balancing weights. There may also be holding pins, clams, magnets or any other means for holding the balancing weights the balancing weight applicator 122 . An actuator 123 may be provided for actuating the application head. The actuator may be a hydraulic or pneumatic actuator, which may be supplied by pipes 124 . In an alternative embodiment, the actuator may be an electric actuator. In this case, there would be at least one supply cable 124 . In a further embodiment, the applicator may be operated manually. The application head 120 may also work without the actuator shown. For this purpose, it may for example be connected to an industrial robot. The thrust plate 121 and the applicator 122 are mounted slidable against each other, preferably into the direction of a main axis which is the actuators actuating axis. The thrust plate 121 preferably has two side wings which can be moved against two side wings of the balancing weight applicator 122 . When applying a balancing weight 10 to a rim, the balancing weight is placed at the applicator 122 and held by vacuum, magnetic force or any other means as described herein. Then, the applicator is brought into close proximity to the location of the rim, to which the balancing weights are to be applied. Preferably, the outer radius of the applicator is less than the inner radius of the rim. In this case, the balancing weight closest to the center of the applicator touches the rim first. Then, the thrust plate is further pressed into the direction of the rim. This causes the side wings of the thrust plate 125 to contact the side wings of the applicator 126 and to push them into the direction of the rim. This results in gradually pressing balancing weights starting from the center balancing weight outwards to the rim unto all balancing weights have been pressed to the rim. In this state, the radius of the applicator 126 is approximately equal to the radius of the rim. After all balancing weights have been pressed to the rim, the thrust plate is released, further releasing the applicator. To simplify handling movement, it is preferred, if there is a spring between the thrust plate and the applicator to hold the thrust plate and applicator in such a distance from each other, that the side wings of the thrust plate do not touch the applicator or at least put no significant force to the applicator or at least push the applicators side wings only so far, that the radius of the applicator remains smaller than the radius of the rim. When actuating the thrust plate 121 , the spring will be depressed allowing the thrust plate to assert force to the applicator. In another embodiment instead of a spring, the elasticity of the applicator's side wings is used. In this case, the elastic side wings of the applicator will push the thrust plate back when idle.
[0046] In FIG. 16 , a first step of the previous described method is shown. Here, the center balancing weight of three balancing weights 10 touches the rim 90 , whereas the other balancing weights are distant from the rim.
[0047] In FIG. 17 , a next step is shown. Here, the thrust plate 121 has further been moved into the direction 129 . The side wings of the thrust plate 121 assert pressure on the side wings of the applicator 122 , bending them towards the rim and pressing the balancing weights at the sides of the center balancing weight to the rim.
[0048] In FIG. 18 , the finally attached balancing weights are shown. For this step, the thrust plate 121 has still been moved further into the direction 129 . It now presses by its side wings the applicator's side wings in their full length to the balancing weights and the rim, causing the balancing weights to be pressed and to adhere to the rim.
[0049] The embodiments disclosed herein may be combined together. For example, an application head may have vacuum and magnetic holding means. Furthermore, any application head may have holding pins and/or pressure levers.
[0050] It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide a device for applying balancing weights to vehicle wheels. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.
LIST OF REFERENCE NUMERALS
[0051] 10 balancing weight
[0052] 11 center section
[0053] 12 , 13 first side section
[0054] 14 , 15 holes
[0055] 16 adhesive tape
[0056] 20 application head
[0057] 21 base
[0058] 22 , 23 holding pins
[0059] 24 , 25 pressure lever
[0060] 26 , 27 arrows indicating direction of movement
[0061] 28 spring
[0062] 29 holding pin head
[0063] 30 balancing weight
[0064] 40 application head
[0065] 41 edge
[0066] 42 pressure piece
[0067] 43 chamfered edge of pressure piece
[0068] 44 lever element
[0069] 45 arrow indicating direction of movement
[0070] 50 application head with first vacuum holder
[0071] 51 porous surface
[0072] 52 vacuum pipes
[0073] 53 suction cups
[0074] 60 application head containing a magnet
[0075] 61 permanent magnet
[0076] 62 solenoid
[0077] 63 cables
[0078] 70 application head with holding pins
[0079] 71 , 72 fixed pins
[0080] 73 movable pin
[0081] 74 arrow indicating direction of movement
[0082] 75 actuator
[0083] 76 , 77 holding structure
[0084] 80 clip-on balancing weight
[0085] 90 rim of a vehicle wheel
[0086] 91 mounting surface
[0087] 100 intermediate carrier
[0088] 101 direction of expansion
[0089] 102 direction of pressure
[0090] 120 application head
[0091] 121 thrust plate
[0092] 122 applicator
[0093] 123 actuator
[0094] 124 cables, pipes
[0095] 125 side wing of thrust plate
[0096] 126 side wing of applicator
[0097] 127 vacuum outlet | A device for the application of balancing weights to the rim of a vehicle wheel comprises a program controlled manipulator device with a balancing weight application head. The application head is configured to first pick up a balancing weight from a dispenser and then to be transported by the manipulator device to the rim, where the application head can apply the balancing weight to the rim. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 60/605,898, filed Aug. 31, 2004, which application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to internal combustion engine systems with multi-stage turbocharging systems, and the use of multi-stage turbines in general.
[0004] 2. Description of the Related Art
[0005] Turbocharging systems, such as for use with internal combustion engines, are well-known in the art. A turbocharger comprises an exhaust gas turbine coupled to a gas intake charge compressor. The turbine operates by receiving exhaust gas from an internal combustion engine and converting a portion of the energy in that exhaust gas stream into mechanical energy by passing the exhaust stream over blades of a turbine wheel, and thereby causing the turbine wheel to rotate. This rotational force is then utilized by a compressor, coupled by a shaft to the turbine wheel, to compress a quantity of air to a pressure higher than the surrounding atmosphere, which then provides an increased amount of air available to be drawn into the internal combustion engine cylinders during the engine's intake stroke. The additional compressed air (boost) taken into the cylinders can allow more fuel to be burned within the cylinder, and thereby offers the opportunity to increase the engine's power output.
[0006] In a turbocharged internal combustion engine system, the wide range of speed and power output levels at which the internal combustion engine may operate presents challenges for designing an appropriately matched turbocharging system with good mechanical efficiency for working with the engine. For example, while smaller turbochargers provide boost quickly and more efficiently at lower engine speeds, larger turbochargers provide boost more effectively at higher engine speeds. Because of the relatively narrow flow range over which a turbocharger operates efficiently, relative to the broader flow range generated by internal combustion engines, it is known in the prior art (e.g., in cases of high boost need), to provide a multi-stage turbocharging system, involving both a smaller (i.e. “high pressure”) turbocharger and a larger (i.e. “low pressure”) turbocharger, wherein the smaller high pressure turbocharger operates at lower engine speeds and the larger low pressure turbocharger takes over at higher engine speeds. It has been found valuable to switch between the two turbocharging stages through use of a bypass system to divert exhaust gas flow around the higher pressure turbocharger to the lower pressure turbocharger as needed.
[0007] As a result, bypassing exhaust flow around a turbine gas expander is also well-known in the art. Typically, turbine bypass systems are used in the prior art primarily to regulate system pressure across the higher stage turbine wheel, and can be operated by selectively bleeding off a portion of the upstream exhaust gas over a pressure drop through a bypass channel when backpressure caused by the turbine's operation causes the system pressure upstream of the turbine to exceed desired levels. Bleeding of the exhaust gas through the bypass channel is generally controlled by a small regulating valve (called a “wastegate”) in the exhaust piping channel around the turbine. A typical wastegate valve operates somewhat like a trap door, opening a port from the higher pressure turbine inlet to a lower pressure area by diverting a portion of the exhaust flow through a bypass channel around the turbine, with the bypassed exhaust flow naturally expanding over the pressure drop in the bypass channel and then reuniting with the remaining exhaust flow downstream of the bypassed turbine.
OBJECT OF THE INVENTION
[0008] An object of the present invention is to provide a more efficient multi-stage (i.e., with two or more stages) turbocharging system for internal combustion engine systems.
[0009] In furtherance of the object of this invention, it has been recognized that prior art wastegate and bypass mechanisms are a source of unnecessary loss of useful energy in prior art multi-stage turbocharging systems. Therefore, a further object of the present invention is to provide an efficient means for preserving, capturing, utilizing, and/or reducing the amount of energy otherwise lost in bypassing between stages in multi-stage turbocharging systems, in order to further improve the efficiency of internal combustion engine systems utilizing multi-stage turbocharging systems.
SUMMARY OF THE INVENTION
[0010] The present invention reduces the unrecovered loss of exhaust gas energy that otherwise occurs in bypassing exhaust flow from one stage to another in a conventional multi-stage turbocharging system. The preferred method of preserving such exhaust energy is through converting a portion of the exhaust energy of the bypassed flow from pressure to velocity by passing the bypassed flow, while substantially still at the higher exhaust energy level present upstream of the bypassed turbine, through a variable geometry valve/nozzle, turbine VGT vanes, or other reduced cross-sectional area nozzle, and then not allowing the accelerated flow to substantially lose that increased recoverable kinetic energy before reaching the subsequent stage's turbine wheel. This may be done, for example, through placing the variable geometry valve or VGT vane outlet adjacent to the lower pressure turbine wheel's blades (or sufficiently nearby such blades to avoid substantial dissipation of the increased acceleration/momentum effect), and at an appropriate incidence angle to the lower pressure turbine wheel's blades. The increased momentum resulting from accelerating the flow may then be imparted to the lower pressure turbine's wheel, and thereby allow converting the energy to a mechanical rotational force as is known in the art. Alternative means and preferred turbocharging hardware embodiments for efficiently preserving or capturing energy lost between stages in a multi-stage turbocharging system are also discussed. This system may be utilized between stages with internal combustion engine or other multi-stage turbine systems encompassing three or four (or more) stage systems as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale.
[0012] FIG. 1 is a schematic diagram of an internal combustion engine system with a prior art multi-stage turbocharging system.
[0013] FIG. 2 is a schematic diagram of an internal combustion engine system with a first turbocharging and bypass arrangement of the present invention.
[0014] FIG. 3 is a schematic diagram of an internal combustion engine system with a second, alternative bypass arrangement of the present invention.
[0015] FIG. 4 is a more detailed view of the turbocharging and bypass arrangement of the system shown in FIG. 3 .
[0016] FIG. 5 is a schematic diagram of an internal combustion engine system with another alternative turbocharging and bypass arrangement of the present invention.
[0017] FIG. 6A presents a preferred variable geometry valve/nozzle means for use with a two-volute low pressure turbine, with the valve/nozzle means being VGT vanes, shown in an open position, in a second volute of a two-volute low pressure turbine.
[0018] FIG. 6B provides another view of the FIG. 6A preferred variable geometry valve/nozzle means, but shown with the valve/nozzle means in a closed position.
[0019] FIG. 6C presents a conventional rotating VGT vane, for use in a turbine.
[0020] FIG. 6D presents an alternative VGT vane with an articulating trailing edge.
[0021] FIGS. 7A and 7B are sectional views of a two-volute turbine, showing an alternative variable geometry valve/nozzle means embodiment of the present invention for use in a second volute of a two-volute low pressure turbine.
[0022] FIG. 8 is a sectional view of a two-volute turbine, showing a second alternative variable geometry valve/nozzle means embodiment of the present invention for use in a second volute of a two-volute low pressure turbine.
[0023] FIG. 9A illustrates the preferred internal combustion engine multi-stage turbocharging and bypass arrangement of the present invention, with a partially cut-away view of volute 53 ′ in the invention.
[0024] FIG. 9B illustrates the two volute turbine of the preferred embodiment of an internal combustion engine multi-stage turbocharging and bypass arrangement of the present invention.
[0025] FIG. 10 presents a cut-away view of a two-volute turbine in a side-by-side orientation, such as for use in the preferred embodiment of FIGS. 9A and 9B of the invention.
[0026] FIG. 11 is a schematic view of another alternative embodiment of an internal combustion engine system of the present invention, with two turbines on a common shaft.
[0027] FIG. 12 is a more detailed view of the FIG. 11 two turbines on a common shaft turbocharging and bypass arrangement of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] FIG. 1 shows an internal combustion engine system with a multi-stage turbocharging and bypass system from the prior art. Referring to FIG. 1 , ambient air enters the system through intake line 11 . The intake air may optionally be mixed with recirculated exhaust gas (EGR) to form a charge-air mixture. The ambient air or EGR/ambient air mixture (“charge-air”) mixture flows through and is compressed by a first-stage low pressure air compressor 12 .
[0029] After compression in compressor 12 , the intake air may flow through a second-stage high pressure air compressor 16 for further compression. Alternatively, the intake air may be diverted at port 13 to optional bypass channel 14 and return to the intake line at port 17 , as regulated by the opening or closing of optional bypass valve 15 .
[0030] Intake air then enters the intake manifold 18 and into combustion chambers 20 of engine 19 through conventional valves (not shown) in a conventional manner. Following combustion in the combustion chambers 20 , the warm, pressurized exhaust gases leave the combustion chambers 20 , at a first, higher, exhaust gas energy level, through conventional valves (not shown) in a conventional manner, and flow from engine 19 through exhaust manifold 21 to exhaust line 28 .
[0031] After leaving the exhaust manifold 21 , exhaust gas in exhaust line 28 may flow through a high pressure turbine gas expander 25 . High pressure turbine gas expander 25 in exhaust line 28 is coupled to the high pressure air compressor 16 in the intake line 11 through shaft 29 ′, and together the combined expander and compressor device forms a high pressure turbocharger 30 . Alternatively to flowing through high pressure turbine 25 , a portion of the exhaust gas may be selectively diverted at port 22 to bypass channel 23 and return to the exhaust line at port 26 , as regulated by opening or closing of port 22 through operation of wastegate valve 24 , which is operated (actively or passively) to open in response to system pressure buildup upstream of turbine 25 . Wastegate valve 24 may be located anywhere within bypass channel 23 . It should be noted that even though the wastegated exhaust gas does not pass through turbine expander 25 , the pressure difference between the bypassed exhaust gas flow and the exhaust gas that has passed through turbine expander 25 is lost to natural expansion and dissipation of any increased velocity of the bypassed exhaust gas, either in bypass channel 23 or upon reuniting with the lower pressure exhaust flow in exhaust line 28 at port 26 .
[0032] Downstream of turbine gas expander 25 , the exhaust gas at this second, lower, exhaust gas energy level may then flow through low pressure turbine gas expander 27 for further expansion, and then exit the system through exhaust line 28 . It should also be noted for FIG. 1 that turbine gas expander 27 in exhaust line 28 is coupled to low pressure air compressor 12 in intake line 11 through shaft 29 , and together the expander 27 and compressor 12 integrated device form a low pressure turbocharger 31 .
[0033] FIG. 2 presents a first improvement on the prior art multi-stage turbocharged internal combustion engine system of FIG. 1 , as one embodiment operating in accordance with principles of the present invention. For ease of discussion in highlighting aspects of this embodiment of the invention over the prior art, the embodiment of FIG. 2 is presented herein as identical to FIG. 1 of the prior art in all respects (i.e., with identical components, numeration, system configuration and operation), except as hereafter described.
[0034] Referring to FIG. 2 in comparison to the FIG. 1 prior art, it will be noted that certain changes from the prior art have been made with relation to the bypass system around high pressure turbine 25 . Like valve 24 of FIG. 1 , valve 34 of FIG. 2 regulates (e.g. through a pressure differential) the quantity of exhaust gas diverted from exhaust line 28 through bypass means channel 33 to port 36 . However, in FIG. 2 , valve 34 and return port 36 are geometrically configured closer to, and at a more complementary angle for direction of the bypass flow toward the inlet of turbine 27 .
[0035] These changes in FIG. 2 are made in recognition that a portion of the energy in the bypassed exhaust gas that is diverted through bypass channel 33 is converted from pressure to kinetic energy (velocity) at valve 34 by passing the bypassed flow through valve 34 , with valve 34 acting as a reduced cross-sectional area nozzle. Valve/nozzle 34 therefore acts in FIG. 2 as a nozzle when in an open position, by providing a reduced cross-sectional area flow path for the bypassed exhaust gas. As an example, valve/nozzle 34 may open to form a flow path in the shape of a short tube with a taper or constriction (reduced cross-section) designed to speed up (and preferably also direct) the flow of exhaust gas. As will be known in the art, there are many known alternative structures that may also perform this similar “nozzle” function of speeding up the flow of a gas or fluid, which are also intended to be encompassed within this patent's use of the terms “nozzle” or “nozzle means” herein.
[0036] The accelerated flow exiting valve/nozzle 34 is there reunited at intersection point 36 with the flow in exhaust line 28 (or directly at an inlet to turbine 27 ), preferably in an orientation resulting in an optimal combined direction for the exhaust flows just prior to, and at an appropriate incidence angle to, the turbine wheel blades of turbine 27 , as will be known in the art. The accelerated flow is there converted, combined with the exhaust flow in exhaust line 28 , to a mechanical rotational force by turbine 27 . By locating port 36 sufficiently near the turbine wheel blades of turbine 27 , the accelerated flow is not allowed to substantially dissipate energy before reaching the turbine wheel of turbine 27 for work extraction. Regarding selection of acceptable distances between valve/nozzle 34 and the turbine wheel, it will be understood that the closer the distance will result in greater recovery of energy, and that through experimentation the distance can be increased until such point that the increase in recovery of energy from the bypass acceleration is no longer measurable with normal state of the art sensors and thus would no longer fall within the scope of this invention.
[0037] Thus, in FIG. 2 , bypass means 33 and valve/nozzle 34 provide bypassing of pressurized exhaust gas from the engine around the high pressure turbine to an inlet of the lower pressure stage turbine in this embodiment, by leaving the bypassed flow in a complementary flowing direction with the main exhaust flow just prior to the turbine wheel blades of turbine 27 , regardless of (and thus it is irrelevant for this particular embodiment) whether port 36 lies as a direct inlet to turbine 27 or as a substantially equivalent return port to exhaust line 28 just prior to turbine 27 .
[0038] FIG. 3 presents the same embodiment as FIG. 2 , but illustrating that the length of the bypass route 33 is irrelevant and may be substantially eliminated, if desired. In addition, for either FIG. 2 or 3 , the bypass route may optionally begin directly from exhaust manifold 21 instead of exhaust line 28 , if desired, such as is illustrated in FIG. 5 (discussed below).
[0039] FIG. 4 illustrates in more detail one embodiment of reuniting of the accelerated bypass flow with the main exhaust flow prior to and at an appropriate incidence angle to the turbine wheel blades of turbine 27 as discussed for FIGS. 2 and 3 above. As shown in FIG. 4 , bypass exhaust flow 49 in bypass route 33 passes through valve 34 in a reduced cross section (nozzle) area of bypass route 33 and/or port 36 , which produces an accelerated bypass exhaust flow 51 . Other “nozzle means” for accelerating the bypass exhaust flow may alternatively be used, as is known in the art. Accelerated bypass exhaust flow 51 then combines with the lower velocity main exhaust flow 50 in exhaust line 28 (or, alternatively, within the turbine 27 itself), forming combined exhaust flow 52 . Combined exhaust flow 52 preferably shortly thereafter hits the turbine blades 48 at a desired angle to cause turbine wheel 47 to spin, as is known in the art. Note, however, that it is not necessary for the bypass flow to reunite with the main exhaust flow prior to impact with the lower pressure turbine's wheel blades for the energy to be recovered.
[0040] FIG. 5 presents an alternative embodiment, with bypass route 43 connected directly to exhaust manifold 21 , instead of to exhaust line 28 . In this manner, for each of these embodiments, it will be understood that bypass means 43 may be shortened to be no more than a direct fluid connection between exhaust manifold 21 and an inlet to low pressure turbine 27 . In addition, returning to FIG. 5 , in FIG. 5 a two-volute turbine 27 ′ (e.g. FIG. 10 ) replaces turbine 27 , with one volute 53 of turbine 27 ′ receiving lower velocity and energy exhaust from exhaust line 28 downstream of high pressure turbine 25 , and the other volute 53 ′ of turbine 27 ′ receiving the higher energy and velocity (accelerated) bypassed exhaust directly from exhaust manifold 21 (without being reunited with other exhaust gas prior to impact with the lower pressure turbine's wheel blades). Volutes 53 and 53 ′ of turbine 27 ′ need not be of the same size. Two-volute turbines such as turbine 27 ′ are known in the art, although more commonly with volutes of the same size, such as for use with divided exhaust manifolds. FIG. 10 presents a cut-away view of a sample two-volute turbine 27 ′. It will also be understood that the flows from the two volutes of turbine 27 ′ may be coordinated in various ways with regard to the targeting of the respective flows toward the blades of the turbine wheel, if desired.
[0041] For FIGS. 2 through 5 above, it has already been discussed that valve 34 in the bypass route may function in the present invention as both (i) a regulating valve to control bypass flow, and (ii) as a nozzle that converts a portion of the exhaust energy of the bypassed flow from pressure to kinetic energy (in the form of increased velocity of the bypassed exhaust flow). Given the wide range of exhaust flows generated in internal combustion engines that operate under wide ranges of engine speed and load conditions, it is preferable with the present invention to utilize a valve/nozzle means with variable geometry capability in accelerating the bypassed exhaust flow, to extend the system's benefits and effectiveness over a wider range of engine operation.
[0042] There are various structures that may be utilized to serve the functions of valve/nozzle means 34 with the preferred variable geometry capability. In FIGS. 6A and 6B , as a preferred embodiment for use with a two-volute turbine 27 ′ (or also for single volute turbine 56 of the two turbine arrangement in FIG. 12 , discussed below), VGT vanes 54 surrounding the turbine wheel 47 function as the valve/nozzle means. FIG. 6C presents a larger view of a conventional VGT vane 54 .
[0043] FIG. 6A illustrates the vanes 54 in an open orientation, allowing and guiding passage of bypassed exhaust flow 49 to the turbine blades 48 , and additionally acting as variable geometry nozzles in accelerating the exhaust flow 49 into the turbine blades 48 . In contrast, FIG. 6B shows the vanes 54 of FIG. 6A in a completely closed orientation (i.e. here, lined up “tail to nose” around the turbine wheel 47 ), thereby sealing and blocking any bypass exhaust flow through the volute 53 ′ to the turbine blades 48 . In this manner, the position of the VGT vanes 54 can operate fully as a regulating valve to open or shut off flow, and dictates the back pressure applied to the exhaust line 28 and/or exhaust manifold 21 in the system, and thus also controls the pressure drop allowed for the main exhaust flow through the high pressure turbine 25 . This consequently provides flow control through the alternative exhaust paths, including proportional flow control, to extend the system's benefits and effectiveness over a wider range of engine speed and load operating conditions.
[0044] As an alternative to VGT vanes 54 for two-volute turbine 27 ′, FIGS. 7A and 7B utilize a sliding plate mechanism 54 ′ in volute 53 ′ to perform the valve/nozzle function in regulating and accelerating the bypass flow in volute 53 ′ to turbine blades 48 . Likewise, FIG. 8 utilizes a sliding member/mechanism 54 ″, as shown for a two-volute double flow turbine housing (wherein for this second example the two volutes are concentrically disposed with respect to the circumference of the turbine wheel 47 , as opposed to being side-by-side with respect to the circumference of the turbine wheel 47 ).
[0045] FIGS. 9A and 9B now present the preferred embodiment of the multi-stage turbocharging system of the present invention. FIG. 9A is similar to the embodiment of FIG. 5 , except as noted below. In the FIG. 9A preferred embodiment, valve/nozzle 34 is replaced by Variable Geometry Turbine (VGT) mechanism 54 in one volute, volute 53 ′, of two-volute turbine 27 ′. The two volutes 53 and 53 ′ are configured in a side-by-side orientation to each other with respect to their orientation around the circumference of the turbine wheel 47 , as shown by the partial cut-away view in FIG. 9A , and as also more clearly shown in FIG. 9B and in FIG. 10 . VGT mechanism 54 is presented herein in FIGS. 9A and 9B as conventional rotating adjustable vanes 54 (as also shown in FIGS. 6A-6C ), but it will be understood that other VGT and/or other nozzle mechanisms may also be equivalently employed (e.g. a sliding nozzle mechanism as used by Cummins or in FIGS. 7A-7B and 8 , or a vane with an articulating trailing edge ( FIG. 6D ), as a few examples) without departing from the scope of the invention.
[0046] As is known in the art, adjustable VGT vanes 54 act as nozzles to throttle exhaust gas and use the resulting restriction to create an accelerated, high velocity exhaust gas stream, and also to guide and direct that exhaust gas stream into the turbine wheel blades 48 (e.g., as is represented in FIG. 6A ). Thus, in one embodiment, VGT mechanism 54 comprises conventional VGT vanes, which are rotating vanes arranged in a circle in the turbine volute 53 ′, with the vanes able to rotate uniformly to form wider or narrower paths for the exhaust gas to the turbine blades 48 . VGT mechanism(s) 54 are preferably placed closely adjacent the turbine blades 48 such that the kinetic energy of the bypassed exhaust flow passing by such vanes is fully preserved and not lost prior to the bypassed exhaust flow hitting turbine blades 48 at the optimal angle, as will be understood in the art. In contrast, second volute 53 of turbine 27 ′ is preferably a fixed volute without a VGT mechanism 54 , but may optionally use VGT as well, if desired. The flow from both volutes 53 and 53 ′ target portion(s) of the turbine wheel blades 48 as desired, as for example shown in the sample embodiment of FIG. 9B .
[0047] Further referring to FIG. 9A , high pressure turbine 25 (presented simply in block form) is fluidly connected to exhaust manifold 21 by exhaust line 28 . High pressure turbine 25 may optionally contain a VGT mechanism, if desired. Exhaust gas enters and leaves high pressure turbine 25 through an inlet and outlet in conventional manner (not shown), to continue in exhaust line 28 to volute 53 of low pressure turbine 27 ′, where it is further expanded. The further expanded exhaust gas then leaves low pressure turbine 27 ′ through an outlet in conventional manner (not shown), to continue in exhaust line 28 for exhaust gas recirculation or for release from the exhaust system. Bypass means/turbine inlet 43 of low pressure turbine 27 ′ is also fluidly connected to exhaust manifold 21 , allowing high pressure exhaust gas to bypass high pressure turbine 25 to volute 53 ′ of low pressure turbine 27 ′. VGT mechanism 54 , as discussed above, here shown as adjustable rotating VGT vanes as one embodiment, acts in volute 53 ′ in place of a valve to regulate flow of bypassed exhaust gas flow 49 through volute 53 ′, and also acts as a nozzle means to convert the exhaust energy in bypassed exhaust flow 49 to kinetic energy (velocity) to create accelerated bypass exhaust flow 51 , and to guide or direct the accelerated bypass exhaust flow 51 to hit turbine blades 48 at an appropriate incidence angle (e.g., as shown in FIG. 6A ) for spinning of turbine wheel 47 . The placement of the VGT mechanism 54 near the turbine blades 48 allows the kinetic energy and increase in momentum of the bypassed exhaust flow to be preserved (by not allowing deceleration and expansion) for conversion to mechanical force at the turbine blades 48 . The expanded exhaust gas from volute 53 ′ then leaves low pressure turbine 27 ′ through an outlet in conventional manner (not shown), to continue in exhaust line 28 for exhaust gas recirculation or for release from the exhaust system, as discussed above.
[0048] FIG. 11 presents an alternative preferred embodiment of the engine system and turbocharging system of the present invention, similar to FIG. 5 and to FIGS. 9A and 9B , but comprising two low pressure turbines 56 and 57 on a common shaft 29 ″ instead of a two-volute low pressure turbine 27 ′. Turbine 56 utilizes a VGT mechanism 54 in a configuration and manner similar to volute 53 ′ from FIGS. 5 and 9 A- 9 B, and receives bypass exhaust flow from bypass route 43 in one of the manners as previously described above. Turbine 57 , on the other hand, preferably utilizes a fixed geometry, and receives exhaust gas from exhaust line 28 that has already passed through high pressure turbine 25 , as also previously described above. Each low pressure turbine 56 and 57 includes a separate turbine wheel arrangement (identified as turbine wheels 47 and 47 ′, and blades 48 and 48 ′, as shown in FIG. 12 ), with the rotating wheels 47 and 47 ′ connected by common rotating shaft 29 ″, which is also part of shaft 29 , which connects the two turbines 56 and 57 to compressor 12 (as shown in FIG. 11 ). The compressor 12 , shaft 29 and 29 ″, and two turbine arrangement 56 and 57 comprise turbocharger 31 ′ in this embodiment.
[0049] After expansion in turbines 56 and 57 of FIG. 9 , the exhaust gas flows that leave turbines 56 and 57 are thereafter combined downstream in exhaust line 28 (or within the two turbine turbocharger arrangement itself, in the alternative).
[0050] It will be understood from the foregoing that there are various other embodiments that could also be formed to achieve the novel objectives and methods of the inventions herein, and that such variations with equivalent functions and goals are also intended to fall within the scope of this patent. For example, the objectives of the inventions herein may apply to multi-stage turbines for gas or fluid flows in other applications than in conjunction with internal combustion engine turbocharging systems. This patent is therefore intended to be limited solely by the claims, in the manner allowed by law. | A more efficient multi-stage turbocharging system and method for internal combustion engine systems is set forth. The present invention recovers the loss of a portion of exhaust energy that conventionally occurs in bypassing exhaust flow from one stage to another in a multi-stage turbocharging system. The preferred method of preserving such exhaust energy is through converting a portion of the exhaust energy of the bypassed flow from pressure to kinetic energy (velocity) by passing the bypassed flow through a VGT vane outlet or other variable geometry valve/nozzle, and then not allowing the accelerated flow to dissipate energy before reaching the subsequent stage's turbine wheel, where the accelerated flow may then be converted to a mechanical rotational force by the lower pressure turbine's wheel. Preferred hardware for achieving the object of the invention is also set forth, including a preferred two-volute low pressure turbocharging system with a VGT mechanism in one turbine volute only, or an alternative low pressure turbocharger with two low pressure turbines on a common shaft (again, preferably, with a VGT mechanism in one turbine only). | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to controlling flow of exhaust gases from clothes dryers either outside of the home or into the home. In one of its aspects, the invention relates to a vent apparatus for controlling the flow of clothes dryer air into the dryer room. In another of its aspects, the invention relates to an apparatus for utilizing the heat and humidity from a clothes dryer in a home heating system.
2. State of the Prior Art
Clothes dryers used by many homes conventionally exhaust the heated dryer air outside the home. The air exhausted from the dryer is air which initially is taken from the dryer room at about 70° F. and is heated further by the dryer. Make-up air for the dryer room is drawn into the room from outside the building. The make-up air in the winter is much colder and drier than the 70° heated air which it replaces. Thus, the air must be heated and humidified to maintain the home at a given temperature. Under these circumstances, considerable energy in the form of heat and humidity must be added to the house when the clothes dryer is in operation.
The circulation of heated dryer air into the laundry room has been known for some time. This concept is disclosed in the U.S. Pat. No. 3,892,048 to Jacobson, (issued July 1, 1975), and U.S. Pat. No. 2,983,050 to Alaback (issued May 9, 1961). In Jacobson, a small dryer exhausts heated air to the front of the dryer through a screen. An exhaust pipe, blocked during delivery of the heated air to the front grill of the dryer is provided for venting the dryer air to the outside during warmer weather.
In Alaback, a portion of the exhaust air from the dryer can be diverted to a top portion of the dryer for room heating or clothes drying on a rack on top of the dryer. Although some adjustment is possible in Alaback, no complete recycle of the dryer air into the laundry room is possible without completely blocking the exhaust. Accordingly, some portion of the heated dryer air will always be ducted outside the room.
The use of exhaust air from a dryer for room heating is also disclosed in the U.S. Pat. No. 3,999,304 to Doty, (issued Dec. 28, 1976). In Doty, a portable filter box with multiple filters is connected directly to the dryer outlet.
The recycling of dryer air to a heat exchanger within a burner housing has been disclosed in the U.S. Pat. No. 3,969,070 to Thompson, (issued July 13, 1976). The use of heated dryer air for drying clothes in an external clothes bag is disclosed in the U.S. Pat. No. 3,197,886 to Brame et al, (issued Aug. 3, 1965).
The dryers having the recirculation outlets built into the dryer housings have experienced some problem with lint in the households, due to incomplete filtration, and condensation of moisture in and around the dryers. Thus, the dryers with the self-contained recirculating heat have not been especially successful to my knowledge.
The energy shortages and the higher prices of energy have rekindled interest in utilizing waste heat from dryers and avoiding the unnecessary energy consumption due to drawing cold air inside during the wintertime.
SUMMARY OF THE INVENTION
According to the invention, a vent assembly is provided for use in combination with a clothes dryer wherein the dryer has an outlet pipe extending therefrom for venting heated air outside the room. The vent assembly comprises a housing having an open front and a generally open interior, a conduit extending through the housing from an inlet opening in the housing to an outlet opening in the housing, means on the housing for coupling the dryer outlet pipe to the conduit at the outlet opening thereof and means on the housing coupling an exhaust pipe to the conduit at the outlet opening thereof for exhausting heated air from the room to the outside. A valve means is provided in the conduit for adjustably controlling the relative portions of heated air passing from the inlet opening to either of the interior of the housing or to the outlet. The valve means is adapted to substantially completely cut off the flow of heated air to the housing interior or alternatively to substantially completely cut off the flow of heated air to the outlet. A filter means is provided at the open front of the housing to completely cover the same. Means are provided for releasably retaining the filter means in the open front of the housing. Thus, with the invention, heated air from the dryer can be vented in whole or in part to the outside or to the inside of the room through the vent assembly.
The releasable retaining means desirably comprises a frame pivotably mounted at one side to one side of the housing and means for releasably securing the other side of the frame to the opposite side of the housing.
The valve means in a preferred embodiment comprises an opening in the conduit and a valve element movable from a first position covering the opening to a second position blocking flow through the conduit downstream of the conduit opening. The valve element is of a size and shape sufficient to cover the conduit opening when it is in the first position and to block the flow through the conduit when it is in the second position. Preferably, an actuator rod is pivotably connected at one end to the valve element and extends through the housing at another end so that the valve element is manually operable from outside the housing. The valve element desirably is pivotably mounted to the conduit at a point downstream of the conduit opening. In order to provide for adjustments of various proportions of the heated air to the room and to the outside, the actuator rod is frictionally held in the casing so that the valve element will stay in any given adjusted position.
Further, according to the invention, a room having a clothes dryer with a hot outlet connected to an exterior location through an exhaust conduit has a vent means coupled to the exhaust conduit for venting dryer air into the room. The vent means includes a housing separate from the dryer and having a generally hollow interior, an inlet opening and a vent opening in communication with the inlet opening. Filter means are provided in the housing between the inlet and vent openings for removal of lint. Means in at least one of the exhaust conduits and the vent means control the flow of dryer air adjustably between the exterior location and the vent means so that the relative proportion of dryer air to the vent means and the exterior location can be varied from substantially none to substantially all of the dryer air.
In one enbodiment, the exhaust conduit extends through the housing and the control means are provided in the housing. In another embodiment, the exhaust conduit is vented directly to the outside and the vent means is connected to the exhaust conduit through a branch conduit. In this embodiment, the control means is provided in the exhaust conduit and in the branch conduit. Further, the vent opening can be an open face in the housing. Alternatively, the vent opening can be a smaller conduit opening connected directly to a furnace air circulation system in order to circulate the heated air throughout the entire house. In this latter case, controls are preferably provided between the dryer and the drive motor for the circulating fan in order to circulate air through the air ducts when the dryer is operating. In this manner, condensation of moisture is prevented or minimized within the air circulating system.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a dryer vent according to the invention in relationship to a conventional dryer and ducting therefor;
FIG. 2 is a front view, partially broken away, of the dryer vent illustrated in FIG. 1;
FIG. 3 is a front view, partially broken away and similar to FIG. 2, of the dryer vent shown in FIG. 1 and illustrating the control lever in a deflecting position;
FIG. 4 is an enlarged detailed view of the connection between the control lever and the vent housing;
FIG. 5 is an exploded view of vent assembly according to the invention;
FIG. 6 is a schematic side elevational view of a modified form of the invention;
FIG. 7 is a schematic view of a second modified form of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and to FIG. 1 in particular, there is shown a dryer 12 of conventional design having a vent exhaust pipe 14 connected to an interior vent assembly 16. An exhaust pipe 18 leads from the interior vent assembly to an outside location through the wall by conventional means (not shown).
As seen in FIGS. 1 through 3 and 5, the vent assembly 16 comprises a housing 20 having a front door frame 22, pivotably mounted to the housing through a hinge 24 and suitable screw fasteners 26. A catch member 28 is provided on the housing opposite the hinge 24 through suitable screw fasteners 30 and a latch member 32, secured to the door frame 22 through screw fasteners 34, is provided in juxtaposition to the catch member 28 to securely fasten the door frame 22 in a closed position. The catch member 28 is a plastic member hinged at one end and having a hollow interior to receive the latch member 32. This latching mechanism is a conventional fastener which is commercially available.
An outlet fitting 36 of tapered construction is provided at the upper part of the housing 20 to receive the exhaust pipe 18 (FIG. 1). In similar manner, an inlet fitting 38 is provided at the bottom portion of the housing 20 to receive the vent exhaust pipe 14. The fittings 36 and 38 are conventional dryer pipe sections of for example 4" diameter, which are in common use in dryer exhaust systems.
A retaining flange 40 (FIG. 5) is provided around the interior of the housing just inside the front door frame 22. The retaining flange 40 is spaced from the front edge ofthe housing a distance approximately equal to the thickness of a standard fiberglass furnace filter. Thus, a furnace filter 42 is positioned in the housing at the front opening between the flange 40 and the front door frame 22. The furnace filter 42 is a standard furnace filter which conventionally has a rectangular rim which supports a central fiberglass batting.
The housing 20 has a generally hollow interior 44 and a conduit 46 extending from and communicating with the inlet fitting 38 and the outlet fitting 36. As illustrated in FIG. 2, air flow from the dryer can pass through the conduit 46 from the inlet fitting 38 to the outlet fitting 36.
An opening 48 is provided in the side of the conduit 46 adjacent to the hollow interior 44. A baffle deflector 50 is positioned within the conduit 46 and is hinged at 52 to the interior wall of the conduit 46 for rotational movement between a closed position blocking the opening 48 (illustrated in FIG. 2) and an open diverting position substantially blocking flow between the inlet fitting 38 and the outlet fitting 36 (FIG. 3). Thus, in the diverting position illustrated in FIG. 3, the flow of air through the conduit is diverted through the opening 48 and into the hollow interior 44 of the housing 20. The baffle deflector 50 thus, has a shape which covers the opening 48 when the baffle is in the closed position illustrated in FIG. 2 and is shaped to conform with the interior of the conduit 46 when the baffle is in the diverting position illustrated in FIG. 3. Preferably, the conduit 46 is square in cross-section and the baffle deflector 50 will therefore be rectangular in shape. Although a complete seal is typically not made by deflector 50, substantially all the heated air can be diverted into the open interior of the housing or directed through the conduit 46. A complete seal could, however, be made if desired.
An actuator rod 54 is pivotably mounted at pivot mounting 56 to the baffle deflector 50 and extends through the side of the housing 20 for exterior manual operation of the baffle deflector. As seen in FIG. 4, the side of the housing 20 has a rubber grommet 58 with a central opening in which the actuator rod 54 is slidably received. The rubber grommet 58 permits a relatively noiseless operation of the actuator rod and also permits some limited articulation of the actuator rod within the opening of the grommet as the rod moves between the diverting position and the close position while maintaining a tight seal between the opening in the housing 20 and the rod 54.
In operation of the form of the invention illustrated in FIGS. 1 through 5, the vent assembly 16 is connected to vent exhaust pipe 14 of the dryer 12. When the dryer operates, heated air from the dryer, containing moisture, will be exhausted from the dryer through the vent exhaust pipe 14 and will pass into the conduit 46. During warmer weather, when it is desirable to vent the heated dryer air to the outside, the actuator rod 54 is pushed inwardly as illustrated in FIG. 2 so that the heated air passes directly through the conduit 46 to the outside of the room. In colder weather, where it is desirable to vent the dryer air to the inside, the actuator rod 54 is pulled outwardly as illustrated in FIG. 3 so that the baffle deflector 50 assumes the deflecting position shown in FIG. 3. In this position, the heated air will be deflected into the interior of the housing 20 and will pass through the filter 42 into the room.
It will be noted that the deflector 50 is infinitely movable between the closed position of FIG. 2 and the deflecting position of FIG. 3 so that varying amounts of heated air can be deflected into the room. Thus, in moderate weather, it may be desirable to vent only part of the air into the room and an appropriate adjustment can be made with the actuator rod 54. The rubber grommet provides a tight connection between the rod 54 and the housing so that the rod will be held by the grommet in any adjusted position.
Reference is now made to FIG. 6 for a description of the second embodiment of the invention. In this embodiment, a dryer 12 has an outlet pipe 60 connected thereto for exhausting heated air from the dryer through a wall 76 and through a vent flap 62 to the outside of the building. A branch pipe 64 is connected to the outlet pipe 60 and a filter box housing 66, like housing 20, is connected to the upper end of the branch pipe 64. The filter box housing 66 has a hinged front door frame 68 which is like the door frame 22 in all respects. A standard furnace filter 70 is positioned at the front part of the housing 66 and behind the front door 68. A damper valve 72 is provided in the vent line 60 and a damper valve 74 is provided in the branch line 64. These damper valves control the flow of heated air through the vent flap 62 or alternatively through the filter box housing 66. The damper valves 72 and 74 are conventional valves which are adjustable so that the proportion of heated air flowing into the filter box and through the vent flap is adjustable substantially between 0% and 100%.
Reference is now made to FIG. 7 for a description of the third embodiment of the invention. In this figure, like numerals have been used to designate like parts.
The dryer is connected to a vent pipe 60 having an adjustable valve 72 fo exhausting heated air through the wall 76 and through the vent flap 62. A branch pipe 64 is connected to the vent pipe 60 and has a damper valve 74 for controlling the relative proportion of heated air flowing through the branch pipe 64. A filter housing 78 having a standard fiberglass furnace filter 80 positioned therein is connected to the outlet of the branch pipe 64. The filter housing 78 is closed with the exception of the inlet connected to the branch pipe 64 and an outlet connected to an outlet pipe 82. A furnace 86 having a bonnet or air duct 84 is connected to the outlet pipe 82. The air duct is a part of the air duct which extends throughout the house. A fan 88 is driven by a motor 90 through drive belt 92 to circulate the air through the air duct and throughout the room or house in which the dryer is placed.
The motor 90 is connected to a controller 94 through a control line 96. The controller 94 is also connected to the dryer through a control line 98. The controller is adapted to switch the motor 90 into an operating mode when the dryer is running. In this manner, the air is circulating through the air duct 84 whenever heated air is vented through the branch pipe 64 and into the air duct 84. Thus, circulation of the air prevents condensation of moisture within the hot air ducting system.
The embodiment of FIG. 7 operates in substantially the same manner as the embodiment of FIG. 6. Heated air from the dryer can be vented to the outside completely by closing off valve 74 or alternatively can be vented completely through the branch line 64 by closing off the valve 72 and opening up the valve 74. Alternately, the valves 72 and 74 can be adjusted to give varying degrees of flow of the heated air through the vent pipe 60 and the branch pipe 64 as desired to maintain certain temperatures. The heated air passing through the branch pipe 64 will pass through the filter housing 78 and thereafter pass into the bonnet 84 of the furnace whereupon it will be circulated throughout the hot air duct system of the house. In this manner, humidity and heat are added to the hot air system in the house and such heat and humidity flow through the normal heating channels.
Whereas the invention has been described with reference to venting the heated dryer air into a room containing the dryer, it is within the scope of the invention to vent the heated air into a room other than the dryer room. When the dryer room is relatively small, the heated air can be conducted to an adjacent or remote room through conventional ducting.
Reasonable variation and modification are possible within the scope of the foregoing disclosure and drawing without departing from the spirit of the invention. | A vent apparatus for controlling the flow of heated exhaust air from a clothes dryer has a housing connected to the heated exhaust conduit and a filter within the housing for filtering the exhaust gases. Controls regulate the relative amounts of exhaust gases directed outside the dryer room and through the housing into the dryer room. In one embodiment, the heated dryer air is ducted through the housing and the control is a valve which directs the gas either into the housing or through the exhaust outlet of the housing. The invention channels moist, heated air into a house in desired proportions to conserve heat energy and to humidify the home in the winter. | 3 |
TECHNICAL FIELD OF INVENTION
[0001] The present invention relates to inhibitors of p38, a mammalian protein kinase is involved in cell proliferation, cell death and response to extracellular stimuli. The invention also relates to methods for producing these inhibitors. The invention also provides pharmaceutical compositions comprising the inhibitors of the invention and methods of utilizing those compositions in the treatment and prevention of various disorders.
BACKGROUND OF THE INVENTION
[0002] Protein kinases are involved in various cellular responses to extracellular signals. Recently, a family of mitogen-activated protein kinases (MAPK) has been discovered. Members of this family are Ser/Thr kinases that activate their substrates by phosphorylation [B. Stein et al., Ann. Rep. Med. Chem., 31, pp. 289-98 (1996)]. MAPKs are themselves activated by a variety of signals including growth factors, cytokines, UV radiation, and stress-inducing agents.
[0003] One particularly interesting MAPK is p38. p38, also known as cytokine suppressive anti-inflammatory drug binding protein (CSBP) and RK, is isolated from murine pre-B cells that are transfected with the lipopolysaccharide (LPS) receptor, CD14, and induced with LPS. p38 has since been isolated and sequenced, as has the cDNA encoding it in humans and mouse. Activation of p38 has been observed in cells stimulated by stress, such as treatment of lipopolysaccharides (LPS), UV, anisomycin, or osmotic shock, and by treatment with cytokines, such as IL-1 and TNF.
[0004] Inhibition of p38 kinase leads to a blockade in the production of both IL-1 and TNF. IL-1 and TNF stimulate the production of other proinflammatory cytokines such as IL-6 and IL-8 and have been implicated in acute and chronic inflammatory diseases and in post-menopausal osteoporosis [R. B. Kimble et al., Endocrinol., 136, pp. 3054-61 (1995)].
[0005] Based upon this finding it is believed that p38, along with other MAPKs, have a role in mediating cellular response to inflammatory stimuli, such as leukocyte accumulation, macrophage/monocyte activation, tissue resorption, fever, acute phase responses and neutrophilia. In addition, MAPKs, such as p38, have been implicated in cancer, thrombin-induced platelet aggregation, immunodeficiency disorders, autoimmune diseases, cell death, allergies, osteoporosis and neurodegenerative disorders. Inhibitors of p38 have been implicated in the area of pain management through inhibition of prostaglandin endoperoxide synthase-2 induction. Other diseases associated with Il-1, IL-6, IL-8 or TNF overproduction are set forth in WO 96/21654.
[0006] Others have already begun trying to develop drugs that specifically inhibit MAPKs. For example, PCT publication WO 95/31451 describes pyrazole compounds that inhibit MAPKs, and, in particular, p38. However, the efficacy of these inhibitors in vivo is still being investigated.
[0007] Accordingly, there is still a great need to develop other potent, p38-specific inhibitors that are useful in treating various conditions associated with p38 activation.
SUMMARY OF THE INVENTION
[0008] The present invention addresses this problem by providing compounds that demonstrate strong and specific inhibition of p38.
[0009] These compounds have the general formulae:
[0010] or pharmaceutically acceptable salts thereof, wherein each of Q 1 and Q 2 are independently selected from 5-6 membered aromatic carbocyclic or heterocyclic ring systems, or 8-10 membered bicyclic ring systems comprising aromatic carbocyclic rings, aromatic heterocyclic rings or a combination of an aromatic carbocyclic ring and an aromatic heterocyclic ring.
[0011] The rings that make up Q 1 are substituted with 1 to 4 substituents, each of which is independently selected from halo; C 1 -C 3 alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′ or CONR′ 2 ; O—(C 1 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′ or CONR′ 2 ; NR′ 2 ; OCF 3 ; CF 3 ; NO 2 ; CO 2 R′; CONR′; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; CN; N(R′)C(O)R 4 ; N(R′)C(O)OR 4 ; N(R′)C(O)C(O)R 4 ; N(R′)S(O 2 )R 4 ; N(R′)R 4 ; N(R 4 ) 2 ; OR 4 ; OC(O)R 4 ; OP(O) 3 H 2 ; or N═C—N(R′) 2 .
[0012] The rings that make up Q 2 are optionally substituted with up to 4 substituents, each of which is independently selected from halo; C 1 -C 3 straight or branched alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, S(O 2 )N(R′) 2 , N═C—N(R′) 2 , R 3 , or CONR′ 2 ; O—(C 1 -C 3 )-alkyl; O—(C 1 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, S(O 2 )N(R′) 2 , N═C—N(R′) 2 ; R 3 , or CONR′ 2 ; NR′ 2 ; OCF 3 ; CF 3 ; NO 2 ; CO 2 R′; CONR′; R 3 ; OR 3 ; NR 3 ; SR 3 ; C(O)R 3 ; C(O)N(R′)R 3 ; C(O)OR 3 ; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; N═C—N(R′) 2 ; or CN.
[0013] R′ is selected from hydrogen, (C 1 -C 3 )-alkyl; (C 2 -C 3 )-alkenyl or alkynyl; phenyl or phenyl substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl.
[0014] R 3 is selected from 5-6 membered aromatic carbocyclic or heterocyclic ring systems.
[0015] R 4 is (C 1 -C 4 )-alkyl optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 ; or a 5-6 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 .
[0016] X, if present, is selected from —S—, —O—, —S(O 2 )—, —S(O)—, —S(O 2 )—N(R 2 )—, —N(R 2 )—S(O 2 )—, —N(R 2 )—C(O)O—, —O—C(O)—N(R 2 ), —C(O)—, —C(O)O—, —O—C(O)—, —C(O)—N(R 2 )—, —N(R 2 )—C(O)—, —N(R 2 )—, —C(R 2 ) 2 —, or —C(OR 2 ) 2 —.
[0017] Each R is independently selected from hydrogen, —R 2 , —N(R 2 ) 2 , —OR 2 , SR 2 , —C(O)—N(R 2 ) 2 , —S(O 2 )—N(R 2 ) 2 , or —C(O)—OR 2 , wherein two adjacent R are optionally bound to one another and, together with each Y to which they are respectively bound, form a 4-8 membered carbocyclic or heterocyclic ring;
[0018] R 2 is selected from hydrogen, (C 1 -C 3 )-alkyl, or (C 1 -C 3 )-alkenyl; each optionally substituted with —N(R′) 2 , —OR′, SR′, —C(O)—N(R′) 2 , —S(O 2 )—N(R′) 2 , —C(O)—OR′, or R 3 .
[0019] Y is N or C;
[0020] Z, if present, is N, NH, or, if chemically feasible, O;
[0021] A, if present, is N or CR′;
[0022] n is 0 or 1;
[0023] R 1 is selected from hydrogen, (C 1 -C 3 )-alkyl, OH, or O—(C 1 -C 3 )-alkyl.
[0024] In another embodiment, the invention provides pharmaceutical compositions comprising the p38 inhibitors of this invention. These compositions may be utilized in methods for treating or preventing a variety of disorders, such as cancer, inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, infectious diseases, viral diseases and neurodegenerative diseases. These compositions are also useful in methods for preventing cell death and hyperplasia and therefore may be used to treat or prevent reperfusion/ischemia in stroke, heart attacks, and organ hypoxia. The compositions are also useful in methods for preventing thrombin-induced platelet aggregation. Each of these above-described methods is also part of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In order that the invention herein described may be more fully understood, the following detailed description is set forth. In the description, the following terms are employed:
[0026] The term “heterocyclyl” or “heterocycle” refers to a stable 3-7 membered monocyclic heterocyclic ring or 8-11 membered bicyclic heterocyclic ring which is either saturated or unsaturated, and which may be optionally benzofused if monocyclic. Each heterocycle consists of one or more carbon atoms and from one to four heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur. As used herein, the terms “nitrogen and sulfur heteroatoms” include any oxidized form of nitrogen and sulfur, and the quaternized form of any basic nitrogen. A heterocyclyl radical may be attached at any endocyclic carbon or heteroatom which results in the creation of a stable structure. Preferred heterocycles include 5-7 membered monocyclic heterocycles and 8-10 membered bicyclic heterocycles. Examples of such groups include imidazolyl, imidazolinoyl, imidazolidinyl, quinolyl, isoqinolyl, indolyl, indazolyl, indazolinolyl, perhydropyridazyl, pyridazyl, pyridyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, pyrazolyl, pyrazinyl, quinoxolyl, piperidinyl, pyranyl, pyrazolinyl, piperazinyl, pyrimidinyl, pyridazinyl, morpholinyl, thiamorpholinyl, furyl, thienyl, triazolyl, thiazolyl, carbolinyl, tetrazolyl, thiazolidinyl, benzofuranoyl, thiamorpholinyl sulfone, oxazolyl, benzoxazolyl, oxopiperidinyl, oxopyrrolidinyl, oxoazepinyl, azepinyl, isoxozolyl, isothiazolyl, furazanyl, tetrahydropyranyl, tetrahydrofuranyl, thiazolyl, thiadiazoyl, dioxolyl, dioxinyl, oxathiolyl, benzodioxolyl, dithiolyl, thiophenyl, tetrahydrothiophenyl, sulfolanyl, dioxanyl, dioxolanyl, tetahydrofurodihydrofuranyl, tetrahydropyranodihydrofuranyl, dihydropyranyl, tetradyrofurofuranyl and tetrahydropyranofuranyl.
[0027] The term “carbocyclyl” or “carbocycle” refers to a stable 3-7 membered monocyclic carbocyclic ring or 8-11 membered bicyclic carbocyclic ring which is either saturated or unsaturated, and which may be optionally benzofused if monocyclic.
[0028] The term “pharmaceutically acceptable salts” refers to compounds according to the invention used in the form of salts derived from inorganic or organic acids and bases.
[0029] Included among acid salts, for example, are the following: acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, flucoheptanoate, glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydrolodide, 2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, pamoate, pectianate, persulfate, phenylproprionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, tosylate and undecanoate.
[0030] Salts derived from appropriate bases include alkali metal (e.g. sodium), alkaline earth metal (e.g., magnesium), ammonium and NW 4 + (wherein W is C 1-4 alkyl) Physiologically acceptable salts of a hydrogen atom or an amino group include salts or organic carboxylic acids such as acetic, lactic, tartaric, malic, isethionic, lactobionic and succinic acids; organic sulfonic acids such as methanesulfonic, ethanesulfonic, benzenesulfonic and p-toluenesulfonic acids and inorganic acids such as hydrochloric, sulfuric, phosphoric and sulfamic acids. Physiologically acceptable salts of a compound with a hydroxy group include the anion of said compound in combination with a suitable cation such as Na + , NH 4 + , and NW 4 + (wherein W is a C 1-4 alkyl group).
[0031] Pharmaceutically acceptable salts include salts of organic carboxylic acids such as ascorbic, acetic, citric, lactic, tartaric, malic, maleic, isothionic, lactobionic, p-aminobenzoic and succinic acids; organic sulphonic acids such as methanesulphonic, ethanesulphonic, benzenesulphonic and p-toluenesulphonic acids and inorganic acids such as hydrochloric, sulphuric, phosphoric, sulphamic and pyrophosphoric acids.
[0032] For therapeutic use, salts of the compounds according to the invention will be pharmaceutically acceptable. However, salts of acids and bases that are not pharmaceutically acceptable may also find use, for example, in the preparation or purification of a pharmaceutically acceptable compound.
[0033] Preferred salts include salts formed from hydrochloric, sulfuric, acetic, succinic, citric and ascorbic acids.
[0034] The term “chemically feasible” refers to a connectivity of atoms such that the chemical valency of each atom is satisfied. For example, an oxygen atom with two bonds and a carbon atom with four bonds are chemically feasible.
[0035] The term “tautomerization” refers to the phenomenon wherein a proton of one atom of a molecule shifts to another atom. See, Jerry March, Advanced Organic Chemistry: Reactions, Mechanisms and Structures , Fourth Edition, John Wiley & Sons, pages 69-74 (1992). The term “tautomer” refers to the compounds produced by the proton shift.
[0036] The present invention provides inhibitors of p38 having the general formulae:
[0037] or pharmaceutically acceptable salts thereof, wherein each of Q 1 and Q 2 are independently selected from 5-6 membered aromatic carbocyclic or heterocyclic ring systems, or 8-10 membered bicyclic ring systems comprising aromatic carbocyclic rings, aromatic heterocyclic rings or a combination of an aromatic carbocyclic ring and an aromatic heterocyclic ring.
[0038] The rings that make up Q 1 are substituted with 1 to 4 substituents, each of which is independently selected from halo; C 1 -C 3 alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′ or CONR′ 2 ; O—(C 1 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′ or CONR′ 2 ; NR′ 2 ; OCF 3 ; CF 3 ; NO 2 ; CO 2 R′; CONR′; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; CN; N(R′)C(O)R 4 ; N(R′)C(O)OR 4 ; N(R′)C(O)C(O)R 4 ; N(R′)S(O 2 )R 4 ; N(R′)R 4 ; N(R 4 ) 2 ; OR 4 ; OC(O)R 4 ; OP(O) 3 H 2 ; or N═C—N(R′) 2 .
[0039] The rings that make up Q 2 are optionally substituted with up to 4 substituents, each of which is independently selected from halo; C 1 -C 3 straight or branched alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, S(O 2 )N(R′) 2 , N═C—N(R′) 2 , R 3 , or CONR′ 2 ; O—(C 1 -C 3 )-alkyl; O—(C 1 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, S(O 2 )N(R′) 2 , N═C—N(R′) 2 , R 3 , or CONR′ 2 ; NR′ 2 ; OCF 3 ; CF 3 ; NO 2 ; CO 2 R′; CONR′; R 3 ; OR 3 ; NR 3 ; SR 3 ; C(O)R 3 ; C(O)N(R′)R 3 ; C(O)OR 3 ; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; N═C—N(R′) 2 ; or CN.
[0040] R′ is selected from hydrogen, (C 1 -C 3 )-alkyl; (C 2 -C 3 )-alkenyl or alkynyl; phenyl or phenyl substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl.
[0041] R 3 is selected from 5-6 membered aromatic carbocyclic or heterocyclic ring systems.
[0042] R 4 is (C 1 -C 4 )-alkyl optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 ; or a 5-6 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 .
[0043] X, if present, is selected from —S—, —O—, —S(O 2 )—, —S(O)—, —S(O 2 )—N(R 2 )—, —N(R 2 ) —S(O 2 )—, —N(R 2 )—C(O)O—, —O—C(O)—N(R 2 ), —C(O)—, —C(O)O—, —O—C(O)—, —C(O)—N(R 2 )—, —N (R 2 )—C(O)—, —N(R 2 )—, —C(R 2 ) 2 —, or —C(OR 2 ) 2 —.
[0044] Each R is independently selected from hydrogen, —R 2 , —N(R 2 ) 2 , —OR 2 , SR 2 , —C(O)—N(R 2 ) 2 , —S(O 2 )—N(R 2 ) 2 , or —C(O)—OR 2 , wherein two adjacent R are optionally bound to one another and, together with each Y to which they are respectively bound, form a 4-8 membered carbocyclic or heterocyclic ring;
[0045] When the two R components form a ring together with the Y components to which they are respectively bound, it will obvious to those skilled in the art that a terminal hydrogen from each unfused R component will be lost. For example, if a ring structure is formed by binding those two R components together, one being —NH—CH 3 and the other being —CH 2 —CH 3 , one terminal hydrogen on each R component (indicated in bold) will be lost. Therefore, the resulting portion of the ring structure will have the formula —NH—CH 2 —CH 2 —CH 2 —.
[0046] R 2 is selected from hydrogen, (C 1 -C 3 )-alkyl, or (C 1 -C 3 )-alkenyl; each optionally substituted with —N(R′) 2 , —OR′, SR′, —C(O)—N(R′) 2 , —S(O 2 )—N(R′) 2 , —C(O)—OR′, or R 3 .
[0047] Y is N or C;
[0048] Z, if present, is N, NH or, if chemically feasible, O;
[0049] A, if present, is N or CR′;
[0050] n is 0 or 1;
[0051] R 1 is selected from hydrogen, (C 1 -C 3 )-alkyl, OH, or O—(C 1 -C 3 )-alkyl.
[0052] It will be apparent to one of skill in the art that the compounds of the present invention may exist as tautomers. Such tautomers may be transient or isolatable as a stable product. These tautomers are envisioned within the scope of the invention. For example, when R 1 is OH and Z is N in compounds IV and VI, tautomerization results in compounds of the formulae:
[0053] These compounds are also p38 inhibitors and fall within the scope of the present invention.
[0054] According to another preferred embodiment, Q 1 is selected from phenyl or pyridyl containing 1 to 3 substituents, wherein at least one of said substituents is in the ortho position and said substituents are independently selected from chloro, fluoro, bromo, —CH 3 , —OCH 3 , —OH, —CF 3 , —OCF 3 , —O(CH 2 ) 2 CH 3 , NH 2 , 3,4-methylenedioxy, —N(CH 3 ) 2 , —NH—S(O) 2 -phenyl, —NH—C(O)O—CH 2 -4-pyridine, —NH—C(O)CH 2 -morpholine, —NH—C(O)CH 2 —N(CH 3 ) 2 , —NH—C(O)CH 2 -piperazine, —NH—C(O)CH 2 -pyrrolidine, —NH—C(O)C(O)-morpholine, —NH—C(O)C(O)-piperazine, —NH—C(O)C(O)-pyrrolidine, —O—C(O)CH 2 —N(CH 3 ) 2 , or —O—(CH 2 ) 2 —N(CH 3 ) 2 .
[0055] Even more preferred are phenyl or pyridyl containing at least 2 of the above-indicated substituents both being in the ortho position.
[0056] Some specific examples of preferred Q 1 are:
[0057] Most preferably, Q 1 is selected from 2-fluoro-6-trifluoromethylphenyl; 2,6-difluorophenyl; 2,6-dichlorophenyl; 2-chloro-4-hydroxyphenyl; 2-chloro-4-aminophenyl; 2,6-dichloro-4-aminophenyl; 2,6-dichloro-3-aminophenyl; 2,6-dimethyl-4-hydroxyphenyl; 2-methoxy-3,5-dichloro-4-pyridyl; 2-chloro-4,5 methylenedioxy phenyl; or 2-chloro-4-(N-2-morpholino-acetamido)phenyl.
[0058] According to a preferred embodiment, Q 2 is phenyl or pyridyl containing 0 to 3 substituents, wherein each substituent is independently selected from chloro, fluoro, bromo, methyl, ethyl, isopropyl, —OCH 3 , —OH, —NH 2 , —CF 3 , —OCF 3 , —SCH 3 , —OCH 3 , —C(O)OH, —C(O)OCH 3 , —CH 2 NH 2 , —N(CH 3 ) 2 , —CH 2 -pyrrolidine and —CH 2 OH.
[0059] Some specific examples of preferred Q 2 are:
[0060] unsubstituted 2-pyridyl or unsubstituted phenyl.
[0061] Most preferred are compounds wherein Q 2 is selected from phenyl; 2-isopropylphenyl; 3,4-dimethylphenyl; 2-ethylphenyl; 3-fluorophenyl; 2-methylphenyl; 3-chloro-4-fluorophenyl; 3-chlorophenyl; 2-carbomethoxylphenyl; 2-carboxyphenyl; 2-methyl-4-chlorophenyl; 2-bromophenyl; 2-pyridyl; 2-methylenehydroxyphenyl; 4-fluorophenyl; 2-methyl-4-fluorophenyl; 2-chloro-4-fluorphenyl; 2,4-difluorophenyl; 2-hydroxy-4-fluorphenyl or 2-methylenehydroxy-4-fluorophenyl.
[0062] According to yet another preferred embodiment, X, if present, is —S—, —O—, —S (O 2 )—, —S(O)—, —NR—, —C(R 2 )— or —C(O)—. Most preferably, X is S.
[0063] According to another preferred embodiment, n is 1 and A is N.
[0064] According to another preferred embodiment, each Y is C.
[0065] According an even more preferred embodiment, each Y is C and the R attached to those Y components is selected from hydrogen or methyl.
[0066] A particularly preferred embodiment according to Formula I is
[0067] Particularly preferred embodiments according to Formula II include
[0068] A particularly preferred embodiment according to Formula III is
[0069] A particularly preferred embodiment according to Formula IV is
[0070] Particularly preferred embodiments according to Formula V include
[0071] Particularly preferred embodiments according to Formula VI include
[0072] A particularly preferred embodiment according to Formula VII is
[0073] According to another embodiment, the present invention provides methods of producing the above-identified inhibitors of p38 of the formulae I-VII. Representative synthesis schemes for formulae III, IV, V and VI are depicted below.
[0074] Schemes 1 and 2 outline the synthesis of compounds of types IV and VI, specifically where Z is nitrogen and A is a CH group. Both schemes start with a substituted anthranilonitrile derivative (a and a′). The synthesis of these types of derivatives is well known to those skilled in the art. In each case, the nitrile is reacted with an alkyl or aryl metallic compound, such as an alkyl or aryl lithium compound or a grignard reagent, to introduce the R1 substituent. This reaction is followed by in situ trapping of the reaction intermediates with dimethyl carbonate, or an equivalent reagent to form the cyclic compounds b and b′ (step 1). The NH of these compounds may then be alkylated utilizing various types of chemistries known to those skilled in the art to introduce the Q1 derivative (step 2). Alternatively, the amine of a or a′ may be alkylated or arylated prior to reaction of the nitrile with an organometallic compound (step 1). Yet another variation begins with an ortho halo nitrile which is reacted with an alkyl or aryl amine, utilizing one of a variety of chemistries known in the art to form a N-alkylated or arylated anthranilonitrile derivative a or a′.
[0075] Schemes 3 and 4 outline the synthesis of compounds of types III and V, specifically where Z is nitrogen and A is a CH group. Each synthesis starts with a substituted anthranilic amide (c or c′) compound. The preparation of this type of compound is well known to those skilled in the art. In step 1, the amine of c or c′ is alkylated or arylated utilizing one of many procedures known to those skilled in the art. Alternatively, an alpha halo benzoic amide derivative may be reacted with an alkyl or aryl amine utilizing one of a variety of procedures known in the art to form the N-alkylated or arylated c or c′ derivative. In step 2, the amide is reduced to form the diamine d or d′ using one of a variety of reducing reagents known to those skilled in the art. Step 3 then involves ring closure using phosgene, dimethyl carbonate or an equivalent reagent to form the desired compound of types III and V.
[0076] The activity of the p38 inhibitors of this invention may be assayed in vitro, in vivo or in a cell line. In vitro assays include assays that determine inhibition of either the kinase activity or ATPase activity of activated p38. Alternate in vitro assays quantitate the ability of the inhibitor to bind to p38 and may be measured either by radiolabelling the inhibitor prior to binding, isolating the inhibitor/p38 complex and determining the amount of radiolabel bound, or by running a competition experiment where new inhibitors are incubated with p38 bound to known radioligands.
[0077] Cell culture assays of the inhibitory effect of the compounds of this invention may determine the amounts of TNF, IL-1, IL-6 or IL-8 produced in whole blood or cell fractions thereof in cells treated with inhibitor as compared to cells treated with negative controls. Level of these cytokines may be determined through the use of commercially available ELISAs.
[0078] An in vivo assay useful for determining the inhibitory activity of the p38 inhibitors of this invention are the suppression of hind paw edema in rats with Mycobacterium butyricum -induced adjuvant arthritis. This is described in J. C. Boehm et al., J. Med. Chem., 39, pp. 3929-37 (1996), the disclosure of which is herein incorporated by reference. The p38 inhibitors of this invention may also be assayed in animal models of arthritis, bone resorption, endotoxin shock and immune function, as described in A. M. Badger et al., J. Pharmacol. Experimental Therapeutics, 279, pp. 1453-61 (1996), the disclosure of which is herein incorporated by reference.
[0079] The p38 inhibitors or pharmaceutical salts thereof may be formulated into pharmaceutical compositions for administration to animals or humans. These pharmaceutical compositions, which comprise and amount of p38 inhibitor effective to treat or prevent a p38-mediated condition and a pharmaceutically acceptable carrier, are another embodiment of the present invention.
[0080] The term “p38-mediated condition”, as used herein means any disease or other deleterious condition in which p38 is known to play a role. This includes conditions known to be caused by IL-1, TNF, IL-6 or IL-8 overproduction. Such conditions include, without limitation, inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, infectious diseases, neurodegenerative diseases, allergies, reperfusion/ischemia in stroke, heart attacks, angiogenic disorders, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, thrombin-induced platelet aggregation, and conditions associated with prostaglandin endoperoxidase synthase-2.
[0081] Inflammatory diseases which may be treated or prevented include, but are not limited to acute pancreatitis, chronic pancreatitis, asthma, allergies, and adult respiratory distress syndrome.
[0082] Autoimmune diseases which may be treated or prevented include, but are not limited to, glomerulonephritis, rheumatoid arthritis, systemic lupus erythematosus, scleroderma, chronic thyroiditis, Graves' disease, autoimmune gastritis, diabetes, autoimmune hemolytic anemia, autoimmune neutropenia, thrombocytopenia, atopic dermatitis, chronic active hepatitis, myasthenia gravis, multiple sclerosis, inflammatory bowel disease, ulcerative colitis, Crohn's disease, psoriasis, or graft vs. host disease.
[0083] Destructive bone disorders which may be treated or prevented include, but are not limited to, osteoporosis, osteoarthritis and multiple myeloma-related bone disorder.
[0084] Proliferative diseases which may be treated or prevented include, but are not limited to, acute myelogenous leukemia, chronic myelogenous leukemia, metastatic melanoma, Kaposi's sarcoma, and multiple myeloma.
[0085] Angiogenic disorders which may be treated or prevented include solid tumors, ocular neovasculization, infantile haemangiomas.
[0086] Infectious diseases which may be treated or prevented include, but are not limited to, sepsis, septic shock, and Shigellosis.
[0087] Viral diseases which may be treated or prevented include, but are not limited to, acute hepatitis infection (including hepatitis A, hepatitis B and hepatitis C), HIV infection and CMV retinitis.
[0088] Neurodegenerative diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, Alzheimer's disease, Parkinson's disease, cerebral ischemias or neurodegenerative disease caused by traumatic injury.
[0089] “p38-mediated conditions” also include ischemia/reperfusion in stroke, heart attacks, myocardial ischemia, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, and thrombin-induced platelet aggregation.
[0090] In addition, p38 inhibitors in this invention are also capable of inhibiting the expression of inducible pro-inflammatory proteins such as prostaglandin endoperoxide synthase-2 (PGHS-2), also referred to as cyclooxygenase-2 (COX-2). Therefore, other “p38-mediated conditions” are edema, analgesia, fever and pain, such as neuromuscular pain, headache, cancer pain, dental pain and arthritis pain.
[0091] The diseases that may be treated or prevented by the p38 inhibitors of this invention may also be conveniently grouped by the cytokine (IL-1, TNF, IL-6, IL-8) that is believed to be responsible for the disease.
[0092] Thus, an IL-1-mediated disease or condition includes rheumatoid arthritis, osteoarthritis, stroke, endotoxemia and/or toxic shock syndrome, inflammatory reaction induced by endotoxin, inflammatory bowel disease, tuberculosis, atherosclerosis, muscle degeneration, cachexia, psoriatic arthritis, Reiter's syndrome, gout, traumatic arthritis, rubella arthritis, acute synovitis, diabetes, pancreatic β-cell disease and Alzheimer's disease.
[0093] TNF-mediated disease or condition includes, rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis and other arthritic conditions, sepsis, septic shock, endotoxic shock, gram negative sepsis, toxic shock syndrome, adult respiratory distress syndrome, cerebral malaria, chronic pulmonary inflammatory disease, silicosis, pulmonary sarcoisosis, bone resorption diseases, reperfusion injury, graft vs. host reaction, allograft rejections, fever and myalgias due to infection, cachexia secondary to infection, AIDS, ARC or malignancy, keloid formation, scar tissue formation, Crohn's disease, ulcerative colitis or pyresis. TNF-mediated diseases also include viral infections, such as HIV, CMV, influenza and herpes; and veterinary viral infections, such as lentivirus infections, including, but not limited to equine infectious anemia virus, caprine arthritis virus, visna virus or maedi virus; or retrovirus infections, including feline immunodeficiency virus, bovine immunodeficiency virus, or canine immunodeficiency virus.
[0094] IL-8 mediated disease or condition includes diseases characterized by massive neutrophil infiltration, such as psoriasis, inflammatory bowel disease, asthma, cardiac and renal reperfusion injury, adult respiratory distress syndrome, thrombosis and glomerulonephritis.
[0095] In addition, the compounds of this invention may be used topically to treat or prevent conditions caused or exacerbated by IL-1 or TNF. Such conditions include inflamed joints, eczema, psoriasis, inflammatory skin conditions such as sunburn, inflammatory eye conditions such as conjunctivitis, pyresis, pain and other conditions associated with inflammation.
[0096] In addition to the compounds of this invention, pharmaceutically acceptable salts of the compounds of this invention may also be employed in compositions to treat or prevent the above-identified disorders.
[0097] Pharmaceutically acceptable salts of the compounds of this invention include those derived from pharmaceutically acceptable inorganic and organic acids and bases. Examples of suitable acid salts include acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptanoate, glycerophosphate, glycolate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oxalate, palmoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, salicylate, succinate, sulfate, tartrate, thiocyanate, tosylate and undecanoate. Other acids, such as oxalic, while not in themselves pharmaceutically acceptable, may be employed in the preparation of salts useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable acid addition salts. Salts derived from appropriate bases include alkali metal (e.g., sodium and potassium), alkaline earth metal (e.g., magnesium), ammonium and N—(C1-4 alkyl)4+ salts. This invention also envisions the quaternization of any basic nitrogen-containing groups of the compounds disclosed herein. Water or oil-soluble or dispersible products may be obtained by such quaternization.
[0098] Pharmaceutically acceptable carriers that may be used in these pharmaceutical compositions include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat.
[0099] The compositions of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir. The term “parenteral” as used herein includes subcutaneous, intravenous, intramuscular, intra-articular, intra-synovial, intrasternal, intrathecal, intrahepatic, intralesional and intracranial injection or infusion techniques. Preferably, the compositions are administered orally, intraperitoneally or intravenously.
[0100] Sterile injectable forms of the compositions of this invention may be aqueous or oleaginous suspension. These suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono- or di-glycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions may also contain a long-chain alcohol diluent or dispersant, such as carboxymethyl cellulose or similar dispersing agents which are commonly used in the formulation of pharmaceutically acceptable dosage forms including emulsions and suspensions. Other commonly used surfactants, such as Tweens, Spans and other emulsifying agents or bioavailability enhancers which are commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or other dosage forms may also be used for the purposes of formulation.
[0101] The pharmaceutical compositions of this invention may be orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, aqueous suspensions or solutions. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening, flavoring or coloring agents may also be added.
[0102] Alternatively, the pharmaceutical compositions of this invention may be administered in the form of suppositories for rectal administration. These can be prepared by mixing the agent with a suitable non-irritating excipient which is solid at room temperature but liquid at rectal temperature and therefore will melt in the rectum to release the drug. Such materials include cocoa butter, beeswax and polyethylene glycols.
[0103] The pharmaceutical compositions of this invention may also be administered topically, especially when the target of treatment includes areas or organs readily accessible by topical application, including diseases of the eye, the skin, or the lower intestinal tract. Suitable topical formulations are readily prepared for each of these areas or organs.
[0104] Topical application for the lower intestinal tract can be effected in a rectal suppository formulation (see above) or in a suitable enema formulation. Topically-transdermal patches may also be used.
[0105] For topical applications, the pharmaceutical compositions may be formulated in a suitable ointment containing the active component suspended or dissolved in one or more carriers. Carriers for topical administration of the compounds of this invention include, but are not limited to, mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene, polyoxypropylene compound, emulsifying wax and water. Alternatively, the pharmaceutical compositions can be formulated in a suitable lotion or cream containing the active components suspended or dissolved in one or more pharmaceutically acceptable carriers. Suitable carriers include, but are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water.
[0106] For ophthalmic use, the pharmaceutical compositions may be formulated as micronized suspensions in isotonic, pH adjusted sterile saline, or, preferably, as solutions in isotonic, pH adjusted sterile saline, either with or without a preservative such as benzylalkonium chloride. Alternatively, for ophthalmic uses, the pharmaceutical compositions may be formulated in an ointment such as petrolatum.
[0107] The pharmaceutical compositions of this invention may also be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and may be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other conventional solubilizing or dispersing agents.
[0108] The amount of p38 inhibitor that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated, the particular mode of administration. Preferably, the compositions should be formulated so that a dosage of between 0.01-100 mg/kg body weight/day of the inhibitor can be administered to a patient receiving these compositions.
[0109] It should also be understood that a specific dosage and treatment regimen for any particular patient will depend upon a variety of factors, including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, rate of excretion, drug combination, and the judgment of the treating physician and the severity of the particular disease being treated. The amount of inhibitor will also depend upon the particular compound in the composition.
[0110] According to another embodiment, the invention provides methods for treating or preventing a p38-mediated condition comprising the step of administering to a patient one of the above-described pharmaceutical compositions. The term “patient”, as used herein, means an animal, preferably a human.
[0111] Preferably, that method is used to treat or prevent a condition selected from inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, infectious diseases, degenerative diseases, allergies, reperfusion/ischemia in stroke, heart attacks, angiogenic disorders, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, and thrombin-induced platelet aggregation.
[0112] According to another embodiment, the inhibitors of this invention are used to treat or prevent an IL-1, IL-6, IL-8 or TNF-mediated disease or condition. Such conditions are described above.
[0113] Depending upon the particular p38-mediated condition to be treated or prevented, additional drugs, which are normally administered to treat or prevent that condition may be administered together with the inhibitors of this invention. For example, chemotherapeutic agents or other anti-proliferative agents may be combined with the p38 inhibitors of this invention to treat proliferative diseases.
[0114] Those additional agents may be administered separately, as part of a multiple dosage regimen, from the p38 inhibitor-containing composition. Alternatively, those agents may be part of a single dosage form, mixed together with the p38 inhibitor in a single composition.
[0115] In order that the invention described herein may be more fully understood, the following examples are set forth. It should be understood that these examples are for illustrative purposes only and are not to be construed as limiting this invention in any manner.
EXAMPLE 1
Cloning of p38 Kinase in Insect Cells
[0116] Two splice variants of human p38 kinase, CSBP1 and CSBP2, have been identified. Specific oligonucleotide primers were used to amplify the coding region of CSBP2 cDNA using a HeLa cell library (Stratagene) as a template. The polymerase chain reaction product was cloned into the pET-15b vector (Novagen). The baculovirus transfer vector, pVL-(His)6-p38 was constructed by subcloning a XbaI-BamHI fragment of pET15b-(His)6-p38 into the complementary sites in plasmid pVL1392 (Pharmingen).
[0117] The plasmid pVL-(His)6-p38 directed the synthesis of a recombinant protein consisting of a 23-residue peptide (MGSSHHHHHHSSGLVPRGSHMLE, where LVPRGS represents a thrombin cleavage site) fused in frame to the N-terminus of p38, as confirmed by DNA sequencing and by N-terminal sequencing of the expressed protein. Monolayer culture of Spodoptera frugiperda (Sf9) insect cells (ATCC) was maintained in TNM-FH medium (Gibco BRL) supplemented with 10% fetal bovine serum in a T-flask at 27° C. Sf9 cells in log phase were co-transfected with linear viral DNA of Autographa califonica nuclear polyhedrosis virus (Pharmingen) and transfer vector pVL-(His)6-p38 using Lipofectin (Invitrogen). The individual recombinant baculovirus clones were purified by plaque assay using 1% low melting agarose.
EXAMPLE 2
Expression and Purification of Recombinant p38 Kinase
[0118] [0118] Trichoplusia ni (Tn-368) High-Five™ cells (Invitrogen) were grown in suspension in Excel-405 protein free medium (JRH Bioscience) in a shaker flask at 27° C. Cells at a density of 1.5×10 6 cells/ml were infected with the recombinant baculovirus described above at a multiplicity of infection of 5. The expression level of recombinant p38 was monitored by immunoblotting using a rabbit anti-p38 antibody (Santa Cruz Biotechnology). The cell mass was harvested 72 hours after infection when the expression level of p38 reached its maximum.
[0119] Frozen cell paste from cells expressing the (His) 6 -tagged p38 was thawed in 5 volumes of Buffer A (50 mM NaH2PO4 pH 8.0, 200 mM NaCl, 2 mM β-Mercaptoethanol, 10% Glycerol and 0.2 mM PMSF). After mechanical disruption of the cells in a microfluidizer, the lysate was centrifuged at 30,000×g for 30 minutes. The supernatant was incubated batchwise for 3-5 hours at 4° C. with Talon™ (Clontech) metal affinity resin at a ratio of 1 ml of resin per 2-4 mgs of expected p38. The resin was settled by centrifugation at 500×g for 5 minutes and gently washed batchwise with Buffer A. The resin was slurried and poured into a column (approx. 2.6×5.0 cm) and washed with Buffer A+5 mM imidazole.
[0120] The (His) 6 -p38 was eluted with Buffer A+100 mM imidazole and subsequently dialyzed overnight at 4° C. against 2 liters of Buffer B, (50 mM HEPES, pH 7.5, 25 mM β-glycerophosphate, 5% glycerol, 2 mM DTT). The His 6 tag was removed by addition of at 1.5 units thrombin (Calbiochem) per mg of p38 and incubation at 20° C. for 2-3 hours. The thrombin was quenched by addition of 0.2 mM PMSF and then the entire sample was loaded onto a 2 ml benzamidine agarose (American International Chemical) column.
[0121] The flow through fraction was directly loaded onto a 2.6×5.0 cm Q-Sepharose (Pharmacia) column previously equilibrated in Buffer B+0.2 mM PMSF. The p38 was eluted with a 20 column volume linear gradient to 0.6M NaCl in Buffer B. The eluted protein peak was pooled and dialyzed overnight at 4° C. vs. Buffer C (50 mM HEPES pH 7.5, 5% glycerol, 50 mM NaCl, 2 mM DTT, 0.2 mM PMSF).
[0122] The dialyzed protein was concentrated in a Centriprep (Amicon) to 3-4 ml and applied to a 2.6×100 cm Sephacryl S-100HR (Pharmacia) column. The protein was eluted at a flow rate of 35 ml/hr. The main peak was pooled, adjusted to 20 mM DTT, concentrated to 10-80 mgs/ml and frozen in aliquots at −70° C. or used immediately.
EXAMPLE 3
Activation of p38
[0123] p38 was activated by combining 0.5 mg/ml p38 with 0.005 mg/ml DD-double mutant MKK6 in Buffer B+10 mM MgCl2, 2 mM ATP, 0.2 mM Na2VO4 for 30 minutes at 20° C. The activation mixture was then loaded onto a 1.0×10 cm MonoQ column (Pharmacia) and eluted with a linear 20 column volume gradient to 1.0 M NaCl in Buffer B. The activated p38 eluted after the ADP and ATP. The activated p38 peak was pooled and dialyzed against buffer B+0.2 mM Na2VO4 to remove the NaCl. The dialyzed protein was adjusted to 1.1M potassium phosphate by addition of a 4.0M stock solution and loaded onto a 1.0×10 cm HIC (Rainin Hydropore) column previously equilibrated in Buffer D (10% glycerol, 20 mM β-glycerophosphate, 2.0 mM DTT)+1.1 MK2HPO4. The protein was eluted with a 20 column volume linear gradient to Buffer D+50 mM K2HPO4. The double phosphorylated p38 eluted as the main peak and was pooled for dialysis against Buffer B+0.2 mM Na2VO4. The activated p38 was stored at −70° C.
EXAMPLE 4
P38 Inhibition Assays
[0124] A. Inhibition of Phosphorylation of EGF Receptor Peptide
[0125] This assay is carried out in the presence of 10 mM MgCl2, 25 mM β-glycerophosphate, 10% glycerol and 100 mM HEPES buffer at pH 7.6. For a typical IC50 determination, a stock solution is prepared containing all of the above components and activated p38 (5 nM). The stock solution is aliquotted into vials. A fixed volume of DMSO or inhibitor in DMSO (final concentration of DMSO in reaction is 5%) is introduced to each vial, mixed and incubated for 15 minutes at room temperature. EGF receptor peptide, KRELVEPLTPSGEAPNQALLR, a phosphoryl acceptor in p38-catalyzed kinase reaction, is added to each vial to a final concentration of 200 μM. The kinase reaction is initiated with ATP (100 μM) and the vials are incubated at 30° C. After 30 minutes, the reactions are quenched with equal volume of 10% trifluoroacetic acid (TFA).
[0126] The phosphorylated peptide is quantified by HPLC analysis. Separation of phosphorylated peptide from the unphosphorylated peptide is achieved on a reverse phase column (Deltapak, 5 μm, C18 100D, part no. 011795) with a binary gradient of water and acteonitrile, each containing 0.1% TFA. IC50 (concentration of inhibitor yielding 50% inhibition) is determined by plotting the % activity remaining against inhibitor concentration.
[0127] B. Inhibition of ATPase Activity
[0128] This assay is carried out in the presence of 10 mM MgCl2, 25 mM β-glycerophosphate, 10% glycerol and 100 mM HEPES buffer at pH 7.6. For a typical Ki determination, the Km for ATP in the ATPase activity of activated p38 reaction is determined in the absence of inhibitor and in the presence of two concentrations of inhibitor. Ki is determined from the rate data as a function of inhibitor and ATP concentrations. A stock solution is prepared containing all of the above components and activated p38 (60 nM). The stock solution is aliquotted into vials. A fixed volume of DMSO or inhibitor in DMSO (final concentration of DMSO in reaction is 2.5%) is introduced to each vial, mixed and incubated for 15 minutes at room temperature. The reaction is initiated by adding various concentrations of ATP and then incubated at 30° C. After 30 minutes, the reactions are quenched with 50 μl of EDTA (0.1 M, final concentration), pH 8.0. The product of p38 ATPase activity, ADP, is quantified by HPLC analysis.
[0129] Separation of ADP from ATP is achieved on a reversed phase column (Supelcosil, LC-18, 3 μm, part no. 5-8985) using a binary solvent gradient of following composition: Solvent A—0.1 M phosphate buffer containing 8 mM tetrabutylammonium hydrogen sulfate (Sigma Chemical Co., catalogue no. T-7158), Solvent B—Solvent A with 30% methanol.
[0130] C. Inhibition of IL-1, TNF, IL-6 and IL-8 Production in LPS-Stimulated PBMCs
[0131] Inhibitors are serially diluted in DMSO from a 20 mM stock. At least 6 serial dilutions are prepared. Then 4× inhibitor stocks are prepared by adding 4 μl of an inhibitor dilution to 1 ml of RPMI1640 medium/10% fetal bovine serum. The 4× inhibitor stocks contained inhibitor at concentrations of 80 μM, 32 μM, 12.8 μM, 5.12 μM, 2.048 μM, 0.819 μM, 0.328 μM, 0.131 μM, 0.052 μM, 0.021 μM etc. The 4× inhibitor stocks are pre-warmed at 37° C. until use.
[0132] Fresh human blood buffy cells are separated from other cells in a Vacutainer CPT from Becton & Dickinson (containing 4 ml blood and enough DPBS without Mg 2− /Ca 2+ to fill the tube) by centrifugation at 1500×g for 15 min. Peripheral blood mononuclear cells (PBMCs), which are located on top of the gradient in the Vacutainer, are removed and washed twice with RPMI1640 medium/10% fetal bovine serum. PBMCs are collected by centrifugation at 500×g for 10 min. The total cell number is determined using a Neubauer Cell Chamber and the cells are adjusted to a concentration of 4.8×10 6 cells/ml in cell culture medium (RPMI1640 supplemented with 10% fetal bovine serum).
[0133] Alternatively, whole blood containing an anti-coagulant is used directly in the assay.
[0134] 100 μl of cell suspension or whole blood is placed in each well of a 96-well cell culture plate. Then, 50 μl of the 4× inhibitor stock to the cells is added. Finally, 50 μl of a lipopolysaccharide (LPS) working stock solution (16 ng/ml in cell culture medium) is added to give a final concentration of 4 ng/ml LPS in the assay. The total assay volume of the vehicle control is also adjusted to 200 μl by adding 50 μl cell culture medium. The PBMC cells or whole blood are then incubated overnight (for 12-15 hours) at 37° C./5% CO2 in a humidified atmosphere.
[0135] The next day the cells are mixed on a shaker for 3-5 minutes before centrifugation at 500×g for 5 minutes. Cell culture supernatants are harvested and analyzed by ELISA for levels of IL-1b (R & D Systems, Quantikine kits, #DBL50), TNF-α (BioSource, #KHC3012), IL-6 (Endogen, #EH2-IL6) and IL-8 (Endogen, #EH2-IL8) according to the instructions of the manufacturer. The ELISA data are used to generate dose-response curves from which IC50 values are derived.
[0136] p38 inhibitors of this invention will inhibit phosphorylation of EGF receptor peptide, and the production of IL-1, TNF and IL-6, as well as IL-8 in LPS-stimulated PBMCs or in whole blood.
[0137] D. Inhibition of IL-6 and IL-8 Production in IL-1-Stimulated PBMCs
[0138] This assay is carried out on PBMCs exactly the same as above except that 50 μl of an IL-1b working stock solution (2 ng/ml in cell culture medium) is added to the assay instead of the (LPS) working stock solution.
[0139] Cell culture supernatants are harvested as described above and analyzed by ELISA for levels of IL-6 (Endogen, #EH2-IL6) and IL-8 (Endogen, #EH2-IL8) according to the instructions of the manufacturer. The ELISA data are used to generate dose-response curves from which IC50 values are derived.
[0140] E. Inhibition of LPS-Induced Prostaglandin Endoperoxide Synthase-2 (PGHS-2, or COX-2) Induction In PBMCs
[0141] Human peripheral mononuclear cells (PBMCs) are isolated from fresh human blood buffy coats by centrifugation in a Vacutainer CPT (Becton & Dickinson). 15×10 6 cells are seeded in a 6-well tissue culture dish containing RPMI 1640 supplemented with 10% fetal bovine serum, 50 U/ml penicillin, 50 μg/ml streptomycin, and 2 mM L-glutamine. An inhibitor of the instant invention is added at 0.2, 2.0 and 20 μM final concentrations in DMSO. Then, LPS is added at a final concentration of 4 ng/ml to induce enzyme expression. The final culture volume is 10 ml/well.
[0142] After overnight incubation at 37° C., 5% CO2, the cells are harvested by scraping and subsequent centrifugation, then the supernatant is removed, and the cells are washed twice in ice-cold DPBS (Dulbecco's phosphate buffered saline, BioWhittaker). The cells are lysed on ice for 10 min in 50 μl cold lysis buffer (20 mM Tris-HCl, pH 7.2, 150 mM NaCl, 1% Triton-X-100, 1% deoxycholic acid, 0.1% SDS, 1 mM EDTA, 2% aprotinin (Sigma), 10 μg/ml pepstatin, 10 μg/ml leupeptin, 2 mM PMSF, 1 mM benzamidine, 1 mM DTT) containing 1 μl Benzonase (DNAse from Merck). The protein concentration of each sample is determined using the BCA assay (Pierce) and bovine serum albumin as a standard. Then the protein concentration of each sample is adjusted to 1 mg/ml with cold lysis buffer. To 100 μl lysate an equal volume of 2×SDS PAGE loading buffer is added and the sample is boiled for 5 min. Proteins (30 μg/lane) are size-fractionated on 4-20% SDS PAGE gradient gels (Novex) and subsequently transferred onto nitrocellulose membrane by electrophoretic means for 2 hours at 100 mA in Towbin transfer buffer (25 mM Tris, 192 mM glycine) containing 20% methanol. The membrane is pretreated for 1 hour at room temperature with blocking buffer (5% non-fat dry milk in DPBS supplemented with 0.1% Tween-20) and washed 3 times in DPBS/0.1% Tween-20. The membrane is incubated overnight at 4° C. with a 1:250 dilution of monoclonal anti-COX-2 antibody (Transduction Laboratories) in blocking buffer. After 3 washes in DPBS/0.1% Tween-20, the membrane is incubated with a 1:1000 dilution of horseradish peroxidase-conjugated sheep antiserum to mouse Ig (Amersham) in blocking buffer for 1 h at room temperature. Then the membrane is washed again 3 times in DPBS/0.1% Tween-20 and an ECL detection system (SuperSignal™ CL-HRP Substrate System, Pierce) is used to determine the levels of expression of COX-2.
[0143] While we have hereinbefore presented a number of embodiments of this invention, it is apparent that our basic construction can be altered to provide other embodiments which utilize the methods of this invention. | The present invention relates to inhibitors of p38, a mammalian protein kinase involved cell proliferation, cell death and response to extracellular stimuli. The invention also relates to methods for producing these inhibitors. The invention also provides pharmaceutical compositions comprising the inhibitors of the invention and methods of utilizing those compositions in the treatment and prevention of various disorders. | 2 |
FIELD OF THE INVENTION
The present invention relates to a suction nozzle employed in an electric vacuum cleaner; and, more particularly, to a floor nozzle incorporating a compact nozzle detachably attached thereto.
BACKGROUND OF THE INVENTION
FIG. 21 represents an exemplary canister type vacuum cleaner including an extension tube 102 detachably attached to a suction nozzle 101 in a front distal end thereof and further coupled to a handle 103 and a hose 104 which extends from the handle 103 is connected with a main body 106 via a joint 105 . Such an electric vacuum cleaner is capable of efficiently cleaning the floor with the wide surfaced floor nozzle 101 , however, cleaning a surface that is smaller than the floor nozzle 101 , e.g., when cleaning the stairs, creates a problem of using the floor nozzle 101 . In general, such surfaces are cleaned with crevice nozzles and brush nozzles that are equipped with the electric vacuum cleaner as supplements to the floor nozzle 101 by removing the extension tube 102 from the handle 103 and engaging the supplement nozzle with the handle 103 .
However, the exchange of the suction heads is a great inconvenience to a user. Furthermore, due to rollers provided on the floor nozzle 101 for facilitating transportability thereof and disengaged extension tube 102 attached thereto, the disengaged extension tube 102 and the floor nozzle 101 are prevented from being stationary against a wall, thus a problem of placement thereof rises while being disengaged. A floor nozzle 101 that can easily be adaptively exchanged with a compatt nozzle in a narrow vacuuming space can greatly enhance the vacuuming process. Such effort is realized in the prior art, as illustrated in Japanese Patent Laid-Open Publication No. 2001-314358.
Special features of such an electric vacuum cleaner are in a suction nozzle thereof. As illustrated in FIG. 22 , a front distal end of an extension tube 213 is connected with a hollow brush nozzle 250 via a ball join 240 that enables a rotation in a vertical direction and a direction of rotation, wherein the brush nozzle 250 is detachably installed with an opening 211 a that is communicated with a suction inlet of the floor nozzle 210 . While the brush nozzle 250 is engaged with the floor nozzle 210 that is attached to the distal end of the extension tube 213 , an air passage is formed through the hollow brush nozzle 250 and the floor nozzle 210 , thereby enabling cleaning of the floor with the floor nozzle 210 . The brush nozzle 250 can be disengaged from the floor nozzle 210 by stepping on a release 320 . Such a configuration enables a user to manipulate settings of the brush nozzle 250 with the floor nozzle 210 without having to bend down, facilitating converting from cleaning the floor to cleaning the steps and narrow cleaning surfaces.
However, a height of the floor nozzle 210 of the conventional vacuum cleaner described above is high enough to be limited for usage thereof in a cleaning surface that has a low height clearance, consequently restricting the cleaning surfaces to be cleaned by the floor nozzle 210 .
Furthermore, there is a great difficulty to reorient the floor nozzle 210 to a desired direction by rotating the extension tube 213 , since the handle to operate the floor nozzle 210 is connected with the extension tube 213 which is connected at an incline with the ball joint 240 that is vertically placed on the floor nozzle 210 , consequently hindering an efficient cleaning using the floor nozzle 210 .
Moreover, since the brush nozzle 250 is connected with the extension tube 213 via the ball joint 240 that is vertically rotatable and also rotatable in the direction of rotation, when the brush nozzle 250 is disengaged from the floor nozzle 210 for cleaning, an instability of an angle at which the brush nozzles 250 rests creates a difficulty in cleaning.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to provide a floor nozzle and a mini nozzle for use in an electric vacuum cleaner capable of facilitating detachability thereof, thereby adding greater convenience.
In accordance with a preferred embodiment of the present invention, there is provided a suction nozzle for use in an electric vacuum cleaner, including: a floor nozzle; and a mini nozzle detachably secured to the floor nozzle, the mini nozzle including a suction head, a joint, and an extension tube, wherein one of either the suction head and the joint or the joint and the extension tube is coupled allowing a vertical motion and the other is rotatably coupled, and wherein the suction head is unrotatably secured onto the floor nozzle while forming an air communication with the floor nozzle.
In accordance with another preferred embodiment of the present invention, there is provided a suction nozzle for use in an electric vacuum cleaner, including: a floor nozzle having an elongated suction inlet and a drive portion protruding from approximately the center of the elongated suction inlet toward the rear; and a mini nozzle detachably secured to the floor nozzle, wherein the mini nozzle long in the longitudinal direction is detachably aligned with a recess provided along the suction inlet and the drive portion of the floor nozzle, while forming an air communication with the floor nozzle.
In accordance with still another preferred embodiment of the present invention, there is provided a suction nozzle for use in an electric vacuum cleaner, including: an electric blower for creating a suction; a floor nozzle communicated with the electric blower, for suctioning dirt on a surface to be cleaned; a mini nozzle detachably secured on the floor nozzle for suctioning dirt on the surface to be cleaned; a sensing means for detecting whether or not the mini nozzle is engaged in the floor nozzle; and a control means for controlling the power consumption of the electric blower, wherein the control means controls the power consumption of the electric blower according to the output of the sensing means.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of a vacuum cleaner in accordance with a first preferred embodiment of the present invention;
FIGS. 2A and 2B describe a plan view and a side elevational view of a suction nozzle of the vacuum cleaner, respectively;
FIGS. 3A , 3 B, and 3 C show a side elevational view, a bottom view, and a front view of a mini nozzle, respectively;
FIG. 4 offers a cross sectional view of the mini nozzle;
FIG. 5 is a plan view illustrating an internal configuration of a floor nozzle;
FIG. 6 provides a perspective view illustrating engaging or disengaging the mini nozzle to or from the floor nozzle;
FIG. 7 presents a cross sectional view of the mini nozzle engaged in the floor nozzle;
FIG. 8 depicts a floor nozzle disengaged from the floor nozzle;
FIG. 9 represents a floor nozzle engaged in the floor nozzle;
FIGS. 10A and 10B set forth a partial cross sectional view of a suction head in a rotatable status and a partial cross sectional view of a the suction head in a locked status preventing rotation thereof, respectively;
FIGS. 11A and 11B describe a mini nozzle performing suction on a flat surface to be cleaned and a cornered surface to be cleaned, respectively;
FIGS. 12A , 12 B, and 12 C illustrate the floor nozzle according to the positioning of a handle;
FIG. 13 is a block diagram illustrating an electrical connection of the electric vacuum cleaner of a second preferred embodiment in accordance with the present invention;
FIG. 14 presents a micro switch as a detection means;
FIG. 15 depicts an electrical resistor as the detection means;
FIG. 16 represents a graph illustrating a relationship between power consumption and flow rate;
FIG. 17 sets forth a schematic diagram illustrating a power consumption setting switch of the electric vacuum cleaner of a third preferred embodiment in accordance with the present invention;
FIG. 18 represents a graph illustrating a relationship between power consumption and flow rate of a fourth preferred embodiment in accordance with the present invention;
FIG. 19 represents a graph illustrating a relationship between power consumption and flow rate of a fifth preferred embodiment in accordance with the present invention;
FIG. 20 represents a graph illustrating a relationship between power consumption and flow rate of a sixth preferred embodiment in accordance with the present invention;
FIG. 21 depicts a perspective view of a prior art vacuum cleaner; and
FIG. 22 represents a perspective view of a suction nozzle of another prior art vacuum cleaner.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A first preferred embodiment will now be described with accompanying drawings. The preferred embodiments to be shown below are particular examples of the present invention and do not limit the technical scope of the present invention.
As illustrated in FIG. 1 , the preferred embodiment pertains to a canister type electric vacuum cleaner 1 and a suction nozzle 3 serving as a suction inlet. The electric vacuum cleaner 1 is configured as shown below. There is detachably provided the suction nozzle 3 at a distal end portion of an extension tube 2 coupled with a handle (control unit) 4 . A hose 6 coupled with the handle 4 is connected to a main body 7 of the electric vacuum cleaner via a hose joint 5 . The main body 7 incorporates an electric blower 1 a therein.
The suction nozzle 3 as illustrated in FIGS. 2A and 2B , includes a floor nozzle 11 and a mini nozzle 10 to be detachably secured onto the floor nozzle 11 . The mini nozzle 10 incorporates a joint 9 connected with a suction head 40 via a rotatable joint (means for rotatably joining) 8 , to be coupled with the extension tube 2 . The mini nozzle 10 detachably secured onto the floor nozzle 11 can be disengaged therefrom by stepping on a release lever 13 provided thereon, thereby releasing the mini nozzle 10 from the supporting recess 12 . A user can utilize the disengaged mini nozzle 10 to clean narrow spaces. Moreover, the mini nozzle 10 can be placed on the supporting recess 12 and gently pressed to be engaged with the floor nozzle 11 , which can be used to efficiently carry out vacuuming of the floor.
The mini nozzle 10 as shown in FIGS. 3A , 3 B, 3 C is long in the longitudinal direction and a bottom surface to be engaged with the floor nozzle 11 is in a shape of an arc. Near the contact points on the arc in the direction of the axis of the arc cleaning element 14 is provided thereon, wherein on both sides thereof, a bottom suction inlet 15 is provided and cleaning element is provided on respective surfaces. Furthermore, an end opening 16 , which communicates with the suction inlet 23 of the floor nozzle 11 , as will be described below. While the mini nozzle 10 is disengaged from the floor nozzle 11 , the end opening 16 biased with a spring is closed, only partially leaving the bottom thereof open by a cover 18 , as illustrated in FIG. 4 . The reference numeral 17 designates a pair of feed contact points for forming feed contact points with a motor 21 for supplying rotation to the rotational brush provided in the floor nozzle 11 , which is wired from the main body 7 through the hose 6 , handle 4 , and extension tube 2 , to be wired with the distal end of the extension tube 2 . When the mini nozzle 10 is connected with the extension tube 2 through the joint 9 , a power feed portion 19 provided in the joint 9 is electrically wired to the end wire of the extension tube 2 , the mini nozzle 10 is wired with the power feed portion 19 and thus wired with the feed contact point 17 .
The cleaning element 14 has napped fibers on a sheet. By utilizing such cleaning element 14 to cover both sides of the bottom suction inlet 15 , the suctioning force in the bottom suction inlet 15 is improved. Further, according to the motion of the mini nozzle 10 , the dirt in a recess portion is collected toward the bottom suction inlet 15 , thereby cleaning the surface to be cleaned and at the same time serving as a bumper, preventing damages to furniture or the surface to be cleaned. The cleaning element 14 is preferably chosen for the mini nozzle 10 , however, other material such as felt can be elected.
Moreover, the bottom suction inlet 15 formed on the bottom surface of the mini nozzle 10 is in two rows, however may be formed in a single row near the contract point portions of the arc and placing cleaning element 14 on both sides.
The floor nozzle 11 as illustrated in FIG. 5 is of a power nozzle. A rotation brush 20 including a brush and a rubber blade attached to an axle is connected with a motor 21 by a belt 21 a for providing rotation thereto, which serves to collect dirt from carpets. A power feed for the motor 21 is placed on the mini nozzle 10 . A pair of power feed contact points 17 of the mini nozzle 10 slidably contacts a pair of power receiving contact points 22 located on the floor nozzle 11 .
The floor nozzle 11 includes a suction member 24 incorporating a wide suction inlet 23 hosting the rotational brush 20 . A drive portion 25 is formed from about the center of the suction inlet 23 and protruding toward the rear, forming a T-shape from a plan view. As illustrated in FIG. 6 , a recess 26 for hosting therein the mini nozzle 10 is provided along a top portion of an end portion of the drive portion 25 and the suction member 24 . Upon placement of the mini nozzle 10 in the recess 26 , the cover 18 of the end opening 16 is opened, to thereby form an air communication between an end portion of the end opening 16 and air passage inlet 27 , further forming an air communication with the main body 7 .
FIG. 7 illustrates cross sectional view of the mini nozzle 10 engaged with the floor nozzle 11 . Upon engaging the mini nozzle 10 onto the floor nozzle 11 , an open/close control rib 28 (a means for opening and closing the suction inlet of the end portion), which protrudes from a front region of the recess 26 toward the rear thereof, rotates the cover 18 that partially closes by a spring the end opening 16 of the mini nozzle 10 ; and due to the resistance of the spring, the cover 18 and the end opening 16 are completely opened, to thereby form an air communication from a suction inlet 23 through the joint 9 . Moreover, the bottom suction inlet 15 of the mini nozzle 10 is blocked by the bottom surface of the recess 26 , accordingly while the mini nozzle 10 is engaged with the floor nozzle 11 , the suction is concentrated only at the suction inlet 23 , and thus the suction force of the floor nozzle 11 is not compromised by the engaging of the mini nozzle 10 .
As illustrated in FIG. 6 , the recess 26 is provided with a depth substantially equivalent to a height of the mini nozzle 10 , such that when the mini nozzle 10 is placed in the recess 26 , the mini nozzle is flatly integrated into the floor nozzle 11 with minor protrusion of the mini nozzle 10 on the top surface of the floor nozzle 11 , as illustrated in FIGS. 2B and 7 . Moreover, the height of the floor nozzle 11 is reduced by using small radius wheels 36 on both sides of the recess 26 as shown in FIG. 2 .
The mini nozzle 10 can be released from the floor nozzle 11 by pressing down (stepping) on a release lever 13 . As illustrated in FIG. 4 , the cover 18 closes the end opening 16 located thereon by the spring, since the open/close control rib 28 (a means for opening and closing the cover 18 ) no longer exerts force thereto. A vertical dimension of the cover 18 is established to be smaller than the height of the end opening 16 , and thus leaving a clearance in the bottom portion of the end opening 16 , and partially closing the end opening 16 . Moreover, since the bottom suction inlet 15 is opened, a lower portion of the end opening 16 and a plurality of the bottom suction inlets 15 form an air communication through the joint 9 , to thereby enable dust collection by the mini nozzle 10 .
A mechanism of engaging and disengaging of the mini nozzle 10 with/from the floor nozzle 11 will hereinafter be explained with reference to FIGS. 8 and 9 .
Referring to FIGS. 8 and 9 , there is provided a support 12 (a means for disengaging and engaging the mini nozzle) in the recess 26 provided in the floor nozzle 11 according to a cross section thereof. The support 12 is attached at the left and the right of the hinge portion in approximately the center thereof, such that a release status as shown in FIG. 8 and a secured status as shown in FIG. 9 can adaptively be controlled. More specifically, during the release status as shown in FIG. 8 , the mini nozzle 10 can be disengaged by pressing down on the release lever 13 ; and during the secured status as shown in FIG. 9 , the mini nozzle 10 can be engaged with the floor nozzle 11 by inserting the mini nozzle 10 into the support 12 .
During the release status as shown in FIG. 8 , the support 12 is unfolded at the left and the right of the hinge portion in approximately the center thereof. Upon inserting the mini nozzle 10 in the support 12 , a pressure member 29 placed in an approximately the center of the hinge portion is lowered and exerts force between cleaning element 14 partitioned in front and rear of a top portion of the side of the arc of the mini nozzle 10 , such that the support 12 is lowered to the bottom surface of the recess 26 and as illustrated in FIG. 9 the suction head 40 portion of the mini nozzle 10 is surrounded and secured thereby. While the pressure member 29 is lowered, a moving member 32 pushes down on one of the ends of a rod 30 axially supporting a supporting member 31 connected thereto. Accordingly, a release lever 13 placed on the other end of the rod 30 is raised as illustrated in FIG. 9 . A disengaging and engaging unit 38 of the mini nozzle 10 includes the pressure member 29 , the rod 30 , the supporting member 31 , moving member 32 , and the support 12 . The supporting member 31 serves as a fulcrum for the rod 30 and the rod 31 is downwardly biased with an elastic spring 31 a , to thereby support the mini nozzle 10 .
There are provided outwardly biased pins 33 on both sides of the mini nozzle 10 in order to effectively secure the mini nozzle 10 onto the support 12 and corresponding recesses 34 in the support 12 , so that when the mini nozzle 10 is inserted into the support 12 , the pins 33 are secured in the recesses 34 , and thus providing a more stable support of the mini nozzle 10 in the floor nozzle 11 . Furthermore, there is provided a recess 35 for hosting the cleaning element 14 on the mini nozzle 10 , as to prevent the cleaning element 14 from interfering with the securing of the mini nozzle 10 .
The release lever 13 in an up position is pressed down, in order to release the mini nozzle 10 from the floor nozzle 11 in a secured status as illustrated in FIG. 9 , at which time the rod 30 is rotated about the supporting member 31 and raises the hinge portion of the support 12 by the moving member 32 . Thus, the support 12 is opened and the mini nozzle 10 is raised due to the pressure member 29 , thereby disengaging the mini nozzle 10 from the floor nozzle 11 .
The rotatable joint 8 which is connected rotatably in a vertical and horizontal direction is provided between the suction head 40 and the joint 9 in the mini nozzle 10 as described. And as illustrated in FIGS. 2 and 7 , when the mini nozzle 10 is engaged with the floor nozzle 11 , the rotatable joint 8 engages in a vertical and horizontal motion corresponding to the motion of the handle 4 connected with the joint 9 via the extension tube 2 , that is when the handle 4 is manipulated so that floor nozzle 11 changes position in a horizontal direction, due to the rotatable joint 8 horizontally rotatable provided in the back of the floor nozzle 11 , the rotational motion is applied to the floor nozzle 11 , and consequently enabling a change of direction for the floor nozzle 11 .
When using the mini nozzle 10 disengaged from the floor nozzle 11 , there is a great difficulty in manipulating the mini nozzle in a horizontal direction. Accordingly, there is a need for a locking mechanism, which prevents the rotatable joint 8 from engaging in a horizontal rotation. Such a locking mechanism as illustrate in FIGS. 10A and 10B , there is provided a lock 42 which pops in and out in the rotational path of the rotational motion rib 41 of the rotatable joint 8 of the mini nozzle 10 , such that when the mini nozzle 10 is engaged with the floor nozzle 11 , the lock 42 is removed from the rotational path by the support 12 , however, when the mini nozzle 10 is disengaged from the floor nozzle 11 , the lock protrudes into the rotational path.
When the mini nozzle 10 is disengaged from the floor nozzle 11 , the lock 42 protrudes into the rotational path of the rotational motion rib 41 of the rotational joint 8 and locks the rotational motion. Consequently, only a vertical motion is permitted between the rotatable joint 8 and the joint 9 , thereby facilitating the usage of the vacuum, since the surface of the suction head 40 which faces the surface to be cleaned, of the mini nozzle 10 rotates in a horizontal direction.
As another alternative to such a locking mechanism, a spring biased stopper may be installed (not illustrated), such that when the mini nozzle 10 is engaged with the floor nozzle 11 , an overriding mechanism provided on the floor nozzle 11 resisting the spring force removes the stopper from restricting the rotation, and thus when the mini nozzle 10 is placed in the floor nozzle 11 , the stopper does not restrict the rotation, enabling a vertical and horizontal rotation of the floor nozzle 11 , while restricting such rotation when the mini nozzle 10 is disengaged from the floor nozzle 11 .
In an electric vacuum cleaner 1 employing such a configuration of the suction inlet 3 described above, when the mini nozzle 10 is engaged with the floor nozzle 11 , the wide floor nozzle 11 can effectively perform vacuum cleaning on a surface to be cleaned as the conventional vacuum cleaner. In a case of a narrow space, e.g., stairway, that is inaccessible with the floor nozzle 11 , the released lever 13 can be stepped on, without the user having to bend down, to disengage the mini nozzle 10 from the floor nozzle 11 , to thereby enable a vacuum cleaning with the mini nozzle 10 . The user is relieved from having to exchange the end nozzle. Moreover, the floor nozzle 11 which is disengaged from the mini nozzle 10 is placed on the surface to be cleaned. Accordingly, the user may simply insert the mini nozzle 10 into the floor nozzle 11 to swiftly switch on a surface to be cleaned.
When the mini nozzle 10 is disengaged with the floor nozzle 11 , since the bottom suction inlet 15 is formed of a shape of an arc, as illustrated in FIG. 11 , the mini nozzle 10 can be at any discretionary angle. In particular, as shown in FIG. 11B , the dust in corners formed by walls or furniture can be collected by the suction of the bottom suction inlet 15 . Moreover, the end opening 16 of the mini nozzle 10 as described is partially closed by the cover 18 leaving a gap in a bottom portion thereof, when the mini nozzle 10 is disengaged from the floor nozzle 11 , and thus the cross sectional area of the opening is reduced and thereby increasing the suction velocity. Since the opening is near the surface to be cleaned, the dust collection capacity is enhanced on the mini nozzle 10 , enabling a greater range of vacuum cleaning. Moreover, if the end opening 16 is configured to be entirely closed by the cover 18 , the suction capacity of the bottom suction inlet 15 can further be enhanced.
When the mini nozzle 10 is engaged with the floor nozzle 11 , the mini nozzle 10 can be engaged in a vertical and horizontal motion by the rotatable joint 8 and the joint 9 , and accordingly, the floor nozzle 11 can be rotated in any direction as illustrated in FIGS. 12A to 12C .
A joining portion of the suction head 40 and the rotatable joint 8 is horizontally rotatable with the mini nozzle 10 , and thus as shown in FIG. 9 , the entire suction inlet of the floor nozzle 11 can face the surface to be cleaned while coinciding with the direction of the end of the axis of the extension tube 2 , thereby allowing a user to efficiently perform vacuum cleaning in a narrow space. And the mini nozzle 10 as described above is rotatably connected in a vertical and horizontal direction with a joining portion of the suction head 40 , rotatable joint 8 and joint 9 , and thus the joining portion between the suction inlet and the main body 1 is not rotatable, thereby improving airtightness thereof. Moreover, regardless of improving the airtightness, since the vertical and horizontal rotation takes place between the suction head 40 of the mini nozzle 10 , the rotatable joint 8 , and the joint 9 , the controllability is not compromised.
Furthermore, a small radius wheel 36 is provided in a rear portion of the floor nozzle 11 , where the rotation of the rotatable joint 8 of the mini nozzle 10 takes place, so to prevent a sliding or rising of the floor nozzle 11 about a small radius wheel 36 provided in a rear portion of the floor nozzle 11 when inserting the mini nozzle 10 into the floor nozzle 11 by the handle 4 .
The configuration of the suction inlet 3 of the preferred embodiment may be applicable to a hand vacuum cleaner having a short suction path in a main body thereof having a handle thereon, and enhancing capacity thereof.
A second preferred embodiment in accordance with the present invention will now be described with reference to FIGS. 13 to 16 . Parts that are substantially identical to those shown above will employ the same reference numerals and elaboration thereof will be omitted.
In referring to FIG. 13 , reference numeral 50 arranged in series with AC 51 , designates a means for operating an electric blower 1 a included in a main body 7 . A detecting means 52 is provided in the mini nozzle 10 , which detects the connectivity between the floor nozzle 11 and the mini nozzle 10 . In the first preferred embodiment, the floor nozzle 11 and the mini nozzle 10 are electrically connected via a pair of power feed contact points 17 provided in the mini nozzle 10 and a pair of receiving contact points 22 in the floor nozzle 11 , however, in the second preferred embodiment, the configuration of the connection will be described below.
Moreover, a suction inlet 23 of a floor nozzle 11 has a greater opening area than a bottom suction inlet 15 and an end opening 15 of the mini nozzle 10 . In addition, the electric vacuum cleaner of the second preferred embodiment is equipped with a rechargeable battery.
A reference numeral 53 is placed inside a handle 45 and is a means for selecting a level of power based on the condition of the surface to be cleaned, that is the user may select the level of suction, e.g., High, Mid, Low, Off, generated by the electric blower 1 a . According to a user input, the control variables of the phase of the electric blower operation means 50 is determined. The reference numeral 54 determines the power supplied (control variables of the phase) to the electric blower 1 a according to the detecting means 52 output and the user selected drive position of the power selecting means 53 , thereby controlling the power supplied (control variables of the phase) to the electric blower 1 a . The electric blower operating means 50 operates the electric blower 1 a through the control means 54 .
FIG. 14 illustrates the connection between the floor nozzle 11 and the mini nozzle 10 . Provided in a connection portion of the floor nozzle 11 is a connection pin 56 and a detection rib 57 to be electrically connected with a connection terminal 55 place on the mini nozzle 10 . Moreover, as a means for detection 52 in the mini nozzle 10 , in a position corresponding to detection rib 57 is a micro switch 58 equipped with a moving panel 59 . Under such configuration, if the floor nozzle 11 is inserted to the mini nozzle 10 to be connected, the detection rib 57 presses the moving panel 59 of the micro switch 58 and turns the micro switch to ON position, thereby enabling the floor nozzle 11 to detect the connectivity thereof with the mini nozzle 10 .
As illustrated in FIG. 15 , similar to the floor nozzle 11 , the mini nozzle 10 has a detection rib 57 and at a corresponding position thereof, having one end fixed and the other having a slide rib 60 varying electrical resistance connected with a resistor 62 having a spring 61 . Under such configuration the detection rib 57 presses the slide rib 60 , and varying the resistance of the resistor 62 , thereby detecting the connectivity of the floor nozzle 11 , as described above. Furthermore, in a case of unconnected floor nozzle 11 , the spring 61 connected to the slide rib 60 and spring force thereby returns it to the original position. In place of the micro switch 58 and the electrical resistor 62 , a capacitor (not illustrated) may be employed. Comparing the electric current in the capacitor while in connection and not in connection can provide information about connectivity thereof.
The operation based on the configuration described above is explained hereinafter. A user selects the power section means 53 to be on High, while the floor nozzle 11 is connected. As illustrated in FIG. 16 , the electric blower 1 a is controlled in order to obtain a power consumption level (control variable of the phase) of W 1 . In a similar manner, Mid was selected in order to obtain the power consumption rate of W 2 , and Low to obtain W 3 . According to a selection position of the power selection means 53 , the control means 54 controls the electric blower 1 a based on the pre-specified controlled variables of the phase, through the electric blower control means 50 .
If the mini nozzle 10 is disengaged from the floor nozzle 11 , the detection means 52 detects the disengaged status. According to the output of the detection means 52 the control means 54 adjusts the control variables of the phase, so that the power supplied W 1 at the High position is at maximum in an upper limit of the power supply and allocates sufficient suction flow rate, to thereby enable an effective vacuum cleaning.
A third preferred embodiment in accordance with the present invention will be explained with reference to FIG. 17 . Referring to FIG. 17 , the power selection means 63 includes a mode selection switch and a mini mode switch. In a mode selection switch a user determines the setting, e.g., High, Mid, Low, Off, of the suction flow rate of an electric blower 1 a , according to a condition of a surface to be cleaned. The mini mode switch for selecting the power of the electric blower 1 a in order to maintain the performance of cleaning while using the mini nozzle 10 . The setting on respective switches can be determined by the user, thereby adding greater convenience. Furthermore, the mini mode switch can be placed on a main body 7 of the electric vacuum cleaner.
A fourth preferred embodiment in accordance with the present invention will now be explained with reference to FIG. 18 . If a detection means 52 placed in a mini nozzle 10 detects the mini nozzle 10 to be disengaged from the floor nozzle 11 , the power setting of an electric blower 1 a is established at High position and the power consumption W 1 to be at maximum power and for Mid and Low positions, power consumptions are adjusted to W 4 or W 5 , which are higher than the pre-specified drive setting power consumptions W 2 or W 3 by the control means 54 , so that when mini nozzle 10 is disengaged from the floor nozzle, the power of the electric blower 1 a is increased, so that a sufficient suction flow rate is allocated and maintained, thereby enabling an effective vacuum cleaning.
A fifth preferred embodiment in accordance with the present invention is explained with reference to FIG. 19 . If a detection means 52 placed in a mini nozzle 10 detects the mini nozzle 10 to be disengaged from the floor nozzle 11 , the power setting of an electric blower 1 a is established at Low position and the power consumption W 3 to be at minimum power and for High and Mid positions, power consumptions are adjusted to W 8 or W 9 , which are lower than the pre-specified drive setting power consumptions W 1 or W 2 by the control means 54 , so that when mini nozzle 10 is disengaged from the floor nozzle, so that when the mini nozzle 10 is solely operated, the power of the electric blower 1 a is reduced as to reduce power consumption and reduces noise associated therewith and maintain performance of the electric vacuum cleaner.
A sixth preferred embodiment in accordance with the present invention will now be explained with reference to FIG. 20 . If a detection means 52 placed in a mini nozzle 10 detects the mini nozzle 10 to be disengaged from the floor nozzle 11 having a rotational brush, the power setting of an electric blower 1 a is established at Low position and the power consumption W 3 to be at minimum power and for High and Mid positions, power consumptions are adjusted to W 10 or W 11 , which are lower than the pre-specified drive setting power consumptions W 1 or W 2 by the control means 54 , so that when mini nozzle 10 is disengaged from the floor nozzle, the power of the electric blower 1 a is increased, so that when the floor nozzle 11 equipped with the rotational brush is connected, the power of the electric blower 1 a is reduced as to reduce power consumption and noise associated therewith and maintain performance of the electric vacuum cleaner.
While the invention has been shown and described with respect to the preferred embodiment, it will be understood to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. | A suction nozzle for use in a vacuum cleaner includes a floor nozzle and a mini nozzle having a suction head, a rotatable joint, and joint, to be detachably secured in the floor nozzle. Either of the suction head and the rotatable joint or the rotatable joint and the joint is vertically joined and the other rotatably joined. Moreover, the suction head is unrotatably secured onto the floor nozzle, and forms an air communication with the floor nozzle. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the National Phase of PCT/KR2009/001414 filed on Mar. 19, 2009, which claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 61/037,709 filed on Mar. 19, 2008 and U.S. Provisional Application No. 61/039,433 filed on Mar. 26, 2008 and under 35 U.S.C. 119(a) to Patent Application No. 10-2008-0073148 filed in Republic of Korean on Jul. 25, 2008, all of which are hereby expressly incorporated by reference into the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method of transmitting a frame consisting of orthogonal frequency-division multiplexing (OFDM) symbols having various cyclic prefix (CP) lengths for each subframe in a wireless communication system.
2. Related Art
The institute of electrical and electronics engineers (IEEE) 802.16 standard provides a technique and protocol for supporting broadband wireless access. The standardization had been conducted since 1999 until the IEEE 802.16-2001 was approved in 2001. The IEEE 802.16-2001 is based on a physical layer of a single carrier (SC) called ‘WirelessMAN-SC’. The IEEE 802.16a standard was approved in 2003. In the IEEE 802.16a standard, ‘WirelessMAN-OFDM’ and ‘WirelessMAN-OFDMA’ are further added to the physical layer in addition to the ‘WirelessMAN-SC’. After completion of the IEEE 802.16a standard, the revised IEEE 802.16-2004 standard was approved in 2004. To correct bugs and errors of the IEEE 802.16-2004 standard, the IEEE 802.16-2004/Cor1 (hereinafter, IEEE 802.16e) was completed in 2005 in a format of ‘corrigendum’.
Recently, standardization on the IEEE 802.16m is in progress as a new technical standard based on the IEEE 802.16e. The IEEE 802.16m, which is a newly developed technical standard, has to be designed to support the previously designed IEEE 802.16e. That is, a technology (i.e., IEEE 802.16m) of a newly designed system has to be configured to operate by effectively incorporating a conventional technology (i.e., IEEE 802.16e). This is referred to as backward compatibility.
A base station (BS) employing a new technology performs scheduling on a radio resource with respect to a legacy user equipment (UE) or a UE employing the new technology at a bandwidth that can be supported by the BS. Scheduling of the radio resource can be performed in a logical frame consisting of a plurality of OFDM symbols in a time domain and a plurality of subchannels in a frequency domain. Therefore, there is on-going research on a frame structure in which an IEEE 802.16m system can satisfy backward compatibility with respect to an IEEE 802.16e system.
At present, as a frame structure in which the IEEE 802.16m system can satisfy backward compatibility with respect to the IEEE 802.16e system, a frame structure consisting of an OFDM symbol of which a cyclic prefix (CP) length is ⅛ times of a useful symbol time Tu is proposed. However, a frame structure consisting of an OFDM symbol having another CP length other than the ⅛ times of the useful symbol time is not clearly proposed yet.
Accordingly, when an IEEE 802.16m system supporting a frame structure consisting of an OFDM symbol having another CP length other than ⅛ Tu exists in a neighbor cell, there is a need to design the frame structure such that interference does not occur between systems in neighboring cells. In addition, there is a need to design the frame structure such that frame structures consisting of OFDM symbols having different CP lengths coexist in the same cell or subframe structures consisting of OFDM symbols having different CP lengths coexist in one frame.
SUMMARY OF THE INVENTION
The present invention provides a subframe structure consisting of orthogonal frequency-division multiplexing (OFDM) symbols having various cyclic prefix (CP) lengths.
In an aspect, a method of transmitting a frame in a wireless communication system is provided. The method include configuring a first frame including a plurality of first subframes, configuring a second frame including plurality of second subframes, and transmitting the second frame, wherein the first subframe and the second subframe include a plurality of orthogonal frequency division multiplexing (OFDM) symbols, an OFDM symbol included in the first subframe and an OFDM symbol included in the second subframe have different cyclic prefix (CP) lengths with each other, and the first subframe and the second subframe have the same length.
In another aspect, a method of transmitting a frame in a wireless communication system is provided. The method include configuring a frame including a plurality of subframes, and transmitting the frame, wherein the subframe comprises a plurality of orthogonal frequency-division multiplexing (OFDM) symbols, a cyclic prefix (CP) length of the OFDM symbol included in the subframe is selected independently for each subframe, and the plurality of subframes have the same length.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a wireless communication system.
FIG. 2 shows an example of a frame structure.
FIG. 3 shows an example of a TDD frame which consists of an OFDM symbol having a CP length of ⅛ Tu and which supports a new system while having similarity with a TDD frame structure of a legacy system.
FIG. 4 shows a subframe structure according to an embodiment of the present invention.
FIG. 5 shows another subframe structure according to an embodiment of the present invention.
FIG. 6 shows another subframe structure according to an embodiment of the present invention.
FIG. 7 shows another subframe structure according to an embodiment of the present invention.
FIG. 8 shows another subframe structure according to an embodiment of the present invention.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 shows a wireless communication system. The wireless communication system can be widely deployed to provide a variety of communication services, such as voices, packet data, etc.
Referring to FIG. 1 , the wireless communication system includes at least one user equipment (UE) 10 and a base station (BS) 20 . The UE 10 may be fixed or mobile, and may be referred to as another terminology, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device, etc. The BS 20 is generally a fixed station that communicates with the UE 10 and may be referred to as another terminology, such as a node-B, a base transceiver system (BTS), an access point, etc. There may be one or more cells within the coverage of the BS 20 .
A downlink (DL) represents a communication link from the BS 20 to the UE 10 , and an uplink (UL) represents a communication link from the UE 10 to the BS 20 . In the DL, a transmitter may be a part of the BS 20 , and a receiver may be a part of the UE 10 . In the UL, the transmitter may be a part of the UE 10 , and the receiver may be a part of the BS 20 .
There is no restriction on the multiple access scheme used in the wireless communication system. Examples of the multiple access scheme are various, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), single-carrier FDMA (SC-FDMA), and orthogonal frequency division multiple access (OFDMA).
The BS 20 has at least one cell. The cell is an area in which the BS 20 provides a communication service. Different communication schemes can be used in one cell. That is, heterogeneous wireless communication systems may exist while sharing a communication service area. Hereinafter, the heterogeneous wireless communication systems or heterogeneous systems refer to systems using different communication schemes. For example, the heterogeneous systems may be systems using different access schemes, or may be a legacy system and an evolution system supporting backward compatibility with the legacy system.
FIG. 2 shows an example of a frame structure. A frame is a data sequence used according to a physical specification in a fixed time duration. The frame is a logical frame, and section 8.4.4.2 of the IEEE standard 802.16-2004 “Part 16: Air Interface for Fixed Broadband Wireless Access Systems” can be incorporated herein by reference.
Referring to FIG. 2 , the frame includes a downlink (DL) frame and an uplink (UL) frame. DL transmission is performed using the DL frame, and UL transmission is performed using the UL frame. When using a time division duplex (TDD) scheme, the UL and DL transmissions are achieved at different times while sharing the same frequency band. The DL frame temporally precedes the UL frame. The DL frame sequentially includes a preamble, a frame control header (FCH), a DL-MAP, a UL-MAP, and a burst region. Guard times are provided to identify the UL frame and the DL frame and are inserted to a middle portion (between the DL frame and the UL frame) and a last portion (next to the UL frame) of the frame. A transmit/receive transition gap (TTG) is a gap between a DL burst and a subsequent UL burst. A receive/transmit transition gap (RTG) is a gap between a UL burst and a subsequent DL burst.
The preamble is used between a BS and a UE for initial synchronization, cell search, and frequency-offset and channel estimation. The FCH includes information on a length of a DL-MAP message and a coding scheme of the DL-MAP.
The DL-MAP is a region for transmitting the DL-MAP message. The DL-MAP message defines access to a DL channel. The DL-MAP message includes a configuration change count of a downlink channel descriptor (DCD) and a BS identifier (ID). The DCD describes a downlink burst profile applied to a current MAP. The downlink burst profile indicates characteristics of a DL physical channel. The DCD is periodically transmitted by the BS by using a DCD message.
The UL-MAP is a region for transmitting a UL-MAP message. The UL-MAP message defines access to a UL channel. The UL-MAP message includes a configuration change count of an uplink channel descriptor (UCD) and also includes an effective start time of uplink allocation defined by the UL-MAP. The UCD describes an uplink burst profile. The uplink burst profile indicates characteristics of a UL physical channel and is periodically transmitted by the BS by using a UCD message.
Table 1 shows an example of parameters for a frame.
TABLE 1
Transmission Bandwidth (MHz)
5
10
20
Over-sampling factor
28/25
Sampling Frequency (MHz)
5.6
11.2
22.4
FFT Size
512
1024
2048
Sub-carrier Spacing (kHz)
10.94
OFDM symbol time, Tu (us)
91.4
Cyclic Prefix (CP)
Ts (us)
OFDM symbols
Idle time (us)
per Frame
Tg = 1/4 Tu
91.4 + 22.85 = 114.25
43
87.25
Tg = 1/8 Tu
91.4 + 11.42 = 102.82
48
64.64
Tg = 1/16 Tu
91.4 + 5.71 = 97.11
51
47.39
Tg = 1/32 Tu
91.4 + 2.86 = 94.26
53
4.22
As shown in Table 1 above, an OFDM symbol has a different length according to a CP length.
The OFDM symbol is generated by using inverse Fourier transform. A time duration of the OFDM symbol is denoted by a useful symbol time Tu. A CP is a copy of a final useful symbol time Tg, and can be denoted by a ratio with respect to the useful symbol time Tu. That is, the length of one OFDM symbol is the sum of the CP length and the useful symbol time Tu.
Hereinafter, a time division duplexing (TDD) frame structure in which some of the parameters proposed in Table 1 above are extracted is defined as a frame structure of a legacy system. Herein, the TDD frame denotes a frame in which UL and DL are divided in a time domain while a full frequency band is used for UL or DL. The legacy system may imply a wireless communication system using the IEEE 802.16e standard technique, and the new system may imply a wireless communication system using the IEEE 802.16m standard technique. In a frame of the legacy system, a CP length of an OFDM symbol constituting the frame is ⅛ times of the useful symbol time Tu, and control information such as a preamble, an FCH, a DL-MAP, etc., is defined according to the IEEE 802.16e standard. The preamble, the FCH, and the DL-MAP can be referred to as essential control information required by a UE to perform communication by accessing a system network. The frame may have a size of 5 ms. The essential control information is allocated first temporally in the frame.
FIG. 3 shows an example of a TDD frame which consists of an OFDM symbol having a CP length of ⅛ Tu and which supports a new system while having similarity with a TDD frame structure of a legacy system.
Referring to FIG. 3 , the frame has a length of 5 ms, and includes 8 subframes and an idle time. One subframe has a length of 0.617 ms, and includes 6 OFDM symbols. Herein, SF k denotes a k th subframe. Although the TDD frame structure is shown in FIG. 3 , a frequency division duplexing (FDD) frame structure has similarity with the TDD frame structure. In the FDD frame, UL transmission and DL transmission are performed simultaneously while occupying different frequency bands.
As shown in FIG. 3 , when 6 OFDM symbols constitute one subframe, a ratio of a DL duration and a UL duration can be effectively configured in the TDD frame, the number of OFDM symbols of the UL duration can be set to a multiple of 3, and data delay can be reduced.
In addition, if a frame consists of an OFDM symbol having a CP length of ⅛ Tu similarly to the frame structure of the legacy system, the frame structure of the legacy system and the frame structure of the new system have an overlapping TTG duration, and thus interference between UEs located in a cell edge can be avoided when the legacy system and the new system coexist between neighboring cells.
However, FIG. 3 shows an example of a frame consisting of an OFDM symbol having a CP length of ⅛ Tu. If a new system considering a frame structure consisting of an OFDM symbol having another CP length other than ⅛ Tu exists in a neighboring cell, similarity between frames is required in order for coexistence of the two systems. In addition, frame design is achieved such that frames consisting of OFDM symbols having different CP lengths coexist in one cell, or subframes consisting of OFDM symbols having different CP lengths coexist in one frame.
The frame supporting the new system includes a plurality of subframes divided in a specific-sized duration. In general, data allocation and scheduling are performed in a subframe unit. In addition, in the TDD frame, a DL duration and a UL duration can be divided in the subframe unit. One subframe consists of OFDM symbols having the same CP length. Each subframe may consist of an OFDM symbol having a different CP length. Therefore, to satisfy coexistence without mutual interference with a frame consisting of an OFDM symbol having a CP length of ⅛ Tu between the legacy system and the new system, it can be considered to allow a subframe consisting of OFDM symbols having various CP lengths to have similarity with a subframe for constituting a frame consisting of an OFDM symbol having a CP length of ⅛ Tu. That is, the present invention proposes a subframe structure in which all subframes are configured to have the same length irrespective of a CP length so as to satisfy coexistence between frames or subframes even if a CP length is different.
Hereinafter, various embodiments in which subframes consisting of OFDM symbols having various CP lengths are configured to have the same length will be described.
FIG. 4 to FIG. 8 shows examples where a transmission bandwidth is 10 MHz. Referring to Table 1 above, when the transmission bandwidth is 10 MHz, a sampling frequency is 11.2 MHz, and thus one sample interval is 1/11.2 MHz=89.2 ns. Although the TDD frame structure is exemplified in FIG. 4 to FIG. 8 , the present invention can equally apply to the FDD frame structure.
FIG. 4 shows a subframe structure according to an embodiment of the present invention. Herein, SF k denotes a k th subframe, and S k denotes a k th OFDM symbol in a subframe.
Referring to FIG. 4 , a subframe consisting of an OFDM symbol having a CP length of ⅛ Tu is configured with 6 OFDM symbols, and a subframe consisting of an OFDM symbol having a different CP length is configured to have the same length of a subframe consisting of an OFDM symbol having a CP length of ⅛ Tu. That is, a subframe consisting of an OFDM symbol having a CP length other than ⅛ Tu may include an OFDM symbol fraction and an idle duration in order to adjust to the length of the OFDM symbol having the CP length of ⅛ Tu. For example, a subframe consisting of an OFDM symbol having a CP length of ¼ Tu includes 5 OFDM symbols and a ¼ OFDM symbol fraction, a subframe consisting of an OFDM symbol having a CP length of 1/16 Tu includes 6 OFDM symbols, a ¼ OFDM symbol fraction, and an idle duration of 64 samples, and a subframe consisting of an OFDM symbol having a CP length of 1/32 Tu includes 6 OFDM symbols, a ½ OFDM symbol fraction, and an idle duration of 32 samples. Herein, the CP length of the OFDM symbol fraction is equal to the CP length of the OFDM symbol constituting the subframe including the OFDM symbol fraction.
In the subframes consisting of the OFDM symbols having the CP lengths of ¼ Tu, 1/16 Tu, and 1/32 Tu shown in FIG. 4 , the OFDM symbol fraction or the idle duration is located in an end portion temporally in a frame. However, the present invention is not limited thereto, and thus the OFDM symbol fraction or the idle duration may be located in a front portion of the subframe or between OFDM symbols.
Table 2 shows a configuration of a subframe based on FIG. 4 .
TABLE 2
Number of Samples(10 MHz)
CP Length
CP
m/n = CP Length/Useful OFDM Symbol Length
(Tu = 1024
Duration
Idle Per
Samples)
(Samples)
#0
#1
#2
#3
#4
#5
#6
Subframe
1/8 Tu
128
128/1024
128/1024
128/1024
124/1024
128/1024
128/1024
N/A
0
1/4 Tu
256
256/1024
256/1024
256/1024
256/1024
256/1024
256/256
N/A
0
1/16 Tu
64
64/1024
64/1024
64/1024
64/1024
64/1024
64/1024
64/256
64
1/32 Tu
32
32/1024
32/1024
32/1024
32/1024
32/1024
32/1024
32/512
32
Although the OFDM symbol fraction is located in a 6 th symbol duration in Table 2, this is for exemplary purposes only, and thus the OFDM symbol fraction can be located in any symbol duration.
FIG. 5 shows a subframe structure according to another embodiment of the present invention. Herein, SF k denotes a k th subframe, and S k denotes a k th OFDM symbol in a subframe.
Referring to FIG. 5 , the frame structure is the same as the subframe structure of FIG. 4 , except for an idle duration of subframes consisting of OFDM symbols having CP lengths of 1/16 Tu and 1/32 Tu. Herein, a duration corresponding to the idle duration of FIG. 4 can be used as a CP duration of any OFDM symbol in the subframe. For example, the duration corresponding to the idle duration of FIG. 4 may be located in front of a ¼ OFDM symbol fraction of a subframe consisting of an OFDM symbol having a CP length of 1/16 Tu and in front of a ½ OFDM symbol fraction of a subframe consisting of an OFDM symbol having a CP length of 1/32 Tu. Therefore, the CP length of the OFDM symbol fraction is two times higher than the CP length of the OFDM symbol constituting the subframe including the OFDM symbol fraction.
Although the duration corresponding to the idle duration is located in front of the OFDM symbol fraction in FIG. 5 , the present invention is not limited thereto, and thus the duration may be located in front of another OFDM symbol. In addition, although the OFDM symbol fraction is located in a 6 th symbol duration, the present invention is not limited thereto, and thus the OFDM symbol fraction can be located in any symbol duration.
Table 3 shows a configuration of a subframe based on FIG. 5 .
TABLE 3
CP
Number of Samples(10 MHz)
Length
CP
m/n = CP Length/Useful OFDM Symbol Length
(Tu = 1024
Duration
Idle Per
Samples)
(Samples)
#0
#1
#2
#3
#4
#5
#6
Subframe
1/8 Tu
128
128/1024
128/1024
128/1024
124/1024
128/1024
128/1024
N/A
0
1/4 Tu
256
256/1024
256/1024
256/1024
256/1024
256/1024
256/256
N/A
0
1/16 Tu
64
64/1024
64/1024
64/1024
64/1024
64/1024
64/1024
128/256
0
1/32 Tu
32
32/1024
32/1024
32/1024
32/1024
32/1024
32/1024
64/512
0
FIG. 6 shows a subframe structure according to another embodiment of the present invention. Herein, SF k denotes a k th subframe, and S k denotes a k th OFDM symbol in a subframe.
Referring to FIG. 6 , the frame structure is the same as the subframe structure of FIG. 4 , except for an idle duration of subframe consisting of OFDM symbols having CP lengths of 1/16 Tu and 1/32 Tu. Herein, a duration corresponding to the idle duration of FIG. 4 can be used as a cyclic postfix of any OFDM symbol in the subframe. For example, the cyclic postfix may be located behind a ¼ OFDM symbol fraction of a subframe consisting of an OFDM symbol having a CP length of 1/16 Tu and a ½ OFDM symbol fraction of a subframe consisting of an OFDM symbol having a CP length of 1/32 Tu. However, the present invention is not limited thereto, and thus the duration corresponding to the idle duration may be configured with a cyclic postfix of another OFDM symbol in the subframe. In addition, although the OFDM symbol fraction is located in the 6 th symbol duration, the present invention is not limited thereto, and thus the OFDM symbol can be located in any symbol duration.
Table 4 shows a configuration of a subframe based on FIG. 6 .
TABLE 4
CP
Number of Samples(10 MHz)
Length
CP
m/n = CP Length/Useful OFDM Symbol Length
(Tu = 1024
Duration
Idle Per
Samples)
(Samples)
#0
#1
#2
#3
#4
#5
#6
Subframe
1/8 Tu
128
128/1024
128/1024
128/1024
124/1024
128/1024
128/1024
N/A
0
1/4 Tu
256
256/1024
256/1024
256/1024
256/1024
256/1024
256/256
N/A
0
1/16 Tu
64
64/1024
64/1024
64/1024
64/1024
64/1024
64/1024
64/256/64
0
1/32 Tu
32
32/1024
32/1024
32/1024
32/1024
32/1024
32/1024
32/512/32
0
FIG. 7 shows a subframe structure according to another embodiment of the present invention. Herein, SF k denotes a k th subframe, and S k denotes a k th OFDM symbol in a subframe.
Referring to FIG. 7 , the frame structure is the same as the subframe structure of FIG. 4 , except for an idle duration of subframes consisting of OFDM symbols having CP lengths of 1/16 Tu and 1/32 Tu. Herein, a plurality of OFDM symbol fractions can be deployed in the subframes consisting of OFDM symbols having CP lengths of 1/16 Tu and 1/32 Tu, so that a duration corresponding to the idle duration of FIG. 4 can be used as a CP duration of the OFDM symbol fraction. For example, the subframe consisting of an OFDM symbol having a CP length of 1/16 Tu includes 5 OFDM symbols, two ½ OFDM symbol fractions, and one ¼ OFDM symbol fraction, and the subframe consisting of an OFDM symbol having a CP length of 1/32 Tu includes 5 OFDM symbols and 3½ OFDM symbol fractions. Herein, the CP length of the OFDM symbol fraction is equal to the CP length of the OFDM symbol constituting the subframe including the OFDM symbol fraction.
Although the OFDM symbol fractions are located in 5 th , 6 th , and 7 th symbol durations in the subframe consisting of the OFDM symbols having a CP lengths of 1/16 Tu and 1/32 Tu, the present invention is not limited thereto, and thus the OFDM symbol fractions can be located in any symbol duration in the subframe.
Table 5 shows a configuration of a subframe based on FIG. 7 .
TABLE 5
CP
Number of Samples(10 MHz)
Length
CP
m/n = CP Length/Useful OFDM Symbol Length
(Tu = 1024
Duration
Idle Per
Samples)
(Samples)
#0
#1
#2
#3
#4
#5
#6
#7
Subframe
1/8 Tu
128
128/1024
128/1024
128/1024
124/1024
128/1024
128/1024
N/A
N/A
0
1/4 Tu
256
256/1024
256/1024
256/1024
256/1024
256/1024
256/256
N/A
N/A
0
1/16 Tu
64
64/1024
64/1024
64/1024
64/1024
64/1024
64/512
64/512
64/256
0
1/32 Tu
32
32/1024
32/1024
32/1024
32/1024
32/1024
32/512
32/512
32/512
0
FIG. 8 shows a subframe structure according to another embodiment of the present invention. Herein, SF k denotes a k th subframe, and S k denotes a k th OFDM symbol in a subframe.
Referring to FIG. 8 , the frame structure is the same as the subframe structure of FIG. 4 , except for an idle duration of subframes consisting of OFDM symbols having CP lengths of 1/16 Tu and 1/32 Tu. Herein, a duration corresponding to the idle duration of FIG. 4 can be further allocated as a CP duration of the OFDM symbol in the subframe. That is, the CP length can be set to 1/16 Tu+Δt and 1/32 Tu+Δt.
For example, a CP length of a subframe consisting of an OFDM symbol having a CP length of 1/16 Tu is configured with 73 samples which are increased by 9 samples from an original CP length, i.e., 64 samples, and only one CP length is configured with 74 samples. Herein, the 74 samples may be a CP length of any OFDM symbol or OFDM symbol fraction in the subframe.
The subframe consisting of the OFDM symbol having a CP length of 1/32 Tu is configured by using two methods. In a first method, 6 CP lengths are configured with 36 samples which are increased by 4 samples from an original CP length, i.e., 32 samples, and one CP length is configured with 40 samples. In a second method, 6 CP lengths are configured with 37 samples, and one CP length is configured with 34 samples. Herein, the 40 samples or the 34 samples may be a length of any OFDM symbol or OFDM symbol fraction in the subframe.
Table 6 shows a subframe configuration based on FIG. 8
TABLE 6
CP
Number of Samples(10 MHz)
Length
CP
m/n = CP Length/Useful OFDM Symbol Length
(Tu = 1024
Duration
Idle per
Samples)
(Samples)
#0
#1
#2
#3
#4
#5
#6
Subframe
1/8 Tu
128
128/1024
128/1024
128/1024
128/1024
128/1024
128/1024
N/A
0
1/4 Tu
256
256/1024
256/1024
256/1024
256/1024
256/1024
256/256
N/A
0
1/16 Tu + Δt
73 or 74
73/1024
73/1024
73/1024
73/1024
73/1024
73/1024
74/256
0
1/32 Tu + Δt
36 or 40
36/1024
36/1024
36/1024
36/1024
36/1024
36/1024
40/512
0
(Option 1)
1/32 Tu + Δt
37 or 34
37/1024
37/1024
37/1024
37/1024
37/1024
37/1024
34/512
0
(Option 2)
Although a CP length of a 6 th symbol is different from a CP length of another symbol, the present invention is not limited thereto.
Although the idle duration is included in FIG. 4 , the idle duration is used as a CP or a cyclic postfix in FIG. 5 to FIG. 8 . Accordingly, discontinuous transmission is avoided in a radio frequency (RF) side, and thus transmission efficiency can increase.
According to FIG. 4 to FIG. 8 , a subframe is configured to have the same length of the subframe consisting of the OFDM symbol having a CP length of ⅛ Tu of FIG. 3 . Therefore, mutual coexistence between subframes consisting of OFDM symbols having different CP lengths can be satisfied.
The examples of FIG. 4 to FIG. 8 are for the case where the transmission bandwidth is 10 MHz. Referring to Table 1, if the transmission bandwidth is 5 MHz, a sampling frequency is ½ times of 10 MHz, and thus one sample is two times of 10 MHz, and if the transmission bandwidth is 20 MHz, the sample frequency is two times of 10 MHz, and thus one sample is ½ times of 10 MHz. Therefore, the present invention is not limited to the transmission bandwidth of 10 MHz, and can be utilized for various transmission bandwidths.
According to the present invention, coexistence may be satisfied between frames consisting of an OFDM symbol having various CP lengths. In addition, when each subframe consists of an OFDM symbol having various CP lengths in a frame, coexistence may be satisfied between subframes.
The present invention can be implemented with hardware, software, or combination thereof. In hardware implementation, the present invention can be implemented with one of an application specific integrated circuit (ASIC), a digital signal processor (DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microprocessor, other electronic units, and combination thereof, which are designed to perform the aforementioned functions. In software implementation, the present invention can be implemented with a module for performing the aforementioned functions. Software is storable in a memory unit and executed by the processor. Various means widely known to those skilled in the art can be used as the memory unit or the processor.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The exemplary embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention. | A frame transmission method in a wireless communication system comprises setting a primary frame including a multiplicity of primary sub-frames, setting a secondary frame including a multiplicity of secondary sub-frames, and transmitting the secondary frame, wherein each of the primary sub-frames and each of the secondary sub-frames consists of multiple OFDM symbols, the OFDM symbols included in the primary sub-frame and the OFDM symbols included in the secondary sub-frame have different CP (Cyclic Prefix) lengths from one another, and the primary sub-frames and the secondary sub-frames are all equal in length. It is an advantage of the invention that frames consisting of OFDM symbols with different CP lengths can coexist together. Moreover, when each of the sub-frames within one frame consists of multiple OFDM symbols with different CP lengths, even the sub-frames can coexist together. | 7 |
RELATED APPLICATIONS
This application is a continuation of, and claims priority to: U.S. patent application Ser. No. 13/939,403, entitled “Intelligent Network Access Controller and Method,” filed Jul. 11, 2013, which is a continuation of U.S. patent application Ser. No. 13/507,675, now U.S. Pat. No. 8,509,740, entitled “Intelligent Network Access Controller and Method,” filed Jul. 19, 2012, which is a continuation of U.S. patent application Ser. No. 12/318,020, now U.S. Pat. No. 8,437,741, entitled “Intelligent Network Access Controller and Method,” filed Dec. 19, 2008; the disclosures of these three applications are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
The technical field is wireless communications.
BACKGROUND
A key performance indicator of any wireless network is coverage. In addition to providing an evolving set of features to customers, the most successful wireless networks are those that provide ubiquitous coverage and service to as broad a base of subscribers as possible. Because of the emphasis on coverage, these same networks seldom, if ever, provide methods of restricted or controlled access for targeted areas in the network. However, with heightened security concerns, and for other reasons, targeted wireless access restriction may be an important consideration, especially in a localized area, and/or for specific time periods.
SUMMARY
An intelligent network access controller for use within a targeted area or areas provides communications services across some or all relevant wireless technologies and spectrums to subscribers having wireless communications devices. The controller produces the targeted coverage area, wherein wireless access limitations may be enabled by using interfaces for receiving and sending digital messaging by the wireless communications devices; an identification module that determines an identity of a wireless communications device; an access module that receives the identity and determines an access level for the wireless communications device; and a locking module that implements logic that accepts, releases, or allows service to selected wireless communications devices to the controller based on the determined access level.
An intelligent network access controller coupled to wireless communication hardware controls wireless communications in a targeted coverage area of a local wireless network overlaying an existing wireless network. The controller controls the hardware to provoke wireless devices within the targeted coverage area of the local wireless network to attempt to register with the intelligent network access controller; receives, through the hardware, registration signals and identification information from the wireless devices; locks the wireless devices to the intelligent network access controller; determines an access category for each of the wireless devices based on the received registration signals and identification information; maintains first access category wireless devices locked to the controller while the first access category wireless devices remain in the targeted coverage area of the local wireless network; and unlocks second category wireless devices by controlling the hardware to signal the second access category wireless devices to attempt access to the existing wireless network.
DESCRIPTION OF THE DRAWINGS
The detailed description refers to the following figures in which like numerals refer to like items, and in which:
FIG. 1 is a block diagram of a wireless network incorporating an exemplary intelligent network access controller;
FIG. 2 illustrates an exemplary interface for enabling wireless access restrictions using the controller of FIG. 1 ;
FIG. 3 illustrates an exemplary interface for enabling emergency access;
FIG. 4 illustrates a single technology implementation of the controller of FIG. 1 ;
FIG. 5 illustrates a multiple technology implementation of the controller of FIG. 1 ; and
FIGS. 6A-6D illustrate an embodiment of a method for creating a local wireless network and for controlling wireless communications using the local wireless network.
DETAILED DESCRIPTION
A key performance indicator of any wireless network is coverage. The most successful wireless networks are those that have ever-expanding coverage, independent of time, to provide ubiquitous service to any and all subscribers and roaming users. Because of the emphasis on coverage, these same networks seldom, if ever, operate so as to restrict access. However, with heightened security concerns, and for other reasons, wireless access restriction may be an important consideration, especially in a localized area, and/or for specific time periods.
Current systems that impose some type of wireless access restriction function may employ jamming equipment to block wireless signals in a particular area. Other systems rely on shutdown of a cell or sector. These current wireless access restriction solutions do not discriminate among users. Instead, these solutions impose a total prohibition on wireless communications. Furthermore, these current solutions are complicated and expensive to invoke. Finally, with these current solutions, if a situation requires that certain personnel (e.g., emergency response personnel) be able to communicate using wireless communications, a secondary communications network must be established since jamming or cell shutdown prohibits all wireless communications for a given wireless technology.
In most cases jamming works across a spectrum of radio frequencies and jams the use of the entire spectrum regardless of the wireless technology or technologies deployed in the spectrum. So in the case of jamming, a localized communications network must be established on its own technology, unique devices, and spectrum further complicating the setup and operations.
Another challenge is that in most areas covered by wireless communications there are typically multiple technologies operating in a variety of spectrum ranges. Jamming solutions and cell turn down are absolute solutions that do not provide the ability to select on a device by device basis the ability to use the wireless communication within the target area.
To overcome these limitations with current art wireless communication access restriction solutions, disclosed herein is an intelligent network access controller, and accompanying method, which is shown in FIGS. 6A-6D , that either permanently or temporarily limits allowable communications on an existing wireless network to only a subset of that network's normal users. Those users not in the subset of allowable users are blocked from access to the wireless network when located in a specified area normally covered by the wireless network and/or for a specified time.
The intelligent network access controller provides, on a single platform, the necessary components for an end-to-end solution for selective communications restriction across the spectrum of wireless technology, frequency, and access methodology. In an embodiment, wireless users are classified into categories and either allowed to access the wireless networks or are prohibited access, on a subscriber-by-subscriber basis. The intelligent network access controller meets the criteria of service restriction that may be required in specific areas, while allowing selected individuals wireless communications access to wireless networks in those same areas. Thus, the intelligent network access controller eliminates the need to overlay additional communications systems to provide targeted localized wireless communications. The intelligent network access controller implements its service across both commercial as well as private wireless networks.
The intelligent network access controller is particularly useful in certain permanent facilities such as embassies, government facilities, prisons, military installations, stadiums and arenas, hospitals, public transportation facilities, landmarks, and in temporary applications including disaster recovery operations and homeland security operations. In short, the intelligent network access controller can be used in any situation or at any facility or locale to establish a controlled wireless communications environment whereby only selected individuals can access a wireless communications network.
FIG. 1 is a block diagram of a wireless communications network that incorporates an exemplary intelligent network access controller and other wireless network components to provide access restriction features. In FIG. 1 , wireless network 10 includes switching center 50 and base stations 60 , through which devices 20 establish wireless communications. Overlaying the network 10 are directional antennae 30 and repeaters 40 that operate in conjunction with intelligent network access controller (INAC) 100 , to restrict or to allow wireless communication from and to selected devices 20 . The switching center 50 includes standard components that may be found in any switching center, including a VLR and a HLR 52 , authentication center 54 , equipment identification register 56 , a mobile switching center (MSC) 57 , a packet switch 58 and a short message service center (SMSC) 59 . Ordinarily, a subscriber using a device 20 would have that device 20 registered with the network 10 once the device 20 was within the coverage area of the network 10 . However, to provide access restriction on either a temporary or a permanent basis, the INAC 100 , and associated interface 200 , which facilitates human operator interaction with the controller 100 , may be used to “lock” selected devices 20 to the INAC 100 , the method of which is shown in FIG. 6A , block 430 , and thus prevent access to the wireless network 10 .
“Locking” the wireless devices to the INAC 100 indicates that the wireless device 20 is tuned to and has been accepted by the local signal broadcast of the INAC 100 . The INAC 100 implements a mimicked signal that may follow the signal patterns, parameters, and characteristics of the underlying wireless network; however—the localized signal is only connected to the INAC 100 and not the wireless network as a whole. The end result is a wireless device that has the appearance of operating on the wireless network; however by virtue of the wireless device 20 being tuned to the local INAC 100 signal, the wireless device 20 is by default “locked” from access to the wireless network outside the coverage area of the INAC 100 .
A “device” or “wireless device” includes any wireless access mechanism including wireless handheld devices used for communications and laptop computers, personal digital assistants, or other computing device that includes wireless access technology.
A “wireless network” includes networks that provide commercial or private wireless access for voice, text, and or data access.
The INAC 100 may be implemented as an adjunct to the wireless network 10 , as an integrated feature within the wireless network, or may be implemented as a standalone device that is independent of any specific wireless network.
The INAC 100 may be implemented as software, hardware, or a combination of hardware and software. The INAC 100 may be implemented on a suitably programmable processor.
The INAC 100 includes equipment identity module 110 that receives and stores identifying information associated with devices 20 , the method of which is shown in FIG. 6B , block 443 ; access module 120 that determines, based on setup or operational mode of the INAC 100 , which of the devices 20 are to be allowed access to the wireless communications network 10 ; locking module 125 , which is used to lock a device 20 to the INAC 100 and to provide indications to the locked device 20 that make it appear that the device 20 actually is registered with the wireless network 10 ; power control module 130 , which operates in conjunction with base station 60 , RF distribution equipment 62 , amplifiers 64 directional antennae 30 and repeaters 40 to establish, per FIG. 6A , block 410 , the area subject to the access restrictions imposed by the INAC 100 ; timing module 140 , which may be used to impose temporal limitations on the access restriction functions per FIG. 6B , block 446 ; and emergency access module 150 , which operates as shown in FIG. 6D , blocks 461 - 465 , to allow certain access types (e.g., emergency 911 calls from a wireless device 20 ) while other access types remain blocked.
The INAC 100 provides, as shown in FIG. 6A , block 440 and FIG. 6B , blocks 442 - 445 , discretionary blocking of access to and from devices 20 by recognizing differences among the devices 20 . In an embodiment, the INAC 100 recognizes three categories of subscriber devices 20 : restricted, allowed, and unknown. Restricted devices are those that are identified as belonging to subscribers who are to be denied wireless access (e.g., prisoners, terrorists). Restricted devices are configured by the INAC 100 so as not to be allowed cellular service and access to the wireless network 10 . Every device 20 has a unique identifying number or characteristic, which is determined as shown in FIG. 6A , block 440 . If the device identifying number or characteristic (e.g., subscriber number) is configured to be “restricted,” the INAC 100 accepts that device's access and returns a positive acknowledgement to the device per FIG. 6C , block 452 . This creates the illusion, at the subscriber's device 20 , that the subscriber has gained access to and is operating within the wireless network 10 , when, in fact, the device 20 is locked to the INAC 100 until the device 20 is removed from the restricted access area imposed by the INAC 100 . By locking the “restricted” device 20 to the INAC 100 , all incoming and outgoing accesses by the device 20 are prevented while the “restricted” device 20 is within the restricted access area, the method of which is shown in FIG. 6C , blocks 452 and 454 .
Allowed devices are those configured in the INAC 100 as to be allowed wireless service. After determining the identity of the device 20 , and determining that the device 20 is an “allowed” device, the INAC 100 redirects the device 20 from the INAC 100 to the appropriate wireless network 10 , as shown in FIG. 6C , block 458 . This redirection forces the “allowed” device to reattempt access on the wireless network 10 . Once so redirected, the “allowed” device's subscriber can use the device 20 for normal inbound and outbound traffic. See FIG. 6A , blocks 420 , 440 , 450 , and 460 .
Unknown devices 20 are those not specifically configured by the INAC 100 as allowed or restricted. Unknown devices 20 may be configured to allow normal wireless network access depending, for example, on a security level requirement at a given location (e.g., for homeland security threat conditions of orange and lower, unknown devices are allowed access to the wireless network 10 ), as shown in FIG. 6C , blocks 454 and 456 .
The INAC 100 operates as a local overlay or underlay of the same frequency spectrum and configuration as the wireless network 10 . The area of restricted access can extend to any part of the coverage area of the wireless network 10 , and such restricted area may be enforced by the use of the power control module 130 , directional antennae 30 , and repeaters 40 . Thus, the restricted area under control of the INAC 100 may be limited to a building, a sports stadium, or a geographical area, for example. The area of restricted wireless access is not necessarily static, and can be changed based on set criteria or at the discretion of a network operator. The end result is a targeted coverage area that can provide controlled and deterministic wireless communications access by subscribers. Once a restricted, or an unknown, subscriber's device 20 leaves the restricted access area, the subscriber's device 20 re-registers with the wireless network 10 and is no longer controlled (locked) by the INAC 100 .
When the subscriber's device 20 is locked to the INAC 100 , the locking module 125 operates to ensure that the device's display and apparent operation are the same as if the device 20 were registered with the wireless network 10 . A subscriber who attempts to use a device 20 locked to the INAC 100 will see a failed access attempt, or similar warning. The subscriber's perception would likely then be that the device 20 was not receiving sufficient signal strength to enable wireless communications or the serving wireless network did not have the requisite capacity to service the access request. This further masks the purpose and operation of the INAC 100 . Only after a repeated pattern of access denial is established would the typical subscriber discern the restricted access.
The INAC 100 can be configured to provide various levels of access depending on the configuration of the subscriber devices 20 and the level of security required for the access. The INAC's operational mode may be changed dynamically, either automatically, or manually. Automatic changes may be programmed using the interface 200 . Examples of automatic changes are changes programmed into the INAC 100 based on time of day, day of week, or some other calendar-based criteria; the occurrence of a specific event (e.g., a concert); changes in threat levels (e.g., homeland security threat conditions—yellow, orange, etc.); and changes in an operational profile or physical location (of the INAC 100 or of the wireless device 20 ) (e.g., an aircraft descending below 10,000 feet, a ship entering port, a train arriving at a station). Manual changes may be implemented directly by a system operator by using the interface 200 . For any of the modes of operation, the INAC 100 provides a logging mechanism to track all system access attempts and the resulting status. Additionally the INAC 100 provides capability to view the existing database information including the allowed and restricted lists, system configuration, system statistics, and log of system activity.
The INAC's operational modes include disabled, wherein the access restrictions imposable by the INAC 100 are suspended; hold all, or virtual jam, wherein all wireless communications are processed as locked to the INAC 100 ; unknown allowed, wherein only known “restricted” devices are locked to the INAC 100 ; and unknown blocked, in which both restricted and unknown devices are locked to the INAC 100 . FIG. 2 illustrates an exemplary interface 210 produced by the interface 200 and the INAC 100 for enabling wireless access restrictions. Additionally, the INAC 100 can also operate in a passive mode where all subscriber access is redirected to the appropriate wireless network.
As subscribers access the INAC 100 , and either are locked to the INAC 100 or redirected to the wireless network 10 , the INAC 100 captures access information that can be used to generate access reports for each type of device 20 (i.e., unknown, bad, or good). The reports provide an organized analysis as to which users are accessing the system, including time period, call duration, and frequency of use. The reports also provide useful information for establishing system databases and use of the INAC 100 .
An optional feature of the INAC 100 is emergency access override to allow processing of emergency access, the method of which is shown in FIG. 6D , blocks 461 - 465 . Depending on the type of installation and the security requirements, emergency access may need to be available, and thus may be enabled or disabled. Emergency access can be configured based on each type of subscriber device; restricted, allowed, or unknown. FIG. 3 is an interface 220 that allows a system operator to enable or disable emergency access for each of the three subscriber device types (restricted, allowed, and unknown). When emergency access is enabled, per FIG. 6D , blocks 461 - 465 , the emergency access module 150 of the INAC 100 allows the subscriber's device 20 to be redirected to the wireless network 10 when that device 20 dials an emergency access number such as 911. Upon completion of the emergency access, the subscriber's device 20 returns to a locked to INAC condition, as appropriate. When emergency access is disabled, the INAC 100 ignores all call access from subscribers whose devices 20 are locked to the INAC 100 .
The INAC 100 provides for location sensitive operations, an example of which, as noted above, involves an aircraft. The INAC 100 may be installed on an aircraft so that certain devices (e.g., those of crew members) may be used for wireless communications at any time. Alternatively, the INAC 100 may be used to control access to wireless communications based on the aircraft's location (latitude, longitude, and altitude) or any aspect or aircraft operation.
The INAC 100 may include an optional security and intercept module 160 that is used for lawful intercept of wireless communications using a direct Internet connection (or other available connection type) to a monitoring station. When enabled at the INAC 100 , the security and intercept module 160 allows law enforcement personnel to monitor and record conversations and data transfers (packet and circuit), call signaling messages, accessed features, and SMS originated or terminated messages for targeted wireless devices that are currently locked to the INAC 100 and allowed localized services on the INAC 100 system.
There are many possible deployment options for the INAC 100 . For example, the INAC 100 may be implemented as a permanent part of the wireless communications network 10 . The INAC 100 also may be implemented as a standalone device that overlays one or more wireless communications networks so that all wireless communications in a specific location are capable of some form of access restriction. One example of this wireless feature is to establish an INAC 100 at a building, a facility, or a campus.
Installation of the INAC 100 as part of a network, or as a standalone device can be permanent or temporary. For example, the INAC 100 may be available as a mobile device, along with the necessary amplifiers, RF distribution, antennae and repeaters, so that a disaster recovery operation may invoke wireless access restrictions in the area where the disaster recovery is taking place. Upon completion of the disaster recovery operations, the access limitation area is disestablished.
When the INAC 100 operates to restrict wireless communications by way of a wireless network, there may still be a need to provide some form of private network communications in the wireless access limited area, the method of which is shown in FIG. 6D , blocks 466 - 468 . To provide this additional functionality, the INAC 100 may include a private network module 170 that allows for limited wireless voice communications using either a commercial technology such as GSM or CDMA, or voice over IP (VoIP) technology, including session initiated protocol/unlicensed mobile access (SIP/UMA). As additional wireless technologies become viable, these can be added to the private network solution as well. The private network module 170 also allows for connection to a PBX or PSTN.
The INAC 100 may also provide the capability to individually access the locked wireless devices overtly or covertly thus allowing the exchange of information or enabling the ability to provoke action from the wireless device.
As noted above, the INAC 100 may be used to control wireless access for one wireless technology, and/or for one frequency range, or for multiple technologies and frequency ranges. FIGS. 4 and 5 show this functionality, with examples of current wireless protocols illustrated. One skilled in the art will appreciate that other protocols would apply equally, including wireless protocols to be developed in the future. In FIG. 4 , the INAC 100 is used to create restricted wireless access area 300 as an overly to wireless network 10 , where the wireless network 10 and the restricted access area 300 are based on GSM 1800 protocols. In FIG. 5 , three wireless technologies are shown and, correspondingly, three restricted access areas ( 300 , 300 ′, 300 ″). In a further alternative, the INAC 100 may be used to create restricted access areas for only a subset of the protocols of a multi-protocol wireless network.
FIGS. 6A-6D illustrate an embodiment of a method for creating a local wireless network and for controlling wireless communications using the local wireless network. | An intelligent network access controller coupled to wireless communication hardware controls wireless communications in a targeted coverage area of a local wireless network overlaying an existing wireless network. The controller controls the hardware to provoke wireless devices within the targeted coverage area of the local wireless network to attempt to register with the intelligent network access controller; receives, through the hardware, registration signals and identification information from the wireless devices; locks the wireless devices to the intelligent network access controller; determines an access category for each of the wireless devices based on the received registration signals and identification information; maintains first access category wireless devices locked to the controller while the first access category wireless devices remain in the targeted coverage area of the local wireless network; and unlocks second category wireless devices by controlling the hardware to signal the second access category wireless devices to attempt access to the existing wireless network. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. patent application Ser. No. 09/874,656, entitled THERMAL MANAGEMENT DEVICE which was filed on Jun. 4, 2001 now U.S. Pat. No. 6,598,409, which itself claims priority to U.S. Provisional Patent Application No. 60/209,335, filed Jun. 2, 2000, both of which are incorporated herein in their entirety.
FIELD OF THE INVENTION
The present invention generally concerns a vapor compression refrigeration cycle thermal management devices and more particularly a modularized, high energy transfer rate, and gravity insensitive heat transfer device.
BACKGROUND OF THE INVENTION
More efficient and scalable thermal management systems are required in many applications ranging from electronics cooling to medical practice where localized cooling is needed as differentiated from macrocooling of a large environment.
For example, the drive for increased performance has led to smaller, faster transistors and consequently, integrated circuits with larger transistor density, higher Input/Output count, and faster clock frequency. The larger transistor density at nearly constant supply voltage and ever increasing clock frequencies has resulted in increased dynamic power dissipation. This increasing power must be dissipated by the thermal management scheme employed in the package. These trends are evidenced by the exponential increase of power density over time for state-of-the-art integrated circuits. In the latest projections of the Semiconductor Industry Association (1999), the total power dissipation is expected to push the present state-of-knowledge for thermal management. The challenge for the identification of a future thermal management technology arises from the requirement of the package to provide a robust mechanical support, a low-distortion electrical conduit for the incoming and outgoing signals, environmental protection, and thermal dissipation at low cost and high reliability.
Currently, several approaches to thermal management are used in production chip packages. For example, buoyancy-driven convective heat transfer from the heat sink to the ambient is employed for portable integrated circuit (IC) applications, while forced convection is used for high-performance IC applications. In the past, mainframe computers and supercomputers have employed complex and expensive closed-loop cooling systems using liquids. Most microprocessor and microelectronic systems have avoided closed-loop thermal management approaches due to their high cost, high power, high acoustic noise, and low reliability. These macro-scale techniques employing bulky refrigeration units are not compatible with many future microelectronic applications in high performance markets.
Efficient two-phase boiling and condensing systems capable of transferring more energy across a smaller temperature gradient can significantly help meet performance requirements for high power density and minaturized physical dimensions. Even though dropwise condensation offers heat transfer coefficients at least an order of magnitude higher than filmwise condensation, conventionally, filmwise condensation has been used in industrial condensers but not in miniaturized applications.
With the rapid advances in the area of micro-electro-mechanical systems (MEMS) in recent years, miniaturized devices are achieving higher energy effectiveness. Membranes are of particular interests in MEMS for their use as valves, pumps, and compressors in micro-fluidic devices. Membranes can use electrostatic, piezoelectric or thermal actuation to pressurize a fluid in a cavity. More recently, design concepts of miniaturized cooling systems have been proposed based on the refrigeration vapor-compression cycle (Shannon et al., 1999, and Ashraf et al., 1999). In particular, Shannon et al. (1999) have used an electrostatic diaphragm with valves to perform compression, whereas Ashraf et al. (1999) have used a centrifugal compressor. However both used conventional heat exchanger condenser and evaporator. The herein cyclic thermal management system is also based on the refrigeration vapor compression cycle, however possesses original components. In the herein system an actuated-membrane is adopted as the condensing surface as well as the ejecting device. Therefore the droplets ejected serve the dual purpose for maintaining dropwise condensation and creating a spray for highly efficient cooling.
Thus, there is a strong need for a compact, highly energy efficient device. Such a device could be connected with other similar devices to form arrays and could be incorporated in many useful devices.
SUMMARY OF THE INVENTION
These and other needs are met or exceeded by the present vapor compression cycle heat transfer device with a dropwise condenser. High efficiency cooling available in conventional large mechanical compressor vapor compression heat transfer devices is produced by the present invention in a substantially different physical embodiment similar to integrated circuit packagings, and which may be constructed using traditional and microfabrication techniques. Heating is also available from the device of the invention, since a portion of the device will expel heat into an adjacent atmosphere, fluid or object while another portion of the device will absorb heat from an adjacent atmosphere, fluid or object. Individual, self-contained devices of the invention draw little electrical power and may be interconnected with like devices to satisfy localized cooling or heating over a desired area of atmosphere, fluid or object.
A device of the invention includes a housing having integrated compressor, condenser, expansion, and evaporator structures, with the evaporator structure removing heat from an adjacent atmosphere, fluid or object and the condenser structure expelling heat into an adjacent atmosphere, fluid or object. The compressor structure includes a compressor body defining a compressor cavity and a flexible compressor diaphragm mounted in the compressor cavity that compresses refrigerant within the cavity and promotes circulation of the refrigerant through a closed path defined through the compressor, condenser, expansion, and evaporator structures.
The condenser structure is in fluid communication with the compressor structure and includes a flexible condenser diaphragm that promotes growth of a plurality of droplets to form upon a cooled condenser surface and propels the droplets from the condenser surface of the condenser diaphragm into the expansion structure. The expansion structure includes an expansion chamber in fluid communication with the condenser structure and which is in expansive receipt of the droplets propelled from the condenser diaphragm. Finally, the evaporator structure includes an evaporator chamber which is proximate a top end of the expansion chamber and which is in fluid communication with the expansion chamber and the compressor structure.
The device is modularized, energy efficient and gravity insensitive. It provides high cooling rates for electronic instruments, and offers a novel means for thermal management. It can also be scaled to accommodate different types of applications.
DETAILED DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the will become apparent upon reading the following detailed description, while referring to the attached drawings, in which:
FIG. 1 is a schematic representation of the present invention.
FIG. 2A is a schematic diagram of the vapor-compression refrigeration thermodynamic cycle followed by the present invention.
FIG. 2B is a schematic temperature-entropy diagram of the ideal vapor-compression refrigeration thermodynamic cycle followed by the present invention.
FIG. 2C is a schematic pressure-enthalpy diagram of the ideal vapor-compression refrigeration thermodynamic cycle followed by the present invention.
FIG. 3 is a schematic illustration of operation of a first embodiment of the present invention while the expansion valve is open.
FIG. 4 is a schematic illustration of operation of a second embodiment of the present invention showing a first and a second expansion valve.
FIG. 5 is a schematic illustration of operation of a third embodiment of the present invention.
FIG. 6 shows a detail view of an exemplified electrostatically actuated compressor diaphragm.
FIG. 7 shows a detail view of an exemplified electrostatically actuated compressor valve.
FIG. 8 shows a detail view of an exemplified piezoelectrically actuated compressor diaphragm.
FIG. 9 shows a detail view of an exemplified first and a second electrostatically actuated expansion valves.
FIG. 10 shows a system comprising an integrated circuit disposed on the evaporator of membrane actuated condenser/evaporator micro-cooling device, according to an embodiment of the invention.
FIG. 11 shows a personal cooling system in the form of a fabric surface having a plurality of micro-coolers attached thereto, according to another embodiment of the invention.
FIG. 12 shows a microcooler having a condenser positioned at the bottom and integrated with a gaseous fluid based heat sink, according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is more particularly described in the following examples that are intended to be illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. As used in the specification and in the claims, the singular form “a,” “an,” and “the” may include plural referents unless the context clearly dictates otherwise.
Referring now is specific detail to the drawings in which like reference numerals designate like or equivalent elements throughout the several views, and initially to FIG. 1 , the present invention is directed to a compact, integrated and self-contained vapor compression cycle heat transfer device 2 . The device 2 of the invention includes a housing 6 having integrated compressor 10 , condenser 20 , expansion 30 , and evaporator 40 structures, with the evaporator 40 structure removing heat from an adjacent atmosphere, fluid or object and the condenser 20 structure expelling heat into an adjacent atmosphere, fluid or object.
Now referring to FIG. 3 , generally, the compressor 10 structure includes a compressor body 12 defining a compressor cavity 14 and a flexible compressor diaphragm (or membrane) 16 mounted in the compressor cavity 14 that compresses refrigerant within a compressor portion 21 of the cavity 14 and promotes circulation of the refrigerant through a closed path defined through the compressor 10 , condenser 20 , expansion 30 , and evaporator 40 structures. The condenser 20 structure includes a flexible condenser diaphragm (or membrane) 22 in fluid communication with the compressor portion 21 of the compressor 10 structure. The condenser diaphragm 22 includes a cooled condenser surface 24 that promotes growth of a plurality of refrigerant droplets thereon and propels the droplets from the condenser surface 24 of the condenser diaphragm 22 into the expansion 30 structure. The expansion 30 structure includes an expansion chamber 32 in fluid communication with the condenser 20 structure and which is in expansive receipt of the droplets propelled from the condenser diaphragm 22 . Finally, the evaporator 40 structure includes an evaporator chamber 42 which is proximate a top end 34 of the expansion chamber 32 and which is in fluid communication with the expansion chamber 32 and the compressor portion 21 of the compressor 10 structure. As one will appreciate, the localized cooling and heating effect of the device 2 may be expanded via interconnection with like devices 2 .
The heat transfer device 2 of the present invention follows a vapor-compression refrigeration cycle. As illustrated in FIGS. 2A-2C , the ideal vapor-compression refrigeration cycle includes four processes:
1-2: Isentropic compression in a compressor; 2-3: Constant pressure heat rejection in a condenser; 3-4: Throttling in an expansion device; and 4-1: Constant pressure heat absorption in an evaporator.
The coefficient of performance denoted COP is defined as the ratio of the cooling load (Q L ) to the work output (W in ):
COP=Q L /W in .
The preferred embodiment is designed to produce 2-6 Watts cooling capacity while operating between 20 deg. C. and 50 deg. C. At those conditions its actual coefficient of performance (COP) will be equal to the product of the ideal COP, the isentropic efficiency of the actual compressor, and any irreversibilities due to heat transfer, which is not precisely determined but is expected to be approximately 0.8. Thus, final COP of the device 2 is predicted to be in the approximate range of 4 to 7 COP. The robustness of the device 2 will permit operation over a wide range of conditions. As an example, its efficiency should be comparable at both 10 deg. C. and 40 deg. C., while pressure and flow rates would be correspondingly lower at the lower temperature. Power consumption should be in the range of about 0.4 to 0.9 W, while weight of an individual mass produced unit should be about 20-100 grams. Obviously, this opens a broad range of applications for the device 2 of the invention due to the small size, efficient cooling, and small power demand of the unit.
The small charge required by an individual device 2 also permits refrigerants which might not otherwise be considered in conventional units from being utilized since there are fewer toxicity and flammability concerns when used in a small individual device 2 . Since the refrigerant charge of each device 2 is individual and self-contained, this concern also does not arise when many individual device 2 s of the invention are operationally combined in an array. FC-72 is a preferred refrigerant pursuant to experiments conducted to date, but others are suitable. FC-72 is highly dielectric and provides an excellent insulating fluid for interfacing with electrical device 2 s . Generally, preferred refrigerants will require low pressure lifts in the compressor, while exhibiting good thermodynamic properties. Example potential candidates include R12, R13, R13B1, R14, R21, R23, R115, R123a, R124, R134a, R141b, R142b, R143, R152a, R218, RC270, RC318, R227ea, R236ea, R245cb, R600, pentane [n-pentane], 2-methyl butane [iso-pentane], R744, RE134, RE245, RE245ca, R236fa, R1270, R116, RE1170. However, high volumetric flow refrigerants, such as water, are also suitable refrigerants.
Referring now to FIG. 3 , a first embodiment of a heat transfer device 2 in accordance with the present invention is shown. The device 2 includes a generally layered structure, including a condenser layer 20 ′ (including a flexible condenser diaphragm 22 ), a compressor layer 10 ′ (including a body 12 and a flexible compressor diaphragm 16 ), an expansion layer 30 ′ (including an expansion chamber 32 ), and an evaporator layer 40 ′(including an evaporator chamber 42 ). As noted above, operation of the device 2 is through a general vapor compression cycle with the compressor diaphragm 16 being electrically stimulated to compress refrigerant and drive refrigerant through the closed path defined within the device 2 which also includes an inlet conduit 50 and an outlet conduit 60 . The condenser diaphragm 22 is electrically stimulated to propel refrigerant that has condensed on a condenser surface 24 of the condenser diaphragm 22 into the expansion chamber 32 . Refrigerant circulates, heat is dispelled into the atmosphere by the condenser 20 on a portion of the device 2 , and is absorbed from the atmosphere by the evaporator 40 on a top side 8 of the housing 6 of the device 2 . The novel structure of the invention provides a compact, integrated, self-contained and generally modular device 2 .
As shown in FIGS. 3 and 6 , an operational cycle of the device 2 starts with the refrigerant vapor being compressed by the compressor 10 . The compression causes an increase in temperature of refrigerant fluid within the compressor cavity 14 . The compressor has a body 12 that defines the compressor cavity 14 . The body 12 may be typically formed from two connected compressor members 12 a , 12 b . The body 12 also mounts an electrically grounded compressor diaphragm 16 such that the diaphragm 16 is capable of movement within the compressor cavity 14 . A voltage applied between a pair of opposing capacitive electrical contacts 11 disposed on opposing surfaces 13 ′, 13 ″ of the compressor cavity 14 creates a capacitive force between the conductive planes defined by the compressor cavity 14 and the flexible compressor diaphragm 16 . In the illustrated embodiments, both surfaces of the compressor diaphragm 16 are conductive, while opposing portions of the outer surface 13 ′, 13 ″ of the compressor cavity 14 are conductive. Alternatives include having only one electrical contact on the outer surface 13 of the compressor cavity 14 and/or having only one conductive surface on the compressor diaphragm 16 .
In the preferred embodiment, the opposing capacitive compressor electrical contacts II include an upper compressor electrode 15 and a lower compressor electrode 17 . The compressor diaphragm 16 is adapted to selectively deflect toward the upper and lower compressor electrodes 15 , 17 . The upper and lower compressor electrodes 15 , 17 are generally integral with opposing portions of the body 12 to form an upper electrode surface 18 and a lower electrode surface 19 in the compressor cavity 14 . The compressor diaphragm 16 conforms to the respective electrode surfaces 18 , 19 when it is electrostatically driven to one or the other surface through application of a voltage to the particular electrode 15 , 17 via a voltage source for the upper compressor electrode 15 and a voltage source for the lower compressor electrode 17 . The compressor diaphragm 16 and the upper and lower electrode surfaces 18 , 19 may be coated with thin dielectric layers (not shown) for electrical insulation and protection.
In operation, the compressor diaphragm 16 is movable from a first relaxed position, to a second intake position, and to a third compressed position. In the first position, the upper and lower compressor electrodes 15 , 17 are deactivated and the compressor diaphragm 16 is in its original, relaxed, position. In the second position, the upper and lower electrodes 15 , 17 are activated with the appropriate polarization to move the compressor diaphragm 16 toward the upper compressor electrode 15 (toward the upper electrode surface 18 ) to maximize the available volume within the compressor portion 21 of the compressor cavity 14 . Finally, in the third position, the upper and lower compressor electrodes 15 , 17 are activated to move the compressor diaphragm 16 toward the lower compressor electrode 17 (toward the lower electrode surface 19 ) to minimize the volume within the compressor portion 21 of the compressor cavity 14 . The movement of the compressor diaphragm 16 from the second position to the third position compresses and transforms the refrigerant into a superheated vapor. It is contemplated that the condenser diaphragm 16 will be actuated once per refrigeration cycle.
In the present invention, the compressor diaphragm 16 may be stretched or tensile loaded, however, it is preferred that the compressor diaphragm 16 be formed in a prebuckled shape, so that, in the first position, when the compressor diaphragm 16 is in the interim position between the upper and lower compressor electrodes 15 , 17 , the buckles compress and the shape of the compressor diaphragm 16 is somewhat irregular. Upon movement toward the upper or lower electrode surface 18 , 19 , the buckled diaphragm 16 straightens out to form a smooth, uniform surface that may fully engage the respective electrode surface 18 , 19 . Buckled diaphragms have a larger volume per stroke that can be obtained with reduced actuation force when compared to stretched or tensile loaded diaphragms. Additionally, buckled diaphragms are almost stress free in both the second and third positions which results in a system that is less sensitive to temperature variations.
The body 12 may be constructed of, for example, connected layers of silicon or by molding a high temperature plastic such as ULTEM®, (registered trademark of General Electric Company, Pittsfield, Mass.), CELAZOLE®, (registered trademark of Hoechst-Celanese Corporation, Summit, N.J.), or KETRON®, (registered trademark of Polymer Corporation, Reading, Pa.). The upper and lower electrodes 15 , 17 themselves can be formed via common manufacturing methodologies such as, for example, printing, plating, sputtering, or EB deposition of metal followed by patterning by using dry film resist, as is known in the art. Low temperature organic and inorganic dielectric may also be used as an insulator between the actuating electrodes 15 , 17 .
The compressor diaphragm 16 may be made from metal coated polymers such as, for example, KAPTON® (registered trademark of E. I. du Pont de Nemours & Co., Wilmington, Del.), KALADEX®. (registered trademark of ICI Films, Wilmington, Del.) and MYLAR® (registered trademark of E. I. du Pont de Nemours & Co., Wilmington, Del.), metal, or a conductive flexibly elastic polymer that permits it to conform its surface area to the curved surfaces. Both metal and elastic polymer diaphragms can be flat or buckled. Typically, the polymeric material have elastomeric properties sufficient to permit movement between said curved surfaces. For example, fabrication of the diaphragm 16 is based upon technology developed for keyboard and flexible circuits that are produced in huge quantities making the fabrication process well optimized. Preferred diaphragms 16 are made from polymer films such as KAPTON® or MYLAR® (registered trademark of E. I. du Pont de Nemours & Co., Wilmington, Del.), or different polyesters that are commercially available.
As noted above, the closed loop formed within the device 2 also includes an inlet conduit 50 and an outlet conduit 60 . Both the inlet and outlet conduits 50 , 60 are microchannels that are in fluid communication with the compressor portion 21 of the compressor cavity 14 . The inlet conduit 50 is also in fluid communication with the evaporator chamber 42 . Further, the outlet conduit 60 is in fluid communication with the condenser diaphragm 22 of the condenser 20 . Preferably, to enhance the efficiency of the compression stroke of the compressor 10 , each conduit 50 , 60 also contains a compressor valve 70 for controlling the flow of refrigerant into and out of the compressor portion 21 of the compressor cavity 14 . The compressor valves 70 may be pressure actuated flapper valves, as known in the art, that open and close automatically due to the pumping action of the compressor 10 . It is preferred however, to electrostatically actuate the compressor valves 70 to reduce leakage or back-pressure losses.
As shown in FIGS. 3 and 7 , the inlet conduit 50 has an inlet wall surface 52 and the device 2 has a first compressor valve 70 ′ disposed within the inlet conduit 50 . Preferably, the first compressor valve 70 ′ is a hinged tab 72 ′ that has a scaling edge portion 74 ′ that is complementarily shaped to a first portion 54 of the inlet wall surface 52 . The tab 72 is hinged proximate a second portion 56 of the inlet wall surface 52 . In similar fashion, the outlet conduit 60 has an outlet wall surface 62 and the device 2 has a second compressor valve 70 ″ disposed within the outlet conduit 60 . The second compressor valve 70 ″ is a hinged tab 72 ″ which has a sealing edge portion 74 ″ that is complementarily shaped to a first portion 64 of the outlet wall surface 62 . The tab 72 ″ is hinged proximate a second portion 66 of the outlet wall surface 62 . Thus, in operation, the first compressor valve 70 ′ and the inlet wall surface 52 and the second compressor valve 70 ″ and the outlet wall surface 62 form sealable contacts when the respective sealing edge portions 74 ′, 74 ″ of the compressor valves 70 ′, 70 ″ are placed into contact with the respective first portions 54 , 64 of the inlet and outlet wall surfaces 52 , 62 to prevent refrigerant flow through the inlet conduit 50 and/or the outlet conduit 60 .
More particularly, the first compressor valve 70 ′ is movable from a closed position to an open position. In the closed position, the sealing edge 74 ′ of the first compressor valve 70 ′ is sealed to the first portion 54 of the inlet wall surface 52 to prevent flow of fluid from the evaporator chamber 42 via the inlet conduit 50 into the compressor portion 21 of the compressor cavity 14 . In the open position, the sealing edge 74 ′ of the first compressor valve 70 ′ is drawn away from the first portion 54 of the inlet wall surface 52 toward the second portion 56 of the inlet wall surface 52 (which, as noted above, is proximate the hinge of the first compressor valve 70 ′). As one will appreciate, as the sealing edge 74 ′ of the first compressor valve 70 ′ is drawn away from the first portion 54 of the inlet wall surface towards the second portion of the inlet wall surface, the inlet conduit 50 is opened which allows flow of refrigerant through the inlet conduit 50 and into the compressor portion 21 of the compressor cavity 14 .
Similarly, the second compressor valve 70 ″ is movable from a closed position to an open position. In the closed position, the sealing edge 74 ″ of the second compressor valve 70 ″ is sealed to the first portion 64 of the outlet wall surface 62 to prevent flow of fluid through the outlet conduit 60 and into the condenser 20 . In the open position, the sealing edge 74 ″ of the second compressor valve 70 ″ is drawn away from the first portion 64 of the outlet wall surface 62 toward the second portion 66 of the outlet wall surface 62 (which, as noted above, is proximate the hinge of the second compressor valve 70 ″). As the sealing edge 74 ″ of the second compressor valve 70 ″ is drawn away from the first portion 64 of the outlet wall surface 62 towards the second portion 66 of the outlet wall surface 62 , the outlet conduit 60 is opened which allows flow of refrigerant from the compressor portion 21 of the compressor cavity 14 , through the outlet conduit 60 and into the condenser 20 .
As noted above, the first and second compressor valves 70 ′, 70 ″ may comprise a hinged tab 72 ′, 72 ″ movable toward and away from the respective first and second portions 54 , 64 , 56 , 66 , of the respective inlet and outlet wall surfaces 52 , 62 . The tab 72 ′, 72 ″ is fixed at one end (i.e., hinged) in cantilever fashion with respect to the respective inlet and outlet wall surfaces 52 , 62 . The tab 72 ′, 72 ″ may be substantially rigid or, preferably, may be flexible. If the tab 72 ′, 72 ″ is flexible, it is preferred that the tab 72 ′, 72 ″ be formed from a polymeric material that has elastomeric properties. The movable tab 72 ′, 72 ″ may be formed through techniques known in the art, such as selective etching of a silicon member and/or the selective bonding of a polymer flap.
The first and second compressor valves 70 ′, 70 ″ are preferably electrostatically controlled. Electrostatically controlled valves are well known in the art. Referring generally to FIG. 8 , in this electrostatically controlled embodiment, each compressor valve 70 ′, 70 ″ further includes two opposing capacitive compressor valve electrical contacts 75 , 76 on the tab 72 ′, 72 ″ and proximate the second portions 56 , 66 of the respective inlet and outlet wall surfaces 52 , 62 . To utilize the capacitive action for the compressor valves 70 ′, 70 ″, the area about the second portions 56 , 66 of the inlet and outlet wall surfaces 52 , 62 must be made conductive, with a dielectric above the compressor valve electrical contact 76 within the inlet and outlet wall surfaces 52 , 62 . Similarly, the tab 72 ′, 72 ″ should have a conductive plane to mate with the conductive portion of the inlet and outlet wall surfaces 52 , 62 .
Preferably, the opposing capacitive compressor valve electrical contacts 75 , 76 include a movable first compressor valve electrode 77 capsulated within the tab 72 ′, 72 ″ and a fixed second compressor valve electrode 78 integral to and proximate the dielectric second portions 56 , 66 of the respective inlet and outlet wall surfaces 52 , 62 . As one will appreciate, the basic operation of the tab 72 ′, 72 ″ is simple; a voltage applied between the two compressor valve electrodes 77 , 78 establishes an electrical attraction/repulsion. Operationally, the first and second compressor valve electrodes 77 , 78 are selectively energized so that the tab 72 ′, 72 ″ is electrostatically positioned in the open or closed position. Normally, each tab 72 ′, 72 ″(and thus each compressor valve 70 ′, 70 ″) is in the closed position. Power is supplied to the respective opposing compressor valve electrical contacts 75 , 76 to provide potentials of opposite polarity in the first and second compressor valve electrodes 77 , 78 . This tends to draw the first and second compressor valve electrodes 77 , 78 toward one another, eventually moving the tab 72 ′, 72 ″ into a complete open state. When power is supplied to the respective opposing compressor valve electrical contacts 77 , 78 to provide potentials of identical polarity in the first and second compressor valve electrodes 77 , 78 , the compressor valve electrodes 77 , 78 are forced away from one another, thus forcing the tab 72 ′, 72 ″ into the closure position.
In the preferred flexible embodiment, the tab 72 ′, 72 ″ returns to the closed position under an internal, elastic force upon application of equal potential to the respective compressor valve electrodes 77 , 78 or the shorting of the compressor valve electrical contacts 75 , 76 . Thus, upon removal of the applied voltage, the inherent stress within the flexible tab 72 ′, 72 ″ curls the tab 72 ′, 72 ″ back into its original, closed, position.
Techniques for fabricating such an electrostatically driven tab 72 ′, 72 ″ are known in the art. In one example, the technique uses process and material used in the fabrication of VLSI integrated circuits. In this example five photolithographic steps are used to form the electrostatically actuated tab 72 ′, 72 ″, which, in this example, is flexible. Beginning with a silicon substrate with a polyimide insulating film, a Cr/Au/Cr metal film is deposited and pattered to form the second compressor valve electrode 78 . A polyimide film is then deposited, to insulate the second compressor valve electrode 78 from the environment. A release film of PECVD oxide is then deposited and patterned. This film is wet etched away at the end of the process to free the flexible films from the substrate. Another polyimide film is deposited to protect the bottom of the first flexible compressor valve electrode 77 from the environment and to prevent charges from being transferred from the first compressor valve electrode 77 to the second compressor valve electrode 77 in the second portion 56 , 66 of the wall surface 52 , 62 of the respective inlet and outlet conduit 50 , 60 . This film is patterned to form vias between the flexible first compressor valve electrode 77 and the second compressor valve electrode 78 for ease of wiring the device 2 . Then a second Cr/Au/Cr metal film is deposited and patterned to form the first compressor valve electrode 77 . A final polyimide film is deposited and patterned to define the size and shape of the tab 72 ′, 72 ″ as well as to protect the top surface of the first compressor valve electrode 77 from the environment. This top film may be thicker than the bottom dielectric film in order to create stress in the tab 72 ′, 72 ″ which will cause the tab 72 ′, 72 ″ to reflexively curl away to the closed position in the respective inlet and outlet conduits 50 , 60 when voltage is removed from the compressor valve electrodes 77 , 78 . The final step is to etch away the PECVD oxide with HF, which releases the flexible tab 72 ′, 72 ″ from the substrate. The fabrication steps used in this exemplified construction can be done with conventional, prior generation VLSI equipment, including contact photolithography. Further, the substrate may be, for example, silicon, metal, plastic, glass, or like materials.
In operation, when the compression process is complete, i.e., the compressor diaphragm 16 is in the third position, the second compressor valve 70 ″ is selectively opened to let the superheated refrigerant vapor to flow through the outlet conduit 60 to the condenser 20 . The first compressor valve 70 ′ remains closed to reduce back-pressure losses. When all of the compressed superheated refrigerant has escaped to the condenser 20 , the second compressor valve 70 ″ is selected closed and will remain closed through out the remainder of the refrigeration cycle. The first compressor valve 70 ′ is selected open to allow vaporized fluid from the evaporator chamber 42 to be drawn into the compressor 10 .
Referring now to FIGS. 3 and 8 , the drop-wise condenser 20 has a flexible condenser diaphragm 22 which is in fluid communication with compressed superheated refrigerant escaping the outlet conduit 60 . The flexible condenser diaphragm 22 has a condenser surface 24 which may be covered with a thin film of hydrophobic material (not shown) to promote dropwise condensation thereon the condenser surface 24 . The temperature of the condenser surface 24 is maintained at a generally constant temperature lower than the temperature of the superheated refrigerant vapor introduced via the outlet conduit 60 . The temperature difference may, for example, be approximately 1° C. to 7° C., and preferably, may be approximately 2° C. to 5° C. For example, the temperature of the saturated vapor exiting the compressor 10 may be approximately 50° C. and the temperature of the condenser surface 24 may be approximately 53° C., for a temperature difference of approximately 3° C. Once the droplets have grown to a desired size, the condenser diaphragm 22 is actuated to eject or propel the condensed droplets away from the condenser surface 24 of the condenser diaphragm 22 . As one will appreciate, the condenser diaphragm 22 will be actuated consistent with the rate of condensation of the selected refrigerant. In addition, consistent with the compressor diaphragm 16 , it is contemplated that the condenser diaphragm 22 will be actuated once per refrigeration cycle. Alternatively, it is contemplated that the condenser diaphragm 22 may be actuated at a predetermined frequency throughout the refrigeration cycle.
The condenser diaphragm 22 is connected to an electromechanical actuator 25 . A broad range of electromechanical actuators 25 which may be used with the present invention will be apparent to those skilled in the art and may utilize, for example, electrostatic, electromagnetic, piezoelectric, or magnetostrictive principles. However, preferably, the electromechanical actuator 25 is a piezoelectric actuator 25 which is operated by an electrical signal to its conductive condenser electrical contact 26 .
In the exemplified embodiment, the condenser surface 24 of the condenser diaphragm 22 forms a portion of a substantially flat bottom end 36 of the expansion chamber 32 . In a recess 38 defined within the bottom end 36 , a thin film 27 of a piezoelectric material, forming the piezoelectric actuator 25 , is seated therein and is in contact with the condenser electrical contact 26 . A base surface 23 of the condenser diaphragm 22 , which opposes the condenser surface 24 of the condenser diaphragm 22 , is connected to the piezoelectric actuator 25 . The condenser diaphragm 22 is connected to the edge area of the recess 38 so that the condenser surface 24 of the condenser diaphragm 22 is substantially planar to the bottom end 36 of the expansion chamber 32 when the condenser diaphragm 22 is in a first, unenergized, position. In this first position, the substantially planar condition of the condenser diaphragm 22 allows for the condensation of droplets on the condenser surface 24 . As one will appreciate, upon application of a pulse voltage to the condenser electrical contact 26 , the piezoelectric material 25 is actuated which forces the condenser diaphragm 22 to bow outward relative to the base surface 23 to a second position with sufficient force so that the condensed droplets of refrigerant are propelled from the condenser surface 24 toward the top end 34 of the expansion chamber 32 .
The condenser further includes a heat exchanger means for cooling the condenser surface 24 of the condenser diaphragm 22 . The heat exchanger means may comprise a heat-rejecting heat exchanger 90 that proximally bounds the condenser surface 24 . More particularly, the heat exchanger means may include a heat exchanger 90 , a fluid microchannel 92 , and a fluid pump 94 . The heat exchanger 90 may, for example, include a finned heat exchanger, such as known in the art, that is disposed on an exterior surface 9 of the housing 6 to reject heat to the surrounding atmosphere. The fluid microchannel 92 defines at least one closed flow path between the heat exchanger 90 and proximate the base surface 23 of the condenser 20 . The fluid pump 94 is disposed in the fluid channel 92 so that fluid, such as a refrigerant, is circulated therethrough the fluid channel 92 . The fluid pump 94 allows fluid that has been conductively heated by the condenser surface 24 to be drawn through the heat exchanger 90 where excess heat from the circulating fluid is rejected to the atmosphere to cool the fluid. The cooled fluid is drawn back through the microchannel 92 proximate the condenser surface 24 to cool and maintain the condenser surface 24 at the generally constant temperature. A broad range of fluid pumps which may be used with the present invention will be apparent to those skilled in the art and may utilize, for example, electrostatic, electromagnetic, piezoelectric, or magnetostrictive principles. However, preferably, the fluid pump 94 is a piezoelectric fluid pump such as, for example, the micropump disclosed in U.S. Pat. No. 5,876,187 to Forster et al., which in incorporated herein in its entirety. Alternatively, the fluid pump 94 may be an electrostatically driven diaphragm pump as described above in respect to the compressor 10 .
As one would appreciate, the expansion chamber 32 is in fluid communication with the condenser. The expansion chamber 32 has a wall surface 33 extending between the top end 34 and the bottom end 36 of the expansion chamber 32 . The wall surface 33 defines a first orifice 35 proximate the bottom end 36 of the expansion chamber 32 that serves as the outlet for the outlet conduit 60 . Further, the wall surface 33 defines a second orifice 37 proximate the top end 34 of the expansion chamber 32 that serves as the inlet for the inlet conduit 50 . As the refrigerant passes through the expansion chamber 32 , the temperature of the refrigerant undergoes a sudden drop. For example, the temperature may drop approximately 15° C. to 50° C., and, more preferably, approximately 20° C. to 40° C. Referring to FIG. 3 , at least a portion of the wall surface 33 proximate the top end 34 of the expansion chamber 32 extends outwardly away from a longitudinal axis L of the expansion chamber 32 . The top end 34 of the expansion chamber 32 has a first width that is greater than a second width of width of the expansion chamber 32 taken proximate the bottom end 36 . Thus, the cross-sectional area of the expansion chamber 32 increases as the droplets pass from the bottom end 36 to the top end 34 of the expansion chamber 32 and into the evaporator chamber 42 .
The refrigeration cycle then completes when the cooled refrigerant absorbs heat from the atmosphere or object proximate the device 2 in the evaporator 40 . The evaporator chamber 42 has a conductive member 44 that may be placed into contact with a heat generating object for which cooling is desired. In the preferred embodiment the conductive member 44 forms at least a portion of the top side 8 of the housing 6 of the device 2 . The evaporator chamber 42 is proximate the top end 34 of the expansion chamber 32 and is fluid communication with the expansion chamber 32 . The conductive member 44 has an evaporation surface 46 upon which the cooled droplets impinge after passing though the top end 34 of the expansion chamber 32 . The evaporation surface 46 may be coated with a thin film of metal (not shown) to insure that the refrigerant wets the evaporation surface 46 to provide a large heat transfer rate.
As noted, the impinged droplets provide cooling by evaporation. As the refrigerant evaporates it is returned to the compressor cavity 14 via the inlet conduit 50 . As noted above, the first compressor valve 70 ′ opens (while the second compressor valve 70 ″ remains closed) to allow the vaporized refrigerant to pass into the compressor portion 21 of the compressor 10 .
Referring now to FIGS. 4 and 9 , a second embodiment of the device 2 is shown. The construction of the second embodiment of the device 2 is similar to the first embodiment of the device 2 and, accordingly, the figures use the same reference numbers for similar components. Furthermore, the components in FIGS. 1-4 and 5 - 9 that use the same reference numbers are substantially equivalent and the description thereof is omitted for the second embodiment. In this embodiment, at least one expansion valve 100 is connected to the wall surface 33 of the expansion chamber 32 intermediate the top end 34 and the bottom end 36 of the expansion chamber 32 . The expansion valve 100 is moveable from a closed position, in which a cavity 10 bounding the condenser diaphragm 22 is defined by a portion of the wall surface 33 of the expansion chamber 32 , the expansion valve 100 , and the bottom end 36 of the expansion chamber 32 (which includes the condenser diaphragm 22 ), to an open position, in coordinated response to the activation of the condenser diaphragm 22 , to allow droplets propelled from the condenser diaphragm 22 to pass though the expansion chamber 32 and into the evaporator chamber 42 . After the droplets have passed the expansion valve 100 , the expansion valve 100 returns to the closed position. In this embodiment, the cross-sectional area of the expansion chamber 32 may increase, or preferably, may be substantially constant from the bottom end 36 through the top end 34 of the expansion chamber 32 .
While one expansion valve 100 may be used, it is preferred that a first expansion valve 100 ′ and an opposing second expansion valve 100 ″ be provided. Each of the first and second expansion valves 100 ′, 100 ″ generally is a tab 102 ′, 102 ″, having a distal end 104 ′, 104 ″, that is moveable toward and away from the wall surface 33 of the expansion chamber 32 . More particularly, the first and second expansion valves 100 ′, 100 ″ are moveable from a closed position, in which the distal ends 104 ′, 104 ″ of the first and second expansion valves 100 ′, 100 ″ are sealed to one another to define the cavity 110 bounding the condenser diaphragm 22 , to an open position, in which the distal ends 104 ′, 104 ″ of the first and second expansion valves 100 ′, 100 ″ are drawn toward opposing portions 33 ′, 33 ″ of the wall surface 33 of the expansion chamber 32 so that the condensed droplets may flow through the expansion chamber 32 .
A wide variety of applications for the invention are possible because of the improved performance provided by devices according to the invention as compared to available cooling devices. Devices according to the invention can provide ultra-high heat flux (10 3 -10 5 W/Cm 2 ) and extremely low evaporator temperature (e.g. −40 C) because of the refrigeration cycle utilized. The heat flux level provided by the invention is believed to be approaching the maximum theoretical thermodynamic limit of heat transfer. The low evaporator temperature will mitigate the stringent upper temperature limits of device component materials.
In the embodiment shown in FIG. 10 , system 1000 includes an integrated circuit 1010 , such as a microprocessor, disposed on the evaporation surface 1020 upon which the cooled droplets of membrane actuated condenser/evaporator micro-cooling device 1050 impinge. In the embodiment shown, integrated circuit 1010 and micro-cooler 1050 are separate components. The respective components of micro-cooling device 1050 can be analogous to heat transfer device 2 shown in FIG. 3 . Although a package encapsulating system 1000 is not shown, in many applications system 1000 comprising integrated circuit 1010 disposed on micro-cooler 1050 will be disposed within a package, such as a plastic package.
The high cooling level provided by micro-cooling device 1050 allows replacement of conventional heat sinks which generally comprise a solid metal slab with the integrated circuit placed on one surface of the slab and fins on the other surface of the slab to increase heat transfer. Moreover, the high heat flux provided by invention can permit integrated circuit 1010 to run at higher operating currents than are otherwise possible to achieve higher speeds, without impermissibly raising the junction temperature of the integrated circuit 1010 .
System 1000 can be fully integrated where the micro-cooler 1050 is fabricated on the same substrate (e.g. Si) as integrated circuit 1010 . In this embodiment, integrated circuit 1010 also utilizes evaporation surface 1020 of micro-cooler 1050 as a portion thereof. For the fully integrated embodiment of system 1000 , refrigerant for micro-cooler 1050 is generally filled prior to sealing the device.
The invention can be used for cooling high heat flux applications (10 2 -10 3 W/cm 2 ), such as generated by electronic components and related systems. For example, the invention can be used to provide high heat flux localized cooling for on board avionics, supercomputers, desktops, laptops, digital assistants, and cell phones.
The invention can also be used for local cooling of hot spots in a variety of macro devices and systems. For example, particle accelerators, turbine blades, laser weapons, radar systems, and rocket nozzles can utilize the invention. In macro applications, an array comprising a plurality of micro-coolers is generally utilized. This arrangement offers flexibility and increased reliability as the failure of a single micro-cooler in the array will not significantly diminish the overall cooling provided by array.
As shown in FIG. 11 , the array concept is shown with reference to a personal cooling system 1100 comprising a plurality of micro-coolers 1110 attached to a fabric surface 1120 , according to another embodiment of the invention. In this embodiment, the evaporator surface (not shown) of micro-coolers 1110 are disposed on fabric surface 1120 , such as secured with a thermally conductive glue or tape. The fabric should be thin and strong to minimize the heat transfer resistance. It also should be selected to provide a reasonably high thermal conductivity, at least in regions where micro-coolers 1110 are disposed. Fabric can include a plurality of intermixed thermally conductive particles, such as where micro-coolers are located, to increase thermal conductivity thereof. Personal cooling system can be used for soldiers and for other outdoor activities. In an analogous arrangement, the invention can also be used with refrigeration bags.
The system can be used as a heating unit by attaching one or more microheaters to micro-scale heating bags or heating blankets for biomedical fluids and organs by reversing the refrigerant flow as in a conventional heat pump. In this mode, compressed refrigerant vapor is directed first to the surface to be heated.
The invention can be used as device which provides both heating and cooling. To permit cycling of the device between a refrigeration cycle to a heating cycle, analogous to a conventional heat pump, a controller and a reversing valve can be added to reverse the direction of the cycle when directed to by the controller, such as based on predetermined temperature limits.
FIG. 12 shows a micro-cooler system 1200 comprising a micro-cooler 1250 and a gaseous working fluid 1218 based heat sink 1225 , according to another embodiment of the invention. Gaseous working fluid based heat sink 1225 helps extend the life of micro-cooler 1250 as compared to liquid based heat sinks, since the gaseous working fluid 1218 minimizes induced stress and wear on the condenser diaphragm 1210 (e.g. a piezoelectric) when vibrating. The gaseous working fluid can comprise air, or more preferably gases having higher thermal conductivities, such as N 2 or H 2 . The gaseous working fluid can be held at a vacuum level to optimize heat transfer.
Micro-cooler 1250 is built from a silicon or other similar substrate 1235 and includes compressor 1221 and evaporator 1230 . Condenser diaphragm 1210 of micro-cooler 1250 is positioned at the bottom of FIG. 12 and is and integrated with a gold layer 1220 of heat sink 1225 . Device 1250 includes thermally insulating coating layer 1260 . Heat sink 1225 includes membranes 1228 and 1229 . Membranes 1228 and 1229 vibrate up and down and preferably operate 180 degrees out of phase to create an oscillatory motion of the gaseous working fluid 118 as shown in FIG. 12 .
Heat sink 1225 provides convective cooling by oscillatory gaseous motion of the working fluid 1218 combined with micro fins 1215 and conventional fins 1238 which surround the volume encapsulating working fluid 1218 . Micro fins 1215 provide a ripple interface 1241 that induces microcirculation of the working fluid 1218 to enhance heat transfer. This arrangement provides an enhanced rate of cooling for the condenser 1210 and micro-cooler 1250 .
In operation of system 1200 , vapor within the micro-cooler 1250 refrigeration loop condenses at condenser diaphragm 1210 having a temperature T Vapor and pressure P Vapor . Gaseous working fluid 1218 in heat sink 1225 is at P Coolant and T Coolant , where T Coolant is significantly below T Vapor , such as 30 C Heat is transferred from condenser diaphragm 1210 to gold film 1220 and then to working fluid 1218 and out to an ambient surrounding fins 1215 and 1238 .
It is preferred that the each expansion valve 100 ′, 100 ″ be an electrostatically drive valve similar in operation and construction to the electrostatically driven first and second compressor valves 70 ′, 70 ″ discussed above. In this preferred embodiment, each expansion valve 100 ′, 100 ″ includes opposing capacitive expansion valve electrical contacts 105 , 106 on the tab 102 ′, 102 ″ and a portion of the wall surface 33 ′, 33 ″ of the expansion chamber 32 which are adapted to selectively move one of the respective first and second expansion valves 100 ′, 100 ″. As one will appreciate, the opposing capacitive expansion valve electrical contacts 105 , 106 for each of the first and second expansion valves 100 ′, 100 ″ comprise a first expansion valve electrode 107 encapsulated within the tab 102 ′, 102 ″ and a second expansion valve electrode 108 proximate the wall surface 33 of the expansion chamber 32 . Preferably, the second expansion valve electrode 108 is integral with the body 12 . Upon selective application of a voltage of desired polarity, the first and second expansion valve electrodes 107 , 108 can be selectively energized so that the respective tabs 102 ′, 102 ″ are electrostatically positioned in the open or closed position. The tab 102 ′, 102 ″ may be substantially rigid, however, it is preferred that the tab 102 ′, 102 ″ is formed from a polymeric material having elastomeric properties.
Referring to FIG. 5 , a third embodiment of the device 2 is shown. The construction of the third embodiment of the device 2 is similar to the first and second embodiments of the device 2 and, accordingly, the figures use the same reference numbers for similar components. Furthermore, the components in FIGS. 1-9 that use the same reference numbers are substantially equivalent and the description thereof is omitted for the third embodiment. One skilled in the art will appreciate that the general structures of the compressor 10 , the condenser 20 , the expansion chamber 32 , and the evaporator 40 are similar to the first and second embodiments described above. However, in this exemplified embodiment, the compressor 10 and the condenser 20 are formed within the same layer. This illustrates that many permutations of the layered approach to constructing the device 2 of the invention are possible and are contemplated.
Electrical vias provide electrical connections with the electromechanical actuator 25 of the condenser 20 , and leads connect vias to the first and second compressor valves 70 ′, 70 ″ in the preferred electrostatically clamped compressor valve embodiment. Additional leads provide electrical connection to the compressor electrodes 15 , 17 in the compressor cavity 14 , preferably formed as multiple separate electrodes to encourage a zip action in the compressor 10 as it compresses. Still further leads connect vias and provide electrical connection to the expansion valve 100 in the electrostatically clamped expansion valve embodiment. Solder bumps in one layer oppose vias in another layer to provide electrical connections between layers in a manner commonly used to connect printed circuit board (PCB) layers. Outside control circuitry may be used to control compressor 10 , condenser 20 , compressor valve 70 , and expansion valve 100 actions, or an on board chip may be included.
Efficient operation of the device 2 requires thermal isolation between hot and cool areas of the device 2 . Isolation between the condenser and the compressor may be provided by the insertion of an insulator 120 between the relative hot and cold portions of the device 2 . The insulator 120 can also serve as a portion of the electrical connection to outside power sources through electrical connection network.
The device 2 of the invention is fabricated according to a combination of macro and microfabrication techniques. Low end dimensions in the device 2 of the invention are realizable through microfabrication techniques, while higher dimension features may be achieved via low pressure injection molding techniques. Two construction approaches, however, are preferred (microfabrication, injection molding). The application (cross sectional area, refrigerant choice, operation pressure) may drive the final choice of fabrication methods. The preferred method of fabricating the invention employs a layered approach, or an approach similar to laminate manufacturing, in order to provide a robust method for high volume production. Individual components of the device 2 are partially or wholly fabricated in layers, and then are assembled and bonded together. Components are aligned to communicate electrically and to communicate refrigerant fluid with other components.
For use of the invention over long time periods, refrigerants under pressure may eventually be lost to the surroundings due to the permeability of the material and the subsequent diffusion of the high pressure gases through the polymer walls. The rate of loss varies greatly between different polymers and refrigerants. Small molecule refrigerants tend to diffuse more rapidly through solid polymers than those comprised of larger molecules. Different polymers are also more or less permeable to molecules of various chemistries. Long term loss is exacerbated since the invention employs relatively large surface areas, compared to the total amount of refrigerant charge used. A diffusion or vapor barrier comprised of a thin film of metal may be added between the layers and/or on exterior surface of the housing to reduce the potential for diffusion. If the metal vapor layer is on the surface, a thin polymer coating can be placed over it to protect it from wear.
Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiment, and the various other changes and modifications may be affected therein by one skilled in the art without departing from the scope of spirt of the disclosure. All such changes and modifications are intended to be included within the scope of the disclosure as defined by the appended claims. | An actively cooled system includes a heat generating device and at least one heat transfer device. The heat transfer device includes a refrigerant loop including a compressor for providing a superheated vapor state from a vapor stream, a condenser comprising a membrane coupled to an actuator, the condenser including a condensing surface for condensing the superheated vapor into a plurality of droplets, and an evaporator for receiving the droplets. An expansion structure is interposed between the condenser and the evaporator, wherein the membrane ejects the plurality of droplets toward the evaporator during refrigerant cycle intervals when the expansion structure is open. At least a portion of the heat generating device is in thermal contact with the evaporator. | 5 |
FIELD OF THE INVENTION
THIS INVENTION relates to a method and apparatus for filling containers, such as syringes and cartridges, with flowable materials and, more particularly, high viscosity materials, such as solder paste, adhesives and lubricants.
BACKGROUND OF THE INVENTION
Syringes and cartridges for containing such high viscosity flowable materials are formed with a dispensing nozzle at one end and a larger aperture at the other end. In known filling systems, the dispensing nozzle is blocked or sealed whilst the syringe or cartridge is filled through the larger aperture. The filled syringe or cartridge is then sealed by a stopper which is pushed into the larger aperture. To discharge the contents of the syringe, the dispensing nozzle is either unblocked, or the seal broken, and the stopper is pushed into the syringe or cartridge displacing the material in the syringe or cartridge through the dispensing nozzle.
Such known filling systems for filling syringes or cartridges with high viscosity materials require the use of a high pressure pumping system. The high viscosity materials are introduced into the syringe or cartridge through the larger aperture thereof--i.e. not through the dispensing nozzle--and then a stopper is inserted in the end of the syringe or cartridge to prevent air coming into contact with the material within the syringe or cartridge.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the problems associated with known filling systems and, accordingly, one aspect of the present invention provides an apparatus for filling a syringe or cartridge comprising: a reservoir for holding a flowable filling material; a plunger associated with the reservoir to exert pressure on the flowable filling material in the reservoir, which plunger includes at least one dispensing port defining a channel through the plunger for connection with a syringe or cartridge to be filled; and means for applying pressure to the plunger.
A further aspect of the present invention provides a method of filling a syringe or cartridge with a flowable filling material from a reservoir, comprising the steps of:
locating a nozzle of an empty syringe or cartridge in a dispensing port of a plunger associated with the reservoir; and
applying pressure to the plunger to force filling material from the reservoir through the dispensing port and into the syringe or cartridge through the nozzle.
In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an end view of an apparatus embodying the present invention for filling containers with high viscosity flowable material;
FIG. 2 is a side view of the apparatus of FIG. 1; and
FIG. 3 is a plan view of the apparatus of FIG. 1.
DESCRIPTION OF THE INVENTION
Referring to FIGS. 1, 2 and 3, an apparatus embodying the present invention comprises a filling system 1 which is positioned on a bench platform 2 so that the working parts of the filling system 1 are at an appropriate height for operation, maintenance and service.
The filling system 1 comprises a filling material reservoir 3 which is formed as a stainless steel cylindrical vessel 3 having a closed bottom end 4 and an open top end 5. The vessel 3 is filled with a flowable material which is to be loaded into syringes, cartridges or the like. The open top end 5 of the vessel 3 is sealed by a circular plunger 6. The plunger 6 is accurately sized to provide a hermetic seal with an inner surface 7 of the vessel 3 to ensure that no air can come into contact with the material in the vessel 3. Preferably, O-rings (not shown) are used to ensure an appropriate hermetic seal between the plunger 6 and the vessel 3.
The plunger 6 is provided with an air release valve (not shown) which can be opened to allow any air situated between the material in the vessel 3 and the plunger 6 to be evacuated as the plunger 6 is lowered down to the level of the material within the vessel 3. Once the plunger 6 abuts the material within the vessel 3 and some of the material is forced out through the air release valve, the air release valve is closed. Thus, the plunger 6 is seated directly on the material in the vessel 3, there being no air left in the vessel 3.
The plunger 6 is formed with one or more dispensing ports 8. The or each dispensing port 8 forms a channel between the material in the vessel 3 and a syringe 9 or cartridge 10 to be connected to the or each dispensing port 8.
Each dispensing port 8 is sized to receive a dispensing nozzle 11 of a syringe 9 or cartridge 10.
In the embodiment shown in FIGS. 1, 2 and 3, three separate vessels 3 are located along the bench platform 2. An A-frame 12 is fixed to the bench platform 2 and provides a support frame over the vessels 3. The apex of the A-frame supports three separate pneumatic cylinders 13 each having a piston 14 which projects from its cylinder 13 downwardly towards a respective vessel 3. Each piston 14 is fixed to the centre of the plunger 6 of a respective one of the vessels 3.
Actuation of a cylinder 13 thereby provides movement of the associated plunger 6. Preferably, the pneumatic cylinders 18 are operated by compressed air supplied by an air compressor and the pressure applied by the cylinders 13 to the plungers 6 is controllable in dependence on the viscosity of the material within the vessels 3.
Each syringe 9 or cartridge 10, when empty, is provided with a stopper 15 which is located in the syringe 9 or cartridge 10 immediately adjacent the dispensing nozzle 11 thereof.
A stainless steel stop ring 16 is placed on top of each stopper 15.
An end stop sensor 17 is mounted, preferably, on the piston 14. The end stop sensor 17 is operable to detect the presence of the stainless steel stop ring 16 on top of the stopper 15.
In operation, the plunger 6 is seated directly on top of the material in the vessel 3 and the air release valve is closed. The dispensing nozzle 11 of a syringe 9 or cartridge 10 is inserted into a dispensing port 8 in a plunger 6. The nozzle 11 is hermetically sealed with respect to the dispensing port 8. The pneumatic cylinder 13 linked to the plunger 6 is actuated to cause pressure to be applied to the plunger 6 by the piston 14. The plunger 6 thereby increases the pressure on the material within the vessel 3 forcing the material up through the dispensing port 8 and through the dispensing nozzle 11 into the syringe 9 or cartridge 10.
As the material is forced into the syringe 9 or cartridge 10 through the nozzle 11, the stopper 15 is forced upwardly in the syringe 9 or cartridge 10 as the volume of material in the syringe 9 or cartridge 10 increases. The stainless steel stop ring 16 thereby moves up the syringe 9 or cartridge 10 with the stopper 15 as the syringe 9 or cartridge 10 is filled. The stainless steel stop ring 16 eventually comes into contact with the end stop sensor 17 which detects the presence of the stainless steel stop 16 ring by, for example, the stainless steel stop ring 16 completing an electric circuit with the sensor 17. This indicates that the syringe 9 or cartridge 10 is full and a signal is sent to stop pressure being applied by the pneumatic cylinder 13 to the plunger 6. The height of the end stop sensor may be varied so that the syringe or cartridge is filled to a selected volume.
The filled syringes 9 or cartridges 10 are then detached from the dispensing ports 8 for subsequent usage.
When the supply of filling material in a container 3 has been exhausted, the plunger 6 may be lifted back up the vessel 3 with the air release valve opened to ensure that no material in partly filled syringes 9 or cartridges 10 is sucked backwards into the vessel 3 by the reduced pressure in the container 3 caused by the movement of the plunger 6 up the vessel 3.
Preferably, as shown in the left hand side and middle filling systems of FIGS. 2 and 3, the sensor 17 is provided on the piston 14, although different embodiments are possible whereby the sensor 17 is mounted on the top of the syringe 9 or cartridge 10 to contact the stainless steel stop ring 16 as it rises within the syringe 9 or cartridge 10.
The plan view of FIG. 3 shows how the configuration of dispensing ports 8 on a plunger 6 may be adapted to accommodate different sizes and numbers of syringes 9 or cartridges 10 which are to be filled. The plungers 6 in the left hand side and middle filling systems of FIGS. 2 and 3 can each accommodate two cartridges 10, whilst the right hand side filling system can accommodate eight syringes 9 using an array of dispensing ports 8 located around the centre of the plunger 6.
As previously mentioned, the pressure required to fill a syringe or cartridge with a high viscosity flowable material using embodiments of the present invention is dependent upon the viscosity of the filling material. In the case of a solder paste having a viscosity of 1100 kcPs, the pressure required to be exerted on the plunger 6 is in the region of 110 psi (758 kN/m 2 ).
The above described apparatus and method is particularly useful for filling syringes 9 or cartridges 10 or the like with high viscosity flowable materials such as solder paste, adhesives, lubricants etc.
It is envisaged that the plurality of vessels 3 shown in FIGS. 2 and 3 may be replaced by a single supply tank constituting a reservoir for the filling material. The single tank has a number, three in the present example, of upwardly extending cylindrical sleeves each for receiving a respective plunger 6.
The features disclosed in the foregoing description in the following claims and/or in the accompanying drawings may, both separately and in combination thereof, be material for realising the invention in diverse forms thereof. | A syringe or cartridge has a displaceable stopper located herein, and an apparatus for filling the syringe or cartridge has a reservoir for holding a flowable filling material and a plunger associated with the reservoir to exert pressure on the flowable material in the reservoir. The plunger includes at least one dispensing port defining a channel through the plunger for connection with the syringe or cartridge to be filled. The apparatus also has a pressurizer for applying pressure to the plunger. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 61/135,448 filed on Jul. 19, 2008, and entitled “Molding cycle enhancer”. The entire contents of the foregoing application are hereby incorporated by reference.
FIELD OF INVENTION
[0002] The present invention generally relates to blow molding plastics, more particularly, to systems, methods, and devices for forming, curing, and cooling blow molded plastics.
BACKGROUND OF THE INVENTION
[0003] Blow molding is a plastic manufacturing process where a molten plastic, also called a parison, is placed in a mold and contacted with a compressed fluid, such that the parison is forced and/or stretched to conform to the mold when it is subjected to a pressure from the compressed fluid. These systems may be used to make a wide variety of plastic products, such as, milk jugs, carbonated beverage bottles, water bottles, watering cans, plastic storage cases, and the like. Blow molded products generally have hollow cavities enclosed within plastic structures, making blow molding an efficient process to produce large volumes of low cost plastic products. Once a blow molding process and system have been designed and built, the ability to decrease the cycle time, that is the time it takes to make a part or lot of parts, makes the blow molding process more efficient and economical.
[0004] Typical blow molding systems include a blow stem coupled to a fluid supply, where the fluid supply is usually compressed air at room temperature. The system also includes a melted plastic supply configured to supply a parison to a mold. The mold is generally configured to couple with the blow stem, such that, the fluid supply provided through the blow stem may be applied to the parison to force or stretch the parison to conform to the interior dimensions of the mold.
[0005] Typical blow mold systems also include an external mold cooler, such as a bath that provides water to the exterior of the mold, or to internal plumbing that circulates water through the structure of the mold to provide cooling. Generally, after the parison has been stretched or forced to conform to the mold, the parison must cool and harden to retain the shape of the mold. Cooling and hardening of the parison requires that the blow mold system maintain a pressure within the cavity created in the parison by the compressed air, such that the parison continues to conform to the mold until it is sufficiently cool and hard to retain the physical structure of the mold.
[0006] These systems present challenges to blow mold plastic manufactures. Specifically, the manufacture must wait for the plastic to cure before removing the formed plastic part from the mold and making another plastic part. Although cure time varies depending on the plastic product being formed, a typical blow mold system that manufactures milk jugs (a approximately one gallon container) can require between, approximately 6.5 seconds and 8.0 seconds to allow the formed parison to cool and harden sufficiently to be removed from the mold. A typical blow mold system that manufactures bleach bottles (an approximately one gallon container) can require between, approximately 14 seconds and 18 seconds to allow the formed parison to cool and harden sufficiently to be removed from the mold. This time spent waiting for cooling slows down the process and is inefficient. As such, there is a need to reduce the cooling time for solidifying blow molded products.
SUMMARY OF THE INVENTION
[0007] The systems, methods, and devices discussed herein in exemplary embodiments of the present invention provide a circulating cooling fluid to the internal cavity of the formed parison such that the formed parison may cool and harden sufficiently to be removed from the tool, in a time that is shorter than the time for a comparable product made without the disclosure of this application. As such, the present invention provides advantages over prior art blow molding systems.
[0008] In various embodiments, a device for facilitating internal cooling within a mold during blow molding operations comprises a blow stem and a supply port forming part of the blow stem. The supply port is configured to supply fluid to the mold. The device further comprises an exhaust port forming part of the blow stem. The exhaust port is configured to exhaust fluid from the mold.
[0009] In various embodiments, a plastic molding system comprises a fluid supply, a fluid exhaust, and a bidirectional blow stem. The bidirectional blow stem is configured to receive a fluid from the fluid supply and supply fluid to a parison to inflate the parison. The bidirectional blow stem is also configured to exhaust fluid from the parison to the fluid exhaust during cooling of the parison.
[0010] In various embodiments a method of making blow molded plastics, comprises the steps of supplying a parison to a mold, supplying a blow stem with pressurized air, and forcing the parison to conform to the mold. Once the parison has conformed to the mold, the parison is allowed to stabilize within the mold. Then a cooling airflow is created within the mold to cool and cure the parison and cool the mold. Once the parison is cured the cured parison (blow molded plastic part) is removed from the mold.
[0011] One object of the present invention is to decrease cycle time for manufacturing blow molded plastic products. The systems, devices, and methods disclosed herein enable a decrease in cycle time of at least one second. The decrease in cycle time is provided by the introduction of a cooling air flow to the internal cavity of a blow molded parison. As those skilled in the art will appreciate, the volume of the internal cavity of the blow molded parison effects the decrease in cycle time of the devices, systems, and methods disclosed herein. In particular, the devices, systems and methods disclosed will provide decreased cycle times, between, approximately 10 percent and 35 percent. Various factors dictate the overall decrease in cycle time achieved by the disclosed devices, systems, and methods, including but not limited to, for example, the temperature of the parison, temperature of the supply air, wall thickness of the plastic part being formed, the geometry of the blow molded plastic part, the internal volume of the blow molded parison, the number, size, configuration, and shape of the blow stem(s), flow rate of the cooling fluid flow, the controls in use, the ambient conditions, and/or the like. In one embodiment, the cycle time for blow molding a thin walled one gallon plastic container is decreased by approximately 20 percent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the Figures, wherein like reference numbers refer to similar elements throughout the Figures, and:
[0013] FIG. 1 illustrates an exemplary block diagram of a blow mold system in accordance with an exemplary embodiment; and;
[0014] FIG. 2 illustrates a side-view cross section of an exemplary blow stem in accordance with another exemplary embodiment;
[0015] FIG. 3 illustrates a top-view cross section of an exemplary blow stem in accordance with another exemplary embodiment;
[0016] FIG. 4 illustrates an exemplary schematic of a blow mold system in accordance with another exemplary embodiment;
[0017] FIG. 5 illustrates another exemplary schematic of a blow mold system in accordance with another exemplary embodiment;
[0018] FIG. 6 illustrates yet another exemplary schematic of a blow mold system in accordance with another exemplary embodiment; and
[0019] FIG. 7 illustrates a block diagram of an exemplary method of blow molding.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0020] The following is a description of exemplary embodiments of the invention only, and is not intended to limit the scope or applicability of the invention in any way. Rather, the following description is intended to provide convenient illustrations for implementing various exemplary embodiments of the invention. As will become apparent, various changes may be made to methods, structures, topologies, and compositions described in these exemplary embodiments without departing from the spirit and scope of the invention.
[0021] In general, systems, methods, and devices are suitably configured to facilitate the production of blow molded plastics. The production may provide for the rapid manufacture of plastic products with hollow internal cavities. Production of blow molded plastics may be facilitated, for example, through use of blow molding and/or blow forming, and in particular though extrusion blow molding, injection blow molding, stretch blow molding and/or the like, such that the production results in a finished plastic part.
[0022] For example, the device and/or system may be configured to provide a supply of compressed fluid to a parison such that the parison is forced and/or stretched to conform to a mold. Further, the device and/or system may be configured to exhaust the pressurized fluid from the internal cavity of the parison, while supplying a cooling fluid flow, such that a sufficient internal pressure is maintained to retain the shape of the parison in the mold. The cooling fluid flow may provide convective cooling and/or conductive cooling. This “internal” cooling, in addition to any other cooling that may be used, facilitates faster production of plastic parts compared to processes that do not use internal cooling processes. Once the parison has been sufficiently cooled, the system is configured to expel the plastic part from the mold. Consequently, the production devices, systems, and methods described herein may provide for reduced costs in the manufacture of blow-molded plastics and/or provide for higher production yields of blow molded plastics parts.
[0023] Although described herein in the context of blow molded plastics, it should be understood that the techniques described herein may work in other contexts and that the description herein related to blow molded plastics may be similarly applicable to any manufactured product and or system, wherein the product produced has internal cavity formed by contacting the raw material with a compressed fluid such that the raw material is forced and/or stretched to conform to a mold and cooled to cure, in order to retain the shape of the mold.
[0024] Blow mold systems exist in various configurations, with a variety of components and performance factors. Nevertheless, an exemplary blow mold system is briefly described here. An exemplary blow mold system may comprise one or more blow stems coupled to a fluid chamber. The fluid chamber may be coupled to a fluid inlet and a fluid outlet. The fluid inlet may be coupled to a compressed fluid supply and a controller, such that the compressed fluid supply is capable of providing a supply of compressed fluid to the fluid chamber in accordance with instructions from the controller. The fluid outlet may be coupled to a control module. The control module may also be coupled to a controller, such that the controller is configured to modulate the fluid outlet. Finally, an exemplary blow mold system may comprise a mold operatively coupled to the blow stem and configured to receive a parison.
[0025] Referring to FIG. 1 , and in accordance with an exemplary embodiment, a blow molding system 100 may comprise a blow stem 110 . Blow molding system 100 may further comprise a mold 160 . Mold 160 may be in fluid communication with blow stem 110 .
[0026] Blow stem 110 may be any structure comprising a supply port and an exhaust port. In various exemplary embodiments, blow stem 110 may be, for example, a blow pin, a blow stem, a blow needle, a stretch pin, and/or the like. In an exemplary embodiment, blow stem 110 is a bidirectional blow stem. As such, the bidirectional blow stem allows for airflow in at least two directions. Blow stem 110 may be a pair of pipes, tubes, and/or similar structures. Blow stem 110 may be configured to conduct a fluid from a fluid supply through a supply port to a mold. Further, blow stem 110 may be configured to exhaust a fluid from a mold through an exhaust port to a fluid outlet.
[0027] Referring to FIGS. 2 and 3 , and in one exemplary embodiment, blow stem 110 may comprise a flange 220 , one or more exhaust ports 210 , and one or more supply ports 200 . Flange 220 may be an annular structure coupled to supply port 200 and configured with one or more exhaust ports 210 . In one exemplary embodiment, flange 220 may be configured with any number of exhaust ports 210 , for example, one to twelve exhaust ports 210 . In one exemplary embodiment, flange 220 may comprise an attachment system, such as a thread, a set screw mechanism, a detent mechanism, a press fit configuration, a configuration suitable for applying a weld, braze, adhesive, and/or the like, and/or similar mechanical, electro-mechanical, and/or chemical attachment systems. The attachment system of flange 220 may be configured to allow blow stem 110 to be removably coupled to a fluid supply. Supply port 200 may be a nozzle, tube, and/or similar structure. Supply port 200 may be in fluid communication with a fluid supply and conduct the fluid supply to mold 160 containing a parison. Stated another way, supply port 200 may be configured to supply a fluid supply to inflate the parison with the mold. Exhaust port 210 may be a through hole, passage, channel, and/or the like. Exhaust port 220 may be configured to exhaust and conduct a fluid from mold 160 to a fluid outlet.
[0028] Referring again to FIG. 1 , and in accordance with various exemplary embodiments, mold 160 is any structure with an internal cavity having an internal geometry conforming to the exterior of a part to be manufactured. Mold 160 may be in fluid communication with blow stem 110 and configured to receive a parison. As such, compressed fluid supplied through blow stem 110 stretches and/or forces the parison to conform to the internal cavity of mold 160 . In an embodiment, mold 160 may have an internal cavity that defines the exterior shape of a plastic part to be blow molded. As such, the internal cavity may take the shape of any plastic part capable of being blow molded, such as, for example, a milk jug, a carbonated beverage bottle, a watering can, a storage container, and/or the like. In an embodiment, mold 160 may be in fluid communication with one or more blow stems 110 . Mold 160 may be configured with a cooling system. The cooling system may be a channel contained between the internal cavity and the exterior surface, such that the channel may be configured to transport cooling fluid through the mold. The cooling system may also be a fluid bath, such that the exterior surface of the mold is bathed in a cooling fluid to provide conductive and/or convective cooling.
[0029] In accordance with various exemplary embodiments, blow molding system 100 may further comprise a fluid inlet 140 , and a fluid outlet 150 . Fluid inlet 140 may be any structure suitable for supplying a fluid. Fluid inlet 140 may be, for example, a pipe, a tube, a hose, a conduit, a coupling, a fitting, a valve, and/or the like. Fluid outlet 150 may be any structure suitable for exhausting a fluid. Fluid outlet 150 may be, for example, a pipe, a tube, a hose, a conduit, a coupling, a fitting, a valve, and/or the like. The fluid may be any gas and/or liquid suitable for use in a system for blow molding plastics, such as, for example, air, nitrogen, water, and/or the like. In an exemplary embodiment, the fluid supplied to fluid inlet 150 is air. Although described hereinafter as air, it should be understood that this description is also applicable to other gases and fluids. Fluid inlet 140 may be in fluid communication with blow stem 110 at supply port 200 . In one exemplary embodiment, fluid inlet 140 may be configured to supply air to supply port 200 , such that, the supply stretches and/or forces a parison to conform to mold 160 . In various embodiments, fluid inlet 140 may be configured to supply compressed air at a temperature of between, approximately 65 degrees Fahrenheit and 260 degrees Fahrenheit, where the temperature range provided, is the temperature range of the fluid prior to the air contacting the parison. Moreover, in various embodiments, the temperature of the air supplied to fluid inlet 140 may be any temperature suitable for cooling in parison. Fluid outlet 150 may be in fluid communication with blow stem 110 at exhaust port 210 . In one exemplary embodiment, fluid outlet 150 may be configured to exhaust air through exhaust port 210 , wherein, a cooling airflow is created within the parison, where the parison has conformed to mold 160 .
[0030] Referring still to FIG. 1 , and in accordance with an exemplary embodiment, blow molding system 100 may further comprise a fluid conduit 120 , a fluid control device 130 , and a controller 170 . Fluid conduit 120 may be operatively coupled to fluid inlet 140 and fluid outlet 150 . Further, fluid conduit 120 may be in fluid communication with blow stem 120 . Fluid control device 130 may be operatively coupled to fluid outlet 140 and controller 170 .
[0031] Referring to FIG. 4 , and in accordance with various exemplary embodiments, fluid conduit 120 may be any structure capable of conducting and exhausting air to and/or from blow stem 110 . In an embodiment, fluid conduit 120 comprises a supply channel 400 and an exhaust channel 410 . Supply channel 400 may be in fluid communication with fluid inlet 140 and blow stem 110 . In accordance with one exemplary embodiment, supply channel 400 may be configured such that it conducts an air supply from fluid inlet 140 to blow stem 110 . Fluid conduit 120 is configured such that air can be supplied to supply port 200 to maintain a pressure within mold 160 for a specified time. Thereafter, the air is exhausted through exhaust port 210 . As a result, the exhausted air creates a cooling airflow. The cooling airflow is conducted through exhaust port 210 to fluid outlet 150 . The cooling airflow may be managed and/or modulated by fluid control device 130 in conjunction with controller 170 .
[0032] In accordance with various exemplary embodiments, fluid control device 130 may be any structure capable of directing and/or modulating fluid flow. In an exemplary embodiment, fluid control device 130 comprises a pressure vessel coupled to one or more valves 420 . Fluid control device 130 may be coupled to controller 170 and fluid outlet 150 . Valve 420 may be a pressure regulator, for example, a flow control valve, a dump valve, and/or the like. Fluid control device 130 may be configured, such that a fluid exhausted through exhaust port 210 and exhaust channel 410 is managed and/or modulated by valve 420 . Valve 420 is configured to control the air flow from fluid outlet 150 and exhaust channel 410 , such that, a specified pressure is maintained in the parison and sufficient cooling air flow is provided to the parison.
[0033] Referring still to FIG. 4 , and in accordance with various embodiments, controller 170 may be any structure or system configured to regulate, direct, control, command, organize, manage, and or the like, any variable or monitor-able component of a blow molding system. In one exemplary embodiment, controller 170 may be operatively coupled to fluid inlet 140 , fluid outlet 150 , fluid control device 130 and valve 420 . Controller 170 may be configured to monitor and/or modulate, at least one of fluid inlet 140 , fluid outlet 150 , and fluid control device 130 . Controller 170 may be, for example, a timer, a digital controller, an analog controller, a computer and/or the like. Selection of an appropriate controller will depend on many factors including the number of parameters to be managed and/or monitored, the configuration of variable components, and the outputs provide by monitor-able components, among other factors. In an exemplary embodiment, controller 170 is a JZ10-11-UN20 programmable logic controller and/or a JZ10-11-UA24 programmable logic controller provided by Unitronics, Inc., with an address at 1 Batterymarch Park, Quincy, Mass., 02169.
[0034] In various embodiments, the blow molding system may comprise one or more sensors (not shown). The sensors may be any monitoring device suitable for measuring system parameters, such as, for example temperature, pressure, fluid flow rate, and/or the like. The sensor may be operatively coupled to controller 170 . Controller 170 may be configured to monitor and/or record data associated with the system parameters monitored by the sensor. As such, controller 170 is configured to control the system parameters by adjusting one or more variable components of blow mold system 100 , such as, for example, fluid inlet 140 , fluid outlet 150 , and/or fluid control device 130 .
[0035] In accordance with various embodiments, mold 160 may comprise a cooling system 430 . In one exemplary embodiment, cooling system 430 may be a channel within mold 160 , located between the interior cavity and the exterior surface of mold 160 . Alternatively, cooling system 430 may be a water bath. Cooling system 430 may be configured to supply cooling fluid to mold 160 . Mold 160 may further comprise parison 440 . Parison 440 may be in fluid communication with supply port 200 . When fluid is supplied through supply port 220 , parison 440 is stretched and/or forced to conform to the surface defining the internal cavity of mold 160 . Similarly, exhaust port 210 may be in fluid communication with the internal cavity of mold 160 and fluid control device 130 . As such, the blow molding system may be configured to create a cooling airflow in the internal cavity of mold 160 through exhaust port 210 where valve 420 is modulated by controller 170 .
[0036] Referring to FIG. 5 , and in accordance with an exemplary embodiment, blow molding system 100 may further comprise a pressure gauge 500 . Pressure gauge 500 may be operatively coupled to fluid control device 130 . Alternatively, pressure gauge 500 may be couple to fluid outlet 150 . In either embodiment, pressure gauge 500 may also be coupled to controller 170 . Controller 170 may be configured to monitor the pressure measured by pressure gauge 500 . Blow molding system 100 may also comprise an exhaust handler 510 . Exhaust handler 510 may be operatively coupled to fluid control 420 . Exhaust handler 510 may be configured such that air exhausted through fluid control 420 is conditioned by exhaust handler 510 . In accordance with various embodiments, exhaust handler 510 may be a muffler, a pressure vessel, and/or the like.
[0037] Referring to FIG. 6 , and in accordance with an embodiment, blow molding system 100 may further comprise a fluid bypass 600 . Fluid bypass 600 may be coupled to fluid inlet 140 and fluid outlet 150 . Fluid bypass 600 may further comprise fluid control 610 coupled to fluid outlet 150 . Fluid control 610 may be a valve or other fluid control device. Fluid control 610 may be in fluid communication with fluid inlet 140 and fluid outlet 150 and operatively coupled to controller 170 . Fluid control 610 may be configured to manage and/or modulate a supply of fluid to exhaust channel 410 through fluid outlet 150 at a specified condition. As such, fluid control 610 is configured to provide supply air through fluid outlet 150 initially. Thereafter, fluid control 610 may be modulated to allow for exhaust flow through fluid outlet 150 .
[0038] Referring to FIG. 7 , and in accordance with an embodiment, blow molding method 700 may comprise supplying parison 440 to mold 160 (step 710 ). Thereafter, pressurized air is supplied to blow stem 110 (step 720 ). The pressurized air, forces parison 440 to conform to mold 160 (step 730 ). Parison 440 is then allowed to stabilize in the mold (step 740 ). For example, the parison is allowed to stabilize in the mold sufficiently that air circulation within the parison would not cause the parison to deform significantly. Significant deformation would be any deformation outside of acceptable tolerances for the end product. After parison 440 is stabilized, an airflow is created within the internal cavity of mold 160 to cool and cure parison 440 (step 750 ). Parison 440 can then be removed from mold 160 (step 760 ). As such, the blow molding method 700 provides for efficient manufacturing of blow molded plastic products.
[0039] The present invention may be described herein in terms of functional block components, optional selections and/or various processing steps. It should be appreciated that such functional blocks may be realized by any number of hardware and/or software components suitably configured to perform the specified functions. For example, the present invention may employ various integrated circuit components, e.g., memory elements, processing elements, logic elements, look-up tables, and/or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. Similarly, the software elements of the present invention may be implemented with any programming or scripting language such as C, C++, Java, COBOL, assembler, PERL, Visual Basic, SQL Stored Procedures, extensible markup language (XML), with the various algorithms being implemented with any combination of data structures, objects, processes, routines or other programming elements. Further, it should be noted that the present invention may employ any number of conventional techniques for data transmission, messaging, data processing, network control, and/or the like.
[0040] For the sake of brevity, conventional data networking, application development and other functional aspects of the systems (and components of the individual operating components of the systems) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections might be present in a practical blow molding system.
[0041] The description of various embodiments herein makes reference to the accompanying drawing figures, which show the embodiments by way of illustration and not of limitation. While these embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that logical and mechanical changes may be made without departing from the spirit and scope of the invention. Thus, the disclosure herein is presented for purposes of illustration only and not of limitation. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not limited to the order presented. Moreover, any of the functions or steps may be outsourced to or performed by one or more third parties. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component may include a singular embodiment.
[0042] Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the invention. The scope of the invention is accordingly to be limited by nothing other than the claims that may be included in an application that claims the benefit of the present application, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, and C” may be used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Although certain embodiments may have been described as a method, it is contemplated that the method may be embodied as computer program instructions on a tangible computer-readable carrier and/or medium, such as a magnetic or optical memory or a magnetic or optical disk. All structural, chemical, and functional equivalents to the elements of the above-described embodiments that are known to those of ordinary skill in the art are contemplated within the scope of this disclosure. | In various embodiments, devices, systems, and methods for blow molding plastics are provided. In particular, the present disclosure provides for devices, systems, and methods that are configured to create an internal cooling airflow, using conductive and convective cooling thermal properties, such that the cycle time for blow molding plastics is reduced. The decrease in cycle time provided for in accordance with the disclosed devices, systems, and methods are between, approximately 15 percent and 35 percent. | 1 |
TECHNICAL FIELD
The present invention relates to devices for the carrying or serving of food and more particularly to sturdy disposable plates having integral handles, making the plate easier to carry and hold.
BACKGROUND OF THE INVENTION
Disposable plates are usually designed with enough durability to be reused, but they are intended to be used only once and then discarded. Disposable plates are usually inexpensive to manufacture, sold in bulk quantities, and not typically fragile. In contrast, reusable plates are expensive to manufacture, sold in small sets (usually 4 or 8), and can be quite fragile. Because of these features, disposable plates are often utilized at buffets or picnics and the like, and for meals where a large number of people make it undesirable to use nondisposable or reusable plates. Typically, the disposable plates are stacked, one on top of another, for use at such events, so that a person may select a plate and then serve himself.
Disposable plates have a long history of use and have been manufactured from a number of distinct materials. Reusable plates made of materials such as glass or ceramic have different structural concerns than most disposable plates. For example, reusable plates are generally heavier and sturdier than their disposable counterparts, but may be susceptible to chipping or breaking.
Disposable plates evolved from durable or reusable plates made from a variety of materials. Pewter tableware was popular and affordable in the eighteenth century, although other materials were considered more desirable. Decorated glazed porcelain plates were also popular, whereas earthenware was seen as a disfavored material. Solid silverware was out of the price range of most people, however, silver-plated tableware made an affordable alternative. In the nineteenth century, a blue and white pattern was popular on plate designs from stoneware to bone china. Pyrex or borosilicate glass tableware with heat-resistant properties was introduced in the early 1900's. The perception of materials desirable for plates has changed since the beginning of the last century. The materials used in manufacturing and the selling price of a plate tend to help catagorize the plate as disposable or reusable.
Service style is the way that food is presented to guests or the type of service offered to guests. Service styles are as numerous as cultures and nations on earth. The styles of service can range from elegant and lavish to very informal. Disposable tableware has generally been best suited to informal service situations.
Plates and food containers heretofore devised and utilized are known to consist basically of familiar expected and obvious structural configurations. The myriad of plate designs encompassed by the crowded prior art has been developed for the fulfillment of countless objectives and requirements. The structural concerns of durable and reusable plates are significantly different than those of disposable plates. Some of the most general requirements of disposable tableware are that they are economical, easy to hold and carry, and that the plates deter the spilling of food.
Disposable plates have significant material distinctions. Low-cost tableware of light construction are customarily economically manufactured on a large production basis. Lightweight paper plates are well-suited for dry foods. A pulp paper heavy-duty product creates a better quality of paper plate: it is good for serving hot foods; it is heat and cut resistant; and, it is economical and cost efficient for a large group. Laminated foam dinnerware provides a degree of cut-resistance and is a durable alternative. The lamination keeps food from soaking through the plate while the foam insulates against heat transfer. Non-laminated plates are less expensive yet practical for light menus. Plastic tableware is another alternative available in several designs and levels of quality. Heavy-duty plastic tableware is sold in a wide variety of colors and is both heat and cut resistant.
There are several problems associated with plates today. Issues with durable plates include a relatively high price, a need to clean them after use, and the difficulty in carrying or transporting reusable plates that were not designed for mobility. Even disposable plates have long had structural problems. These problems include a lack of significant rigidity, buckling or sagging from the weight of its contents, food sliding about the plate, food becoming co-mingled with other incompatible food, and the plate being difficult to hold or carry.
In the past, some disposable plates have had a tendency to be less rigid than similar dimensioned traditional reusable plates. The relative lack of structural rigidity is manifested by such plates bending, sagging, or folding between the portions of the plate being held, particularly when the plates are toting a heavy load. The items on the plate may settle into the middle of the plate, making the plate sag or buckle at its center. This exacerbates the problem as the sagging middle of the plate draws food from the perimeter down into the center. Eventually a large share of the weight of the items on the plate is gathered in the small area around its center. Food items being spread out and settled on the outer edges of a plate's food-contact area would enhance a loaded plate's rigidity, but food sometimes gravitates toward the center of the plate and this has a tendency to bow it down, further inducing food to slide to the middle of the plate.
There has always been a need for disposable plates that allow for the segregation of items placed on the plate. On low friction surfaces, such as the food-contact area of a smooth plastic plate, food may slide around the plate while the plate is being carried. Separation helps avoid blurring particular culinary distinctions. Examples include grease mixing with gravy and destroying their individual culinary flavors, or the sauce of baked beans being absorbed to soggy a hamburger bun. There is a need to hold the solid food items in the position that they were placed on the plate. To solve this, those skilled in the art have provided plate dividers to form isolated compartments on the face of the food-contact area of the plate. The dividers could aid in keeping different food elements separate, but could also induce a propensity for the disposable plate to fold along the line of the divider.
Carrying a disposable plate causes yet another inconvenience. Traditionally, a plate's food-contact area and rim form concentric circles of increasing size. The rim of the plate lacks a solid spot to grab and hold onto the entirety. A small circular rim encircling the food area of the plate leaves little room to grasp the plate while it is full. This drawback is especially relevant when one attempts to serve food onto the plate with one hand while holding the plate with the other hand. There is typically no handle or convenient method of holding a flimsy disposable plate, particularly when the plate is loaded with food. Additionally, placing a hand underneath the plate and carrying the plate like a tray or platter has the disadvantage of transferring the heat of potentially hot food to the fingers of those holding the plate in this fashion. Trays, platters, and even some plates, however, do have handles, but these handles tend to be manufactured of the same smooth substance that make up the balance of the plate and may therefore be difficult to hold.
The present invention is provided to solve these and other such problems with prior art devices.
SUMMARY OF THE INVENTION
The present invention provides a light, inexpensive, easily carried, easily held, disposable plate or bowl for the carrying and serving of food.
An aspect of the disclosed invention is a bowl or plate having a substantially circular food-contact area for receiving the food items and a raised oval, elliptical, rounded end, or obround plate rim. The substantially circular and oval combination create a stylish and functional blend of features where the rim is narrow along the minor axis of its oval perimeter and wider along the major axis. The wider portions of the rim naturally form handles that are conducive to having two hands holding opposite sides of the oval, elliptical, rounded end, or obround plate rim.
Another embodiment of the invention is a plate having a domed food-contact area. By having a substantially circular food-contact area that is slightly domed, the rigidity of the food holding portions of the plate is enhanced. Structural integrity is increased as the weight of the supported load is spread to the periphery of the substantially circular food-contact area. Individual compartments of a compartmentalized plate can also incorporate this feature on a smaller scale by having compartments whose substantially circular food-contact area is pitched toward the outside periphery.
Another embodiment of the disclosed invention has handles on the rim to grip the plate. These handles can include finger and/or thumb grooves for ease of holding and carrying the plate. The handles and especially their thumb grooves can be dimensionally optimized to balance ease of use with plate rigidity. The finger grooves can be located on the rim or on the underside of the food-contact area, so as to promote the ability to carry the plate and its contents with one hand.
In another embodiment of the invention, the plate has asymmetrical compartments formed by a dividing wall. Dividing walls are preferably “S” shaped to create two or more unequally sized compartments or sections. The dividing wall can be curved to discourage the plate from folding along a straight line of the dividing wall.
Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to better describe the features of the present invention, a number of drawing figures are appended hereto in which:
FIG. 1 is a perspective view of a plate, showing the substantially circular food-contact area with the oval rim of the plate;
FIG. 2 is a top view of the plate of FIG. 1 , showing the thumb handles and finger tactile areas;
FIG. 3 is a side view of the plate of FIG. 1 cut along the major axis, showing the domed food-contact area, sidewall, and the handle forming rim;
FIG. 4 is a side view of the plate of FIG. 1 cut along the minor axis, showing the domed food-contact area, sidewall, and the rim;
FIG. 5 is a cut away view of the sidewall of the plate of FIG. 1 ;
FIG. 6 is a cut away view of the plate thumb handle of the plate of FIG. 1 ;
FIG. 7 is a perspective view of a plate having a gusset in the thumb handles;
FIG. 8 is a cut away view of the plate thumb handle with a gusset of FIG. 7 ;
FIG. 9 is a perspective view of a plate, showing a compartmental divider;
FIG. 10 is a top view of the plate of FIG. 9 , showing the divided substantially circular food-contact area with the oval plate rim;
FIG. 11 is a side view of the plate of FIG. 9 cut along the major axis; and
FIG. 12 is a side view of the plate of FIG. 9 cut along the minor axis.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiment illustrated.
Referring generally to the appended FIGS. 1–12 , the embodiment of FIG. 1 is generally referenced by the number 10 in the following disclosure and drawings. Other components are similarly and consistently numbered throughout the specification and drawings. While the features of the present invention are preferred for use with thermoplastic containers, such as, for example, bowls, plates, food containers, and the like, manufactured by the SOLO CUP COMPANY of Highland Park, Ill., other such disposable materials for containers, bowls and plates may be capable of adaptation for implementation of these features as well. Some of the materials that can be used to manufacture disposable plates include, but are not limited to, plastics including thermoplastics and thermoset, fiber and molded fiber, foam, paper, cardboard, biodegradable materials, materials modified with lamination, fillers, or extenders and other plastic materials.
As shown in FIG. 1 , the disposable bowl or plate 10 has a substantially circular recessed surface or food-contact area 12 with a top side to receive food or other items to be put on the plate 10 . The underside of the substantially circular food-contact area 12 is shown as the surface where the plate 10 is set down, such as on a table or counter top. Both the top and underside of the substantially circular food-contact area 12 of the plate 10 are relatively smooth. The smooth top side of the substantially circular food-contact area 12 allows items placed on the plate 10 to slide around it, whereas the smooth bottom side can allow the plate 10 to slide or be pushed easily across a surface. The substantially circular food-contact area 12 forms an ideal location for the placement of a logo. A plate logo or brand indication may be helpful in creating brand name recognition for marketing the plate 10 .
Using one production method, a plate 10 having a sharp corner at the intersection of the circular food-contact area 12 and sidewall is formed. Using well-known thermoforming techniques, a radius, also known as a fillet, is imparted at this intersection to form a rounded corner. Some fluctuation has been found to occur such that the circular food-contact area 12 is not always perfectly round. The intent is, nonetheless, to produce a plate 10 having a circular food-contact area 12 and an elliptical rim 16 portion.
The disposable plate 10 is shown having a sidewall 14 whose lower end is integral with the substantially circular food-contact area 12 . The sidewall 14 loops around the entire perimeter of the substantially circular food-contact area 12 to keep food or other items from falling off the food-contact area 12 . The sidewall 14 is preferably positioned at an angle α slightly greater than perpendicular to the substantially circular food-contact area 12 for ease of placing food on the plate 10 and keeping the food from sliding off the plate 10 . The upper end of the sidewall 14 is also attached to the rim 16 of the plate 10 . The rim 16 of the plate 10 , shown in FIG. 2 , has a substantially circular center which is just slightly larger than the diameter of the substantially circular food-contact area 12 to make up for the sidewall 14 obtuse angle α that is greater than 90 degrees, preferably in the range of 90 degrees to about 180 degrees. The outer perimeter of the rim 16 is substantially oval. The dissimilar shapes of the rim's substantially circular interior and oval perimeter give the server ready-made thumb handles 18 for gripping and holding the plate 10 .
As shown in FIG. 2 , the widest portions of the rim 16 form thumb handles 18 and preferably include an indentation or depression on each end for the placement of the thumbs of the user. This indentation preferably narrows and wraps around the entire plate creating a curve in the curled-down rim 16 . The extra curve of the down-turned rim 16 adds rigidity to the plate 10 . Another benefit of this feature is to give the user a better grip on the thumb handles 18 of the plate 10 . The substantially circular food-contact area 12 has finger tactile areas 20 on the portion of the substantially circular food-contact area 12 nearest the thumb handles 18 . The finger tactile areas 20 are positioned so that the user can hold the plate 10 and carry its contents with one hand. The finger tactile areas 20 are located on the underside of the plate 10 for a user to feel where to optimally situate his or her fingers and to provide an enhanced plate gripping surface. For example, the user can place his or her thumb on top of either thumb handle 18 of the length of the oval rim 16 . The user's fingers naturally curl under the plate 10 and come to rest on the tactile area 20 on the bottom surface of the substantially circular food-contact area 12 . The fingers and thumb of the hand that is holding the plate 10 clench the plate 10 between the top of the thumb handles 18 of the rim 16 and the under side of the substantially circular food-contact area 12 . A preferred embodiment forms finger tactile areas 20 with concentric arcs on the substantially circular food-contact area 12 near the thumb handles 18 of the rim 16 . The finger tactile area 20 can also be a group of bumps, waves, a textured region, or the like, which achieves the purpose of grasping the disposable plate 10 in one hand.
Referring now to FIG. 3 , the embodiment of the disposable plate shown is a cross-section of the plate of FIG. 1 . The thumb handles 18 on the rim 16 of the plate 10 can be seen on each end of the cross-section of the plate 10 . The height of the sidewall 14 has been increased relative to the traditional standard of plate sidewalls. The increased length of the angled sidewall 14 provides the plate 10 with a deeper receptacle or food-contact area 12 to reduce the possibility of spilling the contents of the plate 10 because of the general portability and mobility requirements of disposable plate applications.
The sidewall 14 and rim 16 of the plate 10 have a contemplated purpose of maximizing structural strength and rigidity while fulfilling the ergonomic and ornamental intentions for disposable plates. The sidewall 14 height and angle α are preferably varied. The sidewall 14 can be highest near the thumb handles 18 and lowest at the midpoints of the sidewall 14 , between the two thumb handles 18 . The angle α between the food-contact area 12 and the sidewall 14 can also be dynamic. Preferably, the angle α is about 90 degrees or perpendicular at the midpoints of the sidewall 14 . The angle α can increase, toward, but less than 180 degrees, as the sidewall 14 approaches the thumb handles 18 . The angle α of the sidewall 14 neighboring the thumb handles 18 preferably decreases again to approximately 90 degrees along the line of the plate's major axis to provide for a strong and comfortable gripping location.
The rim 16 dimensions may also be varied. The rim's skirt, or vertical downturn flange 17 , can add rigidity to the plate 10 , wherein the rim 16 and the flange 17 cooperate to define an annular cavity 19 below an underside of the rim 16 (see FIGS. 3–5 ). The rim 16 preferably has the least downturn nearest the midpoints of the sidewalls 14 and the most downturn nearest the thumb handles 18 . The described rim 16 configuration has structural benefits as well as providing the plate 10 a side view alignment of the end of the rim's skirt 17 that appears parallel to both the perimeter of the food-contact area 12 and parallel to the surface on which the plate 10 is placed. An example of the sidewall 14 and rim 16 height and angle α fluctuations can be readily observed by comparing FIGS. 3 , 4 , and 5 . FIG. 5 is a cutaway view of the plate 10 between the major and minor axis in contrast to FIGS. 3 and 4 , particularly showing a greater angle α. The angle α between the food contact area 12 and the sidewall 14 preferably changes around the perimeter of the plate 10 with an angle α nearly perpendicular at the thumb handles 18 , the angle α becoming larger and then approaching 90 degrees again near the minor axis. In another preferred embodiment, there are further undulations forming waves in the rim 16 and providing additional rigidity to the plate 10 , such as a groove 16 a (see FIGS. 2 , 4 and 5 ).
FIG. 4 shows an embodiment of the disposable plate 10 having a domed food-contact area 12 . The perimeter of the substantially circular food-contact area 12 can rest firmly on a table or other surface while the center of the food-contact area 12 is slightly raised. Various heights of the domed food-contact area surface 12 can optimize the plate's use for specific applications. The doming of the food-contact area 12 creates a greater resistance to the perpendicular gravitational force from the weight of the food or other items placed on the plate 10 . The domed food-contact area 12 guides food to drift toward the perimeter of its circle, particularly liquid or fluid items placed on the plate 10 . The drifting distributes the weight of the items on the plate 10 around the periphery of the substantially circular food-contact area 12 , allowing for a greater load. A domed substantially circular food-contact area 12 serves to draw a fluid foodstuff away from the food it is commingling with. For example, grease, which can be a necessary but an unwanted byproduct of meal preparation, will drain to the edges of the substantially circular food-contact area 12 , preserving the rest of the food, centered in the plate, from saturation.
FIG. 6 is a view of the plate's thumb handle 18 . The gripping portion 40 of the thumb handle 18 is widest along the major axis and progressively narrows into the rim further from the major axis, creating a lens-like shape. The gripping portion 40 is bowed slightly to curve downward and provide a convenient, comfortable resting spot for the pads of the user's thumbs on the top of the thumb handles 18 . The arch narrows and forms the rim further away from the major axis. The width and extended skirt vertical flange 17 downturn are preferably largest at the center of the thumb handles 18 . The angle β formed between the thumb handles 18 and the sidewall 14 is slightly greater than perpendicular, between 90 and 180 degree, preferably about 100 degrees.
FIGS. 7 and 8 show a perspective view of a plate 50 having a gusset 52 in the thumb handles 18 and a cross-section view of the thumb handle 18 , respectively. The thumb handles 18 are to be wide enough to suit individuals with large thumbs; however, wide thumb handles 18 provide less plate structure rigidity. As the thumb handle grips move away from the sidewall 14 , the moment of force, the product of force multiplied by the perpendicular distance, requires less force to deflect a given distance. Another problem with thumb handles are the hinge points. The thumb handles 18 meet the sidewall 14 to form a sharp corner or a hinge point. The hinge point is a high stress area and makes the product weak. The sharp corner may be broken down with a generous radius, but the sharp corner may look better, therefore, the gusset 52 may serve as design feature to correct the rigidity with the following purposes. First, it shortens the perpendicular line of force and second, the gusset 52 acts as a truss or a brace that takes some of the load of weight from the plate. Additionally, the gusset 52 serves as a stiffening feature. The gusset 52 softens the angle at the flex point where the thumb handles 18 meet the sidewall. The more gradual slope of the angles provided as a result of the gussets 52 add strength and increase the amount of force necessary to deflect the thumb handles 18 . The path of the plate material changes direction as it travels from the sharp corner to the bottom of the gusset 52 . This interruption in the path gives the product strength in that area. The gusset 52 is preferably centered in a portion of the thumb handle 18 around the major axis.
As shown in FIG. 9 , one embodiment of the present invention is a plate 110 similar to that of FIG. 1 with the addition of a curved dividing wall 122 . The curved dividing wall 122 creates distinct food receptacle compartments 112 a of the food-contact area 112 on the plate 110 . The food receptacle compartments 112 a serve to allow a diner to segregate the items placed on the plate 110 into two subcategories. This aspect is particularly useful when food or items are incompatible. The asymmetrical food receptacle compartments 112 a formed by the curved dividing wall 122 serve the purpose of adding strength and rigidity to the plate 110 . The curve of the dividing wall 122 inhibits the plate 110 from bending along a straight line, rather the curved dividing wall 122 gives support to the food-contact area receptacle compartments 112 a by strengthening the capacity of the food receptacle compartments 112 a along the line of the curved dividing wall 122 . Also, configuring or positioning the curved dividing wall 122 along the general line of the major axis of the plate 110 increases the rigidity of the most likely location that such a plate 110 would collapse and fold under a heavy load, the center line along the plate's minor axis. A similarly positioned straight dividing wall would not provide this benefit.
FIG. 10 is a top view of the plate 110 of FIG. 9 . From atop the plate 110 , the size and shape of the food receptacle compartments 112 a show that one compartment is larger than the other. The food receptacle compartments 112 a form two nearly kidney shaped dissimilarly sized hemispheres with the dividing wall 122 curving generally near the line of the plate's major axis.
FIG. 11 is a cross section view of the compartmentalized plate 110 of FIGS. 9 and 10 cut along the major axis. This embodiment has a curved dividing wall 122 approximately half the height of the sidewall 114 . In a preferred embodiment, the angles of the dividing wall 122 , relative to the integrated portion of the food-contact area receptacle compartments 112 , and the sidewall 114 angles, are substantially similar. The curved dividing wall 122 is raised from the surface of the food-contact area and forms the food receptacle compartments. The dividing wall 122 can be relatively low in relation to the sidewall 114 or in another preferred embodiment, taller than the sidewall 114 . In yet another preferred embodiment, the food-contact area receptacle compartments 112 of a divided plate are maximized by having a relatively short dividing wall 122 , having angles nearly perpendicular to the food-contact area.
In FIG. 12 , the angles and height of the curved dividing wall 122 relative to the food receptacle compartments 112 can be substantially different than the height and the angle of the sidewall 114 of the plate 110 . The height and angle of the curved dividing wall 122 can be greater or less than the sidewall 114 depending on the segregation requirements of the items to be stored in the food receptacle compartments 112 . The angles and height of the curved dividing wall 122 also determine the size of the food receptacle compartments 112 , where a large angle (about 120 degrees to 170 degrees) of a relatively high curved dividing wall 122 can minimize the size of the bottom area of the food receptacle compartments 112 . The absolute height of the curved dividing wall 122 is preferably similar to the height of the sidewall 114 , with a steep, nearly vertical angle, optimizing the segregation capacity of the food receptacle compartments 112 while retaining the food items on the plate 110 .
Other embodiments of a multi-compartment plate 110 can be fabricated under the same design concept, the food receptacle compartments 112 being separated by a curvy shaped dividing wall 122 . The number of compartments can be determined by the amount of separate food items the plate is designed to hold. The curved dividing wall 122 is positioned to strengthen the holding capacity of the food receptacle compartments 112 . The addition of the curved dividing wall 122 supports the structure of the plate 110 along its center line or minor axis. Holding a plate that is loaded with heavy items by the two thumb handles 118 at the ends of the major axis naturally puts the most amounts of strain directly on the minor axis, encouraging the plate 110 to fold along the center line. The curved dividing wall 122 increases the plate's tolerance for a heavier load.
Each of the food receptacle compartments 112 divided and partitioned by the curved dividing wall 122 can be separately pitched. The slope of any and every food receptacle compartment 112 can be of a varied and unique angle or direction to drain fluids to the edges of the food receptacle compartment 112 . The downward slant can be directed to the outer edge of the plate 110 , or for other applications, toward the middle of the plate 110 . The pitch of each food receptacle compartments 112 can be steep or gradual, depending again on the desired application.
While the specific embodiment has been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying claims. | A disposable plate for carrying and serving food is disclosed. One particular aspect of the invention includes a plate with a substantially circular food-contact area with a substantially oval rim periphery. The rim is formed to make the plate easy to hold, with grooves adapted to accommodate fingers and/or thumbs. The present invention may be designed to segment the food storage areas of the plate into multiple compartments by using a divider wall. Also, the food-contact area can be slightly domed to force food to shift to the outer portion of the food-contact area and inhibit the food from slipping to the middle of the plate, thus keeping the plate center from sagging. | 1 |
This is a continuation of application Ser. No. 327,716, filed Dec. 4, 1981, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to a variable speed drive unit and more particularly to a variable speed driving having a box type clutch for conveyor drives or the like having input and output shafts, a clutch disc stack including a first series of drive plates located in a fluid reservoir and supported for rotation by a rotatable housing rotated by one of the shafts and a second series of driven discs interleaved with the drive plates and supported for rotation with the other of the shafts, and a piston actuator slideably located at one end of the clutch disc stack and adapted to compressively engage the clutch disc stack.
Conventional variable speed drive units have a small clutch, a stepping motor, and a control panel controlling the stepping motor, the motor and control panel comprising approximately 75 percent of the cost of the unit. The present invention has the object of providing a variable speed drive unit which needs no back-up such as a costly stepping motor and control unit. Another object is to provide such a unit which provides a variable speed drive unit having a self-controlling drive profile without the need for electronic back-up or extraneous controls. A further object is to provide this drive profile as a ramp or having a gradually increasing rate profile.
Universality in use as a drive unit in various types of applications and simplicity in operation make a drive unit much more valuable in the art than a unit having only one specific application. Thus, it is yet another object of the present invention to provide the above objects in a universal and relatively simple to operate construction.
It is another object of the present invention to maintain a positive pressure in the oil system and particularly the interior chambers which comprise a large part of the volume of the oil system to facilitate the movement of the oil whether it is hot or cold.
In some applications, it is desirable to run the oil pump constantly to filter the oil whether the machine is down or in operation. A further object of the present invention is to permit the oil pump to run constantly, but also include an optional bypass around the heat exchanger to permit the use of a smaller heat exchanger for a selected oil pressure.
A further object is to provide the variable speed drive unit of the present invention having a centrifugal pump driving the oil and which can be interchangeably positioned with the heat exchanger. The position of the pump and heat exchanger would depend upon the position of the drive unit desired in the application utilized.
Other objects and advantages of the instant invention will be apparent in the following specification, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a half cross sectional view of a variable speed drive unit embodying the principles of the present invention;
FIG. 2 is a side elevational view of the variable speed drive unit of FIG. 1;
FIG. 3 is an end elevational view of the variable speed drive unit of FIG. 2 in the direction 3--3; and
FIG. 4 is a schematic diagram illustrating the oil flow into and out of the variable speed drive unit of the present invention, including a pump and a heat exchanger.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 2 and 3 of the drawings and in accordance with a preferred embodiment of the subject invention, a variable speed drive unit is indicated generally at 10, having a drive shaft 12 capable of being mounted to a constant speed drive means (not shown) such as an electric motor or the like and having a driven shaft 14 mountable to an associated machine (not shown). The associated machine, by way of example, can include such devices as extruders, conveyors, pumps, fans, mixers, or any other driven machine that utilizes variable speed. As shall hereinafter become apparent, the variable speed drive unit 10 is adapted to selectively convert the constant rotary motion of the motor drive shaft 12 to a reduced variable speed range for the driven shaft 14 to suit the individual requirements thereof. Connector means between the shafts 12 and 14 and the components selected to be attached thereto are known in the art and will not be discussed herein.
A main housing 16 completely encloses the rotatable clutch assembly 17 (FIG. 1). The input 12 and output 14 shafts are rotatably supported within the main housing 16 by an interrelated bearing support system 18 supporting four bearings 20, 22, 24, and 26 around the shafts 12 and 14. Two bearings 20 and 22 are associated with the input shaft 12 and two bearings 24 and 26 support the output shaft, bearing 22 actually extending between the shafts 12 and 14 as will be described later.
Two rotatable housing structures 28 and 30 extend radially from the shafts 12 and 14, respectively, within the main housing 16. The input shaft housing 28 is comprised of two radially extending end walls 32 and 34 axially spaced from one another and interconnected at the radially outer extremes thereof by a two piece annular skirt section 36 comprising, in cross section, a first L-shaped member 38 bolted to end wall 32 at circumferentially spaced intervals by bolts 40 and a second member 42 spaced radially and axially from first member 38 and fixedly secured to both first member 38 by circumferentially spaced bolts 44 and end wall 34 by circumferentially spaced set screws 46. A porting annulus 48 is fixedly secured by circumferentially spaced bolts 50 to the main housing 16 around the output shaft 14. The annulus 48 has a radially extending flange 52 which mates with end wall 34 to form a labyrinth seal 54 and close off the interior of the main housing into two chambers, a working chamber 56 and a reservoir chamber 58. The porting annulus 48 also has means forming the portion of the bearing support system 18 supporting bearings 24 and 26 around the output shaft 14. The input shaft 12 is directly supported by the main housing 16 via bearing 20 held in place by sealed bearing assembly 60 including an annular seal 62 and two O-ring seals 64 and 66.
The output shaft housing 30 is comprised of an annular radially extending flange portion 68 and a C-shaped annular skirt portion 70 extending axially and radially outwardly from the flange portion 68. Output shaft housing 30 is disposed entirely within the working chamber 56. The radially inner, axially extending flange 72 of the housing 30 also comprises a portion of the bearing support system 18 for bearing 22 as referred to above. The input shaft 12 has an annular axially extending flange 74 at one axial extreme thereof upon which bearing 22 is disposed and held in place by snap ring 76 in groove 78. In this manner, the output shaft 14 through flange 72 is used to support the input shaft 12 in an interrelated fashion through bearing 22.
The outer periphery of the annular C-shaped section 70 of the output housing 30 and the inner periphery of the annular L-shaped member 38 of input housing 28 each have axially extending splines 80 and 82 respectively at circumferentially spaced intervals. The splines 80 of housing 30 are adapted to slideably receive a series of internally bored clutch drive plates 84. The plates 84 are each provided with a plurality of circumferentially spaced, radially inwardly extending notches adapted for splined engagement with the plurality of splines 80. Similarly, a series of friction discs 86 are interleaved with each of the drive plates 84 and carried by the splines 82 formed on the inner periphery of member 38 of input housing 28. Retainer means comprising annular retainer members 88 and 90 and bolts 92 disposed at circumferentially spaced locations thereof loosely retain the interleaved disposition of the plates 84 and the discs 86 and retain the plates 84 on the output housing 30 throughout the operation of the unit 10.
End wall 34, member 42, flange 52, and the radially outer surface 94 of the portion of the porting annulus 48 extending into the working chamber 56 form a subchamber 96 in which an annular piston 98 moves axially between the surface 100 formed by the end wall 34 and flange 52 and a radially inwardly extending abutment flange 102 extending from member 42. The piston 98 has an annular driving piston head 104 which when actuated by increased oil pressure in subchamber 96 is forced against the plates 84 and discs 86.
The oil pressure of subchamber 96 which controls the movement of the piston head 104 is determined by a multiplicity of orifice plugs 106 circumferentially and radially spaced at positions about the end wall 34. The number of plugs is determined in accordance with the given torque transmitting capacity of the unit 10. Each plug 106 comprises a threaded body portion 108 threadable into a bore 110 in the end wall 34. The body portion 108 of each plug 106 includes an orifice 112 through which oil can pass from subchamber 96 to the reservoir chamber 58. The plugs 106 can be arranged and rearranged between orificed and non-orificed plugs by removal of the cover plate 113 (FIGS. 2 and 3) for ready access to the plugs. It should be noted that the housing wall 16 is designed to be near enough to end wall 34 not to allow any plugs to fall into the machine when they are threadably disengaged.
In the present invention, a hydraulic fluid media is directed across the radial abutting surfaces of each of the drive plates 84 and friction discs 86 to maintain a positive oil film on each of the plates 84 and discs 86 which is subject to be viscously sheared whereby a controlled slippage, and a correspondingly reduced rotary motion to the output shaft 14 can be achieved by controlling the loading of the pressure between adjacent plates 84 and 86 as applied by the head portion 104 of the piston 98. The control of the movement of the piston 98 in the present invention is controlled completely within the system, as shall hereinafter be described, with no electronic input or control of any kind as previously utilized by prior art units.
As best illustrated in FIGS. 2 and 3, a centrifugal pump 114 is fixedly secured to the main housing 16 having an inlet port 116 below the oil level in the outer chamber 58 of the unit. The pump 114 is preferably of the centrifugal dual intake type as manufactured by Rutman Mfg. Co. and identified as a "Gusher" Pump, Model No. 11022-E, having two horsepower at 3460 r.p.m. (230/460 volts, three phase, with impeller #2292H). The pump output 118 is directed, as illustrated schematically by FIG. 4, into an ancillary heat exchanger 120 via conduit 122 through a pressure limit switch 124. A bypass conduit 126 is also included in order to use a smaller heat exchanger without having a prohibitive pressure drop. A pressure gauge 128 is included in the system to monitor the pressure drop through the heat exchanger 120 (22H, 1/2 h.p., 170 r.p.m.) to apprise the operator that sufficient operating pressure exists in the oil line or conduit 130 beyond the heat exchanger 120 as the line enters the drive unit 10. In the preferred embodiment, the pump 114 pumps 35 gpm at approximately 32 p.s.i. (at which the limit switch 124 is set) into the heat exchanger 120. The bypass flow around the heat exchanger 120 through the bypass conduit 126 is approximately 11 gpm as set by a 13/32 orifice 132. The oil is at an approximate pressure of 25 p.s.i. in the line 130 entering the drive unit 10, a pressure drop of only 7 p.s.i. across the heat exchanger 120.
A heater (1.5 kw, 480 volts) 134 is also mounted on the opposite side of the housing 16 from the pump 114 with its heating element 136 disposed in the oil reservoir 138 of the main chamber 58. The mount 140 for the heater 134 is identical to the mount 142 for the inlet port 116 of the pump 114 so that the pump 114 and heater 134 may be interchanged as space considerations externally around the unit permit or as otherwise desired. A cross wiring conduit 144 is disposed through the housing 16 to add to the ease of interchangeability of the pump 114 and heater 134 and provide the option of presenting the power wires to the unit 10 only from one side of the unit without exterior crossover.
In the subject invention, high limit 146 and low limit 148 temperature switches are included to control the heater 134. The housing 16, as illustrated in FIG. 2, also includes an oil level sight 150, a covered quick connect stem oil fill 152, an oil drain 154, and a cooling oil over temperature switch 156, as shown.
Oil from conduit 130 enters the drive unit 10 and breaks off in one direction to inlet port 158 of the porting annulus 48 (FIGS. 1 and 3). Referring now to FIGS. 1 and 3, the porting annulus 48 is utilized to convey hydraulic fluid from the inlet port 158 into the working chamber 56 and to the bearings 20, 22, 24, and 26 via the output shaft 14 and the input shaft 12. The inlet passageway 160 of the porting annulus 48 directs hydraulic fluid to two positions. The passageway 160 directly feeds orifice 162 into working chamber 56 to supply oil to the plates 84 and discs 86 and also to bearing 24. Passageway 160 also feeds into the output shaft lubricating system 164 via radial passageway 166 to lubricate bearings 26 and 22, and, via input shaft lubricating system 168, bearing 20.
Alternatively, the inlet port 158 may be bored axially through the input shaft 12 and communicate with the working chamber 56 radially outwardly of the discs via a passageway (not shown) that would be formed in end wall 32 and member 38.
Conduit 130 also breaks off in a second direction to supply oil to the piston subchamber 96. Conduit 130 branches into conduit 170 which feeds oil through a 15 micron filter 172 to conduit 174 which communicates with a four-way single acting spring return solenoid valve 176. The valve 176 is the primary control for the operation of the unit 10. The four positions of the valve 176 are conduits 174, 178, and 180, and a plug 182. Conduit 178 communicates with orifice 184 and inlet port 186 in the porting annulus 48 to feed oil to the piston subchamber 96 via passageway 188. Conduit 180 communicates as a drain to return oil to the reservoir chamber 58.
When the valve 176 is in the at rest position illustrated by FIG. 4, oil passes through the filter 172 and is returned directly to the reservoir 58. After the valve 176 is activated to the operating position (not shown), conduit 174 communicates with conduit 178, which in turn feeds oil under pressure to subchamber 96. This oil forces the piston 98 toward the plates 84 and discs 86 to engage the drive shaft 12 to driven shaft 14 and drive the machine associated with driven shaft 14. The oil in subchamber 96 is also bleeding through the orifices 112 back into the reservoir 58 at a selected rate such that the engagement of the shafts 12 and 14 occurs as a ramp or gradually increasing rate profile until a steady state is attained in subchamber 96 between the flow rates in and out.
Return of the valve 176 to the at rest position (as shown) stop the flow into subchamber 96 while oil continues to bleed through the orifice 112. The oil pressure in working chamber 56 forces the piston 98 out of engagement with the plates 84 and discs 86, again at a gradual rate or ramp rate, until the shafts are once again disengaged as the plates 84 and discs 86 become further spaced apart.
An additional feature of the present invention is the maintenance of a positive pressure (above atmospheric) in the oil system. This positive pressure is accomplished by injecting pressurized air (above atmospheric) into the oil system through the oil reservoir 58 via air inlets 190, 191, and 192 (inlet 191 is out of position in FIG. 1 for purposes of clarity; see FIGS. 2 and 5 for proper location). The pressurized air communicates with various parts of the oil system. Referring to FIG. 1, air from inlet 191 enters the oil reservoir 58 directly via passageway 194 and also positively pressurizes the oil system at bearing 26 via passageway 196. The pressure at bearing 26 at the portions of the oil system communicating with bearing 26 is further maintained by utilizing an O-ring seal 198 at the housing-bearing interface adjacent the bearing 26. Air from inlet 192 enters the oil system in an identical manner.
Pressurized air also enters the oil system from air inlet 190 via passageway 200 directly into the oil reservoir 58 and via passageway 202 to the bearing 20 to positively pressurize the oil system at bearing 20 and the portions of the oil system communicating with the bearing 20. Again an O-ring seal 204 is used to further maintain pressure in the oil system.
A pressurized oil system is particularly advantageous in the present invention where oil controls the piston, lubricates all the moving parts and also engages the plates and the discs by a shearing action. With a positive pressure in the oil system, the status of the unit (hot or cold) will not become as critical to the performance of the unit as in the past. Breathers 206 are also included which along with the seals 198 and 204 will release air from the oil system as the pressure rises above a desired level during the operation of the unit 10.
Thus there is disclosed in the above description and in the drawings an improved variable speed drive unit which fully and effectively accomplishes the objectives of the present invention. However, it will be apparent that variations and modifications of the disclosed embodiments may be made without departing from the principle of the invention or the scope of the appended claims. | A variable speed drive unit having a clutch disc stack including input and output shafts, a first series of drive plates located in a fluid reservoir and supported for rotation by a rotatable housing of the unit rotated by one of said shafts, a second series of driven discs interleaved with the drive plates and supported for rotation with the other of said shafts, a piston slideably movable in a piston chamber located at one end of the interleaved plates and discs and adapted to compressively engage the interleaved plates and discs, and a control for the piston providing a gradually increasing rated profile without the need for electronic back-up or extraneous controls. The control includes a two position input flow control and a fixed output flow control, comprising a series of plugs, which output control can be selectively varied between operations of the unit to provide alternate rate profiles for engagement and disengagement of the input and output shafts of the unit. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/509,381 filed Jul. 19, 2011, the entire disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The following description is provided to assist the understanding of the reader. None of the information provided or references cited is admitted to be prior art.
[0003] The strong interaction of a ferromagnetic material, such as iron, with an applied magnetic field derives from the ability of the atomic spins in the material structure to coherently align themselves with the applied field. Above a certain temperature, which is characteristic of the magnetic material and called the Curie temperature, thermal agitation prevents this coherent spin alignment, and the interaction with the applied field becomes much weaker. Above the Curie temperature, the material is paramagnetic, rather than ferromagnetic. Near the Curie temperature, the coherent alignment of atomic spins in an applied field results in a decrease in the magnetic entropy of the material. If the material is thermally isolated, so that its total entropy is conserved, this decrease in its magnetic entropy is compensated by an increase in its thermal entropy, and its temperature rises. This rise in temperature upon exposure to a magnetic field is known as the magnetocaloric effect. When the applied field is removed, the magnetic entropy rises and the thermal entropy decreases, lowering the temperature of the material.
SUMMARY
[0004] An illustrative method includes identifying at least partial degradation of a magnetocaloric material in a magnetic cooling system, wherein the magnetiocaloric material has a Curie temperature. The method also includes regenerating the magnetocaloric material by maintaining the magnetocaloric material at a regenerating temperature, wherein the regenerating temperature is different from the Curie temperature of the magnetocaloric material.
[0005] Another illustrative method includes forming at least one bed of a magnetic cooling system, wherein the at least one bed includes a magnetocaloric material, wherein the magnetocaloric material has a Curie temperature, and wherein a heat transfer fluid is configured to transfer heat to or from the magnetocaloric material in the at least one bed. The method also includes forming at least one valve of the magnetic cooling system to control a flow of the heat transfer fluid through the at least one bed and either a heater or a heat exchanger, wherein flow of the heat transfer fluid between the at least one bed and the heater regenerates the magnetocaloric material by maintaining the magnetocaloric material at a regenerating temperature, and wherein the regenerating temperature is different from the Curie temperature of the magnetocaloric material.
[0006] An illustrative apparatus includes a heat transfer fluid and a bed comprising a magnetocaloric material that has a Curie temperature. The bed is configured to allow the heat transfer fluid to transfer heat to or from the magnetocaloric material. The apparatus also includes a heater configured to maintain the magnetocaloric material at a regenerating temperature for an amount of time to regenerate the magnetocaloric material, wherein the regenerating temperature is different from the Curie temperature of the magnetocaloric material.
[0007] An illustrative system includes a first subsystem and a second subsystem. The first subsystem includes a first heat transfer fluid and a first bed having a first magnetocaloric material, wherein the first magnetocaloric material has a first Curie temperature. The first subsystem also includes a first valve configured to control whether the first subsystem operates in regeneration mode or cooling mode. The second subsystem includes a second heat transfer fluid and a second bed having a second magnetocaloric material, wherein the second magnetocaloric material has a second Curie temperature. The second subsystem also includes a second valve configured to control whether the second subsystem operates in regeneration mode or cooling mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.
[0009] FIG. 1 is a diagram illustrating the magnetocaloric effect in gadolinium (Gd) in accordance with an illustrative embodiment.
[0010] FIG. 2 is a diagram illustrating stages of an active magnetic regenerator cycle in accordance with an illustrative embodiment.
[0011] FIG. 3 illustrates a comparison between the isothermal entropy change in a 1.0 Tesla field (left panel) and heat capacity (right panel) of LaFeSiH and Gd in accordance with an illustrative embodiment.
[0012] FIG. 4 illustrates minimum and maximum fluid temperatures over the refrigeration cycle as functions of position in a magnetic refrigeration bed in accordance with an illustrative embodiment.
[0013] FIG. 5 is a diagram illustrating the performance of a magnetic refrigeration prototype with 5-layer LaFeSiH beds as compared to a magnetic refrigeration prototype with single-layer Gd beds in accordance with an illustrative embodiment.
[0014] FIG. 6 illustrates a differential scanning calorimetry (DSC) trace of a pristine sample of LaFeSiH in accordance with an illustrative embodiment.
[0015] FIG. 7 presents the DSC trace of the same material in FIG. 6 after being held close to its Curie temperature for over one year in accordance with an illustrative embodiment.
[0016] FIG. 8 is a diagram illustrating the recovery of age-split LaFeSiH by exposure to elevated temperatures in accordance with an illustrative embodiment.
[0017] FIG. 9 is a diagram illustrating the recovery of age-split LaFeSiH by exposure to lowered temperature in accordance with an illustrative embodiment.
[0018] FIG. 10 is a diagram of an active magnetic regenerator type refrigerator operating in cooling mode in accordance with an illustrative embodiment.
[0019] FIG. 11 is a diagram of an active magnetic regenerator type refrigerator operating in recovery mode in accordance with an illustrative embodiment.
[0020] FIG. 12 is a diagram of an active magnetic regenerator cooling system with two dual stage subsystems in accordance with a first illustrative embodiment.
[0021] FIG. 13 is a diagram of an active magnetic regenerator cooling system with two dual stage subsystems in accordance with a second illustrative embodiment.
DETAILED DESCRIPTION
[0022] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.
[0023] A magnetic refrigerator (MR) uses the magnetocaloric effect to pump heat out of a colder system and exhaust that heat to a warmer environment. The magnetocaloric effect refers to the rise in temperature of a material upon exposure to a magnetic field. When the applied field is removed, the magnetic entropy rises and the thermal entropy decreases, lowering the temperature of the material. This temperature change is shown in FIG. 1 for gadolinium (Gd), which is a magnetocaloric material with a Curie temperature of about 60° F. With this material initially at a temperature of 60° F., application of a 2-Tesla field, for example, will cause a temperature rise of 10° F. The temperature change increases as the strength of the applied field is increased.
[0024] Modern room-temperature MR systems may employ an Active Magnetic Regenerator (AMR) cycle to perform cooling. An early implementation of the AMR cycle can be found in U.S. Pat. No. 4,332,135, the entire disclosure of which is incorporated herein by reference. In one embodiment, the AMR cycle has four stages, as shown schematically in FIG. 2 . The MR system in FIG. 2 includes a porous bed of magnetocaloric material (MCM) and a heat transfer fluid, which exchanges heat with the MCM as it flows through the bed. In the figure, the left side of the bed is the cold side, while the hot side is on the right. In alternative embodiments, the hot and cold sides can be reversed. The timing and direction (hot-to-cold or cold-to-hot) of the fluid flow is coordinated with the application and removal of a magnetic field.
[0025] In the first stage of the cycle (“magnetization”), while the fluid in the bed is stagnant, a magnetic field is applied to the MCM, causing it to heat. In the second stage of the cycle (“cold-to-hot-flow”), the magnetic field over the bed is maintained, and fluid at a fixed temperature T Ci (the cold inlet temperature) is pumped through the bed from the cold side to the hot side. This fluid pulls heat from each section of the bed, cooling the bed and warming the fluid as it passes to the next section of the bed, where the process continues at a higher temperature. The fluid eventually reaches the temperature T Ho (the hot outlet temperature), where it exits the bed. Typically, this fluid is circulated through a hot side heat exchanger, where it exhausts its heat to the ambient environment. In the third stage (“demagnetization”), the fluid flow is terminated and the magnetic field is removed. This causes the bed to cool further. In the final stage of the cycle (“hot-to-cold-flow”), fluid at a fixed temperature T Hi (the hot inlet temperature) is pumped through the bed from the hot side to the cold side in the continued absence of the magnetic field. The fluid is cooled as it passes through each section of the bed, reaching a temperature T Co (the cold outlet temperature) which is the coldest temperature reached by the fluid in the cycle. Typically, this colder fluid is circulated through a cold side heat exchanger, where it picks up heat from the refrigerated system, allowing this system to maintain its cold temperature.
[0026] The time that it takes to complete execution of the four stages of the AMR cycle is called the cycle time, and its inverse is known as the cycle frequency. The “temperature span” of the MR system is defined as T Hi −T Ci , which is the difference in the inlet fluid temperatures. The AMR cycle is analogous to a simple vapor compression cycle, where gas compression (which causes the gas to heat) plays the role of magnetization, and where free expansion of the gas (which drops the gas temperature) plays the role of demagnetization. Although FIG. 2 illustrates the operation of a single-bed MR system, in alternative embodiments, multiple beds, each undergoing the same AMR cycle, may be combined in a single system to increase the cooling power, reduce the system size, or otherwise improve the implementation of the AMR cycle.
[0027] Typically, a magnetic field of 1-2 Tesla is utilized to effectively exploit the magnetocaloric effect for refrigeration. This field is usually provided by an assembly of powerful NdFeB magnets. The remanent magnetization of the highest grade of NdFeB magnets is about 1.5 Tesla. The use of a stronger field than this would improve MR performance, but to achieve fields in excess of the remanent magnetization, a large (and potentially prohibitive) increase in magnet size and weight is required. Thus, 1.5 Tesla is the field strength that provides a roughly optimum balance between MR system size and performance. As permanent magnet technology improves, magnets with remanent magnetizations greater than 1.5 Tesla may be obtained. In this case, the optimum field strength of an MR system will increase accordingly.
[0028] The permanent magnet assembly is generally the most expensive component in the MR. To make the best use of this expensive resource, the magnetocaloric material used in the MR should possess the strongest possible magnetocaloric effect. This material should also avoid the use of any toxic, reactive, or rare (and therefore expensive) constituents. The former consideration rules out the commercial use of Gd, for example, which is nontoxic, inert, and inexpensive but has a weak magnetocaloric effect. MR systems employing Gd, or other materials of comparable magnetocaloric strength, would be too large for commercial utility. Lanthanum iron silicon hydride (LaFeSiH) is one of the most promising magnetocaloric materials for use in commercial MR systems. A description of LaFeSiH can be found in an article by Fujita et al. titled “Itinerant-electron metamagnetic transition and large magnetocaloric effects in La(Fe x Si 1-x ) 13 compounds and their hydrides,” Physical Review B 67 (2003), the entire disclosure of which is incorporated by reference herein. This material has a strong magnetocaloric effect. FIG. 3 , for example, shows the two most important measures of magnetocaloric strength, the isothermal entropy change (left panel) in a 1.0 Tesla field and heat capacity (right panel) of LaFeSiH. For comparison, the same properties for Gd are also shown. Because of its greatly enhanced magnetocaloric strength, MR systems employing LaFeSiH can be much more compact than a system employing Gd. Although LaFeSiH has the rare earth metal La (Lanthanum) as a constituent, it remains inexpensive as La is one of the most abundant of these elements.
[0029] In most cooling applications, the temperature span will be substantial, typically about 30° C. (54° F.) or larger. Although the overall span supported by an MR system may be large, the temperature within a given axial section of a bed in the system will remain within a relatively narrow range over the refrigeration cycle. FIG. 4 , for example, shows the theoretical minimum and maximum fluid temperatures over the refrigeration cycle as a function of axial position in the bed for a particular MR system designed as a residential air conditioner. For this case, although the overall temperature span is 37° C., each axial position in the bed experiences a temperature variation of only ±2° C. around its mean value. If the bed is composed of a single magnetocaloric material, some regions of it will therefore be at temperatures away from its Curie temperature. These regions of the bed will undergo little entropy change and will have low heat capacity (see FIG. 3 ). These regions will behave more like passive regenerators and will contribute little to the cooling power of the system. This inefficient use of bed volume can be circumvented through the use of layered beds, which greatly enhance the performance of a MR system. In a layered bed, each layer contains a magnetocaloric material with Curie temperature matched to the average temperature of that layer over the cycle. By choosing the Curie temperatures of the layer materials in this manner, every layer will have a strong entropy change during the cycle and a large heat capacity. All layers will therefore contribute actively during the refrigeration cycle, greatly improving the overall performance of the system. In addition to having a strong magnetocaloric effect, the Curie temperature of LaFeSiH can be easily controlled between ±60° C. (the range of interest for room temperature MR systems) by varying the hydrogen (H) content, making it ideal for use in a layered bed.
[0030] The advantages associated with the use of layered beds of LaFeSiH are demonstrated in FIG. 5 , which shows the measured cooling power of a prototype MR system as a function of temperature span with beds formed from 5 layers of LaFeSiH. In alternative embodiments, fewer or more layers may be used. For comparison, the figure also shows the performance of identical beds with a single layer of Gd under the same operating conditions. At a temperature span of 13° C., for example, the layered LaFeSiH beds provide over three times the cooling power of the Gd beds.
[0031] Although LaFeSiH appears to be an ideal material for use in a MR, its properties are not stable. This material has been shown to undergo a gradual deterioration of its magnetocaloric strength when it is stored at a temperature very close to its Curie point, as described in an article by A. Barcza et al. entitled “Stability and magnetocaloric properties of sintered La(Fe,Mn,Si) 13 H z alloys”, presented at the IEEE International Magnetics Conference (Taipei, Taiwan) 2011, session ED-07 (hereinafter “A. Barcza et al.”), the entire disclosure of which is incorporated by reference herein. This deterioration is most readily observed in Differential Scanning calorimetry (DSC). FIG. 6 illustrates the DSC trace of a pristine sample of LaFeSiH, which has a single, sharp peak. The figure also illustrates the width of the peak in the DSC trace. For comparison, FIG. 7 shows the DSC trace of the same sample after it has been kept close to its Curie temperature for over one year. When kept at a temperature close to its Curie temperature, the DSC trace shows that the ferromagnetic to paramagnetic phase change broadens in width and declines in height. Eventually, the initially large and sharp transition of this material will split into two broad, shallow peaks (“age-splitting”), as illustrated in FIG. 7 and in A. Barcza et al. The age-splitting of the DSC trace is accompanied by a reduction in the entropy change of the material, as measured by magnetometry and as also illustrated in A. Barcza et al. The rate at which the splitting occurs depends on temperature. For LaFeSiH with a 2° C. curie point stored at 2° C., significant broadening of the peak takes about 10 days, and a split peak takes about 60 days to form. For LaFeSiH material with a 20° C. curie point stored at 20° C., a split peak develops in about 10 days. For material with a 32° C. curie point stored at 32° C., a split peak develops in about 5 days.
[0032] The ageing process for LaFeSiH appears to not depend on the synthesis method, as long as the hydrogen content is less than 1.5 per formula unit. The age-splitting process was seen in material that was arc melted, then annealed for several weeks to form the 1-13 phase, then hydrided. The age-splitting process was also seen in material that was rapidly solidified by melt spinning or atomization, and then annealed for a few hours or less to form the 1-13 phase, and then hydrided. The ageing process was seen in different samples of LaFeSiH with slightly different compositions, such as La 1.29 (Fe 0.88 Si 0.12 ) 13 H y and La 1.2 (Fe 0.888 Si 0.112 ) 13 H y . The ageing process was also seen in a sample of Pr 0.6 La 0.6 (Fe 0.888 Si 0.112 ) 13 H y , where Pr was substituted for some of the La to increase the magnetocaloric strength. Thus, the age-splitting process will generally occur in magnetocaloric materials of the form RE(TM x Si 1-x ) 13 H y material (where RE represents a rare earth element such as La, Ce, Pr, or Nd, and TM represents a transition metal such as Fe, Cr, Mn, or Ni, x<0.15, and y<1.5). In an illustrative embodiment, the value of y can be between approximately 0.8 and 1.5. Alternatively, a different range of y values may be used. As discussed herein, different values of y can be used to generate magnetocaloric materials having different Curie temperatures.
[0033] When used in an MR system, the magnetocaloric material will inevitably be exposed to temperatures close to its Curie temperature. Indeed, in a layered bed, the material in a layer is selected to have a Curie temperature equal to the average temperature seen by that layer during the MR cycle. Thus, if partially hydrogenated LaFeSiH, or more generally RE(TM x Si 1-x ) 13 H y , is used in an MR system, its magnetocaloric properties will degrade over time. In spite of its significant advantages over other magnetocaloric materials, this degradation in the magnetocaloric properties of partially hydrogenated RE(TM x Si 1-x ) 13 H y material could potentially preclude its use in a commercial MR system.
[0034] Applicants have discovered that when degraded RE(TMxSi 1-x ) 13 H y material is subsequently held at a temperature away from (e.g., either a higher or a lower temperature) its Curie point, the degradation process reverses and eventually the properties of the material return to their initial condition. Moreover, Applicants have found that the recovery of the material proceeds more quickly at higher temperatures, as shown in FIG. 8 . Material (i.e., LaFeSiH) with a Curie temperature of 26.7° C. was allowed to age-split by storage at this temperature for over one year, until the width of the magnetic transition as measured by DSC reached 14° C. The original magnetic transmission as measured by DSC was 2.1° C. The degraded material was then exposed to different temperatures as shown in the figure (i.e., 38.5° C., 44° C., 60° C., and 100° C.). Exposure at 44° C. for about 6 days was sufficient to completely restore the material to its initial condition, and exposure at 60° C. for about 3 days was sufficient to completely restore the material to its initial condition. Exposure at 100° C. for less than 1 day was sufficient to obtain complete reversal of age-splitting. Applicants have also found that age-splitting degradation of Pr 0.5 La 0.5 (Fe 1-x Si x ) 13 H y is also completely reversible by this heat treatment. Recovery of the original sharp magnetic transition of age-split LaFeSiH is also obtained by exposure to lowered temperature, although the process proceeds more slowly, as shown in FIG. 9 . The LaFeSiH material initially had a 1.2° C. wide magnetic transition, that had been widened to 4.4° C. after a 6 day hold near its 37° C. Curie point. Recovery was obtained by holding the material at 5° C. Recovery was complete after 100 days. In an illustrative embodiment, the regenerating temperature used to recover the magnetocaloric material can be less than a maximum temperature at which hydrogen may begin to leave the magnetocaloric material. The maximum temperature is approximately 180° C.
[0035] Because the age-splitting degradation can be completely reversed in a relatively simple manner, RE(TM x Si 1-x ) 13 H y materials can be used in suitably modified MR systems, which forms the basis of the subject matter described herein. In the usual mode of operation of an MR system with layered beds of magnetocaloric material, the material layers will remain close to their respective Curie temperatures, which will cause deterioration of the magnetocaloric material. In addition, when the system is not operating, the portion of the magnetocaloric material with Curie point near ambient temperature may also deteriorate. As such, Applicants have developed a modified MR system that is configured to hold the layers of magnetocaloric material at a temperature that differs from the Curie temperature of the magnetocaloric material to reverse whatever age-splitting degradation may have occurred and to recover their full magnetocaloric effect. The temperature at which the magnetocaloric material is held, which can be higher or lower than the Curie temperature of the magnetocaloric material, can differ from the Curie temperature by 10° C., 25° C., 50° C., 100° C., etc. depending on the desired rate of recovery, the system capacity, etc. In an illustrative embodiment, temperature at which the magnetocaloric material is held can differ from the Curie temperature by approximately 10° C.
[0036] In one illustrative embodiment, an MR system employs RE(TM x Si 1-x ) 13 H y as the magnetocaloric material and has a heating element plumbed into the flow system. When the MR system would otherwise be idle (e.g., a residential air conditioner at night), the heating element can be activated. The MR system would then circulate heated fluid through the magnetocaloric material, completely reversing any age-splitting that may have occurred since the last high-temperature treatment.
[0037] In the particular case of a MR system that normally absorbs heat at a cold heat exchanger (CHEX) and exhausts heat at a hot heat exchanger (HHEX), a heater can be plumbed in parallel with the cold heat exchanger. In normal cooling mode, flow is directed through the CHEX and the HHEX, as shown in FIG. 10 . As illustrated in FIG. 10 , an AMR type refrigerator is operating in cooling mode, including one or more demagnetized beds providing cooling to a cold heat exchanger in thermal contact with the load to be cooled. One or more magnetized beds are rejecting heat to a hot heat exchanger. In one embodiment, each bed comprises layers of RE(TMxSi1-x)13Hy with Curie points approximately ranging from Tc to Th, where Th>Tc.
[0038] FIG. 11 illustrates an AMR type refrigerator operating in recovery mode. In one embodiment, a heater in series with the beds heats the beds to more than 10 C above the highest Curie point of the material in the beds, and the heat exchangers are bypassed. When the recovery mode is started, a valve switches flow away from the cold heat exchanger and redirects the flow to the heater, as shown in FIG. 11 and discussed in more detail below. A second valve may be added to switch flow away from the hot heat exchanger when in recovery mode (also see FIG. 11 ). These two valves thermally isolate the MR system so it may be heated to a temperature approximately 10° C. higher than the Curie point of all magnetocaloric materials in the system using a relatively small amount of heater power. If either the magnet motion or fluid flow reversal is suspended during the recovery mode, operation of the AMR cycle is suspended, which reduces the amount of heater power required to stay in recovery mode. Because magnet motion and fluid flow reversal utilize additional electrical power, suspending these operations also reduces the amount of power consumed by the system while in recovery mode.
[0039] In an alternative embodiment, in addition to having a heating element, a cooling system can include two independent MR subsystems. The first MR subsystem can provide cooling as in FIG. 10 , while simultaneously the beds of the second subsystem undergo heat treatment as in FIG. 11 , to reverse age-splitting. After a certain duration under these operating conditions (e.g., 1 hour, 2 hours, 4 hours, 12 hours, etc.), the MR subsystems can be switched, with the second subsystem providing cooling, and the first subsystem undergoing heat treatment. Under periods of peak cooling demand, both MR subsystems could provide cooling power. In another alternative embodiment, the system can incorporate more than two subsystems, with some subsystems providing cooling power while the remaining subsystems undergo heat treatment.
[0040] In another alternative embodiment, the cooling system can have two stages, with each stage containing layered AMR beds. The cold stage can have Curie temperatures ranging from T c to T m , while the hot stage can have Curie temperatures ranging from T m to T h , where T h >T m >T c . In an air conditioner implementation, T c may have a value of 10° C., T m may have a value of 25° C., and T h may have a value of 40° C. In alternative embodiments and/or implementations, different temperature values may be used. When recovery of the hot stage magnetocaloric material is desired, the cold stage can operate in cooling mode, generating a cold outlet fluid stream with temperature near T c . This cold fluid, instead of flowing through the cold side heat exchanger, can be directed through the hot stage to bring the hot stage temperature near T c . Because T c is well below all Curie temperatures in the hot stage, exposure to this temperature would reverse any age-splitting in the hot stage. Similarly, when recovery of the cold stage magnetocaloric material is desired, the hot stage can operate in cooling mode and can therefore generate a hot outlet fluid stream with a temperature near T h . This hot fluid, instead of flowing through the hot side heat exchanger, can be directed through the cold stage, bringing its temperature to approximately T h . Because this temperature is well above all Curie temperatures in the cold stage, exposure to this temperature would reverse any age-splitting of the cold stage material.
[0041] In another alternative embodiment, the system can include two independent MR subsystems, with each subsystem having two stages, a hot stage and a cold stage as in the above-described embodiment. When maximum cooling power is desired, both subsystems can be run in parallel, with each providing cooling, as shown in FIG. 12 . In FIG. 12 , the stages connected to the pump and hot HEX have LaFeSiH as the magnetocaloric material with Curie points ranging from Th to Tm. The stages connected to the cold HEX have LaFeSiH MCM with Curie points ranging from Tm to Tc. In an illustrative embodiment, the MCM with Curie point at Tm is at the end of the bed that is connected to another bed. When less cooling power is needed, one subsystem could be run in cooling mode, while the other subsystem could be run in recovery mode to restore the performance of its magnetocaloric material as shown in FIG. 13 . In this figure, the lower subsystem is providing cooling power, while the upper subsystem is in recovery mode. At least a portion of the cold outlet fluid stream emerging from the demagnetized beds of the lower subsystem is diverted into the hot stage beds of the upper subsystem. Simultaneously, part of the hot outlet fluid stream of the magnetized beds of the lower subsystem is diverted to the cold stage beds of the upper subsystem. This embodiment can also be modified to incorporate more than two subsystems, with some subsystems providing cooling power while the remaining subsystems undergo heat treatment. Each subsystem in this generalized case could have two stages as described above.
[0042] In another alternative embodiment, the possibly multiple beds of a magnetic refrigeration system can be designed to be easily removable and replaceable from the system. Beds that have been degraded from age-splitting can then be removed and replaced with pristine beds. In a separate device that can be physically remote from the magnetic refrigeration system, the degraded beds can be returned to pristine condition through exposure to temperatures sufficiently far from the Curie temperatures of all the layers they contain. This device, for example, could be a simple flow loop with a heater, capable of circulating fluid at an elevated temperature through the degraded beds, or an oven for holding the beds at an elevated temperature. Once restored to pristine condition, these beds can then be re-installed in the magnetic refrigeration system.
[0043] Any of the operations described herein can be performed by a computing system that includes a processor, a memory, a transmitter, a receiver, a display, a user interface, and/or any other computer components known to those of skill in the art. Any type of computing system known to those of skill in the art may be used. In one embodiment, any of the operations described herein can be coded into instructions that are stored on a computer-readable medium. A computing system can be utilized to execute the instructions such that the operations are performed.
EXAMPLES
[0044] To verify the effect on magnetic refrigerator performance of the age-splitting degradation, and to verify that elevated temperature treatment was effective at reversing this degradation, the beds of a magnetic refrigerator were packed with five layers of La(Fe 0.885 Si 0.115 )H y material, with each layer having a different value of y and therefore a different Curie point. The Curie points of the layers were initially 8° C., 11° C., 15° C., 18° C. and 21° C. The machine was tested under a standard set of operating conditions, where the cycle frequency was 3.33 Hz, the flow rate was 6 lit/min, the hot inlet temperature was 25° C., and the cooling load, provided by an electrical heater, was 400 watts. Before operation as a MR, the LaFeSiH in the beds was suffused with 35° C. aqueous fluid for 80 hours to bring the material to its initial state. The temperature span of the machine with pristine material under the standard operating conditions was found to be 13.4° C. The machine was then left in a non-operating state at an ambient temperature of 22° C. for ten days. In this state, the materials with Curie temperatures of 18° C. and 21° C. would be expected to undergo age-splitting degradation, and indeed, the temperature span of the machine after this 10-day treatment under the standard operating conditions dropped to only 2.9° C. The LaFeSiH MCM was then suffused with 50° C. aqueous fluid for 19 hours to bring the material to its initial state, and then the temperature span of the machine in AMR mode at the standard condition of a cooling load of 400 watts and a hot inlet temperature of 25° C. was measured to be 13.2° C. Thus bringing the LeFeSiH MCM to a temperature more than 10° C. above the Curie point of the material for 19 hours was able to restore the performance of the MCM after a substantial reduction in performance that occurred when the MCM was kept close to its Curie point for ten days.
[0045] The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable”, to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.
[0046] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
[0047] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0048] The foregoing description of illustrative embodiments has been presented for purposes of illustration and of description. It is not intended to be exhaustive or limiting with respect to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosed embodiments. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. | A method includes identifying at least partial degradation of a magnetocaloric material in a magnetic cooling system, wherein the magnetiocaloric material has a Curie temperature. The method also includes regenerating the magnetocaloric material by maintaining the magnetocaloric material at a regenerating temperature, wherein the regenerating temperature is different from the Curie temperature of the magnetocaloric material. | 5 |
BACKGROUND OF THE INVENTION
[0001] This invention provides a blowout-preventer-stack one-trip test tool and method for the oil-and-gas drilling industry.
[0002] Drilling for petroleum, especially under water and in deep water, is a very expensive operation, with costs accruing every day whether actual drilling is occurring or not. The cost of suspending drilling operations for required safety testing is immense.
[0003] The blowout preventer (BOP) or more precisely the blowout preventer stack of several different types of BOPs is a standard and required piece of safety equipment for oil- and -gas drilling. It is located at the wellhead, which, for deep-water drilling, is at the bottom of the sea. It protects against blowouts caused by kicks or bumps of sub-surface pressure rising from the well.
[0004] The drill string is composed primarily of sections of drill pipe surrounded by a casing. The drill pipe moves into and out of the well as drilling progresses. The casing stays in place after it is initially set. Both the drill pipe and the casing are subject to separately varying levels of sub-surface pressure. Drilling fluid or drilling mud is injected into the drill pipe and separately into the casing at closely monitored pressures to counteract the sub-surface pressure. Blowout preventers serve the purpose of sealing off either the casing or the casing and the drill string of the entire well to prevent sub-surface pressure from overwhelming the counteracting pressure of the drilling mud.
[0005] Of the various types of blowout preventers in a stack, annulars and fixed and variable rams are designed to seal the casing around the drill pipe while leaving an area to accommodate and not damage the drill pipe. The casing is more susceptible to loss of control of pressure kicks than the drill pipe is, and damage to the drill pipe can cause delays or even complete loss of a well. Blind and shear rams, however, are designed to completely seal off the entire casing, and will damage or shear any drill pipe inside the casing.
[0006] Blowout preventer stacks are a regulated and required element of drilling. The regulations require that blowout preventer stacks must be tested frequently and thoroughly. Testing requires that drilling operations be suspended, that the drill string be pulled out of the hole, that a test plug be set at the wellhead, that testing of the rams and annulars be performed, that the test plug be removed, and that the drill string be run back into the hole in order to resume drilling.
[0007] Drill pipe is made in typically 30-foot sections, and a drill string has to be assembled at the drilling rig from those sections of drill pipe as the drilling progresses. When the drill string is pulled out of the hole, the sections of the drill pipe have to be disassembled and stacked, and then reassembled on the next trip into the hole. Deep-water drilling requires vast lengths of drill pipe just to reach the wellhead, and then more vast lengths of drill pipe to drill into the seabed. Pulling the drill string out of the hole, running the test plug into and out of the hole, and putting the drill string back into the hole, in deep water, is an operation that can take several days and several cycles of disassembly and reassembly of thousands of sections of drill pipe.
[0008] Thorough testing of a blowout preventer stack presently requires more than one trip into the hole, which further delays resumption of drilling operations, because testing of rams fixed for different diameters of pipe require the insertion and removal of those different diameters of pipe, and testing of the blind and shear rams must be performed with no pipe present in the blowout preventer at the wellhead.
[0009] For some phases of BOP testing, the wellhead immediately below the BOP stack must be tightly sealed off from the well below, by the test plug, in order to prevent leakage of any pressure coming form or going into the sub-surface well and making it impossible to determine if the blowout preventers are properly holding pressure between each BOP and the test plug at the wellhead. Presently this sealing and unsealing of the test plug at the wellhead requires more than one trip into the hole and carries a risk of not being able to unseal the wellhead and resume drilling operations.
[0010] The frequent and thorough testing of blowout preventer stacks is an important safety precaution that is required to be done, but at present, especially for deep-water drilling, the testing of blowout preventer stacks requires long, costly suspensions of drilling operations.
SUMMARY OF THE INVENTION
[0011] The present invention provides a blowout-preventer-stack one-trip test tool and method providing a solid test pin for sealing the test plug in the wellhead, a running tool for securely placing, separating from, reattaching, and removing the solid test pin, testing all fixed and variable rams and annulars and testing all blind and shear rams without damage to pipe, in one trip, and a fail-safe secondary provision for removing the solid test plug on a second trip with an emergency retrieval tool if necessary.
[0012] The present invention allows thorough testing of blowout preventer stacks in significantly less downtime of suspended drilling, by providing performance of all tests of all blowout preventer components in one trip into and out of the hole, by securely sealing the standard test plug at the wellhead to prevent leakage, and by providing an improved primary method of disconnection and re-connection at the wellhead for retrieval, and also a backup secondary method for retrieval using an emergency retrieval tool.
BRIEF DESCRIPTION OF DRAWINGS
[0013] Reference will now be made to the drawings, wherein like parts are designated by like numerals, and wherein:
[0014] FIG. 1 is a partially cutaway perspective view of the invention assembled.
[0015] FIG. 2 is a partially cutaway exploded view of the invention.
[0016] FIG. 3 is a schematic view of the invention in four stages of its use at the wellhead and blowout preventer stack.
[0017] FIG. 4 is a schematic view of primary uncoupling and retrieval of the solid test pin, and the secondary, backup provision.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Referring to FIG. 1 and FIG. 2 , our blowout-preventer-stack one-trip test tool 1 provides a solid test pin 2 having a bottom portion threaded with standard drill-pipe threads 23 that include a first plug 23 a, a second plug 23 b, and a socket 23 c for the purpose of connecting to a standard test plug. Standard drill-pipe threading is intended to be used at relatively high torque, with no additional seal, to form a sufficient pressure-holding connection. The solid test pin further has a large entry bevel 3 , a primary connector surface 4 having threads 24 that include a plug 24 a and a socket 24 b different from standard drill-pipe threads, and a secondary connector surface 11 having standard drill-pipe threads 23 with first plug 23 a.
[0019] The threading 24 with plug 24 a on the primary connector surface 4 is adapted to form a sufficient pressure-holding connection at a relatively low right-hand torque, and may be used in conjunction with a pin seal 28 mounted in a pin-seal groove 27 on the primary connector surface to increase the effectiveness of the relatively low-torque connection. The primary connector surface 4 , and the large entry bevel 3 are adapted to be easily disconnected from and reconnected with the running tool 5 while the assembly is at the wellhead, at the remote end of a long length of drill string.
[0020] The secondary connector surface 11 having standard drill-pipe threads 23 with first plug 23 a is adapted to provide a backup means of retrieval in case re-connection of the running tool 5 to the primary surface connector 4 is not successfully performed. This backup means of retrieval can be performed using an emergency retrieval tool 12 instead of the running tool.
[0021] The running tool 5 has a bottom portion adapted to easily disconnect and re-connect with the test pin 2 , while the assembly is at the wellhead, having a large entry bevel matching that of the solid test pin, which promotes correct placement, and having threading 24 with plug 24 a and socket 24 b matching that of the primary connector surface 4 of the solid test pin, adapted to form a sufficient pressure-holding connection at a relatively low torque.
[0022] A centralizer 6 is mounted surrounding a portion of the running tool 5 , and serves to keep the tool in the center of the BOP stack during the time that it is disconnected, so that it can be more easily re-connected to the solid test pin.
[0023] A drill-pipe connector 7 at the top of the running tool 5 has standard drill-pipe threading 23 with socket 23 c so that the test assembly can be run into the hold using standard drill pipe, with or without a special-purpose test joint.
[0024] Referring to FIG. 3 and FIG. 4 , in use, our blowout-preventer-stack one-trip test tool 1 is made up on a standard test plug and is lowered at the end of a drill string, through the casing 21 and the blowout preventer stack until the test plug is set in the wellhead at the mudline 20 or sea floor. The standard test plug 25 has an opening 26 that is securely plugged by the solid test pin 2 , so that no leakage occurs between the BOP stack and the well below the test plug.
[0025] If the specific blowout preventer stack contains more than one fixed ram 35 , 36 , designed to accommodate different diameter sizes of drill pipe, then a special-purpose test joint 8 having various sized-pipe sections 9 corresponding to various BOP rams can be used, connected to the drill-pipe connector 7 at the top of the running tool 5 , and connected at the other end to the drill string of drill pipe.
[0026] With the running tool 5 connected to the solid test pin 4 connected to the test plug 25 , the test of the deployed BOP annulars 41 , 42 , fixed rams 45 , 46 , and variable rams 47 , 48 are performed according to rig operating procedures. The annulars and fixed and variable rams seal around the drill pipe or test joint, which is in place for those tests.
[0027] Before testing the BOP blind and shear rams 33 , 34 , which would damage any drill pipe at those locations, the running tool 5 is disconnected from the solid test plug 2 by performing an appropriate number of left-hand turns on the drill string. Because the connection at the primary connector surface 4 is at a low torque relative to the very high torque of standard drill-pipe connections, the disconnection of the running tool from the solid test plug will occur more easily, and before, the loosening of any other connection. The drill string is then raised so that all drill pipe, test joint 8 , and running tool 5 are safely above the level of the blind and shear rams. And then the tests of the deployed BOP blind and shear rams 43 , 44 are performed according to rig operating procedures. The solid test pin 2 remains connected to the test plug 25 , sealing the opening 26 in the test plug, during the BOP blind and shear ram test.
[0028] After completion of the BOP blind and shear ram testing, the drill string with the running tool 5 is slowly and carefully lowered onto the solid test pin 2 still connected to the test plug 25 at the wellhead, and is re-connected by performing an appropriate number of right-hand turns, applying the relatively low torque needed to make the connection. During this process of re-connection, the centralizer 6 keeps the running tool centered in the BOP stack, centered over the solid test pin 2 still connected to the test plug 25 at the wellhead. At the point of re-connection, the large entry bevel 3 on the running tool 5 guides the tool for a proper re-connection.
[0029] After re-connection of the running tool 5 and the solid test pin 2 connected to the test plug 25 , the test plug is un-set from the wellhead and the entire test assembly is pulled out of the hole so that drilling operations can be resumed.
[0030] If the re-connection of the running tool 5 and the solid test pin 2 connected to the test plug 25 is not successfully performed, for whatever reason, the backup secondary retrieval procedure can be performed, in which the running tool is removed from the hole and from the drill string, and standard drill pipe 22 terminating in an emergency retrieval tool 12 , is run into the hole to attach to the secondary connector surface 11 , which also has standard drill-pipe threading 23 with first plug 23 a, and is located in a position where the running tool 5 passes over it, but where the emergency retrieval tool 12 can attach to it. Then the test plug 25 can be un-set from the wellhead and retrieved, allowing drilling options to be resumed.
[0031] The relatively low torque required to make the connection of the running tool 5 to the solid test pin 2 is optimally not greater than 5000 foot-pounds, and the number of turns required to make or unmake the connection is optimally 7 turns.
[0032] Many changes and modifications can be made in the present invention without departing from the spirit thereof. We therefore pray that our rights to the present invention be limited only by the scope of the appended claims. | A blowout-preventer-stack one-trip test tool and method providing a solid test pin for sealing the test plug in the wellhead, a running tool for securely placing, separating from, reattaching, and removing the solid test pin, testing all fixed and variable rams and annulars and testing all blind and shear rams without damage to pipe, in one trip, and a fail-safe secondary provision for removing the solid test plug on a second trip with an emergency retrieval tool if necessary. | 4 |
BACKGROUND
[0001] The invention relates to a retaining device for at least one structural element. In particular the invention relates to a retaining device for an airbag module.
[0002] Among other things, restraint systems for people in motor vehicles include side air bags. Side air bags are usually placed at different points along the longitudinal sides of the vehicle. Currently, there are a number of options for fitting the air bags to the vehicle. For example, the air bag may be integrated into a vehicle door or a vehicle seat. The side air bag may be integrated in the backrest of the seat, and can be fixed to a side strut of the backrest.
[0003] U.S. Pat. No. 5,752,714 (incorporated by reference herein) discloses an option for fastening an air bag to a vehicle backrest. In this, a carrier plate is welded to the round, rod-like strut of the backrest and the air-bag module is fastened on the said carrier plate.
[0004] The known method of fastening the carrier plate has several disadvantages. Costly and complicated welding engineering has to be used in order to install this carrier plate. Should a repair be needed, welding also is required during its removal. In addition, it is not possible to mount the air-bag module and carrier plate in one working step. First, the carrier plate has to be fastened to the seat and only then can the air-bag module be mounted on it.
[0005] If the side strut of the seat does not have a round rod shape and is instead designed as a flat metal plate, welding on the carrier plate and mounting of the air-bag module is even more difficult.
[0006] As a result of the drawbacks of existing arrangements, it is at least one object of the invention to provide a retaining device and a connecting arrangement by means of which a component, in particular an air bag or part of an air bag, can be fastened to a vehicle seat in a simple and cost-effective manner. In addition, a simple method for installing a structural element onto a motor-vehicle component is to be provided.
SUMMARY OF THE INVENTION
[0007] According to an embodiment of the present invention, a retaining device for connecting an airbag module to a motor vehicle is provided. The retaining device includes means for fastening to a motor-vehicle component. These means may comprise at least one hook and at least one element for fastening to the component. The retaining device is connected to the motor-vehicle component via the fastening means.
[0008] According to the present invention, the structural element may be fastened in place on the retaining device before the retaining device is fitted into the vehicle. The preassembled unit of the structural element (e.g., air bag module) and retaining device can therefore be fastened to the motor-vehicle component in a simple manner in one working step. Should repair be needed, this unit can be removed easily and without special assisting means.
[0009] The hook is preferably hooked into a receiving opening of the motor-vehicle component. Installation is completed by fastening the retaining device to the component connection.
[0010] In an embodiment of the retaining device, the element for fastening to the component is an opening formed in the retaining device for receiving and for fitting a screw. The fitting of the device, like the removal, therefore proves to be very simple. However, the opening may also serve as a retainer for a clip by which the retaining device is clipped to the motor-vehicle component.
[0011] There is the option, furthermore, of designing the element for fastening to the component as a connecting part which is fastened on the retaining device. For example, as a clip or as a press-in rivet or press-in screw which is connected to a corresponding structure (screw, etc) of the motor-vehicle component. In this case, the connecting part is preferably of integral design with the retaining device.
[0012] The element for fastening the device to the component motor-vehicle component, is preferably situated in the edge region of the retaining device. This does away with the risk of the structural element, which is connected to the retaining device, protruding over the element and therefore obstructing the installation thereof on the motor-vehicle component.
[0013] The structural element (e.g., air bag module) which is to be connected to the retaining device or the structural element which is held by the retaining device is preferably connected to the said retaining device via a receiving opening. In this case, the retaining device preferably has a receiving region to which the structural element can be fastened in a simple manner. For example, an easily releasable screw connection. However, any means of connecting the structural element to the retaining device lies within the scope of the invention. It is essential only that the two parts can be connected to each other prior to being fitted to a motor-vehicle component.
[0014] The retaining device is preferably essentially of elongated design and is provided with angled portions. As a result, it can be matched to the shape of the motor-vehicle component. The receiving region of the structural element is preferably shaped in such a manner that there is space for receiving a screw connection, for example, between the structural element and retaining device. In addition, the deformation causes the rigidity of the device to be increased.
[0015] The production of the retaining device proves to be cost-effective if, preferably, the hook is of integral design with the retaining device. The preferred material for simple and cost-effective production is sheet metal. However, the retaining device may also be formed as a metal die casting or as a plastic injection molding with inserts. Castings and moldings are very cost-effective to produce. A further advantage of a plastic injection molded part resides in its low weight.
[0016] The embodiments described above are particularly suitable for installation on a vehicle seat, preferably on a strut of the backrest. However, the retaining device may be also installed onto a vehicle door, preferably onto a strut of the vehicle door. The structural element which is to be fastened into place is preferably a side air bag.
[0017] The scope of the invention includes fastening only a portion of an air bag or side air bag to the retaining device. For example a gas-sack-retaining ring, a diffuser, a gas sack and/or a gas generator may be connected the retaining ring. As a result, further elements of an air-bag restraint system may be integrated in other seat components, for example the side strut of the seat.
[0018] The retaining device according to the invention is preferably used for fastening an air bag to a motor-vehicle component, in particular to a vehicle seat or a vehicle door. The air bag may be mounted on the retaining device prior to being fitted. This unit (retaining device and air bag) can be fastened to the seat or to the door and also released with effortless ease and without special assisting means.
[0019] The invention furthermore provides a connecting arrangement having a retaining device according to the invention which additionally also includes the motor-vehicle component. In this case, the motor-vehicle component has at least one receiving opening into which the hook of the retaining device can be hooked.
[0020] A method according to the invention includes fastening a structural element to a retaining device by means of at least one hook and at least one element for connecting the device to the motor vehicle. The method further includes fastening the retaining device to the motor-vehicle component by fitting the hook into a receiving opening of the motor-vehicle component and screwing down the retaining device. This method provides simple, rapid and reversible installation.
[0021] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other features, aspects and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.
[0023] [0023]FIG. 1 is a perspective view of a retaining device according to a first exemplary embodiment of the present invention,
[0024] [0024]FIG. 2 is a perspective view of a retaining device according to a second exemplary embodiment of the present invention,
[0025] [0025]FIG. 3 is a perspective view of a retaining device with a mounted gas-sack-retaining ring with a diffuser according to a third exemplary embodiment of the present invention,
[0026] [0026]FIG. 4 is a perspective view of a retaining device with a mounted gas-sack fastening with a diffuser according to a fourth exemplary embodiment of the present invention,
[0027] [0027]FIG. 5 is a perspective view a side strut of a backrest of a vehicle seat and a retaining device according to the present invention to be fastened thereto,
[0028] [0028]FIG. 6 is a perspective view of a retaining device according to a fifth exemplary embodiment of the present invention,
[0029] [0029]FIG. 7 a is a bottom plan view of a retaining device according to a sixth exemplary embodiment of the present invention,
[0030] [0030]FIG. 7 b is a side view of the retaining device of FIG. 7 a,
[0031] [0031]FIG. 7 c is a side view of the retaining device of FIG. 7 a together with a covering cap,
[0032] [0032]FIG. 7 d is a perspective view from above of the retaining device of FIG. 7 a , and
[0033] [0033]FIG. 7 e is a perspective view from above of the retaining device of FIG. 7 a together with a covering cap.
[0034] [0034]FIG. 8 is a perspective view a side strut and a retaining device similar to the arrangement of FIG. 5, with the retaining device having a hook directed downwards.
DETAILED DESCRIPTION
[0035] [0035]FIG. 1 discloses a first embodiment of a retaining device 1 according to the invention. The retaining device 1 is designed as an elongated metal plate and in addition to a plurality of angled regions has three hooks 21 , 22 , 23 for fitting into elongated holes (not illustrated) of a motor-vehicle component. A hook 23 may be formed on a side arm 12 of the retaining device 1 .
[0036] An opening 3 which is formed in the edge region of the retaining device may be used in conjunction with the hooks 21 , 22 , 23 for fastening the device 1 to the motor-vehicle component by means of a screw connection or another method of fastening.
[0037] Furthermore, installation openings 4 are provided and can be used to fasten an air bag or another structural element to the retaining device 1 , for example via a screw connection. Other methods of fastening may also be used.
[0038] [0038]FIG. 2 discloses a retaining device 1 which is similar to the exemplary embodiment of FIG. 1. The arrangement of the hooks 21 , 22 , 23 in the device of FIG. 2 differs from the hook arrangement shown in FIG. 1. Two hooks 21 , 22 are arranged next to each other. The hook 23 may be situated on the small side arm 12 of the metal plate, the side arm 12 being curved and thereby providing a retainer in which, for example, a gas generator can be mounted. Installation openings 4 are provided in FIG. 2 for the fastening of a structural element.
[0039] [0039]FIG. 3 illustrates a further retaining device 1 having two hooks 2 . The retaining device 1 has a receiving region 10 in which a component 5 is fastened via screw connections or riveted connections. This receiving region 10 is of angled design.
[0040] The component may be an air bag retaining ring 5 with a diffuser which consists of two half shells 51 . The air bag retaining ring 5 is used for securing the air bag, for receiving a gas generator and for directing the gas flow into a preferred discharging direction. Discharge openings (not illustrated) for the discharging gas are formed here in a central region 5 a.
[0041] [0041]FIG. 4 illustrates a further refinement of an air bag retaining ring 5 (also referred to as a sleeve). In this case, the air bag is retained between the sleeve 5 and retaining plate 1 . In addition, the sleeve 5 supports the gas generator and ensures that the gas flow is diverted into a preferred discharge direction. In this case, slots (not illustrated) are provided in the sleeve for the purpose of appropriately discharging the gas if triggered.
[0042] [0042]FIG. 5 shows a side strut 6 of the backrest of a vehicle seat next to a retaining device 1 . The side strut 6 has an opening 8 and a receiving opening 7 . These openings correspond in accordance with the arrows A, B to the opening 3 and the hook 2 of the retaining device 1 . The retaining device 1 contains in turn additional installation openings 4 for the fastening of a structural element.
[0043] Following the installation of a side air bag, the retaining device can be fastened to the side strut or to the struting arrangement of the vehicle door. For this purpose, the hook 2 is inserted into the receiving opening 7 (provided for it) of the side strut 6 . The retaining device 1 is then locked to the side strut 6 via the corresponding openings 3 , 8 by means of a screw connection or another method of fastening.
[0044] [0044]FIG. 8 shows an embodiment similar to the embodiment of FIG. 5. However, in FIG. 8, the retaining device is arranged so that the hook 2 is pointed or directed downwards (i.e. towards the floor of the vehicle) when the retaining device 1 is secured to the side strut 6 . The hook 2 is inserted into the receiving opening 7 along arrow A in FIG. 8. Afterwards, the retaining device 1 is locked to the side strut 6 via corresponding openings 3 , 8 by means of a screw connection or another method of fastening.
[0045] The securing of the retaining device 1 to the side strut 6 with the downwardly pointing hook 2 has the advantage that there is no danger that the retaining device 1 may drop off in case of shock and vibrations and if the screw connection or another fastening of openings 3 , 8 becomes loose. A further advantage is that assembly of the retaining device 1 is simplified as the hook 2 rests against the receiving opening 7 of side the side strut 7 during assembly holding the retaining device 1 in position during fastening.
[0046] The retaining device may have any desired shape. In particular, the device may be formed as a planar sheet-metal element 1 . A correspondingly designed retaining device is illustrated in FIG. 6. Three hooks 2 are arranged in the sheet-metal element 1 . An opening 3 for the screwing to a side strut 6 is formed on an extension 11 of the sheet-metal element 1 .
[0047] [0047]FIGS. 7 a to 7 e illustrate a further retaining device which is designed as a planar element 1 . It has, in the edge region, an opening 3 for fastening to a motor-vehicle component and two hooks 2 which are each arranged on the edge of an essentially square punched opening 2 a . A plurality of installation openings 4 are situated in a receiving region 10 which is angled in the direction of the motor-vehicle component and serves for the fastening of an air-bag module or part of an air-bag module to the retaining device.
[0048] In addition, the device 1 has peripheral hook elements 13 . The hook elements 13 are angled in the direction of the motor-vehicle component and are used for fastening a covering cap 14 to the retaining device. The covering cap corresponds in its shape to the device 1 and has openings 15 in an angled edge region on its periphery. In the exemplary embodiment illustrated, the openings 15 are in each case formed from slots arranged in a U-shape. The slots correspond to the hook elements 13 . The covering cap 14 sits on that side of the device 1 which faces away from the motor-vehicle component.
[0049] After an air-bag module or part of an air-bag module has been fastened to the receiving section 10 the covering cap 14 is fixed in place to form the covering. In this case, both steps may take place prior to the installation of the retaining device. The retaining device may then be connected to a motor-vehicle component via the hooks 2 and the opening 3 .
[0050] The invention is not restricted to the exemplary embodiments illustrated above. One feature for the invention is for a retaining device for at least one structural element which is connected to the retaining device to have means for fastening to a motor-vehicle component, the said means comprising at least one hook and at least one element for fastening to the motor-vehicle component.
[0051] Germany Priority Application 100 65 795.8, filed Dec. 22, 2000 including the specification, drawings, claims and abstract, is incorporated herein by reference in its entirety.
[0052] Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is to be defined as set forth in the following claims. | A retaining device for an airbag module is provided. At least a portion of the airbag module is connected to the retaining device. The retaining device may include a hook and an element for fastening the device to a motor vehicle component. The component may be, for example, a vehicle seat or a vehicle door. The element for fastening the device to the motor vehicle component may include an opening and fastener arrangement or a clip type arrangement. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent Application, Serial No. 10 2010 001 829.5 filed Feb. 11, 2010, pursuant to 35 U.S.C. 119(a)-(d), the content of which is incorporated herein by reference in its entirety as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method for moving a machine element of an automation machine and to a drive system.
[0003] The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
[0004] Machine tools, in particular, are often provided with so-called redundant kinematics. In this case, redundant kinematics are understood as meaning the possibility of moving a machine element, which may be in the form of a tool receiving apparatus or a tool which is clamped in the tool receiving apparatus for example, along a direction with the aid of two separate drive shafts.
[0005] FIG. 1 uses a schematically illustrated machine tool 36 to illustrate the principle of redundant kinematics. A carrier 5 can be moved in a direction X with the aid of two linear motors 3 and 4 . The guidance of the movement in the X direction is ensured by two columns 1 and 2 in this case. A further column 6 which is used to guide the movement of a second linear motor 7 is fastened to the carrier 5 . The linear motor 7 likewise moves in the X direction. The direction of movement of the linear motors 3 , 4 and 7 is indicated by depicted arrows 37 , 12 and 13 . A machine element 8 which is in the form of a tool receiving apparatus within the scope of the exemplary embodiment is fitted to the linear motor 7 . A tool 9 is clamped in the tool receiving apparatus.
[0006] It goes without saying that the machine tool 36 also has further motors which allow a movement of the machine element 8 , for example in the Y and Z directions, but are not illustrated in FIG. 1 for the sake of clarity and since they are irrelevant to understanding the invention.
[0007] In order to measure a first actual variable x c,ist which indicates the position of the column 6 with respect to a stationary machine bed 35 of the machine, the machine 36 has a first measuring device which is not illustrated in FIG. 1 for the sake of clarity. In order to measure a second actual variable x f,ist which indicates the position of the machine element 8 with respect to the column 6 , the machine tool 36 has a second measuring device which is likewise not illustrated in FIG. 1 for the sake of clarity.
[0008] If the machine element 8 is intended to be moved to a particular desired position value in the direction X, the problem arises of how the movement required for this purpose is intended to be divided between the two linear motors 3 and 4 and the linear motor 7 . Since the linear motor 7 must move only small masses (machine element 8 and tool 9 ), it is able to carry out dynamic movements (for example movements with high accelerations) in the X direction, whereas the two linear motors 3 and 4 can carry out only relatively sluggish movements on account of the larger masses to be moved by them. It is therefore expedient to divide the movement of the machine element into a first movement component, which is carried out by the two linear motors 3 and 4 , and a second movement component which is carried out by the linear motor 7 . In this case, the first movement component comprises the movement processes which are not very dynamic, that is to say the low-frequency movement processes, whereas the second movement component comprises the dynamic, that is to say high-frequency, movement processes of the machine element.
[0009] FIG. 2 illustrates a schematic block illustration of a drive system which is known to be commercially available for the machine tool 36 . A desired variable generating unit 15 which is generally part of a control device 14 , which may be in the form of a CNC controller for example, generates a first desired variable x soll which is in the form of a desired position variable within the scope of the exemplary embodiment according to FIG. 1 and indicates the desired position of the machine element 8 with respect to the machine bed 35 . The first desired variable x soll is supplied, as a controlled desired variable for regulating the first movement component of the machine element 8 , to a first regulating means 16 a . The first actual variable x c,ist which is measured using a first measuring device 10 and indicates the position of the column 6 with respect to the machine bed 35 within the scope of the exemplary embodiment according to FIG. 1 is also supplied to the first regulating unit 16 a as a controlled actual variable. The first actual variable x c,ist indicates the first movement component of the machine element 8 by indicating the position of the column 6 with respect to the machine bed 35 within the scope of the exemplary embodiment according to FIG. 1 .
[0010] The first regulating means 16 a drives a first power converter 17 a , which is illustrated by an arrow 18 a in FIG. 2 , in accordance with the first desired variable x soll and the first actual variable x c,ist . The first desired variable x soll is the controlled desired variable for regulating the first movement component of the machine element 8 . The first power converter 17 a accordingly drives the two linear motors 3 and 4 , which is illustrated by an arrow 19 a , the linear motors 3 and 4 moving a load 19 . In this case, the load 19 comprises all elements which are moved by the linear motors 3 and 4 in the direction X. The first regulating means 16 a , the first power converter 17 a , the linear motors 3 and 4 , the load 19 and the measuring device 10 form a first drive shaft 20 a which is used to carry out the first movement component of the machine element 8 .
[0011] In order to regulate the second movement component of the machine element 8 , the so-called contouring error s is determined in the prior art by subtracting the first actual variable x c,ist from the first desired variable x soll using a subtractor 22 . The contouring error s is supplied, as a controlled desired variable for regulating the second movement component of the machine element 8 , to a second regulating means 16 b . The second actual variable x f,ist which is measured using a second measuring device 11 and indicates the position of the machine element 8 with respect to the column 6 within the scope of the exemplary embodiment according to FIG. 1 is also supplied to the second regulating unit 16 b as a controlled actual variable. The second actual variable x f,ist indicates the second movement component of the machine element 8 by indicating the position of the machine element 8 with respect to the column 6 within the scope of the exemplary embodiment according to FIG. 1 .
[0012] The second regulating means 16 b drives a second power converter 17 b , which is illustrated by an arrow 18 b in FIG. 2 , in accordance with the contouring error s and the second actual variable x f,ist . The second power converter 17 b accordingly drives the linear motor 7 , which is illustrated by an arrow 19 b , the linear motor 7 moving a load 21 . In this case, the load 21 comprises all elements which are moved by the linear motor 7 in the direction X. The second regulating means 16 b , the second power converter 17 b , the linear motor 7 , the load 21 and the measuring device 11 form a second drive shaft 20 b which is used to carry out the second movement component of the machine element 8 .
[0013] It is noted at this point that the desired variable generating unit 15 likewise generates corresponding desired values for controlling the movement of the drive shafts which are used to move the machine element in the Y and Z directions. These desired values and the drive shafts which are used to move the machine element in the Y and Z directions are not illustrated in FIG. 2 and the subsequent figures for the sake of clarity and since they are irrelevant to understanding the invention.
[0014] FIG. 3 again illustrates the drive system shown in FIG. 2 in a simplified manner in the form of a block function diagram. In this case, the same elements are provided with the same reference symbols as in FIG. 2 . In this case, the first drive shaft 20 a has a transfer function G(s) and the second drive shaft 20 b has a transfer function F(s). The overall position x ist of the machine element 8 , that is to say its position with respect to the machine bed 35 (see FIG. 1 ), results from adding the first actual variable x c,ist and the second actual variable x f,ist .
[0015] FIG. 4 illustrates another drive system which is known from the prior art, in which a movement is divided into a first movement component and a second movement component. The embodiment according to FIG. 4 is identical to the embodiment according to FIG. 2 insofar as it relates to the first drive shaft 20 a and the second drive shaft 20 b . In FIG. 4 , the same elements are therefore provided with the same reference symbols as in FIG. 2 . The fundamental difference in the embodiment according to FIG. 4 is that the control device 14 ′ has been extended by a dividing unit 23 in comparison with the control device 14 according to FIG. 2 . The desired variable generating unit 15 generates a desired variable x′ soll , which corresponds to the first desired variable x soll according to FIG. 2 . The dividing unit 23 uses the desired variable x′ soll to determine a first desired variable x c,soll , which is supplied to the regulating means 16 a as a controlled desired variable, and a second desired variable x f,soll which is supplied to the regulating means 16 b as a controlled desired variable.
[0016] FIG. 5 again illustrates the control device 14 ′ and, in particular, the dividing unit 23 in detail, the same elements in FIG. 5 being provided with the same reference symbols as in FIG. 4 . In order to divide the movement, the desired variable x′ soll is filtered using a low-pass filter 24 and the first desired variable x c,soll for the first drive shaft 20 a is generated in this manner. The first desired variable x c,soll is subtracted from the desired variable x′ soll using a subtractor 26 and the second desired variable x f,soll for the second drive shaft 20 b is generated in this manner.
[0017] FIG. 6 illustrates another implementation of the dividing unit, which is known from the prior art, in the form of the dividing unit 23 ′. In FIG. 6 , the same elements are provided with the same reference symbols as in FIG. 5 . The embodiment according to FIG. 6 differs from the embodiment according to FIG. 5 only in that, in order to compensate for the temporal delay in the desired variable x c,soll , as caused by the low-pass filter 24 , the desired variable x′ soll is delayed by a particular time using a delay unit 25 before it is supplied to the subtractor 26 as an input variable.
[0018] FIG. 7 again illustrates the drive system shown in FIG. 6 in a simplified manner. In this case, the same elements are provided with the same reference symbols as in FIG. 6 . In this case, the first drive shaft 20 a has a transfer function G(s) and the second drive shaft 20 b has a transfer function F(s). The overall position x ist of the machine element 8 , that is to say its position with respect to the machine bed 35 , results from adding the first actual variable x c,ist and the second actual variable x f,ist .
[0019] With conventional methods, the overall dynamics of the machine are determined by the regulating dynamics of the sluggish first drive shaft (coarse drive shaft). The potential of the dynamic second drive shaft (fine drive shaft) is thus not fully exploited.
[0020] Relatively large contour errors also generally occur in the known movement dividing methods. Overshooting when the desired variable changes rapidly and contour expansion in the case of circular contours to be traced by the machine element often occur in the known methods, for example.
[0021] An egg-shaped contour thus results from a circular contour to be traced by the machine element, for example.
[0022] It would therefore be desirable and advantageous to provide an improved to obviate prior art shortcomings and to move a machine element of an automation machine having redundant kinematics, during which contour errors of a contour to be traced by the machine element are reduced.
[0023] The contour error is here the difference between a predefined desired contour and the actual contour actually traced by the machine element.
[0024] The invention also makes it possible to increase the dynamics of the movement of the machine element.
SUMMARY OF THE INVENTION
[0025] According to one aspect of the present invention, a method for moving a machine element of an automation machine having a first drive shaft performing a first movement component and a second drive shaft performing a second movement component, wherein the first and second movement components have a common direction and are controlled by separate first and second controllers, includes the steps of supplying to the first controller as a desired control variable a first desired value, supplying to the first controller as an actual control variable a first actual value representing the first movement component, and filtering the first desired variable using a filter having a frequency-dependent transfer function to generate a filtered first desired variable.
[0026] According to one embodiment of the method, the first desired variable represents an overall movement, which is composed of the first and second movement components, and a difference is determined between the filtered first desired variable and the first actual variable, and the difference is supplied to the second controller as a desired control variable for controlling the second movement component.
[0027] According to another embodiment of the method, the first desired variable represents the first movement component, and the filtered first desired variable and a second desired variable are added to form a sum, and a difference between the formed sum and the first actual variable are supplied to the second controller as a desired control variable for controlling the second movement component.
[0028] According to another aspect of the invention, a drive system for moving a machine element of an automation machine includes a first drive shaft moving the machine element with a first movement component and a second drive shaft moving the machine element with a second movement component in a common direction relative to the first movement component. The drive system further includes a first controller controlling movement of the first drive shaft and a second controller controlling movement of the second drive shaft, wherein the first controller receives a first desired variable and a first actual value representing the first movement component as an actual control variable, and a filter having a frequency-dependent transfer function filtering the first desired variable and generating a filtered first desired variable.
[0029] According to one embodiment of the drive system, the first desired variable represents an overall movement, which is composed of the first and second movement components, and a subtractor forms a difference between the filtered first desired variable and the first actual variable and supplies the difference to the second controller as a desired control variable for controlling the second movement component of the second drive shaft.
[0030] According to another embodiment of the drive system, the first desired variable represents the first movement component, an adder adds the filtered first desired variable and a second desired variable to form a sum; and a subtractor then forms the difference between the sum and the first actual variable and supplies the difference to the second controller as a desired control variable for controlling the second movement component of the second drive shaft.
[0031] Advantageously, the frequency-dependent transfer function V(s) of the filter may be for all intents and purposes
[0000]
V
(
s
)
=
1
+
G
(
s
)
-
G
(
s
)
F
(
s
)
,
[0000] wherein G(s) is the transfer function of the first drive shaft and F(s) is the transfer function of the second drive shaft and
[0000] s=j· 2·π· f+σ,
[0000] wherein f is the frequency and j is the imaginary unit and σ is the real part of s, since contour errors which then occur are particularly small.
[0032] The automation machine may be in the form of a machine tool, which typically requires a high degree of precision in the movement of machine elements. However, the invention may also be used in other types of automation machines.
BRIEF DESCRIPTION OF THE DRAWING
[0033] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
[0034] FIG. 1 shows a schematically illustrated known machine tool,
[0035] FIG. 2 shows a drive system which is known to be commercially available,
[0036] FIG. 3 shows a known drive system which is illustrated in a simplified manner in the form of a block function diagram,
[0037] FIG. 4 shows another drive system which is known to be commercially available,
[0038] FIG. 5 shows a known control device,
[0039] FIG. 6 shows another known control device,
[0040] FIG. 7 shows another known drive system which is illustrated in a simplified manner,
[0041] FIG. 8 shows a first embodiment of a drive system according to the invention,
[0042] FIG. 9 shows a block function diagram of the first embodiment of a drive system according to the invention,
[0043] FIG. 10 shows a second embodiment of a drive system according to the invention,
[0044] FIG. 11 shows a block function diagram of the second embodiment of a drive system according to the invention,
[0045] FIG. 12 shows a block diagram showing the regulation of the first drive shaft, and
[0046] FIG. 13 shows a block diagram showing the regulation of the second drive shaft.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0047] Throughout all the figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
[0048] Turning now to the drawing, and in particular to FIG. 8 , there is shown a schematic block illustration of a first exemplary embodiment of the drive system according to the invention. In this case, the drive system according to the invention shown in FIG. 8 corresponds to the drive system known from the prior art according to FIG. 2 , but a filter 27 having a frequency-dependent transfer function V(s) has been inserted according to the invention. In FIG. 8 , the same elements are provided with the same reference symbols as in FIG. 2 . According to the invention, the first desired variable x soll is filtered using the filter 27 and a filtered first desired variable x sollg is determined in this manner. The difference d between the filtered first desired variable x sollg and the first actual variable x c,ist is then determined by subtracting the first actual variable x c,ist from the filtered first desired variable x sollg using the subtractor 22 . The difference d is supplied, as a controlled desired variable for regulating the movement of the second movement component of the machine element 8 , to the second regulating means 16 b.
[0049] FIG. 9 illustrates the block function diagram associated with FIG. 8 . In this case, the first drive shaft 20 a has the transfer function G(s) and the second drive shaft 20 b has the transfer function F(s). The filter 27 has the transfer function V(s). The reference symbols correspond to the elements illustrated in FIG. 8 .
[0050] Temporal variables are designated using lower-case letters within the scope of this application. The Laplace transforms of the temporal variables are each represented with a capital letter below, that is to say the Laplace transform X(s) accordingly results from the variable x(t) which is dependent on time t:
[0000]
X
(
s
)
:=
L
[
x
(
t
)
]
(
s
)
:=
∫
0
∞
x
(
t
)
-
st
t
,
(
1
)
[0000] where
[0000] s=j· 2 ·π·f+σ (2),
[0000] where f is the frequency and j is the imaginary unit and σ is the real part of s.
[0051] The transfer function H(s) of the drive system according to the invention shown in FIG. 9 is thus
[0000]
H
(
s
)
=
X
ist
(
s
)
X
soll
(
s
)
=
(
V
(
s
)
-
G
(
s
)
)
·
F
(
s
)
+
G
(
s
)
.
(
3
)
[0052] A particularly great reduction in the contour errors can be achieved if the transfer function of the filter 27 is selected to be:
[0000]
V
(
s
)
=
1
+
G
(
s
)
-
G
(
s
)
F
(
s
)
.
(
4
)
[0053] When equation (4) is inserted into equation (3), the transfer function H(s) of the drive system is then
[0000] H ( s )= F ( s ) (5),
[0000] that is to say the machine element 8 is moved using the dynamics of the second drive shaft 20 b and the non-dynamic drive shaft, that is to say the sluggish drive shaft 20 a , is apparently no longer present in terms of regulation. If the transfer functions G(s) and F(s) are causal, which is practically always the case, there is always a transfer function V(s) which can be achieved.
[0054] FIG. 12 illustrates a block diagram showing the regulation of the first drive shaft 20 a . Within the scope of the exemplary embodiment, the regulating means 16 a has a position regulator 30 a and a speed regulator 31 a in this case. The first power converter 17 a as well as the two linear motors 3 and 4 and the load 19 are simulated using a simulation function block 33 a . The first actual variable x c,ist is differentiated with respect to time t using the differentiator 32 a and a first actual speed v c,ist is calculated in this manner. The round symbols illustrated in FIG. 12 are each subtractors which subtract one output variable from the other and output the difference. The functions indicated in function blocks (square boxes) are the transfer functions of the function blocks.
[0055] In this case, the index c denotes that it is a parameter of the first drive shaft 20 a . The index c may be superscript or subscript in this case.
[0056] Within the scope of the exemplary embodiment, the following thus results for the transfer function G(s) of the first drive shaft 20 a
[0000]
G
(
s
)
=
X
c
,
ist
(
s
)
X
soll
(
s
)
=
1
1
+
s
1
K
v
c
+
s
2
1
K
v
c
K
r
c
τ
c
+
s
3
1
K
v
c
τ
c
T
m
c
+
s
4
1
K
v
c
T
ers
c
τ
c
T
m
c
,
(
6
)
[0000] where
Kv c is the regulating gain of the position regulator
Kr c is the regulating gain of the speed regulator
T c is the integration time constant of the speed regulator
T ers c is the equivalent time constant of the current control loop
T m c is the mechanical time constant.
[0057] FIG. 13 illustrates a block diagram showing the regulation of the second drive shaft 20 b . Within the scope of the exemplary embodiment, the regulating means 16 b has a position regulator 30 b and a speed regulator 31 b in this case. The second power converter 17 b as well as the linear motor 7 and the load 19 are simulated using a simulation function block 33 b . The second actual variable x f,ist is differentiated with respect to time t using the differentiator 32 b and a second actual speed v f,ist is calculated in this manner. The round symbols illustrated in FIG. 13 are each subtractors which subtract one output variable from the other and output the difference. The functions indicated in function blocks (square boxes) are the transfer functions of the function blocks.
[0058] In this case, the index f denotes that it is a parameter of the second drive shaft 20 b . The index f may be superscript or subscript in this case.
[0059] Within the scope of the exemplary embodiment, the following thus results for the transfer function F(s) of the second drive shaft 20 b
[0000]
F
(
s
)
=
X
f
,
ist
(
s
)
D
(
s
)
=
1
1
+
s
1
K
v
f
+
s
2
1
K
v
f
K
r
f
τ
f
+
s
3
1
K
v
f
τ
f
T
m
f
+
s
4
1
K
v
f
T
ers
f
τ
f
T
m
f
,
(
7
)
[0000] where
Kv f is the regulating gain of the position regulator
Kr f is the regulating gain of the speed regulator
T f is the integration time constant of the speed regulator
T ers f is the equivalent time constant of the current control loop
T m f is the mechanical time constant
D(s) is the Laplace transform of the difference d (see FIG. 8 and FIG. 9 ).
[0060] By inserting equation (6) and equation (7) into equation (4), the transfer function V(s) of the filter 27 is thus:
[0000]
V
(
s
)
=
1
+
s
(
1
K
v
c
-
1
K
v
f
)
+
s
2
(
K
r
c
τ
c
K
v
c
-
K
r
f
τ
f
K
v
f
)
+
s
3
(
τ
c
T
m
c
K
v
c
-
τ
f
T
m
f
K
v
f
)
+
s
4
(
T
erc
c
τ
c
T
K
v
c
-
T
erc
f
τ
f
T
K
v
f
)
1
+
s
1
K
v
c
+
s
2
K
r
c
τ
c
K
v
c
+
s
3
τ
c
T
m
c
K
v
c
+
s
4
T
erc
c
τ
c
T
m
c
K
v
c
.
(
8
)
[0061] The transfer function V(s) can be achieved.
[0062] As seen from equation (8), it is easy to parameterize the filter.
[0063] An effective or very effective filter results depending on how accurately the transfer functions G(s) and F(s), which indicate the transfer response of the respectively associated drive shaft, are set up, with the result that a considerable or very considerable reduction in contour errors is achieved by the invention. If the quadratic and higher-order terms in equation (8) are disregarded, the transfer function V(s) of the filter is
[0000]
V
(
s
)
=
1
+
s
(
1
K
v
c
-
1
K
v
f
)
1
+
s
1
K
v
c
.
(
9
)
[0064] It has been shown that, even if the transfer function of the filter in the simplified form according to equation (9) is selected, there is still a very considerable reduction in contour errors.
[0065] The inverse Laplace transform ( 10 ) is defined as:
[0000]
x
(
t
)
=
L
-
1
[
X
(
s
)
]
(
t
)
:=
1
2
π
j
∮
X
(
s
)
e
st
s
,
t
>
0.
(
10
)
[0066] The so-called convolution rule of the Laplace transform is:
[0000]
L
-
1
[
X
(
s
)
·
Y
(
s
)
]
=
x
(
t
)
*
y
(
t
)
=
∫
0
t
x
(
t
-
τ
)
·
y
(
τ
)
τ
.
(
11
)
[0067] With the aid of equations (10) and (11), the filtered first desired variable x sollg is thus
[0000]
x
soll
g
(
t
)
=
L
-
1
[
X
soll
g
(
s
)
]
(
t
)
=
L
-
1
[
V
(
s
)
·
X
soll
(
s
)
]
(
t
)
=
L
-
1
[
V
(
s
)
]
(
t
)
*
L
-
1
[
X
soll
(
s
)
]
(
t
)
=
L
-
1
[
V
(
s
)
]
(
t
)
*
x
soll
(
t
)
,
t
>
0.
(
12
)
[0068] FIG. 10 illustrates a schematic block illustration of a second exemplary embodiment of the drive system according to the invention. In this case, the drive system according to the invention shown in FIG. 10 corresponds to the drive system known from the prior art according to FIG. 4 , but a filter 27 having a frequency-dependent transfer function V(s) has been inserted according to the invention. In FIG. 10 , the same elements are provided with the same reference symbols as in FIG. 4 . According to the invention, the first desired variable x c,soll is filtered using the filter 27 and a filtered first desired variable x c,sollg is determined in this manner.
[0069] The sum of the filtered first desired variable x c,sollg and a second desired variable x f,soll is then determined and a sum variable sg is determined in this manner. The difference d′ between the sum variable sg and the first actual variable x c,ist is then determined by subtracting the first actual variable x c,ist from the sum variable sg. The difference d′ is supplied, as a controlled desired variable for regulating the second movement component, to the second regulating means 16 b.
[0070] FIG. 11 illustrates the block function diagram associated with FIG. 10 . In this case, the first drive shaft 20 a has the transfer function G(s) and the second drive shaft 20 b has the transfer function F(s). The filter 27 has the transfer function V(s). The reference symbols correspond to the elements illustrated in FIG. 8 .
[0071] Equations (1), (2), (4) and (6) to (9) and the above relevant description relating to the first exemplary embodiment correspondingly apply to the transfer functions G(s), H(s) and to the transfer function V(s) of the filter 27 of the second exemplary embodiment, with the result that at this point reference is made to the description relating to the first exemplary embodiment, in which case x soll (s) should be replaced with x c,soll (s) in equation (6) and D(s) should be replaced with D′(s) in equation (7). D′(s) is the Laplace transform of the difference d′ (see FIG. 10 and FIG. 11 ). The transfer function V(s) of the filter 27 according to FIG. 10 and FIG. 11 (second exemplary embodiment) corresponds to the transfer function V(s) of the filter 27 according to FIG. 8 and FIG. 9 (first exemplary embodiment).
[0072] In accordance with equations (10) and (11), the filtered first desired variable x c,sollg in the second exemplary embodiment is thus:
[0000]
x
c
,
soll
g
(
t
)
=
L
-
1
[
X
c
,
soll
g
(
s
)
]
(
t
)
=
L
-
1
[
V
(
s
)
·
X
c
,
soll
(
s
)
]
(
t
)
=
L
-
1
[
V
(
s
)
]
(
t
)
*
L
-
1
[
X
c
,
soll
(
s
)
]
(
t
)
=
L
-
1
[
V
(
s
)
]
(
t
)
*
x
c
,
soll
(
t
)
,
t
>
0.
(
13
)
[0073] It is noted at this point that the first regulating means 16 a , the second regulating means 16 b , the subtractor 22 and the adder 28 are generally in the form of executable software code which is executed by a single processor or a plurality of processors. In this case, the processors can be physically arranged in an individual component or in different components of the drive system.
[0074] It is also noted at this point that the mathematical derivations cited above were set up for the very general continuous-time case. For the special case of discrete-time systems, the general continuous transfer function V(s) of the filter changes into the discrete-time transfer function V(z=e sT ), where T is the sampling time.
[0075] While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit and scope of the present invention. The embodiments were chosen and described in order to explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. | In a method for moving a machine element of an automation machine with separately controlled drive shafts moving in a common direction, a first controller receives a first desired control variable, which is filtered using a filter having a frequency-dependent transfer function. In one embodiment, first desired control variable represents an overall movement of a machine element. A difference is determined between the filtered first desired variable and a first actual variable, and the difference is supplied as a desired control variable to the second controller for controlling the movement of the second drive shaft. In another embodiment, the filtered first desired variable and a second desired variable are added to form a sum, and a difference between the formed sum and the first actual variable is supplied as a desired control variable to the second controller for controlling the movement of the second drive shaft. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention:
This invention relates generally to a compact fluorescent lamp provided with a screw base, and more particularly, to the disposition of a ballast relative to a winding envelope.
2. Description of the Prior Art:
Fluorescent lamps have been used as a general source of illumination for many years. A fluorescent lamp has high lighting efficiency and a low consumption of electric power in comparison with an incandescent lamp and therefore a compact fluorescent lamp provided on an incandescent lamp base, i.e. an E 26 - type screw base, has been developed. But in order to interchange an incandescent lamp with such a compact fluorescent lamp, it is necessary for the fluorescent lamp to have a folded envelope because, in order to obtain about the same brightness as with an incandescent lamp, it is necessary for the fluorescent lamp's envelope to have a certain minimum length. Such a compact fluorescent lamp is known, for example from U.S. Pat. Nos. 3,953,761 and 4,199,708. Such a fluorescent lamp has a lamp base providing a plurality of screw thread portions, a screw base which is secured to the thread portions of the lamp base, a globe, a partition plate dividing the base side and the globe side, a winding envelope and a ballast provided to the partition plate, in which screw threads are formed on both the lamp base and the screw base itself. However, as the screw base is mounted directly to the lamp base in a conventional lamp, it is necessary for the lamp base to be subjected not only to a torsion moment when attaching to a socket but also to the total weight of the lamp including a heavy ballast, a winding envelope and other equipment attached by way of the partition plate. So it is desirable that the connection between the screw base and the lamp base be modified.
Moreover, in such a fluorescent lamp the ballast and the winding envelope are closely disposed and are covered with the globe so that the temperature of the ballast occasionally reaches around 100° C. The winding envelope is designed to exhibit a maximum luminous efficiency when the coolest wall temperature of the winding envelope is about at 40° C. However, the coolest wall temperature exceeds 40° C. and reaches over 60° C. on account of the radiant heat of the ballast. The luminous efficiency is therefore reduced by about 25% on account of the raising of the coolest wall temperature of the winding envelope. It has been considered to dispose the ballast away from the winding envelope, so as to avoid overheating the winding envelope, but this is undesirable as the fluorescent lamp as a whole then becomes large-sized.
Moreover, according to the lighting direction (i.e. downward lighting with the base-up, upward lighting with the base-down, or side lighting with the base to the side), the coolest wall temperature of the winding envelope will be different. Especially in the case of upward lighting, the coolest wall temperature is most apt to be influenced by the heat of the ballast, and the luminous efficiency shows a declining tendency. Thus, such a fluorescent lamp has the defect of having different luminous efficacies according to the lighting directions.
SUMMARY OF THE INVENTION
Accordingly, one object of this invention is to provide a novel compact fluorescent lamp in which a ballast is disposed between the ends of the winding envelope and a bent part of the winding envelope.
Another object of the invention is to provide a novel compact fluorescent lamp having the same coolest wall temperature of the winding envelope regardless of its lighting direction.
Yet another object of this invention is to provide a novel compact fluorescent lamp maintaining a substantially constant luminous efficiency regardless of its lighting direction.
These and other objects have now been achieved according to this invention by disposing the ballast between the ends and the bent part of the winding envelope described below.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of this invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1 is a longitudinal cross-sectional view of a compact fluorescent lamp of this invention with the base up;
FIG. 2 is a view taken on line II--II of FIG. 1;
FIG. 3 is a longitudinal cross-sectional view of the compact fluorescent lamp of this invention with the base down;
FIG. 4 is a longitudinal cross-sectional view of the compact fluorescent lamp of this invention with the base to the side; and
FIGS. 5 and 6 are modifications of the winding envelope of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein like reference numerals designate identical or corresponding parts through the several views, and more particularly to FIGS. 1, 2, 3 and 4 thereof, a compact fluorescent lamp 1 having a chassis member 2, a lamp base member 3 and a globe member 4, is shown. The chassis member 2 is made of heat proof plastics (i.e. polycarbonate resin) and includes a cylindrical part 5 at one end thereof.
The cylindrical part 5 consists of a plurality of screw thread portions 6 and a straight portion 7 which is formed to one end of the screw thread portions 6. The cylindrical part 5 is formed with opposing longitudinal recesses 9 and longitudinal slot 10 extending along the entire length of the outer surface thereof. Moreover, the top of each of the recesses 9 and the slot 10 are open.
The hemisphere shaped base member 3, having an upper opening 3a and a lower opening 3b, is attached to the cylindrical part 5 of the chassis member 2. The inside surface of the upper opening 3a is provided with opposing projection parts 12 and the attachment of the cylindrical part 5 to the base member 3 is accomplished by positioning the projections 12 of the base member 3 in the recesses 9 of the chassis member 2. An incandenscent lamp screw base 8 i.e. an E - 26 type base is fixed by screwing to the screw thread portions 6 of the cylindrical part 5.
Moreover, the base member 3 is provided with a plurality of arc-shaped openings 3' adjacent the lower peripheral opening 3b. The lower opening 3b of the base member 3 is mounted to the bowl shape globe member 4 which is made of plastics (i.e. polycarbonate) and colored, for example, white. Moreover the globe member 4 has a plurality of openings 4' to flow air near the top thereof. The connection of the base member 3 and the globe member 4 is achieved by cooperating hook portions 13 and 14 provided respectively at the peripheries of the base member 3 and globe member 4.
On the other hand, two arm parts 15 are formed at one end on the cylindrical part 5 of the chassis member 2. A rectangular holding plate 16 is mounted to the top of the arm parts 15. A pair of opposed channel shaped fixing wall members 17 are respectively mounted in the holding plate 16 so as to face each other.
Between these fixing wall members 17, the top of a ballast 18 is positioned and is fixed with its lead wires directed to the base member 3.
A winding envelope 20 is mounted to the holding plate 16 so as to surround the ballast 18. The winding envelope 20 is made by bending a straight glass tube into a U-shape to form a first bent part 20a and a pair of first leg parts 20b, followed by the bending once more of each of the pair of leg parts 20b into second U-shapes to form second leg parts 20c and two pairs of second bent parts 20d. The thus formed winding envelope 20 is of a small and compact shape which may be referred to as a saddle shape envelope.
The holding plate 16 of the chassis member 2 also provides a hook arm member 21 by way of a spreader plate 22 to hold the first bent part 20a of the winding envelope 20 and a maintaining plate 23 having parts 24 to hold both ends 20' of the winding envelope 20. The first bent part 20a of the winding envelope 20 is maintained between the hook arm member 21 and the spreader plate 22. The maintaining plate 23 is formed like a flange having semicircle pieces 24 at both ends thereof and the semicircle pieces 24 hold both ends 20' of the winding envelope 20. Moreover, the holder plate 16 of the chassis member 2 provides a large heat shield plate 25 mounted to the maintaining plate 23 and a small heat shield plate 26 mounted to the spreader plate 22, so as to prevent radiant heat from being conducted directly to the first bent part 20a and the ends 20' of the winding envelope 20.
Reference numerals 30 and 31 respectively refer to a glow starter and a condenser.
The aforementioned ballast 18 is surrounded by the winding envelope 20; that is, the ballast 18 is positioned between the second bent parts 20d and the ends 20' of the winding envelope 20. The distance between the top of the ballast 18 and the ends 20' of the winding envelope 20 is about 10 mm and the distance between the bottom of the ballast 18 and the surface of the second bent parts 20d is about 7 mm.
In FIG. 1 and FIG. 2, the isothermal lines A 1 (50° C.) and A 2 (40° C.) of the temperature surrounding the ballast 18 are shown during downward lighting with the base up. That is, the surrounding temperature below the ballast 18 has tendency to fall even at only a small distance from the ballast 18. Consequently, during downward lighting, the areas the second bent parts 20d have not been influenced by the radiant heat of the ballast 18 and the second bent parts 20d thus possess the coolest wall temperature of about 45° C. for the winding envelope 20.
Conversely when upward lighting with the base-down, the isothermal lines B 1 (60° C.) and B 2 (40° C.) for the surrounding temperature are shown in FIG. 3. Consequently, the surrounding temperature is lowest around the ends 20' and the first bent part 20a. The coolest wall temperature of about 50° C. for the winding envelope 20 is thus near the first bent part 20a.
When side lighting with the base to the side, the isothermal lines C 1 (60° C.) and C 2 (40° C.) of the surrounding temperature are shown in FIG. 4. In this case, the coolest wall temperature of 50° C. for the winding envelope 20 exists near the first bent parts 20a.
When lighting with the base down and the base to the side, the distance between the top of the ballast 18 and the ends 20' of the winding envelope 20 is also about 10 mm and the interval between the bottom of the ballast 18 and the surface of the second bent parts 20d is also about 7 mm.
As already mentioned, as the ballast 18 is surrounded by the winding envelope 20 and as the ballast 18 is positioned between the second bent parts 20d and the ends 20' of the winding envelope 20, the winding envelope 20 comes to have a coolest wall temperature portion regardless of the lighting direction. Once a coolest wall temperature is established on the winding envelope 20, the mercury pressure in the winding envelope 20 is determined by the temperature of that coolest wall temperature of the winding envelope 20. That is, even if there is a portion having a higher temperature than the coolest wall temperature portion of the winding envelope 20, the mercury which is not vaporized in the winding envelope 20 condenses at the coolest wall temperature portion of the winding envelope 20. Consequently, the mercury pressure in the winding envelope 20 is prevented from increasing and is maintained at a desired value. A high luminous efficiency and a high output can thus be maintained regardless of the lighting directions.
Moreover, as the ballast 18 is surrounded by the winding envelope 20, the lamp can be miniaturized by using a narrower spacing between the ballast 18 and envelope 20.
In another embodiment of the invention, the winding envelope may be of a U-shape having a bent part 51 and ends 52 as shown in FIG. 5. Or the envelope may have a spiral bent part 61 and ends 62, shown in FIG. 6.
Obviously, numerous modifications and variations of this invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A compact fluorescent lamp having a chassis member, a screw base screwed to the chassis member, a base member secured to the chassis member, a winding envelope having bent part and both ends oriented to the same direction, a ballast surrounded by the winding envelope and a globe member attached to the base member. The ballast is disposed between the bent part and the ends of the winding envelope so as to provide the winding envelope with a desirable coolest wall temperature. | 7 |
This application is a continuation-in-part of U.S. patent application Ser. No. 09/040,935, filed Mar. 19, 1998, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates generally to a mounting bracket and a supporting brace. More specifically, the invention relates to a bracket for supporting a fixture of a ceiling fan. The bracket can be attached to a brace; such as a telescoping brace, and provide both a locking mechanism and structural reinforcement for the brace.
BACKGROUND OF THE INVENTION
Presently, the National Electrical Code permits ceiling light fixtures up to 50 pounds and ceiling fans up to 35 pounds. However, impending changes to the code will increase the acceptable weight of ceiling light fixtures to 80 pounds and the acceptable weight of ceiling fans to 70 pounds. Although various supports for supporting outlet boxes have been developed, the prior art devices were not designed for supporting the increased loading associated with the heavier lighting fixtures and ceiling fans. Thus, there is a need in the art for structures capable of supporting the heavier lighting fixtures and ceiling fans, especially structures that can be positioned between joists.
Examples of prior art supporting structures are disclosed in the following U.S. Pat. Nos.; 2,925,236 to Cook et al.; 2,945,661 to Appleton; 3,214,126 to Roos; 3,518,421 to Cogdill; 4,037,098 to Kowalski; to 4,050,603 to Harris et al.; 4,538,786 to Manning; Re. 33,147 to Reiker, 4,909,405 to Kerr, Jr.; 5,044,582 to Walters; and 5,303,894 to Deschamps et al.
Thus, there is a continuing need to provide an improved supporting structure, especially for supporting lighting fixtures and ceiling fans weighing up to 80 pounds and 70 pounds, respectively. This invention addresses these needs in the art as well as other needs, which will become apparent to those skilled in the art once given this disclosure.
SUMMARY OF THE INVENTION
One object of the present invention is to provide an improved supporting structure.
Still another object of the invention is to provide a structure for supporting lighting fixtures and ceiling fans, or electrical boxes for supporting fixtures and fans.
Yet another object of the invention is to provide a structure for supporting lighting fixtures and ceiling fans, which are heavier than previously permitted.
A further object of the invention is to provide a bracket for reinforcing a brace.
Still a further object of the invention is to provide a bracket for reinforcing and locking a telescoping brace.
The foregoing objects are basically attained by providing a bracket comprising: a first portion having a first central axis in a first plane and a second central axis extending substantially perpendicular to the first central axis and being in a second plane, first and second sides, each of the first and second sides being spaced from the first central axis and facing outwardly from the first central axis, the first side facing in a first direction substantially perpendicular to the first central axis and the second side facing in a second direction substantially perpendicular to the first central axis and substantially parallel to and opposite to the first direction, the first plane being positioned between the first and second sides, and a third side facing in a third direction substantially perpendicular to both the first and second central axes, the first portion further having a coupling element adapted to attach the bracket to a supported element; and a first extension coupled to the first portion and having fourth and fifth sides, each of the fourth and fifth sides being spaced from the first central axis and facing inwardly toward the first central axis, the fourth side facing in the second direction and the fifth side facing in the first direction, and a sixth side facing in a fourth direction substantially parallel to and opposite to the third direction, the first and fourth sides being separated from the second and fifth sides by the first plane, the sixth side being spaced further from the first central axis than the third side in the third direction, and the first portion and the first extension being integrally formed as a one-piece, unitary member.
The foregoing objects are also attained by providing supporting structure, comprising: a brace having an inside section, an outside section with a pair of vertical portions, and a slot extending through the inside and outside sections; a bracket coupled to the inside section of the brace and to each of the vertical portions of the outside section; and a coupling member attached to the bracket and adapted to secure a supported member against the brace to prohibit relative movement between the brace and the bracket.
The foregoing objects are rather attained by providing a supporting structure, comprising a brace having a hollow, elongated member with a longitudinal axis, an inside section, an outside section, and an elongated slot extending through the inside and outside sections; and a bracket having a first portion positioned within the elongated member and being directly connected to the inside section of the elongated member and a first extension attached to the first portion, extending through the elongated slot, and being directly connected to the outside section of the elongated member, the first portion and the first extension being integrally formed as a one-piece, unitary member, and the first portion further having a coupling element adapted to attach the bracket to a supported element.
The foregoing objects are further attained by providing a supporting structure, comprising: a brace having a hollow, elongated member with a longitudinal axis, an inside section with a horizontal bottom, an outside section with first and second vertical sides, and an elongated slot extending through the inside and outside sections; and a bracket having a first portion with first and second ends and a base, the first portion positioned within the elongated member and the base directly abutting the bottom of the brace, the bracket further having first and second extensions attached to the first and second ends of the first portion, respectively, the first extension being spaced from the second extension in a direction substantially parallel to the longitudinal axis, each of the first and second extensions extending through the elongated slot and having a pair of vertical stiffeners, one of the stiffeners of each of the pair of stiffeners directly abutting the first vertical side of the brace, and another of the stiffeners of each of the pair of stiffeners directly abutting the second vertical side of the brace, and the first portion further having a coupling element adapted to attach the bracket to a supported element
The foregoing objects are still firer attained by providing a supporting structure, comprising: a brace having a hollow, elongated member with a longitudinal axis, an inside section, an outside section, and an elongated slot extending through the inside and outside sections; and a bracket having a first portion positioned within the elongated member and being directly connected to the inside section of the elongated member and a first extension attached to the first portion, the first extension extending through the elongated slot and being directly connected to the outside section of the elongated member, the first portion further having a plurality of coupling elements adapted to attach the bracket to a supported element, each of the plurality of coupling elements being spaced in a first direction substantially parallel to the longitudinal axis.
Other objects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the attached drawings which form a part of this original disclosure.
FIG. 1 is a side elevational view of a brace and a bracket in accordance with the present invention, which is positioned between joists and is supporting an electrical junction box;
FIG. 2 is an enlarged, partial view of FIG. 1 illustrating the brace and bracket in accordance with the present invention, supporting a junction box;
FIG. 3 is a cross-sectional view of the brace and bracket in accordance with the present invention supporting a junction box, taken along line 3 — 3 of FIG. 2;
FIG. 4 is a top-side perspective view of the bracket in accordance with the present invention within one of the telescoping channels of the brace in accordance with the present invention;
FIG. 5 is a top-front-side perspective view of the bracket in accordance with the present invention;
FIG. 6 is a front elevational view of the bracket in accordance with the present invention;
FIG. 7 is a side elevational view of the bracket in accordance with the present invention;
FIG. 8 is a bottom-front-side perspective view of the bracket in accordance with the present invention;
FIG. 9 is a bottom view of the bracket in accordance with the present invention;
FIG. 10 is a cross-sectional view of the bracket in accordance with the present invention taken along line 10 — 10 of FIG. 9;
FIG. 11 is a plan view of an unfolded blank used to form the bracket in accordance with the present invention;
FIG. 12 is a front view of one of the channels of the brace in accordance with the present invention;
FIG. 13 is a side elevational view of one of the channels of the brace in accordance with the present invention;
FIG. 14 is a bottom view of one of the channels of the brace in accordance with the present invention;
FIG. 15 is a plan view of an unfolded blank used to form one of the channels of the brace in accordance with the present invention;
FIG. 16 is a side elevational view of one of the channels of the brace in accordance with the present invention located in a first position with respect to a section of wall board;
FIG. 17 is a side elevational view of one of the channels of the brace in accordance with the present invention located in a second position with respect to a section of wall board;
FIG. 18 is a side elevational view of one of the channels of the brace in accordance with the present invention located in a third position with respect to a section of wall board;
FIG. 19 is a top-front-side perspective view of the bracket in accordance with a second embodiment of the present invention;
FIG. 20 is a front elevational view of the bracket in accordance with the second embodiment of the present invention;
FIG. 21 is a side elevational view of the bracket in accordance with the second embodiment of the present invention;
FIG. 22 is a cross-sectional view of the brace and bracket similar to FIG. 3, but in accordance with the second embodiment of the present invention supporting a junction box;
FIG. 23 is a top-side perspective view of the bracket in accordance with the second embodiment of the present invention within one of the telescoping channels of the brace in accordance with the present invention;
FIG. 24 is a top view of the bracket in accordance with the third embodiment of the present invention;
FIG. 25 is a cross-sectional view of the bracket in accordance with the third embodiment of the present invention taken along line 25 — 25 of FIG. 24; and
FIG. 26 is a side elevational view of the bracket in accordance with the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As seen in FIG. 1, a supporting structure 10 in accordance with the present invention is illustrated. Although supporting structure 10 can be use to support various apparatus, it preferably supports an electrical junction box 12 attached to a ceiling fan or lighting fixture 14 .
Supporting structure 10 includes a brace 20 that is positioned between two joists 22 and a bracket 24 . Junction box 12 is secured to bracket 24 and the location of supporting structure 10 on joists 22 permits junction box 12 to extend through an opening 25 in wall board 26 .
Brace 20 has two telescoping channels 40 and 42 . Channels 40 and 42 are substantially identical to each other except that channel 40 is dimensioned smaller than channel 42 . This permits channel 40 to be received within channel 42 in a telescoping manner, i.e., channel 40 can move relative to channel 42 while being inserted within channel 42 . This feature enables brace 20 to be positioned between joists 22 that are spaced various distances apart. Thus, one brace 20 can be made to accommodate a variety of joist spacing.
Since channels 40 and 42 are substantially identical, only channel 42 will be described in detail. Channel 42 has a telescoping end 44 and an attaching end 46 , and extends along a longitudinal axis 47 . Although channels 40 and 42 can take various shapes, telescoping end 44 has a substantially planar top 48 , two substantially planar sides 50 , and a substantially planar bottom 52 with an elongated slot 54 extending completely through bottom 52 . Each of sides 50 are substantially parallel and are substantially perpendicular to top 48 and to bottom 52 . Top and bottom 52 are substantially parallel to each other and are substantially perpendicular to sides 50 . Additionally, each side 50 has an outer vertical surface 51 , and each bottom 52 has a lower horizontal surface 53 .
Attaching end 46 has a plate 60 and holes 62 extending therethrough to receive mounting fasteners 64 ; such as, mounting screws. Mounting screws 64 rigidly couple brace 20 to joists 22 as is known in the art. Once channels 40 and 42 are rigidly secured to joists 22 , channels 40 and 42 are prohibited from moving relative to each other. Preferably, mounting screws 64 are one inch long 12 - 14 type AB threaded tapping screws. A tab 66 extends from the bottom of plate 60 to aid in the positioning of brace 20 relative to wall board 26 .
Since brace 20 can accommodate junction boxes of various shapes and sizes, brace 20 must be capable of being placed at various distances from wall board 26 when junction boxes of various depths are used. As seen in FIGS. 16, if a deep junction box 12 ; for example, 2⅛ inches deep, is used with brace 20 , tab 66 can be spaced from wall board 26 to accommodate this specific junction box. Additionally, tab 66 can be specifically sized to correspond to a junction box 12 of a specific depth. For instance, if a junction box having a depth of 1½ inches is used, tab 66 can be sized so that brace 20 can be positioned such that the bottom of tab 66 is flush against wall board 26 . This facilitates placement of brace 20 on joists 22 for certain sized boxes. Further, tab 66 can aid in the placement of brace 20 when more shallow junction boxes 12 are used. For example, junction boxes 12 that are ½ inch deep. In particular, a score 70 positioned where tab 66 meets plate 60 , enables tab 66 to be broken and separated from plate 60 . Then, channel 42 can be placed flush against wall board 26 .
Tab 66 also has a nailing spur 72 that can be hammered into joist 22 to temporarily support plate 60 against joist 22 while securing plate to joist 22 with mounting screws 64 .
As seen in FIG. 3, channel 40 has a top 78 , two sides 80 , and a bottom 82 with an elongated slot 84 extending therethrough. Also, each side 80 has an inner vertical surface 81 . Channel 40 is substantially identical to channel 42 , except that the sizes and spacing of top 78 , sides 80 , and bottom 82 are changed to allow channel 40 to easily slide within channel 42 . As seen in FIG. 3, when channel 40 is positioned within and received by channel 42 , that portion of channel 40 within channel 42 is completely received within channel 42 .
Channels 40 and 42 are each preferably formed by being folded from a single, unitary member, for example, by being folded from a single, substantially flat blank of material. Blank 90 , as seen in FIG. 15, can be folded to form channel 42 . Since channels 40 and 42 are substantially identical as discussed above, the blank used to form channel 40 is substantially identical to blank 90 , except that the width of the blank may be less than that of channel 42 , to form the smaller top 78 , sides 80 , and bottom 82 . The same blank 90 can be use for both channels 40 and 42 , if channel 40 , i.e., the smaller channel, is folded differently to enable it to be inserted into channel 42 . The different fold for channel 40 would also vary as a result of the different folding. The general use of and folding of blanks to form structures is known in the art. Although any number of materials can be used, preferably, blank 90 is a metallic material; such as galvanized 0.039 sheet steel.
Bracket 24 has a main portion 100 , two extensions 102 , a longitudinal axis 104 in a vertical plane 105 , and a transverse axis 106 in a horizontal plane 107 . Main portion 100 has a top 110 and two pairs of substantially parallel and opposite sides 112 . Top 110 is substantially planar and has two, opposite ends 114 spaced along longitudinal axis 104 . Each side 112 is substantially perpendicular to top 110 and has a vertical surface 113 facing away from longitudinal axis 104 in a direction that is substantially parallel to transverse axis 106 , and a lower horizontal surface 115 facing downwards. Main portion 100 also has coupling elements 116 for connecting with junction box 12 or a fan or fixture bracket. Coupling elements are preferably threaded holes for receiving box mounting screws 118 , although they can be any device to capture the fastening device used to secure junction box 12 to bracket 24 . Preferably, two holes 116 are used to provide a more secure and rigid connection between junction box 12 and bracket 24 . Further, box mounting screws 118 are preferably ¾ inch long 12-24 screws with a lockwasher 120 as seen in FIG. 1 .
Holes 116 are preferably extruded. Although holes 116 are illustrated as extending downwardly in the direction of extensions 102 in, for example, FIG. 6, it may be preferred to form holes 116 extending upwardly, in a direction away from extensions 102 and opposite to the direction illustrated in FIG. 6 .
Extensions 102 are located at each end 114 of main portion 100 . Each extension 102 has an inclined narrow strip 124 that attaches to a bottom 126 , which is substantially planar. Preferably, the inclination of strip 124 relative to longitudinal axis 104 is approximately 45 degrees. Each bottom 126 , in turn, has two substantially parallel sides 128 , which are substantially perpendicular to bottom 126 and extend upwardly. Bottom 126 has an upper horizontal surface 130 and each side 128 has an inner vertical surface 134 , each facing each other.
Bracket 24 , like brace 20 is preferably formed by being folded from a single, unitary member, for example, a substantially flat blank 140 of material. Blank 140 , as seen in FIG. 11, can be folded to form bracket 24 in a manner similar-to the folding of channels 40 and 42 .. Preferably, blank 140 is a metallic material; such as galvanized 0.0625 sheet steel. Thus, blank 140 for bracket 24 is thicker than blank 90 for channels 40 and 42 .
Bracket 24 is sized to fit inside channel 40 in order to act as a lock to stop relative movement of bracket 24 and channels 40 and 42 , while also extending outside channel 42 to help prevent sides 50 from spreading outwardly due to increased downward loading by ceiling fan or lighting fixture 14 . The location of extensions 102 against the outer vertical surfaces 51 provides the mechanism for prohibiting sides of channels 40 and 42 from spreading apart. Additionally, since bracket 24 can be positioned anywhere along brace 20 , this reinforcement of channels 40 and 42 travels to the area of brace 20 where it is needed most.
Accordingly, the distance between outer vertical surfaces 113 of main portion 100 is slightly less than the distance between inner vertical surfaces 81 of channel 40 . Additionally, the distance between inner vertical surfaces 134 of each extension 102 is slightly greater than the distance between outer vertical surfaces 51 of channel 42 . Bracket 24 is sized to easily, but snugly fit with inner channel 40 , and to easily, but snugly receive outer channel 42 .
Also, although main portion 100 of bracket 24 is spaced along longitudinal axis 104 from extensions 102 , the horizontal dimensions of these elements are related to each other to permit insertion of bracket 24 into channel 40 and to permit the insertion of channel 40 and bracket 24 into channel 42 . In particular, each lower horizontal surface 115 of main portion 100 and each upper horizontal surfaces 130 of extensions 102 are spaced a distance slightly greater than the combined thickness of bottoms 82 and 52 of channels 40 and 42 , respectively, in a direction substantially perpendicular to longitudinal axis 104 .
The spacing of extensions 102 along longitudinal axis 104 is also important. As seen in FIGS. 1 and 2, extensions 102 are spaced apart a distance greater than the width of junction box 12 . This enables the top 150 of junction box 12 to directly abut lower horizontal surface 53 of channel 42 , or the bottom 82 of channel 40 , or portions of both surface 53 of channel 42 and bottom 82 of channel 40 , depending on how bracket 24 is situated with respect to each channel 40 and 42 . Then, upon the tightening of box mounting screws 118 , bottoms 82 and 52 of channels 40 and 42 are sandwiched between surfaces 115 of sides 112 of bracket 24 and top 150 of junction box 12 . Thus, not only is junction box 12 securely and rigidly connected to bracket 24 and brace 20 , but bracket 24 is prohibited from moving relative to channels 40 and 42 , and is securely and rigidly fixed in a single position. This allows the once adjustable brace 20 and bracket 24 to become a rigid supporting structure 10 for junction box 12 .
The structure and function of junction box 12 is known in the art and therefore will not be described here in great detail. Junction box 12 preferably has mounting screws 152 for mounting lighting fixture or ceiling fan 14 securely thereto. Junction box 12 can be any known junction box; such as that described in U.S. Pat. No. 4,892,211 to Jorgensen. Accordingly, U.S. Pat. No. 4,892,211 to Jorgensen is hereby incorporated herein by reference.
Although supporting structure 10 has many uses, preferably it is used as follows. Main portion 100 of bracket 24 is positioned within channel 40 as seen in FIG. 4 . Main portion 100 of bracket 24 and channel 40 are then inserted into telescoping end 44 of channel 42 so that extensions 102 of bracket 24 remain outside channel 42 as seen in FIG. 3 . At this point, channels 40 and 42 and bracket 24 are snugly interconnected while each is capable of easily moving relative to each in a direction substantially parallel to longitudinal axis 47 .
Junction box 12 is then loosely connected to bracket 24 by mounting screws 118 . Supporting structure 10 is then placed between two joists 22 and channels 40 and 42 are moved relative to each other so that each attaching end 46 and 76 of channels 42 and 40 can abut a joist 22 . The depth of junction box 12 being known, tab 65 is either removed or left in place and the positioning of brace 20 relative to wall board 26 is accomplished in one of the orientations illustrated FIGS. 16-18. Channels 40 and 42 are then rigidly secured to joists 22 by mounting screws 64 .
Once channels 40 and 42 are secured to joists 22 , they do not normally move relative to each other, however, bracket 24 is capable of moving relative to each of the fixed channels 40 and 42 . This enables the precise positioning of bracket 24 , where desired. Then, junction box 12 is rigidly secured to mounting bracket 24 by tightening box mounting screws 118 . Upon tightening screws 118 , top 150 of junction box 12 , bracket 24 , and either one or both of channels 40 and 42 are compressed together to form a rigid assembly. Thus, bracket 24 and junction box 12 are rigidly fixed with respect to channels 40 and 42 and joists 22 .
Although bracket 24 is illustrated and described as being used with telescoping channels 40 and 42 and supporting either a ceiling fan or a lighting fixture 14 , it should be understood that bracket 24 can be used with structures other than telescoping channels, and can support apparatus other than ceiling fans and lighting fixtures For example, bracket 24 can be used with a single, fixed channel and can support any appropriately sized item intended to be supported by that fixed channel.
Additionally, bracket 24 can be positioned anywhere along channels 40 and 42 . For example, bracket 24 can be positioned entirely on channel 40 , or entirely on channel 42 , or partly on one of channels 40 and 42 and partly on the other of channels 40 and 42 , or entirely on both channels 40 and 42 simultaneously, providing there exists sufficient overlap.
While an advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art from this disclosure that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
FIGS. 19-23 illustrate a second embodiment of the present invention, in the form of bracket 224 . Bracket 224 is substantially identical to bracket 24 except for the absence of sides 112 and the shallower inclination of strips 1124 to accommodate the absence of sides 112 , as seen in FIG. 22 . Bracket 224 has the advantage of being lighter, less expensive, and easier to make than bracket 24 , yet substantially strong to satisfy the appropriate UL testing.
Bracket 224 has a main portion 1100 , two extensions 1102 , a longitudinal axis 1104 in a vertical plane 1105 , and a transverse axis 1106 in a horizontal plane 1107 . Main portion 1100 has a top 1110 which is substantially planar and has two, opposite ends 1114 spaced along longitudinal axis 1104 . Main portion 1100 also has coupling elements 1116 for connecting with junction box 12 or a fan or fixture bracket. Coupling elements are preferably threaded holes for receiving box mounting screws 118 , although they can be any device to capture the fastening device used to secure junction box 12 to bracket 24 . Preferably, two holes 1116 are used to provide a more secure and rigid connection between junction box 12 and bracket 24 .
Extensions 1102 are located at each end 1114 of main portion 1100 . Each extension 1102 has an inclined narrow strip 1124 that attaches to a bottom 1126 , which is substantially planar. Each bottom 1126 , in turn, has two substantially parallel sides 1128 , which are substantially perpendicular to bottom 1126 and extend upwardly.
FIGS. 24-26, illustrate a third embodiment of the present invention in the form of bracket 324 . Bracket 324 is substantially identical to bracket 224 except for the presence of stiffening ribs 2122 in main portion 2100 , and the presence of a third hole 2125 through the center of main portion 2100 , to provide an alternative manner for attaching box 12 to bracket 324 , that is, by a bolt extending through hole 2125 . Thus, bracket 324 can provide stronger, stiffer support then bracket 224 , as needed.
Bracket 324 has a main portion 2100 and two extensions 2102 . Main portions 2100 has a top 2110 , which is substantially planar. Main portion 2100 also has coupling elements 2116 for connecting with junction box 12 or a fan or fixture bracket. Coupling elements are preferably threaded holes for receiving box mounting screws 118 , although they can be any device to capture the fastening device used to secure junction box 12 to bracket 24 . Extensions 2102 are located at each end 2114 of main portion 2100 . Each extension 2102 has in inclined narrow strip 2124 that attaches to a bottom 2126 , which is substantially planar. Each bottom 2126 , in turn, has two substantially parallel sides 2128 , which are substantially perpendicular to bottom 2126 and extend upwardly.
Again, while an advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art from this disclosure that various changes and modifications can be made therein without department from the scope of the invention as defined in the appended claims. | A supporting structure, including a bracket brace and a bracket is disclosed. Preferably, the brace has an inside section and an outside section that move relative to each other. A portion of the inside section can be positioned completely within the outside section and each of the inside and outside sections have a pair of vertical portions. The brace also has a slot extending through the inside and outside sections. The bracket is coupled to the inside section of the brace and to each of the vertical portions of the outside sections of the brace. The bracket also has a coupling members in the form of threaded openings to secure a supported member; such as an electrical junction box, against the brace to prohibit relative movement between the brace and the bracket. The brace and bracket allow new, heavier lighting fixtures and ceiling fans to be safely supported. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application, pursuant to 35 U.S.C. 111(b), claims the benefit of the earlier filing date of provisional application Serial No. 60/299,396 filed Jun. 19, 2001, and entitled “Interchangeable Coiled Tubing Support Block.”
FIELD OF THE INVENTION
[0002] The present invention relates to coiled tubing handling equipment for use in drilling, production, and servicing of wells used for production of petroleum products. The invention is used on wheel type coiled tubing injectors that are used to insert and withdraw coiled tubing from wells.
BACKGROUND OF THE INVENTION
[0003] When continuous coiled tubing is to be used in a well as a service tubing string, a production string, or a drill string, it must be taken from a reel, forced into the well, manipulated, withdrawn from the well, and stored back on its reel. Generally the well is either under or potentially under some pressure, so that the friction of a sealing gland or blowout preventer at the top of the wellhead must be overcome. Further, well pressure may strongly resist insertion of the tubing into the well. While the tubing is being recovered from the well, the weight of the tubing must be lifted from the well. Additionally, there may be substantial friction between the coiled tubing and the well tubing or casing to be overcome while the coiled tubing is in the well, particularly if the well is deviated from vertical. For these reasons, means have been developed to apply axial thrusts to the string of coiled tubing at the wellhead. These means are commonly termed coiled tubing injectors in the oilfield industry.
[0004] Two basic types of coiled tubing injector are used. The first and most common type consists of opposed tracks analogous to the tracks on a crawler tractor, which clamp and thereby grip the tubing between the tracks so that the tracks can transmit axial loadings into the tubing by friction. This track-type type of injector is manufactured and sold by Hydra-Rig, Inc. and others. U.S. Pat. Nos. 3,258,110, 5,188,174, 5,309,990, and 5,975,203 show track-type injectors.
[0005] The second type of tubing injector uses a wheel with opposed pinch rollers, which force the tubing against the rim of the wheel. When torque is applied to the wheel, frictional shear forces cause axial loads to be transmitted to the tubing. This wheel-type of injector is manufactured and sold by Coiled Tubing Systems and Vita International, Inc. U.S. Pat. Nos. 4,673,035 and 5,765,643 show examples of this type of injector system.
[0006] A serious problem, which arises with the use of coiled tubing for both types of tubing injectors is related to progressive cross-sectional ovaling as a consequence of repeated bending beyond the yield point of the tubing material. This undesirable effect may be minimized, given that other design factors are constant, by providing grooved contact surfaces, which closely conform to the tubing diameter.
[0007] U.S. Pat. Nos. 3,754,474, 5,094,340, 5,853,118, and 6,189,609 show means for supporting the tubing for track-type injectors. Initially, some designers used separate sets of drive chain-mounted blocks for each tubing size, each set being grooved specifically to fit a given tubing size. U.S. Pat. No. 3,754,373 relies upon an elastomeric pad with embedded gripper studs on the face of the individual drive chain-mounted blocks. For this configuration, the elastomer deforms to accommodate the particular tubing which it contacts. U.S. Pat. Nos. 5,094,340 and 5,853,118 use a Vee groove block which reduces the cross-sectional bending stresses relative to those of a single contact line block by providing two lines of contact approximately 90° apart. The advantage of a Vee groove block is that the block can be used with a wide range of tubing sizes. However, if high transverse squeeze is used to enhance the frictional transfer of drive force from the drive chain-mounted blocks to the tubing, excessive ovaling may occur with Vee grooves. Shaaban et al. in U.S. Pat. No. 6,189,609 B1 shows an insertable gripper block made of resilient material for use with composite coiled tubing fabricated from plastics and reinforcing fibers. This particular arrangement has the gripper block material selected for its high friction against the tubing and its relatively less aggressive wear tendencies when contacting the soft tubing. Gipson in U.S. Pat. No. 4,673,035 discloses a wheel-type injector, which uses a permanent rubber insert on the wheel perimeter to support the tubing. As configured, the system would possibly require a different wheel for at least some of the currently available coiled tubing sizes and the rubber insert on the wheel perimeter is subject to wear.
[0008] For track-type coiled tubing injectors, the changing of the blocks that will contact the tubing is expensive due to the amount of equipment down time required. For wheel-type injectors, the interchange of drive wheels to accommodate different tubing sizes is also very time consuming and additionally requires lifting equipment. However, larger coiled tubing with its more severe bending cycles and higher squeeze loads coupled with higher radial loads from increased tension for wheel-type injectors in the injector necessitate better cross-sectional support for the tubing.
[0009] While operational time savings are important for operators of wheel-type injectors, weight reduction for the overall system is also important for reducing operating costs and permitting larger tubing loads with the rig. Coiled tubing rig weights are limited by regulations on vehicle weight and bridge load capacities. The use of light weight alloys, such as aluminum, for the relatively large rim portion of a wheel-type injector would appear advantageous, but the very poor wear properties of aluminum and other light metals preclude their use for pipe contact. The portion of the wheel system which contacts the tubing must be able to resist wear while offering good frictional properties even when the tubing has residual water, drilling mud, or petroleum products on its surface.
[0010] Thus, a need exists for a wheel system for wheel-type coiled tubing injectors that have a light weight, robust, and wear resistant means of contacting and fully supporting the tubing while, at the same time, offering the advantages of quick adaptation for other sizes of tubing.
SUMMARY OF THE INVENTION
[0011] The invention contemplates a simple, inexpensive device for solving the problems and disadvantages of the prior approaches discussed above. The present invention includes an interchangeable coil tubing support block that provides a means for quickly adapting a wheel system for wheel-type coiled tubing injectors for a wide variety of tubing sizes.
[0012] In accordance with one aspect of the invention is a drive wheel assembly for use in a wheel-type coiled tubing injector comprising: a drive wheel with a concentric axis of rotation and a rim having an annular groove; a number of carrier blocks having an upper side and a lower side, where the lower side is attached to the annular groove of the rim of the drive wheel; and a number of insert blocks, where each insert block has a first side selectably securable to the upper side of a corresponding carrier block and an opposed side having an arcuate surface for supporting a portion of coiled tubing in contact with the arcuate surface.
[0013] In accordance with another aspect of the invention is a drive wheel assembly for use in a wheel-type coiled tubing injector comprising: a drive wheel having a concentric axis of rotation and a rim having an annular groove; a carrier block having a stepped flat on a lower side, the stepped flat mates with the groove of the rim of the drive wheel, and an upper side comprising a semicylindrical groove along a length of the upper side, said semicylindrical groove has a transverse shouldering groove approximately midway along the length of the upper side of the carrier block, wherein multiple carrier blocks form a continuous array around the circumference of the rim; an insert block having a semicylindrical exterior that mates with the semicylindrical groove of the carrier block, said semicylindrical exterior having a central upset portion that fits into the shouldering groove of the carrier block, and an arcuate interior for supporting a portion of a coiled tubing, wherein the radius of the arcuate interior is selected to correspond to the radius of the coiled tubing to be supported by the arcuate interior; and an attachment element for reversibly attaching the insert block to the carrier block.
[0014] The foregoing has outlined rather broadly several aspects of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed might be readily utilized as a basis for modifying or redesigning the structures for carrying out the same purposes as the invention. It should be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The novel features which are believed to be characteristic of the invention, both as to its organization and methods of operation, together with the objects and advantages thereof, will be better understood from the following description taken in conjunction with the accompanying drawings, wherein:
[0016] [0016]FIG. 1 is an oblique view of a wheel from a wheel-type coiled tubing injector showing the mounting of the carrier blocks and the insert blocks;
[0017] [0017]FIG. 2 shows the end view of a carrier block with an insert block installed;
[0018] [0018]FIG. 3 illustrates a side view of the carrier block with installed insert block of FIG. 2;
[0019] [0019]FIG. 4 illustrates a longitudinal cross-section of the carrier block with installed insert block of FIG. 2;
[0020] [0020]FIG. 5 shows an oblique exploded view of a carrier block and insert block with the retention screws used to hold the insert block in place;
[0021] [0021]FIG. 6 shows an oblique exploded view of the carrier block and insert block of FIG. 5 where the internal arcuate surface has a plurality of holes; and
[0022] [0022]FIG. 7 is a transverse section through the middle of a carrier block and insert block installed on a wheel-type coiled tubing injector.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention provides a simple, inexpensive interchangeable coiled tubing support block that provides a means for quickly adapting wheel-type coiled tubing injectors wheel systems to handle a wide variety of tubing sizes.
[0024] Referring now to the drawings, and initially to FIG. 1, it is pointed out that like reference characters designate like or similar parts throughout the drawings. The Figures, or drawings, are not intended to be to scale. For example, purely for the sake of greater clarity in the drawings, wall thickness and spacing are not dimensioned as they actually exist in the assembled embodiment.
[0025] A typical drive wheel assembly 10 for a wheel-type coiled tubing injector is shown in FIG. 1. The assembly consists of a basic drive wheel 11 having an annularly grooved rim 12 , multiple radial spokes 13 , and mirror-image hub sections 14 . Each hub section 14 has an outward facing mounting flange 15 transverse to the axis of wheel 11 and having a bolt circle. Comating stub shafts 17 are each provided with a concentric transverse flange having a bolt circle corresponding to that of the hub sections 14 . Multiple bolts with nuts 16 are used in the bolt holes of the stub shafts 17 and hub sections 14 to connect the pieces. In operation, the stub shafts 17 are supported by bearings and other structure s approximating those shown in Gipson U.S. Pat. No. 4,673,035. Such support structure is not shown or discussed here, as it is not part of this patent. Multiple bolt holes 18 parallel to the axis of wheel 11 and penetrating both transverse sides of rim 12 are arranged in pairs around the rim of the wheel. Each pair of bolt holes is used to support a carrier block.
[0026] Annular sprockets 20 are attached, using through bolts 19 with nuts, on each of the outer sides of the rim 12 of wheel 11 . Sprockets 20 are provided with through bolt holes for mounting to wheel 11 and are separated into arcuate segments for ease of handling. The through bolts 19 pass through the bolt holes of the sprocket 20 on a first transverse side of rim 12 , through the coaxial corresponding bolt holes 18 of wheel 11 parallel to the wheel axis on both transverse faces of the rim, and then through the bolt holes of the other sprocket on the second transverse side of the rim.
[0027] Referring to FIG. 1, multiple carrier blocks 25 , shown in detail in FIGS. 2 - 5 , are mounted in the annular groove of rim 12 of wheel 11 . For clarity in FIG. 1, two of the carrier blocks have been removed from the rim 12 of wheel 11 , along with three of the four bolts with nuts 19 , and one of the insert blocks is removed from an in-place carrier block. The carrier blocks 25 have double symmetry about two of their median planes. The sides of carrier blocks 25 are flat and parallel, while the bottom surfaces are normal to the sides and consist of stepped flats. The central flats have a width and depth so that they serve to centralize the carrier blocks in the annular groove of rim 12 of wheel 11 . The upper surfaces of the carrier blocks are flat and transverse to the sides and with central semicylindrical grooves 27 running the length of the carrier blocks. In the middle of the groove 27 of the carrier blocks 25 is a transverse coaxial semicylindrical shouldering groove 28 . Transverse to the sides of each carrier block are two through holes 29 symmetrical about the center of the block and close to the bottom of the block.
[0028] These holes 29 can be aligned with the pairs of bolt holes 18 of the rim 12 of wheel 11 and the corresponding bolt holes of sprockets 20 so that bolts with nuts 19 can be used both to retain the sprockets and to also structurally mount the carrier blocks 25 . In the middle of each of the sides of the carrier blocks near the upper edge is a transverse drilled and tapped through hole 30 , as can be seen in FIG. 5. These holes 30 are coaxial and intersect with the groove 28 . A dog point or half dog point set screw 31 is screwed into each hole 30 . The material used for carrier blocks 25 preferably will be aluminum in order to minimize overall structure weight.
[0029] Multiple, interchangeable insert blocks 35 have a semicylindrical exterior 36 with a central upset portion 37 , which has, transverse shoulders on both sides. As shown in FIG. 5, the length of an insert block 35 is the same as that of a carrier block 25 , and the length of the central upset 37 is selected to be a close fit to the shouldering groove 28 . In the middle of the central upset and offset from the diametral 25 plane which defines the flats for the semicylinder of insert block 35 are external coaxial retainer holes 38 . One retainer hole 38 is located on each side of the insert block. The retainer holes 38 are coaxial with the transverse drilled and tapped holes 30 of the carrier block 25 when the insert block 35 is nested into the carrier block 25 . The interior tubing support surface 40 of insert block 35 is a U-shaped arcuate surface having a radius in the bottom of the U corresponding to a preselected size of coiled tubing plus a small clearance to allow for tubing size variations, ovaling, and pressure expansion. The radius of the arc of the U-shaped arcuate surface 40 corresponds to the radial distance from the axis of wheel 11 which it would have when the insert block 35 is mounted in a carrier block 25 which is in turn mounted on rim 12 of wheel 11 . The material used for the insert blocks is selected for wear resistance and strength and, additionally, for having a relatively high friction coefficient with the tubing material. Typically, the insert block material would be a high strength low alloy steel or ductile iron or austempered ductile iron. For cases where very high axial loads are required in the coiled tubing, tungsten carbide grit or similar friction enhancing materials may be emplaced on the arcuate surface 40 of insert blocks 35 by means of flame spraying or other suitable means. Alternatively, the arcuate surface 40 may have a plurality of holes to assist in gripping the tubing.
OPERATION OF THE INVENTION
[0030] The wheel assembly 10 has the wheel 11 with the stub shafts attached by means of bolts and nuts 16 permanently mounted in the set of support bearings of a wheel-type coiled tubing injector assembly, such as that shown in Gipson U.S. Pat. No. 4,673,035. Both the carrier blocks 25 and sprockets 20 are structurally attached to the rim 12 of wheel 11 by means of bolts with nuts 19 mounted through bolt holes 18 . Each of the insert blocks 35 for a given size of coiled tubing is positioned and structurally supported in a carrier block 25 and retained therein by means of screws 30 engaging retainer holes 38 . For a mated carrier block 25 and insert block 35 , the shoulders of the central coaxial semicylindrical groove 28 of carrier block 25 serve to transfer tangential forces to the insert block 35 through the comating shoulders of central semicylindrical upset 37 on the exterior of the insert block. The insert blocks 35 thus present a nearly continuous grooved surface of constant groove radius to the tubing which engages the wheel 11 . The size of the gaps between the individual insert blocks is selected to be insufficient to distress the tubing by causing local intensifications of bending at the gaps.
[0031] When it is desired to change the insert blocks so that a different size of coiled tubing may be accommodated, the individual insert blocks 35 may be released by backing out the screws 30 which retain each insert in its respective carrier block 25 , removing the insert block, replacing the insert block with the new size of insert block, reengaging the screws 30 into the retainer holes 38 of the insert block. As can be seen in FIG. 7, there is sufficient space to access the screws 30 between the sprockets 20 and the side of the carrier blocks 25 .
[0032] Numerous advantages result from the construction of a wheel-type coiled tubing injector disclosed herein. Use of aluminum or other light weight material, rather than steel, for the carrier blocks permits a reduction in overall weight for the entire wheel assembly. The minimization of the size and attendant weight of the interchangeable portion of the wheel assembly when reconfiguring the wheel for a different tubing size greatly eases the operator effort and time needed for such an operation. The use of the insert blocks with the carrier blocks allows the minimization of the size and weight of the interchangeable elements. The use of aluminum for a unitized block is unsatisfactory because of the poor wear properties of the material. However, the configuration of this invention permits selecting optimal properties for the insert block so that wear and frictional properties can be much improved when compared to an unitized aluminum block. Flame sprayed or similarly applied friction enhancement material is readily applied to ferrous metals, but generally is unsuited for application to aluminum because of its surface chemistry and its high flexibility and attendant inability to provide good structural support for hardfacing relative to ferrous metals. As a consequence of the construction of this invention, operational economies are available as a result of reduced changeover time for different tubing sizes. The reduction in weight for the wheel system in turn permits more capacity on the storage reel for the coiled tubing rig.
[0033] As will be understood readily by those skilled in the art, various changes in the configuration of this invention can be made without departing from the spirit of the invention. For example, the wheel and carrier blocks could interface differently, and the insert blocks could be shaped differently on the exterior. | The present invention includes an interchangeable coil tubing support block that provides a means for quickly adapting a wheel system for wheel-type coiled tubing injectors for a wide variety of tubing sizes. In addition, the present invention provides a light weight, robust, and wear resistant means of contacting and fully supporting the tubing while it is being injected into and withdrawn from a well. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to an improved foundry binder composition for ambient temperature curing, and especially for alkaline aggregates such as reclaimed sand, Olivin sand, alumina sand, etc.
Conventional foundry binders for ambient temperature curing are classified under two types; one is inorganic binders, typified as water glass, and the other is organic binders, such as the acid curing type and urethane forming type. While inorganic binders scarcely impair the environment of workshop because then emit few toxic gases when used, the molds obtained therefrom are poor in the shake-out property after pouring. Thus, difficulties in the shake-out property reduce the availability of utilization of the reclaimed sand.
On the other hand for organic binders, acid-curing binders made of phenolic resins and furan resins require large quantity of strong acids at the curing thereof, and this causes corrosion on the equipment, and an irritant gas at pouring is emitted, although these binders are excellent in the shake-out property of the molds therefrom.
A method of ambient-temperature-curing is known for producing foundry molds with a binder system comprising the reaction of polyols of a phenolic resin or an oil modified alkyd resin with a polyisocyanate in the presence of liquid amines or metal naphthenates, and this method is useful in a large dimensional molding with compact equipment. However, since this method necessitates a long curing time, it cannot be employed for a commercial stage production of the molds.
A method for commercially producing foundry molds under ambient-temperature-curing is called "gas-curing mold forming process", which allows a high productivity with a rapid mold forming cycle by passing gaseous amines into a mixture of foundry aggregates in the presence of both a phenolic resin as a polyol component and a polyisocyanate. This system is widely used into the foundry industries because of its energy-saving. However, when highly alkaline sand typified as reclaimed sand, Olivin sand, alumina sand, etc. having the pH value of 7 or more, is employed as foundry aggregates, even in coating thereof with a binder, the obtained coated sand is often so degraded that it is useless in mold forming because a prior reaction of the phenolic resin with the liquid polyisocyanate of binder components. This occurs by means of a catalytic behavior of said alkaline composition in silica sand.
This is an accelerated urethane forming reaction affecting flow of obtained coated sand, and this fails in smoothness of mold surface as well as strength of the molds obtained therefrom. Therefore, cast articles made of said molds are likely to have defects such as an irregular surface, occlusion of sand thereinto, etc. Said degradation often occurs during a hot-humid summer season, at excessively elevated temperature of sand, or in a high content of said alkaline composition in silica sand. This results in the fact that said urethane forming reaction depends on temperature as well as an existing quantity of catalytic substances. So, to suppress said urethane forming reaction, a method is known to incorporate an acidic substance into a phenolic resin component of binders for neutralizing said alkaline composition of silica sand. However, when said acidic substance is short of the neutralizing equivalent, it is not effective. On the contrary, when it is excessive, said phenolic resin component spontaneously give rise to a condensation reaction which enables the component to be useless as a binder. There is a method by incorporating said acidic substance into a liquid polyisocyanate component of binders, however, in the method the activated hydrogen of said acidic substance reacts with isocyanate groups which results not only in a poor reactivity thereafter, but, an inert precipitation occurs at mixing with a phenolic resin component.
A method is also known that a small quantity of said acidic substance is directly incorporated into a mixer when coating sand with both a phenolic resin and a liquid polyisocyanate component. However, this method requires additional equipment, and the operation therefor becomes complicated. Furthermore, this method is essentially difficult in mixing as dispersing small quantities of said acidic substance homogeneously in a large quantity of formulation is not a practical solution.
The present invention results from an investigation to overcome these drawbacks. The inventors have found that the incorporation of a substance that will emit an acid upon hydrolysis will neutralize the alkaline components present.
SUMMARY OF THE INVENTION
This invention is concerned with a foundry binder compositions for ambient temperature curing, with special emphasis upon alkaline aggregates such as reclaimed sand, etc. A binder system curable by gaseous amines, contains phenolic resin, polyisocyanate and a hydrogen chloride emitting substance upon hydrolysis. This hydrogen chloride emitting substance is selected from: ##STR2## wherein R 1 , R 2 , R 3 , are selected from hydrogen, chlorine, alkyl, vinyl or alkoxy, or
thionyl chloride, sulfuryl chloride, acid chlorides of sulfur, such as methyl chlorosulfuric acid, ethyl chlorosulfuric acid, etc.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a foundry binder composition employed for mold forming comprising a phenolic resin with a liquid polyisocyanate cured under a gaseous amine, wherein a potentially hydrogen-chloride-emitting substance at hydrolysis is present. An object of the present invention is to enable said substance to emit hydrogen chloride at hydrolysis due to moisture contained in air or the silica sand during mixing. An additional object of the present invention is to suppress the urethane forming reaction of coated sand prior to mold forming by neutralizing an alkaline composition of silica sand with emitted hydrogen chloride so that it can suppress degradation of binder components as much as possible.
Phenolic resins hereof are any of the following three types of phenolic resins which are employed either independently or jointly; a novolac type phenolic resin, a resole type phenolic resin and a benzylic-ether type phenolic resin. Above all, a benzylic-ether type phenolic resin is preferable. The inventors hereof will explain each embodiment for preparing these phenolic resins as follows:
(a) a novolac type phenolic resin hereof is prepared by reacting phenols with aldehydes in the presence of inorganic acids such as hydrochloric acid, sulfuric acid, etc., or organic acids such as para-toluene sulfonic acid, oxalic acid, etc.
(b) A resole type phenolic resin hereof is prepared by reacting phenols with aldehydes in the presence of basic substances such as ammonia, and either oxides or hydroxides of alkali metals.
(c) A benzylic-ether type phenolic resin hereof is prepared by reacting phenols with aldehydes within the pH value range of 4 to 7 in the presence of naphthenates, carboxylates, and/or either oxides or hydroxides of divalent metals. If necessary, carboxylic acids or hydrochloric acid, etc. May be added thereto. The resin obtained is identified by an absorption of benzylic-ether linkage at 1060 cm -1 in an infra-red spectrometry.
Phenols used herein are phenol, or alkyl phenols such as cresol, xylenol, etc., or a mixture thereof.
Aldehydes used herein are formalin, paraformaldehyde, or formaldehyde-emitting substances such as trioxane, or a mixture thereof.
Phenolic resins used herein are preferably prepared in a homogeneously dissolved form of an inorganic solvent so that the viscosity thereof is adjusted to be 10 poise at 25° C. or less.
Usable organic solvents used herein are alcohols, ketones, esters, aromatic hydrocarbons, and a mixture thereof, however, those having a high boiling point are preferable in the present invention because of suppressing degradation of coated sand obtained.
Liquid polyisocyanates used herein are any of aliphatic, alcyclic or aromatic polyisocyanates having at least two isocyanate groups therein, preferably diphenylmethane diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenylisocyanate, and/or a mixtures thereof. Alternatively, the polyisocyanate can be dissolved in an aromatic solvent for ease of incorporation.
Gaseous amines employed herein for a reaction catalyst of binder components, phenolic resin and liquid polyisocyanate, are methyl amine, dimethyl amine, trimethyl amine, ethyl amine, diethyl amine, triethyl amine, dimethyl ethyl amine, etc. The incorporating proportion ranges of both a liquid polyisocyanate and an amine to 100 parts of a phenolic resin as its solid content are 18 to 550 parts by weight of a polyisocyanate, and 2.5 to 125 parts by weight of an amine, respectively. However, 90 to 365 parts of a polyisocyanate and 7.5 to 75 parts by weight of an amine, are the preferred proportion.
Hydrogen-chloride-emitting substances at hydrolysis according to the present invention to suppress the degradation of coated sand have the following each generic formula:
(a) Silanes ##STR3## where, R 1 , R 2 , R 3 are selected from hydrogen chlorine, alkyl group, vinyl group, and alkoxy group, and they are either identical or different.
(b) Thionyl chloride, sulfuryl chloride, acid chlorides of sulfur such as methyl chlorosulfuric acid, ethyl chlorosulfuric acid, etc., or a mixture thereof.
The proper time for incorporating said hydrogen-chloride-emitting substances thereinto is optional; during preparation of a polyisocyanate, by dissolving same into an organic solvent, or at mold forming. It goes without saying that residual chlorides remaining in polyisocyanate are also inclusive in the present invention. Said hydrogen-chloride-emitting substances at hydrolysis according to the present invention are preferably contained in the liquid polyisocyanate component and the content thereof is so adjusted that the proportion range in 100 parts by weight of said polyisocyanate to said substances is 0.1 to 7 parts by weight, preferably 0.15 to 4 parts by weight. When the proportion range is less than 0.1 parts by weight, there is no effect to suppress said degradation. When it is more than 7 parts by weight, an excessive quantity of hydrogen chloride emitted endangers the environment of workshop and may corrode the facilities thereof.
The sum of incorporating proportion range of a liquid polyisocyanate containing said hydrogen-chloride-emitting substances and a phenolic resin as the solid content to 100 parts by weight of silica sand is 0.1 to 6 parts by weight, preferably 0.2 to 3 parts by weight. When the proportion is less than 0.1 parts by weight, the obtained molds therefrom are poor in strength, and when it is more than 6 parts by weight, this impairs the shake-out property of the molds.
The composition according to the present invention is effective when the pH value of silica sand is less than 7.
The inventors hereof will explain more details of the present invention with the following nonlimitative Examples and Comparative Example, wherein "parts" and "percent" represent "parts by weight" and "percent by weight", respectively.
PREPARATION EXAMPLE 1
Preparation of a phenolic resin
To a four-necked flask with a relux cooler and a stirrer, 1000 parts of phenol, 1500 parts of 37% formalin are charged. After the pH value range thereof was adjusted to 5.0 to 6.0 by adding 6 parts of zinc acetate and 10% sodium hydroxide solution thereinto, the mixture was reacted at 98° to 100° C. for 60 minutes. The reaction was continued until the temperature reached 135° C. under distilling water and unreacted phenol. At 135° C., 1000 parts of xylene and 300 parts of diethyl ketone, pre-mixed, were added thereinto, and the reaction mixture was dissolved by stirring. Then, it was cooled to ambient temperature. A phenolic resin obtained and an absorption of benzylic-ether linkage at 1060 mm -1 identified by an infra-red spectrometry.
Preparation of liquid polyisocyanate A
Into 40 parts of a mixed solution of xylene and mineral spirit (mixing proportion of xylene to mineral spirit was 7 to 3), 100 parts of a polyisocyanate consisting mainly of diphenylmethane diisocyanate were dissolved. After the solution became homogeneous, 1.4 parts of vinyl trichlorosilane were added thereto as a hydrogen-chloride-emitting substance at hydrolysis. Thus, liquid polyisocyanate A was obtained.
Preparation of liquid polyisocyanate B
Into 40 parts of a mixed solution of xylene and mineral spirit (mixing proportion of xylene to mineral spirit was 7 to 3), 100 parts of a polyisocyanate consisting mainly of diphenylmethane diisocyanate were dissolved. After the solution became homogeneous, 1.4 parts of thionyl chloride were added thereto as a hydrogen-chloride-emitting substance at hydrolysis. Thus, liquid polyisocyanate B was obtained.
Preparation of liquid polyisocyanate C
Into 40 parts of a mixed solution of xylene and mineral spirit (mixing proportion of xylene to mineral spirit was 7 to 3), 100 parts of a polyisocyanate consisting mainly of diphenylmethane diisocyanate were dissolved. Thus, liquid polyisocyanate C was obtained.
EXAMPLES AND COMPARATIVE EXAMPLES
For two kinds of sand, reclaimed sand (pH value of 10.7) and Olivin sand (pH value of 9.2), experiments were run, respectively. To 3000 parts of sand in a bench scale whirl-mixer with rotating speed of 150 rpm, 45 parts of said phenolic resin and 45 parts of liquid polyisocyanate A hereof were added. The mixture was further mixed well for 1 minute and coated sand was obtained. Test specimens were prepared with the coated sand according to a method explained later.
The results obtained are shown in Table 1.
Except for changing liquid polyisocyanate A to liquid polyisocyanate B and C, the same formulation and procedures were taken, respectively. The results obtained are also shown in Table 1.
TABLE 1__________________________________________________________________________ Compressive strength of mold (kg/cm.sup.2) Lapse of time from moldingLiquid directly after mixing Lapse of time from mixing to moldingisocyanate Sand Directly 1 hour's 24 hours' 20 minutes' 40 minutes' 90 minutes'employed employed after after after after after after__________________________________________________________________________A Reclaimed 52.2 55.8 63.2 59.3 56.3 50.4 Olivin 53.2 68.3 72.3 67.3 63.1 58.2B Reclaimed 50.4 53.4 60.8 58.1 54.3 48.0 Olivin 52.6 67.3 73.4 67.2 61.5 55.4C Reclaimed 47.3 52.2 57.2 38.2 29.3 15.2(Comparative) Olivin 52.8 68.0 71.4 57.1 44.6 18.3__________________________________________________________________________
As clearly shown in Table 1, the composition according to the present invention have improved properties and results.
TEST METHODS USED FOR TABLE I
Methods for preparing test specimen
Coated sand after lapse of determined time was charged into a mold having 50 mm in diameter and 50 mm in depth. The charged coated sand was rammed until the depth reached 50 mm.
A saturated gaseous triethyl amine was prepared by dried air and a liquid triethyl amine.
The gaseous triethyl amine was passed through the mole for 15 seconds so that molded coated sand was cured. Molded article thus obtained was taken out of the mold and it was employed at test specimen.
Determination of compressive strength
Each test specimen after lapse of determine time was set into an Amsler type universal testing machine, and the compressive strength at breach was determined.
Method for determining pH value
Into 50 g of water 50 g of silica sand was charged. The mixture was stirred well. After it was left still until sand settles, pH value of the upper water phase was determined by a glass-electrode type apparatus. | This invention is concerned with foundry binder compositions for alkaline aggregates such as reclaimed sand, Olivia sand, alumina sand, etc., which cure at ambient temperatures. The binder composition is composed of phenolic resins, polyisocyanates and a hydrogen chloride emitting substance upon hydrolysis. Curing of this composition is by gaseous amines. The hydrogen chloride emitting substance on hydrolysis is selected from the following: ##STR1## wherein R 1 , R 2 , R 3 can be selected from: Hydrogen, Chlorine, alkyl, vinyl or alkoxy, or
(b) Thionyl chloride, sulfuryl chloride, acid chlorides of sulfur, such as methyl chlorosulfuric acid, ethyl chloroculfuric acid. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/951,102, filed Sep. 27, 2004, now U.S. Pat. No. 7,270,811, issued Sep. 18, 2007, which application is a continuation of U.S. patent application Ser. No. 09/573,740, filed May 18, 2000, now U.S. Pat. No. 6,913,922, issued Jul. 5, 2005, which patent claims priority under the provisions of 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 60/134,764, filed May 18, 1999, the entirety of each of which are incorporated herein by this reference.
STATEMENT ACCORDING TO 37 C.F.R. §1.52(e)(5)—SEQUENCE LISTING SUBMITTED ON COMPACT DISC
Pursuant to 37 C.F.R. §1.52(e)(1)(iii), a compact disc containing an electronic version of the Sequence Listing has been submitted concomitant with this application, the contents of which are hereby incorporated by reference. A second compact disc is submitted and is an identical copy of the first compact disc. The discs are labeled “copy 1” and “copy 2,” respectively, and each disc contains one file entitled “Sequence Listing.txt” which is 69 KB and created on Sep. 22, 2004.
TECHNICAL FIELD
The present invention relates generally to the field of gene therapy, particularly gene therapy involving elements derived from viruses, more in particular, elements of adenoviruses.
BACKGROUND
Adenoviruses have been proposed as suitable vehicles to deliver genes to a host. There are a number of features of adenoviruses that make them particularly useful for the development of gene-transfer vectors for human gene therapy.
The adenovirus genome is well characterized. It consists of a linear double-stranded DNA molecule of approximately 36000 base pairs (“bp”). The adenovirus DNA contains identical Inverted Terminal Repeats (“ITRs”) of approximately 90-140 base pairs with the exact length depending on the serotype. The viral origins of replication are within the ITRs exactly at the genome ends.
The biology of the adenoviruses is characterized in detail. The adenovirus is not associated with severe human pathology in immuno-competent individuals. The virus is extremely efficient in introducing its DNA into a host cell; the virus can infect a wide variety of cells and has a broad host-range. The virus can be produced at high virus titers in large quantities.
The virus can be rendered replication defective by deletion of the early-region 1 (E1) of the viral genome (Brody et al., 1994). Most adenoviral vectors currently used in gene therapy have a deletion in the E1 region, where desired genetic information can be substituted.
Based on these features, preferred methods for in vivo gene transfer into human target cells make use of adenoviral vectors as gene delivery vehicles. However, drawbacks associated with the therapeutic use of adenoviral vectors in humans still exist. A major drawback is the existence of widespread pre-existing immunity among the population against adenoviruses. Exposure to wild-type adenoviruses is very common in humans, as has been documented extensively (reviewed in Wadell, 1984). This exposure has resulted in immune responses against most types of adenoviruses, not alone against adenoviruses to which individuals have actually been exposed, but also against adenoviruses which have similar (neutralizing) epitopes. This phenomenon of pre-existing antibodies in humans, in combination with a strong secondary humoral and cellular immune response against the virus, can seriously affect gene transfer using recombinant adenoviral vectors.
To date, six different subgroups of human adenoviruses have been proposed which in total encompasses 51 distinct adenovirus serotypes. (See, Table 1.) A serotype is defined on the basis of its immunological distinctiveness as determined by quantitative neutralization with animal antisera (horse, rabbit). If neutralization shows a certain degree of cross-reaction between two viruses, distinctiveness of serotype is assumed if A) the hemagglutinins are unrelated, as shown by lack of cross-reaction on hemagglutination-inhibition, or B) substantial biophysical/biochemical differences in DNA exist (Francki et al., 1991). The nine serotypes identified last (42-51) were isolated for the first time from HIV-infected patients (Hierholzer et al., 1988; Schnurr et al., 1993). For reasons not well understood, most of such immune-compromised patients shed adenoviruses that were rarely or never isolated from immune-competent individuals (Hierholzer et al., 1988, 1992; Khoo et al., 1995, De Jong et al., 1998).
The vast majority of people have had previous exposure to adenoviruses, especially the well-investigated adenovirus serotypes 5 and type 2 (“Ad5” and “Ad2”) or immunologically related serotypes. Importantly, these two serotypes are also the most extensively studied for use in human gene therapy.
As previously stated, the usefulness of these adenoviruses or cross-immunizing adenoviruses to prepare gene delivery vehicles may be seriously hampered, since the individual to whom the gene delivery vehicle is provided, will raise a neutralizing response to such a vehicle before long.
Thus a need exists in the field of gene therapy to provide gene delivery vehicles, preferably based on adenoviruses, which do not encounter pre-existing immunity and/or which are capable of avoiding or diminishing neutralizing antibody responses.
DISCLOSURE OF THE INVENTION
Thus, the invention provides a gene delivery vehicle comprising at least one Ad35 element or a functional equivalent thereof, responsible for avoiding or diminishing neutralizing activity against adenoviral elements by the host to which the gene is to be delivered and a gene of interest. A functional equivalent/homologue of an Ad35 (element) for the purposes of the present invention is an adenovirus (element) which, like adenovirus 35, encounters pre-existing immunity in less than about 10% of the hosts to which it is administered for the first time, or which is capable in more than about 90% of the hosts to which it is administered of avoiding or diminishing the immune response.
Throughout the world, populations of humans can have varying pre-existing immunity profiles. For the present invention, the gene delivery vehicle of choice is preferably matched with a pre-existing immunity profile for the particular population in that geographic area. Typical examples of such adenoviruses are adenovirus serotypes 34, 26, 48 and 49.
A gene delivery vehicle may be based on Ad35 or a functional homologue thereof, but it may also be based on another backbone, such as that of adenovirus 2 or 5, so long as it comprises at least one of the elements from Ad35 or a functional equivalent thereof, which leads to a diminishment of the immune response against such an Ad2 or Ad5 based gene delivery vehicle. Of course, the gene delivery vehicle may also comprise elements from other (adeno) viruses, so long as one replaces an element that could lead to immunity against such a gene delivery vehicle by an element of Ad35 or a functional homologue thereof, which has less of such a drawback and which, preferably, avoids such a drawback.
In the present invention, a “gene delivery vehicle” is any vehicle capable of delivering a nucleic acid of interest to a host cell. It must, according to the invention, comprise an element of Ad35 or a functional equivalent thereof, which must have a beneficial effect regarding the immune response against such a vehicle. Basically, all other elements making up the vehicle can be any elements known in the art or developed in the art, as long as together they are capable of delivering the nucleic acid of interest. In principle, the person skilled in the art can use and/or produce any adenoviral products or production systems that can or have been applied in the adenoviral field. Typically, the products of the invention can be made in the packaging cells useable with, for example, Ad5, typically the vectors based on Ad35 can be produced and/or used in the same manner as those of other adenoviruses, for example, Ad2 and/or Ad5.
A good overview of the possibilities of minimal vectors, packaging systems, intracellular amplification, vector and plasmid based systems can be found in co-pending, co-owned International Patent Application PCT/NL99/00235 or U.S. Pat. No. 5,994,128 to Bout et al., incorporated herein by reference. Non-viral delivery systems can also be provided with elements according to the invention, as can viral delivery systems. Both kinds of systems are well known in the art in many different set-ups and do therefore not need any further elaboration here. A review on the many different systems and their properties can be found in Robbins and Ghivizzani (1998) and in Prince (1998), also incorporated herein by reference.
Gene delivery vehicles typically contain a nucleic acid of interest. A nucleic acid of interest can be a gene or a functional part of a gene (wherein a gene is any nucleic acid which can be expressed) or a precursor of a gene or a transcribed gene on any nucleic acid level (DNA and/or RNA: double or single stranded). Genes of interest are well known in the art and typically include those encoding therapeutic proteins such as TPA, EPO, cytokines, antibodies or derivatives thereof, etc.
An overview of therapeutic proteins to be applied in gene therapy is listed hereinafter. They include: immune-stimulatory factors like tumor-specific antigens, cytokines, etc.; anti-angiogenic factors, non-limiting examples of which are endostatin, angiostatin, ATF-BPTI CDT-6, dominant negative VEGF-mutants, etc.; angiogenic factors, non-limiting examples of which are VEGF, fibroblast growth factors, nitric oxide synthases, C-type natriuretic peptide, etc.; inflammation inhibiting proteins like soluble CD40, FasL, IL-12, IL-10, IL-4, IL-13 and excreted single chain antibodies to CD4, CD5, CD7, CD52, Il-2, IL-1, IL-6, TNF, etc., or excreted single chain antibodies to the T-cell receptor on the auto-reactive T-cells. Also, dominant negative mutants of PML may be used to inhibit the immune response.
Furthermore, antagonists of inflammation promoting cytokines may be used, for example, IL-1RA (receptor antagonist) and soluble receptors like sIL-1RI, sIL-1RII, sTNFRI and sTNFRII. Growth and/or immune response inhibiting genes such as ceNOS, Bcl3, cactus and IκBα, β or γ and apoptosis inducing proteins like the VP3 protein of chicken anemia virus may also be used. Furthermore, suicide genes like HSV-TK, cytosine deaminase, nitroreductase and linamerase may be used.
A nucleic acid of interest may also be a nucleic acid that can hybridize with a nucleic acid sequence present in the host cell thereby inhibiting expression or transcription or translation of the nucleic acid. It may also block through co-suppression. In short, a “nucleic acid of interest” is any nucleic acid that one may wish to provide a cell with in order to induce a response by that cell, such as production of a protein, inhibition of such production, apoptosis, necrosis, proliferation, differentiation, etc.
The present invention is the first to disclose adenovirus 35 or a functional homologue thereof for therapeutic use, therefore, the invention also provides an Ad35 or a functional homologue thereof or a chimeric virus derived therefrom, or a gene delivery vehicle based on the virus its homologue or its chimera for use as a pharmaceutical. The serotype of the present invention, adenovirus type 35, is in itself known in the art. It is an uncommon group B adenovirus that was isolated from patients with acquired immunodeficiency syndrome and other immunodeficiency disorders (Flomenberg et al., 1987; De Jong et al., 1983). Ad 35 has been shown to differ from the more fully characterized subgroup C (including Ad2 and Ad5) with respect to pathogenic properties (Basler et al., 1996). It has been suggested that this difference may be correlated with differences in the E3 region of the Ad35 genome (Basler et al., 1996). The DNA of Ad35 has been partially cloned and mapped (Kang et al., 1989a and b; Valderrama-Leon et al., 1985).
B-type adenovirus serotypes such as 34 and 35 have a different E3 region than other serotypes. Typically, this region is involved in suppressing immune response to adenoviral products. Thus, the invention provides a gene delivery vehicle according to the invention whereby the elements involved in avoiding or diminishing immune response comprise Ad35 E3 expression products or the genes encoding them or functional equivalents of either or both.
Another part of adenoviruses involved in immune responses is the capsid, in particular the penton and/or the hexon proteins. Thus, the invention also provides a gene delivery vehicle according to the invention whereby the elements comprise at least one Ad35-capsid protein or functional part thereof, such as fiber, penton and/or hexon proteins or a gene encoding at least one of them. It is not necessary that a whole protein relevant for immune response be of Ad35 (or a functional homologue thereof) origin. It is very well possible to insert a part of an adenovirus fiber, penton or hexon protein into another fiber, penton or hexon. Thus, chimeric proteins are obtained.
It is also possible to have a penton of a certain adenovirus, a hexon from another and a fiber or an E3 region from yet another adenovirus. According to the invention, at least one of the proteins or genes encoding them should comprise an element from Ad35 or a functional homologue thereof, whereby the element has an effect on the immune response of the host. Thus, the invention provides a gene delivery vehicle according to the invention, which is a chimera of Ad35 with at least one other adenovirus. In this way one can also modify the resulting virus in other aspects than the immune response alone. One can enhance its efficiency of infection with elements responsible therefor; one can enhance its replication on a packaging cell, or one can change its tropism.
Thus, the invention, for example, provides a gene delivery vehicle according to the invention that has a different tropism than Ad35. Of course, the tropism should be altered preferably such that the gene delivery vehicle is delivered preferentially to a subset of the host's cells, i.e., the target cells. Changes in tropism and other changes that can also be applied in the present invention of adenoviral or other gene delivery vehicles are disclosed in co-pending, co-owned European Patent applications Nos. 98204482.8, 99200624.7 and 98202297.2, incorporated herein by reference. Of course, the present application also provides any and all building blocks necessary and/or useful to get to the gene delivery vehicles and/or the chimaeras, etc., of the present invention. This includes packaging cells such as PER.C6 (ECACC deposit number 96022940) or cells based thereon, but adapted for Ad35 or a functional homologue thereof; it also includes any nucleic acids encoding functional parts of Ad35 or a functional homologue thereof, such as helper constructs and packaging constructs, as well as vectors comprising genes of interest and, e.g., an ITR, etc. Typically, the previously incorporated U.S. Pat. No. 5,994,128 to Bout et al. (Nov. 30, 1999) discloses elements necessary and useful for arriving at the invented gene delivery vehicles. Thus, the invention also provides a nucleic acid encoding at least a functional part of a gene delivery vehicle according to the invention, or a virus, homologue or chimera thereof according to the invention. According to the invention, such elements, which encode functions that will end up in the resulting gene delivery vehicle must comprise or be encoded by a nucleic acid encoding at least one of the Ad35 elements or a functional equivalent thereof, responsible for avoiding or diminishing neutralizing activity against adenoviral elements by the host to which the gene is to be delivered. Typically, the gene of interest would be present on the same nucleic acid that means that such a nucleic acid has such a gene or that it has a site for introducing a gene of interest therein.
Typically, such a nucleic acid also comprises at least one ITR and, if it is a nucleic acid to be packaged, also a packaging signal. However, as mentioned before all necessary and useful elements and/or building blocks for the present invention can be found in the incorporated U.S. Pat. No. 5,994,128 to Bout et al. A set of further improvements in the field of producing adenoviral gene delivery vehicles is applicant's plasmid system disclosed in PCT/NL99/00235 mentioned herein before. This system works in one embodiment as a homologous recombination of an adapter plasmid and a longer plasmid, together comprising all elements of the nucleic acid to be incorporated in the gene delivery vehicle. These methods can also be applied to the presently invented gene delivery vehicles and their building elements. Thus, the invention also provides a nucleic acid according to the invention further comprising a region of nucleotides designed or useable for homologous recombination, preferably as part of at least one set of two nucleic acids comprising a nucleic acid according to the invention, whereby the set of nucleic acids is capable of a single homologous recombination event with each other, which leads to a nucleic acid encoding a functional gene delivery vehicle.
Both empty packaging cells (in which the vector to be packaged to make a gene delivery vehicle according to the invention still has to be introduced or produced) as well as cells comprising a vector according to the invention to be packaged are provided. Thus, the invention also encompasses a cell comprising a nucleic acid according to the invention or a set of nucleic acids according to the invention, preferably a cell which complements the necessary elements for adenoviral replication which are absent from the nucleic acid to be packaged, or from a set of nucleic acids according to the invention. In the present invention, it has been found that E1-deleted Ad35 vectors, are not capable of replication on cells that provide adenovirus 5 proteins in trans. The invention therefore further provides a cell capable of providing Ad35 E1 proteins in trans. Such a cell is typically a human cell derived from the retina or the kidney. Embryonic cells, such as amniocytes, have been shown to be particularly suited for the generation of an E1-complementing cell line. Such cells are, therefore, preferred in the present invention. Serotype specific complementation by E1 proteins can be due to one or more protein(s) encoded by the E1 region. It is, therefore, essential that at least the serotype specific protein be provided in trans in the complementing cell line. The non-serotype specific E1 proteins essential for effective complementation of an E1-deleted adenovirus can be derived from other adenovirus serotypes. Preferably, at least an E1 protein from the E1B region of Ad35 is provided in trans to complement E1-deleted Ad35 based vectors. In one embodiment, nucleic acid encoding the one or more serotype specific E1-proteins is introduced into the PER.C6 cell or a cell originating from a PER.C6 cell, or a similar packaging cell complementing with elements from Ad 35 or a functional homologue thereof.
As already alluded to, the invention also encompasses a method for producing a gene delivery vehicle according to the invention, comprising expressing a nucleic acid according to the invention in a cell according to the invention and harvesting the resulting gene delivery vehicle. The above refers to the filling of the empty packaging cell with the relevant nucleic acids. The format of the filled cell is, of course, also part of the present invention, which provides a method for producing a gene delivery vehicle according to the invention, comprising culturing a filled packaging cell (producer cell) according to the invention in a suitable culture medium and harvesting the resulting gene delivery vehicle.
The resulting gene delivery vehicles obtainable by any method according to the invention are, of course, also part of the present invention, particularly also a gene delivery vehicle which is derived from a chimera of an adenovirus and an integrating virus.
It is well known that adenoviral gene delivery vehicles do not normally integrate into the host genome. For long-term expression of genes in a host cell, it is therefore preferred to prepare chimaeras that do have that capability. Such chimaeras have been disclosed in co-pending, co-owned International Patent Application PCT/NL98/00731 incorporated herein by reference. A very good example of a chimera of an adenovirus and an integrating virus is where the integrating virus is an adeno-associated virus. As discussed hereinbefore, other useful chimaeras, which can also be combined with the above, are chimaeras (be it in swapping whole proteins or parts thereof or both) that have altered tropism. A very good example thereof is a chimera of Ad 35 and Ad 16, possibly with elements from, for instance, Ad 2 or Ad 5, wherein the tropism determining part of Ad 16 or a functional equivalent thereof is used to direct the gene delivery vehicle to synoviocytes and/or smooth muscle cells (see co-pending, co-owned European patent applications nos. 98204482.8 and 99200624.7) incorporated herein by reference). Dendritic cells (“DC”) and hemopoietic stem cells (“HSC”) are not easily transduced with Ad2 or Ad5 derived gene delivery vehicles. The present invention provides gene delivery vehicles that possess increased transduction capacity of DC and HSC cells. Such gene delivery vehicles at least comprise the tissue tropism determining part of an Ad35 adenovirus. The invention therefore further provides the use of a tissue tropism determining part of an Ad35 capsid for transducing dendritic cells and/or hemopoietic stem cells. Other B-type adenoviruses are also suited. A tissue tropism determining part comprises at least the knob and/or the shaft of a fiber protein. Of course, it is very well possible for a person skilled in the art to determine the amino acid sequences responsible for the tissue tropism in the fiber protein. Such knowledge can be used to devise chimeric proteins comprising such amino acid sequences. Such chimeric proteins are therefore also part of the invention.
DCs are very efficient antigen presenting cells. By introducing the gene delivery vehicle into such cells, the host's immune system can be triggered toward specific antigens. Such antigens can be encoded by nucleic acid delivered to the DC or by the proteins of the gene delivery vehicle itself. The present invention therefore also provides a gene delivery vehicle with the capacity to evade the host immune system as a vaccine. The vector being capable of evading the immune system long enough to efficiently find target cells and at the same time capable of delivering specific antigens to antigen presenting cells thereby allowing the induction and/or stimulation of efficient immune responses toward the specific antigen(s). To further modulate the immune response, the gene delivery vehicle may comprise proteins and/or nucleic acids encoding such proteins capable of modulating an immune response. Non-limiting examples of such proteins are found among the interleukins, adhesion molecules, co-stimulatory proteins, the interferons, etc. The invention therefore further provides a vaccine comprising a gene delivery vehicle of the invention. The invention further provides an adenovirus vector with the capacity to efficiently transduce DC and/or HSC, the vehicle comprising at least a tissue tropism determining part of Ad35. The invention further provides the use of such delivery vehicles for the transduction of HSC and/or DC cells. Similar tissue tropisms are found among other adenoviruses of serotype B, particularly in Ad11 and are also part of the invention. Of course, it is also possible to provide other gene delivery vehicles with the tissue tropism determining part thereby providing such delivery vehicles with an enhanced DC and/or HSC transduction capacity. Such gene delivery vehicles are therefore also part of the invention.
The gene delivery vehicles according to the invention can be used to deliver genes or nucleic acids of interest to host cells. Such use will typically be a pharmaceutical one. Such a use is included in the present invention. Compositions suitable for such a use are also part of the present invention. The amount of gene delivery vehicle that needs to be present per dose or per infection (“m.o.i”) will depend on the condition to be treated, the route of administration (typically parenteral) the subject and the efficiency of infection, etc. Dose finding studies are well known in the art and those already performed with other (adenoviral) gene delivery vehicles can typically be used as guides to find suitable doses of the gene delivery vehicles according to the invention. Typically, this is also where one can find suitable excipients, suitable means of administration, suitable means of preventing infection with the vehicle where it is not desired, etc. Thus, the invention also provides a pharmaceutical formulation comprising a gene delivery vehicle according to the invention and a suitable excipient, as well as a pharmaceutical formulation comprising an adenovirus, a chimera thereof, or a functional homologue thereof according to the invention and a suitable excipient.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 : Bar graph showing the percentage of serum samples positive for neutralization for each human wt adenovirus tested (see, Example 1 for description of the neutralization assay).
FIG. 2 : Graph showing absence of correlation between the VP/CCID50 ratio and the percentage of neutralization.
FIG. 3 : Schematic representation of a partial restriction map of Ad35 (taken from Kang et al., 1989) and the clones generated to make recombinant Ad35-based viruses.
FIG. 4 : Bar graph presenting the percentage sera samples that show neutralizing activity to a selection of adenovirus serotypes. Sera were derived from healthy volunteers from Belgium and the UK.
FIG. 5 : Bar graph presenting the percentage sera samples that show neutralizing activity to adenovirus serotypes 5, 11, 26, 34, 35, 48 and 49. Sera were derived from five different locations in Europe and the United States.
FIG. 6 : Sequence of human adenovirus type 35 (SEQ ID NO:82).
FIG. 7 : Map of pAdApt.
FIG. 8 : Map of pIPspAdapt.
FIG. 9 : Map of pIPspAdapt1.
FIG. 10 : Map of pIPspAdapt3.
FIG. 11 : Map of pAdApt35IP3.
FIG. 12 : Map of pAdApt35IP1.
FIG. 13 : Schematic representation of the steps undertaken to construct pWE.Ad35.pIX-rITR.
FIG. 14 : Map of pWE.Ad35.pIX-rITR.
FIG. 15 : Map of pRSV.Ad35-E1.
FIG. 16 : Map of PGKneopA
FIG. 17 : Map of pRSVpNeo.
FIG. 18 : Map of pRSVhbvNeo.
FIG. 19 : Flow cytometric analyses on GFP expression in human TF-1 cells. Non-transduced TF-1 cells were used to set a background level of 1%. GFP expression in cells transduced with Ad5, Ad5.Fib16, Ad5.Fib17, Ad5.Fib40-L, Ad5.Fib35, and Ad5.Fib51 is shown.
FIG. 20 : Transduction of primary human fibroblast-like stroma. Cells were analyzed 48 hours after a two-hour exposure to the different chimeric fiber viruses. Shown is percentage of cells found positive for the transgene: GFP using a flow cytometer. Non-transduced stroma cells were used to set a background at 1%. Results of different experiments (n=3) are shown ±standard deviation.
FIG. 21 : Transduction of primary human fibroblast-like stroma, CD34 + cells and CD34 + Lin − cells. Cells were analyzed five days after a two-hour exposure to the different chimeric fiber viruses. Shown is percentage of cells found positive for the transgene: GFP using a flow cytometer. Non-transduced cells were used to set a background at 1%. Also shown is the number of GFP positive events divided by the total number of events analyzed (between brackets).
FIG. 22 : A) Flow cytometric analysis of GFP positive cells after transduction of CD34 + cells with Ad5.Fib51. All cells gated in R2-R7 are positive for CD34 but differ in their expression of early differentiation markers CD33, CD38, and CD71 (Lin). Cells in R2 are negative for CD333, CD38, and CD71 whereas cells in R7 are positive for these markers. To demonstrate specificity of Ad5.Fib51 the percentage of GFP positive cells was determined in R2-R7 that proofed to decline from 91% (R2) to 15% (R7). B) Identical experiment as shown under A (X-axes is R2-R7) but for the other Ad fiber chimeric viruses showing that Ad5.Fib35, and Ad5.Fib 16 behave similar as Ad5.Fib51.
FIG. 23 : Alignment of the chimeric fiber proteins of Ad5fib16 (SEQ ID NO:83), Ad5fib35 (SEQ ID NO:84) and Ad5fib51 (SEQ ID NO:85) with the Ad5 fiber sequence (SEQ ID NO:86).
FIG. 24 : Toxicity of Adenovirus exposure to primitive human bone marrow cells and stem cells. Cell cultures were counted just before and five days after adenovirus transduction. Shown is the percentage of primitive human bone marrow cells (CD34 + ) and HSCs (CD34 + Lin − ) recovered as compared to day 0.
FIG. 25 : Transduction of immature DCs at a virus dose of 100 or 1000 virus particles per cell. Virus tested is Ad5 and Ad5 based vectors carrying the fiber of serotype 12 (Ad5.Fib12), 16 (Ad5.Fib16), 28 (Ad5.Fib28), 32 (Ad5.Fib32), the long fiber of 40 (Ad5.Fib40-L, 49 (Ad5.Fib49), 51 (Ad5.Fib51). Luciferase transgene expression is expressed as relative light units per microgram of protein.
FIG. 26 : Flow cytometric analyses of LacZ expression on immature and mature DCs transduced with 10000 virus particles per cell of Ad5 or the fiber chimeric vectors Ad5.Fib16, Ad5.Fib40-L, or Ad5.Fib51. Percentages of cells scored positive are shown in upper left corner of each histogram.
FIG. 27 : Luciferase transgene expression in human immature DCs measured 48 hours after transduction with 1000 or 5000 virus particles per cell. Viruses tested were fiber chimeric viruses carrying the fiber of subgroup B members (serotypes 11, 16, 35, and 51).
FIG. 28 : GFP expression in immature human DCs 48 hours after transduction with 1000 virus particles per cell of Ad5, Ad5.Fib16, and Ad5.Fib35. Non-transduced cells were used to set a background level of approximately 1% (−).
FIG. 29 : Transduction of mouse and chimpanzee DCs. Luciferase transgene expression measured in mouse DCs 48 hours after transduction is expressed as relative light units per microgram of protein. Chimpanzee DCs were measured 48 hours after transduction using a flow cytometer. GFP expression demonstrates the poor transduction of Ad (35) in contrast to Ad5.Fib35 (66%).
FIG. 30 : Temperature dependent growth of PER.C6. PER.C6 cells were cultured in DMEM supplemented with 10% FBS (Gibco BRL) and 10 mM MgCl 2 in a 10% CO 2 atmosphere at 32° C., 37° C. or 39° C. At day 0, a total of 1×10 6 PER.C6 cells were seeded per 25 cm 2 tissue culture flask (Nunc) and the cells were cultured at 32° C., 37° C. or 39° C. At days 1-8, cells were counted. The growth rate and the final cell density of the PER.C6 culture at 39° C. are comparable to that at 37° C. The growth rate and final density of the PER.C6 culture at 32° C. were slightly reduced as compared to that at 37° C. or 39° C. PER.C6 cells were seeded at a density of 1×10 6 cells per 25 cm 2 tissue culture flask and cultured at 32°, 37° or 39° C. At the indicated time points, cells were counted in a Burker cell counter. PER.C6 grows well at 32°, 37° and 39° C.
FIG. 31 : DBP levels in PER.C6 cells transfected with pcDNA3, pcDNA3 wtE2A or pcDNA3ts125E2A. Equal amounts of whole-cell extract were fractionated by SDS-PAGE on 10% gels. Proteins were transferred onto Immobilon-P membranes and DBP protein was visualized using the αDBP monoclonal B6 in an ECL detection system. All of the cell lines derived from the pcDNA3ts125E2A transfection express the 72-kDa E2A-encoded DBP protein (left panel: lanes 4-14; middle panel: lanes 1-13; right panel: lanes 1-12). In contrast, the only cell line derived from the pcDNAwtE2A transfection did not express the DBP protein (left panel, lane 2). No DBP protein was detected in extract from a cell line derived from the pcDNA3 transfection (left panel, lane 1), which serves as a negative control. Extract from PER.C6 cells transiently transfected with pcDNA3ts125 (left panel, lane 3) served as a positive control for the Western blot procedure. These data confirm that constitutive expression of wtE2A is toxic for cells and that using the ts125 mutant of E2A can circumvent this toxicity.
FIG. 32 : Suspension growth of PER.C6ts125E2A C5-9. The tsE2A expressing cell line PER.C6tsE2A.c5-9 was cultured in suspension in serum-free Ex-cellä. At the indicated time points, cells were counted in a Burker cell counter. The results of eight independent cultures are indicated. PER.C6tsE2A grows well in suspension in serum free Ex-cellä medium.
FIG. 33 : Growth curve PER.C6 and PER.C6tsE2A. PER.C6 cells or PER.C6ts125E2A (c8-4) cells were cultured at 37° C. or 39° C., respectively. At day 0, a total of 1×10 6 cells were seeded per 25 cm 2 tissue culture flask. At the indicated time points, cells were counted. The growth of PER.C6 cells at 37° C. is comparable to the growth of PER.C6ts125E2A c8-4 at 39° C. This shows that constitutive over-expression of ts125E2A has no adverse effect on the growth of cells at the non-permissive temperature of 39° C.
FIG. 34 : Stability of PER.C6ts125E2A. For several passages, the PER.C6ts125E2A cell line clone 8-4 was cultured at 39° C. in medium without G418. Equal amounts of whole-cell extract from different passage numbers were fractionated by SDS-PAGE on 10% gels. Proteins were transferred onto Immobilon-P membranes and DBP protein was visualized using the αDBP monoclonal B6 in an ECL detection system. The expression of ts125E2A encoded DBP is stable for at least 16 passages, which is equivalent to approximately 40 cell doublings. No decrease in DBP levels was observed during this culture period, indicating that the expression of ts125E2A is stable, even in the absence of G418 selection pressure.
FIG. 35 : tTA activity in hygromycin resistant PER.C6/tTA (A) and PER/E2A/tTA (B) cells. Sixteen independent hygromycin resistant PER.C6/tTA cell colonies and 23 independent hygromycin resistant PER/E2A/tTA cell colonies were grown in 10 cm 2 wells to sub-confluency and transfected with 2 μg of pUHC 13-3 (a plasmid that contains the reporter gene luciferase under the control of the 7xtetO promoter). One-half of the cultures were maintained in medium containing doxycycline to inhibit the activity of tTA. Cells were harvested at 48 hours after transfection and luciferase activity was measured. The luciferase activity is indicated in relative light units (RLU) per μg protein.
DETAILED DESCRIPTION OF THE INVENTION
As previously stated, the most extensively studied serotypes of adenovirus are not ideally suited for delivering additional genetic material to host cells. This fact is partially due to the pre-existing immunity among the population against these serotypes. This presence of pre-existing antibodies in humans, in combination with a strong secondary humoral and cellular immune response against the virus will affect adenoviral gene therapy.
The present invention provides the use of at least elements of a serotype and functional homologues thereof of adenovirus that are very suitable as gene therapy vectors. The present invention also discloses an automated high-throughput screening of all known adenovirus serotypes against sera from many individuals. Surprisingly, no neutralizing ability was found in any of the sera that were evaluated against one particular serotype, adenovirus 35 (“Ad35”). This makes the serotype of the present invention extremely useful as a vector system for gene therapy in man. Such a vector system is capable of efficiently transferring genetic material to a human cell without the inherent problem of pre-existing immunity.
Typically, a virus is produced using an adenoviral vector (typically a plasmid, cosmid, or baculovirus vector). Such vectors are, of course, also part of the present invention.
The invention also provides adenovirus-derived vectors that have been rendered replication defective by deletion or inactivation of the E1 region. Of course, a gene of interest can also be inserted at, for instance, the site of E1 of the original adenovirus from which the vector is derived.
In all aspects of the invention, the adenoviruses may contain deletions in the E1 region and insertions of heterologous genes either linked or not to a promoter. Furthermore, the adenoviruses may contain deletions in the E2, E3 or E4 regions and insertions of heterologous genes linked to a promoter. In these cases, E2- and/or E4-complementing cell lines are used to generate recombinant adenoviruses.
One may choose to use the Ad35 serotype itself for the preparation of recombinant adenoviruses to be used in gene therapy. Alternatively, one may choose to use elements derived from the serotype of the present invention in such recombinant adenoviruses. One may, for instance, develop a chimeric adenovirus that combines desirable properties from different serotypes. Some serotypes have a somewhat limited host range, but have the benefit of being less immunogenic; while others are the other way around. Some have a problem of being of a limited virulence, but have a broad host range and/or a reduced immunogenicity. Such chimeric adenoviruses are known in the art, and they are intended to be within the scope of the present invention. Thus, in one embodiment, the invention provides a chimeric adenovirus comprising at least a part of the adenovirus genome of the present serotype, providing it with absence of pre-existing immunity, and at least a part of the adenovirus genome from another adenovirus serotype resulting in a chimeric adenovirus. In this manner, the chimeric adenovirus produced is such that it combines the absence of pre-existing immunity of the serotype of the present invention, to other characteristics of another serotype. Such characteristics may be temperature stability, assembly, anchoring, redirected infection, production yield, redirected or improved infection, stability of the DNA in the target cell, etc.
A packaging cell will generally be needed in order to produce sufficient amount of adenoviruses. For the production of recombinant adenoviruses for gene therapy purposes, several cell lines are available. These include but are not limited to the known cell lines PER.C6, 911, 293, and E1 A549.
An important feature of the present invention is the means to produce the adenovirus. Typically, one does not want an adenovirus batch for clinical applications to contain replication competent adenovirus. In general, therefore, it is desired to omit a number of genes (but at least one) from the adenoviral genome on the adenoviral vector and to supply these genes in the genome of the cell in which the vector is brought to produce chimeric adenovirus. Such a cell is usually called a “packaging cell.” The invention thus also provides a packaging cell for producing an adenovirus (a gene delivery vehicle) according to the invention, comprising in trans all elements necessary for adenovirus production not present on the adenoviral vector according to the invention. Typically, vectors and packaging cells have to be adapted to one another so that they have all the necessary elements, but do not have overlapping elements which lead to replication competent virus by recombination.
Thus, the invention also provides a kit of parts comprising a packaging cell according to the invention and a recombinant vector according to the invention wherein essentially no sequence overlap leading to recombination resulting in the production of replication competent adenovirus exists between the cell and the vector.
Thus, the invention provides methods for producing adenovirus, which, upon application, will escape pre-existing humoral immunity. Such methods include providing a vector with elements derived from an adenovirus serotype against which virtually no natural immunity exists and transfecting the vector in a packaging cell according to the invention and allowing for production of viral particles.
In one aspect, the invention includes the use of the adenovirus serotype of the present invention to overcome naturally existing or induced, neutralizing host activity towards adenoviruses administered in vivo for therapeutic applications. The need for a new serotype is stressed by observations that 1) repeated systemic delivery of recombinant Ad5 is unsuccessful due to the formation of high titers of neutralizing antibodies against recombinant Ad5 (Schulick et al., 1997), and 2) pre-existing or humoral immunity is already widespread in the population.
In another aspect, the invention provides the use of gene delivery vehicles of the invention or the use of Ad35 for vaccination purposes. Such use prevents, at least in part, undesired immune responses of the host. Non-limiting examples of undesired immune responses include evoking an immune response against the gene delivery vehicle or Ad35 and/or boosting an immune response against the gene delivery vehicle or Ad35.
In another aspect of the invention, alternating use is made of Ad vectors belonging to different subgroups. This aspect of the invention therefore circumvents the inability to repeat the administration of an adenovirus for gene therapy purposes.
The invention is further explained by the use of the following illustrative Examples.
EXAMPLES
Example 1
A High Throughput Assay for the Detection of Neutralizing Activity in Human Serum
To enable screening of a large amount of human sera for the presence of neutralizing antibodies against all adenovirus serotypes, an automated 96-well assay was developed.
Human Sera
A panel of 100 individuals was selected. Volunteers (50% male, 50% female) were healthy individuals between ages 20 and 60 years old with no restriction for race. All volunteers signed an informed consent form. People professionally involved in adenovirus research were excluded.
Approximately 60 ml blood was drawn in dry tubes. Within two hours after sampling, the blood was centrifuged at 2500 rpm for 10 minutes. Approximately 30 ml serum was transferred to polypropylene tubes and stored frozen at −20° C. until further use.
Serum was thawed and heat-inactivated at 56° C. for 10 minutes and then aliquoted to prevent repeated cycles of freeze/thawing. Part was used to make five steps of twofold dilutions in medium (DMEM, Gibco BRL) in a quantity enough to fill out approximately 70 96-well plates. Aliquots of undiluted and diluted sera were pipetted in deep well plates (96-well format) and, using a programmed platemate, dispensed in 100 μl aliquots into 96-well plates. This way the plates were loaded with eight different sera in duplo (100 μl/well) according to the scheme below:
S1/2 S1/4 S1/8 S1/16 S1/32 S5/2 S5/4 S5/8 S5/16 S5/32 — — S1/2 S1/4 S1/8 S1/16 S1/32 S5/2 S5/4 S5/8 S5/16 S5/32 — — S2/2 S2/4 S2/8 S2/16 S2/32 S6/2 S6/4 S6/8 S6/16 S6/32 — — S2/2 S2/4 S2/8 S2/16 S2/32 S6/2 S6/4 S6/8 S6/16 S6/32 — — S3/2 S3/4 S3/8 S3/16 S3/32 S7/2 S7/4 S7/8 S7/16 S7/32 — — S3/2 S3/4 S3/8 S3/16 S3/32 S7/2 S7/4 S7/8 S7/16 S7/32 — — S4/2 S4/4 S3/8 S3/16 S3/32 S8/2 S8/4 S8/8 S8/16 S8/32 — — S4/2 S4/4 S3/8 S3/16 S3/32 S8/2 S8/4 S8/8 S8/16 S8/32 — —
Where S1/2 to S8/2 in columns 1 and 6 represent 1× diluted sera and Sx/4, Sx/8, Sx/16 and Sx/32 the twofold serial dilutions. The last plates also contained four wells filled with 100 μl fetal calf serum as a negative control.
Plates were kept at −20° C. until further use.
Preparation of Human Adenovirus Stocks
Prototypes of all known human adenoviruses were inoculated on T25 flasks seeded with PER.C6 cells (Fallaux et al., 1998) and harvested upon full CPE. After freeze/thawing 1-2 ml of the crude lysates was used to inoculate a T80 flask with PER.C6 and virus was harvested at full CPE. The timeframe between inoculation and occurrence of CPE as well as the amount of virus needed to re-infect a new culture, differed between serotypes. Adenovirus stocks were prepared by freeze/thawing and used to inoculate 3-4 T175 cm 2 three-layer flasks with PER.C6 cells. Upon occurrence of CPE, cells were harvested by tapping the flask, pelleted and virus was isolated and purified by a two-step CsCl gradient as follows. Cell pellets were dissolved in 50 ml 10 mM NaPO 4 buffer (pH 7.2) and frozen at −20° C. After thawing at 37° C., 5.6 ml sodium deoxycholate (5% w/v) was added. The solution was mixed gently and incubated for 5-15 minutes at 37° C. to completely lyse the cells. After homogenizing the solution, 1875 μl 1M MgCl 2 was added. After the addition of 375 μl DNAse (10 mg/ml) the solution was incubated for 30 minutes at 37° C. Cell debris was removed by centrifugation at 1880×g for 30 minutes at RT without brake. The supernatant was subsequently purified from proteins by extraction with FREON (3×). The cleared supernatant was loaded on a 1M Tris/HCl buffered cesium chloride block gradient (range: 1.2/1.4 g/ml) and centrifuged at 21000 rpm for 2.5 hours at 10° C. The virus band was isolated after which a second purification using a 1M Tris/HCl buffered continuous gradient of 1.33 g/ml of cesium chloride was performed. The virus was then centrifuged for 17 hours at 55000 rpm at 10° C. The virus band was isolated and sucrose (50% w/v) was added to a final concentration of 1%. Excess cesium chloride was removed by dialysis (three times 1 hour at RT) in dialysis slides (Slide-a-lizer, cut off 10000 kDa, Pierce, USA) against 1.5 liter PBS supplemented with CaCl 2 (0.9 mM), MgCl 2 (0.5 mM) and an increasing concentration of sucrose (1, 2, 5%). After dialysis, the virus was removed from the slide-a-lizer after which it was aliquoted in portions of 25 and 100 μl upon which the virus was stored at −85° C.
To determine the number of virus particles per milliliter, 50 μl of the virus batch was run on a high-pressure liquid chromatograph (HPLC) as described by Shabram et al. (1997). Viruses were eluted using a NaCl gradient ranging from 0 to 600 mM. As depicted in table I, the NaCl concentration by which the viruses were eluted differed significantly among serotypes.
Most human adenoviruses replicated well on PER.C6 cells with a few exceptions. Adenovirus type 8 and 40 were grown on 911-E4 cells (He et al., 1998). Purified stocks contained between 5×10 10 and 5×10 12 virus particles/ml (VP/ml; see table I).
Titration of Purified Human Adenovirus Stocks
Adenoviruses were titrated on PER.C6 cells to determine the amount of virus necessary to obtain full CPE in five days, the length of the neutralization assay. Hereto, 100 μl medium was dispensed into each well of 96-well plates. 25 μl of adenovirus stocks pre-diluted 10 4 , 10 5 , 10 6 or 10 7 times were added to column 2 of a 96-well plate and mixed by pipetting up and down ten times. Then 25 μl was brought from column 2 to column 3 and again mixed. This was repeated until column 11 after which 25 μl from column 11 was discarded. This way, serial dilutions in steps of five were obtained starting off from a pre-diluted stock. Then 3×10 4 PER.C6 cells (ECACC deposit number 96022940) were added in a 100 μl volume and the plates were incubated at 37° C., 5% CO 2 for five or six days. CPE was monitored microscopically. The method of Reed and Muensch was used to calculate the cell culture-inhibiting dose 50% (CCID50).
In parallel, identical plates were set up that were analyzed using the MTT assay (Promega). In this assay living cells are quantified by colorimetric staining. Hereto, 20 μl MTT (7.5 mgr/ml in PBS) was added to the wells and incubated at 37° C., 5% CO 2 for two hours. The supernatant was removed and 100 μl of a 20:1 isopropanol/triton-X100 solution was added to the wells. The plates were put on a 96-wells shaker for three to five minutes to solubilize the precipitated staining. Absorbance was measured at 540 nm and at 690 nm (background). By this assay, wells with proceeding CPE or full CPE can be distinguished.
Neutralization Assay
96-well plates with diluted human serum samples were thawed at 37° C., 5% CO 2 . Adenovirus stocks diluted to 200 CCID50 per 50 μl were prepared and 50 μl aliquots were added to columns 1-11 of the plates with serum. Plates were incubated for one hour at 37° C., 5% CO 2 . Then 50 μl PER.C6 cells at 6×10 5 /ml were dispensed in all wells and incubated for one day at 37° C., 5% CO 2 . Supernatant was removed using fresh pipette tips for each row and 200 μl fresh medium was added to all wells to avoid toxic effects of the serum. Plates were incubated for another four days at 37° C., 5% CO 2 . In addition, parallel control plates were set up in duplo with diluted positive control sera generated in rabbits and specific for each serotype to be tested in rows A and B and with negative control serum (FCS) in rows C and D. Also, in each of the rows E-H a titration was performed as described above with steps of five times dilutions starting with 200 CCID50 of each virus to be tested. On day 5, one of the control plates was analyzed microscopically and with the MTT assay. The experimental titer was calculated from the control titration plate observed microscopically. If CPE was found to be complete, i.e., the first dilution in the control titration experiment analyzed by MTT shows clear cell death, all assay plates were processed. If not, the assay was allowed to proceed for one or more days until full CPE was apparent after which all plates were processed. In most cases, the assay was terminated at day 5. For Ad1, 5, 33, 39, 42 and 43 the assay was left for six days and for Ad2 for eight days.
A serum sample is regarded as “non-neutralizing” when, at the highest serum concentration, a maximum protection of 40% is seen compared to controls without serum.
The results of the analysis of 44 prototype adenoviruses against serum from 100 healthy volunteers are shown in FIG. 1 . As expected, the percentage of serum samples that contained neutralizing antibodies to Ad2 and Ad5 was very high. This was also true for most of the lower numbered adenoviruses. Surprisingly, none of the serum samples contained neutralizing antibodies to Ad35. Also, the number of individuals with neutralizing antibody titers to the serotypes 26, 34 and 48 was very low. Therefore, recombinant E1-deleted adenoviruses based on Ad35 or one of the other above mentioned serotypes have an important advantage compared to recombinant vectors based on Ad5 with respect to clearance of the viruses by neutralizing antibodies.
Also, Ad5-based vectors that have (parts of) the capsid proteins involved in immunogenic response of the host replaced by the corresponding (parts of) the capsid proteins of Ad35 or one of the other serotypes will be less, or even not, neutralized by the vast majority of human sera.
As can be seen in Table I, the VP/CCID50 ratio calculated from the virus particles per ml and the CCID50 obtained for each virus in the experiments was highly variable, and ranged from 0.4 to 5 log. This is probably caused by different infection efficiencies of PER.C6 cells and by differences in replication efficiency of the viruses. Furthermore, differences in batch qualities may play a role. A high VP/CCID50 ratio means that more viruses were put in the wells to obtain CPE in five days. As a consequence, the outcome of the neutralization study might be biased since more (inactive) virus particles could shield the antibodies. To check whether this phenomenon had taken place, the VP/CCID50 ratio was plotted against the percentage of serum samples found positive in the assay ( FIG. 2 ). The graph clearly shows that there is no negative correlation between the amount of viruses in the assay and neutralization in serum.
Example 2
Generation of Ad5 Plasmid Vectors for the Production of Recombinant Viruses and Easy Manipulation of Adenoviral Genes
pBr/Ad.Bam-rITR (ECACC Deposit P97082122)
In order to facilitate blunt end cloning of the ITR sequences, wild-type human adenovirus type 5 (Ad5) DNA was treated with Klenow enzyme in the presence of excess dNTPs. After inactivation of the Klenow enzyme and purification by phenol/chloroform extraction followed by ethanol precipitation, the DNA was digested with BamHI. This DNA preparation was used without further purification in a ligation reaction with pBr322 derived vector DNA prepared as follows: pBr322 DNA was digested with EcoRV and BamHI, dephosphorylated by treatment with TSAP enzyme (Life Technologies) and purified on LMP agarose gel (SeaPlaque GTG). After transformation into competent E. coli DH5α (Life Techn.) and analysis of ampicillin resistant colonies, one clone was selected that showed a digestion pattern as expected for an insert extending from the BamHI site in Ad5 to the right ITR.
Sequence analysis of the cloning border at the right ITR revealed that the most 3′ G residue of the ITR was missing, the remainder of the ITR was found to be correct. The missing G residue is complemented by the other ITR during replication.
pBr/Ad.Sal-rITR (ECACC Deposit P97082119)
pBr/Ad.Bam-rITR was digested with BamHI and SalI. The vector fragment including the adenovirus insert was isolated in LMP agarose (SeaPlaque GTG) and ligated to a 4.8 kb SalI-BamHI fragment obtained from wt Ad5 DNA and purified with the GENECLEAN II kit (Bio 101, Inc.). One clone was chosen and the integrity of the Ad5 sequences was determined by restriction enzyme analysis. Clone pBr/Ad.Sal-rITR contains Ad5 sequences from the SalI site at bp 16746 up to and including the rITR (missing the most 3′ G residue).
pBr/Ad. Cla-Bam (ECACC Deposit P97082117)
Wild-type (“wt”) Ad5 DNA was digested with ClaI and BamHI, and the 20.6 kb fragment was isolated from gel by electro-elution. pBr322 was digested with the same enzymes and purified from agarose gel by GENECLEAN. Both fragments were ligated and transformed into competent DH5α. The resulting clone pBr/Ad.Cla-Bam was analyzed by restriction enzyme digestion and shown to contain an insert with adenovirus sequences from bp 919 to 21566.
pBr/Ad.AflII-Bam (ECACC Deposit P97082114)
Clone pBr/Ad.Cla-Bam was linearized with EcoRI (in pBr322) and partially digested with AflII. After heat inactivation of AflII for 20 minutes at 65° C., the fragment ends were filled in with Klenow enzyme. The DNA was then ligated to a blunt double-stranded oligo linker containing a PacI site (5′-AATTGTCTTAATTAACCGCTTAA-3′ (SEQ ID NO:1)). This linker was made by annealing the following two oligonucleotides: 5′-AATTGTCTTAATTAACCGC-3′ (SEQ ID NO:2) and 5′-AATTGCGGTTAATTAAGAC-3′ (SEQ ID NO:3), followed by blunting with Klenow enzyme. After precipitation of the ligated DNA to change buffer, the ligations were digested with an excess PacI enzyme to remove concatameres of the oligo. The 22016 bp partial fragment containing Ad5 sequences from bp 3534 up to 21566 and the vector sequences, was isolated in LMP agarose (SeaPlaque GTG), re-ligated and transformed into competent DH5a. One clone that was found to contain the PacI site and that had retained the large adeno fragment was selected and sequenced at the 5′ end to verify correct insertion of the PacI linker in the (lost) Afll site.
pBr/Ad.Bam-rlTRpac#2 (ECACC Deposit P97082120) and pBr/Ad.Bam-rITRpac#8 (ECACC Deposit P97082121)
To allow insertion of a PacI site near the ITR of Ad5 in clone pBr/Ad.Bam-rITR, about 190 nucleotides were removed between the ClaI site in the pBr322 backbone and the start of the ITR sequences. This was done as follows: pBr/Ad.Bam-rITR was digested with ClaI and treated with nuclease Bal31 for varying lengths of time (2 minutes, 5 minutes, 10 minutes and 15 minutes). The extent of nucleotide removal was followed by separate reactions on pBr322 DNA (also digested at the ClaI site), using identical buffers and conditions. Bal31 enzyme was inactivated by incubation at 75° C. for 10 minutes, the DNA was precipitated and re-suspended in a smaller volume TE buffer. To ensure blunt ends, DNAs were further treated with T4 DNA polymerase in the presence of excess dNTPs. After digestion of the (control) pBr322 DNA with SalI, satisfactory degradation (˜150 bp) was observed in the samples treated for 10 minutes or 15 minutes. The 10 minutes or 15 minutes treated pBr/Ad.Bam-rITR samples were then ligated to the above described blunted PacI linkers (See pBr/Ad.AflII-Bam). Ligations were purified by precipitation, digested with excess PacI and separated from the linkers on an LMP agarose gel. After re-ligation, DNAs were transformed into competent DH5α and colonies analyzed. Ten clones were selected that showed a deletion of approximately the desired length and these were further analyzed by T-track sequencing (T7 sequencing kit, Pharmacia Biotech). Two clones were found with the PacI linker inserted just downstream of the rITR. After digestion with PacI, clone #2 has 28 bp and clone #8 has 27 bp attached to the ITR.
pWE/Ad.AflII-rITR (ECACC Deposit P97082116)
Cosmid vector pWE15 (Clontech) was used to clone larger Ad5 inserts. First, a linker containing a unique PacI site was inserted in the EcoRI sites of pWE15 creating pWE.pac. To this end, the double stranded PacI oligo as described for pBr/Ad.AflII-BamHI was used but now with its EcoRI protruding ends. The following fragments were then isolated by electro-elution from agarose gel: pWE.pac digested with PacI, pBr/AflII-Bam digested with PacI and BamHI and pBr/Ad.Bam-rITR#2 digested with BamHI and PacI. These fragments were ligated together and packaged using λ phage packaging extracts (Stratagene) according to the manufacturer's protocol. After infection into host bacteria, colonies were grown on plates and analyzed for presence of the complete insert. pWE/Ad.AflII-rITR contains all adenovirus type 5 sequences from bp 3534 (AflII site) up to and including the right ITR (missing the most 3′ G residue).
pBr/Ad.lITR-Sal(9.4) (ECACC Deposit P97082115)
Adeno 5 wt DNA was treated with Klenow enzyme in the presence of excess dNTPs and subsequently digested with SalI. Two of the resulting fragments, designated left ITR-Sal(9.4) and Sal(16.7)-right ITR, respectively, were isolated in LMP agarose (Seaplaque GTG). pBr322 DNA was digested with EcoRV and SalI and treated with phosphatase (Life Technologies). The vector fragment was isolated using the GENECLEAN method (BIO 101, Inc.) and ligated to the Ad5 SalI fragments. Only the ligation with the 9.4 kb fragment gave colonies with an insert. After analysis and sequencing of the cloning border a clone was chosen that contained the full ITR sequence and extended to the SalI site at bp 9462.
pBr/Ad.lITR-Sal(16.7) (ECACC Deposit P97082118)
pBr/Ad.lITR-Sal(9.4) is digested with SalI and dephosphorylated (TSAP, Life Technologies). To extend this clone up to the third SalI site in Ad5, pBr/Ad.Cla-Bam was linearized with BamHI and partially digested with SalI. A 7.3 kb SalI fragment containing adenovirus sequences from 9462-16746 was isolated in LMP agarose gel and ligated to the SalI-digested pBr/Ad.lITR-Sal(9.4) vector fragment.
pWE/Ad.AflII-EcoRI
pWE.pac was digested with ClaI and 5′ protruding ends were filled using Klenow enzyme. The DNA was then digested with PacI and isolated from agarose gel. pWE/AflII-rITR was digested with EcoRI and after treatment with Klenow enzyme digested with PacI. The large 24 kb fragment containing the adenoviral sequences was isolated from agarose gel and ligated to the ClaI-digested and blunted pWE.pac vector using the Ligation Express™ kit from Clontech. After transformation of Ultracompetent XL10-Gold cells from Stratagene, clones were identified that contained the expected insert. pWE/AflII-EcoRI contains Ad5 sequences from bp 3534-27336.
Generation of pWE/Ad.AflII-rITRsp
The 3′ ITR in the vector pWE/Ad.AflII-rITR does not include the terminal G-nucleotide. Furthermore, the PacI site is located almost 30 bp from the right ITR. Both these characteristics may decrease the efficiency of virus generation due to inefficient initiation of replication at the 3′ ITR. Note that during virus generation, the left ITR in the adapter plasmid is intact and enables replication of the virus DNA after homologous recombination.
To improve the efficiency of initiation of replication at the 3′ ITR, the pWE/Ad.AflII-rITR was modified as follows: construct pBr/Ad.Bam-rITRpac#2 was first digested with PacI and then partially digested with AvrII and the 17.8 kb vector containing fragment was isolated and dephosphorylated using SAP enzyme (Boehringer Mannheim). This fragment lacks the adenovirus sequences from nucleotide 35464 to the 3′ ITR. Using DNA from pWE/Ad.AflII-rITR as template and the primers ITR-EPH: 5′-CGG AAT TCT TAA TTA AGT TAA CAT CAT CAA TAATAT ACC-3′ (SEQ ID NO:4) and Ad101: 5′-TGATTC ACATCG GTC AGT GC-3′ (SEQ ID NO:5).
A 630 bp PCR fragment was generated corresponding to the 3′ Ad5 sequences. This PCR fragment was subsequently cloned in the vector pCR2.1 (Invitrogen) and clones containing the PCR fragment were isolated and sequenced to check correct DNA amplification. The PCR clone was then digested with PacI and AvrII and the 0.5 kb adeno insert was ligated to the PacI/partial AvrII-digested pBr/Ad.Bam-rITRpac#2 fragment generating pBr/Ad.Bam-rITRsp. Next, this construct was used to generate a cosmid clone (as previously described herein) that has an insert corresponding to the adenovirus sequences 3534 to 35938. This clone was designated pWE/AflII-rITRsp.
Generation of pWE/Ad.AflII-rITRΔE2A:
Deletion of the E2A coding sequences from pWE/Ad.AflII-rITR (ECACC deposit P97082116) has been accomplished as follows. The adenoviral sequences flanking the E2A coding region at the left and the right site were amplified from the plasmid pBr/Ad.Sal.rITR (ECACC deposit P97082119) in a PCR reaction with the Expand PCR system (Boehringer) according to the manufacturer's protocol. The following primers were used:
Right flanking sequences (corresponding Ad5 nucleotides 24033 to 25180): ΔE2A.SnaBI: 5′-GGC GTA CGT AGC CCT GTC GAA AG-3′ (SEQ ID NO:6) and ΔE2A.DBP-start: 5′-CCA ATG CAT TCG AAG TAC TTC CTT CTC CTA TAG GC-3′ (SEQ ID NO:7). The amplified DNA fragment was digested with SnaBI and NsiI (NsiI site is generated in the primer ΔE2A.DBP-start, underlined).
Left flanking sequences (corresponding Ad5 nucleotides 21557 to 22442): ΔE2A.DBP-stop: 5′-CCA ATG CAT ACG GCG CAG ACG G-3′ (SEQ ID NO:8) and ΔE2A.BamHI: 5′-GAG GTG GAT CCC ATG GAC GAG-3′ (SEQ ID NO:9).
The amplified DNA was digested with BamHI and NsiI (NsiI site is generated in the primer ΔE2A.DBP-stop, underlined). Subsequently, the digested DNA fragments were ligated into SnaBI/BamHI-digested pBr/Ad.Sal-rITR. Sequencing confirmed the exact replacement of the DBP coding region with a unique NsiI site in plasmid pBr/Ad.Sal-rITRΔE2A. The unique NsiI site can be used to introduce an expression cassette for a gene to be transduced by the recombinant vector.
The deletion of the E2A coding sequences was performed such that the splice acceptor sites of the 100K encoding LA-gene at position 24048 in the top strand was left intact. In addition, the poly-adenylation signals of the original E2A-RNA and L3-RNAs at the left hand site of the E2A coding sequences were left intact. This ensures proper expression of the L3-genes and the gene encoding the 100K L-protein during the adenovirus life cycle.
Next, the plasmid pWE/Ad.AflII-rITRΔE2A was generated. The plasmid pBr/Ad.Sal-rITRΔE2A was digested with BamHI and SpeI. The 3.9 Kb fragment in which the unique NsiI site replaced the E2A coding region was isolated. The pWE/Ad.AflII-rITR was digested with BamHI and SpeI. The 35 Kb DNA fragment, from which the BamHI/SpeI fragment containing the E2A coding sequence was removed, was isolated. The fragments were ligated and packaged using λ phage-packaging extracts according to the manufacturer protocol (Stratagene), yielding the plasmid pWE/Ad.AflII-rITRΔE2A.
This cosmid clone can be used to generate adenoviral vectors that are deleted for E2A by co-transfection of PacI-digested DNA together with digested adapter plasmids onto packaging cells that express functional E2A gene product.
Construction of Adapter Plasmids
The absence of sequence overlap between the recombinant adenovirus and E1 sequences in the packaging cell line is essential for safe, RCA-free generation and propagation of new recombinant viruses. The adapter plasmid pMLPI.TK (described in U.S. Pat. No. 5,994,128 to Bout et al.) is an example of an adapter plasmid designed for use according to the invention in combination with the improved packaging cell lines of the invention. This plasmid was used as the starting material to make a new vector in which nucleic acid molecules comprising specific promoter and gene sequences can be easily exchanged.
First, a PCR fragment was generated from pZipΔMo+PyF101(N − ) template DNA (described in PCT/NL96/00195) with the following primers: LTR-1: 5′-CTG TAC GTA CCA GTG CAC TGG CCT AGG CAT GGA AAA ATA CAT AAC TG-3′ (SEQ ID NO:10) and LTR-2: 5′-GCG GAT CCT TCG AAC CAT GGT AAG CTT GGT ACC GCT AGC GTT AAC CGG GCG ACT CAG TCA ATC G-3′ (SEQ ID NO:11). Pwo DNA polymerase (Boehringer Mannheim) was used according to manufacturer's protocol with the following temperature cycles: once five minutes at 95° C.; three minutes at 55° C.; and one minute at 72° C., and 30 cycles of one minute at 95° C., one minute at 60° C., one minute at 72° C., followed by once ten minutes at 72° C. The PCR product was then digested with BamHI and ligated into pMLP10 (Levrero et al., 1991) vector digested with PvuII and BamHI, thereby generating vector pLTR10. This vector contains adenoviral sequences from bp 1 up to bp 454 followed by a promoter consisting of a part of the Mo-MuLV LTR having its wild-type enhancer sequences replaced by the enhancer from a mutant polyoma virus (PyF101). The promoter fragment was designated L420. Next, the coding region of the murine HSA gene was inserted. pLTR10 was digested with BstBI followed by Klenow treatment and digestion with NcoI. The HSA gene was obtained by PCR amplification on pUC18-HSA (Kay et al., 1990) using the following primers: HSA1, 5′-GCG CCA CCA TGG GCA GAG CGA TGG TGG C-3′ (SEQ ID NO:12) and HSA2,5′-GTT AGA TCT AAG CTT GTC GAC ATC GAT CTA CTA ACA GTA GAG ATG TAG AA-3′ (SEQ ID NO:13). The 269 bp amplified fragment was subcloned in a shuttle vector using the NcoI and BglII sites. Sequencing confirmed incorporation of the correct coding sequence of the HSA gene, but with an extra TAG insertion directly following the TAG stop codon. The coding region of the HSA gene, including the TAG duplication was then excised as a NcoI(sticky)-SalI(blunt) fragment and cloned into the 3.5 kb NcoI(sticky)/BstBI(blunt) fragment from pLTR10, resulting in pLTR-HSA10.
Finally, pLTR-HSA10 was digested with EcoRI and BamHI after which the fragment containing the left ITR, packaging signal, L420 promoter and HSA gene was inserted into vector pMLPI.TK digested with the same enzymes and thereby replacing the promoter and gene sequences. This resulted in the new adapter plasmid pAd/L420-HSA that contains convenient recognition sites for various restriction enzymes around the promoter and gene sequences. SnaBI and AvrII can be combined with HpaI, NheI, KpnI, HindIII to exchange promoter sequences, while the latter sites can be combined with the ClaI or BamHil sites 3′ from HSA coding region to replace genes in this construct.
Replacing the promoter, gene and poly-A sequences in pAd/L420-HSA with the CMV promoter, a multiple cloning site, an intron and a poly-A signal made another adapter plasmid that was designed to allow easy exchange of nucleic acid molecules. For this purpose, pAd/L420-HSA was digested with AvrII and BglII followed by treatment with Klenow to obtain blunt ends. The 5.1 kb fragment with pBr322 vector and adenoviral sequences was isolated and ligated to a blunt 1570 bp fragment from pcDNAl/amp (Invitrogen) obtained by digestion with Hhal and AvrII followed by treatment with T4 DNA polymerase. This adapter plasmid was designated pAdS/CLIP.
To enable removal of vector sequences from the left ITR in pAdS/Clip, this plasmid was partially digested with EcoRI and the linear fragment was isolated. An oligo of the sequence 5′ TTAAGTCGAC-3′ (SEQ ID NO:14) was annealed to itself resulting in a linker with a SalI site and EcoRI overhang. The linker was ligated to the partially digested pAdS/Clip vector and clones were selected that had the linker inserted in the EcoRI site 23 bp upstream of the left adenovirus ITR in pAd5/Clip resulting in pAd5/Clipsal. Likewise, the EcoRI site in pAd5/Clip has been changed to a PacI site by insertion of a linker of the sequence 5′-AATTGTCTTAATTAACCGCAATT-3′ (SEQ ID NO:15). The pAd5/Clip vector was partially digested with EcoRI, dephosphorylated and ligated to the PacI linker with EcoRI overhang. The ligation mixture was digested with PacI to remove concatamers, isolated from agarose gel and religated. The resulting vector was designated pAd5/Clippac. These changes enable more flexibility to liberate the left ITR from the plasmid vector sequences.
The vector pAd5/L420-HSA was also modified to create a SalI or PacI site upstream of the left ITR. Hereto pAd5/L420-HSA was digested with EcoRI and ligated to the previously herein described PacI linker. The ligation mixture was digested with PacI and religated after isolation of the linear DNA from agarose gel to remove concatamerized linkers. This resulted in adapter plasmid pAd5/L420-HSApac. This construct was used to generate pAd5/L420-HSAsal as follows: pAd5/L420-HSApac was digested with ScaI and BsrGI and the vector fragment was ligated to the 0.3 kb fragment isolated after digestion of pAd5/Clipsal with the same enzymes.
Generation of Adapter Plasmids pAdMire and pAdApt
To create an adapter plasmid that only contains a polylinker sequence and no promoter or polyA sequences, pAd5/L420-HSApac was digested with AvrII and BglII. The vector fragment was ligated to a linker oligonucleotide digested with the same restriction enzymes. Annealing oligos of the following sequence made the linker: PLL-1: 5′-GCC ATC CCT AGG AAG CTT GGT ACC GGT GAA TTC GCT AGC GTT AAC GGA TCC TCT AGA CGA GAT CTG G-3′ (SEQ ID NO:16) and PLL-2: 5′-CCA GAT CTC GTC TAG AGG ATC CGT TAA CGC TAG CGA ATT CAC CGG TAC CAA GCT TCC TAG GGA TGG C-3′ (SEQ ID NO:17). The annealed linkers were digested with AvrII and BglII and separated from small ends by column purification (Qiaquick nucleotide removal kit) according to manufacturer's recommendations. The linker was then ligated to the AvrII/BglII-digested pAd5/L420-HSApac fragment. A clone, designated AdMire, was selected that had the linker incorporated and was sequenced to check the integrity of the insert.
Adapter Plasmid AdMire Enables Easy Insertion of Complete Expression Cassettes
An adapter plasmid containing the human CMV promoter that mediates high expression levels in human cells was constructed as follows: pAd5/L420-HSApac was digested with AvrII and 5′ protruding ends were filled in using Klenow enzyme. A second digestion with HindRIII resulted in removal of the L420 promoter sequences. The vector fragment was isolated and ligated to a PCR fragment containing the CMV promoter sequence. This PCR fragment was obtained after amplification of CMV sequences from pCMVLacI (Stratagene) with the following primers: CMVplus: 5′-GATCGGTACCACTGCAGTGGTCAATATTGGCCATTAGCC-3′ (SEQ ID NO:18) and CMVminA: 5′-GATCAAGCTTCCAATGCACCGTTCCCGGC-3′ (SEQ ID NO:19).
The PCR fragment was first digested with PstI (underlined in CMVplus) after which the 3′-protruding ends were removed by treatment with T4 DNA polymerase. Then the DNA was digested with HindIII (underlined in CMVminA) and ligated into the herein described pAd5/LA20-HSApac vector fragment digested with AvrII and HindIII. The resulting plasmid was designated pAd5/CMV-HSApac. This plasmid was then digested with HindIII and BamHI and the vector fragment was isolated and ligated to the polylinker sequence obtained after digestion of AdMire with HindIII and BglII. The resulting plasmid was designated pAdApt. Adapter plasmid pAdApt contains nucleotides −735 to +95 of the human CMV promoter (Boshart et al., 1985). A second version of this adapter plasmid containing a SalI site in place of the PacI site upstream of the left ITR was made by inserting the 0.7 kb ScaI-BsrGI fragment from pAd5/Clipsal into pAdApt digested with ScaI and partially digested with BsrGI. This clone was designated pAdApt.sal.
Generation of Recombinant Adenoviruses Based on Ad5
RCA-free recombinant adenoviruses can be generated very efficiently using the herein described adapter plasmids and the pWe/Ad.AflII-rITR or pWE/Ad.AflII-rITrsp constructs. Generally, the adapter plasmid containing the desired transgene in the desired expression cassette is digested with suitable enzymes to liberate the insert from vector sequences at the 3′ and/or at the 5′ end. The adenoviral complementation plasmids pWE/Ad.AflII-rITR or pWE/Ad.AflII-rITRsp are digested with PacI to liberate the adeno sequences from the vector plasmids. As a non-limiting example, the generation of AdApt-LacZ is described. Adapter plasmid pAdApt-LacZ was generated as follows. The E. coli LacZ gene was amplified from the plasmid pMLP.nlsLacZ (EP 95-202 213) by PCR with the primers 5′-GGGGTGGCCAGGGTACCTCTAGGCTTTTGCAA-3′ (SEQ ID NO:20) and 5′-GGGGGGATCCATAAACAAGTTCAGAATCC-3′ (SEQ ID NO:21). The PCR reaction was performed with Ex Taq (Takara) according to the suppliers protocol at the following amplification program: five minutes 94° C., one cycle; 45 seconds 94° C. and 30 seconds 60° C. and two minutes 72° C., five cycles; 45 seconds 94° C. and 30 seconds 65° C. and two minutes 72° C., 25 cycles; ten minutes 72; 45 seconds 94° C. and 30 seconds 60° C. and two minutes 72° C., five cycles, I cycle. The PCR product was subsequently digested with Kpn1 and BamHI and the digested DNA fragment was ligated into KpnI/BamHI-digested pcDNA3 (Invitrogen), giving rise to pcDNA3.nlsLacZ. Construct pcDNA3.nlsLacZ was then digested with KpnI and BamHlI and the 3 kb LacZ fragment was isolated from gel using the GENECLEAN spin kit (Bio 101, Inc.). pAdApt was also digested with KpnI and BamHI and the linear vector fragment was isolated from gel as above. Both isolated fragments were ligated and one clone containing the LacZ insert was selected. Construct pAdApt-LacZ was digested with SalI, purified by the GENECLEAN spin kit and subsequently digested with PacI. pWE/Ad.AflII-rITRsp was digested with PacI. Both digestion mixtures were treated for 30 minutes by 65° C. to inactivate the enzymes. Samples were put on gel to estimate the concentration. 2.5×10 6 PER.C6 cells were seeded in T25 flasks in DMEM with 10% FCS and 10 mM MgCl. The next day, four microgram of each plasmid was transfected into PER.C6 cells using lipofectamine transfection reagents (Life Technologies Inc.) according to instructions of the manufacturer. The next day, the medium was replaced by fresh culture medium and cells were further cultured at 37° C., 10% CO 2 . Again, one day later, cells were trypsinized, seeded into T80 flasks and cultured at 37° C., 10% CO 2 . Full CPE was obtained 6 days after seeding in the T80 flask. Cells were harvested in the medium and subjected to one freeze/thaw cycle. The crude lysate obtained this way was used to plaque-purify the mixture of viruses. Ten plaques were picked, expanded in a 24-well plate and tested for LacZ expression following infection of A549 cells. Viruses from all ten plaques expressed LacZ.
Example 3
Generation of Chimeric Recombinant Adenoviruses
Generation of Hexon Chimeric Ad5-based Adenoviruses
Neutralizing antibodies in human serum are mainly directed to the hexon protein and to a lesser extend to the penton protein. Hexon proteins from different serotypes show highly variable regions present in loops that are predicted to be exposed at the outside of the virus (Athappilly et al., 1994 ; J. Mol. Biol. 242, 430-455). Most type-specific epitopes have been mapped to these highly variable regions (Toogood et al., 1989 ; J. Gen Virol. 70, 3203-3214). Thus, replacement of (part of) the hexon sequences with corresponding sequences from a different serotype is an effective strategy to circumvent (pre-existing) neutralizing antibodies to Ad5. Hexon coding sequences of Ad5 are located between nucleotides 18841 and 21697.
To facilitate easy exchange of hexon coding sequences from alternative adenovirus serotypes into the Ad5 backbone, first a shuttle vector was generated. This sub-clone, coded pBr/Ad.Eco-PmeI, was generated by first digesting plasmid pBr322 with EcoRI and EcoRV and inserting the 14 kb PmeI-EcoRI fragment from pWE/Ad.AflII-Eco. In this shuttle vector a deletion was made of a 1430 bp SanDI fragment by digestion with SanDI and re-ligation to give pBr/Ad.Eco-PmeI ΔSanDI. The removed fragment contains unique SpeI and MunI sites. From pBr/Ad.Eco-PmeIΔSanDI the Ad5 DNA encoding hexon was deleted. Hereto, the hexon flanking sequences were PCR amplified and linked together thereby generating unique restriction sites replacing the hexon coding region. For these PCR reactions four different oligonucleotides were required: Δhex1-Δhex4: Δhex1: 5′-CCT GGT GCT GCC AAC AGC-3′ (SEQ.I.D.NO.22), Δhex2: 5′-CCG GAT CCA CTA GTG GAA AGC GGG CGC GCG-3′ (SEQ ID NO:23), Δhex3: 5′-CCG GAT CCA ATT GAG AAG CAA GCA ACA TCA ACA AC-3′ (SEQ ID NO:24), and Δhex4: 5′-GAG AAG GGC ATG GAG GCT G-3′ (SEQ ID NO:25).
The amplified DNA product of ±1100 bp obtained with oligonucleotides Δhex1 and Δhex2 was digested with BamHI and FseI. The amplified DNA product of ±1600 bp obtained with oligonucleotides Δhex3 and Δhex4 was digested with BamHI and SbfI. These digested PCR fragments were subsequently purified from agarose gel and in a tri-part ligation reaction using T4 ligase enzyme linked to pBr/Ad.Eco-PmeI ΔSanDI digested with FseI and SbfI. The resulting construct was coded pBr/Ad.Eco-PmeΔHexon. This construct was sequenced in part to confirm the correct nucleotide sequence and the presence of unique restriction sites MunI and SpeI.
pBr/Ad.Eco-PmeΔHexon serves as a shuttle vector to introduce heterologous hexon sequences amplified from virus DNA from different serotypes using primers that introduce the unique restriction sites MunI and SpeI at the 5′ and 3′ ends of the hexon sequences respectively. To generate Ad5-based vectors that contain hexon sequences from the serotypes to which healthy individuals have no, or very low, titers of NAB the hexon sequences of Ad35, Ad34, Ad26 and Ad48 were amplified using the following primers: Hex-up2: 5′-GACTAGTCAAGATGGCYACCCCHTCGATGATG-3′ (SEQ ID NO:26) (where Y can be a C or T and H can be an A, T or C as both are degenerate oligo nucleotides) and Hex-do2: 5′-GCTGGCCAATTGTTATGTKGTKGCGTTRCCGGC-3′ (SEQ ID NO:27) (where K can be a T or G and R can be an A or G as both are degenerate oligo nucleotides).
These primers were designed using the sequences of published hexon coding regions (for example hexon sequences of Ad2, Ad3, Ad4, Ad5, Ad7, Ad16, Ad40 and Ad41 can be obtained at Genbank). Degenerated nucleotides were incorporated at positions that show variation between serotypes.
PCR products were digested with SpeI and MunI and cloned into the pBr/Ad.Eco-PmeΔHexon construct digested with the same enzymes.
The hexon modified sequences were subsequently introduced in the construct pWE/Ad.AflII-rITR by exchange of the AscI fragment generating pWE/Ad.AflII-rITRHexXX where XX stands for the serotype used to amplify hexon sequences.
The pWE/Ad.AflII-rITRHexXX constructs were then used to make viruses in the same manner as previously described herein for Ad5 recombinant viruses.
Generation of Penton Chimeric Ad5-Based Recombinant Viruses
The adenovirus type 5 penton gene is located between sequences 14156 and 15869. Penton base is the adenovirus capsid protein that mediates internalization of the virus into the target cell. At least some serotypes (type C and B) have been shown to achieve this by interaction of an RGD sequence in penton with integrins on the cell surface. However, type F adenoviruses do not have an RGD sequence and for most viruses of the A and D group the penton sequence is not known. Therefore, the penton may be involved in target cell specificity. Furthermore, as a capsid protein, the penton protein is involved in the immunogenicity of the adenovirus (Gahery-Segard et al., 1998). Therefore, replacement of Ad5 penton sequences with penton sequences from serotypes to which no or low titers of NAB exist in addition to replacement of the hexon sequences will prevent clearance of the adenoviral vector more efficiently than replacement of hexon alone. Replacement of penton sequences may also affect infection specificity.
To be able to introduce heterologous penton sequences in Ad5 we made use of the plasmid-based system described above. First, a shuttle vector for penton sequences was made by insertion of the 7.2 kb NheI-EcoRV fragment from construct pWE/Ad.AflII-EcoRI into pBr322 digested with the same enzymes. The resulting vector was designated pBr/XN. From this plasmid, Ad5 penton sequences were deleted and replaced by unique restriction sites that were then used to introduce new penton sequences from other serotypes. Hereto, the left flanking sequences of penton in pBr/XN were PCR amplified using the following primers: DP5-F: 5′-CTG TTG CTG CTG CTA ATA GC-3′ (SEQ ID NO:28) and DP5-R: 5′-CGC GGA TCC TGT ACA ACT AAG GGG AAT ACA AG-3′ (SEQ ID NO:29).
DP5-R has a BamHI site (underlined) for ligation to the right flanking sequence and also introduces a unique BsrGI site (bold face) at the 5′-end of the former Ad5 penton region. The right flanking sequence was amplified using: DP3-F: 5′-CGC GGA TCC CTT AAG GCA AGC ATG TCC ATC CTT-3′ (SEQ ID NO:30) and DP3-3R: 5′-AAA ACA CGT TTT ACG CGT CGA CCT TTC-3′ (SEQ ID NO:31). DP3-F has a BamHI site (underlined) for ligation to the left flanking sequence and also introduces a unique AflII site (bold face) at the 3′ end of the former Ad5 penton region.
The two resulting PCR fragments were digested with BamHI and ligated together. Then this ligation mixture was digested with AvrII and BglII. pBr/XN was also digested with AvrII and BglII and the vector fragment was ligated to the digested ligated PCR fragments. The resulting clone was designated pBr/Ad.Δpenton. Penton coding sequences from Ad35, Ad34, Ad26 and Ad48 were PCR amplified such that the 5′ and 3′ ends contained the BsrGI and AflII sites respectively. Hereto, the following primers were used:
For Ad34 and Ad35:
P3-for:
(SEQ ID NO:32)
5′-GCT CGA TGT ACA ATG AGG AGA CGA GCC GTG CTA-3′
and
P3-rev:
(SEQ ID NO:33)
5′-GCT CGA CTT AAG TTA GAA AGT GCG GCT TGA AAG-3′.
For Ad26 and Ad48:
P17F:
(SEQ ID NO:34)
5′-GCT CGA TGT ACA ATG AGG CGT GCG GTG GTG TCT
TC-3′
and
P17R:
(SEQ ID NO:35)
5′-GCT CGA CTT AAG TTA GAA GGT GCG ACT GGA AAG
C-3′.
Amplified PCR products were digested with BfrI and BsrGI and cloned into pBr/Ad.Δpenton digested with the same enzymes. Introduction of these heterologous penton sequences into the pBr/Ad.Δpenton generated constructs designated pBr/Ad.pentonXX, wherein XX represents the number of the serotype corresponding to the serotype used to amplify the inserted penton sequences. Subsequently, the new penton sequences were introduced in the pWE/Ad.AfllII-rITR vector having a modified hexon. For example, penton sequences from Ad35 were introduced in the construct pWE/Ad.AflII-rITRHex35 by exchange of the common FseI fragment. Other combinations of penton and hexon sequences were also made. Viruses with modified hexon and penton sequences were made as described above using cotransfection with an adapter plasmid on PER.C6 cells. In addition, penton sequences were introduced in the pWE/Ad.AflII-rITR construct. The latter constructs contain only a modified penton, and viruses generated from these constructs will be used to study the contribution of penton sequences to the neutralization of adenoviruses and also for analysis of possible changes in infection efficiency and specificity.
Generation of Fiber Chimeric Ad5-Based Viruses
Adenovirus infection is mediated by two capsid proteins fiber and penton. Binding of the virus to the cells is achieved by interaction of the protruding fiber protein with a receptor on the cell surface. Internalization then takes place after interaction of the penton protein with integrins on the cell surface. At least some adenovirus from subgroups C and B have been shown to use a different receptor for cell binding and, therefore, have different infection efficiencies on different cell types. Thus, it is possible to change the infection spectrum of adenoviruses by changing the fiber in the capsid. The fiber coding sequence of Ad5 is located between nucleotides 31042 and 32787. To remove the Ad5 DNA encoding fiber, we started with construct pBr/Ad.Bam-rITR. First, an NdeI site was removed from this construct. For this purpose, pBr322 plasmid DNA was digested with NdeI. After which, protruding ends were filled using Klenow enzyme. This pBr322 plasmid was then re-ligated, digested with NdeI, and transformed into E. coli DH5α. The obtained pBr/ΔNdeI plasmid was digested with ScaI and SalI and the resulting 3198 bp vector fragment was ligated to the 15349 bp ScaI-SalI fragment derived from pBr/Ad.BamrITR, resulting in plasmid pBr/Ad.Bam-rITRΔNdeI which hence contained a unique NdeI site. Next, a PCR was performed with oligonucleotides NY-up: 5′-CGA CAT ATG TAG ATG CAT TAG TTT GTG TTA TGT TTC AAC GTG-3′ (SEQ ID NO:36) and NY-down: 5′-GGA GAC CAC TGC CAT GTT-3′ (SEQ ID NO:37).
During amplification, both an NdeI (bold face) and an NsiI restriction site (underlined) were introduced to facilitate cloning of the amplified fiber DNAs. Amplification consisted of 25 cycles of each 45 seconds at 94° C., one minute at 60° C., and 45 seconds at 72° C. The PCR reaction contained 25 pmol of oligonucleotides NY-up or NY-down, 2 mM dNTP, PCR buffer with 1.5 mM MgCl 2 , and 1 unit of Elongase heat stable polymerase (Gibco, The Netherlands). One-tenth of the PCR product was run on an agarose gel that demonstrated that the expected DNA fragment of ±2200 bp was amplified. This PCR fragment was subsequently purified using GENECLEAN kit system (Bio 101 Inc.). Then, both the construct pBr/Ad.Bam-rITRΔNdeI, as well as the PCR product, were digested with restriction enzymes NdeI and SbfI. The PCR fragment was subsequently cloned using T4 ligase enzyme into the NdeI- and SbfI-digested pBr/Ad.Bam-rITRΔNdeI, generating pBr/Ad.BamRΔFib.
This plasmid allows insertion of any PCR-amplified fiber sequence through the unique NdeI and NsiI sites that are inserted in place of the removed fiber sequence. Viruses can be generated by a double homologous recombination in packaging cells described in U.S. Pat. No. 5,994,128 to Bout et al. using an adapter plasmid, construct pBr/Ad.AflII-EcoRI digested with PacI and EcoRI and a pBr/Ad.BamRΔFib construct in which heterologous fiber sequences have been inserted. To increase the efficiency of virus generation, the construct pBr/Ad.BamRΔFib was modified to generate a PacI site flanking the right ITR. Hereto, pBr/Ad.BamRΔFib was digested with AvrII and the 5 kb adenovirus fragment was isolated and introduced into the vector pBr/Ad.Bam-rITR.pac#8 described above replacing the corresponding AvrII fragment. The resulting construct was designated pBr/Ad.BamRΔFib.pac.
Once a heterologous fiber sequence is introduced in pBr/Ad.BamRΔFib.pac, the fiber-modified right hand adenovirus clone is introduced into a large cosmid clone as previously described herein for pWE/Ad.AflII-rITR. Such a large cosmid clone allows generation of adenovirus by only one homologous recombination. Ad5-based viruses with modified fibers have been made and described (see, European Patent Appln. Nos. 98204482.8 and 99200624.7). In addition, hexon and penton sequences from serotypes from this invention are combined with the desired fiber sequences to generate viruses that infect the target cell of choice very efficiently. For example, smooth muscle cells, endothelial cells or synoviocytes (all from human origin) are very well infected with Ad5-based viruses with a fiber from subgroup B viruses, especially Ad16.
The foregoing examples in which specific sequences can be deleted from the Ad5 backbone in the plasmids and replaced by corresponding sequences from other serotypes demonstrate the flexibility of the system. It is evident that by the methods described herein, any combination of capsid gene from different serotypes can be made. Thus, chimeric recombinant Ad5-based adenoviruses are designed with desired hexon and penton sequences making the virus less sensitive for neutralization and with desired fiber sequences allowing efficient infection in specific target tissues.
Example 4
Construction of a Plasmid-based System to Generate Ad35 Recombinant Viruses
Partial restriction maps of Ad35 have been published previously (Valderrama-Leon et al., 1985; Kang et al., 1989; Li et al., 1991). An example of a functional plasmid-based system to generate recombinant adenoviruses based on Ad35 consists of the following elements:
1. An adapter plasmid comprising a left ITR and packaging sequences derived from Ad35 and at least one restriction site for insertion of a heterologous expression cassette and lacking E1 sequences. Furthermore, the adapter plasmid contains Ad35 sequences 3′ from the E1B coding region including the pIX promoter and coding sequences sufficient to mediate homologous recombination of the adapter plasmid with a second nucleotide.
2. A second nucleotide comprising sequences homologous to the adapter plasmid and Ad35 sequences necessary for the replication and packaging of the recombinant virus, that is, early, intermediate and late genes that are not present in the packaging cell.
3. A packaging cell providing at least functional E1 proteins and proteins capable of complementing the E1 function of Ad35.
Ad35 DNA was isolated from a purified virus batch as follows. To 100 μl of virus stock (Ad35: 3.26×10 12 VP/ml), 10 μl 10× DNAse buffer (130 mM Tris-HCl pH7.5; 1,2 M CaCl 2 ; 50 mM MgCl 2 ) was added. After addition of 10 μl 10 mgr/ml DNAse I (Roche Diagnostics), the mixture was incubated for one hour at 37° C. Following addition of 2.5 μl 0.5M EDTA, 3.2 μl 20% SDS and 1.5 μl ProteinaseK (Roche Diagnostics; 20 mgr/ml), samples were incubated at 50° C. for one hour. Next, the viral DNA was isolated using the GENECLEAN spin kit (Bio101 Inc.) according to the manufacturer's instructions. DNA was eluted from the spin column with 25 μl sterile MilliQ water.
In the following, sizes of DNA fragments and fragment numbering will be used according to Kang et al. (1989). Ad35 DNA was digested with EcoRI and the three fragments (approximately 22.3 (A), 7.3 (B) and 6 kb (C)) were isolated from gel using the GENECLEAN kit (Bio101, Inc.). pBr322 was digested with EcoRI or with EcoRI and EcoRV and digested fragments were isolated from gel and dephosphorylated with Tsap enzyme (Gibco BRL). Next, the 6 kb Ad35 C fragment was ligated to the pBr322xEcoRI fragment and the ITR-containing Ad35 fragment (EcoRI-B) was ligated to the pBr322xEcoRI/EcoRV fragment. Ligations were incubated at 16° C. overnight and transformed into DH5α competent bacteria (Life Techn.). Minipreps of obtained colonies were analyzed for correct insertion of the Ad35 fragments by restriction analysis. Both the 6 kb and the 7.3 kb Ad35 fragments were found to be correctly inserted in pBr322. The 6 kb fragment was isolated in both orientations pBr/Ad35-Eco6.0 + and pBr/Ad35-Eco6.0 − , whereby the +stands for 5′ to 3′ orientation relative to pBr322. The clone with the 7.3 kb Ad35 B insert, designated pBr/Ad35-Eco7.3 was partially sequenced to check correct ligation of the 3′ ITR. It was found that the ITR had at least the sequence 5′-CATCATCAAT . . . -3′ found in SEQ ID NO:40 in the lower strand. Then pBr/Ad35-Eco7.3 was extended to the 5′ end by insertion of the 6 kb Ad35 fragment. Hereto, pBr/Ad35-Eco7.3 was digested with EcoRI and dephosphorylated. The fragment was isolated from gel and ligated to the 6 kb Ad35 EcoRI fragment. After transformation clones were tested for correct orientation of the insert and one clone was selected, designated pBr/Ad35-Eco13.3.
This clone was then extended with the ˜5.4 kb SalI D fragment obtained after digestion of wt Ad35 with SalI. Hereto, the SalI site in the pBr322 backbone was removed by partial digestion of pBr/Ad35-Eco13.3 with SalI, filling in of the sticky ends by Klenow treatment and re-ligation. One clone was selected that contains a single SalI site in the adenoviral insert. This clone, designated pBrΔsal/Ad35-Eco13.3 was then linearized with AatII which is present in the pBr322 backbone and ligated to a SalI linker with AatII complementary ends. The DNA was then digested with excess SalI and the linear fragment was isolated and ligated to the 5.4 kb SalI-D fragment from Ad35. One clone was selected that contains the SalI fragment inserted in the correct orientation in pBr/Ad35-Eco13.3. The resulting clone, pBr/Ad35.Sal2-rITR contained the 3′˜17 kb of Ad35 including the right ITR. To enable liberation of the right ITR from the vector sequences at the time of virus generation, a NotI site flanking the right ITR was introduced by PCR.
The Ad35 EcoRI-A fragment of 22.3 kb was also cloned in pBr322xEcoRI/EcoRV. One clone, designated pBr/Ad35-EcoA3′, was selected that apparently had a deletion of approximately 7 kb of the 5′ end. It did contain the SalI site at 9.4 kb in Ad35 wt DNA and approximately 1.5 kb of sequences upstream. Using this SalI site and the unique NdeI site in the pBr322 backbone, this clone is extended to the 5′ end by insertion of an approximately 5 kb Ad35 fragment 5′ from the first SalI in Ad35 in such a way that a NotI restriction site was created at the 5′ end of the Ad35 by insertion of a linker. This clone, designated pBr/Ad35.pIX-EcoA, does not contain the left end sequences (ITR, packaging sequences and E1) and at the 3′ end it has approximately 3.5 kb overlap with clone pBr/Ad35.Sal2-rITR.
To create an adapter plasmid, Ad35 was digested with SalI and the left end B fragment of ˜9.4 kb was isolated. pBr322 was digested with EcoRV and SalI, isolated from gel and dephosphorylated with Tsap enzyme. Both fragments were ligated and clones with correct insertion and correct sequence of the left ITR were selected. To enable liberation of the left ITR from the vector sequences at the time of virus generation, a NotI site flanking the left ITR was introduced by PCR. From this clone, the E1 sequences were deleted and replaced by a polylinker sequence using PCR. The polylinker sequence is used to introduce an expression cassette for a gene of choice.
Recombinant Ad35 clones are generated by transfection of PER.C6 cells with the adapter plasmid, pBr/Ad35.pIX-EcoA and pBr/Ad35.Sal2-rITR as shown in FIG. 3 . Homologous recombination gives rise to recombinant viruses.
Example 5
The Prevalence of Neutralizing Activity (NA) to Ad35 is Low in Human Sera from Different Geographic Locations
In Example 1, the analysis of neutralizing activity (“NA”) in human sera from one location in Belgium was described. Strikingly, of a panel of 44 adenovirus serotypes tested, one serotype, Ad35, was not neutralized in any of the 100 sera assayed. In addition, a few serotypes, Ad26, Ad34 and Ad48 were found to be neutralized in 8%, or less, of the sera tested. This analysis was further extended to other serotypes of adenovirus not previously tested and, using a selection of serotypes from the first screen, was also extended to sera from different geographic locations.
Hereto, adenoviruses were propagated, purified and tested for neutralization in the CPE-inhibition assay as described in Example 1. Using the sera from the same batch as in Example 1, adenovirus serotypes 7B, 11, 14, 18 and 44/1876 were tested for neutralization. These viruses were found to be neutralized in, respectively, 59, 13, 30, 98 and 54% of the sera. Thus, of this series, Ad11 is neutralized with a relatively low frequency.
Since it is known that the frequency of isolation of adenovirus serotypes from human tissue as well as the prevalence of NA to adenovirus serotypes may differ on different geographic locations, we further tested a selection of the adenovirus serotypes against sera from different places. Human sera were obtained from two additional places in Europe (Bristol, UK and Leiden, NL) and from two places in the United States (Stanford, Calif. and Great Neck, N.Y.). Adenoviruses that were found to be neutralized in 20% or less of the sera in the first screen, as well as Ad2, Ad5, Ad27, Ad30, Ad38, Ad43, were tested for neutralization in sera from the UK. The results of these experiments are presented in FIG. 4 .
Adenovirus serotypes 2 and 5 were again neutralized in a high percentage of human sera. Furthermore, some of the serotypes that were neutralized in a low percentage of sera in the first screen are neutralized in a higher percentage of sera from the UK, e.g., Ad26 (7% vs. 30%), Ad28 (13% vs. 50%), Ad34 (5% vs. 27%) and Ad48 (8% vs. 32%). Neutralizing activity against Ad11 and Ad49 that were found in a relatively low percentage of sera in the first screen, were found in an even lower percentage of sera in this second screen (13% vs. 5% and 20% vs. 11%, respectively). Serotype Ad35 that was not neutralized in any of the sera in the first screen, was now found to be neutralized in a low percentage (8%) of sera from the UK. The prevalence of NA in human sera from the UK is the lowest to serotypes Ad11 and Ad35.
For further analysis, sera obtained from two locations in the US (Stanford, Calif. and Great Neck, N.Y.) and from The Netherlands (Leiden). FIG. 5 presents an overview of data obtained with these sera and the previous data. Not all viruses were tested in all sera, except for Ad5, Ad11 and Ad35. The overall conclusion from this comprehensive screen of human sera is that the prevalence of neutralizing activity to Ad35 is the lowest of all serotypes throughout the western countries: on average 7% of the human sera contain neutralizing activity (five different locations). Another B-group adenovirus, AdII is also neutralized in a low percentage of human sera (average 11% in sera from five different locations). Adenovirus type 5 is neutralized in 56% of the human sera obtained from five different locations. Although not tested in all sera, D-group serotype 49 is also neutralized with relatively low frequency in samples from Europe and from one location of the US (average 14%).
In the herein described neutralization experiments, a serum is judged non-neutralizing when, in the well with the highest serum concentration, the maximum protection of CPE is 40% compared to the controls without serum. The protection is calculated as follows:
% protection=OD corresponding well−OD virus control×100%
OD non-infected control−OD virus control
As described in Example 1, the serum is plated in five different dilutions ranging from 4× to 64× diluted. Therefore, it is possible to distinguish between low titers (i.e., neutralization only in the highest serum concentrations) and high titers of NA (i.e., also neutralization in wells with the lowest serum concentration). Of the human sera used in our screen that were found to contain neutralizing activity to Ad5, 70% turned out to have high titers whereas of the sera that contained NA to Ad35, only 15% had high titers. Of the sera that were positive for NA to Ad11 only 8% had high titers. For Ad49, this was 5%. Therefore, not only is the frequency of NA to Ad35, Ad 11 and Ad49 much lower as compared to Ad5, but of the sera that do contain NA to these viruses, the vast majority have low titers. Adenoviral vectors based on Ad11, Ad35 or Ad49 have, therefore, a clear advantage over Ad5 based vectors when used as gene therapy vehicles or vaccination vectors in vivo or in any application where infection efficiency is hampered by neutralizing activity.
In the following examples, the construction of a vector system for the generation of safe, RCA-free Ad35-based vectors is described.
Example 6
Sequence of the Human Adenovirus Type 35
Ad35 viruses were propagated on PER.C6 cells and DNA was isolated as described in Example 4. The total sequence was generated by Qiagen Sequence Services (Qiagen GmbH, Germany). Total viral DNA was sheared by sonification and the ends of the DNA were made blunt by T4 DNA polymerase. Sheared blunt fragments were size fractionated on agarose gels and gel slices corresponding to DNA fragments of 1.8 to 2.2 kb were obtained. DNA was purified from the gel slices by the QIAquick gel extraction protocol and subcloned into a shotgun library of pUC19 plasmid cloning vectors. An array of clones in 96-well plates covering the target DNA 8 (+/−2) times was used to generate the total sequence. Sequencing was performed on Perkin-Elmer 9700 thermocyclers using Big Dye Terminator chemistry and AmpliTaq FS DNA polymerase followed by purification of sequencing reactions using QIAGEN DyeEx 96 technology. Sequencing reaction products were then subjected to automated separation and detection of fragments on ABI377 XL 96 lane sequencers. Initial sequence results were used to generate a contig sequence and gaps were filled in by primer walking reads on the target DNA or by direct sequencing of PCR products. The ends of the virus turned out to be absent in the shotgun library, most probably due to cloning difficulties resulting from the amino acids of pTP that remain bound to the ITR sequences after proteinase K digestion of the viral DNA. Additional sequence runs on viral DNA solved most of the sequence in those regions, however it was difficult to obtain a clear sequence of the most terminal nucleotides. At the 5′ end the sequence portion obtained was 5′-CCAATAATATACCT-3′ (SEQ ID NO:38) while at the 3′ end, the obtained sequence portion was 5′-AGGTATATTATTGATGATGGG-3′ (SEQ ID NO:39). Most human adenoviruses have a terminal sequence 5′-CATCATCAATAATATACC-3′ (SEQ ID NO:40). In addition, a clone representing the 3′ end of the Ad35 DNA obtained after cloning the terminal 7 kb Ad35 EcoRI fragment into pBr322 (see, Example 4) also turned out to have the typical CATCATCAATAAT . . . sequence as seen in SEQ ID NO:40. Therefore, Ad35 may have the typical end sequence and the differences obtained in sequencing directly on the viral DNA are due to artifacts correlated with run-off sequence runs and the presence of residual amino acids of pTP.
The total sequence of Ad35 with corrected terminal sequences is given in FIG. 6 . Based upon sequence homology with Ad5 (Genbank # M72360) and Ad7 (partial sequence Genbank # X03000) and on the location of open reading frames, the organization of the virus is identical to the general organization of most human adenoviruses, especially the subgroup B viruses. The total length of the genome is 34,794 basepairs.
Example 7
Construction of a Plasmid-based Vector System to Generate Recombinant Ad35-based Viruses.
A functional plasmid-based vector system to generate recombinant adenoviral vectors comprises the following components:
1. An adapter plasmid comprising a left ITR and packaging sequences derived from Ad35 and at least one restriction site for insertion of a heterologous expression cassette and lacking E1 sequences. Furthermore, the adapter plasmid contains Ad35 sequences 3′ from the E1B coding region including the pIX promoter and coding sequences enough to mediate homologous recombination of the adapter plasmid with a second nucleic acid molecule.
2. A second nucleic acid molecule, comprising sequences homologous to the adapter plasmid, and Ad35 sequences necessary for the replication and packaging of the recombinant virus, that is, early, intermediate and late genes that are not present in the packaging cell.
3. A packaging cell providing at least functional E1 proteins capable of complementing the E1 function of Ad35.
Other methods for the generation of recombinant adenoviruses on complementing packaging cells are known in the art, and may be applied to Ad35 viruses without departing from the invention. As an example, the construction of a plasmid-based system, as outlined above, is described in detail below.
1) Construction of Ad35 Adapter Plasmids
Hereto, the adapter plasmid pAdApt ( FIG. 7 ; described in Example 2) was first modified to obtain adapter plasmids that contain extended polylinkers and that have convenient unique restriction sites flanking the left ITR and the adenovirus sequence at the 3′ end to enable liberation of the adenovirus insert from plasmid vector sequences. Construction of these plasmids is described below in detail:
Adapter plasmid pAdApt (Example 2) was digested with SalI and treated with Shrimp Alkaline Phosphatase to reduce religation. A linker, composed of the following two phosphorylated and annealed oligos: ExSalPacF 5′-TCG ATG GCA AAC AGC TAT TAT GGG TAT TAT GGG TTC GAA TTA ATT AA-3′ (SEQ ID NO:41); and ExSalPacR 5′-TCG ATT AAT TAA TTC GAA CCC ATA ATA CCC ATA ATA GCT GTT TGC CA-3′ (SEQ ID NO:42); was directly ligated into the digested construct, thereby replacing the SalI restriction site by Pi-PspI, Swal and PacI. This construct was designated pADAPT+ExSalPac linker. Furthermore, part of the left ITR of pAdApt was amplified by PCR using the following primers: PCLIPMSF: 5′-CCC CAA TTG GTC GAC CAT CAT CAA TAA TAT ACC TTA TTT TGG-3′ (SEQ ID NO:43) and pCLIPBSRGI: 5′-GCG AAA ATT GTC ACT TCC TGT G-3′ (SEQ ID NO:44). The amplified fragment was digested with MunI and BsrGI and cloned into pAd5/Clip (see, Example 2), which was partially digested with EcoRI and, after purification, digested with BsrGI, thereby re-inserting the left ITR and packaging signal. After restriction enzyme analysis, the construct was digested with ScaI and SgrAI and an 800 bp fragment was isolated from gel and ligated into ScaI/SgrAI-digested pADAPT+ExSalPac linker. The resulting construct, designated pIPspSalAdapt, was digested with SalI, dephosphorylated, and ligated to the phosphorylated ExSalPacF/ExSalPacR double-stranded linker previously mentioned. A clone in which the PacI site was closest to the ITR was identified by restriction analysis and sequences were confirmed by sequence analysis. This novel pAdApt construct, termed pIPspAdapt ( FIG. 8 ) thus harbours two ExSalPac linkers containing recognition sequences for PacI, PI-PspI and BstBI, which surround the adenoviral part of the adenoviral adapter construct, and which can be used to linearize the plasmid DNA prior to cotransfection with adenoviral helper fragments.
In order to further increase transgene cloning permutations, a number of polylinker variants were constructed based on pIPspAdapt. For this purpose, pIPspAdapt was first digested with EcoRI and dephosphorylated. A linker composed of the following two phosphorylated and annealed oligos: Ecolinker+: 5′-AAT TCG GCG CGC CGT CGA CGA TAT CGA TAG CGG CCG C-3′ (SEQ ID NO:45) and Ecolinker-: 5′-AAT TGC GGC CGC TAT CGA TAT CGT CGA CGG CGC GCC G-3′ (SEQ ID NO:46) was ligated into this construct, thereby creating restriction sites for AscI, SalI, EcoRV, ClaI and NotI. Both orientations of this linker were obtained, and sequences were confirmed by restriction analysis and sequence analysis. The plasmid containing the polylinker in the order 5′ HindIII, KpnI, Agel, EcoRI, AscI, SalI, EcoRV, ClaI, NotI, NheI, Hpal, BamHI and XbaI was termed pIPspAdapt1 ( FIG. 9 ), while the plasmid containing the polylinker in the order HindIII, KpnI, Agel, NotI, ClaI, EcoRV, SalI, AscI, EcoRI, NheI, HpaI, BamHI and XbaI was termed pIPspAdapt2.
To facilitate the cloning of other sense or antisense constructs, a linker composed of the following two oligonucleotides was designed, to reverse the polylinker of pIPspAdapt: HindXba+5′-AGC TCT AGA GGA TCC GTT AAC GCT AGC GAA TTC ACC GGT ACC AAG CTT A-3′ (SEQ ID NO:47); HindXba-5′-CTA GTA AGC TTG GTA CCG GTG AAT TCG CTA GCG TTA ACG GAT CCT CTA G-3′ (SEQ ID NO:48). This linker was ligated into HindIII/XbaI-digested pIPspAdapt and the correct construct was isolated. Confirmation was done by restriction enzyme analysis and sequencing. This new construct, pIPspAdaptA, was digested with EcoRI and the previously mentioned Ecolinker was ligated into this construct. Both orientations of this linker were obtained, resulting in pIPspAdapt3 ( FIG. 10 ), which contains the polylinker in the order XbaI, BamHI, HpaI, NheI, EcoRI, AscI, SalI, EcoRV, ClaI, NotI, Agel, KpnI and HindIII. All sequences were confirmed by restriction enzyme analysis and sequencing.
Adapter plasmids based on Ad35 were then constructed as follows:
The left ITR and packaging sequence corresponding to Ad35 wt sequences nucleotides 1 to 464 ( FIG. 6 ) were amplified by PCR on wtAd35 DNA using the following primers: Primer 35F1: 5′-CGG AAT TCT TAA TTA ATC GAC ATC ATC AAT AAT ATA CCT TAT AG-3′ (SEQ ID NO:49) and Primer 35R2: 5′-GGT GGT CCT AGG CTG ACA CCT ACG TAA AAA CAG-3′ (SEQ ID NO:50). Amplification introduces a PacI site at the 5′ end and an AvrII site at the 3′ end of the sequence.
For the amplification, Platinum Pfx DNA polymerase enzyme (LTI) was used according to manufacturer's instructions, but with primers at 0.6 μM and with DMSO added to a final concentration of 3%. Amplification program was as follows: two minutes at 94° C., (30 seconds at 94° C., 30 seconds at 56° C., one minute at 68° C.) for 30 cycles, followed by ten minutes at 68° C.
The PCR product was purified using a PVR purification kit (LTI) according to the manufacturer's instructions, and digested with PacI and AvrII. The digested fragment was then purified from gel using the GENECLEAN kit (Bio 101, Inc.). The Ad5-based adapter plasmid pIPspAdApt-3 ( FIG. 10 ) was digested with AvrII and then partially with PacI and the 5762 bp fragment was isolated in an LMP agarose gel slice and ligated with the abovementioned PCR fragment digested with the same enzymes and transformed into electrocompetent DH10B cells (LTI). The resulting clone is designated pIPspAdApt3-Ad3511TR.
In parallel, a second piece of Ad35 DNA was amplified using the following primers: 35F3: 5′-TGG TGG AGA TCT GGT GAG TAT TGG GAA AAC-3′ (SEQ ID NO:51) and 35R4: 5′-CGG AAT TCT TAA TTA AGG GAA ATG CAA ATC TGT GAG G-3′ (SEQ ID NO:52).
The sequence of this fragment corresponds to nucleotides 3401 to 4669 of wtAd35 ( FIG. 6 ) and contains 1.3 kb of sequences starting directly 3′ from the E1B 55k coding sequence. Amplification and purification were done as previously described herein for the fragment containing the left ITR and packaging sequence. The PCR fragment was then digested with PacI and subcloned into pNEB193 vector (New England Biolabs) digested with SmaI and PacI. The integrity of the sequence of the resulting clone was checked by sequence analysis. pNEB/Ad35 pF3R4 was then digested with BglII and PacI and the Ad35 insert was isolated from gel using the QIAExII kit (Qiagen). pIPspAdApt3-Ad3511TR was digested with BglII and then partially with PacI. The 3624 bp fragment (containing vector sequences, the Ad35 ITR and packaging sequences as well as the CMV promoter, multiple cloning region and polyA signal) was also isolated using the QIAExII kit (Qiagen). Both fragments were ligated and transformed into competent DH10B cells (LTI). The resulting clone, pAdApt35IP3 ( FIG. 11 ), has the expression cassette from pIPspAdApt3 but contains the Ad35 left ITR and packaging sequences and a second fragment corresponding to nucleotides 3401 to 4669 from Ad35. A second version of the Ad35 adapter plasmid having the multiple cloning site in the opposite orientation was made as follows:
pIPspAdapt1 ( FIG. 9 ) was digested with NdeI and BglII and the 0.7 kbp band containing part of the CMV promoter, the MCS and SV40 polyA was isolated and inserted in the corresponding sites of pAdApt35IP3 generating pAdApt35IP1 ( FIG. 12 ).
pAdApt35.LacZ and pAdApt35.Luc adapter plasmids were then generated by inserting the transgenes from pcDNA.LacZ (digested with KpnI and BamHI) and pAdApt.Luc (digested with HindIII and BamHI) into the corresponding sites in pAdApt35IP1. The generation of pcDNA.LacZ and pAdApt.Luc is described in International Patent Application WO99/55132.
Construction of Cosmid pWE.Ad35.pXI-rITR
FIG. 13 presents the various steps undertaken to construct the cosmid clone containing Ad35 sequences from bp 3401 to 34794 (end of the right ITR) that are described in detail below.
A first PCR fragment (pIX-NdeI) was generated using the following primer set:
35F5:
(SEQ D NO:53)
5′-CGG AAT TCG CGG CCG CGG TGA GTA TTG GGA AAA
C-3′
and
35R6:
(SEQ ID NO:54)
5′-CGC CAG ATC GTC TAC AGA ACA G-3′.
DNA polymerase Pwo (Roche) was used according to manufacturer's instructions, however, with an end concentration of 0.6 μM of both primers and using 50 ngr wt Ad35 DNA as template. Amplification was done as follows: two minutes at 94° C., 30 cycles of 30 seconds at 94° C., 30 seconds at 65° C. and one minute 45 seconds at 72° C., followed by eight minutes at 68° C. To enable cloning in the TA cloning vector PCR2.1, a last incubation with 1 unit superTaq polymerase (HT Biotechnology LTD) for ten minutes at 72° C. was performed.
The 3370 bp amplified fragment contains Ad35 sequences from bp 3401 to 6772 with a NotI site added to the 5′ end. Fragments were purified using the PCR purification kit (LTI).
A second PCR fragment (NdeI-rITR) was generated using the following primers:
35F7:
(SEQ ID NO:55)
5′-GAA TGC TGG CTT CAG TTG TAA TC-3′
and
35R8:
(SEQ ID NO:56)
5′-CGG AAT TCG CGG CCG CAT TTA AAT CAT CAT CAA TAA
TAT ACC-3′.
Amplification was done with pfx DNA polymerase (LTI) according to manufacturer's instructions but with 0.6 μM of both primers and 3% DMSO using 10 ngr. of wtAd35 DNA as template. The program was as follows: three minutes at 94° C. and five cycles of 30 seconds at 94° C., 45 seconds at 40° C., two minutes 45 seconds at 68° C., followed by 25 cycles of 30 seconds at 94° C., 30 seconds at 60° C., two minutes 45 seconds at 68° C. To enable cloning in the TA-cloning vector PCR2.1, a last incubation with 1 unit superTaq polymerase for ten minutes at 72° C. was performed. The 1.6 kb amplified fragment ranging from nucleotides 33178 to the end of the right ITR of Ad35, was purified using the PCR purification kit (LTI).
Both purified PCR fragments were ligated into the PCR2.1 vector of the TA-cloning kit (Invitrogen) and transformed into STBL-2 competent cells (LTI). Clones containing the expected insert were sequenced to confirm correct amplification. Next, both fragments were excised from the vector by digestion with NotI and NdeI and purified from gel using the GENECLEAN kit (BIO 101, Inc.). Cosmid vector pWE15 (Clontech) was digested with NotI, dephosphorylated and also purified from gel. These three fragments were ligated and transformed into STBL2 competent cells (LTI). One of the correct clones that contained both PCR fragments was then digested with NdeI, and the linear fragment was purified from gel using the GENECLEAN kit. Ad35 wt DNA was digested with NdeI and the 26.6 kb fragment was purified from LMP gel using agarase enzyme (Roche) according to the manufacturer's instructions. These fragments were ligated together and packaged using λ phage packaging extracts (Stratagene) according to the manufacturer's protocol. After infection into STBL-2 cells, colonies were grown on plates and analyzed for presence of the complete insert. One clone with the large fragment inserted in the correct orientation and having the correct restriction patterns after independent digestions with three enzymes (NcoI, PvuII and ScaI) was selected. This clone is designated pWE.Ad35.pIX-rITR. It contains the Ad35 sequences from bp 3401 to the end and is flanked by NotI sites ( FIG. 14 ).
Generation of Ad35 Based Recombinant Viruses on PER.C6
Wild-type Ad35 virus can be grown on PER.C6 packaging cells to very high titers. However, whether the Ad5-E1 region that is present in PER.C6 is able to complement E1-deleted Ad35 recombinant viruses is unknown. To test this, PER.C6 cells were cotransfected with the above described adapter plasmid pAdApt35.LacZ and the large backbone fragment pWE.Ad35.pIX-rITR. First, pAdApt35.LacZ was digested with PacI and pWE.Ad35.pIX-rITR was digested with NotI. Without further purification, 4 μgr of each construct was mixed with DMEM (LTI) and transfected into PER.C6 cells, seeded at a density of 5×10 6 cells in a T25 flask the day before, using Lipofectamin (LTI) according to the manufacturer's instructions. As a positive control, 6 μgr of PacI-digested pWE.Ad35.pIX-rITR DNA was cotransfected with a 6.7 kb NheI fragment isolated from Ad35 wt DNA containing the left end of the viral genome including the E1 region. The next day, medium (DMEM with 10% FBS and 10 mM MgCl 2 ) was refreshed and cells were further incubated. At day 2 following the transfection, cells were trypsinized and transferred to T80 flasks. The positive control flask showed CPE at five days following transfection, showing that the pWE.Ad35.pIX-rITR construct is functional at least in the presence of Ad35-E1 proteins. The transfection with the Ad35 LacZ adapter plasmid and pWE.Ad35.pIX-rITR did not give rise to CPE. These cells were harvested in the medium at day 10 and freeze/thawed once to release virus from the cells. 4 ml of the harvested material was added to a T80 flask with PER.C6 cells (at 80% confluency) and incubated for another five days. This harvest/re-infection was repeated for two times but there was no evidence for virus-associated CPE.
From this experiment, it seems that the Ad5-E1 proteins are not, or not well enough, capable of complementing Ad35 recombinant viruses, however, it may be that the sequence overlap of the adapter plasmid and the pWE.Ad35.pIX-rITR backbone plasmid is not large enough to efficiently recombine and give rise to a recombinant virus genome. The positive control transfection was done with a 6.7 kb left end fragment and therefore the sequence overlap was about 3.5 kb. The adapter plasmid and the pWE.Ad35.pIX-rITR fragment have a sequence overlap of 1.3 kb. To check whether the sequence overlap of 1.3 kb is too small for efficient homologous recombination, a cotransfection was done with PacI-digested pWE.Ad35.pIX-rITR and a PCR fragment of Ad35 wt DNA generated with the above mentioned 35F1 and 35R4 using the same procedures as previously described herein. The PCR fragment thus contains left end sequences up to bp 4669 and, therefore, has the same overlap sequences with pWE.Ad35.pIX-rITR as the adapter plasmid pAdApt35.LacZ, but has Ad35 E1 sequences. Following PCR column purification, the DNA was digested with SalI to remove possible intact template sequences. A transfection with the digested PCR product alone served as a negative control. Four days after the transfection, CPE occurred in the cells transfected with the PCR product and the Ad35 pIX-rITR fragment, and not in the negative control. This result shows that a 1.3 kb overlapping sequence is sufficient to generate viruses in the presence of Ad35 E1 proteins. From these experiments, we conclude that the presence of at least one of the Ad35.E1 proteins is necessary to generate recombinant Ad35-based vectors from plasmid DNA on Ad5-complementing cell lines.
Example 8
Construction of Ad35.E1 Expression Plasmids
Since Ad5-E1 proteins in PER.C6 are incapable of complementing Ad35 recombinant viruses efficiently, Ad35 μl proteins have to be expressed in Ad5-complementing cells (e.g., PER.C6). Otherwise, a new packaging cell line expressing Ad35 E1 proteins has to be made, starting from either diploid primary human cells or established cell lines not expressing adenovirus E1 proteins. To address the first possibility, the Ad35 E1 region was cloned in expression plasmids as described below.
First, the Ad35 E1 region from bp 468 to bp 3400 was amplified from wtAd35 DNA using the following primer set: 35F11: 5′-GGG GTA CCG AAT TCT CGC TAG GGT ATT TAT ACC-3′ (SEQ ID NO:57) and 35F10: 5′-GCT CTA GAC CTG CAG GTT AGT CAG TTT CTT CTC CAC TG-3′ (SEQ ID NO:58). This PCR introduces a KpnI and EcoRI site at the 5′ end and an SbfI and XbaI site at the 3′ end.
Amplification on 5 ngr. template DNA was done with Pwo DNA polymerase (Roche) using the manufacturer's instructions, however, with both primers at a final concentration of 0.6 μM. The program was as follows: two minutes at 94° C., five cycles of 30 seconds at 94° C., 30 seconds at 56° C. and two minutes at 72° C., followed by 25 cycles of 30 seconds at 94° C., 30 seconds at 60° C. and two minutes at 72° C., followed by ten minutes at 72° C. PCR product was purified by a PCR purification kit (LTI) and digested with KpnI and XbaI. The digested PCR fragment was then ligated to the expression vector pRSVhbvNeo (see below) also digested with KpnI and XbaI. Ligations were transformed into competent STBL-2 cells (LTI) according to manufacturer's instructions and colonies were analyZed for the correct insertion of Ad35E1 sequences into the polylinker in between the RSV promoter and HBV polyA.
The resulting clone was designated pRSV.Ad35-E1 ( FIG. 15 ). The Ad35 sequences in pRSV.Ad35-E1 were checked by sequence analysis.
pRSVhbvNeo was generated as follows: pRc-RSV (Invitrogen) was digested with PvuII, dephosphorylated with TSAP enzyme (LTI), and the 3 kb vector fragment was isolated in low melting point agarose (LMP). Plasmid pPGKneopA ( FIG. 16 ; described in International Patent Application WO96/35798) was digested with SspI completely to linearize the plasmid and facilitate partial digestion with PvuII. Following the partial digestion with PvuII, the resulting fragments were separated on a LMP agarose gel and the 2245 bp PvuII fragment, containing the PGK promoter, neomycin-resistance gene and HBVpolyA, was isolated. Both isolated fragments were ligated to give the expression vector pRSV-pNeo that now has the original SV40prom-neo-SV40polyA expression cassette replaced by a PGKprom-neo-HBVpolyA cassette ( FIG. 17 ). This plasmid was further modified to replace the BGHpA with the HBVpA as follows: pRSVpNeo was linearized with ScaI and further digested with XbaI. The 1145 bp fragment, containing part of the Amp gene and the RSV promoter sequences and polylinker sequence, was isolated from gel using the GeneClean kit (Bio Inc. 101). Next, pRSVpNeo was linearized with ScaI and further digested with EcoRI partially and the 3704 bp fragment containing the PGKneo cassette and the vector sequences were isolated from gel as above. A third fragment, containing the HBV polyA sequence flanked by XbaI and EcoRI at the 5′ and 3′ end respectively, was then generated by PCR amplification on pRSVpNeo using the following primer set: HBV-F: 5′-GGC TCT AGA GAT CCT TCG CGG GAC GTC-3′ (SEQ ID NO:59) and HBV-R: 5′-GGC GAA TTC ACT GCC TTC CAC CAA GC-3′ (SEQ ID NO:60).
Amplification was done with Elongase enzyme (LTI) according to the manufacturer's instructions with the following conditions: 30 seconds at 94° C., then fove cycles of 45 seconds at 94° C., one minute at 42° C. and one minute 68° C., followed by 30 cycles of 45 seconds at 94° C., one minute at 65° C. and one minute at 68° C., followed by ten minutes at 68° C. The 625 bp PCR fragment was then purified using the Qiaquick PCR purification kit, digested with EcoRI and XbaI and purified from gel using the GENECLEAN kit. The three isolated fragments were ligated and transformed into DH5α competent cells (LTI) to give the construct pRSVhbvNeo ( FIG. 18 ). In this construct, the transcription regulatory regions of the RSV expression cassette and the neomycin selection marker are modified to reduce overlap with adenoviral vectors that often contain CMV and SV40 transcription regulatory sequences.
Generation of Ad35 Recombinant Viruses on PER.C6 Cells Cotransfected with an Ad35-E1 Expression Construct
PER.C6 cells were seeded at a density of 5×10 6 cells in a T25 flask and, the next day, transfected with a DNA mixture containing:
1 μg pAdApt35.LacZ digested with PacI
5 μg pRSV.Ad35E1 undigested
2 μg pWE.Ad35.pIX-rITR digested with NotI
Transfection was done using Lipofectamine according to the manufacturer's instructions. Five hours after addition of the transfection mixture to the cells, medium was removed and replaced by fresh medium. After two days, cells were transferred to T80 flasks and further cultured. One week post-transfection, 1 ml of the medium was added to A549 cells and, the following day, cells were stained for LacZ expression. Blue cells were clearly visible after two hours of staining indicating that recombinant LacZ expressing viruses were produced. The cells were further cultured, but no clear appearance of CPE was noted. However, after 12 days, clumps of cells appeared in the monolayer and 18 days following transfection, cells were detached. Cells and medium were then harvested, freeze-thawed once, and 1 ml of the crude lysate was used to infect PER.C6 cells in a 6-well plate. Two days after infection, cells were stained for LacZ activity. After two hours, 15% of the cells were stained blue. To test for the presence of wt and/or replicating competent viruses, A549 cells were infected with these viruses and further cultured. No signs of CPE were found indicating the absence of replication competent viruses. These experiments show that recombinant AdApt35.LacZ viruses were made on PER.C6 cells cotransfected with an Ad35-E1 expression construct.
Ad35 recombinant viruses escape neutralization in human serum containing neutralizing activity to Ad5 viruses.
The AdApt35.LacZ viruses were then used to investigate infection in the presence of serum that contains neutralizing activity to Ad5 viruses. Purified Ad5-based LacZ virus served as a positive control for NA. Hereto, PER.C6 cells were seeded in a 24-well plate at a density of 2×10 5 cells/well. The next day, a human serum sample with high neutralizing activity to Ad5 was diluted in culture medium in five steps of five times dilutions. 0.5 ml of diluted serum was then mixed with 4×10 6 virus particles AdApt5.LacZ virus in 0.5 ml medium and, after 30 minutes of incubation at 37° C., 0.5 ml of the mixture was added to PER.C6 cells in duplicate. For the AdApt35.LacZ viruses, 0.5 ml of the diluted serum samples were mixed with 0.5 ml crude lysate containing AdApt35.LacZ virus and, after incubation, 0.5 ml of this mixture was added to PER.C6 cells in duplo. Virus samples incubated in medium without serum were used as positive controls for infection. After two hours of infection at 37° C., medium was added to reach a final volume of 1 ml and cells were further incubated. Two days after infection, cells were stained for LacZ activity. The results are shown in Table II. From these results, it is clear that whereas AdApt5.LacZ viruses are efficiently neutralized, AdApt35.LacZ viruses remain infectious irrespective of the presence of human serum. This proves that recombinant Ad35-based viruses escape neutralization in human sera that contain NA to Ad5-based viruses.
Example 9
An Ad5/fiber35 Chimeric Vector with Cell Type Specificity for Hemopoietic CD34 + Lin − Stem Cells
In Example 3, we described the generation of a library of Ad5 based adenoviruses harboring fiber proteins of other serotypes. As a non-limiting example for the use of this library, we here describe the identification of fiber-modified adenoviruses that show improved infection of hemopoietic stem cells.
Cells isolated from human bone marrow, umbilical cord blood, or mobilized peripheral blood carrying the flow cytometric phenotype of being positive for the CD34 antigen and negative for the early differentiation markers CD33, CD38, and CD71 (lin − ) are commonly referred to as hemopoietic stem cells (HSC). Genetic modification of these cells is of major interest since all hemopoietic lineages are derived from these cells and therefore the HSC is a target cell for the treatment of many acquired or congenital human hemopoietic disorders. Examples of diseases that are possibly amenable for genetic modification of HSC include, but are not limited to, Hurlers disease, Hunter's disease, Sanfilippos disease, Morquios disease, Gaucher disease, Farbers disease, Niemann-Pick disease, Krabbe disease, Metachromatic Leucodistrophy, I-cell disease, severe immunodeficiency syndrome, Jak-3 deficiency, Fucosidose deficiency, thallasemia, and erythropoietic porphyria. Besides these hemopoietic disorders, also strategies to prevent or treat acquired immunodeficiency syndrome (“AIDS”) and hemopoietic cancers are based on the genetic modification of HSCs (or cells derived from HSCs such as CD4 positive T lymphocytes in case of AIDS). The examples listed herein thus aim at introducing DNA into the HSC in order to complement on a genetic level for a gene and protein deficiency. In case of strategies for AIDS or cancer, the DNA to be introduced into the HSC can be anti-viral genes or suicide genes.
Besides the examples listed herein, several other areas exist in which efficient transduction of HSCs using adenoviral vectors can play an important role, for instance, in the field of tissue engineering. In this area, it is important to drive differentiation of HSCs to specific lineages. Some, non-limiting, examples are ex vivo bone formation, cartilage formation, skin formation, as well as the generation of T-cell precursors or endothelial cell precursors. The generation of bone, cartilage or skin in bioreactors can be used for transplantation after bone fractures or spinal cord lesions or severe burn injuries. Naturally, transduced cells can also directly be re-infused into a patient. The formation of large numbers of endothelial cell precursor from HSCs is of interest since these endothelial precursor cells can home, after re-infusion, to sites of cardiovascular injury such as ischemia. Likewise, the formation of large numbers of T-cells from HSCs is of interest since these T-cell precursors can be primed, ex vivo, to eradicate certain targets in the human body after re-infusion of the primed T-cells. Preferred targets in the human body can be tumors or virus-infected cells.
From the herein described examples, it can be concluded that efficient gene delivery to HSCs is a major interest for the field of gene therapy. Therefore, alteration of the Ad5 host cell range to be able to target HSCs in vitro as well as in vivo is a major interest of the invention. To identify a chimeric adenovirus with preferred infection characteristics for human HSCs, we generated a library of Ad5 based viruses carrying the fiber molecule from alternative adenoviral serotypes (serotypes 8, 9, 13, 16, 17, 32, 35, 45, 40-L, 51). The generation of this fiber-modified library is described in Example 3 hereof. Ad5 was included as a reference. A small panel of this library was tested on human TF-1 (erythroid leukemia, ATCC CRL-2003) whereas all chimeric viruses generated were tested on human primary stroma cells and human HSCs. Human TF-1 cells were routinely maintained in DMEM supplemented with 10% FCS and 50 ng/ml IL-3 (Sandoz, Basel, Switzerland). Human primary fibroblast-like stroma, isolated from a bone marrow aspirate, is routinely maintained in DMEM/10% FCS. Stroma was seeded at a concentration of 1×10 5 cells per well of 24-well plates. 24 hours after seeding cells were exposed for two hours to 1000 virus particles per cell of Ad5, Ad5.Fib16, Ad5.Fib17, Ad5.Fib35, Ad5.Fib40-L, or Ad5.Fib51 all carrying GFP as a marker. After two hours, cells were washed with PBS and reseeded in medium without addition of virus. TF-1 cells were seeded at a concentration of 2×10 5 cells per well of 24-well plates and were also exposed for two hours to 1000 virus particles of the different chimeric adenoviruses. Virus was removed by washing the cells after the two hours exposure. Both cell types were harvested 48 hours after virus exposure and analyzed for GFP expression using a flow cytometer. The results on TF-1 cells, shown in FIG. 19 , demonstrate that chimeric adenoviruses carrying a fiber from serotypes 16, 35, or 51 (all derived from adenovirus subgroup B) have preferred infection characteristics as compared to Ad5 (subgroup C), Ad5.Fib 17 (subgroup D), or Ad5.Fib40-L (subgroup F). Primary human stroma was tested since these cells are commonly used as “feeder” cells to allow proliferation and maintenance of HSCs under ex vivo culture conditions. In contrast to the transduction of TF-1 cells, none of the fiber chimeric adenoviruses were able to efficiently transduce human primary stroma ( FIG. 20 ). Reasonable infection of human fibroblast-like primary stroma was observed only with Ad5 despite the observation that none of the known receptor molecules are expressed on these cells (see, Table III). The absence of infection of human stroma using the chimeric viruses is advantageous since, in a co-culture setting, the chimeric adenovirus will not be absorbed primarily by the stroma “feeder” cells.
To test the transduction capacity of the fiber chimeric viruses, a pool of umbilical cord blood (three individuals) was used for the isolation of stem cells. CD34 + cells were isolated from mononuclear cell preparation using a MACS laboratory separation system (Miltenyi Biotec) using the protocol supplied by the manufacturer. Of the CD34 + cells, 2×10 5 were seeded in a volume of 150 μl DMEM (no serum; Gibco, Gaithersburg, Md.) and 10 μl of chimeric adenovirus (to give a final virus particles/cell ratio of 1000) was added. The chimeric adenoviruses tested were Ad5, Ad5.Fib16, Ad5.Fib35, Ad5Fib17, Ad5.Fib51 all containing GFP as a marker. Cells were incubated for two hours in a humidified atmosphere of 10% CO 2 at 37° D. Thereafter, cells were washed once with 500 μl DMEM and re-suspended in 500 μl of StemPro-34 SF medium (Life Technologies, Grand Island, N.Y.).
Cells were then cultured for five days in 24-well plates (Greiner, Frickenhausen, Germany) on irradiated (20 Gy) pre-established human bone marrow stroma (ref 1), in a humidified atmosphere of 10% CO 2 at 37° C. After five days, the entire cell population was collected by trypsinization with 100 μl 0.25% Trypsin-EDTA (Gibco). The number of cells before and after five days of culture was determined using a hematocytometer. The number of CD34 + and CD34 ++ CD33,38,71 − cells in each sample was calculated from the total number of cells recovered and the frequency of the CD34 ++ CD33,38,71 − cells in the whole population as determined by FACS analysis. The transduction efficiency was determined by FACS analysis while monitoring, in distinct sub-populations, the frequency of GFP expressing cells as well as the intensity of GFP per individual cell. The results of this experiment, shown in FIG. 21 , demonstrate that Ad5 or the chimeric adenovirus Ad5.Fib17 does not infect CD34 + Lin − cells as witnessed by the absence of GFP expression. In contrast, with the chimeric viruses carrying the fiber molecule of serotypes 16, 51, or 35 high percentages of GFP positive cells are scored in this cell population. Specificity for CD34 + Lin − is demonstrated since little GFP expression is observed in CD34 + cells that are also expressing CD33, CD38, and CD71. Sub-fractioning of the CD34 + Lin − cells ( FIG. 22 ) showed that the percentage of cells positive for GFP declines using Ad5.Fib16, Ad5.Fib35, or Ad5.Fib51 when the cells become more and more positive for the early differentiation markers CD33 (myeloid), CD71 (erythroid), and CD38 (common early differentiation marker). These results thus demonstrate the specificity of the chimeric adenoviruses Ad5.Fib16, Ad5.Fib35, and Ad5.Fib51 for HSCs.
FIG. 23 shows an alignment of the Ad5 fiber with the chimeric B-group fiber proteins derived from Ad16, 35 and 51. By determining the number of cells recovered after the transduction procedure, the toxicity of adenovirus can be determined. The recovery of the amount of CD34+cells as well as the amount of CD34 + Lin − ( FIG. 24 ) demonstrates that a two hour exposure to 1000 adenovirus particles did not have an effect on the number of cells recovered.
Example 10
An Ad5/fiber35 Chimeric Vector with Cell Type Specificity for Dendritic Cells
Dendritic cells are antigen presenting cells (“APC”), specialized to initiate a primary immune response, and able to boost a memory type of immune response. Dependent on their stage of development, DC display different functions: immature DC are very efficient in the uptake and processing of antigens for presentation by Major Histocompatibility Complex (“MHC”) class I and class II molecules, whereas mature DC, being less effective in antigen capture and processing, perform much better at stimulating naive and memory CD4 + and CD8 + T cells, due to the high expression of MHC molecules and co-stimulatory molecules at their cell surface. The immature DCs mature in vivo after uptake of antigen, travel to the T-cell areas in the lymphoid organs, and prime T-cell activation.
Since DCs are the cells responsible for triggering an immune response, there has been a long standing interest in loading DCs with immunostimulatory proteins, peptides, or the genes encoding these proteins, to trigger the immune system. The applications for this strategy are in the field of cancer treatment as well as in the field of vaccination. So far, anti-cancer strategies have focussed primarily on ex vivo loading of DCs with antigen (protein or peptide). These studies have revealed that this procedure resulted in induction of cytotoxic T cell activity. The antigens used to load the cells are generally identified as being tumor specific. Some, non-limiting, examples of such antigens are GP100, mage, or Mart-1 for melanoma.
Besides treatment of cancer, many other potential human diseases are currently being prevented through vaccination. In the vaccination strategy, a “crippled” pathogen is presented to the immune system via the action of the antigen presenting cells, i.e., the immature DCs. Well-known examples of disease prevention via vaccination strategies include Hepatitis A, B, and C, influenza, rabies, yellow fever, and measles. Besides these well-known vaccination programs, research programs for treatment of malaria, ebola, river blindness, HIV and many other diseases are being developed. Many of the identified pathogens are considered too dangerous for the generation of “crippled” pathogen vaccines. This latter thus calls for the isolation and characterization of proteins of each pathogen to which a “full blown” immune response is mounted, thus resulting in complete protection upon challenge with wild-type pathogen.
For the strategy of loading DCs with immunostimulatory proteins or peptides to become therapeutically feasible, at least two distinct criteria have to be met. First, the isolation of large numbers of DCs that can be isolated, manipulated, and re-infused into a patient, making the procedure autologous. To date, it is possible to obtain such large quantities of immature DCs from cultured peripheral blood monocytes from any given donor. Second, a vector that can transduce DCs efficiently such that the DNA encoding for an immunostimulatory protein can be delivered. The latter is extremely important since it has become clear that the time required for DCs to travel to the lymphoid organs is such that most proteins or peptides are already released from the DCs, resulting in incomplete immune priming. Because DCs are terminally differentiated and thus non-dividing cells, recombinant adenoviral vectors are being considered for delivering the DNA encoding for antigens to DCs. Ideally, this adenovirus should have a high affinity for dendritic cells, but should also not be recognized by neutralizing antibodies of the host such that in vivo transduction of DCs can be accomplished. The latter would obviate the need for ex vivo manipulations of DCs but would result in a medical procedure identical to the vaccination programs that are currently in place, i.e., intramuscular or subcutaneous injection predominantly. Thus, DC transduced by adenoviral vectors encoding an immunogenic protein may be ideally suited to serve as natural adjuvants for immunotherapy and vaccination.
From the described examples, it can be concluded that efficient gene delivery to DCs is a major interest in the field of gene therapy. Therefore, alteration of the Ad5 host cell range to be able to target DCs in vitro as well as in vivo is a major interest of the invention. To identify a chimeric adenovirus with preferred infection characteristics for human DCs, we generated a library of Ad5-based viruses carrying the fiber molecule from alternative serotypes (serotypes 8, 9, 13, 16, 17, 32, 35, 45, 40-L, 51). Ad5 was included as a reference.
We evaluated the susceptibility of human monocyte derived immature and mature DC to recombinant chimeric adenoviruses expressing different fibers.
Human PBMC from healthy donors were isolated through Ficoll-Hypaque density centrifugation. Monocytes were isolated from PBMC by enrichment for CD14 + cells using staining with FITC labelled anti-human CD 14 monoclonal antibody (Becton Dickinson), anti-FITC microbeads and MACS separation columns (Miltenyi Biotec).
This procedure usually results in a population of cells that are <90% CD14 + as analyzed by FACS. Cells were placed in culture using RPMI-1640 medium (Gibco) containing 10% Foetal Bovine Serum (“FBS”) (Gibco), 200 ng/ml rhu GM-CSF (R&D/ITK diagnostics, 100 ng/ml rhu IL-4 (R&D/ITK diagnostics) and cultured for seven days with feeding of the cultures with fresh medium containing cytokines on alternate days. After seven days, the immature DC resulting from this procedure express a phenotype CD83 − ,CD14 low or CD14 − ,HLA-DR + , as was demonstrated by FACS analysis. Immature DCs are matured by culturing the cells in a medium containing 100 ng/ml TNF-a for three days, after which, they expressed CD83 on their cell surface.
In a pilot experiment, 5×10 5 immature DCs were seeded in wells of 24-well plates and exposed for 24 hours to 100 and 1000 virus particles per cell of each fiber recombinant virus. Virus tested was Ad5, and the fiber chimeric viruses based on Ad5: Ad5.Fib12, Ad5.Fib16, Ad5.Fib28, Ad5.Fib32, Ad5.Fib40-L (long fiber of serotype 40), Ad5.Fib49, and Ad5.Fib51 (where Fibxx stands for the serotype from which the fiber molecule is derived). These viruses are derived from subgroup C, A, B, D, D, F, D, and B respectively. After 24 hours, cells were lysed (1% Triton X-100/PBS) and luciferase activity was determined using a protocol supplied by the manufacturer (Promega, Madison, Wis., USA). The results of this experiment, shown in FIG. 25 , demonstrate that Ad5 poorly infects immature DCs as witnessed by the low level of transgene expression. In contrast, Ad5.Fib 16 and Ad5.Fib51 (both a B-group fiber chimeric virus) and also Ad5.Fib40-L (Subgroup F) show efficient infection of immature DCs based on luciferase transgene expression.
In a second experiment, 5×10 5 immature and mature DC were infected with 10,000 virus particles per cell of Ad5, Ad5.Fib16, Ad5.Fib40-L, and Ad5.Fib51 all carrying the LacZ gene as a marker. LacZ expression was monitored by flow cytometric analysis using a CM-FDG kit system and the instructions supplied by the manufacturer (Molecular Probes, Leiden, NL). The results of this experiment, shown in FIG. 26 , correlate with the previous experiment in that Ad5.Fib16 and Ad5.Fib51 are superior to Ad5 in transducing mature and immature human DCs. Also, this experiment shows that Ad5.Fib40-L is not as good as Ad5.Fib16 and Ad5.Fib51, but is better than Ad5.
Based on these results, we tested other chimeric adenoviruses containing fibers of B group viruses, for example, Ad5.Fib11 and Ad5.Fib35 for their capacity to infect DCs. We focussed on immature DCs, since these are the cells that process an expressed transgene product into MHC class I and II presentable peptides. Immature DCs were seeded at a cell density of 5×10 5 cells/well in 24-well plates (Costar) and infected with 1,000 and 5,000 virus particles per cell, after which the cells were cultured for 48 hours under conditions for immature DCs prior to cell lysis and Luciferase activity measurements. The results of this experiment, shown in FIG. 27 , demonstrate that Ad5 based chimeric adenoviruses containing fibers of group-B viruses efficiently infect immature DCs. In a fourth experiment, we again infected immature DCs identically as described in the former experiments but this time Ad5, Ad5.Fib16, and Ad5.Fib35 were used carrying GFP as a marker gene. The results on GFP expression measured with a flow cytometer 48 hours after virus exposure is shown in FIG. 28 , and correlates with the data obtained so far. Thus, the results so far are consistent in that Ad5-based vectors carrying a fiber from an alternative adenovirus derived from subgroup B, predominantly fiber of 35, 51, 16, and 11, are superior to Ad5 for transducing human DCs.
The adenoviruses disclosed herein are also very suitable for vaccinating animals. To illustrate this, we tested DCs derived from mice and chimpanzees to identify whether these viruses could be used in these animal models. The latter, in particular, since the receptor for human adenovirus derived from subgroup B is unknown to date and therefore it is unknown whether this protein is conserved among species. For both species, immature DCs were seeded at a density of 10 5 cells per well of 24-well plates. Cells were subsequently exposed for 48 hours to 1000 virus particles per cell of Ad5, Ad5Fib16, and Ad5.Fib51 in case of mouse DC and Ad5, and Ad.Fib35 in case of chimpanzee DCs (see, FIG. 29 ). The mouse experiment was performed with viruses carrying luciferase as a marker, and demonstrated approximately 10 to 50-fold increased luciferase activity as compared to Ad5.
The chimpanzee DCs were infected with the GFP viruses, and were analyzed using a flow cytometer. These results (also shown in FIG. 29 ) demonstrate that Ad5 (3%) transduces chimpanzee DCs very poorly as compared to Ad5.Fib35 (66.5%).
Example 11
Construction of a Plasmid-Based Vector System to Generate Ad11-based Recombinant Viruses
The results of the neutralization experiments described in Example 5 show that Ad11, like Ad35, was also not neutralized in the vast majority of human serum samples. Therefore, recombinant adenoviruses based on Ad11 are preferred above the commonly used Ad2 and Ad5-based vectors as vectors for gene therapy treatment and vaccination. Both Ad35 and Ad11 are B-group viruses and are classified as viruses belonging to DNA homology cluster 2 (Wadell, 1984). Therefore, the genomes of Ad35 and Ad11 are very similar.
To generate a plasmid-based system for the production of Ad11-based recombinant viruses; the adapter plasmid pAdApt35IP1 generated in Example 7 is modified as follows. Construct pAdApt35IP1 is digested with AvrII and then partially with PacI. The digestion mixture is separated on gel, and the 4.4 kb fragment containing the expression cassette and the vector backbone is isolated using the GENECLEAN kit (BIO 101, Inc.). Then a PCR amplification is performed on wtAd11 DNA using the primers 35F1 and 35R2 (see, Example 7) using Pwo DNA polymerase according to the manufacturer's instructions. The obtained PCR fragment of 0.5 kb is purified using the PCR purification kit (LTI), and ligated to the previously prepared fragment of pAdApt35IP1. This gives construct pAdApt11-35IP1, in which the 5′ adenovirus fragment is exchanged for the corresponding sequence of Ad11. Next, pAdApt11-35IP1 is digested with BglII and partially with PacI. The obtained fragments are separated on gel, and the 3.6 kb fragment containing the vector sequences, the 5′ adenovirus fragment, and the expression cassette is purified from gel as previously described. Next, a PCR fragment is generated using primers 35F3 and 35R4 (see, Example 7) on wtAd11 DNA. Amplification is done as above and the obtained 1.3 kb fragment is purified and digested with BglII and PacI. The isolated fragments are then ligated to give construct pAdApt11IP1. This adapter plasmid now contains Ad11 sequences instead of Ad35 sequences. Correct amplification of PCR amplified Ad11 sequences is verified by comparison of the sequence in this clone with the corresponding sequence of Ad11 DNA. The latter is obtained by direct sequencing on Ad11 DNA using the indicated PCR primers. The large cosmid clone containing the Ad11 backbone is generated as follows. First, a PCR fragment is amplified on Ad11 DNA using the primers 35F5 and 35R6 with Pwo DNA polymerase as described in Example 7 for Ad35 DNA. The PCR fragment is then purified using the PCR purification kit (LTI) and digested with NotI and NdeI. The resulting 3.1 kb fragment is isolated from gel using the GENECLEAN kit (Bio 101, Inc.). A second PCR fragment is then generated on Ad11 DNA using the primers 35F7 and 35R8 (see, Example 7) with Pwo DNA polymerase according to the manufacturer's instructions and purified using the PCR purification kit (LTI). This amplified fragment is also digested with NdeI and NotI and the resulting 1.6 kb fragment is purified from gel as previously described. The two digested PCR fragments are then ligated together with cosmid vector pWE15 previously digested with NotI and dephosphorylated using Tsap enzyme (LTI) according to manufacturer's instructions. One clone is selected that has one copy of both fragments inserted. Correct clones are selected by analytical NotI digestion that gives a fragment of 4.7 kb. Confirmation is obtained by a PCR reaction using primers 35F5 and 35R8 that gives a fragment of the same size. The correct clone is then linearized with NdeI and isolated from gel. Next, wtAd11 DNA is digested with NdeI and the large 27 kb fragment is isolated from low melting point agarose gel using agarase enzyme (Roche) according to the manufacturer's instructions. Both fragments are then ligated and packaged using λ phage packaging extracts (Stratagene) according to the manufacturer's protocol. After infection into STBL-2 cells (LTI), colonies are grown on plates, and analyzed for the presence of the complete insert. The functionality of selected clones is then tested by cotransfection on PER.C6. Hereto, the DNA is digested with NotI and 6 μgr is cotransfected with 2 μgr of a PCR fragment generated on Ad11 DNA with primers 35F1 and 35R4 (see, Example 7). Correct clones give CPE within one week following transfection. The correct clone is designated pWE.Ad11.pIX-rITR.
Using the previously described procedure, a plasmid-based system consisting of an adapter plasmid suitable for insertion of foreign genes and a large helper fragment containing the viral backbone is generated. Recombinant Ad11-based viruses are made using the methods described herein for Ad35-based recombinant viruses.
Example 12
Neutralization of Adenoviruses in Samples Derived from Patients
In the neutralization experiments described in Examples 1 and 5, all samples were derived from healthy volunteers. Since one of the applications of non-neutralized vectors is in the field of gene therapy, it is interesting to investigate whether Ad35 is also neutralized with a low frequency and with low titers in groups of patients that are candidates for treatment with gene therapy.
Cardio-Vascular Disease Patients
26 paired serum and pericardial fluid (PF) samples were obtained from patients with heart failure. These were tested against Ad5 and Ad35 using the neutralization assay described in Example 1. The results confirmed the previous data with samples from healthy volunteers. 70% of the serum samples contained NA to Ad5 and 4% to Ad35. In the pericardial fluid samples the titers were lower resulting in a total of 40% with NA to Ad5 and none to Ad35. There was a good correlation between NA in PF and serum, i.e., there were no positive PF samples without NA in the paired serum sample. These results show that non-neutralized vectors based on Ad35 are preferred over Ad5 vectors for treatment of cardio-vascular diseases. As is true for all forms of non-neutralized vectors in this application, the vector may be based on the genome of the non-neutralized serotype or may be based on Ad5 (or another serotype) though displaying at least the major capsid proteins (hexon, penton and optionally fiber) of the non-neutralized serotype.
Rheumatoid Arthritis Patient
The molecular determinant underlying arthritis is presently not known, but both T-cell dysfunction and imbalanced growth factor production in joints is known to cause inflammation and hyperplasia of synovial tissue. The synoviocytes start to proliferate and invade the cartilage and bone that leads to destruction of these tissues. Current treatment starts (when in an early stage) with administration of anti-inflammatory drugs (anti-TNF, IL-RA, IL-10) and/or conventional drugs (e.g., MTX, sulfasalazine). In late stage RA, synovectomy is performed which is based on surgery, radiation, or chemical intervention. An alternative or additional option is treatment via gene therapy where an adenoviral vector is delivered directly into the joints of patients and expresses an anti-inflammatory drug or a suicide gene. Previous studies performed in rhesus monkeys suffering from collagen-induced arthritis have shown that Ad5-based vectors carrying a marker gene can transduce synoviocytes. Whether in the human situation adenoviral delivery is hampered by the presence of NA is not known. To investigate the presence of NA in the synovial fluid (“SF”) of RA patients, SF samples were obtained from a panel of 53 randomly selected patients suffering from RA. These were tested against several wt adenoviruses using the neutralization assay described in Example 1. Results of this screen are presented in Table III. Adenovirus type 5 was found to be neutralized in 72% of the SF samples. Most of these samples contain high titers of NA since the highest dilution of the SF sample that was tested (64×) neutralized Ad5 viruses. This means that adenoviral vector delivery to the synoviocytes in the joints of RA patients will be very inefficient. Moreover, since the titers in the SF are so high it is doubtful whether lavage of the joints prior to vector injection will remove enough of the NA. Of the other serotypes that were tested, Ad35 was shown to be neutralized in only 4% of the samples. Therefore, these data confirm the results obtained in serum samples from healthy patients and show that, for treatment of RA, Ad35-based vectors or chimeric vectors displaying at least some of the capsid proteins from Ad35 are preferred vectors.
Example 13
Modifications in the Backbone of Ad35-based Viruses
Generation of pBr/Ad35.Pac-rITR and pBr/Ad35.PRn
Example 4 describes the generation of the Ad35 subclone pBr/Ad35.Eco13.3. This clone contains Ad35 sequences from bp 21943 to the end of the right ITR cloned into the EcoRI and EcoRV sites of pBr322. To extend these sequences to the PacI site located at bp 18137 in Ad35, pBr/Ad35.Eco13.3 (see, Example 4) was digested with AatII and SnaBI and the large vector-containing fragment was isolated from gel using the QIAEX II gel extraction kit (Qiagen). Ad35 wt DNA was digested with PacI and SnaBI and the 4.6 kb fragment was isolated as above. This fragment was then ligated to a double-stranded (“ds”) linker containing a PacI and an AatII overhang. This linker was obtained after annealing the following oligonucleotides: A-P1: 5′-CTG GTG GTT AAT-3′ (SEQ ID NO:61) and A-P2: 5′-TAA CCA CCA GAC GT-3′ (SEQ ID NO:62).
The ligation mix containing the double stranded linker and the PacI-SnaBI Ad35 fragment was separated from unligated linker on a LMP gel. The 4.6 kb band was cut out of the gel, molten at 65° C., and then ligated to the purified pBr/Ad35.Eco13.3 vector fragment digested with AatII and SnaBI. Ligations were transformed into electrocompetent DH10B cells (Life Technologies Inc.). The resulting clone, pBr/Ad35.Pac-rITR, contained Ad35 sequences from the PacI site at bp 18137 up to the right ITR.
Next, a unique restriction site was introduced at the 3′ end of the right ITR to be able to free the ITR from vector sequences. Hereto, a PCR fragment was used that covers Ad35 sequences from the NdeI site at bp 33165 to the right ITR having the restriction sites SwaI, NotI and EcoRI attached to the rITR. The PCR fragment was generated using primers 35F7 and 35R8 (described in Example 7). After purification, the PCR fragment was cloned into the AT cloning vector (Invitrogen) and sequenced to verify correct amplification. The correct amplified clone was then digested with EcoRI, blunted with Klenow enzyme and subsequently digested with NdeI and the PCR fragment was isolated. In parallel, the NdeI in the pBr vector in pBr/Ad35.Pac-rITR was removed as follows: A pBr322 vector from which the NdeI site was removed by digestion with NdeI, Klenow treatment and religation, was digested with AatII and NheI. The vector fragment was isolated in LMP gel and ligated to the 16.7 kb Ad35 AatII-NheI fragment from pBr/Ad35.Pac-rITR that was also isolated in an LMP gel. This generated pBr/Ad35.Pac-rITR.ΔNdeI. Next, pBr/Ad35.Pac-rITR.ΔNdeI was digested with NheI, the ends were filled in using Kienow enzyme, and the DNA was then digested with NdeI. The large fragment containing the vector and Ad35 sequences was isolated. Ligation of this vector fragment and the PCR fragment resulted in pBr/Ad35.PRn. In this clone, specific sequences coding for fiber, E2A, E3, E4 or hexon can be manipulated. In addition, promoter sequences that drive, for instance, the E4 proteins or the E2 can be mutated or deleted and exchanged for heterologous promoters.
2) Generation of Ad35-Based Viruses with Fiber Proteins from Different Serotypes
Adenoviruses infect human cells with different efficiencies. Infection is accomplished by a two-step process involving both the fiber proteins that mediate binding of the virus to specific receptors on the cells, and the penton proteins that mediate internalization by interaction of, for example, the RGD sequence to integrins present on the cell surface. For subgroup B viruses, of which Ad35 is a member, the cellular receptor for the fiber protein is not known. Striking differences exist in infection efficiency of human cells of subgroup B viruses compared to subgroup C viruses like Ad5 (see, International Patent Application WO 00/03029 and European Patent Application EP 99200624.7). Even within one subgroup, infection efficiencies of certain human cells may differ between various serotypes. For example, the fiber of Ad16, when present on an Ad5-based recombinant virus infects primary endothelial cells, smooth muscle cells and synoviocytes of human and rhesus monkey origin better than Ad5 chimeric viruses carrying the fiber of Ad35 or Ad51. Thus, to obtain high infection efficiencies of Ad35-based viruses, it may be necessary to change the fiber protein for a fiber protein of a different serotype. The technology for such fiber chimeras is described for Ad5-based viruses in Example 3, and is below exemplified for Ad35 viruses.
First, most fiber sequences are deleted from the Ad35 backbone in construct pBr/Ad35.PRn as follows:
The left flanking sequences and part of the fiber protein in Ad35 ranging from bp 30225 upstream of a unique MluI site up to bp 30872 (numbers according to wt Ad35 sequence as disclosed in FIG. 6 ) in the tail of fiber are amplified using primers DF35-1: 5′-CAC TCA CCA CCT CCA ATT CC-3′ (SEQ ID NO:63) and DF35-2: 5′-CGG GAT CCC GTA CGG GTA GAC AGG GTT GAA GG-3′ (SEQ ID NO:64).
This PCR amplification introduces a unique BsiWI site in the tail of the fiber gene. The right flanking sequences ranging from the end of the fiber protein at bp 31798 to bp 33199 (numbering according to wtAd35 sequence, FIG. 6 ), 3′ from the unique NdeI site is amplified using primers DF35-3: 5′-CGG GAT CCG CTA GCT GAA ATA AAG TTT AAG TGT TTT TAT TTA AAA TCA C-3′ (SEQ ID NO:65) and DF35-4: 5′-CCA GTT GCA TTG CTT GGT TGG-3′ (SEQ ID NO:66).
This PCR introduces a unique NheI site in the place of the fiber sequences. PCR amplification is done with Pwo DNA polymerase (Roche) according to the manufacturer's instructions. After amplification, the PCR products are purified using a PCR purification kit and the fragments are digested with BamHI and ligated together. The 2 kb ligated fragments are purified from gel, and cloned in the PCR Script Amp vector (Stratagene). Correct amplification is checked by sequencing. The PCR fragment is then excised as an MluI/NdeI fragment and cloned in pBr/Ad35.PRn digested with the same enzymes. This generates pBr/Ad35.PRΔfib, a shuttle vector suitable to introduce fiber sequences of alternative serotypes. This strategy is analogous to the fiber modification strategy for Ad5-based viruses as disclosed in International Patent Application WO00/03029. Primers that are listed in Table I of that application were used to amplify fiber sequences of various subgroups of adenovirus. For amplification of fibers that are cloned in the pBr/Ad35.PRΔfib, the same (degenerate) primer sequences can be used, however, the NdeI site in the forward primers (tail oligonucleotides A to E) should be changed to a BsiWI site and the NsiI site in the reverse oligo (knob oligonucleotide 1 to 8) should be changed in an NheI site. Thus, fiber 16 sequences are amplified using the following degenerate primers: 5′-CCK GTS TAC CCG TAC GAA GAT GAA AGC-3′ (SEQ ID NO:67) (where K can be a T or G and S can be a C or G as both are degenerate oligo nucleotides) and 5′-CCG GCT AGC TCA GTC ATC TTC TCT GAT ATA-3′ (SEQ ID NO:68). Amplified sequences are then digested with BsiWI and NheI and cloned into pBr/Ad35.PRΔfib digested with the same enzymes to generate pBr/Ad35.PRfib16. The latter construct is then digested with PacI and Swal and the insert is isolated from gel. The PacI/SwaI Ad35 fragment with modified fiber is then cloned into the corresponding sites of pWE/Ad35.pIX-rITR to give pWE/Ad35.pIX-rITR.fib16. This cosmid backbone can then be used with an Ad35-based adapter plasmid to generate Ad35 recombinant viruses that display the fiber of Ad 16. Other fiber sequences can be amplified with (degenerate) primers as mentioned above. If one of the fibers sequences turns out to have an internal BsiWI or NheI site, the PCR fragment has to be digested partially with that enzyme.
Generation of Ad35-Based Viruses with Inducible, E1 Independent, E4 expression
The adenovirus E4 promoter is activated by expression of E1 proteins. It is unknown whether the Ad5 E1 proteins are capable of mediating activation of the Ad35 E4 promoter. Therefore, to enable production of Ad35 recombinant viruses on PER.C6 cells, it may be advantageous to make E4 expression independent of E1. This can be achieved by replacing the Ad35-E4 promoter by heterologous promoter sequences like, but not limited to, the 7xTetO promoter.
Recombinant E1-deleted Ad5-based vectors are shown to have residual expression of viral genes from the vector backbone in target cells, despite the absence of E1 expression. Viral gene expression increases the toxicity and may trigger a host immune response to the infected cell. For most applications of adenoviral vectors in the field of gene therapy and vaccination, it is desired to reduce or diminish the expression of viral genes from the backbone. One way to achieve this is to delete all, or as much as possible, sequences from the viral backbone. By deleting E2A, E2B or E4 genes and/or the late gene functions, one has to complement for these functions during production. This complementation can either be by means of a helper virus or through stable addition of these functions, with or without inducible transcription regulation, to the producer cell. Methods to achieve this have been described for Ad5 and are known in the art. One specific method is replacement of the E4 promoter by promoter sequences that are not active in the target cells. E4 proteins play a role in, for example, replication of adenoviruses through activation of the E2 promoter and in late gene expression through regulation of splicing and nuclear export of late gene transcripts. In addition, at least some of the E4 proteins are toxic to cells. Therefore, reduction or elimination of E4 expression in target cells will further improve Ad35-based vectors. One way to achieve this is to replace the E4 promoter by a heterologous promoter that is inactive in the target cells. An example of a heterologous promoter/activator system that is inactive in target cells is the tetracycline-inducible TetO system (Gossen and Bujard, 1992). Other prokaryotic or synthetic promoter/activator systems may be used. In this example, the E4 promoter in the backbone of the viral vector is replaced by a DNA fragment containing 7 repeats of the tetracycline responsive element from the tet operon (7xTetO). A strong transactivator for this promoter is a fusion protein containing the DNA binding domain of the tet repressor and the activation domain of VP16 (Tet transactivator protein, Tta). Strong E4 expression, independent of E1 expression, can be accomplished in PER.C6 cells expressing Tta. Tta-expressing PER.C6 cells have been generated and described (see, Example 15). Ad5 derived E1-deleted viruses with E4 under control of 7xTetO can be generated and propagated on these cells. Following infection in cells of human or animal origin (that do not express the Tta transactivator), E4 expression was found to be greatly diminished compared to E1 deleted viruses with the normal E4 promoter.
What follows is the construction of pWE/Ad35.pIX-rITR.TetO-E4, a cosmid helper vector to produce viruses with the E4 promoter replacement.
First, a fragment was generated by PCR amplification on pBr/Ad35.PRn DNA using the following primers: 3551TR: 5′-GAT CCG GAG CTC ACA ACG TCA TTT TCC CAC G-3′ (SEQ ID NO:69) and 3531TR: 5′-CGG AAT TCG CGG CCG CAT TTA AAT C-3′ (SEQ ID NO:70).
This fragment contains sequences between bp 34656 (numbering according to wtAd35) and the NotI site 3′ of the right ITR in pBr/Ad35.PRn and introduces an SstI site 5′ of the right ITR sequence.
A second PCR fragment was generated on pBr/Ad35.PRn DNA using primers: 35DE4: 5′-CCC AAG CTT GCT TGT GTA TAT ATA TTG TGG-3′ (SEQ ID NO:71) and 35F7: see, Example 7.
This PCR amplifies Ad35 sequences between bp 33098 and 34500 (numbering according to wtAd35) and introduces a HindIII site upstream of the E4 Tata-box. With these two PCR reactions the right- and left-flanking sequences of the E4 promoter are amplified. For amplification, Pwo DNA polymerase was used according to manufacturer's instructions
A third fragment containing the 7xTetO promoter was isolated from construct pAAO-E-TATA-7xTetO by digestion with SstI and HindIII. The generation of pAAO-E-TATA-7xTetO is described below. The first PCR fragment (355/353) was then digested with SstI and NotI and ligated to the 7xTetO fragment. The ligation mixture was then digested with HindIII and NotI and the 0.5 kb fragment is isolated from gel. The second PCR fragment (35DE4/35F7) was digested with NdeI and HindIII and gel purified. These two fragments were then ligated into pBr/Ad35.PRn digested with NdeI and NotI to give pBr/Ad35.PR.TetOE4. The modification of the E4 promoter was then transferred to the Ad35 helper cosmid clone by exchanging the PacI/Swal fragment of the latter with the one from pBr/Ad35.PR.TetOE4 to give pWE/Ad35.pIX-rITR.TetOE4.
pAAO-E-TATA.7xTetO was generated as follows. Two oligonucleotides were synthesized: TATAplus: 5′-AGC TTT CTT ATA AAT TTT CAG TGT TAG ACT AGT AAA TTG CTT AAG-3′ (SEQ.I.D.NO:72) and TATAmin: 5′-AGC TCT TAA GCA ATT TAC TAG TCT AAC ACT GAA AAT TTA TAA GAA-3′ (SEQ ID NO:73). (The underlined sequences form a modified TATA box).
The oligonucleotides were annealed to yield a double stranded DNA fragment with 5′ overhangs that are compatible with HindIII-digested DNA. The product of the annealing reaction was ligated into HindIII-digested pGL3-Enhancer Vector (Promega) to yield pAAO-E-TATA. The clone that had the HindIII site at the 5′ end of the insert restored was selected for further cloning.
Next, the heptamerized tet-operator sequence was amplified from the plasmid pUHC-13-3 (Gossen and Bujard, 1992) in a PCR reaction using the Expand PCR system (Roche) according to the manufacturer's protocol. The following primers were used: Tet3: 5′-CCG GAG CTC CAT GGC CTA ACT CGA GTT TAC CAC TCC C-3′ (SEQ ID NO:74) and TetS: 5′-CCC AAG CTT AGC TCG ACT TTC ACT TTT CTC-3′ (SEQ ID NO:75).
The amplified fragment was digested with SstI and HindIII (these sites are present in tet3 and tet5, respectively) and cloned into SstI/HindIII-digested pAAO-E-TATA giving rise to pAAO-E-TATA-7xtetO.
To test the functionality of the generated pWE/Ad35.pIX-rITR.TetOE4 cosmid clone, the DNA was digested with NotI. The left end of wtAd35 DNA was then amplified using primers 35F1 and 35R4 (see, Example 7). Following amplification, the PCR mixture was purified and digested with SalI to remove intact viral DNA. Then 4 gr of both the digested pWE/Ad35.pIX-rITR.TetOE4 and the PCR fragment was cotransfected into PER.C6-tTA cells that were seeded in T25 flasks the day before. Transfected cells were transferred to T80 flasks after two days and another two days later CPE was obtained, showing that the cosmid backbone is functional.
Example 14
Generation of Cell Lines Capable of Complementing E1-deleted Ad35 Viruses
Generation of pIG135 and pIG270
Construct pIG.E1A.E1B contains E1 region sequences of Ad5 corresponding to nucleotides 459 to 3510 of the wt Ad5 sequence (Genbank accession number M72360) operatively linked to the human phosphoglycerate kinase promoter (“PGK”) and the Hepatitis B Virus polyA sequences. The generation of this construct is described in International Patent Application No. WO97/00326. The E1 sequences of Ad5 were replaced by corresponding sequences of Ad35 as follows. pRSV.Ad35-E1 (described in Example 8) was digested with EcoRI and Sse8387I and the 3 kb fragment corresponding to the Ad35 E1 sequences was isolated from gel. Construct pIG.E1A.E1B was digested with Sse8387I completely and partially with EcoRI. The 4.2 kb fragment corresponding to vector sequences without the Ad5 E1 region but retaining the PGK promoter were separated from other fragments on LMP agarose gel and the correct band was excised from gel. Both obtained fragments were ligated resulting in pIG.Ad35-E1.
This vector was further modified to remove the LacZ sequences present in the pUC119 vector backbone. Hereto, the vector was digested with BsaAI and BstXI and the large fragment was isolated from gel. A double stranded oligo was prepared by annealing the following two oligos: BB1: 5′-GTG CCT AGG CCA CGG GG-3′ (SEQ ID NO:76) and BB2: 5′-GTG GCC TAG GCA C-3′ (SEQ ID NO:77).
Ligation of the oligo and the vector fragment resulted in construct pIG135. Correct insertion of the oligo restores the BsaAI and BstXI sites and introduces a unique AvrII site. Next, we introduced a unique site at the 3′ end of the Ad35-E1 expression cassette in pIG135. Hereto, the construct was digested with SapI and the 3′ protruding ends were made blunt by treatment with T4 DNA polymerase. The thus treated linear plasmid was further digested with BsrGI and the large vector-containing fragment was isolated from gel. To restore the 3′ end of the HBVpolyA sequence and to introduce a unique site, a PCR fragment was generated using the following primers: 270F: 5′-CAC CTC TGC CTA ATC ATC TC-3′ (SEQ ID NO:78) and 270R: 5′-GCT CTA GAA ATT CCA CTG CCT TCC ACC-3′ (SEQ ID NO:79).
The PCR was performed on pIG.Ad35.E1 DNA using Pwo polymerase (Roche) according to the manufacturer's instructions. The obtained PCR product was digested with BsrGI and dephosphorylated using Tsap enzyme (LTI), the latter to prevent insert dimerization on the BsrGI site. The PCR fragment and the vector fragment were ligated to yield construct pIG270.
Ad35 E1 Sequences are Capable of Transforming Rat Primary Cells
Newborn WAG/RU rats were sacrificed at 1 week of gestation and kidneys were isolated. After careful removal of the capsule, kidneys were disintegrated into a single cell suspension by multiple rounds of incubation in trypsin/EDTA (LTI) at 37° C. and collection of floating cells in cold PBS containing 1% FBS. When most of the kidney was trypsinized, all cells were re-suspended in DMEM supplemented with 10% FBS and filtered through a sterile cheesecloth. Baby Rat Kidney (BRK) cells obtained from one kidney were plated in five dishes (Greiner, 6 cm). When a confluency of 70-80% was reached, the cells were transfected with 1 or 5 μgr DNA/dish using the CaPO 4 precipitation kit (LTI) according to the manufacturer's instructions. The following constructs were used in separate transfections: pIG.E1A.E1B (expressing the Ad5-E1 region), pRSV.Ad35-E1, pIG.Ad35-E1 and pIG270 (the latter expressing the Ad35-E1). Cells were incubated at 37° C., 5% CO 2 until foci of transformed cells appeared. Table IV shows the number of foci that resulted from several transfection experiments using circular or linear DNA. As expected, the Ad5-E1 region efficiently transformed BRK cells. Foci also appeared in the Ad35-E1 transfected cell layer although with lower efficiency. The Ad35 transformed foci appeared at a later time point: ˜2 weeks post transfection compared with seven to ten days for Ad5-E1. These experiments clearly show that the E1 genes of the B group virus Ad35 are capable of transforming primary rodent cells. This proves the functionality of the Ad35-E1 expression constructs and confirms earlier findings of the transforming capacity of the B-group viruses Ad3 and Ad7 (Dijkema, 1979). To test whether the cells in the foci were really transformed a few foci were picked and expanded. From the seven picked foci, at least five turned out to grow as established cell lines.
Generation of New Packaging Cells Derived from Primary Human Amniocytes
Amniotic fluid obtained after amniocentesis was centrifuged and cells were re-suspended in AmnioMax medium (LTI) and cultured in tissue culture flasks at 37° C. and 10% CO 2 . When cells were growing nicely (approximately one cell division/24 hrs.), the medium was replaced with a 1:1 mixture of AmnioMax complete medium and DMEM low glucose medium (LTI) supplemented with Glutamax I (end concentration 4 mM, LTI) and glucose (end concentration 4.5 gr/L, LTI) and 10% FBS (LTI). For transfection ˜5×10 5 cells were plated in 10 cm tissue culture dishes. The day after, cells were transfected with 20 μgr of circular pIG270/dish using the CaPO 4 transfection kit (LTI) according to manufacturer's instructions and cells were incubated overnight with the DNA precipitate. The following day, cells were washed four times with PBS to remove the precipitate and further incubated for over three weeks until foci of transformed cells appeared. Once a week, the medium was replaced by fresh medium. Other transfection agents like, but not limited to, LipofectAmine (LTI) or PEI (Polyethylenimine, high molecular weight, water-free, Aldrich) were used. Of these three agents PEI reached the best transfection efficiency on primary human amniocytes: ˜1% blue cells 48 hours following transfection of pAdApt35.LacZ.
Foci are isolated as follows: The medium is removed and replaced by PBS after which foci are isolated by gently scraping the cells using a 50-200 μl Gilson pipette with a disposable filter tip. Cells contained in ˜10 μl PBS were brought in a 96 well plate containing 15 μl trypsin/EDTA (LTI) and a single cell suspension was obtained by pipetting up and down and a short incubation at room temperature. After addition of 200 μl of the above described 1:1 mixture of AmnioMax complete medium and DMEM with supplements and 10% FBS, cells were further incubated. Clones that continued to grow were expanded and their ability to complement growth of E1-deleted adenoviral vectors of different sub-groups was analyzed, specifically ones derived from B-group viruses, specifically from Ad35 or Ad11.
Generation of New Packaging Cell Lines from HER Cells
HER cells were isolated and cultured in DMEM medium supplemented with 10% FBS (LTI). The day before transfection, ˜5×10 5 cells were plated in 6 cm dishes and cultured overnight at 37° C. and 10% CO 2 . Transfection was done using the CaPO 4 precipitation kit (LTI) according to the manufacturer's instructions. Each dish was transfected with 8-10 μgr pIG270 DNA, either as a circular plasmid or as a purified fragment. To obtain the purified fragment, pIG270 was digested with AvrII and XbaI and the 4 kb fragment corresponding to the Ad35 E1 expression cassette was isolated from gel by agarase treatment (Roche). The following day, the precipitate was washed away carefully by four washes with sterile PBS. Then fresh medium was added and transfected cells were further cultured until foci of transformed cells appear. When large enough (>100 cells) foci were picked and brought into 96-well plates as described above. Clones of transformed HER cells that continue to grow, were expanded and tested for their ability to complement growth of E1-deleted adenoviral vectors of different sub-groups specifically ones derived from B-group viruses specifically from Ad35 or Ad11.
New packaging cell lines derived from PER.C6
As described in Example 8, it is possible to generate and grow Ad35 E1-deleted viruses on PER.C6 cells with cotransfection of an Ad35-E1 expression construct, e.g., pRSV.Ad35.E1. However, large-scale production of recombinant adenoviruses using this method is cumbersome because, for each amplification step, a transfection of the Ad35-E1 construct is needed. In addition, this method increases the risk of non-homologous recombination between the plasmid and the virus genome with high chances of generation of recombinant viruses that incorporate E1 sequences resulting in replication competent viruses. To avoid this, the expression of Ad35-E1 proteins in PER.C6 has to be mediated by integrated copies of the expression plasmid in the genome. Since PER.C6 cells are already transformed and express Ad5-E1 proteins, addition of extra Ad35-E1 expression may be toxic for the cells, however, it is not impossible to stably transfect transformed cells with E1 proteins since Ad5-E1 expressing A549 cells have been generated.
In an attempt to generate recombinant adenoviruses derived from subgroup B virus Ad7, Abrahamsen et al. (1997) were not able to generate E1-deleted viruses on 293 cells without contamination of wt Ad7. Viruses that were picked after plaque purification on 293-ORF6 cells (Brough et al., 1996) were shown to have incorporated Ad7 E1B sequences by non-homologous recombination. Thus, efficient propagation of Ad7 recombinant viruses proved possible only in the presence of Ad7-E1B expression and Ad5-E4-ORF6 expression. The E1B proteins are known to interact with cellular as well as viral proteins (Bridge et al., 1993; White, 1995). Possibly, the complex formed between the E1B 55K protein and E4-ORF6 which is necessary to increase mRNA export of viral proteins and to inhibit export of most cellular mRNAs, is critical and in some way serotype specific. The above experiments suggest that the E1A proteins of Ad5 are capable of complementing an Ad7-E1A deletion and that Ad7-E1B expression in adenovirus packaging cells on itself is not enough to generate a stable complementing cell line. To test whether one or both of the Ad35-E1B proteins is/are the limiting factor in efficient Ad35 vector propagation on PER.C6 cells, we have generated an Ad35 adapter plasmid that does contain the E1B promoter and E1B sequences but lacks the promoter and the coding region for E1A. Hereto, the left end of wtAd35 DNA was amplified using the primers 35F1 and 35R4 (both described in Example 7) with Pwo DNA polymerase (Roche) according to the manufacturer's instructions. The 4.6 kb PCR product was purified using the PCR purification kit (LTI) and digested with SnaBI and ApaI enzymes. The resulting 4.2 kb fragment was then purified from gel using the QIAExII kit (Qiagen). Next, pAdApt35IP1 (Example 7) was digested with SnaBI and ApaI and the 2.6 kb vector-containing fragment was isolated from gel using the GENECLEAN kit (BIO 101, Inc). Both isolated fragments were ligated to give pBr/Ad35.leftITR-pIX. Correct amplification during PCR was verified by a functionality test as follows: The DNA was digested with BstBI to liberate the Ad35 insert from vector sequences and 4 μgr of this DNA was cotransfected with 4 μgr of NotI-digested pWE/Ad35.pIX-rITR (Example 7) into PER.C6 cells. The transfected cells were passaged to T80 flasks at day 2 and again two days later CPE had formed showing that the new pBr/Ad35.leftITR-pIX construct contains functional E1 sequences. The pBr/Ad35.leftITR-pIX construct was then further modified as follows: The DNA was digested with SnaBI and HindIII and the 5′ HindIII overhang was filled in using Klenow enzyme. Religation of the digested DNA and transformation into competent cells (LTI) gave construct pBr/Ad35leftITR-pIXΔE1A. This latter construct contains the left end 4.6 kb of Ad35 except for E1A sequences between bp 450 and 1341 (numbering according to wtAd35, FIG. 6 ) and thus lacks the E1A promoter and most of the E1A coding sequences. pBr/Ad35.leftITR-pIXΔE1A was then digested with BstBI and 2 μgr of this construct was cotransfected with 6 μgr of NotI-digested pWE/Ad35.pIX-rITR (Example 7) into PER.C6 cells. One week following transfection full CPE had formed in the transfected flasks.
This experiment shows that the Ad35-E1A proteins are functionally complemented by Ad5-e1A expression in PER.C6 cells and that at least one of the Ad35-E1B proteins cannot be complemented by Ad5-E1 expression in PER.C6. It further shows that it is possible to make a complementing cell line for Ad35 E1-deleted viruses by expressing Ad35-E1B proteins in PER.C6. Stable expression of Ad35-E1B sequences from integrated copies in the genome of PER.C6 cells may be driven by the E1B promoter and terminated by a heterologous poly-adenylation signal like, but not limited to, the HBVpA. The heterologous pA signal is necessary to avoid overlap between the E1B insert and the recombinant vector, since the natural E1B termination is located in the pIX transcription unit that has to be present on the adenoviral vector. Alternatively, the E1B sequences may be driven by a heterologous promoter like, but not limited to, the human PGK promoter or by an inducible promoter like, but not limited to, the 7xtetO promoter (Gossen and Bujard, 1992). Also in these cases the transcription termination is mediated by a heterologous pA sequence, e.g., the HBV pA. The Ad35-E1B sequences at least comprise one of the coding regions of the E1B 21K and the E1B 55K proteins located between nucleotides 1611 and 3400 of the wt Ad35 sequence. The insert may also include (part of the) Ad35-E1B sequences between nucleotides 1550 and 1611 of the wt Ad35 sequence.
Example 15
Generation of Producer Cell Lines for the Production of Recombinant Adenoviral Vectors Deleted in Early Region 1 and Early Region 2A
Generation of PER.C6-tTA Cells
Here is described the generation of cell lines for the production of recombinant adenoviral vectors that are deleted in early region 1 (E1) and early region 2A (E2A). The producer cell lines complement for the E1 and E2A deletion from recombinant adenoviral vectors in trans by constitutive expression of both E1 and E2A genes. The pre-established Ad5-E1 transformed human embryo retinoblast (“HER”) cell line PER.C6 (International Patent Appln. WO 97/00326) was further equipped with E2A expression cassettes.
The adenoviral E2A gene encodes a 72 kDa DNA Binding Protein with has a high affinity for single stranded DNA. Because of its function, constitutive expression of DBP is toxic for cells. The ts125E2A mutant encodes a DBP that has a Pro→Ser substitution of amino acid 413. Due to this mutation, the ts125E2A encoded DBP is fully active at the permissive temperature of 32° C., but does not bind to ssDNA at the non-permissive temperature of 39° C. This allows the generation of cell lines that constitutively express E2A, which is not functional and is not toxic at the non-permissive temperature of 39° C. Temperature sensitive E2A gradually becomes functional upon temperature decrease and becomes fully functional at a temperature of 32° C., the permissive temperature.
A. Generation of Plasmids Expressing the Wild Type E2A- or Temperature-Sensitive ts125E2A Gene.
pcDNA3 wtE2A: The complete wild-type early region 2A (E2A) coding region was amplified from the plasmid pBR/Ad.Bam-rITR (ECACC deposit P97082122) with the primers DBPpcr1 and DBPpcr2 using the Expand™ Long Template PCR system according to the standard protocol of the supplier (Boehringer Mannheim). The PCR was performed on a Biometra Trio Thermoblock, using the following amplification program: 94° C. for two minutes, one cycle; 94° C. for ten seconds +51° C. for 30 seconds +68° C. for two minutes, one cycle; 94° C. for ten seconds +58° C. for 30 seconds +68° C. for two minutes, ten cycles; 94° C. for ten seconds +58° C. for 30 seconds +68° C. for two minutes with ten seconds extension per cycle, 20 cycles; 68° C. for five minutes, one cycle. The primer DBPpcr1: CGG GAT CCG CCA CCA TGG CCA GTC GGG AAG AGG AG (5′ to 3′) (SEQ ID NO:80) contains a unique BamHI restriction site (underlined) 5′ of the Kozak sequence (italic) and start codon of the E2A coding sequence. The primer DBPpcr2: CGG AAT TCT TAA AAA TCA AAG GGG TTC TGC CGC (5′ to 3′) (SEQ ID NO:81) contains a unique EcoRI restriction site (underlined) 3′ of the stop codon of the E2A coding sequence. The bold characters refer to sequences derived from the E2A coding region. The PCR fragment was digested with BamHI/EcoRI and cloned into BamHI/EcoRI-digested pcDNA3 (Invitrogen), giving rise to pcDNA3 wtE2A.
pcDNA3tsE2A: The complete ts125E2A-coding region was amplified from DNA isolated from the temperature sensitive adenovirus mutant H5ts125. The PCR amplification procedure was identical to that for the amplification of wtE2A. The PCR fragment was digested with BamHI/EcoRI and cloned into BamHI/EcoRI-digested pcDNA3 (Invitrogen), giving rise to pcDNA3tsE2A. The integrity of the coding sequence of wtE2A and tsE2A was confirmed by sequencing.
B. Growth Characteristics of Producer Cells for the Production of Recombinant Adenoviral Vectors Cultured at 32°, 37° and 39° C.
PER.C6 cells were cultured in DMEM (Gibco BRL) supplemented with 10% FBS (Gibco BRL) and 10 mM MgCl 2 in a 10% CO 2 atmosphere at 32° C., 37° C. or 39° C. At day 0, a total of 1×10 6 PER.C6 cells were seeded per 25 cm 2 tissue culture flask (Nunc) and the cells were cultured at 32° C., 37° C. or 39° C. At days 1-8, cells were counted. FIG. 30 shows that the growth rate and the final cell density of the PER.C6 culture at 39° C. are comparable to that at 37° C. The growth rate and final density of the PER.C6 culture at 32° C. were slightly reduced as compared to that at 37° C. or 39° C. No significant cell death was observed at any of the incubation temperatures. Thus, PER.C6 performs very well both at 32° C. and 39° C., the permissive and non-permissive temperature for ts125E2A, respectively.
C. Transfection of PER.C6 with E2A Expression Vectors; Colony Formation and Generation of Cell Lines
One day prior to transfection, 2×10 6 PER.C6 cells were seeded per 6 cm tissue culture dish (Greiner) in DMEM, supplemented with 10% FBS and 10 mM MgCl 2 and incubated at 37° C. in a 10% CO 2 atmosphere. The next day, the cells were transfected with 3, 5 or 8 μg of either pcDNA3, pcDNA3 wtE2A or pcDNA3tsE2A plasmid DNA per dish, using the LipofectAMINE PLUSä Reagent Kit according to the standard protocol of the supplier (Gibco BRL), except that the cells were transfected at 39° C. in a 10% CO 2 atmosphere. After the transfection, the cells were constantly kept at 39° C., the non-permissive temperature for ts125E2A. Three days later, the cells were put in DMEM supplemented with 10% FBS, 10 mM MgCl 2 and 0.25 mg/ml G418 (Gibco BRL), and the first G418 resistant colonies appeared at ten days post transfection. As shown in Table 1, there was a dramatic difference between the total number of colonies obtained after transfection of pcDNA3 (˜200 colonies) or pcDNA3tsE2A (˜100 colonies) and pcDNA3 wtE2A (only four colonies). These results indicate that the toxicity of constitutively expressed E2A can be overcome by using a temperature sensitive mutant of E2A (ts125E2A) and culturing of the cells at the non-permissive temperature of 39° C.
From each transfection, a number of colonies were picked by scraping the cells from the dish with a pipette. The detached cells were subsequently put into 24-well tissue culture dishes (Greiner) and cultured further at 39° C. in a 10% CO 2 atmosphere in DMEM, supplemented with 10% FBS, 10 mM MgCl 2 and 0.25 mg/ml G418. As shown in Table 1, 100% of the pcDNA3 transfected colonies (4/4) and 82% of the pcDNA3tsE2A transfected colonies (37/45) were established to stable cell lines (the remaining eight pcDNA3tsE2A transfected colonies grew slowly and were discarded). In contrast, only one pcDNA3 wtE2A-transfected colony could be established. The other three died directly after picking.
Next, the E2A expression levels in the different cell lines were determined by Western blotting. The cell lines were seeded on 6-well tissue culture dishes and sub-confluent cultures were washed twice with PBS (NPBI) and lysed and scraped in RIPA (1% NP-40, 0.5% sodium deoxycholate and 0.1% SDS in PBS, supplemented with 1 mM phenylmethylsulfonylfluoride and 0.1 mg/ml trypsin inhibitor). After 15 minutes incubation on ice, the lysates were cleared by centrifugation. Protein concentrations were determined by the Bio-Rad protein assay, according to standard procedures of the supplier (BioRad). Equal amounts of whole-cell extract were fractionated by SDS-PAGE on 10% gels. Proteins were transferred onto Immobilon-P membranes (Millipore) and incubated with the αDBP monoclonal antibody B6. The secondary antibody was a horseradish-peroxidase-conjugated goat anti mouse antibody (BioRad). The Western blotting procedure and incubations were performed according to the protocol provided by Millipore. The complexes were visualized with the ECL detection system according to the manufacturer's protocol (Amersham). FIG. 31 shows that all of the cell lines derived from the pcDNA3tsE2A transfection expressed the 72-kDa E2A protein (left panel, lanes 4-14; middle panel, lanes 1-13; right panel, lanes 1-12). In contrast, the only cell line derived from the pcDNAwtE2A transfection did not express the E2A protein (left panel, lane 2). No E2A protein was detected in extract from a cell line derived from the pcDNA3 transfection (left panel, lane 1), which served as a negative control. Extract from PER.C6 cells transiently transfected with pcDNA3ts125 (left panel, lane 3) served as a positive control for the Western blot procedure. These data confirmed that constitutive expression of wtE2A is toxic for cells and that using the ts125 mutant of E2A could circumvent this toxicity.
D. Complementation of E2A Deletion in Adenoviral Vectors on PER.C6 Cells Constitutively Expressing Full-Length ts125E2A
The adenovirus Ad5.d1802 is an Ad5 derived vector deleted for the major part of the E2A coding region and does not produce functional DBP. Ad5.d1802 was used to test the E2A trans-complementing activity of PER.C6 cells constitutively expressing ts125E2A. Parental PER.C6 cells or PER.C6tsE2A clone 3-9 were cultured in DMEM, supplemented with 10% FBS and 10 mM MgCl 2 at 39° C. and 10% CO 2 in 25 cm 2 flasks and either mock-infected or infected with Ad5.d1802 at an m.o.i. of 5. Subsequently the infected cells were cultured at 32° C. and cells were screened for the appearance of a cytopathic effect (“CPE”) as determined by changes in cell morphology and detachment of the cells from the flask. Full CPE appeared in the Ad5.d1802 infected PER.C6tsE2A clone 3-9 within two days. No CPE appeared in the Ad5.d1802 infected PER.C6 cells or the mock-infected cells. These data showed that PER.C6 cells constitutively expressing ts125E2A complemented in trans for the E2A deletion in the Ad5.d1802 vector at the permissive temperature of 32° C.
E. Serum-Free Suspension Culture of PER.C6tsE2A Cell Lines
Large-scale production of recombinant adenoviral vectors for human gene therapy requires an easy and scaleable culturing method for the producer cell line, preferably a suspension culture in medium devoid of any human or animal constituents. To that end, the cell line PER.C6tsE2A c5-9 (designated c5-9) was cultured at 39° C. and 10% CO 2 in a 175 cm 2 tissue culture flask (Nunc) in DMEM, supplemented with 10% FBS and 10 mM MgCl 2 . At sub-confluency (70-80% confluent), the cells were washed with PBS (NPBI) and the medium was replaced by 25 ml serum free suspension medium Ex-cell™ 525 (JRH) supplemented with 1×L-Glutamine (Gibco BRL), hereafter designated SFM. Two days later, cells were detached from the flask by flicking and the cells were centrifuged at 1,000 rpm for five minutes. The cell pellet was re-suspended in 5 ml SFM and 0.5 ml cell suspension was transferred to a 80 cm 2 tissue culture flask (Nunc), together with 12 ml fresh SFM. After two days, cells were harvested (all cells are in suspension) and counted in a Burker cell counter. Next, cells were seeded in a 125 ml tissue culture Erlenmeyer (Corning) at a seeding density of 3×10 5 cells per ml in a total volume of 20 ml SFM. Cells were further cultured at 125 RPM on an orbital shaker (GFL) at 39° C. in a 10% CO 2 atmosphere. Cells were counted at day 1-6 in a Burker cell counter. In FIG. 4 , the mean growth curve from eight cultures is shown. PER.C6tsE2A c5-9 performed well in serum free suspension culture. The maximum cell density of approximately 2×10 6 cells per ml is reached within five days of culture.
F. Growth Characteristics of PER.C6 and PER.C6/E2A at 37° C. and 39° C.
PER.C6 cells or PER.C6ts125E2A (c8-4) cells were cultured in DMEM (Gibco BRL) supplemented with 10% FBS (Gibco BRL) and 10 mM MgCl 2 in a 10% CO 2 atmosphere at either 37° C. (PER.C6) or 39° C. (PER.C6ts125E2A c8-4). At day 0, a total of 1×10 6 cells were seeded per 25 cm 2 tissue culture flask (Nunc) and the cells were cultured at the respective temperatures. At the indicated time points, cells were counted. The growth of PER.C6 cells at 37° C. was comparable to the growth of PER.C6ts125E2A c8-4 at 39° C. ( FIG. 33 ). This shows that constitutive expression of ts125E2A encoded DBP had no adverse effect on the growth of cells at the non-permissive temperature of 39° C.
G. Stability of PER.C6ts125E2A
For several passages, the PER.C6ts125E2A cell line clone 8-4 was cultured at 39° C. and 10% CO 2 in a 25 cm 2 tissue culture flask (Nunc) in DMEM, supplemented with 10% FBS and 10 mM MgCl 2 in the absence of selection pressure (G418). At sub-confluency (70-80% confluent), the cells were washed with PBS (NPBI) and lysed and scraped in RIPA (1% NP-40, 0.5% sodium deoxycholate and 0.1% SDS in PBS, supplemented with 1 mM phenylmethylsulfonylfluoride and 0.1 mg/ml trypsin inhibitor). After 15 minutes incubation on ice, the lysates were cleared by centrifugation. Protein concentrations were determined by the BioRad protein assay, according to standard procedures of the supplier (BioRad). Equal amounts of whole-cell extract were fractionated by SDS-PAGE in 10% gels. Proteins were transferred onto Immobilon-P membranes (Millipore) and incubated with the aDBP monoclonal antibody B6. The secondary antibody was a horseradish-peroxidase-conjugated goat anti mouse antibody (BioRad). The Western blotting procedure and incubations were performed according to the protocol provided by Millipore. The complexes were visualized with the ECL detection system according to the manufacturer's protocol (Amersham). The expression of ts125E2A encoded DBP was stable for at least 16 passages, which is equivalent to approximately 40 cell doublings ( FIG. 34 ). No decrease in DBP levels was observed during this culture period, indicating that the expression of ts125E2A was stable, even in the absence of G418 selection pressure.
Example 16
Generation of tTA Expressing Packaging Cell Lines
A. Generation of a Plasmid from which the tTA Gene is Expressed
pcDNA3.1-tTA: The tTA gene, a fusion of the tetR and VP16 genes, was removed from the plasmid pUHD 15-1 (Gossen and Bujard, 1992) by digestion using the restriction enzymes BamHI and EcoRI. First, pUHD15-1 was digested with EcoRI. The linearized plasmid was treated with Klenow enzyme in the presence of dNTPs to fill in the EcoRI sticky ends. Then, the plasmid was digested with BamHI. The resulting fragment, 1025 bp in length, was purified from agarose. Subsequently, the fragment was used in a ligation reaction with BamHI/EcoRV-digested pcDNA 3.1 HYGRO (−) (Invitrogen) giving rise to pcDNA3.1-tTA. After transformation into competent E. Coli DH5α (Life Techn.) and analysis of ampicillin resistant colonies, one clone was selected that showed a digestion pattern as expected for pcDNA3.1-tTA.
B. Transfection of PER.C6 and PER.C6/E2A with the tTA Expression Vector; Colony Formation and Generation of Cell Lines
One day prior to transfection, 2×10 6 PER.C6 or PER.C6/E2A cells were seeded per 60 mm tissue culture dish (Greiner) in Dulbecco's modified essential medium (DMEM, Gibco BRL) supplemented with 10% FBS (JRH) and 10 mM MgCl 2 and incubated at 37° C. in a 10% CO 2 atmosphere. The next day, cells were transfected with 4-8 μg of pcDNA3.1-tTA plasmid DNA using the LipofectAMINE PLUS™ Reagent Kit according to the standard protocol of the supplier (Gibco BRL). The cells were incubated with the LipofectAMINE PLUS™-DNA mixture for four hours at 37° C. and 10% CO 2 . Then, 2 ml of DMEM supplemented with 20% FBS and 10 mM MgCl 2 was added and cells were further incubated at 37° C. and 10% CO 2 . The next day, cells were washed with PBS and incubated in fresh DMEM supplemented with 10% FBS, 10 mM MgCl 2 at either 37° C. (PER.C6) or 39° C. (Per.C6/E2A) in a 10% CO 2 atmosphere for three days. Then, the media were exchanged for selection media; PER.C6 cells were incubated with DMEM supplemented with 10% FBS, 10 mM MgCl 2 and 50 μg/ml hygromycin B (GIBCO) while PER.C6/E2A cells were maintained in DMEM supplemented with 10% FBS, 10 mM MgCl 2 and 100 μg/ml hygromycin B. Colonies of cells that resisted the selection appeared within three weeks while nonresistant cells died during this period.
From each transfection, a number of independent, hygromycin-resistant cell colonies were picked by scraping the cells from the dish with a pipette and put into 2.5 cm 2 dishes (Greiner) for further growth in DMEM containing 10% FBS, 10 mM MgCl 2 and supplemented with 50 μg/ml (PERC.6 cells) or 100 μg/ml (PERC.6/E2A cells) hygromycin in a 10% CO 2 atmosphere and at 37° C. or 39° C., respectively.
Next, it was determined whether these hygromycin-resistant cell colonies expressed functional tTA protein. Therefore, cultures of PER.C6/tTA or PER/E2A/tTA cells were transfected with the plasmid pUHC 13-3 that contains the reporter gene luciferase under the control of the 7xtetO promoter (Gossens and Bujard, 1992). To demonstrate that the expression of luciferase was mediated by tTA, one half of the cultures were maintained in medium without doxycycline. The other half was maintained in medium with 8 μg/ml doxycycline (Sigma). The latter drug is an analogue of tetracycline and binds to tTA and inhibits its activity. All PER.C6/tTA and PER/E2A/tTA cell lines yielded high levels of luciferase, indicating that all cell lines expressed the tTA protein ( FIG. 35 ). In addition, the expression of luciferase was greatly suppressed when the cells were treated with doxycycline. Collectively, the data showed that the isolated and established hygromycin-resistant PER.C6 and PER/E2A cell clones all expressed functional tTA.
TABLE I Elution log 10 Serotype [NaCl] mM VP/ml CCID50 VP/CCID50 ratio 1 597 8.66 × 10 10 5.00 × 10 7 3.2 2 574 1.04 × 10 12 3.66 × 10 11 0.4 3 131 1.19 × 10 11 1.28 × 10 7 4.0 4 260 4.84 × 10 11 2.50 × 10 8 3.3 5 533 5.40 × 10 11 1.12 × 10 10 1.7 6 477 1.05 × 10 12 2.14 × 10 10 1.7 7 328 1.68 × 10 12 2.73 × 10 9 2.4 9 379 4.99 × 10 11 3.75 × 10 7 4.1 10 387 8.32 × 10 12 1.12 × 10 9 3.9 12 305 3.64 × 10 11 1.46 × 10 7 4.4 13 231 4.37 × 10 12 7.31 × 10 8 3.8 15 443 5.33 × 10 12 1.25 × 10 9 3.6 16 312 1.75 × 10 12 5.59 × 10 8 3.5 17 478 1.39 × 10 12 1.45 × 10 9 3.0 19 430 8.44 × 10 11 8.55 × 10 7 4.0 20 156 1.41 × 10 11 1.68 × 10 7 3.9 21 437 3.21 × 10 11 1.12 × 10 8 3.5 22 365 1.43 × 10 12 5.59 × 10 7 3.4 23 132 2.33 × 10 11 1.57 × 10 7 4.2 24 405 5.12 × 10 12 4.27 × 10 8 4.1 25 405 7.24 × 10 11 5.59 × 10 7 4.1 26 356 1.13 × 10 12 1.12 × 10 8 4.0 27 342 2.00 × 10 12 1.28 × 10 8 4.2 28 347 2.77 × 10 12 5.00 × 10 7 4.7 29 386 2.78 × 10 11 2.00 × 10 7 4.1 30 409 1.33 × 10 12 5.59 × 10 8 3.4 31 303 8.48 × 10 10 2.19 × 10 7 3.6 33 302 1.02 × 10 12 1.12 × 10 7 5.0 34 425 1.08 × 10 12 1.63 × 10 11 0.8 35 446 3.26 × 10 12 1.25 × 10 11 1.4 36 325 9.26 × 10 12 3.62 × 10 9 3.4 37 257 5.86 × 10 12 2.8 × 10 9 3.3 38 337 3.61 × 10 12 5.59 × 10 7 4.8 39 241 3.34 × 10 11 1.17 × 10 7 4.5 42 370 1.95 × 10 12 1.12 × 10 8 4.2 43 284 2.42 × 10 12 1.81 × 10 8 4.1 44 295 8.45 × 10 11 2.00 × 10 7 4.6 45 283 5.20 × 10 11 2.99 × 10 7 4.2 46 282 9.73 × 10 12 2.50 × 10 8 4.6 47 271 5.69 × 10 11 3.42 × 10 7 4.2 48 264 1.68 × 10 12 9.56 × 10 8 3.3 49 332 2.20 × 10 12 8.55 × 10 7 4.4 50 459 7.38 × 10 12 2.80 × 10 9 3.4 51 450 8.41 × 10 11 1.88 × 10 8 3.7
Legend to Table I:
All human adenoviruses used in the neutralization experiments were produced on PER.C6 cells (Fallaux et al., 1998) and purified on CsCl as described in example 1. The NaCl concentration at which the different serotypes eluted from the HPLC column is shown. Virus particles/ml (VP/ml) were calculated from an Ad5 standard. The titer in the experiment (CCID50) was determined on PER.C6 cells as described in Example 1 by titrations performed in parallel with the neutralization experiment. The CCID50 is shown for the 44 viruses used in this study and reflects the dilution of the virus needed to obtain CPE in 50% of the wells after five days. The ratio of VP/CCID50 is depicted in log 10 and is a measurement of the infectivity of the different batches on PER.C6 cells.
TABLE II
AdApt35.LacZ viruses escape neutralization by human serum.
Human serum dilution
no
Virus
serum
10×
50×
250×
1250×
6250×
AdApt5.LacZ
100%
0%
0%
1%
40%
80%
moi: 5
VP/cell
AdApt35.LacZ
100%
100%
100%
100%
100%
100%
250 μl
crude lysate
TABLE III
Percentage of synovial fluid samples containing neutralizing
activity (NA) to wt adenoviruses of different serotypes.
% of SF samples with NA
% of SF samples with NA
(all positives)
(positives at ≧64× dilution)
Ad5
72
59
Ad26
66
34
Ad34
45
19
Ad35
4
0
Ad48
42
4
TABLE IV
The numbers of foci obtained with the different
E1 expression constructs in BRK transformation experiments.
Average # of foci/dish:
Construct
1 μgr
5 μgr
Experiment 1
pIG.E1A.E1B
nd
60
pIG.E1A.E1B
nd
35
pRSVAd35E1
0
3
pIG.Ad35.E1
3
7
Experiment 2
pIG.E1A.E1B
37
nd
pIG.Ad35.E1
nd
2
Experiment 3
pIG.E1A.E1B
nd
140
pIG.Ad35.E1
nd
20
pIG270
nd
30
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BACKGROUND
Floors in buildings get dirty with use and must be periodically cleaned, so specialized equipment has been developed for the purpose. In particular, the requirements for floor cleaning in public, commercial, institutional and industrial buildings have led to the development of various specialized floor sweeping and scrubbing machines. One class of such equipment is comprised of rotary broom sweepers, in which a rotating cylindrical brush contacts the floor and throws loose debris into a collection hopper which is periodically emptied. Another class is comprised of scrubbers. These machines apply cleaning solution from an onboard tank to the floor, agitate it with one or more rotating brushes to loosen soilage that is adhered to the floor and suspend it in the cleaning solution. Then they pick up the soiled solution with a vacuum pickup squeegee and store it in an onboard tank for later emptying. The various uses to which buildings are put result in many different floor conditions, some of which are best cleaned by sweepers and some by scrubbers. Many buildings require both sweeping and scrubbing at different times or in different areas. This necessitates investing in both a sweeper and a scrubber, which is a substantial expense.
To reduce this investment there have been combination machines built which could perform both sweeping and scrubbing functions. One class of these is comprised of sweepers with scrubber attachments. In these there is a prime mover which is equipped with a dry debris hopper and a dust control system, in which configuration the machine functions as a sweeper. On occasion the hopper may be removed and a separate scrubber attachment installed in its place. The attachment will contain a tank for supplying cleaning solution to the floor, usually a specialized scrubbing brush, and a vacuum pickup squeegee for removing soiled solution from the floor. The attachment will also provide a tank for storing the soiled solution. These machines are effective and ar widely used. However, the cost of the separate scrubber attachment is substantial, and the time involved in changing from one mode of operation to the other adds to the operating expense.
There are also so called sweeper-scrubbers, which are machines that can either sweep or scrub without removing or adding any parts. These typically have a sweeping brush that throws debris into a hopper, and one or more other brushes that scrub. The sweeping brush and the scrubbing brush are arranged in tandem, and the added elements increase the length of the machine, with an attendant loss in maneuverability. There may be some compromise in performance; for example, the sweeper hopper may be smaller than customary, or dust control may not be provided. And the added elements increase the cost of such machines over the cost of single purpose scrubbers and sweepers.
The present invention overcome the above described shortcomings of the prior art and offers other advantages by achieving the following objects:
1. One machine which can function as a sweeper complete with dust control or as a floor scrubber complete with vacuum squeegee pickup of scrub water without removing or adding any parts.
2. One machine which can be changed from operating in sweeping mode to operating in scrubbing mode or vice versa by a machine operator at any time by manipulating one or a few conveniently located controls.
3. A compact machine for maximum maneuverability, which provides the functions of a sweeper and a scrubber in one machine which is essentially no longer than an equivalent single purpose sweeper or scrubber while retaining typical hopper and tank volumes.
4. A combination sweeping and scrubbing machine which does not require both a brush for sweeping and another brush or brushes for scrubbing, but which has one brush that is the main cleaning tool in both the sweeping mode and the scrubbing mode.
5. A combination sweeping and scrubbing machine which uses a single debris hopper to receive and store debris in both sweeping and scrubbing modes. When in the scrubbing mode this hopper functions to receive debris and scrub water from the floor and to retain the debris while returning the scrub water back to the floor so that no vacuum pickup is needed in said debris hopper to remove water from it.
6. A combination sweeping and scrubbing machine which is equipped with only one tank for maximum compactness, this one tank serving to hold cleaning solution to be dispensed to a floor to be scrubbed and also to receive soiled cleaning solution that is recovered from the scrubbed floor by a vacuum pickup squeegee.
7. A combination sweeping and scrubbing machine which in its scrubbing mode recycles a substantial part of its supply of scrub water by applying it to the floor more than once, and thereby extends its run time as compared to a machine which only uses its supply of scrub water once.
8. A single tank for a combination sweeping and scrubbing machine in which the lower portion of the tank is made to serve as a sediment sump by placing the outlet somewhat above the bottom of the tank.
9. A combination sweeping and scrubbing machine which uses fewer parts than prior art sweeper-scrubbers, and consequently has a lower manufacturing cost and fewer service problems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of the combination sweeping and scrubbing machine of the present invention.
FIG. 2 is a view on an enlarged scale showing the detailed construction of the portion of the machine in the circle 2 in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the combination sweeping and scrubbing machine of the present invention is shown generally at 10 in FIG. 1.
Its structural construction is similar to that of the machines shown in U.S. Pat. Nos. 4,580,313 and 4,819,676. These patents are incorporated here by reference and the reader may refer to them for details of construction. It will then only be necessary to give a functional description of the machine here, referring to the schematic drawing of FIG. 1, and then describe the areas of innovative difference from the prior art.
The machine is power driven in a conventional manner by a gasoline engine or by one or more battery powered electric motors. It is designed to be operated by an attendant walking behind it who guides it with handlebar 14 in a normal direction of travel indicated by arrow 12. Other controls needed by the operator are provided, but are not shown as they are conventional and well known in the art The machine is supported on a floor to be swept or scrubbed by two front wheels 16, which also drive it, and one rear caster wheel 18. A cylindrical brush 20, which rotates bottom side forward as indicated by arrow 22, serves to either sweep debris off the floor when the machine is operating in a sweeping mode or scrub the floor and also sweep up debris when a scrubbing mode is in use. The brush will be more fully described later.
A debris hopper 24 is mounted in the machine in front of the brush according to the referenced patents. In its rear wall is a large opening 26 through which debris is flung by the brush. Debris will thus accumulate in the hopper, which may be periodically removed and emptied. Certain details of the hopper construction will be described in more detail later in connection with the scrubbing mode operation of the machine.
Above the hopper is a pleated air filter 28 in a filter enclosure 30 which is mounted as described in U.S. Pat. No. 4,580,313. The filter housing is hinged at 31 and may be swung up to provide clearance for lifting out the hopper as described in U.S. Pat. No. '313. An exhaust blower 32 pulls dusty air from around the brush, through the hopper and filter, where the dust is removed, and exhausts it to atmosphere, thereby controlling any dust stirred up by the brush during sweeping. A butterfly valve 34 in the fan inlet duct may be opened or closed by a bowdon wire control 36 or other suitable control. The butterfly valve will be open when the fan is used for dust control during sweeping as described above.
From the above it will be seen that the sweeping mode. operation of the machine is quite conventional. The features which allow it to also function as a scrubber will now be discussed. Mounted at the rear of the machine is a tank 38 which may be filled to a level 40 with a desired scrubbing solution, most commonly water to which detergent has been added. The water level is chosen to utilize most of the tank capacity while still leaving an air plenum in the tank above the solution level. A pump 42 is mounted on the body structure of the machine. Model 2100-761 made by Flojet Corp. of Irvine, California is suitable, and others may be used also. The pump may be started and stopped by switch 44, which is conveniently located for the operator. Mounted in tank 38 is a fine mesh screen filter 46 which is connected to the inlet port of pump 42 by a length of flexible tubing 48.
When the pump 42 is turned on by switch 44 it will draw solution from the tank 38 and deliver it through tubes 50, 52 and 54 to spray nozzle 56, which sprays it on the floor. Part of the flow from the pump is bypassed through the tee connector 62 and a small diameter tube 58 to the air plenum in the top of tank 38, but the pump is sized to allow for this and still deliver the desired amount to the floor. The purpose of bypass tube 58 is to serve as a syphon breaker. Without it some scrubbing solution would continue to flow from the tank to the nozzle by syphon action after the pump was shut off because the pump does not serve as a positive shutoff when it is not running. Eliminating this unwanted afterflow also dictates routing tube 52 through a point which is higher than any level that solution will ever reach in the tank.
Solution supply tubes 52 and 54 are joined by a quick connect/disconnect coupling 60. One suitable coupling is supplied by Colder Products Company of St. Paul, Minnesota. When it is desired to empty debris hopper 24 the filter housing 30 is swung up out of the way, after which coupling 60 is easily disconnected. It is then possible to remove hopper 24 for emptying.
During a scrubbing operation the brush 20 will fling water forward into the hopper. If any of this were to reach filter 28 it would have an adverse effect on the filter. To prevent this two sheet metal baffles 64 and 65 are installed in the hopper as shown, extending across its full width.
The water flung forward by the brush accumulates in the bottom of the hopper. Provision is made to drain this out by piercing a row of 0.25×1.00 inch drain slots in the bottom of the hopper. Their location is shown at 66 in FIG. 2, and they are spaced every four inches across the hopper. The water runs out through them back onto the floor, where it may be recycled for further scrubbing by the brush, or may pass back to the pickup squeegee and be sucked up into the tank 38.
In a scrubbing operation there is typically a certain amount of sand, dirt, loose debris and other soilage from the floor that is also thrown by the brush into the hopper. A baffle is provided to protect the drain slots 66 from being plugged up by this material. A sheet rubber combination sweeping lip an baffle 68 is held between an upper retainer 70 and a lower retainer 72. These parts extend across the width of the hopper. The baffle 68 has 0.25×1.00 inch notches 74 along its forward edge spaced every four inches across the hopper, in staggered relationship to the drain slots 66. This design is intended to retain dirt in the hopper, pass water down to the drain slots, and keep the slots open.
The brush 20 has overall dimensions that are the same as might be used in a sweeper of comparable size. In an exemplary machine the outside diameter of the brush is ten inches and the bristles are 2.5 inches long. The bristle material is polypropylene because of its excellent dimensional stability even when wet. A somewhat stiffer fill is used than in a normal sweeping brush to improve the scrubbing performance. Stiffness will be limited by the permissible power draw, but it can be allowed as much as an equivalent scrubber. An exemplary machine uses a bristle mix of 0.015, 0.025 and 0.035-inch x-shaped polypropylene bristles. This gives good sweeping and scrubbing performance and holds the power draw within allowable limits. Thus one brush is able to serve in both sweeping and scrubbing modes, and no changing of the brush is needed when going from one mode to the other.
An exhaust blower 76 provides vacuumized air for dust control during the sweeping mode and for water pickup during the scrubbing mode. It draws in air through intake duct 78 and exhausts it to atmosphere. During the sweeping mode the butterfly valve 34 in the intake duct will be open and air will be drawn from around the brush 22, through the hopper 24 and air filter 28 to control dust stirred up by the brush. Air will also be drawn from branch duct 80, but it is smaller than the main duct 78 and passes relatively less air. The fan has more capacity than is required for effective dust control and will pull enough air from around the brush to control dusting in spite of branch duct 80 being open.
During the scrubbing mode the butterfly valve 34 will be closed so all the intake air to the fan will come from branch duct 80. There will be less air flow, but at a higher vacuum, than in the sweeping mode. Duct 80 is connected to the air plenum in the top of tank 38. A ball float valve 82 in a cage 83 is arranged to shut off the airflow in case the water level in the tank gets high enough to enter the branch duct 80. This is for the protection of the fan and is completely conventional
A pickup squeegee 84 is attached to the rear of the machine with a linkage 85. A suction hose 86 connects the pickup squeegee to the air plenum in the top of tank 38. All of this is conventional, and the pickup squeegee acts in conventional fashion to remove soiled scrubbing solution from the floor and deposit it in the tank 38. The heavier debris and sludge will settle to the bottom of the tank, which thus serves as a sludge sump. Intake filter screen 46 is set high enough in the tank to be above this sump and so provides relatively clear water for application to the floor. The machine thus recycles the scrub water that has been used and picked up and thereby provides a substantially increased running time between water refills compared to a machine which does not recycle.
A link 90 connects the squeegee assembly to a handle 88. By lifting on this handle an operator can lift the squeegee off the floor. A detent, not shown, is provided for retaining the handle in this raised position so that the squeegee can be kept off the floor during sweeping mode operation. When entering scrub mode the operator can easily remove the handle from the detent and lower the squeegee to the floor.
Operation of the machine in either sweeping mode or scrubbing mode is conventional and will be familiar to anyone accustomed to operating machines of this class. Changing over from one mode to the other is quick and easy. An operator who has been sweeping and who wants to scrub only has to operate three controls. First, the bowdon wire control 36 is moved to close butterfly valve 34. Second, the squeegee lift lever 88 is moved to lower the squeegee 84 to the floor. Third, the pump switch 44 is moved to turn on the pump 42, thereby starting a flow of scrubbing solution to the floor. Scrubbing operation will commence and continue. Converting back to sweeping mode is equally simple, requiring only a reverse movement of the above three controls. The flow of scrubbing solution will cease and sweeping mode operation will begin.
As an alternative configuration, at somewhat higher cost, it would be possible to interconnect the three controls so that moving only one would effect the change from one mode to the other. For example, bowdon wire 36 could be connected to squeegee lever 88 instead of to the control knob shown, so that movement of the lever would open or close the butterfly valve as well as raise or lower the squeegee. Also, toggle switch 44 could be replaced with a push button switch located so that movement of the squeegee lever would operate the push button switch. Then all that would be needed to change from one mode to the other would be to move the squeegee lever. However, the controls as shown are easy to operate, and the additional refinements described or other variations in control configuration might not be worth their additional cost.
Other variations in the invention are also possible, as a person skilled in the art will realize. For example, at least in a battery powered model, it may be desirable to replace vacuum blower 76 with two blowers, each driven by its own electric motor. One blower would be connected to the air filter and would be tailored for the relatively large volume, low vacuum airflow typically used for dust control. The other blower would be connected to the top of tank 38 and would be specifically designed to supply the relatively low volume, high vacuum airflow typically needed for effective water pickup. Both blowers would be controlled by suitable switches readily accessible to the operator. This option of using two blowers instead of one could be accommodated within the limits of the invention.
The preferred embodiment of the invention has been described as a walk behind machine, or a machine attended by an operator walking behind it. It would be possible to build such a machine on a larger scale so that it could accommodate an operator riding on it and still embody the invention, which is not dependent on the scale of the machine or a walking operator.
As with many machine designs, it would also be possible to transpose the position of the major elements. Thus the forward throwing brush 22 and front hopper 24 could be replaced with a brush sweeping over its top into a hopper behind it, which is a familiar design in the art. The tank 38 would be moved to the front of the machine and the squeegee 84 would be under the hopper at the rear of the machine. Such a transposition of machine elements would not affect the essential features of the invention.
Whereas the preferred form and several variations o the invention have been shown, described, and suggested, it should be understood that suitable additional modifications, changes, substitutions and alterations may be made without departing from the invention's fundamental theme. It is therefore wished that the invention be unrestricted except as by the appended claims. | A combination floor sweeping and scrubbing machine is as compact and maneuverable as an equivalent machine which only sweeps or scrubs, while retaining typical hopper and tank volumes. Its operator can change it from sweeping to scrubbing or vice versa at any time by moving a few controls and without adding or removing any parts. It has one debris hopper and one horizontal cylindrical rotating brush and they function in both the sweeping and scrubbing modes. A vacuum system supplies dust control during sweeping and vacuum pickup of dirty solution during scrubbing. In the scrubbing mode a single tank supplies scrubbing solution and receives dirty solution picked up from the floor. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to automatic washers and more particularly to a centrifugal valve for directing a flow of wash fluid to selected jet sprays
In automatic washing machines there generally is provided a basket for receiving clothes to be washed and an outer tub within which the basket is contained. In vertical axis machines oftentimes there is a central agitator which either oscillates or moves in some other fashion relative to the basket to enhance the flexing of the clothes in the wash fluid to improve washability. Generally in such washers the liquid is introduced into the basket and clothes load through a nozzle fixed relative to the frame of the washer and protruding into an open top area of the basket, such as disclosed in U.S. Pat. No. 4,784,666.
In most constructions, the valves controlling flow to the jet spray device are operated by solenoids or other electrically powered valves.
In some constructions, such as that shown in U.S. Pat. No. 4,784,666 a first inlet nozzle is provided to direct fresh water into the interior of the wash basket and a second nozzle is provided to direct a spray of recirculated wash liquid within the basket.
It would be advantageous in some instances if more than one spray jet were provided to eject a particular type of spray and if there were means provided to automatically direct the wash liquid to the desired spray means.
SUMMARY OF THE INVENTION
The present invention provides a valve means for automatically directing wash liquid to a selected spray jet based upon a predetermined condition of the washer. In a preferred embodiment, the valve provides automatic selection based upon the rotational speed of the basket within the wash tub. That is, when the basket is rotating below a predetermined speed the valve directs wash liquid to a first spray jet and when the basket is rotating above the predetermined speed wash liquid is directed to a second spray jet.
Thus, when the washing machine is in an agitation mode in which the rotational speed of the basket is below the predetermined speed, the wash liquid is directed to a spray jet which enhances agitation. When the washing machine is in a spin mode, the basket is spinning at a rotational speed above the predetermined speed, and the wash liquid is directed to a spray jet for effecting a spray rinsing of the fabric load in the basket.
In a preferred embodiment, the valve comprises a centrifugal valve mounted within the basket to rotate with the basket and having valve members which move in response to the rotation of the wash basket to automatically close one of two outlets depending upon the rotational speed of the basket. In a preferred arrangement a pair of cylindrical chambers, radially oriented and angled from horizontal are each provided with a ball therein and each have an outlet at a lower, radially inward end and an outlet at an upper, radially outward end. When the basket is rotating below the predetermined speed, gravity causes the balls to move and cover the openings at the lower, radially inward end of the chamber, thus opening the outlet at the radially outward, upper end which communicates with the agitation producing spray jet When the rotational speed of the basket is increased, the balls move outwardly under the influence of centrifugal force to block the radially outward openings and to open the radially inward openings which communicate with the rinse spray jet.
The centrifugal valve is preferably mounted on a central post within the basket, concentric with an axis of rotation of the basket.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partially cut away, of an automatic washer embodying the principles of the present invention.
FIG. 2 is a side sectional view showing certain interior components of the washer of FIG. 1.
FIG. 3 is a plan view of the washer with the top wall of the cabinet removed.
FIG. 4 is a side sectional view of a centrifugal valve arrangement as shown in FIG. 2.
FIG. 5 is a side sectional view of the centrifugal valve arrangement of FIG. 4, rotated 90°.
FIG. 6 is a top view of the valve arrangement of FIG. 4.
FIG. 7 is a side elevational view of the spray nozzle of FIG. 2.
FIG. 8 is a top view of the spray nozzle of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is illustrated an automatic washing machine generally at 10 having an exterior cabinet 12 with a top cabinet panel 14 and an openable lid 16 thereon. A control console 18 has a plurality of controls 22 to operate the washer through a series of washing, rinsing and fluid extraction steps. The openable lid 16 provides access to a top opening 24 through which a load of clothes can be placed into a perforate basket 26 which is concentrically carried within an imperforate tub 28.
In the place of a conventional agitator there is a central rigid post 30 which is mounted so as to be fixed relative to the basket 26, and thus to be rotatable with the basket, along a central vertical axis thereof.
Although the post 30 is shown as being a cylindrical member, it should be understood that the post could be any type of vertical structure and could have any type of geometric configuration.
The tub and basket assembly is supported by a conventional suspension system, including a plurality of legs 36 which are secured to a bottom frame 38. Counterbalancing means 40 are secured between the legs and another portion 42 of the suspension system. An electric motor 44 operates to drive the basket 26 in a rotary motion or in an oscillating motion depending on the particular wash cycle.
FIG. 2 shows the interior of the washer in greater detail in which it is seen that there is a drain area 48 positioned at a bottom of the wash tub 28 which connects to an outlet conduit 50. The outlet conduit 50 connects to a pump 52 which may be driven by a second motor 54. Proceeding from the pump 52 is a conduit 55 which has a Y connection with a first leg 56 and a second leg 58. In the Y connection there is a pivotable valve member 60 which is operated by a solenoid 62 to close either the first portion 56 or second portion 58. The second portion 58 extends to a drain for disposal of liquid in that portion and the first portion 56 attaches to an inlet fitting 64 for directing wash liquid into the interior of the post 30.
The inlet fitting 64 is formed on a coupling member 66 which is secured by means of appropriate fastening devices 68 to the portion 42 of the suspension system. The coupling member 6 is thus rigidly held against rotation. The coupling member 66 has formed therein a central passage 70 within which is received a drive member 72 which is to be coupled to the motor 44 either directly as shown in FIG. 2 or indirectly such as by means of belts, gears, clutches or other known power transmission arrangements.
The drive member 72 is free to rotate within the coupling member 66. The coupling member 66 has a radially directed passage 74 therein which opens through the connector 64 and which joins with an annular channel 76 formed in an interior diameter of the passage 70. The drive member 72 has a plurality of radial passages 80 which extend from an outer surface of the drive member to a central bore 82. Thus, wash liquid which flows in through conduit 56 and through passage 74 in the coupling member 66 will flood the annular channel 76 and be caused to flow into the radial passages 80 and into the bore 82 within the drive member. Appropriate seals 84, 86 are provided to prevent leakage of wash liquid along an outer surface of the drive member 72.
The drive member 72 is connected at an upper end, by appropriate fasteners 90 to a plate 92 secured to a spin tube 94. The spin tube 94 is connected to the wash basket 26 by a clamping arrangement at 96 within the post 30 as is known in the art. Thus, the basket will be drivingly connected to the drive member 72. The wash tub 28 is connected in a known manner at 98 to a centering tube 100. Carried within the spin tube 94, and rotating with it is a conduit tube 102 which communicates, at a bottom end 104 thereof with the bore 82 in the drive member 72. A top end 106 of the tube 102 is closed by a cap 108. At least two openings 110 are provided in the tube 102 which communicate with a centrifugal valve arrangement 112.
The centrifugal valve arrangement 112 is shown in greater detail in FIGS. 4-6.
The centrifugal valve arrangement 112 consists of a valve body 114 which has a bottom wall 116 with an opening 118 therethrough for receiving the tube 102. A central horizontal wall 120 is spaced above the bottom wall 116 so as to provide a chamber 122 within the valve body 114 within which are positioned the openings 110 in the tube 102.
The chamber 122 communicates with a pair of passages 124 disposed across from one another which lead radially outwardly from the chamber 122 and, at a radially outward position extend upwardly in a vertical passage portion 126 (FIG. 5). At the top of the vertical passage portions 126 there are two horizontal passages 128, bounded by a lower conical wall 130, which provide communication between the vertical passage portions 126 and a pair of upper chambers 132. The upper chambers 132 are generally cylindrical and are oriented radially, but at an angle from horizontal. Within each of the chambers 132 there is carried a ball 134 which is free to move within the chamber but which is sized to have a diameter approximately the same as the chamber.
When the basket 26 and thus the post 30 are at rest or are oscillating relatively slowly, the balls 134 will position themselves at a lower, radially inward end of the upper chamber 132 under the influence of gravity as shown in full lines in FIG. 2 and in phantom in FIG. 4. As this occurs, wash liquid which is directed by the pump 52 up through the tube 102 will follow the flow path indicated by arrow 140 (FIGS. 4 and 6). The wash liquid will leave the chambers 132 through an opening 142 at an upper, radially outward end of each chamber and will then flow into a space 144 between the valve body 114 and the center post wall 30.
As best seen in FIG. 2, the space 144 communicates at a bottom end 146 with a plurality of radial passages 148 extending along a bottom wall 150 of the basket to a plurality of vertical fins 154 formed at angularly spaced locations on the peripheral wall of the basket. At a junction 156 of the radial passages 148 with the fins 154 there are provided a plurality of apertures 158 providing communication between the radial passages 148 and the interior of the wash basket thus providing a radially inwardly directed spray. Thus, when the wash basket is in the oscillation mode, with the pump 52 running, wash liquid will be recirculated from the drain 48 in the tub 28 to be reintroduced into the basket through the spray apertures 158.
When the wash basket is in a spin mode in which the basket spins at a relatively high rate of speed, centrifugal force causes the balls 134 to automatically move radially outwardly and thus upwardly in the cylindrical chambers 132 to effectively seal the openings 142. Wash liquid from the pump 52 then follows a flow path indicated by arrow 160 (FIGS. 4 and 6). When the wash liquid arrives in the cylindrical chambers 134, with the openings 142 blocked, the wash liquid exits through an opening 162 at a lower end of each cylindrical passage 132 into an annular space 164 between the valve body 114 and the tube 102.
The angle of the chambers 134 is selected, dependent on the weight of the balls 134, such that the balls will move outwardly when the rotation of the basket exceeds a predetermined speed which is greater than the rotational speed of the basket during the agitation portion of the wash cycle, but less than a rotational speed of the basket during the spin portion of the wash cycle.
Again as best seen in FIG. 2, the wash liquid continues to flow upwardly through a short tube 166 secured to a top of the post 30 and exits through a plurality of radial openings 168 into a chamber 170 formed in a nozzle member 172. The nozzle member 172 is shown in greater detail in FIGS. 7 and 8. The chamber 170 of the nozzle member 172 communicates with a vertically oriented spray nozzle opening 174 such that a wide fan of spray will be discharged from the nozzle in a vertical orientation. The nozzle member 172 is rotatingly supported on the short tube 166 and the nozzle opening 174 is oriented in a non-radial direction, preferably a tangential direction, and is offset from the rotational axis of the nozzle member, such that the reaction force of wash liquid leaving the nozzle will cause the nozzle member 172 to rotate on the tube 166 thus causing the nozzle member 172 to rotate relative to the basket. In this manner the wash liquid will be evenly distributed around the entire interior periphery of the basket through a horizontal extent of the full height of the basket while the basket is in the spin mode.
The washing machine construction disclosed herein is particularly suited for use with a wash method such as that disclosed in U.S. Pat. No. 4,784,666, assigned to the assignee of the present invention, and incorporated herein by reference. Specifically, such a washing process contemplates the use of a concentrated detergent solution, in the range of not less than 0.5% to 4% detergent concentration, in a limited amount, being sprayed against a rotating clothes load in the absence of mechanical agitation and recirculated through the clothes load a plurality times to effect a first cleaning step. When such a process is incorporated into the presently described machine, the nozzle member 172 will direct the concentrated wash fluid through the nozzle opening 174 against the spinning clothes load and, in view of the geometry of the nozzle opening, the wash liquid will be directed against the full height of the clothes loa which will be held against the basket wall by centrifugal force With the nozzle member 172 rotating relative to the basket 26, a complete wetting of the clothes load will be assured.
Following the initial concentrated wash step, additional water is introduced into the wash load to dilute the concentrated solution to a more normal or conventional concentration and a second washing step occurs during which time the clothes are agitated within the wash liquid bath. Although the presently disclosed washer does not include a centrally mounted agitator, the fins 154 projecting inwardly of the basket will provide an agitation force against the clothes load within the basket. Also, there may be fins of a similar construction on the post itself which will also impart an agitation force to the clothes load during oscillation of the basket.
Further, during the agitation portion of the wash cycle, wash liquid will be introduced and recirculated into the wash basket through the spray apertures 158 thus providing additional agitation force to the clothes load.
After the second washing step, the wash liquid is drained from the tube and the wash basket is spun to extract as much liquid from the clothes load as possible. Subsequently a rinsing of the clothes load occurs during which time water is sprayed against the rotation clothes load to remove dirt and detergent from the clothes. Part of such a spray rinse step could include a recirculation of the rinse spray which is collected in the tub and is redirected to the spray nozzle 172 by the pump, or a fresh water may be delivered to the rotating clothes load with the collected water directed to drain. The fresh water would be directed into the spinning basket through a stationary nozzle member 180 (FIG. 2).
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art. | A valve is provided for use in an automatic washer which is positioned in a liquid conduit for directing a flow of wash liquid to a first spray jet during a first predetermined condition of the washer and for directing a flow of wash liquid to a second spray jet during a second predetermined condition of the washer. In a particular embodiment of the invention, the valve is a centrifugal valve and the predetermined conditions of the washer are the rotational speeds of the basket. When the basket rotates at a relatively slow speed, such as during agitation, liquid is directed to a spray jet which enhances agitation. When the wash basket is rotated at a high speed, such as during spin, the wash liquid is directed to a spray jet which enhances the rinsing of the wash load. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application No. 60/719,598 entitled, “OBD II READINESS MONITOR TOOL APPARATUS AND METHOD,” filed Sep. 23, 2005, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to automotive vehicles. In particular, it relates to an On-Board Diagnostic II apparatus, method and system.
BACKGROUND OF THE INVENTION
Recently manufactured vehicles are equipped with a special system called On-Board Diagnostic II (OBD II). OBD II monitors all engine and drive train sensors and actuators for shorts, open circuits, lazy sensors and out-of-range values as well as values that do not logically fit with other power train data. Thus, OBD II keeps track of all of the components responsible for emissions and when one of them malfunctions, it signals the vehicle owner by illuminating a Maintenance Indicator Lamp (MIL), such as a check engine indicator. It also stores Diagnostic Trouble Codes (DTCs) designed to help a technician find and repair the emission related problem. OBD II also specifies the means for communicating diagnostic information to equipment used in diagnosing, repairing and testing the vehicle.
An illuminated MIL means that the OBD II system has detected a problem that may cause increased emissions. A blinking MIL indicates a severe engine misfire that can damage the catalytic converter. The MIL is reserved for emission control and monitored systems and may not be used for any other purpose. The “Check Engine,” “Service Engine Soon” or other “engine symbol” message is typically used as an MIL indicator.
The Clean Air Act of 1990 requires inspection and maintenance (I/M) programs to incorporate OBD II testing as part of a vehicle's emissions inspection program. When fully implemented, 1996 and newer model year vehicles registered in a required emission test area must be tested annually. If DTCs are present, or the diagnostic monitor software has not adequately tested the vehicle's emission control systems, the vehicle fails the emissions test. Otherwise, the vehicle passes the emissions test.
In order for a vehicle to pass the OBD II emissions tests, the vehicle under test (VUT) must report that all pertinent (as defined by each state) diagnostic monitors have completed their tests of the vehicle system. Diagnostic monitors that have completed their tests are said to be in a “Ready” state. Diagnostic monitors that have not completed their tests are said to be in a “Not Ready” state. Checking the readiness state of the diagnostic monitors via OBD II was incorporated into emissions testing to prevent owners from attempting to pass vehicles not in compliance by simply clearing the vehicle's Diagnostic Trouble Codes and then quickly retesting the vehicle before the root problem was again detected by the vehicle's on board computer. Clearing the DTCs on a vehicle also sets all of the monitors to the “Not Ready” state. Until the vehicle has been driven under the proper conditions for all of the monitors to execute their tests, the vehicle will not be ready for an emissions test.
The readiness state of the diagnostic monitors of the OBD II system indicates that emission system components have been checked. If a particular monitor is set to “Ready,” the monitor has checked its assigned components and systems. If a problem is found, a DTC is set, and a technician can retrieve the code. When all of the monitors supported on a vehicle are “Ready,” the vehicle is ready for an emissions test.
Unlike DTCs, the readiness state of the diagnostic monitors cannot be manipulated via a scan tool, rather their status is altered by a Drive Cycle, which is a series of specific vehicle operating conditions that enable the diagnostic monitors to test the vehicle's emissions control hardware. As each monitor completes its testing, its readiness state will be set to “Ready.” An example of a simple Drive Cycle is where the vehicle's engine is started, and the vehicle is driven for seven minutes. Then the vehicle is driven in stop-and-go traffic for six minutes including one minute of idling. After which, the vehicle is accelerated to forty-five miles per hour and maintained at that speed for one minute.
Repair shops and drivers may not be aware of when the vehicle is “Ready” to be tested for emissions, or when the required Drive Cycle has been completed in order to properly test the vehicle's emissions. Therefore, repair facilities need an inexpensive tool that enables either an untrained personnel (such as a driver) or a trained repair facility personnel, to determine the status of the OBD II readiness state of the diagnostic monitors while operating the vehicle through normal driving conditions. In addition, repair facilities need to encourage their client to return to their shop after the readiness monitors have been reset to the “Ready” position in order to verify the repair and/or complete the emissions testing.
Accordingly, the tool should simplify the process of determining the readiness state of the readiness monitors in a vehicle by indicating the status of all emission related diagnostic monitors of the vehicle. In addition, a tool is desired that alleviates the need to tie up a shop's expensive scan tool or skilled technician's time to determine the vehicle's readiness status for emissions testing. Accordingly, it is desirable to provide an apparatus and method that is an inexpensive and easy way of indicating a vehicle's readiness status for emissions testing.
SUMMARY OF THE INVENTION
The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments inexpensively and simply provides an indication that, based on the states of all of the pertinent diagnostic monitors, the vehicle either is or is not “Ready” for an emissions test.
In accordance with one embodiment of the present invention, an apparatus for determining emissions testing readiness of a motor vehicle includes a processor operably coupled to a vehicle diagnostic connector to determine a status of at least one readiness monitor, at least one vehicle communication protocol interface operatively coupled to the processor that can allow the processor to communicate with the vehicle, a multiplexer operably coupled to the processor, a computing device interface operably coupled to the multiplexer, a housing surrounding the processor and the at least one vehicle communication protocol interface, the multiplexer, and the computing device, wherein the housing has a port configured to couple to a computing device, and an indicator disposed on the housing, for indicating the readiness of the vehicle for emission testing.
In accordance with another embodiment of the present invention, a method of determining a readiness of a motor vehicle for emissions testing includes providing a tool for determining the readiness of the motor vehicle for emissions testing, determining if the tool is connected to a host, determining the readiness of the motor vehicle for emissions testing by monitoring the status of readiness monitors when the tool is not connected to the host, and alerting through an indicator that the motor vehicle is ready for emissions testing.
In accordance with yet another embodiment of the present invention, a system for determining the readiness of a motor vehicle for emissions testing includes means for processing in communication with means for coupling to a vehicle's computer, wherein the means for processing determines a status of at least one readiness monitor, means for communicating in at least one vehicle communication protocol, wherein the means for communicating is in communication with the means for processing, means for multiplexing operably couples to the means for processing, means for interfacing with a computing device operably coupled to the means for multiplexing, means for housing that surrounds the means for processing, the means for communicating, the means for multiplexing, and the means for interfacing, and means for indicating when the motor vehicle is ready for emissions testing.
In a further embodiment, an apparatus for determining emission repairs of a motor vehicle is provided and includes a processor that can be operably coupled to a vehicle diagnostic connector to determine a status of at least one readiness monitor, at least one vehicle communication protocol interface operatively coupled to the processor and can allow the processor to communicate with the vehicle, a multiplexer operably coupled to the processor, a computing device interface operably coupled to the multiplexer, a housing surrounding the processor, the at least one vehicle communication protocol interface, the multiplexer, and the computing device interface, wherein the housing has a port configured to couple to a computing device, and an indicator disposed on the housing that indicates whether emmissions related repairs were successful.
There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view illustrating a cabled apparatus according to an embodiment of the invention.
FIG. 2 is a plan view of a non-cabled apparatus according to another embodiment of the invention.
FIG. 3 is a schematic illustration of the tools of FIGS. 1 and 2 .
FIG. 4 is a flowchart illustrating steps in accordance with one embodiment of the method of the present invention.
FIG. 5 is another flowchart illustrating steps in accordance with one embodiment of the method of the present invention.
FIG. 6 is a flow chart illustrating the steps residing in the processor.
DETAILED DESCRIPTION
An embodiment of the present invention includes a vehicle device that monitors the status of the I/M readiness monitors to determine if the vehicle is “Ready” for an emissions test. The device will indicate to a driver that the vehicle is ready for emissions testing by alerting the user via, for example, audio and/or visual signals or other alert indicators. Checking the readiness state of the diagnostic monitors allows a driver to save time by not having to return the vehicle for testing only to find out that the vehicle is still not ready for emissions testing.
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. FIG. 1 is a plan view illustrating a cabled device 10 according to an embodiment of the invention. The tool 10 includes generally, a housing 12 and a display 14 . The housing 12 has an opening 16 for coupling a cable 18 to the housing 12 . The display can be any type of display, such as an LCD, that provides any type of information, such as DTCs or that the vehicle is ready or not ready for emissions testing. The cable 18 couples the tool 10 to a connector 20 having an interface 22 that connects to a vehicle's onboard computer (not shown). The cable can be any length desired so that it allows the housing to be at any length away from the vehicle's computer as desired. In addition, a beeper 15 and an indicator 17 are disposed on the housing 12 to indicate when the vehicle is ready for emissions testing. The interface 22 can be any interface that interfaces with a vehicle, including a Data Link Connector (DLC), such as, for example, an SAE J1962 connector.
FIG. 2 is a plan view of a non-cabled tool 24 according to another embodiment of the invention. The non-cabled tool 24 has a housing 26 with a display 14 . The housing 26 has an opening 30 for affixing the connector 22 that couples to a vehicle's onboard computer (not shown). Like tool 10 , tool 24 also has the beeper 15 , indicator 17 , and the display 14 disposed on the housing 26 . The non-cabled embodiment provides a compact device for a true one-piece device and compact storage. This embodiment can also be cheaper to produce due to decreased expense of not having a cable. Although both the beeper 15 and the indicator 17 are illustrated, only one or both may be used by the tool 10 or 24 and still be within the spirit of the present invention.
Internally, the tools 10 and 24 include a processor, memory, random access memory (RAM), communication circuitry and a power supply. The processor is configured with software enabling it to determine from the OBD II system whether the appropriate Drive Cycle has been completed and whether the monitors are set to “Ready” in order to perform the emissions test.
FIG. 3 is a schematic illustration of the tools 10 and 24 of FIGS. 1 and 2 . In particular, the tools 10 and 24 have a microcontroller or processor 40 . The processor 40 is coupled to a vehicle diagnostic connector 42 , a USB (Universal Serial Bus) connector 44 , and an RS232 connector 46 . In an alternative embodiment, the processor 40 can be a Field Programmable Gate Array (FPGA) or any other type of processor or controller.
The processor 40 is coupled to the vehicle diagnostic connector 42 through an SAE J1850 vehicle interface 52 , a CAN (Controlled Area Network) vehicle interface 54 and an ISO 9141-2 vehicle interface 56 . The processor is coupled to the ISO 9141-2 vehicle interface 56 by way of a multiplexer 62 . The J1850 vehicle interface 52 includes the hardware and/or software that allow the processor 40 to communicate with a vehicle equipped with J1850 communication protocol. The CAN vehicle interface 54 includes the hardware and/or software that allow the processor to communicate with a vehicle equipped with CAN communication protocol. Additionally, the ISO 9141-2 vehicle interface includes the hardware and/or, software that allow the processor 40 to communicate with a vehicle equipped with ISO 9141-2 communication protocol. A person skilled in the art will recognize that other vehicle communication protocols may also be utilized and that their respective interfaces are well within the embodiments of this invention.
The processor 40 couples to the USB connector 44 using a USB interface 58 and couples to the RS232 connector 46 through an RS232 interface 60 . The processor 40 couples to the USB interface 58 and the RS232 interface 60 via the multiplexer 62 . The USB connector 44 allows the tool to communicate with another computing device, such as a computer, Personal Digital Assistant (PDA) or a scan tool, while the RS232 can be used to communicate with other communication equipment, including computing devices. The processor also couples with a display driver 41 to drive the display 14 .
Further, a power supply 48 powers the processor 40 and the tool 10 or 24 . The power supply 48 may be provided by the VUT or another power source, such as a battery (external or internal to the housing). The processor 40 is coupled to the power supply 48 through a voltage detection device 50 . The voltage detection device 50 detects whether operating the full circuitry of the tool and/or charging the tool's internal battery, risks significantly discharging the vehicle's battery. When the vehicle's battery would be significantly drained by operating the full circuitry of the tool, the tool 10 or 24 is powered down and only the low-power voltage detection circuitry is operational. The processor 40 is also coupled to the beeper 15 and indicator 17 (discussed in greater detail below).
A device that uses power provided by the vehicle may drain the vehicle's battery unless the device is powered off when the vehicle engine is not running. In an embodiment of the present invention, tool 10 or 24 may be left coupled to the vehicle's computer even when the vehicle engine is not running without draining the vehicle's battery. The voltage detection device 50 may have a predetermined threshold of voltage for powering on, such as, for example 12.7 volts, the voltage of a fully charged battery. When the vehicle engine is started, the charging system may apply approximately 13.5 volts to the battery. This voltage keeps the battery fully charged and sometimes in an over charged state.
The voltage detection device 50 detects when the battery voltage is greater than 12.7 volts, the detection threshold, and the tool 10 or 24 powers on. It stays on while the vehicle engine is running and therefore, is powered by the vehicle charging system or the vehicle's battery. When the engine is turned off, the battery voltage will be approximately 13.5 volts. However, the voltage begins to decrease to the fully charged voltage of approximately 12.7 volts. While the battery's voltage decreases, the tool 10 or 24 is still powered on and receives power from the vehicle's battery. The time required for the decrease in voltage from 13.5 to 12.7 volts depends on various factors such as the strength of the battery, how long the vehicle was running, the battery temperature, etc. Time durations for this transition may be between approximately one to thirty minutes.
When the voltage reaches the detection threshold, the tool 10 or 24 powers off. Incidentally, the power drawn by the voltage detection device 50 may be negligible and does not discharge the vehicle battery. Thus, the tool 10 or 24 is powered on when the vehicle engine is (or has recently been) running and is powered off when the vehicle's engine is not (or has not recently been) running. However, in other embodiments of the invention, the tool 10 or 24 remains powered on for a certain amount of time after the vehicle powers off, so that the user can inspect the indicators 15 or 17 to ascertain whether the vehicle is “Ready.”
In the event that the vehicle battery is weak and the time for the vehicle's battery to return to the fully charged state from the over charged state, is short, the tool 10 or 24 may be configured to remain powered on for a particular period of time beyond the time the vehicle powers off. For example, the tool 10 or 24 may remain powered on for approximately two minutes. This permits the operator to inspect the tool 10 or 24 even though the vehicle has powered off. Further, this time delay embodiment also does not significantly discharge the vehicle battery.
Thus, the tool 10 or 24 may also be plugged into the vehicle even when the vehicle's engine is not running without discharging the vehicle battery. The tool 10 or 24 is capable of turning on only when there is no risk of battery drain. When there is a risk of battery drain, the tool enters the stand-by mode where it requires very little or no power. When the tool 10 or 24 is operating, it draws its power from the vehicle's battery and/or charging system. Alternatively, the tool 10 or 24 may be powered by another source internal or external to the housing, such as the tool's own battery.
In a further embodiment of the present invention, the processor 40 may also be coupled to a wireless communication device 59 which may communicate with a server 61 . In this manner, the processor 40 may communicate with a remote indicator that the vehicle is “Ready” for emissions testing. Thus, the server 61 may be used to send an email, text message or the like to any computing device, such as a PDA, PC, pager or cellular telephone indicating, for example, that the vehicle is ready for emissions testing. The server, which is a computing device, can itself indicate that the vehicle is ready for emissions testing via the methods described herein. The wireless communication device 59 and processor 40 may also communicate directly with another computing device, such as a PDA, PC, pager, or cellular telephone without first going through the server 41 . Additionally, software updates, reprogramming, and functional aspects of the tool can be controlled via the wireless communication.
OBDII devices have the ability to communicate with the vehicle using one of the many different vehicle communication protocols that may exist in the vehicle's control system. Although, it should be transparent to the technician, not all devices communicate with all vehicles. Thus, a technician must own several different scan tools to perform engine performance diagnostics on a variety of vehicle makes. This can be an expensive endeavor. In this embodiment, all communication protocols can be utilized with the tool to communicate with the vehicle.
The tools 10 and 24 may be reprogrammed or configured by a technician using a computing device such as a personal computer, PDA or a scan tool with configuration software. For instance, if the technician wants to check the status of only a few of the 11 diagnostic monitors, the technician can configure the tool 10 or 24 to do so. New or additional information can be uploaded to the tool 10 or 24 in a similar fashion. The tool 10 or 24 simply needs to be connected to a computing device, such as a personal computer (PC), PDA or scan tool using a Universal Serial Bus (USB) interface 58 , a RS232 serial interface 60 , a wireless communication or an infrared connection. Any means of connecting the tool may be used including wireless and wired connections or other communication protocols are within the spirit of the invention.
FIG. 4 is a flowchart illustrating steps in accordance with one embodiment of the method of the present invention. The vehicle fails the I/M testing and DTCs are found at step 64 . When the vehicle fails, the vehicle is taken to the repair facility at step 66 and the repair facility attempts to repair the vehicle at step 68 . The DTCs are erased, which also set the readiness state of all of the diagnostic monitors to “Not Ready.” The repair facility may be located at the same place as where the emission test is conducted. The facility then provides the vehicle operator with a readiness monitor tool 10 or 24 at step 70 . The vehicle operator uses the tool 10 or 24 and periodically checks the “Ready” status at step 72 to determine if the vehicle has completed its Drive Cycle and whether the monitors are “Ready.” If the necessary monitors are not ready, then proceed to step 77 and return to step 72 where the operator periodically checks until the monitors are ready. The tool can also periodically query the monitors at certain time intervals to determine if the monitors are “Ready.”
If it is determined that all the necessary monitors are ready at step 76 , the tool then determines it has wireless communication capabilities at step 78 . If the tool has wireless communication capabilities, the tool sends a burst of data to the server 61 via the wireless communication device 59 at step 80 . The repair facility then receives a notification, such as an email or other type of notification that the vehicle is ready for inspection at step 82 . The repair facility then contacts the vehicle operator to return the vehicle and the tool at step 84 . The operator then returns the tool and schedules an I/M retest at step 90 .
After the tool determines whether all the necessary monitors are ready, if the tool does not include wireless communication at step 78 , the tool then notifies the vehicle operator through an audio and/or visual indicator at step 86 via the beeper 15 or indicator 17 that the vehicle is ready for emissions testing. Upon being notified, the vehicle operator returns to the facility at step 88 and returns the tool and schedules an I/M retest at step 90 ending the process. Alternatively, the tool can provide wireless notification and notifies the operator through audio and/or visual indications on another device.
FIG. 5 is another flowchart illustrating steps in accordance with one embodiment of the method of the present invention. During the period where the operator periodically checks the status at step 72 , the vehicle operator plugs the tool into the diagnostic link connector at step 92 and starts the vehicle at step 94 . The tool then initiates communication with the vehicle at step 96 . If the tool has not initiated communication successfully at step 98 with the vehicle, the display indicates that the tool is still attempting to communicate with the vehicle at step 100 and returns to step 96 . Once the communication is successful, the tool queries the vehicle's onboard computer to determine whether the vehicle is ready at step 102 . If it is ready, then the tool 10 or 24 will proceed to step 76 via step 74 .
FIG. 6 is a flow chart illustrating the software program 102 residing in the processor 40 . At step 104 , when the tool is operational or on, the tool queries to see if a host computer is present. The host may be any computing device, such as, for example, a PC, a PDA or a scan tool that can be used to configure the tool. If host communication is present, the tool proceeds to communicate with the host to receive information, such as configuration data, updates or a new program at step 106 . This may be new updates, for example, from an automobile manufacturer or software needed to communicate in a different communication protocol. Additionally, the tool can be configured to ignore certain readiness monitors that are always “off” due to certain conditions, such as environmental conditions that may never exist regardless of how many Drive Cycles are completed. Once the tool has been configured, the process ends at step 108 . At this point, the user can power off the tool or unhook the tool from the host. The tool can then return to step 104 .
However, if the tool determines that it is not communicating with the host, then it initiates communication with the vehicle's computer to determine the status of I/M monitors at step 110 , then it proceeds to step 112 to determine whether the monitor status criteria has been met. If the criteria has not been met, the tool proceeds to step 114 where it indicates to the vehicle operator to “continue driving” on the display.
The “continue driving” indication may also be in the form of the beeper 15 or, for example, a light on the indicator 17 , such as a red light. Also, this indication may be in the form of an in-action, in that there is no audible or visual indication through beeper 15 or indicator 17 in the event the criteria are not met and the vehicle operator has to continue driving. The tool then proceeds to 110 where it continues to communicate with the vehicle to determine the status of the I/M monitors and proceeds to step 112 .
If the criteria has been met, the tool indicates to the vehicle operator that it is time to “return to the shop” at step 116 . This indication may be had by way of, for example, an audible sound on the beeper 15 or a green light, or another type of visual indication on the indicator 17 . Then the process ends at step 118 . The “return to shop” signal may also be displayed alphanumerically on the display.
Although various configurations are possible, in an embodiment of the present invention, the beeper 15 may be a piezo-electric beeper having a variety of beeping mechanisms. The length and timing of beeps may be adjusted as desired. The indicator 17 may be a LED display or a plurality of LED displays. These LED indicators may flash on, turn off or held on continuously to indicate when the vehicle is “Ready” or “Not Ready.”
The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | An OBDII device method and system includes an inexpensive, user friendly way to determine a vehicle's readiness for emissions testing and if repairs were successful. An audible and/or visual indicator is provided to alert the repair shop technician or driver that the vehicle has completed its drive cycle and may now be tested for compliance with state and federal emissions laws or indicate that the emissions related repairs were successful. | 6 |
TECHNICAL FIELD
[0001] The invention relates to the detection of a biomarker in a biological sample to test for the presence of prostate cancer. Specifically, the invention relates to the detection of a plurality of biomarkers in a biological sample to distinguish the presence of aggressive prostate cancer from non-aggressive prostate cancer or no cancer.
BACKGROUND TO THE INVENTION
[0002] Prostate cancer (PCa) is the most common non-cutaneous malignancy in men in the Western world. An estimated 1.1 million new cases were diagnosed in 2012, accounting for 15% of all male cancers worldwide. Ireland is currently experiencing one of the highest incidences of PCa in Europe, with approximately 3,000 new cases diagnosed per annum, representing 30% of all invasive cancers in men. With an ageing Western population and spread of Western culture (particularly diet), the global incidence is predicted to rise dramatically; the National Cancer Registry predicts the incidence in Ireland to rise by between 104-288% by 2040.
[0003] It is often said that “most men die with and not because of their prostate cancer”. This is explained by the fact that most prostate tumours have a slow, long natural trajectory, posing little likelihood of clinical manifestation, and deemed indolent in nature; 10-year survival rates for PCa are close to 100%. Nevertheless, a proportion of prostate tumours are highly aggressive, and are associated with the lethal form of the disease. Whilst PSA (prostate specific antigen) screening and improvements in treatments have reduced PCa mortality, this disease accounted for an ˜307,000 deaths in 2012, making it the 5 th leading cause of male cancer-related deaths worldwide. Identifying molecular correlates to discern between aggressive and indolent tumors at an early stage (whilst potentially curable), is one of the greatest unmet clinical needs in this field. This will become even more pressing as the differential between the total number of PCa cases diagnosed and the number of lethal PCa cases grows.
[0004] Early detection and diagnosis of PCa involves a combination of a PSA blood test, a digital rectal examination (DRE) and histological examination of transrectal ultrasound (TRUS)-guided biopsy cores, respectively. Several major problems confound the early detection of PCa. There are an estimated 25-45 million PSA tests performed worldwide every year, Widespread PSA testing has significantly increased PCa incidence and led to overtreatment of low-risk disease with little likelihood of clinical manifestation. A further problem with PSA is its poor tumour-specificity; its high false-positive rate means that two-thirds of men who undergo invasive TRUS-biopsy have no tumour diagnosed. There are an estimated 10 million prostate biopsies performed worldwide/annum. Unnecessary TRUS-biopsies create an enormous burden on our healthcare system and cause significant anxiety, trauma and co-morbidities for patients. Finally, TRUS-biopsies are needle biopsies that sample <5% of the prostate and can thus miss tumour foci or indeed miss high-grade aggressive tumours. Studies addressing the economic burden of cancer in the EU, have estimated costs for PCa diagnosis and treatment over the next 20 years per 100,000 men at 30,284,000 (unscreened population) and 60,695,000 (screened population), 23,669,000 of which can be attributed to over-detected cancers.
[0005] Currently, there are no commercially available molecular diagnostics for PCa in widespread clinical practice. Progensa® (Gen-Probe) is a urine-based test of PCA3 gene expression performed after DRE, with FDA approval for use in men who have had ≧1 previous negative biopsies and for whom a repeat biopsy would be recommended based on current standard of care. The test is used to guide the decision to perform a repeat biopsy only. Its prognostic value is debated and research efforts combining it with the fusion-transcript TMPRSS2-ERG are underway in an attempt to address this.
[0006] Prolaris® (Myriad Genetics) and oncotypeDX® Prostate Cancer Assay (Genomic Health) are two examples of prognostic gene expression signatures (46 genes and 17 genes, respectively) that are analysed on biopsy tissues to aid prediction of PCa aggressiveness in conjunction with other clinical parameters (Gleason score, PSA). Both tests provide a more individualised risk-assessment of the underlying biology of the patient's tumour and are therefore aimed at guiding the decision between active surveillance and radical treatment in men diagnosed with PCa.
[0007] MDxHealth's product ConfirmMDx™ is a PCR-based assay, which measures methylation of a 3-gene panel (GSTP1, RARβ, APC) in biopsy cores. It is positioned to distinguish patients with a true-negative prostate biopsy from those with occult cancer and akin to Progensa®, is used to guide the decision to perform a repeat biopsy. This same 3-gene panel (ProCaM™) has also been investigated as a urine test to predict biopsy results for PCa, although these studies were inadequately powered.
[0008] It is an object of the subject invention to overcome at least one of the above-mentioned problems.
STATEMENTS OF INVENTION
[0009] In contrast to these prior art technologies, the test presented herein (called epigenetic Cancer of the Prostate test in urine or epiCaPture) is an example of a “first in field” for urine diagnostics of potentially lethal, high-risk PCa. The panel of genes encompasses multiple dysregulated pathways in PCa, which is necessary to address the heterogeneity of the disease. These pathways include intracellular detoxification, the IGF axis, the Wnt axis and inflammation. The test presented herein addresses the unmet clinical needs confounding early detection of PCa. The test is a non-invasive DNA methylation test performed using urine or urine cell-sediment. It comprises a panel of at least 6 genes and an internal control gene. The test described herein offers significant commercial potential as a liquid biopsy for early non-invasive detection of high-risk, potentially lethal PCa. The data show that the test offers the unique advantages of i) better tumour-specificity than PSA, and ii) selective identification of high-risk PCa.
[0010] According to the invention, there is provided, as set out in the appended claims, a method of determining the risk of aggressive prostate cancer in an individual diagnosed with prostate cancer, comprising a step of assaying a biological sample obtained from the individual for the presence of at least one methylated regulatory DNA sequence selected from group comprising SEQ ID NOs. to 1 to 16, or variants thereof, and correlating the presence of the at least one methylated regulatory DNA sequence with the risk of aggressive prostate cancer. The methylated regulatory DNA sequences as defined by SEQ ID NOs. 1 to 16 correspond to the genes GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6, respectively, and correlating the presence of the methylated regulatory DNA sequence(s) of these genes with an increased risk of aggressive prostate cancer. The presence of the methylated regulatory DNA sequence may be detected directly by quantitatively assaying for methylation of the DNA regulatory sequences located adjacent to the associated gene(s).
[0011] In one embodiment, the method further comprises the step of assaying for the presence of the PSA gene in addition to at least one methylated regulatory DNA sequence corresponding to the genes selected from group comprising GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6, wherein the presence of PSA in combination with positive detection of the at least one methylated regulatory DNA sequence corresponding to the genes selected from group comprising GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6, correlates with an increased risk of aggressive prostate cancer compared with an individual with prostate cancer who is positive for PSA detection but negative for detection of the at least one methylated regulatory DNA sequence.
[0012] In a preferred embodiment of the invention, the method involves assaying for methylation of a DNA regulatory sequence specific to the or each gene selected from group comprising GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6. Preferably, the DNA regulatory sequence is one or both of SEQ ID NOs 1 or 3, or variants thereof, which are specific to the biomarkers GSTP1 and IGFBP3, respectively. Specifically, the DNA regulatory sequence is one or more selected from SEQ ID NOs: 1 to 16, or variants thereof, and is specific to the biomarkers selected from GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6, respectively. Preferably, the DNA regulatory sequence assayed for is all of SEQ ID NOs: 1 to 16, or variants thereof, and are specific to the biomarkers GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6, respectively. Ideally, the DNA regulatory sequence assayed for is all of SEQ ID NOs: 1 to 6, or variants thereof, and are specific to the biomarkers GSTP1, SFRP2, IGFBP3, IGFBP7, APC, and PTGS-2, respectively. Preferably, assaying for methylation of the DNA regulatory sequence specific to the or each biomarker is combined with assaying for PSA (internal control, SEQ ID NO. 18).
[0013] In one embodiment, the method comprises assaying for at least four DNA regulatory sequence specific to their corresponding genes, at least three DNA regulatory sequences selected from the group comprising: SEQ ID NO.'s 1 to 16, or variants thereof, and at least one selected from the group comprising: SEQ ID NO.'s 17 and 18. Preferably, both SEQ ID NO. 17 and SEQ ID NO. 18 are determined in the method. In this way, the method of the invention employs at least three “positive” regulatory DNA sequences (i.e. a regulatory DNA sequence associated with presence of the cancer), and at least one “control” biomarker (i.e. a biomarker associated with prostate-derived DNA). Ideally, the “positive” regulatory DNA sequences are selected from the group comprising SEQUENCE ID NO's 1 to 6.
[0014] The two controls may be used in the method of the invention:
1) ACTB (SEQ ID NO. 17): ACTB is measured by quantitative PCR (qPCR) and verifies and quantifies the presence of bisulfite modified DNA in each test sample. The quantity of ACTB is used to calculate an epiCaPture score (a score derived from the method of the invention). The amount of each gene in the method must be normalised relative to the amount of input bisulfite modified DNA in each test sample. 2) KLK3 (SEQ ID NO. 18). Expression of the KLK3 gene (the gene encoding PSA, Prostate Specific Antigen) is measured by quantitative RT-PCR and is used as a positive control to confirm the presence of prostate-derived nucleic acids in the test sample. This is important to carry out, in order to show that a test sample which appears negative for prostate cancer as determined by the method of the invention, is indeed truly negative and it is not simply a virtue of no prostate-derived material present in the bio-specimen. The expression of the KLK3 gene is measured using a commercially available qPCR assay, such as Integrated DNA Technologies (Assay ID Hs.PT.58.38546086).
[0017] In one embodiment, the method comprises assaying a biological sample obtained from the individual for the presence of at least four methylated regulatory DNA sequence selected from group comprising SEQ ID NOs. to 1 to 16, or variants thereof, and correlating the presence or absence of the at least four methylated regulatory DNA sequence with the risk of aggressive prostate cancer.
[0018] In one embodiment, the method comprises assaying a biological sample obtained from the individual for the presence of at least four methylated regulatory DNA sequence selected from group comprising SEQ ID NOs. to 1 to 12 and 14, or variants thereof, and correlating the presence or absence of the at least four methylated regulatory DNA sequence with the risk of aggressive prostate cancer.
[0019] In one embodiment, the method comprises a step of assaying a biological sample obtained from the individual for the presence of a methylated regulatory DNA sequence from at least three sequences selected from group comprising: SEQUENCE ID NO's 1 to 16, or variants thereof, where the DNA regulatory sequences are specific to the biomarkers (genes) GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6. In a preferred embodiment, the method comprises a step of assaying a biological sample for three, four, five, or six regulatory DNA sequence selected from group comprising: SEQUENCE ID NO's 1 to 16, or a variant thereof, where the regulatory DNA sequences are specific to the biomarkers (genes) GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6. In a particularly preferred embodiment of the invention, the method comprises a step of assaying a biological sample obtained from the individual for the presence of a methylated regulatory DNA sequences defined by the group comprising, or consisting essentially of, SEQUENCE ID NO's 1 to 6, or variants thereof, where the regulatory DNA sequences are specific to the biomarkers (genes) GSTP1, SFRP2, IGFBP3, IGFBP7, APC and PTGS-2. Preferably, assaying for methylation of the regulatory DNA sequences, or variants thereof, where the regulatory DNA sequences are specific to the biomarkers (genes) GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, is combined with assaying for PSA.
[0020] Where a patient is found to be positive for the methylated regulatory DNA sequences of SEQ ID NOs 1 to 6, or variants thereof, this correlates with a positive identification of prostate cancer at 97.92% specificity and a false positive rate of 0.04 versus 21% specificity and a false positive rate of 0.79 using PSA detection (applying a threshold of 4 ng/ml).
[0021] Where a patient is found to be positive for all six of the methylated regulatory DNA sequences defined by SEQ ID NOs. 1 to 6, or variants thereof, this correlates with a positive identification of aggressive (high-risk) prostate cancer with a 79% sensitivity and an 82% specificity. The combination of the assay result of only two of these methylated regulatory DNA sequences, namely SEQ ID NO. 1 and SEQ ID NO. 3 (corresponding to the genes GSTP1 and IGFBP3, respectively) in this present analysis correlated with a positive detection of aggressive (high-risk or metastatic) prostate cancer with a sensitivity score of 82% and a specificity score of 82%.
[0022] In a preferred embodiment of the invention, the method comprises a step of assaying a biological sample from the individual for the presence of methylated regulatory DNA sequences defined by SEQ ID NO. 1 (GSTP1), and SEQ ID NO. 3 (IGFBP3), or variants thereof, optionally in combination with one or more methylated regulatory DNA sequences of genes selected from the group comprising: SEQ ID NO 2 (SFRP2), SEQ ID NO. 4 (IGFBP7), SEQ ID NO. 5 (APC), and SEQ ID NO. 6 (PTGS2), or variants thereof. The method may also comprise assaying a biological sample from the individual for the presence of methylated regulatory DNA sequences defined by SEQ ID NO. 1 (GSTP1), and SEQ ID NO. 3 (IGFBP3), or variants thereof, optionally in combination with one or more methylated regulatory DNA sequences of genes selected from the group comprising: SEQ ID NO 2 (SFRP2), SEQ ID NO. 4 (IGFBP7), SEQ ID NO. 5 (APC), SEQ ID NO. 6 (PTGS2), SEQ ID NO. 7 (LXN), SEQ ID NO. 8 (MAGPIE-1B), SEQ ID NO. 9 (DNAH10), SEQ ID NO. 10 (ZMIZ1), SEQ ID NO. 11 (CENPV), and SEQ ID NO. 12 (OR2L13), or variants thereof. The method may also comprise assaying a biological sample from the individual for the presence of methylated regulatory DNA sequences defined by SEQ ID NO. 1 (GSTP1), and SEQ ID NO. 3 (IGFBP3), or variants thereof, optionally in combination with one or more methylated regulatory DNA sequences of genes selected from the group comprising: SEQ ID NO 2 (SFRP2), SEQ ID NO. 4 (IGFBP7), SEQ ID NO. 5 (APC), and SEQ ID NO. 6 (PTGS2), SEQ ID NO. 7 (LXN), SEQ ID NO. 8 (MAGPIE-1B), SEQ ID NO. 9 (DNAH10), SEQ ID NO. 10 (ZMIZ1), SEQ ID NO. 11 (CENPV), and SEQ ID NO. 12 (OR2L13), SEQ ID NO. 13 (MTMR8), SEQ ID NO. 14 (F3), SEQ ID NO. 15 (CDH8), and SEQ ID NO. 16 (GALNTL6), or variants thereof.
[0023] The method may also comprise assaying a biological sample from the individual for the presence of methylated regulatory DNA sequences defined by SEQ ID NO. 1 (GSTP1), and SEQ ID NO. 3 (IGFBP3), or variants thereof, optionally in combination with one or more methylated regulatory DNA sequences of genes selected from the group comprising: SEQ ID NO 2 (SFRP2), SEQ ID NO. 4 (IGFBP7), SEQ ID NO. 5 (APC), and SEQ ID NO. 6 (PTGS2), SEQ ID NO. 7 (LXN), SEQ ID NO. 8 (MAGPIE-1B), SEQ ID NO. 9 (DNAH10), SEQ ID NO. 10 (ZMIZ1), SEQ ID NO. 11 (CENPV), and SEQ ID NO. 12 (OR2L13) and SEQ ID NO. 14 (F3), or variants thereof.
[0024] Preferably, the biological sample is assayed for the presence of PSA in combination with the methylated regulatory DNA sequences of any one or all of SEQUENCE ID NO's 1 to 6. Preferably, the biological sample is assayed for the presence of PSA in combination with the methylated regulatory DNA sequences of any one or all of SEQUENCE ID NO's 7 to 12. Preferably, the biological sample is assayed for the presence of PSA in combination with the methylated regulatory DNA sequences of any one or all of SEQUENCE ID NO's 7 to 12 and 14. Preferably, the biological sample is assayed for the presence of PSA in combination with the methylated regulatory DNA sequences of any one or all of SEQUENCE ID NO's 13 to 16.
[0025] The invention also relates to a kit for assessing prostate cancer status in an individual, comprising components for detecting and/or measuring the level of a methylated regulatory DNA sequence of at least three selected from the group comprising: SEQUENCE ID No's 1 to 6.
[0026] The kit preferably comprises a pair of forward and reverse oligonucleotide primers (SEQ ID NOs. 22 to 55) designed to specifically hybridise with bisulfite modified hypermethylated DNA sequences at the regulatory regions of each specific gene as defined by SEQ ID NOs 1 to 16; a fluorescently labelled oligonucleotide probe designed to specifically hybridise with bisulfite modified hypermethylated DNA sequences at the regulatory region of each specific gene (SEQ ID NO. 56 to 72), a set of forward and reverse oligonucleotide primers and a fluorescently labelled probe to specifically hybridise with bisulfite modified DNA contained as part of the human ACTB gene, regardless of DNA methylation patterns of this gene (Positive control 1), a qRT-PCR assay for the KLK3 gene (Positive control 2) to control for the presence of prostate-derived nucleic acids in the bio-specimen, and a gBlock® synthetic gene fragments for construction of standard curves (SEQ ID NO. 19, 20 or 21), necessary for quantification of methylation levels at individual DNA sequences contained within the panel.
[0027] As indicated above, the methods, assays and kits of the invention employ biomarkers (methylated regulatory DNA sequences of specific genes or oligonucleotides specific to those regulatory DNA sequences of those genes) as a means of assessing the risk of an aggressive or metastatic prostate cancer in an individual. In one preferred embodiment of the invention, the methods, assays, and kits may be employed as a clinical screening tool to assist in the identification of individuals with an aggressive form of or a high risk metastatic prostate cancer, especially symptomatic individuals, who should be subjected to more invasive investigations, such as a prostate biopsy. In this regard, it should be noted that many patients who present with symptoms of prostate cancer (i.e. the need to urinate frequently, difficulty in starting urination, weak or interrupted flow of urine, painful/burning urination; blood in the urine etc.) can turn out to be negative for prostate cancer, yet still have to undergo a prostate biopsy to reach that diagnosis. In this regard, the present invention provides a useful clinical decision making tool which can assist a clinician in identifying those symptomatic patients that are most at risk of having the cancer, thereby potentially reducing the numbers of patients who have to undergo a prostate biopsy needlessly.
[0028] Thus, in one embodiment, the invention relates to a method of determining prostate cancer status in an individual, the method comprising a step of assaying a biological sample from the individual for a combination of methylated DNA regulatory sequences selected from SEQUENCE ID NO's: 1 to 16, which are the DNA regulatory sequences GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV, OR2L13, MTMR8, F3, CDH8 and GALNTL6, respectively, the combination of methylated DNA regulatory sequences being chosen such that detection of at least one or more of the methylated DNA regulatory sequences in the individual correlates to at least a 50% risk of the individual being positive for aggressive or high risk metastatic prostate cancer. Typically, the combination of methylated DNA regulatory sequences is chosen such that detection of at least one or more of the methylated DNA regulatory sequences in the individual correlates to at least a 60% risk of the individual being positive for aggressive or high risk metastatic prostate cancer. Suitably, the combination of methylated DNA regulatory sequences is chosen such that detection of one or more of the methylated DNA regulatory sequences in the individual correlates to at least a 70% risk of the individual being positive for aggressive or high risk metastatic prostate cancer. Ideally, the combination of methylated DNA regulatory sequences is chosen such that detection of one or more of the methylated DNA regulatory sequences in the individual correlates to at least an 80% risk of the individual being positive for aggressive or high risk metastatic prostate cancer. Preferably, the detection of one or more methylated DNA regulatory sequences are combined with PSA.
[0029] Typically, the combination will comprise at least one methylated DNA regulatory sequences, at least two methylated DNA regulatory sequences, at least three methylated DNA regulatory sequences, preferably at least four methylated DNA regulatory sequences, more preferable would be at least five methylated DNA regulatory sequences, more preferably still at least six methylated DNA regulatory sequences, and ideally between at least seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, or sixteen methylated DNA regulatory sequences. Preferably, the at least one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, or sixteen methylated DNA regulatory sequences selected are combined with PSA. Preferably, the methylated DNA regulatory sequences are selected from SEQUENCE ID NO's: 1 to 16, or SEQ ID NO's 1 to 12 and 14.
[0030] Typically, the biological fluid is urine, or a derivative of urine following centrifugation or filtration, such as urine cell sediment.
[0031] In one aspect of the invention, there is provided, as set out in the appended claims, a method of determining the risk of aggressive prostate cancer in an individual diagnosed with prostate cancer, the method comprising a step of assaying a biological sample obtained from the individual for the presence of at last one methylated regulatory DNA sequence selected from group comprising: SEQ ID No's 1 to 16, or variants thereof, and correlating the presence or absence of the methylated regulatory DNA sequence with aggressive prostate cancer.
[0032] In one embodiment, detection of least three methylated regulatory DNA sequence from the group comprising SEQ ID NOs 1 to 16, or variants thereof, correlates with the presence of an aggressive prostate cancer.
[0033] In one embodiment, detection of least four, five or six methylated regulatory DNA sequence from the group comprising SEQ ID NOs 1 to 16, or variants thereof, correlates with the presence of aggressive prostate cancer.
[0034] Preferably, detection of six methylated regulatory DNA sequences as defined by SEQ ID NOs 1 to 6, or variants thereof, and having a sensitivity of at least 80% correlates with the presence of an aggressive prostate cancer.
[0035] In one embodiment, the method further comprises detecting the presence of PSA in the biological sample.
[0036] In one embodiment, the sample is urine or a urine derivative from the individual.
[0037] In one embodiment, there is provided an assay of identifying an aggressive prostate cancer in an individual, the assay comprising the step of assaying a biological sample obtained from the individual for the presence of a methylated regulatory DNA sequence selected from group comprising: SEQ ID No's 1 to 16, or variants thereof, and at least one sequence selected from SEQ ID NOs 17 and 18, wherein detection of at least three of the methylated regulatory DNA sequences from SEQ ID NOs 1 to 16, or variants thereof, and one sequence from SEQ ID NOs 17 and 18 in a sample is indicative of the presence of an aggressive prostate cancer, and wherein the sensitivity of the assay for detecting the at least three methylated regulatory DNA sequences from SEQ ID NOs 1 to 16, or variants thereof, is at least 80%.
[0038] In one embodiment, detecting at least six methylated DNA regulatory sequences as defined by SEQ ID NOs 1 to 12 and 14 correlates with the presence of an aggressive prostate cancer, at high-risk of metastasising. Preferably, detecting at least six methylated DNA regulatory sequences as defined by SEQ ID NOs 1 to 12 and 14, and having a sensitivity of at least 80%, correlates with the presence of an aggressive prostate cancer.
[0039] In one embodiment, the at least one sequence selected from SEQ ID NOs 17 and 18 is SEQ ID NO: 18, prostate-specific antigen (PSA).
[0040] Preferably, detection of at least six methylated DNA regulatory sequences as defined by SEQ ID NOs 1 to 6, or variants thereof, and having a sensitivity of at least 80% correlates with the presence of an aggressive prostate cancer.
[0041] In one embodiment, there is provided a kit for detecting the presence of prostate cancer in a sample from an individual, the kit comprising a control oligonucleotide as defined by SEQ ID NO 19, 20 or 21, or a variant thereof, and a set of oligonucleotides for detecting SEQ ID NOs 1 to 16, or variants thereof, wherein detection of at least three sequences from SEQ ID NOs 1 to 16, or variants thereof, in the sample is indicative of the presence of prostate cancer, and wherein the sensitivity of the assay for detecting the at least three sequences from SEQ ID NOs 1 to 16, or variants thereof, is at least 80%.
[0042] In one embodiment, the prostate cancer is an aggressive prostate cancer.
[0043] In one embodiment, the kit further comprises an oligonucleotide for detecting the presence of PSA.
[0044] In one embodiment, the set of oligonucleotides is defined by SEQ ID NOs. 22 to 72.
[0045] In one embodiment, the kit further comprises a support having at least one oligonucleotide selected from group SEQ ID No's 1 to 16 anchored thereon.
[0046] In one embodiment, the kit comprises a support having three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, or sixteen oligonucleotides anchored thereon selected from SEQ ID NOs. 1 to 16.
[0047] In one embodiment, the kit comprises a support having three, four, five, six, seven, eight, nine, ten, eleven, twelve or thirteen oligonucleotides anchored thereon selected from SEQ ID NOs. 1 to 12 and 14.
[0048] In one aspect of the invention, there is provided, as set out in the appended claims, a method of determining the risk of aggressive prostate cancer in an individual, the method comprising a step of assaying a biological sample obtained from the individual for the presence of at last one methylated regulatory DNA sequence selected from group comprising: SEQ ID No's 1 to 16, or variants thereof, and correlating the presence or absence of the methylated regulatory DNA sequence with aggressive prostate cancer.
[0049] In one embodiment, detection of least three methylated regulatory DNA sequence from the group comprising SEQ ID NOs 1 to 16, or variants thereof, correlates with the presence of an aggressive prostate cancer.
[0050] Preferably, detection of SEQ ID NO. 1 and SEQ ID NO. 3, or variants thereof, together with at least one further sequence selected from SEQ ID NOs. 2, 4, 5 and 6, or variants thereof, correlates with the presence of an aggressive prostate cancer.
[0051] In one embodiment, detection of least four, five or six methylated regulatory DNA sequence from the group comprising SEQ ID NOs 1 to 16, or variants thereof, correlates with the presence of aggressive prostate cancer.
[0052] Preferably, detection of six methylated regulatory DNA sequences as defined by SEQ ID NOs 1 to 6, or variants thereof, and having a sensitivity of at least 80% correlates with the presence of an aggressive prostate cancer.
[0053] In one aspect of the invention, there is provided, as set out in the appended claims, a method of detecting the presence of prostate cancer in an individual, the method comprising a step of assaying a biological sample obtained from the individual for the presence of at last one methylated regulatory DNA sequence selected from group comprising: SEQ ID No's 1 to 16, or variants thereof, and correlating the presence or absence of the methylated regulatory DNA sequence with a reference abundance marker indicative of prostate cancer.
[0054] In one aspect of the invention, there is provided, as set out in the appended claims, a method of determining whether an individual requires an invasive trans-rectal biopsy to confirm diagnosis of prostate cancer by histological review of a biopsy specimen, the method comprising a step of assaying a biological sample obtained from the individual for the presence of at last one methylated regulatory DNA sequence selected from group comprising: SEQ ID No's 1 to 16, or variants thereof, and in which the presence of the methylated regulatory DNA sequence determines that the individual requires an invasive trans-rectal biopsy to confirm diagnosis of prostate cancer by histological review of a biopsy specimen.
[0055] In one embodiment, the biological sample is urine or a urine derivative from the individual.
[0056] In one embodiment, the method comprises detection of six methylated regulatory DNA sequences as defined by SEQ ID NOs 1 to 12 and 14 correlates with the presence of an aggressive prostate cancer. Preferably, detection of six methylated regulatory DNA sequences as defined by SEQ ID NOs 1 to 12 and 14, and having a sensitivity of at least 80%, correlates with the presence of an aggressive prostate cancer.
[0057] In one embodiment, the assay comprises detection of six methylated regulatory DNA sequences as defined by SEQ ID NOs 1 to 12 and 14, and having a sensitivity of at least 80%, correlates with the presence of an aggressive prostate cancer.
[0058] In one embodiment, the methods and assays described above further comprise the step of applying a NIM threshold of 0.73 for discriminating biopsy positive from biopsy negative samples. In one embodiment, the methods and assays described above further comprise the step of applying a NIM threshold of 1.25 for detecting high-risk or high grade (aggressive) prostate cancer from the samples being assayed. The NIM equation normalises for the amount if input bisulfite modified DNA present in the sample and calculates the proportion of the target sequence which is methylated relative to a 100% fully methylated DNA sequence.
[0059] In this specification, the term “biological sample” or “biological fluid” may be a sample obtained from an individual such as, for example, urine or urine cell-sediment, blood or a prostate tissue sample from a biopsy or a radical prostatectomy. In many cases, the individual will be a person suspected of having prostate cancer, or pre-disposed to developing prostate cancer as determined by other phenotypic, genotypic or hereditary traits.
[0060] In this specification, the term “prostate cancer status” when used with reference to an individual primarily refers to the risk of the individual having the cancer. Depending on the number of biomarkers detected in the individual, the assay and methods of the invention will assist a clinician is determining the risk that the individual is positive for prostate cancer. Thus, in one embodiment, the methods, assays and kits of the invention provide a means for screening male patients to identify those patients that should undergo further investigative procedures, such as a biopsy. However, the term also encompasses prognostic evaluation of the cancer, identification of predisposition to developing the cancer, staging of the cancer, and evaluation or monitoring of the progress of the cancer, in the individual. The latter evaluation is typically employed as a means of monitoring the effectiveness of a treatment for the cancer.
[0061] A “variant” of one of SEQUENCE ID No's 1 to 16 shall be taken to mean at least 70% sequence identity, preferably at least 80% sequence identity, more preferably at least 90% sequence identity, and ideally at least 95%, 96%, 97%, 98% or 99% sequence identity with the native sequence.
[0062] mRNA expression of the KLK3 gene (positive control 2—SEQ ID NO. 18) may be measured by any suitable method including, but not limited to, a Northern Blot or detection by hybridisation to a oligonucleotide probe. A variety of hybridization assays using a variety of technologies for hybridization and detection are available. For example, a TaqMan assay (PE Biosystems, Foster City, Calif.; See e.g., U.S. Pat. Nos. 5,962,233 and 5,538,848,) is utilized. The assay is performed during a PCR reaction. The TaqMan assay exploits the 5′-3′ exonuclease activity of the AMPLITAQ GOLD DNA polymerase. A probe consisting of an oligonucleotide with a 5′-reporter dye (e.g., a fluorescent dye) and a 3′-quencher dye is included in the PCR reaction. During PCR, if the probe is bound to its target, the 5′-3′ nucleolytic activity of the AMPLITAQ GOLD polymerase cleaves the probe between the reporter and the quencher dye. The separation of the reporter dye from the quencher dye results in an increase of fluorescence. The signal accumulates with each cycle of PCR and can be monitored with a fluorometer.
[0063] DNA methylation may be measured by any suitable method, such as quantitative methylation specific PCR (PMID: 10734209).
[0064] In other embodiments, reverse-transcriptase PCR (RT-PCR) is used to detect the expression of RNA where RNA is enzymatically converted to complementary DNA or “cDNA” using a reverse transcriptase enzyme. The cDNA is then used as a template for a PCR reaction. PCR products can be detected by any suitable method, including but not limited to, gel electrophoresis and staining with a DNA specific stain or hybridization to a labelled probe. In some embodiments, the quantitative reverse transcriptase PCR with standardized mixtures of competitive templates method described in U.S. Pat. Nos. 5,639,606, 5,643,765, and 5,876,978 is utilized.
[0065] In the specification, the term “high-risk prostate cancer”, “high-risk disease” or “aggressive prostate cancer” or “metastatic prostate cancer” should be understood mean a prostate cancer that is categorised by the D'Amico Risk Stratification criteria. The D'Amico criteria are used to define low, intermediate and high-risk prostate cancer. For example, (i) Low risk: having a PSA less than or equal to 10, a Gleason score less than or equal to 6, or are in clinical stage T1-2a; (ii) Intermediate risk: having a PSA between 10 and 20, a Gleason score of 7, or are in clinical stage T2b; and (iii) High-risk: having a PSA more than 20, a Gleason score equal or larger than 8, or are in clinical stage T2c-3a. The terms high-risk, aggressive and metastatic can be used interchangeably. The terms high-risk and aggressive describe a cancer of high tumour grade (according to the Gleason scale, >=8) and a highly likelihood of metastasising.
[0066] In the specification, the term “gBlock®” should be understood to mean a double-stranded DNA molecule of 125-2000 bp in length. In this instance, the gBlock® is defined by SEQ ID NO. 19 and contains sequences for (A) an internal control ACTB, and the genes (B) GSTP1 (C), SFRP2, (D) IGFBP3, (E) IGFBP7, (F) APC and (G) PTGS2. The gBock® defined by SEQ ID NO: 20 was designed to contain the nucleotide sequences of bisulfite converted fully methylated internal control sequence (ACTB) and seven DNA regulatory sequences (LXN, MAGPIE-1B, DNAH10, ZMIZ1, CENPV and OR2L13). The gBlock® defined by SEQ ID NO. 21 was designed to contain the nucleotide sequences of bisulfite converted fully methylated internal control sequence (ACTB) and four DNA regulatory sequences (MTMR8, F3, CDH8 and GALNTL6).
[0067] Some of the uses of the invention include:
To test for the presence of prostate cancer. Use as a novel screening test for any male at risk of having prostate cancer. Use as a non-invasive test using urine to determine which male requires an invasive trans-rectal biopsy to confirm a diagnosis of prostate cancer by histological review of a biopsy specimen. The test can be carried out on any biological sample that harbours prostate DNA, including blood plasma/serum, prostate tissue and metastatic lesions, either visceral or bone.
[0072] Some of the advantages of the invention is to:
Reduce/eliminate unnecessary invasive biopsies in men who don't need them; Identify which men require a trans-rectal prostate biopsy Alleviate over-treatment of low-risk disease; Inform the clinician about the molecular biology of the disease; and Aid risk-stratification for selection of subsequent treatments/active surveillance.
BRIEF DESCRIPTION OF THE FIGURES
[0078] The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which:—
[0079] FIG. 1 illustrates Feasibility Study data (n=156). Results on a panel of 156 pre-biopsy urine samples, shown by biopsy outcome. Positive-biopsy men are further categorised into low (LR), intermediate (IR) and high (HR) risk groups using the CAPRA score. Each row represents a gene, each column represents a patient. Methylation is measured as a continuous variable from 0-1000 (Normalised Index of Methylation, NIM). Black squares indicate high methylation with a normalised index of methylation (NIM)>1, white squares indicate NIM=0 and shades of grey indicate intermediate NIM.
[0080] FIG. 2 illustrates results reduced into categorical results: men with methylation of at least one gene and men with an NIM>1 in any one gene.
[0081] FIG. 3 illustrates ROC curves for (A) PSA alone, (B)-(C) using the invention, and (D) the test of the invention and PSA>4 ng/ml, which achieve an AUC of 0.54, 0.87 (average) and 0.96, respectively.
[0082] FIG. 4 illustrates that the positive predictive value of invention which indicates its utility for reducing number of unnecessary biopsies by selectively detecting aggressive PCa.
[0083] FIG. 5 illustrates standard curves constructed over a 6-log range using 5 independent qMSP measurements of a gBlock® fragment containing sequences for (A) internal control, (B) GSTP1 (C), SFRP2, (D) IGFBP3, (E) IGFBP7, (F) APC and (G) PTGS2 (SEQ ID NO. 19). Each qMSP assay has a slope of −3.3 (+/−10%) and an R 2 >0.99, indicating a PCR efficiency close to 100%.
[0084] FIG. 6 illustrates graphs showing quantitative methylation-specific PCR data for SEQ ID NOs 7-16 in a radical prostatectomy cohort reveal quantitatively higher levels of DNA methylation in aggressive tumours (PC-A) compared with significant (PC-S) and indolent (PC-I) tumours and benign tissue.
[0085] FIG. 7 illustrates graphs showing descriptive statistics of the study cohort used in epiCaPture analysis with an increased cohort size from 156 men to 283 men. The data presented includes the original cohort of patients. A) Age, B) PSA levels of men (Whiskers indicate the minimum and maximum levels and the mean is indicated by a horizontal line) and statistics of the biopsy-positive cohort used in epiCaPture analysis. Patients were stratified according to C) D'Amico risk group and D) tumour grade (Gleason score, GS).
[0086] FIG. 8 illustrates a heat map of epiCaPture NIM scores for increased cohort of 283 men. Positive-biopsy men are further categorised by Gleason score. Each row represents a gene, each column represents a patient. Methylation is measured as a continuous variable from 0-1000 (Normalised Index of Methylation, NIM). White squares represents absence of methylation (NIM=0), with increasing shades of grey and black representing quantitatively higher amounts of methylation for a gene.
[0087] FIG. 9 is a graph illustrating performance of epiCaPture versus predicate at non-invasive detection of high-risk prostate cancer.
[0088] FIG. 10 are graphs illustrating GSTP1 methylation as detected in three independent cohorts of radical prostatectomy samples (A) a cohort of 44 men studied by Infinium HM450k methylation Beadchip (Table 11); (B) cohort of 125 men studied by quantitative PCR (Table 12); and (C) cohort of 178 men extracted from The Cancer Genome Atlas, for whom Infinium HM450k methylation Beadchip are publically available (Table 13). Panel (D) shows the methylation values detected in the urine samples from men undergoing trus-biopsy (n=283). In all cohorts, significantly higher levels of methylation are detected in the high-risk and high grade disease.
[0089] FIG. 11 are graphs illustrating SFRP2 methylation as detected in A) prostate tissues and B) urine samples from men undergoing TRUS-biopsy. In both cohorts, significantly higher levels of methylation are detected in the high-risk and high grade disease.
[0090] FIG. 12 are graphs illustrating IGFBP3 methylation as detected in (A) prostate tissues from men undergoing radical prostatectomy (Perry et al, British Journal of Cancer, 2007). Abbreviations: HGPIN: high grade prostatic intraepithelial neoplasia, HB: histologically benign and BPH: benign prostatic hyperplasia. (B) urine samples from men undergoing trus-biopsy, n=283. In both prostate tissue and urine, significantly higher levels of methylation are detected in the high-risk and high grade disease patients.
[0091] FIG. 13 are graphs illustrating IGFBP7 methylation as detected in (A) prostate tissues from men undergoing radical prostatectomy (Sullivan et al, Journal of Urology, 2012). Abbreviations: HGPIN: high grade prostatic intraepithelial neoplasia, HB: histologically benign and BPH: benign prostatic hyperplasia. (B) urine samples from men undergoing trus-biopsy, n=283. In both prostate tissue and urine, significantly higher levels of methylation are detected in the high-risk and high grade disease patients.
[0092] FIG. 14 are graphs illustrating APC methylation as detected in (A) prostate tissues from men undergoing radical prostatectomy (Murphy et al, Epigenetic Diagnosis and Therapy, 2015). Abbreviations: HGPIN: high grade prostatic intraepithelial neoplasia, TA: tumour associated benign. (B) urine samples from men undergoing trus-biopsy, n=283. In both prostate tissue and urine, significantly higher levels of methylation are detected in the high-risk and high grade disease patients.
[0093] FIG. 15 are graphs illustrating supporting data for LXN. DNA methylation was measured in three independent cohorts of radical prostatectomy samples (Tables 11 to 13), and in each case is significantly higher in high-risk/aggressive prostate cancer compared benign prostate tissue and/or low-risk or indolent prostate cancer. Two methodologies were used to quantitatively measure DNA methylation: Infinium HM450K BeadChip (A and C) and quantitative PCR (B). For simplicity, significance values are only shown for comparisons with aggressive prostate cancer.
[0094] FIG. 16 are graphs illustrating supporting data for MAGPIE-1B. DNA methylation was measured in three independent cohorts of radical prostatectomy samples (Tables 11 to 13), and in each case is significantly higher in high-risk/aggressive prostate cancer compared benign prostate tissue and/or low-risk or indolent prostate cancer. Two methodologies were used to quantitatively measure DNA methylation: Infinium HM450K BeadChip (A and C) and quantitative PCR (B). For simplicity, significance values are only shown for comparisons with aggressive prostate cancer.
[0095] FIG. 17 are graphs illustrating supporting data for DNAH10. DNA methylation was measured in three independent cohorts of radical prostatectomy samples (Tables 11 to 13), and in each case is significantly higher in high-risk/aggressive prostate cancer compared benign prostate tissue and/or low-risk or indolent prostate cancer. Two methodologies were used to quantitatively measure DNA methylation: Infinium HM450K BeadChip (A and C) and quantitative PCR (B). For simplicity, significance values are only shown for comparisons with aggressive prostate cancer.
[0096] FIG. 18 are graphs illustrating supporting data for ZMIZ1. DNA methylation was measured in three independent cohorts of radical prostatectomy samples, and in each case is significantly higher in high-risk/aggressive prostate cancer compared benign prostate tissue and/or low-risk or indolent prostate cancer. Two methodologies were used to quantitatively measure DNA methylation: Infinium HM450K BeadChip (A and C) and quantitative PCR (B). For simplicity, significance values are only shown for comparisons with aggressive prostate cancer.
[0097] FIG. 19 are graphs illustrating supporting data for CENPV. DNA methylation was measured in three independent cohorts of radical prostatectomy samples, and in each case is significantly higher in high-risk/aggressive prostate cancer compared benign prostate tissue and/or low-risk or indolent prostate cancer. Two methodologies were used to quantitatively measure DNA methylation: Infinium HM450K BeadChip (A and C) and quantitative PCR (B). For simplicity, significance values are only shown for comparisons with aggressive prostate cancer.
[0098] FIG. 20 are graphs illustrating supporting data for OR2L13. DNA methylation was measured in three independent cohorts of radical prostatectomy samples, and in each case is significantly higher in high-risk/aggressive prostate cancer compared benign prostate tissue and/or low-risk or indolent prostate cancer. Two methodologies were used to quantitatively measure DNA methylation: Infinium HM450K BeadChip (A and C) and quantitative PCR (B). For simplicity, significance values are only shown for comparisons with aggressive prostate cancer.
[0099] FIG. 21 are graphs illustrating supporting data for (A-C) F3. DNA methylation was measured in three independent cohorts of radical prostatectomy samples, and in each case is significantly higher in high-risk/aggressive prostate cancer compared benign prostate tissue and/or low-risk or indolent prostate cancer. Two methodologies were used to quantitatively measure DNA methylation: Infinium HM450K BeadChip (A, and C) and quantitative PCR (B). For simplicity, significance values are only shown for comparisons with aggressive (high-risk) prostate cancer
DETAILED DESCRIPTION
Materials and Methods
Statistical Methods:
[0100] Logistic regression is a standard method for modelling the relationship between a binary variable, in this case high-risk versus low-risk prostate cancer, and a set of continuous or categorical variables. For this analysis, the variables used for prediction consist of gene methylation values, as well as patient variables age and PSA. Mathematically this relationship is expressed as
[0000]
log
(
p
i
1
-
p
i
)
=
β
1
X
1
i
+
β
2
X
2
,
i
+
…
+
β
m
X
m
i
(
1
)
[0101] where p i is the probability that the nth patient is high-risk based on their methylation profile and clinical characteristics, which are represented by the X mi 's. The β m coefficients give the effect that each incremental change in methylation, age or PSA has on the log-odds of the patient being high risk of prostate metastasis.
[0102] Due to the cost of collection of biomarkers, and the general principle that simpler models lead to more robust predictions, one aim of the analysis is to choose the smallest number of predictor variables, the x m 's, which will yield the best performing prediction model.
[0103] A LASSO 1 logistic regression (discussed below), along with a standard logistic regression incorporating six genes were fit to the data. Logistic regression models for each of the separate genes were also fitted for comparison. All models were trained using repeated 5-fold cross-validation with bootstrap resampling. The optimal cut-off value for prediction was then chosen using the entire data set.
[0104] A common problem with building a prediction model on the entire dataset is that the model will tend to over fit the current data set and will then underperform when new data is predicted from the model. In general, more complex models will tend to adapt to the training data and will not generalise as well to new data. Therefore sparser models are preferred.
[0105] In an ideal case a model is fitted to some training data and then its performance is estimated on an independent test set. A model can be selected by choosing the model that performs best on the test dataset which consists of new unseen observations. For small datasets, a single split of the data into testing and training sets is often not possible.
[0106] Cross-validation is a method for performing multiple random training-test splits of a dataset. The process is as follows:
[0107] 1. Split the data into K equally sized portions (K is usually chosen to be between 5 and 10);
[0108] 2. Leave aside one of the K portions and train the model(s) on the all of the remaining K-1 portions together;
[0109] 3. Test the performance of the model(s) on the portion of the data that was set aside in step 2; and
[0110] 4. Repeat iteratively leaving out each of the K portions in succession.
[0111] This method gives a more accurate assessment of the out-of-sample prediction performance of the models than simply fitting the model to the entire dataset. To further account for uncertainty in the cross-validation process, the dataset is bootstrapped, i.e. resample the entire dataset with replacement, and perform cross-validation on each bootstrap iteration. For the analysis here, K=5 and 2000 bootstrap iterations were used.
[0112] All of the data is used in the model-building and assessment stages. The model building process used aims to mitigate against any optimistic bias. Due to the relatively small number of high-risk cases, splitting the data is not an efficient option. Ideally a test or hold-out set of data which were not used in the training step should be used on which to test performance. This should be done at a later stage using an independently collected test data set.
[0113] The LASSO is a penalised regression method for building prediction models which mitigates against over-fitting on a data set. The LASSO is a method for both model selection and estimation. In standard logistic regression, the model parameters are fitted using iterative maximum likelihood. This estimates the parameters which fit the data the best, and as such can over-fit to the training data. Penalised regression methods add a penalty term to the estimation equation which penalises large values of the coefficients. This is a form of shrinkage which can yield more robust results. In the case of LASSO, the penalty term shrinks some coefficients to zero, acting as a form of variable selection.
[0114] The strength of penalisation is determined by a parameter, λ. The optimal lambda value is found by running a further cross-validation iteration within each iteration of the outer cross-validation loop.
[0115] For the final assessment of the LASSO model, models chosen in the resampling and cross-validation iterations were searched and selected as the final model, the most frequently occurring model. The performance assessments and model parameters were then based on the iterations where this model occurred. Regression coefficients were then obtained by averaging over these iterations.
[0116] Samples
[0117] The epiCaPture test (method described herein) is performed on urine or urine cell-sediment. The urine cell-sediment is obtained by centrifugation (10,000×g for 10 minutes) of a first-void urine sample (up to 50 ml) following a digital rectal examination (DRE). The DRE consists of three strokes per lobe of the prostate gland. Enough pressure is applied to the prostate to depress the surface approximately 1 cm, from the base toe the apex and from the lateral to the median line for each lobe. Total nucleic acid is extracted from the cell sediment using a standard silica-membrane based extraction protocol (using a Qiagen total nucleic acid isolation kit, or similar commercially available product). Purified DNA (100 ng) is subject to bisulfite conversion (using a Qiagen epitect kit, or similar commercially available product).
[0118] Expression of the KLK3 gene is measured by qRT-PCR using a commercially available primer and probe assay (Assay ID Hs.PT.58.38546086 available from Integrated DNA Technologies). Positive expression of the KLK3 gene relative to a housekeeper gene (ACTB) indicates the presence of prostate cells in the urine sediment and validity of the urine sample for epiCaPture analysis.
[0119] A 648 bp synthetic gBlock® DNA sequence (IDT—SEQ ID NO: 19) was designed to contain the nucleotide sequences of bisulfite converted fully methylated internal control sequence (ACTB) and six DNA regulatory sequences (GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS2):
[0000]
AAAGGTGGAGGTAGTTAGGGTTTATTTGTATATTGATTTGAGATTAGTTG
AATAAAAGTGTATATTTTAAAAATGAGGTTAAGTGTGATTTTGTGGTGTG
GAAAGTTGCGCGGCGATTTCGGGGATTTTAGGGCGTTTTTTTGCGGTCGA
CGTTCGGGGTGTAGCGGTCGTCGGGGTTGGGGTCGGCGGGAGTTCGAAAA
GTTTTTCGGAGTTGCGCGCGGGTTTGTAGCGTTTCGTTCGCGTTGTTTTT
TCGGTGTTTCGTTTTTTCGCGTTTTAGTCGTCGGTTGTTAGTTTTTCGGG
GTTTCGAGTCGTATTTAGCGAAGAGAGCAAATTTTTTCGATATCGGTTCG
TCGTAGGGAGATTTTATTTCGAGAGCGGAAGGGGTAAGGGCGGCGGGGTT
AAGGAGATCAAAAAGCGGGCGTGAGATCGAGCGTTTATGGGTCGGTTACG
TCGGGTGTTCGTTTATTTTTCGACGTTAGTAGGAGCGCGAAATTATATGT
CGGTTACGTGCGTTTATATTTAGTTAATCGGCGGGTTTTCGACGGGAATG
GGGAGCGTTTTGGTTCAAACGGAAGCGTTCGGGTAAAGATTGCGAAGAAG
AAAAGATATTTGGCGGAAATTTGTGCGTTTGGGGCGGTGGAATTCAAA
[0120] An 885 bp synthetic gBlock® DNA sequence (IDT—SEQ ID NO: 20) was designed to contain the nucleotide sequences of bisulfite converted fully methylated internal control sequence (ACTB) and six DNA regulatory sequences (LXN, MAGPIE-1B, DNAH10, ZMIZL CENPV and OR2L13):
[0000]
AAAGGTGGAGGTAGTTAGGGTTTATTTGTATATTGATTTGAGATTAGTTG
AATAAAAGTGTATATTTTAAAAATGAGGTTAAGTGTGATTTTGTGGTGTG
GAAATGGGTTATTTTGGTTTAACGGGATTAGTAGTAGAGCGTCGTTCGTT
TTGTTTGTTGTTGGGTTCGGTTGTCGAGGCGGAAAAGTCGTAAGAAATTT
GTTTTTGGTTTTTGTAGGCGTTTGGGTTGTTTTATTTGAGAGTTGCGTAG
GGCGGTTTGGCGGTGGTTGTTGTTTATATAATTCGAAACGTCGAGGTGTT
GTGATTTTCGTTTCGTTAATTTTTTAGTTTTAGTTTTATTTGTAAGGTGG
GCGGGTTGTTTGTAAATCGGTCGGCGTGGGGTGGGGTCGTATTTTCGGTT
GTAGCGGTTAAAGGGTTTCGTCGTCGTTTTCGTTCGGAGGTTGGAGTGTT
GTTCGTCGGGTCGTGCGTTCGTTCGGTAGCGGCGTGTATTAGTATTATAA
ACGTTGGGACGTATTTGTTTGTTTAGTTTCGTAGGTAGAGGGGTTGCGTT
TGGGTTTACGTTCGCGATATTTAGAATTTATTCGTATTTGCGAAGGCGAA
AATACGTTTTTGTCGGTCGTTTAGTTTTTTGTAGGTGTAAGGGCGGATGT
TTTAGCGATTACGGGAGTCGGGTTGGGGAGGTTGGTGGGGGGCGGGGGGA
GTTTTAAATTTAGGTTCGTTTAGTTATAGGCGTTTAGGTTTAGTCGGAAA
TTGTCGGAGGACGCGTTGTTGCGAGATTAGTCGCGGCGTTTTTGGTAGTA
GTGGGCGTGTTTGCGGGTTTAGGAGGGTTTTTTTTTCGCGATCGTCGATT
ACGATGAGAGCGTGAAGATTTTTTCGAAAGGAAAA
[0121] A 643 bp synthetic gBlock® DNA sequence (IDT—SEQ ID NO: 21) was designed to contain the nucleotide sequences of bisulfite converted fully methylated internal control sequence (ACTB) and four DNA regulatory sequences (MTMR8, F3, CDH8 and GALNTL6):
[0000]
AAAGGGCGGTTTTGGTTTAAATTTTCGTTATTTGATTTTCGGCGAAAGTT
TTTATCGCGATATTTTGATCGTAGTCGTTTTCGTTAAAAAAGGTGGAGGT
AGTTAGGGTTTATTTGTATATTGATTTGAGATTAGTTGAATAAAAGTGTA
TATTTTAAAAATGAGGTTAAGTGTGATTTTGTGGTGTGGAAATTCGGTTT
ATTACGGCGGTTATTTTTCGGGTAGTGACGACGATCGAGACGGTGAGGGC
GGTTATCGTTGGGGAGGGAGGTTCGGGTTTAGGTTTGGAAGTAAAACGTG
TGGTTTGTTATATCGTCGGTTGTATTGGATTAGGATTATTTTTTATGAAG
GTTTGTTTTGTTAGTACGTAGTAGGTTTTAGTTTTTACGTCGTTTCGAAT
ATTTCGTAGAAATACGGGGTATGTATAACGAAACGGATTTCGTTTATGTT
TTTCGGAGTTATAGGGTTTGGTGCGGAGACGTAGGGCGGGCGCGTTGGGT
TTTGGGTGTTCGTAATTTAAAGTGTAGTTGGTGTAAACGGGTCGTTTTTA
TTTTTCGTAGTCGTCGCGTTTCGGTTCGTCGCGTTTTCGTCGGTATTATG
GAGGAATTTTTGGGATAATCGTTTGTAGTCGGCGATTGGGAAA
[0000]
TABLE 1
The gBlock ® (SEQ ID NO. 19) was used to construct to-fold
serial dilutions over a 6-log template concentration range to determine
the dynamic range and PCR efficiency of each epiCaPture assay:
Copy
Vol. of
Vol. of molecular
DNA conc.
Standard
number
gBlock (μl)
grade H 2 O (μl)
(pg/μl)
1
1,000,000
10 (WS)
173.8
0.544
2
100,000
10 (1)
90
0.0544
3
10,000
10 (2)
90
0.00544
4
1,000
10 (3)
90
0.000544
5
100
10 (4)
90
0.0000544
6
10
10 (5)
90
0.00000544
[0122] Quantitative methylation specific PCR (qMSP) is performed, as previously described 3-5 . The PCR efficiency of each of the assays (internal control and 6 targets) was rigorously evaluated by performing 5 independent replicates (each with 3 technical replicates) over a 6-log template concentration range ( FIG. 5 ). Bisulfite treated DNA is amplified in parallel TaqMan® PCR reactions performed with oligonucleotides specific for each of the target methylated DNA regulatory sequences (SEQ ID NOs 1 to 6) and the endogenous control gene ACTB (SEQ ID NO: 17). Samples are considered positively amplified when a comparative threshold cycle (C T ) of <50 was detected in at least two out of three replicates. A normalized index of methylation (NIM) was calculated, as previously described 6 , to determine the ratio of the normalized amount of methylated target to the normalized amount of ACTB in any given sample, by applying the formula:
[0000] NIM=[( TARGETsample /TARGET MC )/( ACTB sample /ACTB MC )]×1000 (2)
[0123] Where TARGET sample is the quantity of fully methylated copies of each of the sequences being sampled in any individual sample, TARGET MC is the quantity of fully methylated copies of each of the sequences being sampled in a commercially available fully methylated bisulfite converted human DNA sample (Qiagen product number 59655), ACTB sample is the quantity of bisulfite modified templates in any individual sample and ACTB MC is the quantity of bisulfite modified templates in the universally methylated control DNA.
[0124] All genomic sequences for GSTP1, SFRP2, IGFBP3, IGFBP7, APC, PTGS-2, LXN, MAGPIE-1B, DNAH10, ZMIZL CENPV, OR2L13, and F3 were obtained from the UCSC Human Genome Browser (http://genome-euro.ucsc.edu).
[0125] Results
[0126] Results from the study on 156 men ( FIGS. 3(A) to 3(D) ) demonstrate that the invention can non-invasively discriminate high-risk (metastatic) PCa from low-risk (less chance of metastasis) disease and benign enlargement of the prostate (AUC=0.86). In this cohort, a high score (NIM>1) had 100% specificity for PCa, and greatly outperformed PSA, which yielded a PCa-specificity of only 11.63%.
[0127] Table 2 is data relating to the cohort of 156 TRUS-biopsy patients. The exclusion criteria for the cohort were (1) metastases on an MRI and/or a bone scan and (2) not post-DRE.
[0000]
Biopsy positive
Biopsy negative
P value
N
108
48
Age (years)
Mean
69.95
64.85
0.008
Median
69.50
66
Range
53-85
42-82
PSA (ng/ml)
Mean
16.53
7.06
<0.0001
Median
10
6.10
Range
4.1-95.9
0.2-30.30
Risk group
LR
14
IR
58
HR
36
[0128] Urinary Detection of Prostate Cancer
[0129] For non-invasively distinguishing men who have prostate cancer form those who do not (or more strictly speaking, men with a positive biopsy from men with a negative biopsy), the best combination of biomarkers is GSTP1 used in conjunction with PSA. This is calculated using a LASSO model (Table 3, FIG. 3A ). This achieved a positive predictive value (PPV) of 92%, with a negative predictive value (NPV) of 52%, with a sensitivity and specificity for prostate cancer of 81% and 77%, respectively. The combination of six methylated DNA regulatory sequences (as defined by SEQ ID NOs 1 to 6) in the method described herein also performs well at non-invasive detecting prostate cancer: PPV=92%, NPV=51%, sensitivity=60% and specificity=89%.
[0000]
TABLE 3
Biopsy positive versus biopsy negative
Sensi-
Speci-
SEQ (Gene)
AUC
tivity
ficity
PPV
NPV
1 (GSTP1)
0.72 (0.66-0.77)
0.44
0.98
0.98
0.45
2 (SFRP2)
0.66 (0.60-0.72)
0.37
0.94
0.93
0.41
3 (IGFBP3)
0.65 (0.58-0.73)
0.41
0.89
0.89
0.41
4 (IGFBP7)
0.64 (0.58-0.70)
0.29
1
1
0.40
5 (APC)
0.68 (0.60-0.75)
0.49
0.87
0.89
0.44
6 (PTGS2)
0.63 (0.55-0.72)
0.34
0.98
0.97
0.41
PSA
0.76 (0.67-0.84)
0.88
0.51
0.80
0.67
All
0.75 (0.68-0.81)
0.60
0.89
0.92
0.51
LASSO (1
0.83 (0.74-0.89)
0.81
0.77
0.92
0.50
(GSTP1) +
PSA)
[0130] Urinary Detection of High-Risk Prostate Cancer
[0131] However, as stated already, the dilemma for prostate cancer detection is not in the ability to detect the entire spectrum of disease, for which PSA is already adequately doing, but to specifically detect high-risk disease with high likelihood to metastasise. For predicting high-risk prostate cancer according to D'Amico criteria 2 , the LASSO, which is the selection method used here, determines that GSTP1 and IGFBP3 are the best fit (Table 4, FIG. 3B ). This combination delivers a PPV 56% of and NPV of 94% for high-risk disease, with a sensitivity and specificity both at 82%. The combination of all 6 genes, performs slightly less well, delivering a sensitivity of 52% and a specificity of 92%, for high risk disease. The method described herein (and derivations of it) outperforms current clinical practice (PSA), which in this cohort was found to have a sensitivity of 100% and specificity of only 21% (at the 4 ng/ml cut-off) for high-risk disease.
[0000]
TABLE 4
Detection of high-risk disease
Sensi-
Speci-
SEQ (Gene)
AUC
tivity
ficity
PPV
NPV
1 (GSTP1)
0.78 (0.68-0.87)
0.70
0.87
0.61
0.92
2 (SFRP2)
0.77 (0.68-0.86)
0.67
0.85
0.55
0.90
3 (IGFBP3)
0.76 (0.66-0.86)
0.61
0.82
0.49
0.88
4 (IGFBP7)
0.77 (0.67-0.86)
0.58
0.91
0.63
0.88
5 (APC)
0.76 (0.66-0.86)
0.67
0.84
0.54
0.90
6 (PTGS2)
0.71 (0.60-0.82)
0.52
0.92
0.63
0.87
All six
0.84 (0.75-0.93)
0.79
0.82
0.55
0.93
LASSO (1
0.83 (0.75-0.92)
0.82
0.82
0.56
0.94
(GSTP1) + 3
(IGFBP3))
[0132] Urinary Detection of High-Grade Prostate Cancer.
[0133] The Gleason grading system is the strongest prognostic indicator for prostate cancer. It is a histological grading system based on the glandular pattern of the tumour. A Gleason score is obtained by the addition of the primary and secondary grades. The presence of Gleason grade 4 or higher, or a Gleason score of 7 or higher predicts a poor prognosis.
[0134] For predicting tumours with a high Gleason score (>=8), the combination of all 6 biomarkers outlined above outperforms all biomarkers assessed individually (Table 5, FIG. 3C ), with a PPV of 48%, a NPV of 96% and a sensitivity and specificity of 76% and 87%, respectively. Combining all six markers with PSA gives some improvement again, with a sensitivity and specificity of 86% and 82%.
[0000]
TABLE 5
Detection of high-grade disease
Sensi-
Speci-
SEQ (Gene)
AUC
tivity
ficity
PPV
NPV
1 (GSTP1)
0.74 (0.63-0.86)
0.67
0.82
0.38
0.94
2 (SFRP2)
0.78 (0.67-0.89)
0.67
0.88
0.48
0.94
3 (IGFBP3)
0.78 (0.67-0.90)
0.67
0.82
0.38
0.94
4 (IGFBP7)
0.77 (0.66-0.89)
0.71
0.78
0.35
0.94
5 (APC)
0.75 (0.62-0.87)
0.71
0.80
0.38
0.94
6 (PTGS2)
0.68 (0.54-0.83)
0.57
0.89
0.46
0.93
PSA
0.79 (0.71-0.87)
0.95
0.63
0.29
0.99
All 6
0.83 (0.73-0.94)
0.76
0.87
0.48
0.96
All 6 + PSA
0.86 (0.76-0.96)
0.86
0.82
0.44
0.97
LASSO (3
0.78 (0.67-0.90)
0.67
0.82
0.38
0.94
(IGFBP3))
[0135] Supplementary Data
[0136] The cohort size was increased from 156 men to 283 men.
[0137] Table 6 is data relating to the cohort of 283 TRUS-biopsy patients. The exclusion criteria for the cohort were (1) metastases on an MR 1 and/or a bone scan and (2) not post-DRE.
[0000]
Biopsy negative
Biopsy positive
P value
n (283)
135
148
Age (years)
mean
64.43
68.44
<0.0001
median
65
68
<0.0001
range
42-83
47-85
PSA (ng/ml)
mean
6.59
11.78
<0.0001
median
6.05
8.90
<0.0001
range
0.2-63.80
0.6-144
D'Amico Risk
Group
LR
29
IR
73
HR
48
Gleason
Score
6
41
7
74
8
11
9
21
10
1
[0138] epiCaPture was performed on the cohort of 283 men, consisting of 135 biopsy-positive men and 148 biopsy-negative men. The age and PSA characteristics of the cohort are presented in Table 6. Although the biopsy-positive group were significantly older and had a significantly higher median PSA level (8.90 versus 6.05), there is considerable overlap in the range of ages and PSA levels for both groups ( FIGS. 7A and 7B ). Indeed, the mean and median PSA levels for the biopsy-negative group are above the 4 ng/ml threshold widely used for indicating need for prostate-biopsy. The biopsy-positive cohort were considered in terms of risk-group stratification (according to the D'Amico criteria), which encompasses tumour grade (Gleason score), PSA level and clinical stage) and tumour grade stratification (Table 6, FIGS. 7C and 7D ).
[0139] Each of the 6 gene panel was analysed individually in each patient, and a normalised index of methylation (NIM) score was generated for each gene ( FIG. 8 ). Different approaches were studied to determine the best performing method to (1) discriminate biopsy positive from biopsy negative and (2) selectively detect high-risk and high-grade disease. The performance of individual genes versus different combinations was studied using LASSO and tree mathematical models. In each instance, the performance of an NIM threshold (equations 3 to 5 below) produced the best performance indices (positive and negative predictive power) (Table 7-9). The NIM equation normalises for the amount if input bisulfite modified DNA present in the sample and calculates the proportion of the target sequence which is methylated relative to a 100% fully methylated DNA sequence.
[0000] NIM=[(TARGET sample /TARGET MC )/( ACTB sample /ACTB MC )]×1000 (3)
[0140] NIM threshold for discriminating biopsy positive from biopsy negative was determined as 0.73:
[0000] NIM SUM (POSITIVE): (NIM Gene1 +NIM Gene2 ±NIM Gene3 ±NIM Gene4 ±NIM Gene 5 +NIM Gene6 )>0.73 (4)
[0141] Data from the 283 men show that for the 6 gene panel, the NIM threshold for detecting high-risk/high-grade disease was determined as 1.25 across the 6 gene panel.
[0000] NIM SUM (HIGH RISK): (NIM Gene1 +NIM Gene2 ±NIM Gene3 ±NIM Gene4 ±NIM Gene5 ±NIM Gene6 )>1.25 (5)
[0142] Detection of high-grade Prostate Cancer
[0143] By applying this model (NIM_SUM>1.25), epiCaPture has a comparable sensitivity for high-grade prostate cancer (>=Gleason score 8) compared with the predicate test, PSA (Table 9, FIG. 9 ). In this cohort of men, epiCaPture detected 84.85% of men with high-grade disease, as compared with 90.91% detected by PSA. The specificity and negative predictive value (Table 9, Table 10) of epiCaPture is far superior to PSA. Almost 98% of men with a negative biopsy tested negative for epiCaPture. Comparably, only 24.44% of the 135 men with a negative biopsy did not have an elevated PSA. This high false-positive rate (76%) of PSA is the reason why so many men undergo unnecessary biopsy.
[0000]
TABLE 7
epiCaPture performance characteristics:
biopsy positive versus biopsy negative
SEQ ID NO
Sensi-
Speci-
(Gene)
AUC
tivity
ficity
PPV
NPV
1 (GSTP1)
0.69
0.39
0.98
0.95
0.59
2 (SFRP2)
0.64
0.35
0.93
0.84
0.57
3 (IGFBP3)
0.65
0.35
0.93
0.84
0.57
4 (IGFBP7)
0.66
0.33
0.97
0.92
0.57
5 (APC)
0.69
0.43
0.93
0.86
0.60
6 (PTGS2)
0.66
0.40
0.93
0.87
0.59
Best 4 (1, 2,
0.75
0.45
1.00
1.00
0.63
3, 4)
Best 5 (1, 3,
0.76
0.49
0.99
0.97
0.64
4, 5, 6)
All 6
0.77
0.50
0.98
0.96
0.64
NIM Sum 4 (1, 3,
0.45
0.99
0.99
0.62
4, 5)
NIM Sum 5 (1, 2,
0.46
0.99
0.97
0.62
4, 5, 6)
NIM Sum >
0.55
0.93
0.9
0.65
0.73
Tree (G1 + G3)
0.76
0.9
0.5
0.97
LASSO (G1 +
0.76
0.56
0.9
0.86
0.65
G3 + G4 + G5)
[0144] Individual genes (targets) varied in their ability to discriminate presence of prostate cancer (biopsy-positive) from absence (biopsy-negative), ranging from a sensitivity of 33% (Gene 4) to 40% (Gene 6) (Table 7). Increasing the number of markers, for example, the best 4 or 5 or all 6, improved the sensitivity of urinary detection of prostate cancer to 45%, 49% and 50%, respectively.
[0145] However, summing the NIM across the gene panel and applying an NIM sum threshold of >0.73 improved the sensitivity to 55% of men with prostate cancer. The positive and negative predictive values for prostate cancer by applying an NIM sum threshold >0.73 are 90% and 65%, respectively.
[0000]
TABLE 8
epiCaPture performance characteristics:
detection of high risk disease
SEQ ID NO
Sensi-
Speci-
(Gene)
AUC
tivity
ficity
PPV
NPV
1 (GSTP1)
0.79
0.63
0.92
0.62
0.93
2 (SFRP2)
0.78
0.59
0.93
0.61
0.92
3 (IGFBP3)
0.78
0.46
0.97
0.78
0.90
4 (IGFBP7)
0.79
0.57
0.93
0.62
0.92
5 (APC)
0.78
0.61
0.92
0.60
0.92
6 (PTGS2)
0.74
0.48
0.95
0.63
0.90
Best 4 (2, 3,
0.81
0.87
0.63
0.31
0.96
5, 6)
Best 5 (1, 2,
0.80
0.87
0.52
0.26
0.95
3, 4, 6)
All 6
0.78
0.89
0.13
0.17
0.86
NIM Sum 4 (1,
0.80
0.88
0.56
0.96
3, 5, 6)
NIM Sum 5 (1,
0.83
0.85
0.52
0.96
2, 3, 4, 5)
NIM Sum >
0.83
0.85
0.52
0.96
1.25
Tree (G3 + G5)
0.74
0.91
0.61
0.95
LASSO (G3 +
0.86
0.89
0.70
0.36
0.97
G4 + G5 + G6)
[0146] Individual genes (targets) varied in their ability to detect high-risk prostate cancers, ranging from a sensitivity of 46% (Gene 3) to 63% (Gene 1) (Table 8). Increasing the number of markers, for example, the best 4 or 5 or all 6, does not markedly improve the accuracy of detecting high-risk prostate cancer, over individual markers, which can be attributed to the molecular heterogeneity of prostate cancer.
[0147] However, summing the NIM across the panel of best 4 or best 5 or applying an NIM sum threshold of 1.25 improved the sensitivity to 80% and 83%, respectively. The positive and negative predictive value for high-risk prostate cancer by applying an NIM sum threshold >1.25 are 52% and 96%, respectively.
[0000]
TABLE 9
epiCaPture performance characteristics:
detection of high -grade disease
SEQ ID NO
Sensi-
Speci-
(Gene)
AUC
tivity
ficity
PPV
NPV
1 (GSTP1)
0.773091
0.606061
0.892
0.425532
0.944915
2 (SFRP2)
0.79297
0.636364
0.92
0.512195
0.950413
3 (IGFBP3)
0.790545
0.515152
0.968
0.68
0.937984
4 (IGFBP7)
0.803212
0.606061
0.912
0.47619
0.946058
5 (APC)
0.783212
0.636364
0.896
0.446809
0.949153
6 (PTGS2)
0.728424
0.515152
0.932
0.5
0.935743
Best 4 (3, 4,
0.82
0.88
0.62
0.24
0.98
5, 6)
Best 5 (2, 3,
0.82
0.88
0.51
0.19
0.97
4, 5, 6)
All 6
0.76
0.88
0.08
0.11
0.83
NIM Sum 4 (2,
0.82
0.87
0.45
0.97
3, 4, 5)
NIM Sum 5 (2,
0.82
0.85
0.42
0.97
3, 4, 5, 6)
NIM Sum >
0.85
0.82
0.38
0.98
1.25
Tree (G3 + G6)
0.73
0.92
0.55
0.96
LASSO (G3 +
0.83
0.78
0.82
0.36
0.97
G5 + G6)
[0148] Individual genes also varied in their ability to detect high-grade (Gleason score >=8) prostate cancers, ranging from a sensitivity of 52% (Gene 3 and 6) to 64% (Gene 2 and 5) (Table 9). Increasing the number of markers, for example, the best 4 or 5 or all 6, does not markedly improve the accuracy of detecting high-grade prostate cancer, over individual markers, which can be attributed to the molecular heterogeneity of prostate cancer.
[0149] However, summing the NIM across the panel of best 4 or best 5 or applying an NIM sum threshold of 1.25 improved the sensitivity to 82% and 85%, respectively. The positive and negative predictive values for high-grade prostate cancer by applying an NIM sum threshold >1.25 are 38% and 98%, respectively.
[0150] By applying this model (NIM_SUM>1.25), epiCaPture has a comparable sensitivity for high-grade prostate cancer (>=Gleason score 8) compared with the predicate test, PSA (Table 10, FIG. 9 ). In this cohort of men, epiCaPture detected 84.85% of men with high-grade disease, as compared with 90.91% detected by PSA. The specificity and negative predictive value (Table 8, Table 9) of epiCaPture is far superior to PSA. Almost 98% of men with a negative biopsy tested negative for epiCaPture. Comparably, only 24.44% of the 135 men with a negative biopsy did not have an elevated PSA. This high false-positive rate (76%) of PSA is the reason why so many men undergo unnecessary biopsy.
[0000]
TABLE 10
Relative Sensitivity & Specificity
SENSITIVITY
epiCaPture high
PSA >= 4 ng/ml
n
n (%)
n (%)
Biopsy positive
148
70 (47.30)
136 (91.89)
False-negative rate
0.53
0.08
Gleason >= 8
33
28 (84.85)
30 (90.91)
False-negative rate
0.15
0.09
SPECIFICITY
epiCaPture negative
PSA < 4 ng/ml
n
n (%)
n (%)
Biopsy negative
135
132 (97.78)
33 (24.44)
False-positive rate
0.02
0.76
[0151] Quantitative analysis of DNA methylation at six gene loci in prostate tissues and urine samples indicates that high levels of methylation detected in high-risk tumour tissues can be measured in urine as a surrogate. Examples of this are shown for five of the six gene panel, Target 1 (GSTP1; FIG. 10 ), Target 2 (SFRP2; FIG. 11 ), Target 3 (IGFBP3; FIG. 12 ), Target 4 (IGFBP7; FIG. 13 ) and Target 5 (APC; FIG. 14 ).
[0152] Quantitative analysis of DNA methylation at the seven of the remaining ten gene loci that were analysed in prostate tissues indicates that high levels of methylation detected in high-risk tumour tissues can be measured. The genes were analysed on 3 independent cohorts of prostate tissue samples and all show consistent patterns of significant methylation in high-risk/aggressive prostate cancer. Examples of this are shown for Target 7 (LXN; FIG. 15 ), Target 8 (MAGPIE-1B; FIG. 16 ), Target 9 (DNAH10; FIG. 17 ), Target 10 (ZMIZ1; FIG. 18 ), Target 11 (CENPV; FIG. 19 ), Target 12 (OR2L13; FIG. 20 ) and Target 13 (F3; FIG. 21 ). The details of the three different cohorts used for the study relating to those genes listed above are provided below.
[0153] Cohort A
[0154] Benign prostate tissue was obtained from radical cystoprostatectomy or trans-urethral resection of the prostate, from men with no clinical or histopathological evidence of prostate cancer. Precursor lesions proliferative inflammatory atrophy (PIA) and high grade prostatic intra-epithelial neoplasia (HGPIN), (HGPIN) and primary tumours (indolent (PCI) and aggressive (PCA)) were all obtained from radical prostatectomy specimens. PCI was defined as Gleason 6, pT2 disease, with a pre-operative PSA <10 ng/ml and no evidence of biochemical or clinical recurrence (5-year follow-up). PCA was defined as primary Gleason ≧4, pT3 disease, with evidence of biochemical or clinical recurrence. Metastatic lesions were obtained from visceral metastases (liver and or lymph node), obtained during rapid autopsy. All patient samples were obtained retrospectively with ethical approval granted by the associated institutions: benign (St. James's Hospital (SJH), Ireland; Adelaide and Meath Hospital incorporating the National Children's Hospital (AMNCH), Ireland); PIA (SJH); HGPIN (AMNCH); PCI (SJH; Mater Misericordiae (MM), Ireland; Beaumont Hospital (BH), Ireland); PCA (SJH; MM; BH); PCM (University of Washington, USA).
[0155] In each case, H&E slides were reviewed by a consultant pathologist, who identified and marked the relevant target areas. Six serial 8 μm sections were cut from the respective formalin fixed paraffin embedded (FFPE) blocks and mounted onto PEN membrane glass slides (Life Technologies) for laser capture microdissection (LCM). The sixth section was H&E stained and reviewed to ensure a consistent percentage of target cells. LCM was performed to enrich for target epithelia as previously described, using the Arcturus XT system (Life Technologies). DNA and total RNA were isolated from LCM caps (harboring microdissected tissue) in parallel, using the QlAamp DNA micro kit (Qiagen) and RecoverAll Total Nucleic Acids isolation kit (Ambion), respectively.
[0000]
TABLE 11
Clinicopathologic data for Cohort A
Benign*
PIA*
HGPIN*
PCI*
PCA*
PCM
Number of cases
10
7
6
7
8
6
Mean age (years)
66.10
61.30
61.50
57.50
58.75
72.83
median
64.50
62.00
62.00
58.00
59.50
74.00
range
48-79
49-68
56-66
50-66
46-69
60-81
Mean PSA (ng/ml)
NA
7.74
8.05
5.23
8.00
62.48
median
8.94
7.90
5.40
7.25
51.95
range
3.18-9.89
5-11.60
3.60-7.10
4.50-13.60
41-105
Gleason score (n)
6
—
0
4
7
0
0
7 (3 + 4)
—
4
0
0
0
0
7 (4 + 3)
—
3
1
0
5
0
8
—
0
0
0
3
2
9
—
0
1
0
0
3
10
—
0
0
0
0
1
TNM stage (n)
pT2a
—
1
0
0
0
0
pT2b
—
0
1
0
0
0
pT2c
—
5
4
7
0
0
pT3a
—
1
1
0
4
0
pT3b
—
0
0
0
4
0
pT3c
—
0
0
0
0
0
pT4
—
0
0
0
0
6
BCR (n)
—
NA
NA
0
8
6
Abbreviations: PIA: proliferative inflammatory atrophy, HGPIN: high-grade prostatic intraepithelial neoplasia, PCI: indolent prostate cancer, PCA: aggressive prostate cancer, PCM: metastatic prostate cancer, BCR: biochemical recurrence, NA = not available.
*cohorts are age-matched.
[0156] Cohort B
[0157] A retrospective cohort of radical prostatectomy cases was used to validate potentially prognostic differentially methylated regions identified in cohort 1. All patient samples were obtained retrospectively with ethical approval granted by the associated institutions: benign (SJH, AMNCH) and tumor (SJH, MM and BH). Tumor samples were assigned as low-risk (Gleason score 3+3, pT2; n=23); significant (Gleason score 7, pT2; n=42); or high-risk (Gleason score ≧4+3, pT3; n=39), based on histopathological review of radical prostatectomy specimens. For control purposes, histologically benign prostate tissues (n=21) were procured from radical prostatectomy or trans-urethral resection of the prostate. Tumor and benign foci were marked by a consultant histopathologist (SPF, BL) and targeted macro-dissection with a scalpel was carried out on four serial 5 μm sections. DNA and total RNA were isolated using the RecoverAll Total Nucleic Acids Isolation kit (Ambion).
[0000]
TABLE 12
Clinicopathologic data for Cohort B
Tumor
Benign*
low-risk
significant
high-risk
Number of cases
21
23
42
39
Mean age (years)
65.9
59.7
60
62
range
44-87
49-70
48-73
49-74
Mean PSA (ng/ml)
5.5
6.6
6.8
8.2
range
0.42-10.4
1.2-12.3
2.4-14.7
3.1-18.7
Gleason score (n)
≦6
—
23
1
0
7 (3 + 4)
—
0
37
17
7 (4 + 3)
—
0
4
14
≧8
—
0
0
8
TNM stage (n)
pT2
—
23
42
0
pT3
—
0
0
39
pT4
—
0
0
0
[0158] Cohort C
[0159] In June 2014, The Cancer Genome Atlas (TCGA) database was mined for HM450k data for patient specimens corresponding to low-risk (n=9), significant (n=68) and high-risk (n=67) PCa as defined already for cohort 2. Histologically benign HM450k data were also retrieved (n=29). For each sample, raw *.IDAT files were extracted and processed through an abridged run of RnBeads (including pre-filtering, BMIQ normalization and post-filtering). β-values for probes contained within the 13 potentially prognostic DMRs were extracted and a mean DMR β-value was calculated for each sample. Methylation differences between cohorts were assessed using an unpaired T test with Welch's correction. Significance was ascribed as P<0.05.
[0000]
TABLE 13
Clinicopathologic data for Cohort C
Tumor
Benign*
low-risk
significant
high-risk
Number of cases
34
9
68
67
Mean age (years)
60.8
58
60.1
61.4
range
44-71
47-72
44-73
44-77
Mean PSA (ng/ml)
12.7
6.8
7.1
13.6
range
1.8-87
3.6-10
0.7-26.6
1.6-87
Gleason score (n)
≦6
—
9
0
0
7 (3 + 4)
—
0
56
0
7 (4 + 3)
—
0
12
35
≧8
—
0
0
32
TNM stage (n)
pT2
—
9
68
0
pT3
—
0
0
63
pT4
—
0
0
4
[0160] In the specification the terms “comprise, comprises, comprised and comprising” or any variation thereof and the terms “include, includes, included and including” or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa.
[0161] The invention is not limited to the embodiments hereinbefore described but may be varied in both construction and detail.
REFERENCES
[0000]
1. Tibshirani R. Regression shrinkage and selection via the LASSO. J. Royal. Statist. Soc B., 1996 vol. 58(1): 267-288.
2. Bastian P J, Boorjian S A, Bossi A, et al. High-risk prostate cancer: from definition to contemporary management. European urology 2012; 61(6): 1096-106.
3. Eads C A D K, Kawakami K, Saltz L B, Blake C, Shibata D, Danenberg P V, Laird P W. MethyLight: a high-throughput assay to measure DNA methylation. Nucleic Acids Research 2000; 28(8): E32.
4. Perry A S, Loftus B, Moroose R, et al. In silico mining identifies IGFBP3 as a novel target of methylation in prostate cancer. British journal of cancer 2007; 96(10): 1587-94.
5. Perry A S, O'Hurley G, Raheem O A, et al. Gene expression and epigenetic discovery screen reveal methylation of SFRP2 in prostate cancer. International journal of cancer Journal international du cancer 2013; 132(8): 1771-80.
6. Yegnasubramanian S, Kowalski J, Gonzalgo M L, et al. Hypermethylation of CpG islands in primary and metastatic human prostate cancer. Cancer Res 2004; 64(6): 1975-86.
7. Sullivan L, Murphy T M, Barrett C, Loftus B, Thornhill J, Hollywood D, Lynch T, Perry A S. IGFBP7 promoter methylation and gene expression analysis in prostate cancer. Journal of Urology (2012) 188(4) 1354-60. PMID: 22906661.
8. Murphy T M, Tuzova A V, O'Rourke C J, Greene C, Sullivan L, Thornhill J, Barrett C, Loftus B, Lynch T, Perry A S. Multigene Methylation Biomarker Analysis in Prostate Cancer. Epigenetic Diagnosis and Therapy, in press | A method of determining the risk of metastatic prostate cancer in an individual diagnosed with prostate cancer, the method comprising a step of assaying a biological sample obtained from the individual for the presence of at last one methylated regulatory DNA sequence selected from group comprising: SEQUENCE ID No's 1 to 16, or variants thereof, and correlating the presence or absence of the methylated regulatory DNA sequence with aggressive (metastatic) prostate cancer. | 2 |
BACKGROUND INFORMATION
1. Field of Invention
The present invention generally relates to wireless communication devices that are configured to provide for combined operation of a plurality of wireless protocols covering different parts of the frequency spectrum, and more particularly for transmitting LTE (long term evolution mode), CDMA (code division multiple access), UMTS (universal mobile telecommunications system), and GSM (global system for mobile communications) signals originated from different base stations BTS's (or transceivers) from a common antenna.
2. Description of Related Art
Continuing progress in wireless communications produces new and more sophisticated protocols that provide new services, which were not previously available. Implementation of these new technologies requires their collocation with the old base station technologies that are currently in use on the same site.
There are three commonly used methods for adding new services (e.g., LTE, UMTS, or WCDMA) to existing sites with existing BTS equipment (e.g. GSM or CDMA). The first method is to install additional antennas on the tower and run new feeder cables to connect to the new base station that is providing the new services (LTE, UMTS or WCDMA). This simple method results in additional tower loading that may require significant expense. In many cases, the incremental costs can be prohibitive or the addition of feeders and antenna's may be simply physically impossible. This is especially true at sites where several carriers are collocated.
The second method, which is widely used in the industry, utilizes multi-port hybrid combiners with operating bandwidths wide enough to accommodate the operation of the new services (LTE, UMTS or WCDMA channels) and existing services (GSM or CDMA channels). The drawback of this method is the significant insertion loss which is typically proportional to the number of channels connected to the corresponding ports of the combiner. These losses are caused by the non-coherent nature of the independent RF power sources (channels) connected to the hybrid combiner's input ports. As a result, most of the power is dissipated in the internal loads of the combiner which results in a significant loss of coverage at the site.
The third established method utilizes Multi-Channel Power Amplifier (MCPA) technology to combine multiple transmitters onto a common feeder line. The gain of this amplifier compensates for the losses of the hybrid combining which typically occurs ahead of the MCPA. However, in order to satisfy the linearity and power requirements of this type of operation, MCPA's must implement sophisticated linearization techniques including predistortion and/or feed-forward technologies, which make them complex and cost-prohibitive.
SUMMARY OF INVENTION
The present invention alleviates significant disadvantages of existing combining methods and provides for single antenna operation from multiple BTS's with different communication protocols co-located at the same site.
In exemplary embodiments, the present invention provides a system and a method for low loss and cost efficient combining of transmit and receive signals from multiple base stations, BTS's (or transceivers) with different protocols, operating at different frequency segments on the same antenna. For example, in accordance with one embodiment which is applicable for combining of two and more base stations on a single antenna, an arrangement is provided that uses a combination of a multi-branch reactive combiner, isolator, band-pass filters, and duplexers interconnected to form a multiplexer. This configuration utilizes the isolation properties of the multi-branch reactive combiner when presented with an impedance value close to a short or open circuit. In this case, the transformation properties of the combiner, which have a certain electrical length at each branch, create a very high impedance at the common junction for all other branches. This provides high isolation among each of the inputs to the junction.
In accordance with another embodiment, which is recommended for combining of small number of base stations (BTS's), an arrangement is provided, which uses a combination of circulators and band pass filters interconnected in a duplex or triplex configuration. This embodiment eliminates the use of multi-branch reactive combiner and reduces the number of band pass filters required. For example, for a two-BTS combiner, only one programmable band pass filter (BPF) is needed.
The employed multiplexer in accordance with various embodiments, can use identically tuned broad band duplexers, except that the common duplexer must be able to operate at the combined peak and average power of all the BTS's (or transceivers). The common Tx/Rx port of the first duplexer is externally connected to the antenna, the common Tx/Rx port of the second duplexer is externally connected to the first BTS, and the common Tx/Rx port of the third duplexer is externally connected to the second BTS, and the common Tx/Rx port of the N+1 duplexer is externally connected to the Nth BTS (or transceiver).
Furthermore, in accordance with various embodiments, the signals from the first BTS (or transceiver) enter the first input port of the module. The second duplexer separates the Tx and Rx signals, and the Tx signals pass through the first isolator oriented in forward direction, then to the band pass filter which is tuned to the Tx frequencies of the first BTS. The signals then pass to the first port of the reactive combiner (a first exemplary embodiment) or to the first port of circulator (a second exemplary embodiment) oriented for propagation in the forward direction and will propagate through the circuit with minimum insertion loss to the output ports of the reactive combiner or circulator connected to the Tx port of the output duplexer, and then to the common (antenna) port of the module.
In one embodiment, which utilizes a reactive combiner, the system has the first connecting branch of the combiner connected to the second port of the band pass filter (BPF). Each BPF has its' pass band tuned to the Tx frequency band of the specific BTS (or transceiver) to which it is connected. This filter rejects the Tx frequencies of all other BTS's, essentially presenting a short or open circuit impedance to these signals. The signals from a BTS connected to a specific branch will propagate through the junction port with very low insertion loss and, with properly selected electrical lengths of the branches, will see a very high impedance at other branches. Because of this very high impedance, each branch has very low power dissipation at its load from all other branches, thus providing high isolation between TX signals from the different BTS's. Isolators at each Tx port of the duplexers provide additional isolation between the sources. With proper filter tuning and the correct electrical length of combiner branches, all Tx signals are combined at the common port of the combiner with low loss and directed to the common antenna via the Tx port of the first duplexer.
In another embodiment the system employs three-port circulators instead of the reactive multi-branch combiner. This embodiment has the advantage of reducing the number of band pass filters required to N−1. However, it has diminishing returns as the number of Base Stations (or transceivers) increases. As N increases, there is a proportional increase in insertion loss as the Tx signals must pass through more circulators. Therefore the discussion below is limited for combining of two BTS's, which is the optimum number for this embodiment.
In this configuration, the first port of the circulator is connected to the first band pass filter, the second port of the circulator is connected to the output of the second isolator, which in turn is connected to Tx port of the third duplexer. The third port of said circulator is connected to the Tx port of the first duplexer and serves as a common port for the output for the transmit signals from both BTS's (or transceivers). The signal from the second collocated BTS (or transceiver) will be directed by the circulator to the Band Pass Filter via the first port of said circulator. Since the BPF will be tuned to the pass band frequency of the first BTS, the signal from the second BTS will be almost completely reflected by said filter and redirected to the third port of the circulator, thus realizing duplexing properties of the module.
In summary and in accordance with various embodiments of the invention all external interfaces are internally connected to certain ports of different components of the module, including broad band duplexers, broad band ferrite isolators, fixed frequency or programmable band pass filters, multi-port reactive combiner assembly, or 3-port circulators. Said components are arranged such that the output signals from O 1 to O n emitted from the common output port are related to corresponding input signals from I 1 to I n applied to individual input ports by the following matrix:
( O 1 O 2 ⋯ O n ) = ( I 1 I 2 ⋯ I n ) ( T 1 T 2 ⋯ T n ) ( 1 )
where T 1 . . . T n are transmission functions of the circuit for input signals I 1 , I 2 . . . . In and are close to unity for plurality of In.
In one exemplary embodiment the system utilizes reactive combiners, which require one band pass filter per combined transceiver. This method provides the lowest combing insertion loss. In another exemplary embodiment the system utilizes three-port circulators and requires N−1 band pass filters. This approach is ideal for combining a small number of base stations co-located on the site. For example if only two BTS's are to be combined, only one internal band pass filter is needed.
In accordance with various embodiments the system uses isolators connected to the Tx ports of duplexers as unilateral devices, which allows implementation of filters with lower rejection requirements to achieve required isolation between base stations or transceivers. Simplifying the rejection requirements lowers the number of resonators and coupling elements in the band pass filters. This is especially beneficial when tunable or programmable filters are utilized as the design is simplified, costs are reduced, and the lowest possible insertion loss is realized.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be best understood through the following description and accompanying drawings, wherein:
FIG. 1 illustrates a wireless communication system with N base stations (or transceivers) collocated on the same site, in accordance with one embodiment;
FIG. 2 shows internal connections between different components of multiplexer-combiner (LLC) module 100 in accordance with one embodiment;
FIG. 3 shows a more detailed diagram of the reactive combiner assembly 300 , in accordance with one embodiment.
FIGS. 4 a and 4 b are diagrams of the required impedance loading in the reactive combiner for two types of filters, in accordance with one embodiment;
FIGS. 5 a 5 b show the transmission coefficient for the reactive combiner as a function of the electrical length between the filters with short circuit ( FIG. 5 a ) and open circuit ( FIG. 5 b ) impedance at rejection frequency and common junction, in accordance with one embodiment;
FIG. 6 illustrates another embodiment which uses circulators instead of the reactive combiner, in accordance with one embodiment;
FIG. 7 shows an LLC configuration with circulator for the case N=2, in accordance with one embodiment;
FIG. 8 shows the block diagram of the path for the Tx signal from BTS 2 , in accordance with one embodiment; and
FIG. 9 shows charts for three levels of selectivity, where a(r 1 )=0.26 dB, a(r 2 )=0.56 dB, a(r 3 )=2.16 dB. a(r) denotes “selectivity” parameter or the sharpness of the rejection slope, in accordance with one embodiment.
DETAILED DESCRIPTION
FIG. 1 illustrates an exemplary embodiment of a wireless communication system with N base stations (or transceivers) collocated on the same site. The system includes a multiplexer-combiner (LLC) module 100 that allows operation of a number of base stations (transceivers) 120 on the same antenna 110 . In this configuration, the Tx/Rx ports of all tranceivers from BTS 1 to BTS(N) are connected to the same number of input ports 2 to N correspondingly of the (N+1)-port LLC 100 . The output port 1 of the LLC 100 is connected to a common antenna 110 and contains N Tx/Rx signals from all the combined base stations.
FIG. 2 shows internal connections between different components of multiplexer-combiner (LLC) module 100 . Multiplexer-combiner module 100 has a common port 1 , where all signals from the collocated base station transceivers are combined. Individual ports 2 to N are used to interface with the collocated base station transceivers. The Tx/Rx ports of each base station transceiver is connected to one of the individual input ports of multiplexer-combiner 2 to N, which direct the Tx/Rx signals to N identical broad band duplexers 180 for separate transmit and receive signal processing. The Tx signals are directed by the duplexers to the input ports of isolators 170 .
Isolators 170 , in accordance with both embodiments, are unilateral ferrite devices and serve the purpose of additional decoupling of the combined base station signals and minimizing the power leakage between the base stations. This is especially applicable in the event that the collocated BTS frequencies are closely spaced with narrow frequency margins between operating pass bands, which leads to limited rejection value produced by the filter and degradation of isolation properties of reactive combiner. For example, in accordance with one embodiment of the invention, the propagation coefficient is substantially limited to 0.95 minimum (leakage losses to 5% or 0.07 dB maximum) and the rejection requirement for the filter is specified to be 15 dB at 5% offset frequency from the corner of the pass band. Such a specification is achieved, for example, by using Chebyscheff filter with 1 dB ripple with five resonators. That means if BTS's with transmit power of 60 W are implemented in the collocated site, approximately 3 W×(N−1) of leakage power can reach the BTS connection port and produce undesirable intermodulation products. Using standard ferrite broad band isolators operating in the same frequency band as BTS's with isolation 20 dB, the leakage can be decreased to several hundred milliwats, which will not produce any noticeable nonlinear effect. Isolators 170 also serve the purpose of presenting constant impedance with good VSWR (Voltage Standing Wave Ratio) to the output of BTS, which is required for the normal operation of BTS output filter. Each isolator also protects the BTS from severe mismatched load in case of the reactive combiner malfunction. In accordance with other embodiments of the invention, a similar goal can be achieved by using BPF's with increased value of rejection parameters for out-of-band frequencies and elimination of the isolators. But that would lead to the increased number of resonators in the filters and added challenges in the design.
The Tx signals are then directed to band pass filters 160 that have a center frequency and pass band equal to the center frequency and bandwidth of the Tx signal of the corresponding base station transmitter. Band pass filters 160 also reject all frequencies located out of the pass band.
Each band pass filter 160 is connected to a reactive combiner 140 via a connecting transmission line 150 of a predetermined length. All of the transmission lines 150 join together and create a common combining port of combiner 140 . The combining port of the reactive combiner is connected to Tx port of the output duplexer 130 , which is designed for peak and average operating power equal to sum of the corresponding powers of the collocated BTS transceivers. Duplexers 130 and 180 can be broadband, covering the full Tx and Rx operating frequencies of the combined base stations. They must provide enough isolation between transmit and receive ports to avoid excessive desensitization of the receive port by the noise from BTS transmitter in Rx band, and from intermodulation effects caused by the leakage of the high power Tx signal into receive components chain.
FIG. 2 , shows distribution of the receive signal Rx coming from the duplexer 130 entering the input port of LNA 190 and then being split by the power divider 200 between Rx ports of the duplexers 180 .
FIG. 3 shows a more detailed diagram of the reactive combiner assembly 300 . It indicates the specific electrical length requirements of the connecting transmission lines. They can be an even or odd number of quarter wavelengths long depending on the type of the filter used in the assembly: even number of quarter wavelengths for filters presenting high impedance for signals out of the pass band, and odd number of quarter wavelengths for the filters presenting low impedance out of the pass band. This figure also details the interconnection of the components connected in series: isolator-filter-reactive combiner-output duplexer. Similar connections exist for each input Tx signal from each of the combined BTS transceivers.
FIGS. 4 a and 4 b are diagrams of the required impedance loading in the reactive combiner for two types of filters. FIG. 4 a demonstrates the impedances presented by neighboring filters to Filter 1 , which operates at frequencies that are out of pass band for all other filters. FIG. 2 shows the connections of the outputs of all filters at the common junction point. Therefore the signals from all BTS's propagate via transmission lines 150 and are present at ports 2 of each filter 160 as shown in FIG. 3 as well. With respect to FIG. 4 the following notation is used:
Z 1 , Z 2 , . . . Z n are impedances of each filter (from 1 to N) presented to the operating frequencies of all other filters connected in parallel at the junction point;
Z sh and Z op indicate open or short circuit impedance presented by each filter to the operating frequencies of all other filters; and
Z L is the impedance of the matched output load for the common port of reactive combiner;
I 1 , I 2 , . . . I n is the length of transmission lines between each filter and common junction.
In accordance with various embodiments of the invention, depending on the design of the filters used, each filter can present very high or open circuit impedance (for example, interdigital printed circuit type filters) or very low or short circuit impedance (for example, cavity type filters) at rejection frequencies. Cavity type filters with impedance close to short circuit have been used in this embodiment, but the selection of actual type of the filter depends on the specifics of the site with collocated BTS's and operating frequency band. The operation of various embodiments of the system does not depend on the type of the filter as long as the length of the connecting transmission lines is properly selected.
The value of the impedance of each filter at the pass-band frequencies of other filters has a significant effect on the operation of the reactive combiner. Typically the impedance never has an infinitely small or infinitely large value but usually has a complex nature with certain inductive (for the “short circuit” type) or capacitive (for the “open circuit” type) reactive component. This effect on the performance of the combiner can be easily compensated by adjusting the length of the connecting cables. Typically, for an inductive load, the length can be shortened slightly from the whole number of quarter wavelengths. For a capacitive load, it would be slightly lengthened. In practical applications these deviations are small.
If the frequency margin between operating bands is very small and part of the operating frequency of one or several BTS's falls in the pass band or close to 3 dB pass band of another filter, the filter does not present pure reactive load at the rejected frequency and the transmission line transformers will not realize high impedance at the junction for these frequencies. In this case a filter with steeper frequency rejection slopes must be selected to provide more than 15 dB rejection at undesirable frequencies.
To this end, the impedance at the junction point depends on the type of the termination and the electrical length of the transmission line connecting the filter The transmission line in accordance with various embodiments of the system, can use standard coaxial cables in case of connectorized interconnections, which is typical for coaxial cavity type filters. It also can be a part of printed circuit design if the filters use PC board technology. Actual selection of the type of the filter or transmission line does not affect the scope of this invention.
If the load (created by the other filters at the rejection frequency) is close to a short circuit, then the impedance presented by the parallel connection of N−1 filters to the signals at the pass band for each filter at the common junction is
Zin ′(1)=− j (1 /N− 1) Z 0 tg β1 =−j (1 /N− 1) Z 0 tg [(2π/λ)(2 n− 1)λ/4]; (2)
where Zin′ (1) is input impedance at the junction presented by any filter with a short circuit at the rejection frequency after transformation;
l is the electrical length from the junction to the filter, which presents short circuit termination;
β=2π/λ, propagation constant;
Z 0 is characteristic impedance of the transmission line
n≠0 is the number of quarter wavelength segments in electrical length
λ=(λ 1 +λ h )/2 is the wavelength at the center of the band covering Tx frequency of all BTS
In the above expressions λ 1 is the wavelength that corresponds to the lowest center frequency of the collocated BTS's; λ h is the wavelength that corresponds to the highest center frequency of the collocated BTS's.
Similarly, for the filters with open circuit impedance at rejection frequencies
Zin ″(1)= j (1 /N− 1) Z 0 cot β1= j (1 /N− 1) Z 0 tg [(2π/λ)2 nλ/ 4]; (3)
In this equation λ is the same as defined above.
where Zin″ (1) is the input impedance at the junction presented by any filter with an open circuit at the rejection frequency after transformation. When the 1 contains the correct number of λ/4, impedance at the junction presented by filters, which are “tuned out of band” for the operating frequency, becomes very high and there is almost no power leakage between the filters. This can be applied to any filter connected to the combiner, assuming that all filters are sufficiently narrow band and that each of them has high rejection for pass band frequencies of all other filters. In this case the combiner effectively has almost no losses caused by cross-coupling between the arms, which are transmission lines connecting filters to the common junction.
Considering that the propagation coefficient in equation (1) is equal
T=1−(Γ) 2 and β is a propagation constant, and considering (2), we can find T for short circuit terminations. In this expression Γ is reflection coefficient.
Equations (4) and (5) illustrate the transmission coefficients T 1 (I 1 ) for short and T 2 (I 2 ) open circuit terminations,
T 1 ( I 1 ) = 1 - ( - 1 1 + 2 * tan ( 2 π * I 1 ) ) ( 4 )
and from (3) for the open circuit terminations
T
2
(
I
2
)
=
1
-
(
1
1
+
2
*
tan
(
2
π
*
I
2
)
)
(
5
)
In these formulas I 1 and I 2 are equal L/λ, where L is the physical length of the transmission line.
Charts for propagation coefficient calculated using (4) and (5) are shown in FIG. 5 . FIG. 5 a and FIG. 5 b show the transmission coefficient for the reactive combiner as a function of the electrical length between the filters with short circuit ( FIG. 5 a ) and open circuit ( FIG. 5 b ) impedance at rejection frequency and common junction. The Horizontal axis in FIG. 5 a and FIG. 5 b show the electrical length normalized to the center frequency wavelength. The Vertical axis in FIG. 5 a shows the value of the transmission coefficient T 1 as a function of the length of transmission line I 1 from the short circuit termination to the common junction. The Vertical axis in FIG. 5 b shows the value of the transmission coefficient T 2 as a function of the length of transmission line l 2 from the open circuit termination to the common junction. As it can be expected, the optimal length for the short circuit terminated reactive combiner must be a multiple of λ/4 (quarter-wavelength) and for the open circuit termination it must be a multiple of (half-wavelength) λ/2. From that figure, the following table for the bandwidth limited to 10% losses (T>0.9) can be calculated
Length of
Frequency band
Termination
transmission line
width for 10% loss
Short Circuit
λ/4
76%
Short Circuit
¾ λ
25%
Open Circuit
λ/2
40%
Open Circuit
λ
19%
The above table demonstrates that the bandwidth of the reactive combiner is sufficient for wireless communication purposes where the frequency spectrum of the Tx transmissions does not exceed a few percentages from the carrier frequency. This embodiment requires one band pass filter per combined BTS and has the advantage of very low insertion loss, which is mostly determined by the filters frequency characteristics and frequency separation between the nearest combining transmitters. The advantage of this method is that there is no theoretical limit to the number of collocated BTS transceivers that can be combined. With a properly tuned system, all BTS transceivers will experience the same insertion loss with only a small degradation as the number of combining branches increases. The spectral efficiency which will be discussed later for various embodiments is determined by the sharpness of the slopes of the pass band filters.
FIG. 6 illustrates another embodiment which uses circulators instead of the reactive combiner. This arrangement needs N−1 number of band pass filters, where N is the number of combined BTS transceivers at the collocated site.
For the arrangement described in FIG. 6 , multiple BTS transceivers are shown to be combined using circulators as combining elements. In this embodiment, the Tx signal from N th BTS must propagate twice through (N−1) circulators, therefore the insertion loss of the selected type of circulators and the number of connected BTS transceivers plays a decisive role in embodiment type selection. In the configuration demonstrated in FIGS. 6 and 7 , the low loss combiner (LLC) 100 has multiple external ports from 1 to N shown in encircled numbers. External port 1 is common port, where all signals from collocated BTS are combined. Individual ports 2 to N used for interface with plurality of collocated BTS's.
The Tx/Rx ports of each BTS is connected to one of the individual input ports of LLC 100 from 2 to N, which direct the Tx/Rx signals to N−1 broad band identical duplexers 190 for separate transmit and receive signal processing. These duplexers can be of identical design, covering the full operating band for the collocated BTS's and must withstand the average and peak power of a single BTS.
The Tx signal(s) from the BTS appears on one of the two output ports of duplexers 190 directed to the input ports of isolators 160 . The Isolators provide additional protection to BTS from the leakage of the signals from other BTS's. They also serve the role of providing a constant impedance load for the BTS and provide protection from reflected signals in case of an antenna, malfunction.
The Tx signal(s) are directed to the Band Pass filters 170 , with the center frequency and pass band equal to the center frequency and bandwidth of the Tx signal(s) of the corresponding BTS. Filters 170 must have steep rejection characteristic for all frequencies located out of the pass band. They can be field tunable type or factory pre-tuned to fixed frequencies.
Port 2 of each filter 170 is connected to circulators 150 . Circulators are connected in series with each other with their number equal to N−1, where N is the number of BTS's. The low loss path orientation in the circulator is clock-wise with signals entering port 1 directed to port 2 , and signals entering port 3 directed to port 1 . The Tx signals from the Band Pass Filters enter port 3 of the circulators, which have a low loss path to port 1 . Then, the signal from i th BTS (i=2, . . . N) will enter (i−1) filter through the direct path between ports 1 and 3 of the circulator and will be reflected by the (i−1) filter, which is tuned to pass only (i−1) th BTS operating frequencies. This reflected signal reverses the direction of propagation and enters the (i−1) th , circulator from port 1 . There are (i) signals coming out from port 2 of the (i−1) th circulator. A similar process is repeated for all N transmit signals, thus realizing the multiplexing properties of the module. The combined power from all collocated BTS's comes out from the port 2 of the (N−1) th circulator and enters the Tx port of the high power duplexer 140 . This duplexer can also cover the same frequencies as duplexers 190 but must survive combined average and peak power from all BTS's. The combined signal will ultimately appear at the common port of the duplexer 190 and will be transmitted to the external antenna.
In this embodiment circulators play an important role and must posses good isolating properties no less than 20 dB, which limit combining losses to 1%. The operating power of the circulator is preferably equal to or more than the combined power of the BTSTx signals passing through the specific circulator. As it can be appreciated by those skilled in the art, the optimum insertion loss and lowest cost can be obtained when there are just two BTS transceivers (N=2).
FIG. 6 also shows the distribution of the receive signal entering from antenna into a common port of duplexer 190 and separated at the Rx port of this duplexer. The Rx port of duplexer 190 is connected to the input port of Low Noise Amplifier (LNA) 210 . After amplification with the gain no less than the order of power divider, which typically equals to the number of collocated BTS, signal is split between N outputs of power divider. Each output is connected to the Rx port of duplexers 190 , which direct them to the common ports of the duplexers and then to the corresponding BTS.
FIG. 7 shows an LLC configuration with circulator for the case N=2. It illustrates a wireless communication system with two BTS transceivers collocated on the same site. The system includes a multiplexer module LLC 100 that allows operation of BTS' and BTS 2 on the same antenna. In this configuration, the Tx/Rx port of BTS 1 and Tx/Rx port of BTS 2 are connected to two input ports 2 and 3 correspondingly of the 3-port LLC 100 . The output port 1 of the LLC 100 contains the two Tx and Rx signals from both BTS transceivers and is connected externally to a common antenna. As shown in FIG. 7 , the external interface 1 of the module 100 is internally connected to duplexer 140 and external interface 2 of the module 100 is connected internally to duplexer 190 , and external interface 3 of the module 100 is connected internally to duplexer 200 . FIG. 7 also shows the distribution of the receive signals Rx coming from the duplexer 140 . The receive signals enter the input port of LNA 210 , and are then split by the power divider 220 to the Rx port of duplexer 190 and the Rx port of duplexer 200 .
A typical duplexer separates two signals in the frequency domain present on one terminal into two outputs, one for each frequency band. This device allows independent processing of signals in each band. Duplexers are reciprocal devices and can be used to combine corresponding bands into one terminal. This invention deploys duplexers that cover standard frequency bands designated for receive and transmit in wireless systems using FDM (Frequency Division Multiplexing) method.
The Tx/Rx signals from BTS 1 enter the common port of duplexer 190 and come out on two different ports of the duplexer for separate processing. The Tx signal from the duplexer enters port 1 of the isolator 180 oriented for forward propagation. Exiting from port 2 of isolator 180 , the signals from BTS 1 enter port 1 of the Band Pass filter 170 , which is tuned to the center frequency of the Tx signal from BTS 1 and has a pass band limited to the bandwidth of the Tx signal from BTS 1 . Upon exiting from port 2 of the Band Pass filter 170 , the Tx signal enters port 1 of circulator 150 which is oriented for clock-wise propagation. Circulator 150 directs all signals coming to port 1 to port 2 and from port 3 to port 1 of the circulator. Port 2 of the circulator will direct the Tx signal from BTS 1 to the Tx port of Duplexer 140 , which n turn, directs the signal to the externally connected common antenna. The interconnections of the components as described above provides for low loss propagation of the signals from BTS 1 to the common antenna.
Tx signals entering the module from port 2 which is externally connected to BTS 2 enter the common port of duplexer 200 and come out at two different ports of the duplexer for separate processing. The Tx signals from duplexer 200 enters port 1 of isolator 160 oriented in the forward direction, providing low loss propagation of these signals to port 3 of the circulator 150 . Because of the clock-wise signal propagation of this circulator, all signals entering port 3 will be directed to port 1 of said circulator and will enter port 2 of the band pass filter 170 . Since the band pass filter is tuned to pass the Tx signals from BTS 1 and reject signals from BTS 2 , the BTS 2 transmit signal will be reflected from port 2 of the filter 170 , and will be directed back to port 1 of the circulator 150 where it will be directed to port 2 of said circulator because of its clock-wise propagation orientation. Similarly to the signals from BTS 1 , signals from BTS 2 will be directed to Tx port of duplexer 140 and subsequently emitted from the common antenna externally connected to port 1 . The antenna is typically a broad band device and provides low VSWR at all frequencies of operation for BTS 1 and BTS 2 .
The system described in this paragraph is an example of the application of LLC for small number of collocated BTS. For this case the second embodiment is recommended where the number of required filters is equal to N−1. For the two-BTS site shown in FIG. 7 , only one band pass filter is required. Uni-directional properties of circulator 150 do not allow any signals from port 1 of the circulator appear at port 3 (except in case of antenna malfunctioning), therefore there is no need for the filter in BTS 2 path.
The following section provides the theoretical analysis of the operation of a 3-port LLC.
The operation of the combiner for two Tx signals in matrix notation can be described as
( O 1 O 2 ) = ( I 1 I 2 ) ( T 1 T 2 ) ( 6 )
Where O 1 is the Tx output signal originated from BTS 1 ;
O 2 is the Tx output signal originated from BTS 2 ; I 1 is the Tx input signal from BTS 1 ; I 2 is the Tx input signal from BTS 2 ; T is the transmission function; From scattering matrix for S-parameters of the 3-port device the following matrix of algebraic representation follows
( b 1 b 2 b 3 ) = ( S 11 S 12 S 13 S 22 S 21 S 23 S 33 S 31 S 32 ) ( a 1 a 2 a 3 ) ( 7 )
Where b 1 , b 2 , and b 3 are voltage responses to incident voltages a 1 , a 2 , and a 3 at corresponding ports of the LLC.
Using the detailed drawings of the embodiment shown in FIG. 7 , in order to combine the two signals and eliminate coupling between ports 1 and 2 (provide maximum isolation between BTS 1 and BTS 2 ) and considering that there is no incoming Tx signal into port 3 , matrix ( 7 ) becomes
(
b
1
b
2
0
)
=
(
S
11
0
S
13
S
22
0
S
23
S
33
S
31
S
32
)
(
a
1
a
2
0
)
(
8
)
Assuming a perfectly matched network and infinite isolation provided by nonreciprocal devices with low loss direction oriented as indicated in FIG. 7 , combining the parameters of matrix systems (1) and (3) the following relationships can be obtained:
O 1 =b 1 2 , O 2 =b 2 2 ,
I 1 =a 1 2 , I 2 =a 2 2 , T 1 =S 31 2 , T 2 =R; (9)
where R is the power reflection coefficient of filter which serves as a band-pass filter for frequencies of operation of BTS 1 , and as a band-stop filter for frequencies of operation of BTS 2 .| As equation (9) shows, the transmission coefficient T is determined by the reflection coefficient R, which is actually the rejection value provided by the filter to undesirable frequency of BTS 2 . The higher the value of rejection provided by the filter, the lower the combining loss for BTS 2 .
FIG. 8 shows the block diagram of the path for the Tx signal from BTS 2 . Using the same notations as in previous diagrams, the signal from BTS 2 with power P 2 enters port 3 of circulator 150 and will be directed to port 1 of the circulator 150 connected to the band-pass filter 170 . In this case, the transmission coefficient of this transducer can be described by the equation:
T 2 =Γ| 1 2 |=( Z f2 −Z 0 )/( Z f2 +Z 0 ), (10)
where Z f2 is the complex impedance of the load presented by the filter 170 with pass band at f, at the terminals of the circulator 150 for the BTS 2 frequency f 2 . As one can see from equation (10), for an ideal system without losses, if Z f2 will differ significantly from Z o , then transmission coefficient will come close to T 2 =Γ| 1 2 |=1. Z f2 is the impedance presented by the first filter to the signal of BTS 2 operating at frequency f 2 . FIG. 8 shows that in order to have low combining loss (or high transmission coefficient) the reflection coefficient for f 2 must be as high as possible, which is controlled by the value of Z f2 . In this case P 2 *R≈P 2 because R≈1, where P 2 is the transmit power from BTS 2 and R is the reflection coefficient of the filter at frequency f 2 .
Typically, the available frequency spectrum is very limited and the need to locate two BTS operating bands as close as possible is highly desirable. In this case, the sharpness of the filter frequency characteristic is important. It determines the amount of reflection (and insertion loss) that the second BTS signals will experience. The highest rejection with a given number of resonators at a given frequency offset is provided by elliptical and/or Chebyshev filters, where there are nulls and polls at the rejection band. As an example of a possible implementation, the equation for the transmission coefficient of the LLC with a circulator using a Chebyshev second type band pass filter with six resonators is shown below
T 3 ( k ) := 10 log ⌈ 1 ⌈ 1 + 1 a ( r ) 2 ( Ucheb ( 6 , 1 k ) ) 2 ⌉ - 2 ⌉ ; ( 11 )
where a(r) is the selectivity parameter;
Ucheb is the Chebyshev polynomial function second type of the 6 th order; k=ω/ω 0 ; ω 0 =pass band corner frequency.
The charts in FIG. 9 are shown for three levels of selectivity, where a(r 1 )=0.26 dB, a(r 2 )=0.56 dB, a(r 3 )=2.16 dB. a(r) denotes “selectivity” parameter or the sharpness of the rejection slope.
With proper selection of the filter type and its parameters, the propagation coefficient can be made no less than T>0.9 for the second BTS operating at frequencies within a few percent from the BTS 1 pass band.
The terms Propagation Coefficient and Transmission Coefficient (T) are used interchangeably herein
Physical meaning behind this term can be expressed by:
T 1 =P 1 out /P 1 in and T 2 =P 2 out /P 2 in , where
P 1 out is the output power of the BTS 1 ;
P 1 in is the input power of the BTS 1 ;
P 2 out is the output power of the BTS 2 ;
P 2 in is the input power of the BTS 2 .
Thus, a dual band LTE and CDMA low loss combiner can be made in a very compact, efficient and cost effective manner. Since the systems and methods described herein are not limited to particular implementations or to any specific communication bands, it should be apparent that there can be many more embodiments and implementations within the scope of this invention. Accordingly, the invention is not restricted, except in light of claims and their equivalents.
While only certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes or equivalents will now occur to those skilled in the art. It is therefore, to be understood that this application is intended to cover all such modifications and changes that fall within the true spirit of the invention. | A system for combining a plurality of signals in a wireless communication device employs a plurality of base station duplexers each coupled to a corresponding base station from a plurality of collocated base stations, each base station capable of receiving and transmitting signals in accordance with a corresponding transmission protocol. Each duplexer includes a transmit and receive paths for allowing signals to be transmitted from the base station and further allowing signals to be received by the base station. Isolators are each coupled to a corresponding one of the transmit path of each of the duplexers. Bandpass filters are each coupled to an output port of a corresponding one of the isolator and a combiner receives signals provided by each one of the band pass filters. An antenna duplexer is coupled to an output port of the combiner via a transmit path, where the duplexer provides a combined signal of the collocated base stations to an antenna. The duplexer further includes a receive path for providing signals received by the antenna to a corresponding receive path of each of the base station duplexers. | 7 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to a through-wall flashing system for a building, and more specifically, to a through-wall metal flashing system that provides one or more thermal breaks between the exterior and interior conditions of a wall construction of the building.
BACKGROUND OF THE INVENTION
[0002] Through-wall flashing systems generally comprise a membrane used in a wall construction for the purpose of preventing the passage of water into a structure from a joint in the wall. Flashing devices can be used anywhere in a building where it is necessary to deflect water away from seams or joints or other areas where water runoff is concentrated. In the past, flashing devices have been comprised of sheet metal such as lead, aluminum, copper, galvanized steel, stainless steel and other architectural metals. These sheet metal components have been primarily used in flashing constructions due to their strength, workability and durability. However, these metal components, when used to connect exterior components of a building directly to interior frame, are at least partially exposed to external conditions and provide direct paths for thermal conductivity from the exterior of a building to an inside portion of a wall construction, or into the interior of the building itself. Such thermal conductivity is known as thermal bridging. Particularly, these metal substances provide negligible thermal resistance, such that hot and cold temperatures from the external environment are easily transferred through these metallic flashing devices. Thus, a need exists for a through-wall flashing system having flashing members with the structural rigidity of continuous metallic flashing members, while greatly reducing, if not eliminating, thermal bridging from exposed portions of the flashing members to internally disposed portions of the flashing members.
SUMMARY OF THE INVENTION
[0003] One aspect of the present invention includes a through-wall flashing system for use at an interface between a wall accessory and an exterior wall construction of a building. The flashing system includes at least one flashing strip having a polymeric core, wherein the polymeric core includes an interior flashing portion, an exterior flashing portion and a body portion extending therebetween. An exterior facing is operably coupled to and substantially surrounds the polymeric core, wherein the exterior facing is comprised of a plurality of adjacent surfaces. Thermal breaks are disposed between one or more of the adjacent surfaces of the exterior facing and are adapted to disrupt thermal communication along the exterior facing between the interior flashing portion and the exterior flashing portion of the flashing strip.
[0004] Another aspect of the present invention includes a through-wall flashing system for use in a wall construction. The flashing system includes a flashing member configured to be received within a cavity of the wall construction and includes an external flashing portion disposed along an exterior surface of the wall construction, an internal flashing portion disposed within the cavity of the wall construction, and a web portion extending between the internal and external flashing portions. The flashing member further includes a polymeric core having an upper surface and a lower surface with an exterior facing operably coupled to the upper and lower surfaces. A plurality of thermal breaks are disposed along the exterior facing, thereby separating or dividing the exterior facing into adjacent portions. The thermal breaks are adapted to thermally insulate adjacent portions of the exterior facing from one another, thereby reducing temperature transmission between flashing portions.
[0005] Yet another aspect of the present invention includes a through-wall flashing system for use in a wall construction. The flashing system includes a flashing strip having an interior flashing portion, an exterior flashing portion and a body portion extending between the interior flashing portion and the exterior flashing portion. The flashing strip further includes an exterior facing operably coupled to and substantially surrounding a polymeric core. Thermal breaks are disposed along a length of the exterior facing, and are adapted to disrupt thermal temperature transmission between interior and exterior surfaces of the wall construction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a flashing device according to one embodiment of the present invention;
[0007] FIG. 2 is a cross-sectional view of the flashing device of FIG. 1 taken at line II;
[0008] FIG. 3 is a fragmentary cross-sectional view of a flashing device according to another embodiment of the present invention shown in an environmental view in a wall construction; and
[0009] FIG. 3A is a fragmentary cross-sectional view of a flashing device according to another embodiment of the present invention shown in an environmental view in the wall construction of FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
[0011] Referring to FIG. 1 , the reference numeral 10 generally designates a flashing member or strip according to one embodiment of the present invention. The flashing member 10 is adapted for use in a flashing system. As shown in FIG. 1 , the flashing strip 10 includes a plurality of panel portions with a first panel 12 , a second panel 14 and a third panel 16 . The first and third panels 12 , 16 are generally vertical panels attached to one another by intermediate second panel 14 which, in this embodiment, is substantially horizontal. It is contemplated that in assembly the intermediate panel 14 may have a downward cant from the first panel 12 towards the third panel 16 , thereby providing a gravitational drain for any moisture that comes into contact with the flashings strip 10 . As shown in FIG. 1 , the flashing strip 10 has an overall stepped configuration, however, other configurations are contemplated for use with the present invention. The first panel 12 defines an interior or internal flashing portion and includes an inner surface 18 and an outer surface 20 . Panel 14 defines a web or body portion and includes an upper surface 22 and a lower surface 24 . The third panel 16 defines an exterior or external flashing portion and includes an inner surface 26 and outer surfaces 28 and 29 . In assembly, the exterior surfaces or skins 20 , 22 , 28 and 29 are potentially exposed to environmental conditions A on an exterior side 10 A of the flashing strip 10 . Interior surfaces or skins 18 , 24 , 26 are disposed on an interior side 10 B of the flashing strip 10 , and are generally adjacent to the building construction materials which are subject to interior conditions B. Together, the inner and outer surfaces 18 , 20 , 22 , 24 , 26 , 28 and 29 of the panels 12 , 14 and 16 define an exterior facing 32 for the flashing strip 10 which is an exterior shell having thermal breaks as further described below.
[0012] Collectively, the exterior surfaces or skins of the flashing strip 10 are generally comprised of sheet metal made from lead, aluminum, copper, galvanized steel, stainless steel, zinc alloy or lead coated copper. Other sheet metal substrates are also contemplated for use with the present invention. The metal surfaces provide the malleability, strength and durability necessary to prolong the life of the flashing strip 10 . However, in known flashing devices, a continuous or uninterrupted flashing made from a sheet metal material is known to cause thermal bridging from outside environmental conditions to the interior or wall construction of a building. To counter these thermal bridging effects, the flashing strip 10 of the present invention includes thermal breaks disposed on the panel portions 12 , 14 and 16 of the flashing strip 10 .
[0013] Referring now to FIGS. 1 and 2 , the flashing strip 10 is shown having a polymeric core 30 disposed within the exterior facing 32 defined by interior and exterior surfaces 18 , 20 , 22 , 24 , 26 , 28 and 29 of the panels 12 , 14 and 16 . In the embodiment shown in FIGS. 1 and 2 , interior panel portion 12 is a generally upright panel portion and includes interior metal surface 18 and exterior metal surface 20 having a polymeric core portion 30 A disposed there between. Similarly, generally horizontal or downwardly sloping web or body panel portion 14 includes a polymeric core portion 30 B disposed between interior metal surface 24 and exterior metal surface 22 . Finally, in the embodiment shown in FIGS. 1 and 2 , downwardly facing exterior panel portion 16 includes polymeric core portion 30 C disposed between interior metal surface 26 and exterior metal surface 28 . The polymeric core 30 is generally comprised of an anticorrosive polymeric material that exhibits high insulative qualities or rather, demonstrates high R-value properties such as an R-value in the range of about R.2 to about R8 per inch. Polymeric materials suitable for the polymeric core of the present invention include thermoplastics or thermoset resin materials including for example: acrylonitrile-butadiene-styrene (ABS) copolymers, vinylesters epoxies, phenolic resins, polyvinyl chlorides (PVC), polyesters, polyurethanes, polyphenylsufone resin, polyarylsulfones, polyphthalimide, polyamides, aliphatic polyketones, acrylics, polyxylenes, polypropylenes, polycarbonates, polyphthalamides, polystyrenes, polyphenylsulfones, polyethersulfones, polyfluorocarbons, bio-resins and blends thereof. Other such thermoplastics and thermoplastic resins suitable for the present invention are known in the art which demonstrate high R-values and are thereby heat resistant as well as anticorrosive. Thermoplastics of the present invention are also contemplated to incorporate a recyclable polymer or are made of a polymeric material which is partially comprised of a renewable resource such as vegetable oil or the like. Further, microspheres, such as polymeric or glass nanospheres, can be added to the makeup of the polymeric core 30 to provide further insulative properties and increased R-value expression. When necessary, the polymeric core 30 can also be reinforced or doped with a reinforcing fiber such as fiber glass, carbon fibers, cellulose fibers, aramid fibers, and other such reinforcing agent to provide added structural rigidity to the flashing strip 10 .
[0014] In assembly, the polymeric core 30 forms a thermal break between exterior metal surfaces or skins, such as surfaces 20 , 22 and 28 shown in FIGS. 1 and 2 , and interior metal surfaces or skins, such as surfaces 18 , 24 , and 26 shown in FIGS. 1 and 2 . Metal surfaces 18 , 24 , and 26 are commonly in thermal communication with building substrates or wall constructions in assembly, as these surfaces are often disposed directly adjacent to the building substrate in which they are used. In other known flashing systems, this contact between metal surfaces and building substrates creates a thermal path or thermal gradient of least resistance that allows heat (or cold) to enter or escape, thereby creating vulnerability in a wall construction for cold spots and moisture problems. In the present invention, the sandwiched position of the polymeric core 30 between interior and exterior metal surfaces ( 18 , 24 , 26 and 20 , 22 , 28 ) ensures that heat (or cold) is not transferred to the building substrate in an effort to control the temperature within a building structure. Thus, the polymeric core 30 reduces or altogether eliminates thermal conductivity from the exterior metal surfaces 20 , 22 and 28 to a building substrate in assembly.
[0015] The flashing strip 10 , as shown in FIGS. 1 and 2 , of the present invention also combats thermal bridging by incorporating thermal breaks in the exterior facing 32 of the flashing strip 10 . For example, in the embodiment shown in FIG. 2 , the flashing strip 10 includes exterior metal surface 20 which, in this embodiment, is an L-shaped surface having a generally upright portion 20 A and a generally planar portion 20 B. The portions 20 A and 20 B of metal surface 20 are operably coupled to an upper surface 30 D of the polymeric core 30 along core portions 30 A and 30 B respectively. The metal surfaces of the exterior facing 32 of the flashing strip 10 are generally affixed to the polymeric core at inner and outer core surfaces 30 A, 30 B by continuous bonding. Interior metal surface 18 is also an L-shaped metal surface which includes upright portion 18 A and horizontal portion 18 B which is operably coupled to inner surface 30 E of the polymeric core 30 . Exterior metal surface 22 is a generally planar metal surface that is operably coupled to the outer surface 30 D of the polymeric core 30 and is spaced apart from portion 20 B of exterior metal surface 20 by a gap or spacing 40 A, thereby defining a thermal break 40 A therebetween. Similarly, interior metal surface 24 is operably coupled to inner surface 30 E of the polymeric core 30 and is spaced apart from portion 18 B of interior metal surface 18 at a spacing or gap 40 B disposed on the underside 10 B of the flashing strip 10 . Thermal breaks 40 C and 40 D are also found on panel portion 14 on exterior and interior sides 10 A and 10 B of the flashing strip 10 as shown in FIG. 2 . Thermal break 40 C is disposed in a spacing between planar portion 28 B of metal surface 28 and metal surface 22 . In the embodiment shown in FIG. 2 , exterior metal surface 28 includes an upright portion 28 A and a planar portion 28 B, while interior metal surface 26 , disposed on an opposing side of polymeric core portion 30 C relative to exterior metal surface 28 , includes a generally upright portion 26 A and a generally planar portion 26 B. Thermal break 40 D is disposed in a spacing between planar portion 26 B and metal surface 24 . As further shown in FIG. 2 , a thermal break 40 E is defined in a spacing between upright portion 28 A of exterior metal surface 28 and metal surface 29 disposed on panel portion 16 of the flashing strip 10 .
[0016] Having thermal breaks 40 A- 40 E disposed along the interior surface 10 B and exterior surface 10 A of the flashing strip 10 provides for a break-up in thermal communication between surfaces in contact with a building substrate and interior environment B, and surfaces exposed to exterior environmental conditions A. Thus, the present invention provides a polymeric core 30 sandwiched between interior and exterior metal surfaces, and also provides thermal breaks 40 A- 40 F disposed laterally along the length of exterior facing to adequately reduce thermal communication or temperature transmission into and out of a building interior or a cavity within a wall construction. The thermal breaks 40 A- 40 E provide for a substantially non-continuous exterior facing 32 disposed about the majority of the polymeric core 30 , wherein the non-continuous exterior facing 32 is made up of the interior and exterior metal surfaces disposed on panel portions 12 , 14 and 16 . Having thermal breaks 40 A- 40 F, which run the entire length of the flashing strip 10 , ensures that thermal bridging does not occur between adjacent metal portions of the exterior facing 32 . Thus, thermal breaks 40 A- 40 F serve to isolate and thermally insulate adjacent portions of the exterior facing 32 from one another, thereby reducing temperature transmission between flashing portions 12 , 14 and 16 of the flashing strip 10 . It will also be understood that, preferably, the thermal breaks on opposing sides of the polymeric core are offset from each other, that is, the thermal break 40 A is offset from thermal break 40 B so that to provide enhanced rigidity to the flashing. As such, a portion of the metal surface opposes the thermal break 40 B on the other side of the polymeric core. The same is true of the remaining thermal breaks. Additionally, it is preferred that the thermal breaks are spaced apart from the corners or edges where the panel portions meet.
[0017] The configuration and dimensions of the panel portions 12 , 14 and 16 of flashing strip 10 can be determined by the architectural requirements of the flashing needs for a particular building substrate or wall construction. A typical thermal gap, such as thermal gaps 40 A- 40 E shown in FIGS. 1 and 2 , may comprise a substantially uniform channel along the length of the flashing strip, and, may be approximately 0.25 mm, but can also be adjusted for architectural specifications. In the embodiment shown in FIGS. 1 and 2 , it is contemplated that the polymeric core 30 may be dimensioned to have a thickness in a range of about 3 mm to 6 mm to adequately provide interruption of a thermal gradient. The flashing system of the present invention is a customizable flashing system, wherein a plurality of flashing strips or members, such as flashing strip 10 described above, are customized to surround or encase a wall accessory in a wall construction, such as a window, vent, chimney or other like structure. As used throughout this disclosure, panel portions, such as panel portions 12 , 14 and 16 described above, are flashing portions of a flashing member, wherein an exterior shell, such as exterior shell 32 , provides thermal breaks between the flashing portions. The thermal breaks are suitable to interrupt temperature transmission between adjacent flashing portions, thereby limiting unwanted temperature changes into and out of a building.
[0018] Referring now to FIG. 3 , a standard window sill detail is shown having a flashing strip 100 according to another embodiment of the present invention. The flashing strip 100 includes panel portions 112 , 114 and 116 which are similar in configuration to panel portions 12 , 14 and 16 as described above with reference to flashing strip 10 . The flashing strip 100 includes an upper or outer surface 100 A and a lower or inner surface 100 B. As shown in FIG. 3 , the flashing strip 100 is disposed between a curtain wall system 60 and a metal stud wall construction 70 . The curtain wall system 60 includes an outwardly facing exterior wall 62 and a bottom wall 64 . In assembly, the bottom wall 64 of the curtain wall system 60 is disposed adjacent the upper side 100 A of the flashing strip 100 . The metal stud wall construction 70 may be an insulated wall construction which includes a weather barrier or exterior sheeting layer 72 coupled thereto using fasteners 74 . The fasteners 74 are further used to couple a polymeric bracket system 76 to the metal stud wall construction 70 . An exterior cladding system includes composite panels 80 and 82 which are coupled to the polymeric bracket system 76 using brackets 81 and fasteners 84 . The wall construction 70 and curtain wall system 60 are representative of assemblies that could be used with the present invention, however, they are not meant to limit the scope of the invention and are exemplary only. As shown in FIG. 3 , the curtain wall system 60 , the flashing strip 100 , wall construction 70 and exterior cladding units 80 , 82 are all potentially exposed to an exterior environment A and an interior environment B along portions thereof.
[0019] The flashing unit 100 , as shown in FIG. 3 , includes a polymeric core 130 surrounded by an interrupted exterior facing 132 . The exterior facing 132 is contemplated to be comprised of a sheet metal material. The exterior facing 132 is considered interrupted, in that the exterior facing 132 includes a plurality of thermal breaks which are identified in FIG. 3 as thermal breaks 140 A- 140 F. Similar to the thermal breaks noted above, thermal breaks 140 A- 140 F are defined by spacings provided along the entirety of the exterior facing 132 of the flashing strip 100 , such that thermal communication between adjacent portions of the exterior facing 132 is interrupted and non-continuous.
[0020] Referring now to FIG. 3A , a flashing strip 200 having an upper or outer side 200 A in an inner or underside 200 B is shown disposed between curtain wall system 62 and wall construction 70 . The flashing strip 200 includes panel portions 212 , 214 and 216 , wherein web panel portion 214 has a downward cant as it extends from panel portion 212 to panel portion 216 . In this way, the flashing strip 200 is disposed between a lower surface 64 of the curtain wall system 60 and an upper wall 78 of the wall construction 70 . The downward cant of web panel portion 214 helps to gravitationally drain moisture from the wall system in assembly. As shown in FIG. 3A , interior panel portion 212 is disposed within a reglet 66 of the curtain wall system 60 , while exterior panel portion 216 is disposed adjacent to outer cladding unit 80 . The flashing strip 200 includes a substantially non-continuous exterior facing 232 which is generally comprised of a sheet metal material having thermal breaks 240 A- 240 G disposed therealong. Flashing strip 200 further includes a polymeric core 230 similar to cores 30 and 130 described above. The polymeric core 230 , along with the thermal breaks 240 A- 240 G disposed in the exterior facing 232 of the flashing strip 200 , helps to insulate the wall construction from environmental conditions disposed on side A of the wall construction that would otherwise thermally bridge to the interior side B, if the exterior facing 232 were in fact continuous and uninterrupted.
[0021] The flashing members used in the flashing system of the present invention have a universal attachment design for use with virtually any wall construction or stud wall. For instance, the flashing members of the present invention can be used with structures having concrete masonry units (CMU Walls), composite wall panels, brick walls on CMU or stud walls, terra cotta on stud walls, and on stud wall configurations alone. As noted above, heat travels in the path of least resistance such that heat can invade a wall system and affect an interior atmosphere through relatively finite pathways such as fasteners and the like that have metal to metal contact with exterior conditions. Similarly, exterior exposure to cold temperatures can allow for infusion of cold temperatures into a wall construction along highly thermally conductive components. Most applications of metal flashings retain at least some form of metal to metal contact through metal anchors, fasteners, or sill, transition, and window trim. Fasteners used to couple the flashing members of the present invention to a wall construction do not bridge the thermal breaks of the flashing members and therefore do not thermally bridge the exterior conditions A with the interior conditions B.
[0022] It is also to be understood that variations and modifications can be made on the aforementioned structures and methods without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise. | A through-wall flashing device includes a metal exterior surrounding a polymeric core, wherein the metal exterior is substantially non-continuous or otherwise interrupted by thermal breaks disposed about the metal exterior. In assembly, the thermal breaks help to reduce or all together eliminate thermal bridging from an exterior of a building construction to the interior of a building or building wall. The through-wall flashing device is adapted for use with a variety of wall constructions and is specifically configured to provide insulation and moisture sheeting properties around doors, windows and other architectural apertures which may be found in a wall construction. | 4 |
FIELD OF THE INVENTION
The present invention relates to a precombustion chamber with insulating means, i.e., to an arrangement for thermal insulation for enhancing the combustion efficiency by thermally insulating a cylinder head from a combustion gas in the precombustion chamber, particularly of the swirl (or turbulence) chamber type, of an internal combustion engine.
BACKGROUND
Although various attempts have been made to form a mouth piece of the precombustion chamber by ceramics mainly for enhancing of the combustion efficiency of diesel engines, thermal insulation only at the mouth piece is not sufficient from the view point of performance. Research has recently been done to form the chamber by ceramics for thermally insulating the same. If the thermal insulator of ceramics is in contact with a hollow space provided in the cylinder head, heat dissipation would be high, resulting in a low thermal insulation effect. Therefore it has been proposed that an air thermal insulation layer be provided around the outer periphery of a ceramic body to compensate for the low thermal insulation. (Refer to Japanese Utility Model Kokai Publication No. B59-21024 entitled "Precombustion chamber for internal combustion engine".)
SUMMARY OF THE DISCLOSURE
It is very difficult to maintain complete sealing against the combustion gas at high temperature and pressure. In the aforementioned JP Utility Model Kokai, the side of the cylinder constituting a fitting portion between the cylinder head and the ceramic body in which a combustion chamber is formed is sealed between the cylinder head and a cylinder block by means of a gasket. Therefore the ceramic body is partly supported by the gasket when the cylinder head is assembled to the cylinder block. This involves disadvantages in that the precombustion chamber is unstable due to the fact that it is tilted or raised if the fabrication precision of the ceramic body is not so high and/or if the gasket or seal means deforms.
It is therefore an object of the present invention to provide an arrangement for thermally insulating a precombustion chamber having an excellent combustion efficiency in which sealing properties and mechanical stability are improved.
In accordance with the present invention there is provided a precombustion chamber provided with an arrangement for thermally insulating a cylinder head of an internal combustion engine from a combustion gas in the precombustion chamber comprising:
(a) a hollow ceramic body which provides a precombustion chamber and is disposed within the hollow space for the precombustion chamber within the cylinder head;
(b) a hollow fitting member disposed surrounding the hollow ceramic body within the hollow space for mitigating and absorbing the stress produced between the cylinder head and the hollow ceramic body; and
(c) seal means for sealing a space between the hollow ceramic body and the fitting member to provide a closed space therebetween,
wherein said hollow fitting member is tightly secured to the hollow ceramic body through the seal means.
The arragement for thermally insulating a precombustion chamber of the present invention comprises the hollow ceramic body which is firmly fitted in the hollow space for the precombustion chamber by interposing between the hollow space and the hollow ceramic body a fitting member which mitigates and absorbs the stress produced between the cylinder head and hollow ceramic body, the fitting member being secured be interposing seal means between the hollow ceramic body and the fitting member. Thus the arrangement of the present invention can be fitted into the hollow space of the cylinder head by fitting techniques applicable to usual metal components, such as shrinkage fit, expansion fit, press-fit or the like. Therefore the present arrrangement provides a high reliability of sealing at both fittings between the hollow ceramic body and fitting member and between the fitting member and the cylinder head, and is mechanically stable with respect to the cylinder head.
For the same reason the precombustion chamber is mechanically extremely stable and easy to handle, unlike the case in which it is made of only ceramics.
The space between the hollow ceramic body and the fitting member may be expanded to any desired size in order to enhance the thermal insulation effect. In this case sealing performance is remarkably excellent.
Since the dimensional accuracy of the fit between the hollow space of the cylinder head and the present arrangement depends upon only the fitting member, the freedom in design of the ceramic components becomes high and only a small portion of the entire surface requires precise finishing, e.g., grinding. Since the hollow ceramic body may comprise a plurality of portions according to the present invention, the ceramic body may be formed by well-known molding methods such as extrusion molding, slip casting molding, press-molding or the like, providing a significantly excellent productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view showing one embodiment of an arrangement for thermally insulating a precombustion chamber in accordance with the present invention;
FIG. 2 is a longitudinal sectional view showing an alternative embodiment of an apparatus of the present invention which is mounted on a cylinder head;
FIGS. 3 to 5 are longitudinal sectional views showing further embodiments of the present invention; and
FIG. 6 is a perspective view showing an example of seal means applicable to the arrangement of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
(Embodiment 1)
Referring now to FIG. 1, which is a longitudinal sectional view showing an embodiment of an arrangement for thermally insulating a precombustion chamber in accordance with the present invention, the arrangement for thermally insulating a precombustion chamber 10 is generally designated by reference numeral 11. A hollow ceramic body 12 is provided with a glow plug insertion hole 12a and a fuel injection nozzle insertion hole 12b at the top thereof. The hollow ceramic body 12 is provided with a protruding collar portion 12c having a larger diameter along the periphery thereof. The hollow ceramic body 12 is also provided with a nozzle hole 12d at the bottom side thereof adjacent to a cylinder (not shown). The nozzle hole 12d extends through the bottom wall of the hollow ceramic body so that the precombustion chamber defined within the hollow ceramic body 12 communicates with a main combustion chamber (not shown) within the cylinder. Plate like packing 13, a bar-like packing 14, thermally insulating granules of inorganic material 15 and a press-fitting 16 are available as seal means between the hollow ceramic body 12 and a fitting member 17. The fitting member 17 is made of stainless steel SUS 403. The fitting member 17 is substantially of a cylindrical shape so that it completely surrounds at least the collar portion 12c of the hollow ceramic body 12. The fitting member 17 has an inner side which faces the collar portion so that a gap is defined therebetween as shown in FIG. 1. The fitting member 17 comprises a portion 17a having a larger inner diameter which extends in a direction from the collar portion 12c to the top and a portion 17b having a smaller inner diameter which faces the side of the bottom of the hollow ceramic body 12 other than the collar portion 12c.
In order to assembly the aforementioned components, the plate-like tapered packing 13 is firstly retained on a shoulder 17d formed between the larger inner diameter portion 17a and the smaller inner diameter portion 17b of the fitting member 17. The hollow ceramic body 12 is then fitted into the fitting member 17 through the larger inner diameter portion 17a. An O-ring packing 14 having a diameter larger than the spacing between the collar portion 12c and the larger diameter portion 17a is retained at the edge of the upper shoulder 12f of the collar portion 12c. A space defined by the outer surface of the upper portion 12e of the cylindrical portion of the hollow ceramic body 12 disposed above the collar portion 12c, and the larger diameter portion 17a and the O-ring packing 14 is filled with thermally insulating granules 15 of an inorganic material. After the granules have been compacted by a pressure plate (ring plate) 16, the upper end 17e of the larger inner diameter portion 17a is inwardly caulked to reduce the diameter. Due to the coaction of the plate-like tapered packing 13, the collar portion 12c, the O-ring packing 14, thermally insulating granules 15 and the pressure plate 17 which are sandwiched between the shoulder 17d between the larger inner diameter portion 17a and the smaller inner diameter portion 17b and the caulked, diameter reduced end 17e of the larger inner diameter portion 17a, an axial force is produced between the ceramic body and the fitting member, resulting in an arrangement 11 for the precombustion chamber comprising the fitting member 17 and the hollow ceramic body 12 which are firmly secured to each other.
The manner of application of the axial force necessary to tightly secure the fitting member 17 to the hollow ceramic body 12 is not limited to the aforementioned manner in which the end 17e of the larger inner diameter portion 17e is caulked and diameter-reduced. For example, a part of the larger inner diameter portion 17a may be preliminarily provided with a strip-like thickness-reduced groove 17c. After the collar portion 12c and the seal members have been loosely sandwiched by inwardly bending the end 17e of the larger inner diameter portion 17a, thermal caulking may be carried out by conducting a large electric current through the fitting member 17. By using both methods in a combined manner, the fitting member 17 may be more firmly fastened to the hollow ceramic body 12.
Although the types and combinations of the seal means are not limited to those in the aforementioned embodiment, it is preferred that the shoulder between the larger and smaller inner diameter portions and the side edge of the bottom of the collar portion facing thereto be tapered for the alignment of the hollow ceramic body and a disc-like (or tapered) packing be used for sealing the space between the tapered surfaces in the case where the smaller inner diameter portion of the fitting member 17 is formed at the bottom side. On the other hand, it is preferred that the seal member for sealing the space between the top side end of the collar portion 12c and the larger inner diameter portion 17a be an O-ring wire packing. Although sealing can be accomplished by using a single O-ring packing unlike in the aforementioned embodiment, use of the O-ring packing in combination with the thermally insulating granules of inorganic material and the press fit mitigates the axial mechanical impact on the hollow ceramic body due to elasticity of the granules.
Thermally insulating granules such as talc, magnesia, alumina, ferrite, mica powder are suitable for the inorganic thermally insulating granules.
(Embodiment 2)
Referring now to FIG. 2 which is a longitudinal sectional view showing an alternative embodiment of an arrangement 10 for thermally insulating the precombustion chamber 21 fitted into the hollow space 28a of the cylinder head, hollow ceramic body 22 is provided with a glow plug insertion hole 22a and a fuel injection nozzle hole 22b at the arched top portion thereof. The hollow ceramic body 22 is also provided with a collar portion 22c having a larger diameter at the periphery thereof and is provided with a nozzle hole 22d at the bottom thereof. The hollow ceramic body 22 of the present embodiment is different from that of embodiment 1 in that it is divided into top and bottom half portions 22' and 22", respectively, at the collar portion 22c. A plate packing 23 and an O-ring packing 24 are disposed between the hollow ceramic body 22 and a fitting member 27. The fitting member 27 is in a reverse shape to that shown in Embodiment 1. The fitting member 27 has a larger inner diameter portion 27d and a smaller inner diameter portion 27b at the inner surface thereof.
Upon assembling the components of the present arrangement, the plate packing 23 is first brought into engagement with a shoulder 27d between the larger inner diameter portion 27a and the smaller inner diameter portion 27b of the fitting member 27. The top half 22' of the hollow ceramic body 22 is fitted into the fitting member 27 through the larger inner diameter portion 27a. Then the bottom half 22" of the hollow ceramic body 22 is fitted into the fitting member 27. After the O-ring packing 24 is brought into engagement with the end of the collar portion 22c close to the cylinder, the end 27e of the larger inner diameter portion 27a is caulked to reduce the inner diameter. The fitting member 27 is fastened to the hollow ceramic body 22 to form the arrangement 21 for thermally insulating the precombustion chamber 21a. After the arrangement 21 has been fitted into a hollow space 28a of the cylinder head 28 by a conventional metal component fitting method such as press fit, shrinkage fit, the arrangement 21 is secured to the cylinder head 28 by means of a heat shield ring 29 which prevents the combustion gas from contacting with the caulked portion 27e. It is preferred to leave some clearance between the caulked portion 27e and the heat seal ring 29. Caulking of the fitting member 27 at the bottom half 22" of the hollow ceramic body 22 unlike the embodiment 1 makes it possible to carry out end surface machining of the fitting member 27 at the top thereof and provides easy axial positioning when the thermally insulating arrangement 21 is fitted into the hollow space 28a.
The glow plug 20a and the fuel injection nozzle 20b are inserted into the precombustion chamber 11a of the thermally insulating arrangement 21 secured to the hollow space 28a. In this case, it is not necessary to seal the top space defined by the ceiling of the hollow space 28a and the arched top portion of the hollow ceramic body 22 from the precombustion chamber 10.
After an engine incorporating the present arrangement was operated at 4000 rpm for 100 hours, the arrangement and the precombustion chamber was observed by lifting the cylinder head, which showed no defects at the ceramic members, no tilting, descent, indentation or deformation of the thermally insulating arrangement.
It has been found upon disassembling the arrangement 21 for thermally insulating the precombustion chamber that there was no sign of invasion of the combustion gas into the space between the inner surface of the fitting member 27 and the collar portion 22c, i.e., complete sealing was maintained.
(Embodiment 3)
Referring now to FIG. 3, which is a longitudinal sectional view showing an embodiment of an arrangement for thermally insulating the precombustion chamber in accordance with the present invention, the arrangement for thermally insulating a precombustion chamber 10 is generally designated by reference numeral 31. A hollow ceramic body 32 is provided with a glow plug insertion hole 32a and a fuel injection nozzle insertion hole 32b at the top thereof. The hollow ceramic body 32 is formed with a collar portion 32c having a larger diameter along the periphery thereof. The hollow ceramic body 32 is also provided with a nozzle hold 32d at the bottom side thereof adjacent to a cylinder (not shown). The nozzle hole 32d extends through the hollow body so that the precombustion chamber 10 defined within the hollow ceramic body 32 communicates with a main combustion chamber (not shown) within the cylinder. There are provided an annular plate packing 33 and an O-ring packing 14 as seal means between the hollow ceramic body 32 and fitting member 37.
The fitting member 37 is fitted to the outer periphery of the hollow ceramic body 32. The fitting member 37 has a stepped shoulder 37a at the inner side, which faces to the top end of the collar portion 32. A press fitting member 39 is press-fitted into a space defined by the inner side of the fitting member 37, the outer side of the hollow ceramic body extending from the collar portion 32c thereof.
In assembling the components, the annular plate packing 33 is interposed between the shoulder 37a of the fitting member 37 and the top end surface of the collar portion 32c. The hollow ceramic body 32 is fitted into the fitting member 37. The O-ring packing 34 having a larger diameter than the space distance between the inner side of the fitting member 37 and the collar portion 32c is inserted into the space between the fitting member 37 and the hollow ceramic body 32 and is retained on the end side of the collar portion 32c directed to the cylinder. The fitting member 37 is fastened to the hollow ceramic body 32 by press-fitting the press fitting member 39 therebetween to provide the arrangement 31 for thermally insulating the precombustion chamber.
It is preferred that the top end side of the collar portion 32c and the shoulder 37a facing thereto are tapered for alignment with the hollow ceramic body 32.
(Embodiment 4)
Referring now to FIG. 4, there is shown a further embodiment of an arrangement for thermally insulating the precombustion chamber of the present invention.
The thermally insulating arrangement 41 includes a hollow ceramic body 42 which is identical with the hollow ceramic body 32 of the embodiment 3 except for that the hollow ceramic body 42 is divided into a top half 42' and a bottom half 42" at the collar portion 42c. An annular plate packing 43 is retained on the top end side of the collar portion 42c similar to the plate packing 33 of embodiment 3. Thermally insulating granules of inorganic material such as talc are packed in the space defined by an end outer side of the hollow ceramic body 42 extending from the collar portion 42c towards the cylinder in order to seal the space between the inner side of the fitting member 47 and the collar portion 42c. A press fitting member 49 is press-fitted into the residual space which is not filled with the granules. Although the granular sealing material such as inorganic thermally insulating granules 44 is applicable only when the space between the inner side of the fitting member 47 and the collar portion 42c is narrow enough to be invaded by the granules (e.g., a space up to about 0.1 mm for talc etc.), it has a function to mitigate the mechanical impacts on the hollow ceramic body 42 due to its elasticity as well as to provide sealing and thermal insulating functions. If the O-ring packing 34 used in the embodiment 3 is preliminarily retained on the end side of the collar portion 42c close to the cylinder and the aforementioned space is sealed, the inorganic thermally insulating granules 44 can be packed even when the space is wide.
The arrangement 41 for thermally insulating the precombustion chamber is press-fitted into a hollow space of a cylinder head (not shown). The glow plug 20a and the fuel injection nozzle 20b are inserted into respective bores 42a and 42b in the arrangement 41.
After an engine incorporating the present apparatus was operated at 4000 rpm for 100 hours, the precombustion chamber was observed by lifting the cylinder head. It showed no defects at the ceramic members, no tilting, descent, indentation or deformation of the thermally insulating arrangement.
Upon disassembling the arrangement 41 for thermally insulating the precombustion chamber it has been found that there was no sign of invasion of combustion gas into the space between the inner surface of the fitting member 47 and the collar portion 42c so that complete sealing was maintained.
(Embodiment 5)
Referring now to FIG. 5, there is shown a further embodiment 5 of an arrangement for thermally insulating the precombustion chamber of the present invention. The arrangement 51 of this embodiment is identical with that shown in FIG. 3 except for that the seal member 53 for sealing a space between the hollow ceramic body 52 and the fitting member 55 at the side of top thereof is not a plate packing, but a bevel packing having a dogleg shaped section as shown in FIG. 6. If such a bevel packing 53 is used, alignment of the ceramic hollow body 52 with the fitting member 55 is easier when the hollow ceramic body 52 is fitted into the fitting member 55 since the hollow ceramic body 52 is readily fixed with respect to the fitting member 55 in an axial direction.
It should be noted that the embodiments hereinabove mentioned are presented for a better illustration of the present invention and not for a limitative purpose. Modifications may be carried out within the gist and the concept of the present invention herein disclosed and claimed hereinbelow. | A precombustion chamber provided with an arrangement for thermally insulating a cylinder head of an internal combustion engine from a combustion gas in the precombustion chamber comprising: (a) a hollow ceramic body which provides a precombustion chamber and is disposed within the hollow space for the precombustion chamber; (b) a hollow fitting member disposed surrounding the hollow ceramic body within the hollow space for mitigating and absorbing the stress produced between the cylinder head and the hollow ceramic body; and (c) seal means for sealing a space between the hollow ceramic body and the fitting member to provide a closed space therebetween, wherein said hollow fitting member is tightly secured to the hollow ceramic body through the seal means. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a Stirling cycle apparatus or a reverse Stirling cycle apparatus, especially to a Stirling cycle apparatus having a diaphragm which divides a piston back side room and a crank room.
2. Description of Prior Art
A conventional Stirling cycle apparatus, for example a Stirling engine, uses an operational fluid. The operational fluid is cooled or heated and is sent to the expansion cylinder or the compressor cylinder. The expansion cylinder and the compressor cylinder driven by the operational fluid rotate the crank shaft through the piston and the rod. An output shaft connected to the crank shaft supplies the rotational energy as an output power.
A conventional reverse Stirling cycle apparatus, for example a Stirling cycle cooling apparatus or a Stirling cycle compressor, has a motor to rotate the crank shaft. The crank shaft moves the expansion piston and the compressor piston through the rod. The operational fluid in the cylinder is compressed or expanded to take the heat away or to generate the heat.
In this type of Stirling cycle apparatus, a diaphragm dividing the piston back side room and the crank room is attached to the rod which connects the compressor and expansion pistons with the rod. This diaphragm prevents the oil from leak. The volume changes of the piston back side room due to a pressure change may break the diaphragm.
In order to solve this problem, two compressor pistons are placed in 180 degrees to each other and one crank pin is connected to the pistons so that the volume change at the diaphragm has a 180 degree phase difference. Further the piston back side rooms are connected to each other to prevent the volume changes. In this mechanism, however, the torque change in accordance with the movement of the compressor piston is too big and makes too much vibrations and noise. This is due to the arrangement of the two pistons in 180 degrees. The two pistons must be placed in 90 degrees to cut the torque change down. But the load to the diaphragm caused by the volume change of the piston back side room and the crank room becomes another problem. In order to reduce such load, it is easy to use a buffer tank which is connected to the upper room of the diaphragm. It is required, however, a bigger buffer tank to reduce the pressure changes small enough.
The object of the present invention is to provide a Stirling cycle apparatus having improved the above-mentioned drawbacks.
The object of the present invention is to provide a Stirling cycle apparatus has an improved simpler mechanism to reduce the pressure changes to prevent the diaphragm from breaking.
Other objects will be apparent from an understanding of the invention.
In accordance with this invention, a Stirling cycle apparatus comprises of: a cylinder, a compressor piston, an expansion piston, a crank room at the back side of the compressor and expansion pistons, a crank shaft placed in the crank room, a rod connecting the compressor piston with the crank shaft, a rod connecting the expansion piston with the crank shaft, a compressor piston back side room at the back side of the compressor piston, an expansion piston back side room at the back side of the expansion piston, a buffer connecting the compressor piston back side room with the expansion piston back side room, and a diaphragm dividing the buffer and the crank room.
In accordance with the present invention, the pressures at the compressor piston back side room and the expansion piston back side room become the same as the pressure at the buffer. Further, the diaphragm is placed at the rod between the buffer and the crank room so that the pressure changes caused by the volume change between the piston back rooms and the crank room can be absorbed by the diaphragm. The diaphragm at the rod can be moved in accordance with the movement of the rod. Thus the diaphragm is prevented from breaking due to the stress. Further more in this invention, the pressure difference between the upper side of the diaphragm and the lower side of the diaphragm is reduced by a simple mechanism. The stress to the diaphragm is also reduced to make the diaphragm life longer. It will become available to place the piston without considering the pressure changes at the piston back side room and the crank room. Thus the torque change is also reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment thereof, in connection with the accompanying drawing in which;
FIGURE is a schematic diagram of a Stirling cycle apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of a Stirling cycle apparatus is shown in FIGURE. This embodiment is a cooling device using a reverse Stirling cycle apparatus.
Expansion rooms 3, 3' are made of expansion cylinders 1, 1' and expansion pistons 2, 2'. Compressor rooms 8, 8' are made of compressor cylinders 6, 6' and compressor pistons 7, 7'. The expansion rooms 3, 3' are connected to the compressor rooms 8, 8' through a radiator, accumulators 4, 4' and heat exchangers 5, 5'. This consists a reverse Stirling cycle mechanism.
A crank shaft 10 driven by a motor 9 is connected to the compressor pistons 7, 7' and the expansion pistons 2, 2' through rods 11, 11' and 12, 12'. The compressor pistons 7, 7' reciprocate in about 90 degree delay with respect to the expansion pistons 2, 2'. At the reverse Stirling cycle mechanism, a cooling heat occurs at the expansion rooms 3, 3'. The expansion pistons 2, 2' of the reverse Stirling mechanisms operate in 90 degree phase difference. Diaphragms 16, 16' and 17, 17' divide the piston back side rooms 13, 13' and 14, 14' and the crank room 15 contains the crank shaft 10. The circumference of the diaphragms are connected to the lower end of the cylinder and the center of the diaphragms are connected to the rods 11, 11' and 12, 12'.
Buffers 19, 19' connect the compressor piston back side rooms 13, 13' and to the expansion piston back side rooms 14, 14'. Diaphragms 18, 18' divide the buffers 19, 19' and the crank room 15.
The movements of the compressor pistons 7, 7' and the expansion pistons 2, 2' change the volume of the piston back side rooms 13, 13', 14, 14' and the crank room 15. This volume changes make a pressure difference at the diaphragms 16, 16', 17, 17'. The fluid at the piston back side rooms 13, 13', 14, 14' flow into the buffers 19, 19'. The pressure differences between the buffers 19, 19' and the crank room 15 are absorbed by the diaphragms 18, 18'. This keeps the diaphragms 16, 16', 17, 17' of the rods 11, 11', 12, 12' away from the pressure so the diaphragms 16, 16', 17, 17' are in safe without any damages.
As shown in FIGURE in dotted line, a line 20 with an oil mist filter or with an absorber 21 may connect the piston back side rooms 13, 13', 14, 14' and the buffers 19, 19' with the crank room 15. If the pressure of the piston back side room drops and the pressure occurs between the crank room, the pressure is released to the crank room 15 through the line 20. This prevents the diaphragms from the excess pressure by keeping the pressure constant.
Although the invention has been described in its preferred form with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than specifically described herein without departing from the scope and spirit thereof. | A stirling cycle apparatus having a buffer connecting the compressor piston back room with the expansion piston back room. The apparatus also has a diaphragm which divides the buffer and the crank room. The buffer reduces the pressure changes between the both sides of the diaphragm so that the stress to the diaphragm can be reduced. | 5 |
TECHNICAL FIELD
The present disclosure relates generally to developing a system that uses raw machine data to classify operations of a machine, such as a bulldozer, loader, excavator, etc.
BACKGROUND
It is useful to know what operations a machine is performing for many reasons, including scheduling preventive maintenance, providing operator training, and suggesting supplemental equipment purchases, to name a few. However, short of asking an operator to specifically log every operation, which is impractical, machines used for construction, mining, logging, and others functions, do not report their activities, only the state of the machine.
U.S. Publication 2102041910 (the '910 publication) discloses a method of establishing a process decision support system that combines expert analysis and operational data to be determined if a given process is good or bad. The '910 publication fails to teach developing an operation classifier that determines a current operation of a machine based on expected operations of the machine and associated machine states.
SUMMARY
In an aspect of the disclosure, a method of developing a machine operation classifier includes i) identifying, via a user interface of a computer, an operation of a machine, ii) compiling, at the computer, a list of conditions that are associated with the operation of the machine, and repeating, at the computer, steps i and ii for one or more operations that the machine is expected to perform. The method may also include generating, via the computer, a classifier algorithm, wherein the classifier algorithm outputs the operation of the machine selected from the identified operations of the machine in response to identification of conditions in the associated list of conditions when the classifier algorithm is executed on a processor of the machine. The operation of the machine may includes the operation of one of a construction machine, a mining machine, or an earthmoving machine.
In another aspect of the disclosure, a method of creating an operation classification algorithm for a machine may include developing a catalog of operations performed by the machine, cataloging events associated with each of the operations, wherein the events include tool events, direction events, gear events, and load/power events and for each event, document one or more machine conditions associated with the event. The method may include, for each machine condition, developing a calculation used to determine the one or more conditions from one of a current machine state or a combination of current and previous machine states. The method may continue by generating a classification algorithm that monitors the one or more machine conditions and outputs a current operation of the machine using the one or more conditions to identity events associated with the operation.
In yet another aspect of the disclosure, a computer for creating a classification algorithm for a machine may include a processor, a user interface coupled to the processor, and a memory storing instructions for execution on the processor. When the instructions are executed on the processor, the computer may receive, via the user interface, information about the machine. The information may include a catalog of operations performed by the machine, one or more events associated with each of the operations, and information for determining when each of the one or more of events has occurred. Further instructions may be executed by the processor that cause the computer to generate the classification algorithm that determines when one or more events has occurred in the machine and matches the one or more events to an operation from the catalog of operations.
These and other benefits will become apparent from the specification, the drawings and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a first off-road machine;
FIG. 2 is an illustration of a second off-road machine;
FIG. 3 is an illustration of a third off-road machine;
FIG. 4 is a block diagram of an exemplary controller for an off-road machine;
FIG. 5 is a block diagram of an exemplary computer adapted to generate machine operation classifier algorithms;
FIG. 6 illustrates an exemplary input chart for identification of events and operations; and
FIG. 7 is a flow chart of an exemplary method of generating machine operation classifier algorithms for a particular machine.
DESCRIPTION
A machine operation classifier observes characteristics of the operation of a machine and decides what operation is being performed. The classifier then logs the operations for later use in analyzing performance, operator training, maintenance scheduling, and more. However, the development of the operation classifier is complicated. Dozens of measurements are available from the machine, from direct measurements such as engine RPM and hydraulic cylinder pressures, to indirect measurements such as drawbar pull or tool position.
FIGS. 1-3 illustrate different machines with exemplary operations that each perform and some of the characteristics that may be observed to determine an operation.
FIG. 1 is an illustration of an off-road machine, specifically, an excavator 100 . The excavator 100 may have an engine 102 , tracks 104 or wheels for propulsion, and an implement 106 for use in performing a work function, in this case digging. The implement 106 may include a boom 108 and a boom cylinder 110 used to raise and lower the boom 108 . The implement 106 may also include a stick 112 that extends and retracts using a stick cylinder 114 and may further include a tool, such as a bucket 116 , the that rotates using a bucket cylinder 118 . In operation, the excavator 100 may use combinations of cylinder positions to engage the bucket 116 into a dig site to remove material and then to maneuver the bucket 116 to dump the material away from the dig site or into a dump truck or the like.
At a high level, the basic operations of the excavator 100 may include ‘travel’ using the tracks 104 , ‘dig,’ and ‘dump.’ At a lower level, the excavator 100 may also perform functions including boom raise and lower, stick reach and pull, as well as bucket rotate in and bucket rotate out. Each of these operations may be accomplished by one or a combination of events, including tool events, direction events, gear events, and power events. The identification of events may include “raw channel” information, such as tool commands, ground speed, gear settings, engine speed, fuel burn rate, or tool position. This raw channel information may be supplemented by “derived channel” information such as developing power (e.g. drawbar pull) using, for example, a gear setting and engine speed. Derived channel information may also be used when certain raw channel information is not available such as tool position. For example, tool position may be derived by integrating raw tool commands over time and incorporating upper and lower limits for tool position. That is, a boom up command can be integrated over time to follow movement of the boom. However, because the boom up command may be held beyond the time the boom 108 reaches its maximum height, a saturation limit must be applied so that the calculated position does not track beyond the actual position.
Information from the raw channel or derived channel data may be used to determine certain true/false events, such as whether the tool is active or inactive or whether a tool is engaged or disengaged. To determine if a particular operation is being carried out, several true/false events such as “stick extended=true” and “tool active=true” may be evaluated in combination.
Each event may have its own condition and tolerances. For example, to determine whether a tool active event is true or false a current tool command may be compared against a predetermined active value in view of a tolerance for the tool command.
Other events can be developed using information such as cylinder position for the various hydraulic cylinders, cylinder pressures can be used to determine whether a tool is loaded or unloaded, and groundspeed calculations using engine revolutions per minute (RPM) and corresponding transmission or torque converter settings may be used to determine power events. Other observable conditions may be associated with these true/false events such as change of engine RPM, change in hydraulic cylinder position, change in cylinder pressure, etc.
Exemplary operations and events are illustrated in Table 1 and Table 2 below.
For example, when the excavator 100 is performing a traveling operation the associated conditions may include: the boom 108 up, the stick 112 in, implement controls 107 neutral, and the transmission in a high gear, such as gear 3 or above. In another example, when the excavator 100 is performing a dig operation a more complex set of conditions may be evaluated to automatically determine the dig operation. Several true/false events may be defined for the operation. For example, “tool active=true,” “tool engaged=true,” and “high load/power=true” may be sufficient to infer that a dig operation is occurring. Negative events, such as “direction forward=false” may also be used to infer operations.
In order to define an event as being true or false, a value for a condition may be defined, with a given tolerance for the condition. The tolerance may provide for some hysteresis so that the state changes are damped and so that when alternate conditions, such as tool engaged and tool disengaged, are both true, the machine operation classifier algorithm may be able to infer that the machine is in a transition state. For example, a tool active event may be identified when the boom 108 may be down more than 20% from its fully up position with a 5% tolerance, the stick 112 may be out more than 40% from its fully in position with a 5% tolerance, and the bucket 116 may be rotated more than 40% from its fully in position with a 10% tolerance. Once some defined set of initial conditions are met, subsequent changes in conditions may be evaluated to see if the boom 108 is adjusted up or down (i.e., tool active), the stick 112 is drawn in, or the bucket 116 is rotated in, that is, using a derivative of respective cylinder positions. Hydraulic pressures for the stick cylinder 114 and the bucket cylinder 118 may be monitored to watch for pressure increases associated with engaging a work surface 119 .
Once instantaneous conditions for an operation are developed for a machine, such as the excavator 100 , a computer programmed for the special function of developing a classification algorithm may be operated to generate the classification algorithm for a particular machine that classifies operations of the machine by evaluating the instantaneous conditions or the time series of conditions associated with that operation. The computer program that generates the algorithm is discussed in more detail below. One goal of the process is to select the minimum set of conditions and/or events required to identify an operation.
FIG. 2 illustrates a grader 120 having a motor 122 , a steering wheel 124 , blade control 126 , a blade 130 , a blade angle cylinder 132 and a height cylinder 134 . The grader 120 may include steerable wheels 136 . The grader 120 is configured to scrape and level a worksite 138 using the blade 130 .
As with the excavator 100 above, the grader 120 may operate in several modes including a transport mode and a grading mode. The transport mode may be identified by conditions including groundspeed being above a certain threshold and the position of the height cylinder 134 being retracted beyond a threshold position. The grading mode may be identified by characteristics including blade position and drawbar pull, for example measured by strain gauges on the drawbar 140 .
FIG. 3 illustrates a wheel loader 150 with a motor 152 , operator control 154 , a boom 156 , boom cylinder 158 , and bucket 160 . The bucket 160 may be rotated between a load position and dump position via a bucket arm 162 and a corresponding bucket cylinder 164 .
Operations of the wheel loader 150 may include moving to a load point, loading, moving to a dump point, dumping and scraping. Each may be characterized by events associated with that operation. For example, loading may be characterized by lowering the boom 156 beyond a percentage of full height, such as 50%, rotating the bucket 160 back within a percentage of fully up (or racked), such as 40%, and being engaged in forward motion. When this action is followed by retracting the bucket 160 to fully up and raising the boom 156 , the load operation may be confirmed.
Dumping may also have a sequence of events that characterize the operation, such as raising the boom 156 and fully dumping the bucket 160 , either at once or in stages. The ability to measure the bucket load improves the ability to identify operations in that a bucket full of material is indicative of having completed a load operation and an empty bucket is indicative of having completed a dump operation. Bucket load may be directly determined from a raw condition of the loader 150 , such as a mass sensor (not depicted) on the boom 156 . Alternatively, the bucket load determination may use a derived condition from other measurements such as boom cylinder pressure and bucket cylinder pressure.
One scraping operation may involve fully lowering the bucket 160 and lowering the boom 156 so that the bottom edge of the bucket 160 is nearly vertical to the work surface and then moving backward to level the work surface. By recognizing these conditions, the scraping operation may be identified.
FIG. 4 illustrates a controller 200 that may be used in a machine, such as excavator 100 or any of the other machines discussed above, to execute a classification algorithm that identifies a machine operation based on observed conditions in the machine 100 . Controller 200 may include a processor 202 coupled to a memory 204 via a data bus 206 . Also connected to the data bus 206 may be a number of sensor inputs, that may include but is not limited to, a torque or drawbar pull sensor 208 , a groundspeed sensor 210 , a track speed sensor 212 , a slope sensor 214 , or a gear sensor 216 . Also connected to the data bus 206 may be outputs such as a driver to provide information to an operator display 218 or an interface 220 to provide log data to an local device, such as a memory card, or via a network connection (not depicted) to an external device.
The memory 204 may be any of a number of physical hardware memories including separately or in combination hard disk drive, a solid-state memory, flash memory, removable storage media, or the like, but does not include propagated media such as carrier waves. The memory 204 may include an operating system 222 and associated utilities 224 used, for example, for set up and diagnostics. The memory 204 may also include the classification algorithm 226 that is executed by the processor 202 to collect data from the various inputs and generate a log of operations. The classification algorithm 226 may include performance calculations 228 such as those discussed above to identify certain events based on characteristics of the machine 100 . The classification algorithm 226 may also include, among other routines, operating data and/or lookup tables 230 used to store available operations, events associated with each of the operations, and conditions associated with the various events.
FIG. 5 illustrates a computer 250 that may include a processor 252 and a memory 254 coupled by a data bus 256 . The computer 250 may include a variety of user interface elements including, but not limited to, a display or touch screen 258 , a keyboard and/or mouse 260 , a microphone 262 , a camera 264 , and speakers 266 . The computer 250 may also include a network interface 268 used to communicate via a local or wide area network (not depicted). As above, the memory 254 may be any of a number of physical hardware memories including separately or in combination hard disk drive, a solid-state memory, flash memory, removable storage media, or the like, but does not include propagated media such as carrier waves.
The memory 254 may include an operating system 272 and utilities 274 . The memory may also include an algorithm program 276 that receives input about operations of a machine as well as various events and associated conditions. The operation of the algorithm program 276 as discussed in more detail with respect to FIG. 6 . Briefly, while the algorithm program 276 is executed by the processor 252 various inputs are received including a catalog of operations 278 , a catalog of events 280 and their associated conditions, and a corresponding classification algorithm 282 is output in stored for use in a particular machine, such as machine 100 . The algorithm program 276 may be used to generate multiple classification algorithms for various machines as illustrated by a second operations catalog 284 , a second event catalog 286 , and a second classification algorithm 288 .
FIG. 6 illustrates an exemplary input chart 300 for identification of events and operations. The chart 300 illustrates how a user may interface with the algorithm program 276 to identify characteristics associated with various operations so that the algorithm can generate the code necessary to identify and log the operations of interest. The chart 300 shows exemplary data collected over time for a bulldozer displayed in vertically arranged set. Other data sets may be used depending on the piece of equipment and the exact operations being characterized.
FIG. 6 shows four representative data series: ground speed, power (i.e., drawbar pull), blade raise (i.e., blade tool active), and blade angle (i.e., blade angle active).
A user may create a drop down list of the possible operations/segments for the particular machine, in this case, Load, Carry, Spread, and Reverse. Other machines may have different lists of possible operations. Next, the user may select one of the operations in the drop down list to let the system know which operation logic will be created. The user may then specify whether the parameter that is being specified should be a minimum or a maximum. Finally, the user may move the cursor over one of the time series plots and sees a dynamic horizontal line, e.g., line 302 for ground speed, line 304 for power, line 306 for blade raise, and line 308 for blade position. Each line 302 , 304 , 306 , 308 may be separately selected and adjusted by dragging with a cursor. When the user has decided on the threshold value for a given channel, the user may click an input button to accept the location. The system may then record, for example, “Carry if PWR_alg>0.4” assuming minimum was previously selected. More interface options allow selection of “and” or “or” criteria to compose multiple logic conditions.
The user may also add labels 310 and 312 via the user interface that allow correlation of operations to the data series for ease of identification. Sample pseudo-code output associated with the completed process are shown below.
INDUSTRIAL APPLICABILITY
The ability to generate classification algorithms for various machines by capturing the operations the machine performs and events associated with each operation reduces the time and effort required to create classification algorithms and may also improve the quality of the classification algorithms by generating consistent code from a human readable set of inputs.
FIG. 7 is a flow chart of an exemplary method 330 of generating machine operation classified algorithms for a particular machine 100 . At block 332 an operation performed by the machine 100 may be identified. A list of exemplary operations is depicted in Table 1 below. For example, dig, carry, and spread are typical of bulldozer operations where the blade digs material, carries the material to a point at the worksite, and spreads the material at the new location.
At block 334 , events associated with the operation may be identified. The events may include tool events, direction events, gear events and load or power events. As discussed above, events may be true/false evaluations related to conditions in the machine 100 . At block 336 , for each event one or more conditions associated with that event may be identified. The condition may be defined as a function of raw data (see, e.g. Table 4 below) or may be a function of derived information, an example of which is shown in Table 3 below. Derived information may be calculated using one or more raw data elements.
At block 338 for each condition a calculation is developed that evaluates conditions in the machine for current and/or past machine conditions, whether raw or derived, and generates an output corresponding to the inferred operation being performed. In one embodiment, the calculation may be an actual calculation or may be a programmatic device such as case statements known in some programming languages.
For example, forward travel may be described in pseudo-code as
blade_tool_active == 0
AND
PWR < 0.2 OR steer_avg > 0.2
AND
ground_speed_mps > 0
where PWR is drawbar pull, steer_avg is steering average displacement, and groundspeed is in meters per second.
Similarly, the load operation of a bulldozer may be expressed in pseudo-code as:
ALWAYS (the following must always be true for the operation)
gear > 0 AND steer < 0.3 AND 0 < ground_speed_mps < 1.5
BEGIN IF (the following triggers the operation to start):
PWR_deriv > 0.02 OR eng_spd_deriv < −25
AND
PWR > 0.1 AND
blade_lower_flag > 0 AND
blade_tool_active == 1 AND
gear > 0 AND
steer_avg < 0.3
END IF (the following triggers the operation to stop)
PWR_deriv > 0.075
where steer is the steering angle and PWR_deriv is the first derivative of drawbar pull.
If additional operations are available to be included in the classification algorithm execution returned to block 332 and the process is repeated for the additional operation. If no more operations are to be included in the classification algorithm, execution may continue at block 340 where the classification algorithm 226 used for installation into the controller 200 of the machine 100 may be generated. The classification algorithm 226 may be stored in memory 254 of the computer 250 and transmitted to the machine 100 via the network interface 268 or may be transferred using a known removable memory, such as a flash drive.
Tables 1-4 illustrate representative values. The actual values for a particular machine may be less than shown or may have values not specifically illustrated here.
TABLE 1
Operations
Idle
Travel
Reverse
Dig/Load
Carry/Haul
Dump/Spread
Compact
Grade
Ditch
TABLE 2
Direction
Tool Events
Events
Gear Events
Load/Power Events
Tool Active
Forward
High Gear
Low Load/Power
Tool Inactive
Stopped
Low Gear
High Load/Power
Tool Engaged
Reverse
Forward Gear
High Fuel Burn
Tool Disengaged
Reverse Gear
Low Fuel Burn
Specific Tool
Neutral
Position
Tool High Pressure
Tool Low Pressure
Note:
Events are True or False
TABLE 3
Derived
Integrated Tool Command Gives Tool/Cyl
Position
Derivative of Cylinder Position
Derivative of Motor Position
Frequency of Tool Command
Drawbar-Pull
Pull-Weight Ratio
Normalized Drawbar-Pull
Normalized Tool Command (−1 to 1)
Machine Power
Tool Force
TABLE 4 Raw Cylinder Position Motor Position Tool Position Tool Positve Command Tool Negative Command Tool Signed Command Fuel Burn Rate Tool Pressure Signed Ground Speed Ground Speed Engine Speed Transmission Input Speed Gear Transmission Gear Ratios Fixed Drivetrain Ratios
In accordance with the provisions of the patent statutes and jurisprudence, exemplary configurations described above are considered to represent a preferred embodiment of the invention. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. | A process for developing machine classification systems includes using human experts to associate expected operations with various machine states including drawbar pull, tool position, tool commands, gear, and ground speed, among others, to create a classification system that can be used in a particular machine. The classification system operates in real time to infer operations such as dig, dump, travel, and push from machine state inputs and logs the operations for use in operational analysis and maintenance of the machine. | 6 |
[0001] This application is a continuation-in-part of U.S. Ser. No. 11/036712, filed Jan. 14, 2005, now pending; which is a continuation of U.S. Ser. No. 10/218962, filed Aug. 14, 2002, now U.S. Pat. No. 6,906,009, the disclosure of which is incorporated by reference in their entirety herein.
[0002] This invention relates to a novel drilling fluid composition and use thereof in drilling wells for petroleum and natural gas.
BACKGROUND
[0003] In oil drilling operations, a drilling fluid is circulated downwardly through a drill string to cool and lubricate the drill string, suspend the cutting removed from the well bore and to keep out formation fluids. The drilling fluid containing the suspending cuttings are further circulated upwardly through the annulus between the drill string and wall of the well bore to the surface, where the cutting are separated and the recycled drilling fluid is circulated down the bore. Drilling fluids, also known as drilling muds, may be oil- or water-based. Both water-based and oil-based drilling fluid systems are known. The more economical water-based systems are used when practicable with oil-based systems being used where increased lubricity at the drilling head is desirable or when traversing formations which would be adversely affected by a water-based system, such as water soluble shale formations.
[0004] A conventional oil-based drilling fluid (mud) generally comprises an oil fluid vehicle, such as a diesel oil, emulsifiying agents, such as alkaline soaps of fatty acids, wetting agents or surfactants, such as dodecylbenzene sulfonate, water, generally as a NaCl or CaCl 2 brine, and a viscosifying agent, such as an amine treated clay. Oil-base fluids may have an aromatic or aliphatic oil, or a mixture of oils, as the continuous phase. These oils may include diesel, mineral or synthetic (PAO, esters, ether) oil. They may be comprised entirely of oil or, more commonly, may contain water ranging from 5% to upwards of 50-60%. In the latter case, water becomes the internal phase, is emulsified into the oil as a heterogeneous fine dispersion, and the resulting system is referred to as an oil-based or oil-invert emulsion fluid.
[0005] A water-based drilling fluid comprises a viscosifying agent, generally a clay such as a solid phase bentonite attapulgite or sepiolite, and a water fluid vehicle. In addition, salt or salt water can be added to the components of the drilling fluid to prepare a salt water based drilling fluid. Numerous different additives to this drilling fluid are also employed to control viscosity, yield point, gel strength (thixotropic properties), pH, fluid loss, tolerance to contaminants such as salt and calcium carbonate, lubricating properties, filter caking properties, cooling and heat transfer properties, and tolerance to inactive solids such as sand and silt or active native mud making clays such as smectites, illites, kaolinites, chlorites, etc. Clays are not usually used as the sole viscosifying agent and typically organic water-soluble polymers such as starch, carboxymethylcellulose, natural gums or synthetic resins are used in conjunction with clays. These polymers also aid the clay component of the drilling fluid to serve as a filtration aid to prevent or retard the drilling fluid from being lost into the formation.
[0006] A number of drilling fluid formulations have been described. For example, U.S. Pat. No. 3,726,850 discloses a lignin dispersing agent for dispersing clays, and the like. The lignin dispersing agent is reported to have utility in both alkaline and acidic media. A relatively low viscosity aqueous silicate solution is disclosed in U.S. Pat. No. 3,746,109, and is reported to be particularly useful in drilling through shale formations. U.S. Pat. No. 4,799,549 discloses a stable, gel-forming microemulsion comprising an aqueous solution of an alkali metal silicate, a gelling reagent, and a surface-active agent (surfactant). This composition is reported to be useful for permanent or reversible plugging or clogging of subterranean formations. Also, U.S. Pat. No. 5,374,361 discloses a composition for cleaning out cased wellbores, and the like, using a fluid that includes a caustic alkyl polyglycoside surfactant formulation. This formulation is reported to be more biodegradable than previous detergent systems. A further additive encountered in aqueous drilling fluids is a metal compound, such as that described in U.S. Pat. No. 5,399,548, or a derivative of a metal compound such as a hydroxy-aluminum compound provided in a polymer, such as disclosed in U.S. Pat. No. 4,045,357. U.S. Pat. No. 5,333,698 also discloses a drilling fluid additive in combination with a white non-toxic mineral oil.
[0007] Although oil- and water-based drilling fluids are widely used, they require large, complex pumps to circulate the fluid down the drill string and up the annulus of the well bore. As the drill is operated, the resulting cuttings from the drill bit are suspended in the drilling fluid, thereby increasing the density and further increasing the pumping costs. In offshore well the hydrostatic pressure put additional strain on the pumping equipment and further increase the pumping costs. These cost associated with use and maintenance of these pumps contribute significantly to the costs of oil drilling operations. Further, the increased pressures and loads on the pumps make it difficult to maintain the pressure of the drilling fluid in the optimal range; between that of the pore pressure and the fracture pressure.
[0008] Several methods have been proposed to reduce the costs and overcome the problems associated with pumping drilling fluids. Shell E&P has introduced the Shell Subsea Pumping System (SSPS) whereby the drilling fluid is processed, cuttings removed and discharged at the seafloor, and gas separated prior to being pumped back to the surface. Conoco has developed a dual gradient system called Subsea Mudlift in which the drilling mud is removed from the riser with triplex pumps at the seafloor, and is then filled with seawater to reduce the riser load. Another approach called DeepVision, by Baker-Hughes and Transocean Sedco Forex uses centrifugal pumps to separate the mud at the seafloor and send it to the surface.
[0009] Some well operators have used a gas injection system to reduce the density of the drilling mud. In this system a gas such as nitrogen is added to the drilling fluid, which is circulated in the conventional manner. However due to the compressible nature of gas, large volumes and high pressures are required to maintain a gas phase in the mud, increasing the complexity and cost of the system and maintaining the appropriate pressures in the well bore. Mud/gas systems have shown a tendency to foam at the reduced pressures encountered as the mud/gas system ascends the well bore or riser causing fluid handling problems. In addition, small amounts of oxygen in the injected gas have led to corrosion problems.
[0010] To overcome the problems associated with gas injections systems, the use of hollow microspheres has been proposed. Hollow microspheres, being relatively incompressible, do not require the high pressures and associated pumps necessary with gas injection and the addition of microspheres will not lead to the foaming problems. However, improperly handled, and the size shape, density and particle size distribution can provide a nuisance dusty environment. Further, the microspheres can be difficult to efficiently separate and recycle from the drilling fluid, adding cost and complexity to their use.
SUMMARY OF THE INVENTION
[0011] The present invention provides a drilling fluid composition comprising a drilling fluid vehicle, which may be oil- or water-based, and a composite microsphere component. The microspheres of the composite microsphere component may comprise any hollow microspheres of glass, ceramic or plastic that may be added to the drilling fluid (with other components of the drilling fluid known in the art) to reduce the density thereof. Generally the composite microsphere component is added to the drilling composition in amounts sufficient to reduce the density at least 15%, preferably at least 20% and most preferably at least 30%. In one embodiment, the microsphere component is added in amounts sufficient to reduce the density of the mud to about that of the ambient seawater, or about 8 to 13 lbs/gallon (5.2 to 7.5 kg/L). In another embodiment, the microsphere component may comprise 25 to 50 volume percent of the drilling fluid composition. Such reduction in the density of the drilling fluid greatly reduces the pressures required to raise the drilling fluid to the surface, and reduces the associated pumping costs.
[0012] The composite microsphere component comprises a composite of microspheres and a polymeric resin. The composite microsphere component may be of any suitable size and shape. The composite may comprise pellets having a continuous polymeric phase having the microspheres dispersed therein, or the composite microsphere component may comprise an agglomerate of microspheres bound together by a discontinuous phase of polymeric resin. The polymeric resin may be a thermoplastic or thermoset resin. Composites having an intermediate structure between pellets and agglomerates are also contemplated.
[0013] Pellets comprising a continuous phase of polymeric resin generally comprise 20 to 75 weight % microspheres in the polymeric resin binder. The pellets may range in size from 200 to 4000 micrometers and have densities in the range of 0.4 to 1.0 g/cm 3 . Agglomerates comprise sufficient polymeric resin to bind a plurality of microspheres in randomly shaped composite particles of about 200 to 4000 micrometers and having densities of 0.4 to 0.7 g/cm 3 . Generally the agglomerates comprise 40 to 90 weight % of the microspheres. Microsphere composites having sizes in excess of about 7 mm may contribute to pumping problems.
[0014] The compressive strength required of the composite microsphere component used in drilling applications is dictated by the depth of water at which it will be employed: at shallow depths, the compressive strength of microsphere component does not have to be high, but at very great depths under the sea, the hydrostatic pressure exerted on the microsphere component becomes enormous, and the microsphere component should have very high resistance to compression (high compressive strengths). Hollow microspheres, because of their spherical form, provide resistance to compression equally from all directions (isotropic compressive strength), and are ideally suited for this application. Generally, the microsphere component has a collapse strength of at least 4000 psi (27.6 MPa), preferably at least 5000 psi (34.5 MPa) to provide an essentially incompressible density-reducing additive, in contrast to conventional gas-injection processes.
[0015] For underwater applications, the microsphere component should have sufficient hydrolytic stability, and the resin type is chosen accordingly. Preferred resins exhibit excellent hydrolytic stability, and in addition, offer outstanding compressive strengths. Strong resins and strong low-density hollow glass microspheres can be advantageously used to meet the stringent requirements of deep water drilling applications.
[0016] The present invention also provides a method of drilling comprising the step of circulating a drilling fluid down a drill string and up an annulus between the drill string and bore hole, and introducing a microsphere component to said drilling fluid in an amount sufficient to reduce the density thereof. The method may further comprise the step of separating the composite microsphere component from the drilling fluid composition and drill cuttings and the drilling fluid is returned to the surface. To facilitate separation, the microsphere component is preferably at least 200 micrometers in size.
[0017] The present invention also provides a method of reducing the density of the drilling fluid composition by adding a composite microsphere component to the drilling fluid composition in amounts sufficient to reduce the density at least 15%, preferably at least 20% and most preferably at least 30%. In one embodiment, the microsphere component is added in amounts sufficient to reduce the density of the mud to about that of the ambient seawater, or about 8 to 13 lbs/gallon (5.2 to 7.5 kg/L).
[0018] The invention provides a reduced density drilling fluid composition and method of drilling that advantageously reduces the density of the fluid and reduces costs associated with pumping. The invention uses conventional drilling and pumping equipment, requires no sea floor based pumps and may be easily pressure-controlled to maintain the pressure of the fluid to that of the ambient water pressure. More specifically, the pressure of the fluid may be maintained between fracture pressure and the pore pressure of the well to avoid fracturing the well formation and/or reduce the infiltration of water (or other fluids) from the pores of the well formation.
[0019] Advantageously the use of a composite microsphere component overcomes problems inherent in gas-injection processes by providing an essentially incompressible additive that may be used to reduce the density of a drilling fluid. The composites also allow one to specifically tailor the density, strength and size of the additive to the specific well drilling requirements and facilitates separation due to the larger size (as compared to unitary microspheres).
DETAILED DESCRIPTION
[0020] The microspheres used in the composite microsphere component may be any type of hollow spheres that are known to the art. The microspheres are preferably made of glass, but may be made be polymeric, ceramic or other materials known to the art, provided the microsphere component has sufficient physical properties to withstand the severe conditions encountered in well drilling, including collapse strength, hydrolytic stability, size, density and compatibility with polymeric resins.
[0021] Useful microspheres (of the composite) are hollow, generally round but need not be perfectly spherical; they may be cratered or ellipsoidal, for example. Such irregular, though generally round or spherical, hollow products are regarded as “microspheres” herein.
[0022] The microspheres of the composite are generally from about 5 to 1000 micrometers in diameter, and are preferably 50 and 500 micrometers in diameter. Microspheres comprising different sizes or a range of sizes may be used. Where the microsphere component comprises a composite of microspheres and a resin, for example in the form of an agglomerate or a pellet, the size of the unitary microspheres is less significant since the composite particle may be sized appropriately to facilitate separation and recovery.
[0023] As the microspheres are subjected to high pressures in a well, the microspheres should have a collapse strength in excess of the anticipated pressures. Generally the microsphere component should have a burst strength in excess of 4000 psi (27.6 MPa), preferably in excess 5000 psi (34.5 MPa) as measured by ASTM D3102-78 with 10% collapse and percent of total volume instead of void volume as stated in the test.
[0024] The density of the microspheres may vary from about 0.1 to 0.9 g/cm 3 , and is preferably in the range of 0.2 to 0.7 g/cm 3 . When a microsphere composite is used, the agglomerate having a discontinuous phase of polymeric resin may have densities in the range of 0.4 to 0.7 g/cm 3 , and composite pellets having a continuous phase of polymeric resin, may have densities in the range of 0.4 to 1.0 g/cm 3 .
[0025] Glass microspheres have been known for many years, as is shown by European Patent 0 091,555, and U.S. Pat. Nos. 2,978,340, 3,030,215, 3,129,086 3,230,064, and U.S. Pat. No. 2,978,340, all of which teach a process of manufacture involving simultaneous fusion of the glass-forming components and expansion of the fused mass. U.S. Pat. No. 3,365315 (Beck), U.S. Pat. No. 4,279,632 (Howell), U.S. Pat. No. 4,391,646 (Howell) and U.S. Pat. No. 4,767,726 (Marshall) teach an alternate process involving heating a glass composition containing an inorganic gas forming agent, and heating the glass to a temperature sufficient to liberate the gas and at which the glass has viscosity of less than about 104 poise.
[0026] Useful glass microspheres have a density of at least 0.1 gram per cubic centimeter, which is equivalent to a ratio of wall thickness to bubble diameter of about 0.029. Density is determined (according to ASTM D-2840-69) by weighing a sample of microspheres and determining the volume of the sample with an air comparison pycnometer (such as a AccuPyc 1330 Pycnometer or a Beckman Model 930). Higher densities can produce higher strengths, and densities of 0.5 or 0.6 g/cm 3 or more are preferred for some uses. The microspheres generally have an average diameter between about 5 and 1000 micrometers, and preferably between about 50 and 500 micrometers. Size can be controlled by the amount of sulfur-oxygen compounds in the particles, the length of time that the particles are heated, and by other means known in the art. The microspheres may be prepared on apparatus well known in the microspheres forming art, e.g., apparatus similar to that described in U.S. Pat. Nos. 3,230,064 or 3,129,086.
[0027] One method of preparing glass microspheres is taught in U.S. Pat. No. 3,030,215, which describes the inclusion of a blowing agent in an unfused raw batch of glass-forming oxides. Subsequent heating of the mixture simultaneously fuses the oxides to form glass and triggers the blowing agent to cause expansion. U.S. Pat. No. 3,365,315 describes an improved method of forming glass microspheres in which pre-formed amorphous glass particles are subsequently reheated and converted into glass microspheres. U.S. Pat. No. 4,391,646 discloses that incorporating 1-30 weight percent of B 2 O 3 , or boron trioxide, in glasses used to form microspheres, as in U.S. Pat. No. 3,365,315, improves strength, fluid properties, and moisture stability. A small amount of sodium borate remains on the surface of these microspheres, causing no problem in most applications. Removal of the sodium borate by washing is possible, but at a significant added expense; even where washing is carried out, however, additional sodium borate leaches out over a period of time.
[0028] Hollow glass microspheres are preferably prepared as described in U.S. Pat. No. 4,767,726 (Marshall), incorporated herein by reference, due to the greater hydrolytic stability. These microspheres are made from a borosilicate glass and have a chemical composition consisting essentially of SiO 2 , CaO, Na 2 O, B 2 O 3 , and SO 3 blowing agent. A characterizing feature of the microspheres resides in the alkaline metal earth oxide:alkali metal oxide (RO:R 2 O) ratio, which substantially exceeds 1:1 and lies above the ratio present in any previously utilized simple borosilicate glass compositions. As the RO:R 2 O ratio increases above 1:1, simple borosilicate compositions become increasingly unstable, devitrifying during traditional working and cooling cycles, so that “glass” compositions are not possible unless stabilizing agents such as Al 2 O 3 are included in the composition. Such unstable compositions have been found to be highly desirable for making glass microspheres, rapid cooling of the molten gases by water quenching, to form frit, preventing devitrification. During subsequent bubble forming, as taught in aforementioned U.S. Pat. Nos. 3,365,315 and 4,391,646, the microspheres cool so rapidly that devitrification is prevented, despite the fact that the RO:R 2 O ratio increases even further because of loss of the relatively more volatile alkali metal oxide compound during forming.
[0029] These microspheres have a density ranging from 0.08 or less to about 0.8 g/cc, the less dense products being more economical per unit volume. Glass microspheres having a higher density are, however, particularly useful in the present invention where an inexpensive and comparatively lightweight microspheres having high resistance to crushing is desired. These microspheres, in which the chemical composition, expressed in weight percent, consists essentially of at least 70% SiO 2 , 8-15% RO, 3-8% R 2 O, 2-6% B 2 O 3 , and 0.125-1.50% SO 3 , the foregoing components constituting at least about 90% (preferably 94% and still more preferably 97%) of the glass, the RO:R 2 O weight ratio being in the range of 1.2-3.5.
[0030] Preparation of hollow, ceramic microspheres by spray drying is taught in U.S. Pat. No. 4,421,562. U.S. Pat. No. 4,637,990 describes hollow, ceramic, porous microspheres prepared by a blowing technique. The resultant ceramic microspheres have diameters of 2000 to 4000 micrometers.
[0031] U.S. Pat. No. 4,279,632 discloses a method and apparatus for producing concentric hollow spheres by a vibration technique on extruded materials to break up the material into individual, spherical bodies. This method is useful with low melting point material such as glass or metal which is fluid at elevated operating temperatures.
[0032] Hollow ceramic balls prepared by a combination of coating, sintering, and reduction are disclosed in U.S. Pat. No. 4,039,480; however, the process is complex, and the balls so obtained are large (e.g., 5 by 7 mesh size which is 2.79 to 3.96 millimeters).
[0033] Ceramic metal oxide microspheres prepared by impregnating hollow, organic resin microspheres with a metal compound and firing to remove adjuvants is disclosed in U.S. Pat. No. 3,792,136. The resultant hollow microspheres generally have large diameters of 50 micrometers to 10 millimeters (mm) and in one example, when the average diameter was 3 mm, the wall thickness is disclosed to be 17 micrometers.
[0034] U.S. Pat. No. 2,978,340 describes inorganic microspheres prepared from a fusion (melt or vitreous) process using a gassing agent. The product is not uniform in size, and the microspheres are not all hollow.
[0035] Hollow ceramic spheres of low density may be prepared by the process taught in U.S. Pat. Nos. 4,111,713, and 4,744,831, which comprises
[0036] (A) tumbling together and thoroughly mixing (1) solidifiable liquid globules comprising a thermally fugitive organic binder material and a source of void-forming agent adapted to evolve as a gas and convert the liquid globules to a hollow condition and (2) a mass of minute discrete free-flowing inorganic heat-sinterable parting agent particles selected from metals, metalloids, metal oxides and metal salts that are wetted by, and at least partially absorbed into, the liquid globules during the tumbling action; sufficient parting agent particles being present so that any portion of liquid globules uncovered by parting agent particles tumble against discrete unabsorbed parting agent particles;
[0037] (B) providing conditions during the tumbling action, and tumbling for a sufficient time, for the void-forming agent to evolve as a gas and form a central interior space within the liquid globules and for the thus-hollowed liquid globules to solidify;
[0038] (C) collecting the converted globules after they have solidified to a shape-retaining condition; and
[0039] (D) firing the hollow spheres to first bum out the organic binder, and to then sinter the parting agent particles to form hollow shape-retaining spheres.
[0040] Another useful ceramic microsphere is taught in U.S. Pat. No. 5,077,241 (Moh, et al.) which comprises microspheres consisting essentially of at least one of a non-oxide component (or phase) and an oxide component (or phase), each microsphere having a ceramic wall and a single central cavity, the microspheres having diameters in the range of 1 to 300 micrometers and wall thicknesses of less than 10 percent of the diameter of the microspheres. Such ceramic microspheres may be prepared by
[0041] (1) providing a mixture containing a ceramic sol precursor and a volatile liquid, the volatile liquid being referred to herein as bloating agent,
[0042] (2) adding the above mixture, preferably as droplets, at a suitable rate and manner to a provided bubble promoting medium maintained at a suitable temperature to allow formation of green hollow microspheres; preferably the bubble promoting medium is a liquid such as an aliphatic alcohol, e.g. oleyl alcohol, or a long chain carboxylic acid ester such as peanut oil, or mixtures thereof, or mixtures of oleyl alcohol with other vegetable oils or vegetable oil derivatives,
[0043] (3) isolating the green microspheres, preferably by filtration, and
[0044] (4) firing the green microspheres, optionally mixed with an agglomeration preventative agent to provide a source of carbon, in air for oxide containing ceramic microspheres or in an inert or reducing atmosphere for non-oxide containing microspheres, and at a range of temperature sufficient to convert the green microspheres into an oxide or non-oxide containing ceramic.
[0045] Useful polymeric microspheres may be prepared by the general method of polymerization of polymeric particles having a minor amount of a volatile blowing agent dissolved within the particles which expands on heating. U.S. Pat. No. 3,615,972 (Morehouse et al.) describes thermoplastic microspheres that encapsulate a liquid blowing agent. The microspheres are prepared by suspension polymerization of droplets of a mixture of monomer(s) and a blowing agent. U.S. Pat. No. 3,472,798 (Pitchforth et al.) described the preparation of polymethylmethacrylate prepared by suspension polymerization. U.S. Pat. No. 3,740,359 (Garner) and U.S. Pat. No. 4,075,138 (Garner) describes vinylidine chloride copolymer microspheres prepared from an oil phase of the monomers and a liquid blowing agent, dispersing the oil phase in an aqueous phase containing a dispersion stabilizer, polymerizing the monomers, then heating to volatilize the blowing agent. U.S. Pat. No. 3,945,956 (Garner) described expandable styrene-acrylonitrile microspheres prepared by polymerizing a mixture of styrene and acrylonitrile with a volatile liquid blowing agent.
[0046] The microsphere component may comprise a composite comprising a plurality of hollow glass, ceramic or plastic microspheres bonded together with a polymeric binder. The binder may be continuous (as in a particle or pellet), or discontinuous (as in an agglomerate) or an intermediate structure. As such, the amount of microspheres in the composite can vary widely; from about 20 to 75, preferably 20 to 60 weight % to form a pellet composite and 40 to 95, preferably 40 to 90 weight % to form an agglomerate. The microsphere composites may be of any suitable size or shape are typically at least 200 micrometers in size, and preferably 4000 micrometers or less to facilitate subsequent separation from the drilling fluid. The composites may be any desired shape including random or regular shapes.
[0047] Thermoplastic polymers may be used as a binder in the composite microsphere. Thermoplastic polymers which may be used in the present invention include but are not limited to melt-processible polyolefins and copolymers and blends thereof, styrene copolymers and terpolymers (such as Kraton™), ionomers (such as Surlyn™), ethyl vinyl acetate (such as Elvax™), polyvinylbutyrate, polyvinyl chloride, metallocene polyolefins (such as Affinity™ and Engage™), poly(alpha olefins) (such as Vestoplast™ and Rexflex™), ethylene-propylene-diene terpolymers, fluorocarbon elastomers (such as THV™ from 3M Dyneon), other fluorine-containing polymers, polyester polymers and copolymers (such as Hytrel™), polyamide polymers and copolymers, polyurethanes (such as Estane™ and Morthane™), polycarbonates, polyketones, and polyureas. The thermoplastic polymers include blends of homo- and copolymers, as well as blends of two or more homo- or copolymers. As used herein “melt-processible” refers to thermoplastic polymers having a melt index of from 3 to 30 g/10 min.
[0048] Useful polyamide polymers include, but are not limited to, synthetic linear polyamides, e.g., nylon-6 and nylon-66, nylon-11, or nylon-12. It should be noted that the selection of a particular polyamide material might be based upon the physical requirements of the particular application for the resulting reinforced composite article. For example, nylon-6 and nylon-66 offer higher heat resistant properties than nylon-11 or nylon-12, whereas nylon-11 and nylon-12 offer better chemical resistant properties. In addition to those polyamide materials, other nylon materials such as nylon-612, nylon-69, nylon-4, nylon-42, nylon-46, nylon-7, and nylon-8 may also be used. Ring containing polyamides, e.g., nylon-6T and nylon-61 may also be used. Polyether containing polyamides, such as PEBAX polyamides (Atochem North America, Philadelphia, Pa.), may also be used.
[0049] Polyurethane polymers which can be used include aliphatic, cycloaliphatic, aromatic, and polycyclic polyurethanes. These polyurethanes are typically produced by reaction of a polyfunctional isocyanate with a polyol according to well-known reaction mechanisms. Commercially available urethane polymers useful in the present invention include: PN-04 or 3429 from Morton International, Inc., Seabrook, N.H., and X4107 from B.F.Goodrich Company, Cleveland, Ohio.
[0050] Also useful are polyacrylates and polymethacrylates which include, for example, polymers of acrylic acid, methyl acrylate, ethyl acrylate, acrylamide, methylacrylic acid, methyl methacrylate, n-butyl acrylate, and ethyl acrylate, to name a few.
[0051] Other useful substantially extrudable hydrocarbon polymers include polyesters, polycarbonates, polyketones, and polyureas. These materials are generally commercially available, for example: SELAR® polyester (DuPont, Wilmington, Del.); LEXAN® polycarbonate (General Electric, Pittsfield, Mass.); KADELL® polyketone (Amoco, Chicago, Ill.); and SPECTRIM® polyurea (Dow Chemical, Midland, Mich.).
[0052] Useful fluorine-containing polymers include crystalline or partially crystalline polymers such as copolymers of tetrafluoroethylene with one or more other monomers such as perfluoro(methyl vinyl)ether, hexafluoropropylene, perfluoro(propyl vinyl)ether; copolymers of tetrafluoroethylene with ethylenically unsaturated hydrocarbon monomers such as ethylene, or propylene.
[0053] Still other fluorine-containing polymers useful in the invention include those based on vinylidene fluoride such as polyvinylidene fluoride; copolymers of vinylidene fluoride with one or more other monomers such as hexafluoropropylene, tetrafluoroethylene, ethylene, propylene, etc. Still other useful fluorine-containing extrudable polymers will be known to those skilled in the art as a result of this disclosure.
[0054] Representative examples of polyolefins useful in this invention are polyethylene, polypropylene, polybutylene, poly(1-butene), poly(3-methylbutene), poly(4-methylpentene) and copolymers of ethylene with propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene and 1-octadecene, and blends thereof. Useful commercially available polyolefins include MOPLEN and ADFLEX KS359 polypropylene available from Basell, Bloomington, Del., SRC 7644 polypropylene available from ExxonAMobil, Edison, N.J.
[0055] Representative blends of polyolefins useful in this invention are blends containing polyethylene and polypropylene, low-density polyethylene and high-density polyethylene, and polyethylene and olefin copolymers containing the copolymerizable monomers, some of which are described above, e.g., ethylene and acrylic acid copolymers; ethyl and methyl acrylate copolymers; ethylene and ethyl acrylate copolymers; ethylene and vinyl acetate copolymers-, ethylene, acrylic acid, and ethyl acrylate copolymers, and ethylene, acrylic acid, and vinyl acetate copolymers.
[0056] The useful thermoplastic polyolefins may also comprise functionalized polyolefins, i.e., polyolefins that have additional chemical functionality, obtained through either copolymerization of olefin monomer with a functional monomer or graft copolymerization subsequent to olefin polymerization. Typically, such functionalized groups include O, N, S, P, or halogen heteroatoms. Such reactive functionalized groups include carboxylic acid, hydroxyl, amide, nitrile, carboxylic acid anhydride, or halogen groups. Many functionalized polyolefins are available commercially. For example, copolymerized materials include ethylene-vinyl acetate copolymers, such as the Elvax series, commercially available from DuPont Chemicals, Wilmington, Del., the Elvamide series of ethylene-polyamide copolymers, also available from DuPont, and Abcite 1060WH, a polyethylene-based copolymer comprising approximately 10% by weight of carboxylic acid functional groups, commercially available from Union Carbide Corp., Danbury, Conn. Examples of graft-copolymerized functionalized polyolefins include maleic anhydride-grafted polypropylene, such as the Epolene series commercially available from Eastman Chemical Co., Kingsport, Tenn. and Questron, commercially available from Himont U.S.A., Inc., Wilmington, Del.
[0057] Thermoplastic microsphere composites can be prepared using any conventional technique for preparing particle-filled thermoplastic articles. The thermoplastic polymer can be heated above its melting point and the microspheres can then be mixed in. The resulting mixture may then be extruded or formed into continuous strands and the strands are cooled to solidify the moldable polymer for pelletizing on suitable equipment as is known in the art. Alternatively, a molten mixture of thermoplastic polymer and microsphere may be discharged using a pelletizing spray apparatus as is known in the art.
[0058] In a preferred method of making a microsphere composite, the microspheres, preferably glass microspheres are metered into a molten stream of thermoplastic polymer under low shear conditions to form a mixture, and the mixture is then formed into the desired size and shape. This process may comprise a two-stage extrusion process whereby a thermoplastic polymer is melted in the first stage of an extruder and conveyed to a second stage, where the microspheres are added to the molten stream. The microspheres and the thermoplastic resin are mixed in the second stage, the mixture degassed and extruded in the desired form.
[0059] Thermoset polymers may be used as the binder for the composite microsphere. As used herein, thermoset refers to a polymer that solidifies or sets irreversibly when cured. Curable binder precursor can be cured by radiation energy or thermal energy. Thermosettable compositions may include components that have a radiation or heat crosslinkable functionality such that the composition is curable upon exposure to radiant curing energy in order to cure and solidify, i.e. polymerize and/or crosslink, the composition. Representative examples of radiant curing energy include electromagnetic energy (e.g., infrared energy, microwave energy, visible light, ultraviolet light, and the like), accelerated particles (e.g., electron beam energy), and/or energy from electrical discharges (e.g., coronas, plasmas, glow discharge, or silent discharge).
[0060] Radiation crosslinkable functionality refers to functional groups directly or indirectly pendant from a monomer, oligomer, or polymer backbone that participate in crosslinking and/or polymerization reactions upon exposure to a suitable source of radiant curing energy. Such functionality generally includes not only groups that crosslink via a cationic mechanism upon radiation exposure but also groups that crosslink via a free radical mechanism. Representative examples of radiation crosslinkable groups suitable in the practice of the present invention include epoxy groups, (meth)acrylate groups, olefinic carbon-carbon double bonds, allylether groups, styrene groups, (meth)acrylamide groups, combinations of these, and the like.
[0061] Typically, radiation curable binder precursor material comprises at least one of epoxy resin, acrylated urethane resin, acrylated epoxy resin, ethylenically unsaturated resin, aminoplast resin having at least one pendant unsaturated carbonyl group, isocyanurate derivatives having at least one pendant acrylate group, isocyanate derivatives having at least one pendant acrylate group, or combinations thereof. Other suitable thermoset polymers include those derived from phenolic resins, vinyl ester resins, vinyl ether resins, urethane resins, cashew nut shell resins, napthalinic phenolic resins, epoxy modified phenolic resins, silicone (hydrosilane and hydrolyzable silane) resins, polyimide resins, urea formaldehyde resins, methylene dianiline resins, methyl pyrrolidinone resins, acrylate and methacrylate resins, isocyanate resins, unsaturated polyester resins, and mixtures thereof.
[0062] A polymer precursor or precursors may be provided to form the desired thermoset polymer. The polymer precursor or thermoset resin may comprise monomers, or may comprise a partially polymerized, low molecular weight polymer, such as an oligomer, if desired. Solvent or curative agent, such as a catalyst, may also be provided where required. In one method, the microsphere composite may be prepared by mixing the microspheres with a polymer precursor or resin and subsequently curing the polymer precursor or resin. A solvent, if any, may be removed by evaporation. The evaporation and polymerization may take place until the polymerization is substantially complete.
[0063] Epoxy (epoxide) monomers and prepolymers are commonly used in making thermoset epoxy materials, and are well known in the art. Thermosettable epoxy compounds can be cured or polymerized by cationic polymerization. The epoxy-containing monomer can also contain other epoxy compounds or blends of epoxy containing monomers with thermoplastic materials. The epoxy-containing monomer may be blended with specific materials to enhance the end use or application of the cured, or partially cured, composition.
[0064] Useful epoxy-containing materials include epoxy resins having at least one oxirane ring polymerizable by a ring opening reaction. Such materials, broadly called epoxides, include both monomeric and polymeric epoxides, and can be aliphatic, cycloaliphatic, or aromatic. These materials generally have, on the average, at least two epoxy groups per molecule, and preferably have more than two epoxy groups per molecule. The average number of epoxy groups per molecule is defined herein as the number of epoxy groups in the epoxy-containing material divided by the total number of epoxy molecules present. Polymeric epoxides include linear polymers having terminal epoxy groups (e.g., a diglycidyl ether of a polyoxyalkylene glycol), polymers having skeletal oxirane units (e.g., polybutadiene polyepoxide), and polymers having pendent epoxy groups (e.g., a glycidyl methacrylate polymer or copolymer). The molecular weight of the epoxy-containing material may vary from 58 to about 100,000 or more. Mixtures of various epoxy-containing materials can also be used.
[0065] Examples of some epoxy resins useful in this invention include 2,2-bis[4-(2,3-epoxypropyloxy)phenyl]propane (diglycidyl ether of bisphenol A) and materials under the trade designation “EPON 828”, “EPON 1004” and “EPON 1001F”, commercially available from Shell Chemical Co., Houston, Tex., “DER-331”, “DER-332” and “DER-334”, commercially available from Dow Chemical Co., Freeport, Tex., Other suitable epoxy resins include glycidyl ethers of phenol formaldehyde novolac (e.g., “DEN-431” and “DEN-428”, commercially available from Dow Chemical Co.) and BLOX 220 thermoplastic epoxy resin available from Dow, Midland, Mich. The epoxy resins used in the invention can polymerize via a cationic mechanism with the addition of appropriate photoinitiator(s). These resins are further described in U.S. Pat. Nos. 4,318,766 and 4,751,138, which are incorporated by reference.
[0066] Exemplary acrylated urethane resin includes a diacrylate ester of a hydroxy terminated isocyanate extended polyester or polyether. Examples of commercially available acrylated urethane resin include “UVITHANE 782” and “UVITHANE 783,” both available from Morton Thiokol Chemical, Moss Point, Mass., and “CMD 6600”, “CMD 8400”, and “CMD 8805”, all available from Radcure Specialties, Pampa, Tex.
[0067] Exemplary acrylated epoxy resin includes a diacrylate ester of epoxy resin, such as the diacrylate ester of an epoxy resin such as bisphenol. Examples of commercially available acrylated epoxy resin include “CMD 3500”, “CMD 3600”, and “CMD 3700”, available from Radcure Specialties.
[0068] Exemplary ethylenically unsaturated resin includes both monomeric and polymeric compounds that contain atoms of carbon, hydrogen and oxygen, and optionally, nitrogen or the halogens. Oxygen atoms, nitrogen atoms, or both, are generally present in ether, ester, urethane, amide, and urea groups. Ethylenically unsaturated resin typically has a molecular weight of less than about 4,000 and is in one embodiment an ester resulting from the reaction of compounds containing aliphatic monohydroxy groups or aliphatic polyhydroxy groups and unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, and the like.
[0069] Representative examples of other useful acrylates include methyl methacrylate, ethyl methacrylate, ethylene glycol diacrylate, ethylene glycol methacrylate, hexanediol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, glycerol triacrylate, pentaerythritol triacrylate, pentaerythritol methacrylate, and pentaerythritol tetraacrylate. Other useful ethylenically unsaturated resins include monoallyl, polyallyl, and polymethylallyl esters and amides of carboxylic acids, such as diallyl phthalate, diallyl adipate, and N,N-diallyladipamide. Still, other useful ethylenically unsaturated resins include styrene, divinyl benzene, and vinyl toluene. Other useful nitrogen-containing, ethylenically unsaturated resins include tris(2-acryloyl-oxyethyl)isocyanurate, 1,3,5-tri(2-methyacryloxyethyl)-s-triazine, acrylamide, methylacrylamide, N-methylacrylamide, N,N-dimethylacrylamide, N-vinylpyrrolidone, and N-vinylpiperidone.
[0070] Some useful aminoplast resins can be monomeric or oligomeric. Typically, the aminoplast resins have at least one pendant α,β-unsaturated carbonyl group per molecule. These α,β-unsaturated carbonyl groups can be acrylate, methacrylate, or acrylamide groups. Examples of such resins include N-hydroxymethyl-acrylamide, N,N′-oxydimethylenebisacrylamide, ortho and para acrylamidomethylated phenol, acrylamidomethylated phenolic novolac, and combinations thereof. These materials are further described in U.S. Pat. Nos. 4,903,440 and 5,236,472, which are incorporated by reference.
[0071] Useful isocyanurate derivatives having at least one pendant acrylate group and isocyanate derivatives having at least one pendant acrylate group are further described in U.S. Pat. No. 4,652,274, which is incorporated by reference. One such isocyanurate material is a triacrylate of tris(2-hydroxyethyl)isocyanurate.
[0072] Examples of vinyl ethers suitable for this invention include vinyl ether functionalized urethane oligomers, commercially available from Allied Signal, Morristown, N.J., under the trade designations “VE 4010”, “VE 4015”, “VE 2010”, “VE 2020”, and “VE 4020”.
[0073] Phenolic resins are low cost, heat resistant, and have excellent physical properties. Acid cure resole phenolic resins are disclosed in U.S. Pat. No. 4,587,291. Phenol resins used in some embodiments of the invention can have a content of monomeric phenols of less than 5%. The resins can also be modified additionally with up to 30% of urea, melamine, or furfuryl alcohol, according to known methods.
[0074] Phenol resoles are alkaline condensed, reaction products of phenols and aldehydes, wherein either mono- or polynuclear phenols may be used. In further detail, mononuclear phenols, and both mono- and polyfunctional phenols, such as phenol itself, and the alkyl substituted homologs, such as o-, m-, p-cresol or xylenols, are suitable. Also suitable are halogen-substituted phenols, such as chloro- or bromophenol and polyfunctional phenols, such as resorcinol or pyrocatechol. The term “polynuclear phenols” refers, for example, to naphthols, i.e., compounds with fused rings. Polynuclear phenols may also be linked by aliphatic bridges or by heteroatoms, such as oxygen. Polyfunctional, polynuclear phenols may also provide suitable thermosetting phenyl resoles.
[0075] The aldehyde component used to form the phenol resoles can be formaldehyde, acetaldehyde, propionaldehyde, or butyraldehyde, or products that release aldehyde under condensation conditions, such as, for example, formaldehyde bisulfite, urotropin, trihydroxymethylene, paraformaldehyde, or paraldehyde. The stoichiometric quantities of phenol and aldehyde components can be in the ratio of 1:1.1 to 1:3.0. The resins can be used in the form of aqueous solutions with a content of non-volatile substances of 60 to 85%.
[0076] Oxetane ring monomers may also be used to form the matrix phase thermoset polymers. Oxetane (oxacyclobutane) rings behave somewhat like epoxy (oxirane) rings in that catalysts and/or co-curatives, sometimes referred to as crosslinking agents, can be used to open the ring and link two or more chains together to form a crosslinked polymer. For example, polycarboxylic acid anhydrides and other polyfunctional compounds such as polyamines, polycarboxylic acids, polymercaptans, polyacid halides, or the like are capable of linking two or more oxetane sites just as epoxy sites are linked by epoxide cocuratives. The result is an increased amount of three-dimensional structure in the crosslinked or cured polymer, and hence an increased amount of rigidity of the polymer structure.
[0077] The mixture of microspheres and curable binder precursor material may be cured by an initiator selected from the group consisting of photoinitiator, thermal initiator, and combinations thereof. As used herein, a thermal initiator may be used when thermal energy is used in the at least partially curing step, and photoinitiators may be used when ultraviolet and/or visible light is used in the at least partially curing step. The requirement of an initiator may depend on the type of the curable binder precursor used and/or the type of energy used in the at least partially curing step (e.g., electron beam or ultraviolet light). For example, phenolic-based curable binder precursors typically do not require the addition of an initiator when at least thermally cured. However, acrylate-based curable binder precursors typically do require the addition of an initiator when at least thermally cured. As another example, initiators typically are not required when electron beam energy is used during the at least partially curing step. However, if ultraviolet or visible light is utilized, a photoinitiator is typically included in the composition.
[0078] Upon being exposed to thermal energy, a thermal initiator generates a free radical source. The free radical source then initiates the polymerization of the curable binder precursor. Exemplary thermal initiators include organic peroxides (e.g. benzoil peroxide), azo compounds, quinones, nitroso compounds, acyl halides, hydrazones, mercapto compounds, pyrylium compounds, imidazoles, chlorotriazines, benzoin, benzoin alkyl ethers, diketones, phenones, and mixtures thereof. Azo compounds suitable as thermal initiators in the present invention may be obtained under the trade designations “VAZO 52,” “VAZO 64,” and “VAZO 67” from E.I. duPont deNemours and Co., Wilmington, Del.
[0079] Upon being exposed to ultraviolet or visible light, the photoinitiator generates a free radical source or a cationic source. This free radical or cationic source then initiates the polymerization of the curable binder precursor.
[0080] Exemplary photoinitiators that generate a free radical source when exposed to ultraviolet light include, but are not limited to, those selected from the group consisting of organic peroxides (e.g., benzoyl peroxide), azo compounds, quinones, benzophenones, nitroso compounds, acyl halides, hydrozones, mercapto compounds, pyrylium compounds, triacrylimidazoles, bisimidazoles, chloroalkytriazines, benzoin ethers, benzil ketals, thioxanthones, and acetophenone derivatives, and mixtures thereof. Examples of photoinitiators that generate a free radical source when exposed to visible radiation are further described, for example, in U.S. Pat. No. 4,735,632 (Oxman et al.), the disclosure of which is incorporated herein by reference.
[0081] Cationic photoinitiators generate an acid source to initiate the polymerization of an epoxy resin or a urethane. Exemplary cationic photoinitiators include a salt having an onium cation and a halogen-containing complex anion of a metal or metalloid. Other useful cationic photoinitiators include a salt having an organometallic complex cation and a halogen-containing complex anion of a metal or metalloid. These photoinitiators are further described in U.S. Pat. No. 4,751,138 (Tumey et al.), the disclosure of which is incorporated herein by reference. Another example is an organometallic salt and an onium salt described in U.S. Pat. No. 4,985,340 (Palazotto et al.); the disclosure of which is incorporated herein by reference. Still other cationic photoinitiators include an ionic salt of an organometallic complex in which the metal is selected from the elements of Periodic Groups IVB, VB, VIB, VIIB, and VIIIB. These photoinitiators are further described in U.S. Pat. No. 5,089,536 (Palazotto), the disclosure of which is incorporated herein by reference.
[0082] Ultraviolet-activated photoinitiators suitable for the present invention may be obtained under the trade designations “IRGACURE 651”, “IRGACURE 184”, “IRGACURE 369” and “IRGACURE 819” from Ciba Geigy Company, Winterville, Mass., “Lucirin TPO-L”, from BASF Corp., Livingston, N.J., and “DAROCUR 1173” from Merck & Co., Rahway, N.J. In one embodiment, the total amount of initiator (either photoinitiator, thermal initiator, or combinations thereof) may be in the range from 0.1 to 10 percent by weight of the curable binder precursor; in another embodiment, from about 1 to about 5 percent by weight of the curable binder precursor. If both photoinitiator and thermal initiator are used, the ratio of photoinitiator to thermal initiator is between about 3.5:1 to about 1:1.
[0083] When using a thermoset resin, the microsphere composite may be prepared by forming precursor particles comprising the thermoset resin binder and microspheres and curing the particles. In a preferred embodiment, the first step involves forcing the binder and microspheres through a perforated substrate to form agglomerate precursor particles. Next, the agglomerate precursor particles are separated from the perforated substrate and irradiated with radiation energy to provide agglomerate particles. In a preferred embodiment, the method of forcing, separating and irradiating steps are spatially oriented in a vertical and consecutive manner, and are performed in a sequential and continuous manner. Preferably, the agglomerate particles are solidified and handleable after the irradiation step and before being collected. Reference may be made to U.S. Pat. No. 6,620,214 and incorporated herein by reference.
[0084] Methods of forcing the binder precursor and solid particulates through a perforated substrate comprise extrusion, milling, calendering or combinations thereof. In a preferred embodiment, the method of forcing is provided by a size reduction machine, manufactured by Quadro Engineering Incorporated.
[0085] In one embodiment, the agglomerate precursor particles are irradiated by being passing through a first curing zone that contains a radiation source. Preferred sources of radiation comprise electron beam, ultraviolet light, visible light, laser light or combinations thereof. In another embodiment, the agglomerate particles are passed through a second curing zone to be further cured. Preferred energy sources in the second curing zone comprise thermal, electron beam, ultraviolet light, visible light, laser light, microwave or combinations thereof.
[0086] The composite particles are generally non-spherical. In some embodiments of the invention the composite particles will have a sphericity of less than about 0.7, generally less than about 0.6, and preferably less than about 0.5, as measured according to American Petroleum Institute Method RP56, Section 5.
[0087] In a preferred embodiment, the composite particles are filamentary shaped and have a length ranging from about 100 to about 5000 micrometers and sphericity less than 0.7 (prior to sizing). Most preferably, the filamentary shaped composite particles range in length from about 200 to about 1000 micrometers. In one embodiment, the agglomerate particles may then be reduced in size after either the first irradiation step or after being passed through the second curing zone. The preferred method of size reducing is with a size reduction machine manufactured by Quadro Engineering Incorporated. In one embodiment, the cross-sectional shapes of the agglomerate particles comprise circles, polygons or combinations thereof. Preferably, the cross-sectional shape is constant. Further details regarding the process may be found in U.S. Pat. No. 6,620,214, incorporated herein by reference.
[0088] Agglomerates that contain a discontinuous binder can be made according to the following procedure. The microspheres and the binder resin are introduced into a mixing vessel. The resulting mixture is stirred until it is homogeneous. It is preferred that there be sufficient liquid in the mixture that the resulting mixture is neither excessively stiff nor excessively runny. Most resins contain sufficient liquid to permit adequate mixing. After the mixing step is complete, the mixture is caused to solidify, preferably by means of heat or radiation energy. Solidification results from either the removal of liquid from the mixture or the polymerization of the resinous adhesive. After the mixture is solidified, it is crushed to form agglomerates, which are then graded to the desired size. Devices suitable for this step include conventional jaw crushers and roll crushers.
[0089] If the binder of the agglomerate is a thermoplastic, it is preferred that the agglomerate be made according to the following procedure. The thermoplastic is heated to just above its melting temperature. Then the heated thermoplastic and the microspheres are introduced into a heated screw type extruder, and mixed until it is homogeneous. Next, the mixture is run through the die of the extruder, and the resulting extrudate is cooled and crushed to form agglomerates, which are then graded to the desired size.
[0090] The crushing and grading procedures described above frequently provide agglomerates of an undesirable size. The improperly sized agglomerates can either be recycled, e.g., by being added to a new dispersion, or discarded.
[0091] The present invention provides a drilling fluid composition comprising a drilling fluid, which may be oil- or water-based, and a composite microsphere component. The microsphere component comprises a composite of microspheres in a polymeric resin. The microsphere of the composite microsphere component may comprise any hollow microspheres of glass, ceramic or plastic that may be added to the drilling fluid (with other components of the drilling fluid known in the art) to reduce the density thereof. The composite microsphere component may be of any suitable size and shape. The polymeric resin may comprise a continuous phase having the microspheres dispersed therein, or the composite microsphere component may comprise an agglomerate of microspheres bound together by a discontinuous phase of polymeric resin. The polymeric resin may be a thermoplastic or thermoset resin.
[0092] The composite microsphere component is added to the drilling fluid composition in amounts sufficient to reduce the density of the drilling fluid at least 15%, preferably at least 20% and most preferably at least about 30%. Normally the drilling fluid has a density in the range of about 15 lbs/gal (˜8.7 kg/L). One useful drilling fluid comprises a microsphere component in an amount sufficient to reduce the density of the drilling to approximately that of seawater, or about 8 to 12 lbs/gal (˜5.2 to 7 kg/L). The amount of microsphere component added to a drilling fluid will depend on the density of the microsphere component, the initial density of the drilling fluid (without a microsphere component) and the desired final density of the drilling fluid. For example, reducing the density of a 16 lbs/gallon drilling fluid to a 10 lbs/gallon would require the addition of about 45 volume percent (or about 18 weight percent) of a microsphere component having a density of about 0.4 g/cm 3 .
[0093] The present invention also provides a method of drilling comprising the step of circulating a drilling fluid down a drill string and up an annulus between the drill string and bore hole, and introducing a microsphere component to said drilling fluid in an amount sufficient to reduce the density thereof. The drilling fluid is delivered at a sufficient volumetric rate and pressure of effect said circulation down said drill string, out a drill bit and up the annular space
[0094] The microsphere component may be added to the drilling fluid at the surface and circulated down the drill string and up the annulus of the well bore. Preferably, the microsphere component is pumped in a fluid vehicle, such as water, and pressure injected into the annulus between the drill string and the well bore to reduce the density of the drilling fluid that has been pumped from the surface down the drill string. In such a case, the microsphere component does not come into contact with the high shear environment of the drill bit. If desired, the microsphere component may be injected at multiple points along the annulus from the seabed to the surface.
[0095] In the method of the present invention, the pressure of the drilling fluid may be controlled to prevent blowouts, kicks or other uncontrolled pressure conditions. Under most well drilling applications in permeable formations, the drilling fluid pressure should be kept between pore pressure of the well and the fracturing pressure of the surround well formation. If the fluid pressure is too low, the formation fluid can force the fluid from the well-bore or annulus resulting in a kick or blowout. If the fluid pressure is too high the formation adjacent the well bore may fracture resulting in loss of fluid circulation and loss of fluid and cuttings to the fracture.
[0096] If desired, the method may further include a separation step whereby the microsphere component is separated from the recovered fluid. Such a separation step may include a preceding or subsequent step where the drill cuttings are separated to the recovered fluid. Such a microsphere component separation step may include a screening step, where the microsphere component is screened from both larger and smaller components of the recovered fluid. For example, the returning drilling fluid may first be screened to remove cuttings and subsequently screened to remove the microsphere component. With such a screening step, it is preferably that the size of the microsphere component be micrometers or more. Alternatively the separation step may comprise a flotation step where the microsphere component is recovered by floating to the surface of the recovered fluid due to the low density. As yet another alternative, the microsphere component may be separated from the recovered fluid by a centrifugal or cyclonic means whereby the returning drilling fluid is fed to a hydrocyclone and rapidly spun so that heavier density materials, such as cuttings are separated from light components, such as the microsphere, by centrifugal and centripetal forces.
[0097] The following examples are provided to illustrates some embodiments of the invention and are not intended to limit the scope of the claims. All percentages are by weight unless otherwise noted.
EXAMPLES
[0000] Glossary
[0098] A-174 Silane; 3-(trimethoxysilyl)propyl methacrylate, available from Dow Corning; Midland Mich.
[0099] Adflex™ KS-359; polyproplylene available from Basell, Wilmington, Del.
[0100] BlOx™ 220; high adhesion thermoplastic epoxy resin, Dow Chemical Co., Midland, Mich.
[0101] Cumene hydroperoxide; C 6 H 5 C(CH 3 ) 2 OOH; available from Sigma-Aldirch, Milwaukee, Wis.
[0102] Irgacure™ 651; Methylbenzoylbenzoate, available from Ciba Specialty Chemicals, Tarrytown, N.Y.
[0103] Lexan 123™; polycarbonate available from General Electric, Pittsfield, Mass.
[0104] Moplen™; Polypropylene available from Basell, Wilmington, Del.
[0105] SRC 7644™; Polypropylene available from Exxon/Mobil, Edison, N.J.
[0106] SR 351™; Trimethylolpropane triacrylate, available from Sartomer, Exton, Pa.
[0107] RD 710™; Phenolic resin, available from 3M Company, St. Paul, Minn.
[0000] Test Methods
[0000] Glass Microsphere Strength Test
[0108] An APP strength tester (available from Advanced Pressure Products, Ithaca, N.Y.) was used to determine the collapse strength of the microsphere component. The sample to be tested was suspended in glycerol and placed in a balloon. The balloon was then inserted into the strength tester and pressure is applied until the specified percentage of microspheres are ruptured (ASTM D3102-78 with 10% collapse and percent of total volume instead of void volume).
[0000] Glass Microsphere Size Measurement Test
[0109] The size distribution of each batch of glass microspheres was determined using Model 7991-01 Particle Size Analyzer (Leeds and Northrup, Pittsburgh, Pa.).
[0000] Glass Microsphere Density Determination Test
[0110] A fully automated gas displacement AccuPyc 1330 Pycnometer (available from Micromeritic, Norcross, Ga.) was used to determine the density of the glass microspheres according to ASTM D-2840-69.
[0000] Preparation of Glass Microspheres
[0111] The process that was followed for making glass microspheres is essentially described in U.S. Pat. No. 4,391,646 (Howell; Example 1) and the composition of the glass used is described in U.S. Pat. No. 4,767,726 (Marshall; Example 8). Glass microspheres used to make composites typically had a 90% size range of 10 μm-60 μm with a density of 0.4 g/cm 3 .
[0000] Preparation of Extruded Microsphere Composite
[0112] Various thermoplastic materials were co-extruded with glass microspheres using a 33 mm co-rotating twin screw extruder (Sterling Extruder Corporation, Plainfield, N.J.) with a length to diameter ratio of 24:1, multiple feed ports fitted with an underwater pelletizer (Gala Industries, Eagle Rock, Va.). Two volumetric feeders (Accurate Dry Materials Feeder, Whitewater, Wis.) were used to feed additives into the extruder with a screw speed of 250 rpm resulting in a die output rate of 5.7 pounds/hr (˜2.6 kg/hr). The material was fed in a polymer/glass microspheres weight ratio of 12.7/7.3. The compounding temperature range from hopper to die is cited in Table 1 below. Pelletized material is dried at room temperature for several days before packaging.
TABLE 1 Strength Strength Strength Temp (psi @ (psi @ (@ 19,900 Exam- range Density 10% 20% psi; ple Polymer (° C.) (g/cm 3 ) loss) loss) % loss) 1 Blox ™ 50-200 0.958 +20,000 +20,000 5.7 220 2 Moplen ™ 50-220 0.677 6,500 9,500 32.7 3 SRC 50-220 0.686 4,750 6.050 41.9 7644 ™ 4 Adflex ™ 50-220 0.669 1,400 4,800 38.8 KS-359 5 Lexan 50-260 0.912 17,600 +20,000 16 123 ™
The strength values in Table 1 show that composites of all polymers exhibited suitable strength for drilling applications.
Examples 6-10
Absorbency of Composites to Drilling Fluids
[0113] For Examples 6-10 composite microspheres (1.0 g) were placed in drilling fluids (10.0 g; available from Halliburton Energy Services) as identified in Table 2. The sample was allowed to set at room temperature for four days. The mixtures were then filtered through a 250 mesh screen, and the solid composite microsphere material was allowed to drain for 1 hour. The composite microsphere sample was then weighed (w f ) and % wt gain was calculated using the formula:
% Wt Gain = w f - 1.0 1.0 × 100
[0114] Results are listed in Table 2.
TABLE 2 % weight gain of microsphere composites in various drilling fluids. % Wt % Wt % Wt Gain Gain Gain % Wt Gain Petrofree Petrofree LVT Example Polymer Petrofree LV SF 200 6 Blox ™ 220 6.3 3.0 4.8 3.4 7 Moplen ™ 13.6 15.7 17.8 13.9 8 SRC 7644 17.7 18.5 22.9 28.6 9 Adflex ™ KS- 55.1 57.5 65.2 93.0 359 10 Lexan ™ 2.0 4.3 1.7 1.0
Examples 11-13
Preparation of Composite Microspheres with Acrylate Polymers
[0000] The composites were prepared as described in U.S. Pat. No. 6,620,214.
[0000] Procedure #1: General Procedure for Making a Composite Microsphere Precursor Slurry
[0115] A slurry was prepared by thoroughly mixing glass microspheres, acrylate resin, and initiators, using a mixer (obtained from Hobart Corporation, Troy, Ohio; model number A120T). Specific formulation can be found in Table 3. The abrasive slurry was mixed in the mixer on low speed using a flat-beater style impeller for 30 minutes and heated to a temperature within the range from about 90° F. (32° C.) to about 120° F. (49° C.) due to mechanical heating and heat of reaction. At this point, the abrasive slurry was very thick with cement-like handling characteristics. The mixed slurry was then placed in a refrigerator for at least 45 minutes to cool before further processing. The temperature of the refrigerator was in the range from about 40° F. (4° C.) to about 45° F. (7° C.).
[0000] Procedure #2: General Procedure for Making Composite Microsphere Precursor Particles
[0116] The composite microsphere precursor slurry was formed into aggregate precursor particles with the aid of the “QUADRO COMIL” material forming apparatus (obtained from Quadro Incorporated, Milbourne, N.J. under the trade designation “QUADRO COMIL”; model number 197). Depending on the desired cross sectional shape of the composite microsphere precursor particles, different shaped orifices were used. Conical 10 screens with circular shaped hole orifices were used to produce composite microsphere precursor particles with circular shaped cross sections.
[0117] The slurry was added to the hopper of the “QUADRO COMIL” by hand while the impeller was spinning at a preset speed (rpm) of 350. The rotating impeller forced the slurry through the orifices in the conical screen and when a critical length (typically, a critical length is reached when the weight of the particle is greater than any adhesive force between the formed composition and the perforated substrate) was reached, the filamentary shaped composite microsphere precursor particles separated from the outside of the screen, and fell by gravity through a UV curing chamber (obtained from Fusion UV Systems, Gaithersburg, Md.; model #DRE 410 Q) equipped with two 600 watt “d” Fusion lamps set at “high” power. The composite microsphere precursor particles were at least partially cured by exposure to the UV radiation and thereby converted into handleable and collectable particles.
[0118] In some of the examples below the composite microsphere precursor particles were further at least partially cured by placing the particles in aluminum pans and at least partially thermally curing them in a forced-air oven (obtained from Lindberg/Blue M Company, Watertown, Wis.; model number POM-246F) for about 5 hours to about 8 hours and at about 340° F. (171° C.) to about 360° F. (182° C.). Optionally, the at least partially cured composite microsphere precursor particles were reduced in size by passing them through the “QUADRO COMIL”. Typically, particles are reduced in size by passing them through the “QUADRO COMIL,” with the “QUADRO COMIL” equipped with conical screens that have relatively larger orifices than those used for forming composite microsphere precursor particles (see examples for specific details). For particle size reduction, the impeller rotation speed of the “QUADRO COMIL” was set at 252 rpm. Results of Density and Strength testing are listed in Table 4.
Example 14
Preparation of Composite Microspheres with Phenolic Resins
[0119] Example 14 was prepared essentially following the procedures described above in Preparation of Composite Microspheres with Acrylate Polymers with the exception that the slurry composition in Procedure #1 is replaced with the composition cited in Table 5 and the microsphere precursor particles in Procedure #2 are subjected to temperatures at about 260° F. (127° C.) to about 280° F. (138° C.) for 10-30 minutes instead of temperatures at at about 340° F. (171° C.) to about 360° F. (182° C.) for 5-8 hours to effect thermal cure. Results of Density and Strength testing are listed in Table 6.
TABLE 3 Composition of Acrylate Composite Microsphere Slurries Material Example 11 (g) Example 12 (g) Example 13 (g) SR351 tm 225 225 275 Cumene 2.5 2.5 2.5 hydroperoxide Glass microspheres 500 450 400 A-174 45 45 45 Irgacure 651 2.5 2.5 2.5
[0120]
TABLE 4
Densities and Strengths of Acrylate Composite Microspheres.
Strength (psi @ 10%
Strength (psi @
Example
Density (g/cm 3 )
loss)
20% loss)
11
0.5359
5200
6400
12
0.5315
4550
5600
13
0.6109
8650
11,300
[0121]
TABLE 5
Composition of Phenolic Composite Microsphere Slurry
Material
Example 14 (g)
Glass microspheres
425.0
710 phenolic resin
225.0
DI water
30.0
[0122]
TABLE 6
Densities and Strengths of Phenolic Composite Microspheres.
Strength (psi @
Strength (psi @
Example
Density (g/cm 3 )
10% loss)
20% loss)
14
0.5332
5800
10,850 | The present invention provides a drilling fluid composition and a method of drilling comprising a drilling fluid, which may be oil- or water-based, and a composite microsphere component. The invention drilling fluid composition advantageously reduces the density of a conventional fluid, reduces costs associated with pumping and overcomes problems associated with conventional gas-injection processes. The invention uses conventional drilling and pumping equipment, requires no sea-floor based pumps and may be easily pressure-controlled to maintain the pressure of the fluid. | 2 |
[0001] This application claims the benefit of U.S. Provisional application 60/645,713 filed Jan. 21, 2005.
BACKGROUND OF THE INVENTION
[0002] The present invention is a method for operating a rapid pressure swing adsorption unit. In particular, the method operates the rapid pressure swing adsorption unit so that the tail gas (exhaust gas) is released at a pressure greater than 30 psig.
[0003] Pressure swing adsorption (PSA) is widely practiced commercially to separate and purify gases, including air separation. Rapid pressure swing adsorption (RCPSA), which operates on shorter cycle times than PSA, can also be used for air separation. The tail gas (adsorbed gas) is emitted from each process at a blowdown pressure, typically 5-15 psig.
[0004] In the oil refinery setting, it is often desirable to separate a feed gas into a tail gas (adsorbed gas) and a non-adsorbed gas and send the tail gas to a fuel header or other refinery waste stream that is typically at pressures of 60-80 psig. Therefore, it is desirable that the tail gas be emitted at these higher pressures. Otherwise, a tail gas compressor must be inserted between the separation unit and the fuel header. Purity and/or recovery of the product gas must also be high.
SUMMARY OF THE INVENTION
[0005] The present invention is a method for operating a rapid cycle pressure swing adsorption (RCPSA) system having a total cycle time, t TOT , to separate a feed gas into product gas and tail (exhaust) gas. The method includes the steps of passing the feed gas having a purity F %, where F is the percentage of the feed gas which is the non-adsorbable component, into a sorbent bed which selectively adsorbs the tail gas and passes the product gas out of the bed, for time, t F , wherein the product gas has a purity of non-adsorbable component P % and a rate of recovery of R %. Recovery R % is the ratio of amount of non-adsorbable component in the product to the amount of adsorbed component in the feed. Then the bed is co-currently depressurized for a time, t CO , followed by counter-currently depressurizing the bed for a time, t CN wherein desorbate (tail gas or exhaust gas) is released from the bed at a pressure greater than or equal to 30 psig The bed is purged for a time, t P , typically with a portion of the product gas. Subsequently the bed is repressurized for a time, t RP , typically with a portion of product gas or feed gas, wherein the cycle time, t TOT , is equal to the sum of the individual cycle times comprising the total cycle time, i.e.
t TOT =t F +t CO +t CN +t P +t RP
The present invention is carried out such that 3 specific ratios are adhered to defined as
0 <t CO /t F ≦⅓, and
t CN /t F ≦¼, and
⅕ ≦t CO /t P , and
with conditions resulting such that either (1) the rate of recovery, R %≧80% for a product purity to feed purity ratio, P %/F %≧1.1, and/or (2) the rate of recovery, R %≧90% for a product purity to feed purity ratio, 0<P %/F %<1.1
[0006] The tail gas is released at a pressure high enough so that the tail gas may be fed to another device absent tail gas compression.
[0007] In a more preferred embodiment, the tail gas pressure is greater than or equal to 60 psig. In a most preferred embodiment, the tail gas pressure is greater than or equal to 80 psig. The product gas includes hydrogen, methane, an olefin, oxygen, nitrogen, helium, or a saturate. The tail gas may be fed into another unit in a refinery or petrochemical unit such as a hydroprocessing unit, a reforming unit, a fluidized catalytic cracker unit or a methane synthesis unit.
[0008] In another preferred embodiment, the only step in depressuring the bed is co-current flow. That is, the counter-current depressurizing step is omitted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a schematic diagram of the apparatus for a typical rapid pressure swing adsorption (RCPSA) process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] Pressure Swing Adsorption (PSA) is a method that is widely practiced commercially to separate and purify gases. The method consists of five steps performed as a cycle. FIG. 1 shows a schematic drawing of the system to carry out the method. The first step is a feed step wherein mixtures of feed gases at high pressure are passed through valve 4 over adsorbent materials 12 with valve 6 closed and valve 18 open. The material 12 selectively removes components of the mixture, thereby producing a product gas enriched in a preferred component, which passes out valve 18 . The second step is a co-current depressurization in which valve 4 is closed and the pressure reduces in adsorbent material 12 . Step 3 is a countercurrent depressurizing step in which valve 4 is closed, valve 6 is opened. In this step, the adsorbent material is cleaned by the depressurizing to a lower pressure followed by step 4 of purging at this lower pressure in reverse direction to feed flow. The effluent produced during these steps ( 3 and 4 ) is called the tail gas. After these four steps, the adsorbent material is pressurized in step 5 with either the feed or product gas to prepare it for the next feed step. For continuous production, the cycles are practiced using several vessels that undergo different steps of the rudimentary cycle described. In the present invention these five steps are operated in such a manner that the tail gas pressure is high enough to send it to another unit without need of a tail gas compressor.
[0011] Rapid pressure swing adsorption (RCPSA) is distinguished from conventional pressure swing adsorption (CPSA) by the shorter cycles times it employs. For example, RCPSA cycle times are typically less than a minute while CPSA cycle times are typically greater than 2-4 minutes. Hardware (valving, piping, configuration of vessels) to perform these cycles also differs considerably and vendors of equipment for both CPSA and RCPSA exist. While CPSA is currently practiced in refineries for recovery of gases such as hydrogen, RCPSA is currently commercially widespread only for air separation. The following examples illustrate the subject matter of the present invention. A computer simulation model of the PSA process is used to determine process performance at different condition.
EXAMPLE 1
[0012] In one embodiment of the improved integrations of PSA with a refinery claimed here, an RCPSA to produce an olefin product was compared to CPSA. For example, a computer simulation shows that for the separation of a 65 vol % ethylene—35% ethane stream, 0.16 MMSCFD (million standard cubic feet per day), on 4 A zeolite, RCPSA with 20 sec feed step is able to produce ethylene at greater than 90% purity with ⅙th (one-sixth) the adsorbent quantity needed by a CPSA with a one minute feed step. This particular example is only illustrative of the application of RCPSA to other olefin-paraffin separations.
EXAMPLE 2
[0013] In this example, the refinery stream is at 480 psig with tail gas at 65 psig whereby the pressure swing is 6.18. The feed composition and pressures are typical of refinery processing units such as those found in hydroprocessing or hydrotreating applications. In this example typical hydrocarbons are described by their carbon number i.e. C1=methane, C2=ethane etc. The RCPSA is capable of producing hydrogen at >99% purity and >81% recovery over a range of flow rates. Tables 1a,b shows the results of computer simulation of the RCPSA and the input and output percentages of the different components for this example. Table 1a,b also show how the hydrogen purity decreases as recovery is increased from 89.7% to 91.7% for a 6 MMSCFD stream at 480 psig and tail gas at 65 psig.
TABLE 1a, b Composition (mol %) of input and output from RCPSA (67 ft 3 ) in H2 purification. Feed is at 480 psig, 122 deg F. and Tail gas at 65 psig. Feed rate is about 6 MMSCFD. feed product Tail-Gas Case 1a. Higher purity Step Times in seconds are t F = 1, t CO = 0.167, t CN = 0, t P = 0.333, t RP = 0.5 H2 at 98.6% purity, 89.7% recovery H2 88.0 98.69 45.8. C1 6.3 1.28 {overscore (2)}5.1 C2 0.2 0.01 1.0 C3 2.6 0.01 12.3 C4+ 2.9 0.00 14.8 H2O 2000 vppm 65 vppm 9965 vppm total (MMSCFD) 6.162 4.934 1.228 480 psig 470 psig 65 psig Case 1b. Higher purity Step Times in seconds are t F = 1, t CO = 0.333, t CN = 0, t P = 0.167, t RP = 0.5 H2 at 97.8% purity, 91.7% recovery H2 88.0 97.80 45.9 C1 6.3 2.14 25.0 C2 0.2 0.02 1.0 C3 2.6 0.02 12.3 C4+ 2.9 0.00 14.9 H2O 2000 vppm 131 vppm 10016 vpm total (MMSCFD) 6.160 5.085 1.074 480 psig 470 psig 65 psig
[0014] The RCPSA's described in the present invention operate a cycle consisting of different steps. Step 1 is feed during which product is produced, step 2 is co-current depressurization, step 3 is counter-current depressurization, step 4 is purge, usually counter-current) and step 5 is repressurization with product. In the RCPSA's described here at any instant half the total number of beds are on the feed step. Further the time duration of the steps 2 through 5 is equal to the time duration for the entire step 1 . Typical step times for the total cycle can be 0.5 s-2 s and even lower. Steps 2 - 5 are fractions of this time.
TABLE 2 Effect of step durations on H2 purity and recovery from an RCPSA (67 ft 3 ). Same conditions as Table 1. Feed is at 480 psig, 122 deg F. and Tail gas at 65 psig. Feed rate is about 6 MMSCFD. purity recovery t F t CO t CN t P t RP % % s s s s s 2a. Without counter-current depress 98.2 84.3 1 0.283 0.05 0.167 0.5 98.3 85 1 0.166 0.167 0.167 0.5 99.9 80 1 0.083 0.25 0.167 0.5 2b. With counter-current depress, Intermediate pressure = 105 psig 97.8 91.7 1 0.333 0 0.167 0.5 98.7 90 1 0.166 0 0.334 0.5 99 88 1 0.083 0 0.417 0.5
Conditions for Table 2 are the same as in Table 1. Table 2a shows that when there is no counter-current depressurization step, the co-current depress duration should be less than ⅓ rd of feed step time to maintain high purity >99%.
[0015] Similarly Table 2b shows that with counter-current depressurization, the total depressurization time should be preferably less than ⅓ rd of feed step time and the counter-current depress time should be less ¼ th of the feed step time to maintain high recovery (>80%).
EXAMPLE 3
[0016] This example shows a 10 MMSCFD refinery stream, once again containing typical components, as shown in feed column of Table 3. The stream is at 480 psig with RCPSA tail gas at 65 psig whereby the absolute pressure swing is 6.18. For e.g. the feed composition contains 74% H2. Once again the RCPSA of the present invention is capable of producing hydrogen at >99% purity and >85% recovery from these feed compositions. Tables 3a,b shows the results of this example.
TABLE 3a, b Composition (mol %) of input and output from RCPSA (53 ft 3 ) in H2 purification. Feed is at 480 psig, 101 deg F. and Tail gas at 65 psig. Feed rate is about 10 MMSCFD. feed product Tail-Gas Case 3a. Higher purity Step Times in seconds are t F = 0.583, t CO = 0.083, t CN = 0, t P = 0.25, t RP = 0.25 H2 at 99.98% purity and 86% recovery H2 74.0 99.98 29.8 C1 14.3 0.02 37.6 C2 5.2 0.00 13.8 C3 2.6 0.00 7.4 C4+ 3.9 0.00 11.0 H2O 2000 vppm 0.3 vppm 5387 vppm total (MMSCFD) 10.220 6.514 3.705 480 psig 470 psig 65 psig Case 3b. Lower purity Step Times in seconds are t F = 0.5, t CO = 0.167, t CN = 0, t P = 0.083, t RP = 0.25 H2 at 93% purity and 89% recovery H2 74.0 93.12 29.3 C1 14.3 6.34 31.0 C2 5.2 0.50 16.6 C3 2.6 0.02 8.9 C4+ 3.9 0.00 13.4 H2O 2000 vppm 142 vppm 6501 vpm total (MMSCFD) 10.220 7.240 2.977 480 psig 470 psig 65 psig
In both cases 3a, 3b, although tail gas pressure is high at 65 psig, the present invention shows that high purity (99%) is obtained only when the duration of the co-current depressurization step ( 5/60 s) is less than ⅓ of the feed step duration ( 35/60 s).
[0017] Tables 2 and 3a show that for both 6 MMSCFD and 10 MMSCFD flow rate conditions, very high purity hydrogen at ˜99% and >85% recovery is achievable with the RCPSA. In both cases the tail gas is at 65 psig. Such high purities and recoveries of product gas achieved using the RCPSA with all the exhaust produced at high pressure have not been discovered before and are a key feature of the present invention.
[0018] Table 3c shows the results for an RCPSA (volume=49 cubic ft) that delivers high purity (>99%) H2 at high recovery for the same refinery stream discussed in Tables 3a,b. Table 3c. Part a. shows that that high purity H2 is produced when the duration of the co-current depressurization step is less than ⅓ rd of the feed step time, for the case where there is no counter-current depressurization step.
TABLE 3c Effect of step durations on H2 purity and recovery from an RCPSA (49 ft 3 ). Feed is at 480 psig, 101 deg F. and Tail gas at 65 psig. Feed rate is about 10 MMSCFD. Without counter-current depress purity recovery t F t CO t CN t P t RP % % s s s s s 95.6 87.1 0.5 0.167 0 0.083 0.25 97.6 86 0.5 0.117 0 0.133 0.25 99.7 85.9 0.5 0.083 0 0.167 0.25
EXAMPLE 4
[0019] In this example, Table 4 further illustrates the performance of RCPSA's operated in accordance with the invention being described here. In this example, the feed is a typical refinery stream and is at a pressure of 300 psig. The RCPSA of the present invention is able to produce 99% pure hydrogen product at 83.6% recovery when all the tail gas is exhausted at 40 psig. In this case the tail gas can be sent to a flash drum or other separator or other downstream refinery equipment without further compression requirement. In absolute terms the pressure swing in this example is 5.52. Simultaneously the RCPSA also removes CO to <2 vppm, which is extremely desirable for refinery units that use the product hydrogen enriched stream. Lower levels of CO ensure that the catalysts in the downstream units operate without deterioration in activity over extended lengths. Conventional PSA cannot meet this CO specification and simultaneously also meet the condition of exhausting all the tail gas at the higher pressure, such as at typical fuel header pressure or the high pressure of other equipment that processes such RCPSA exhaust. Since all the tail gas is available at 40 psig or greater, no additional compression is required for integrating the RCPSA with refinery equipment. Prior art typically uses compression/expansion via a rotating shaft.
TABLE 4 Composition (mol %) of input and output from RCPSA (4 ft 3 ) in carbon monoxide and hydrocarbon removal from hydrogen. Feed is at 300 psig, 101 deg F., and Feed rate is about 0.97 MMSCFD. Step Times in seconds are t F = 0.5, t CO = 0.1, t CN = 0, t P = 0.033, t RP = 0.066 H2 at 99.99% purity and 88% recovery feed product Tail-Gas H2 89.2 99.98 48.8 C1 3.3 0.01 13.9 C2 2.8 0.01 13.9 C3 2.0 0.00 10.2 C4+ 2.6 0.00 13.2 CO 50 1.1 198.4 total 0.971 0.760 0.211 300 psig 290 psig 40 psig
EXAMPLE 5
[0020] Table 5a,b compares the performance of RCPSA's operated in accordance with the invention being described here. The stream being purified has lower H2 in the feed (51% mol) and is a typical refinery/petrochemical stream. In both cases, 5a, b, a counter current depressurization step is applied after the co-current step. In accordance with the invention, Table 5a shows that high H2 recovery (81%) is possible even when all the tail gas is released at 65 psig or greater. In contrast, the RCPSA where some tail-gas is available as low as 5 psig, loses hydrogen in the counter-current depressurization such that H2 recovery drops to 56%. In addition, the higher pressure of the stream in Table 5a indicates that no tail gas compression is required.
TABLE 5a, b Effect of Tail Gas Pressure on recovery Example of RCPSA applied to a Feed with H2 concentration (51.3 mol %) Composition (mol %) of input and output from RCPSA (31 ft 3 ) in H2 purification. Feed is at 273 psig, 122 deg F. and Feed rate is about 5.1 MMSCFD. feed product Tail-Gas 5a. Step Times in seconds are t F = 0.5, t CO = 0.083, t CN = 0.033, t P = 0.25, t RP = 0.133 [a] Tail gas available from 65-83 psig, H2 at 99.7% purity and 81% recovery H2 51.3 99.71 20.1 C1 38.0 0.29 61.0 C2 4.8 0.00 8.0 C3 2.2 0.00 3.8 C4+ 3.7 0.00 6.4 H2O 4000 vppm 0.7 vppm 6643 vppm total (MMSCFD) 5.142 2.141 3.001 273 psig 263 psig 65-83 psig 5b. Step Times in sec. are t F = 0.667, t CO = 0.167, t CN = 0.083, t P = 0.083, t RP = 0.33 [b] Tail gas available from 5-65 psig, H2 at 99.9% purity and 56% recovery H2 51.3 99.99 34.2 C1 38.0 0.01 48.8 C2 4.8 0.00 6.9 C3 2.2 0.00 3.4 C4+ 3.7 0.00 6.2 H2O 4000 vppm 0.0 vppm 5630 vppm total (MMSCFD) 5.142 1.490 3.651 273 psig 263 psig 5-65 psig
EXAMPLE 6
[0021] In this example, Table 6a,b compares the performance of RCPSA's operated in accordance with the invention being described here. In these cases, the feed pressure is 800 psig and tail gas is exhausted at either 65 psig or at 100 psig. The composition reflects typical impurities such H2S, which can be present in such refinery applications. As can be seen, high recovery (>80%) is observed in both cases with the high purity >99%. In both these cases, only a cocurrent depressurization is used and the effluent during this step is sent to other beds in the cycle. Tail gas only issues during the countercurrent purge step. Table 6c shows the case for an RCPSA operated where some of the tail gas is also exhausted in a countercurrent depressurization step following a co-current depressurization. The effluent of the co-current depressurization is of sufficient purity and pressure to be able to return it one of the other beds in the RCPSA vessel configuration that is part of this invention. Tail gas i.e., exhaust gas, issues during the counter-current depressurization and the counter-current purge steps.
[0022] In all cases the entire amount of tail gas is available at elevated pressure which allows for integration with other high pressure refinery process. This removes the need for any form of rotating shaft machinery or compressor while producing high purity gas at high recoveries. In accordance with the broad claims of this invention, these cases are only to be considered as illustrative examples and not limiting either to the refinery, petrochemical or processing location or even to the nature of the particular molecules being separated.
TABLE 6a, b, c Example of RCPSA applied to a high pressure feed Composition (mol %) of input and output from RCPSA (18 ft 3 ) in H2 purification. Feed is at 800 psig, 122 deg F. and Feed rate is about 10.1 MMSCFD. feed product Tail-Gas 6a. Step Times in seconds are t F = 0.91, t CO = 0.25, t CN = 0, t P = 0.33, t RP = 0.33 [a] Tail gas at 65 psig, H2 at 99.9% purity and 87% recovery H2 74.0 99.99 29.5 C1 14.3 0.01 37.6 C2 5.2 0.00 14.0 C3 2.6 0.00 7.4 C4+ 3.9 0.00 10.9 H2S 20 vppm 0 55 vppm total (MMSCFD) 10.187 6.524 3.663 800 psig 790 psig 65 psig 6b. Step Times in seconds are t F = 0.91, t CO = 0.25, t CN = 0, t P = 0.33, t RP = 0.33 [b] Tail gas at 100 psig, H2 at 99.93% purity and 80.3% recovery H2 74.0 99.93 38.1 C1 14.3 0.07 32.8 C2 5.2 0.00 12.5 C3 2.6 0.00 6.5 C4+ 3.9 0.00 9.6 H2S 20 vppm 0 vppm 49 vppm total (MMSCFD) 10.187 6.062 4.125 800 psig 790 psig 100 psig 6c. Step times in seconds are t F = 0.91, t CO = 0.083, t CN = 0.25, t P = 0.167, t RP = 0.41 [c] Tail gas from 65-100 psig, H2 at 99.8% purity and 84% recovery H2 74.0 99.95 28.9 C1 14.3 0.05 39.0 C2 5.2 0.00 13.7 C3 2.6 0.00 7.2 C4+ 3.9 0.00 10.6 H2S 20 vppm 0.01 vppm 53 vppm total (MMSCFD) 10.187 6.373 3.814 800 psig 790 psig 65-100 psig
EXAMPLE 7
[0023] Table 7 compares the performance of RCPSA's operated in accordance with the invention being described here. The stream being purified has higher H 2 in the feed (85% mol) and is a typical refinery/petrochemical stream. In these examples the purity increase in product is below 10% (i.e. P/F<1.1). Under this constraint, the method of the present invention is able to produce hydrogen at >90% recovery without tail gas compression.
TABLE 7a, b, c Example of RCPSA applied to a Feed with H2 concentration (85 mol %). Composition (mol %) of input and output from RCPSA (6.1 ft 3 ). Feed is at 480 psig, 135 deg F. and Feed rate is about 6 MMSCFD. feed product Tail-Gas 7a. Step Times in seconds are t F = 0.5, t CO = 0.33, t CN = 0.167, t P = 0.167, t RP = 1.83 recovery = 85% H2 85.0 92.40 57.9 C1 8.0 4.56 17.9 C2 4.0 1.79 13.1 C3 3.0 1.16 10.4 C4+ 0.0 0.00 0.0 H2O 2000 866.5 6915 total (MMSCFD) 6.100 4.780 1.320 480 psig 470 psig 65 psig 7b. Step Times in sec. are t F = 1, t CO = 0.333, t CN = 0.167, t P = 0.083, t RP = 0.417 recovery = 90% H2 85.0 90.90 58.2 C1 8.0 5.47 18.1 C2 4.0 2.23 12.9 C3 3.0 1.29 10.1 C4+ 0.0 0.00 0.0 H2O 2000 1070.5 6823 total (MMSCFD) 6.120 5.150 0.969 480 psig 470 psig 65 psig 7c. Step Times in sec. are t F = 2, t CO = 0.667, t CN = 0.333, t P = 0.167, t RP = 0.833 recovery = 90% H2 85.0 90.19 55.2 C1 8.0 6.21 18.8 C2 4.0 2.32 13.9 C3 3.0 1.17 11.3 C4+ 0.0 0.00 0.0 H2O 2000 1103.5 7447 total (MMSCFD) 6.138 5.208 0.93 480 psig 470 psig 65 psig
[0024]
F
P
t CO /t F
t CN /t F
t CO /t P
Feed
Product
P/F
R
cocurrent/
countercurrent/
(cocurrent/
Tail gas P
Purity
Purity
PURITY
recovery
feed
feed
purge)
case #
EXAMPLE #
psig
%
%
RATIO
%
ratio
ratio
ratio
Table 8a Purity ratio (P/F) ≧ 1.1
1
3
65
74
99.9
1.35
74
1
1
prior art
1.000
2
3
65
74
99
1.34
73
0.5
0.5
not according to invention
1.000
3
3
65
74
84
1.14
74
0.5
0.25
not according to invention
0.500
4
3
65
74
85
1.15
76
0.45
0.1
not according to invention
0.450
5
3
65
74
99
1.34
70
0.333
0.333
not according to invention
0.500
6
3
65
74
99
1.34
68
0.1
0.1
not according to invention
0.150
7
2
65
88
99.9
1.14
80
0.083
0.25
preferred
0.498
8
3
65
74
99
1.34
81
0.1
0.1
preferred
0.300
9
5
65
51
99
1.94
81
0.167
0.067
preferred
0.279
10
2
65
88
98.3
1.12
85
0.167
0.167
preferred
1.002
11
2
65
88
98.2
1.12
84.3
0.28
0.05
preferred
1.680
12
2
65
88
97.8
1.11
91.7
0.333
0
preferred
1.998
13
3
65
74
93
1.26
89
0.333
0
preferred
1.998
14
3
65
74
95.6
1.29
87.1
0.333
0
preferred
1.998
15
3
65
74
97.6
1.32
86
0.23
0
preferred
0.8625
16
6
100
74
99
1.34
80
0.27
0
preferred
0.743
17
3
65
74
99
1.34
84
0.27
0
preferred
0.743
18
3
65
74
99.7
1.35
85.9
0.167
0
preferred
0.501
19
2
65
88
98.6
1.12
89.7
0.167
0
preferred
0.501
20
3
65
74
99.9
1.35
86
0.14
0
preferred
0.328
21
2
65
88
99
1.13
88
0.08
0
preterred
0.200
Table 8b Purity ratio (P/F) < 1.1
1
7
65
85
92.6
1.09
85
0.833
0.333
not according to invention
5.000
2
7
65
85
92.4
1.09
85
0.667
0.333
not according to invention
2.000
3
3
65
74
79
1.07
85
0.625
0.2
not according to invention
1.000
4
7
65
85
90
1.06
90
0.333
0.167
preferred by invention
4.000
5
7
65
85
91
1.07
90
0.333
0.167
preterred by invention
4.000
[0025] Prior art exists where some portion of the PSA exhaust gas is removed at an intermediate, elevated pressure. However, in every instance, the PSA is operated such that some exhaust is produced at low (5 psig=20 psia) pressure. Such low pressure exhaust can also contribute to lower recovery since this exhausted gas which, contains larger and larger fractions of the heavy, undesirable components also contains valuable light product, such as hydrogen. This is a consequence of the deeper levels of cleaning offered by the larger pressure swing. However it is not fully understood in the art that it is this additional enrichment of heavies that can also lead to lower recovery due to the unavoidable loss of the light component along with vented heavy impurity. This heavy impurity must be vented since it cannot be returned to the RCPSA system and re-used, for example as pressurization gas to pressurize another vessel in the RCPSA undergoing a pressurization step. FIG. 2 shows a comparison of the tail gas pressure of the present invention with the prior art.
[0026] Another feature disclosed here is that an RCPSA can operated at high purity and recovery of light product while using only co-current depressurization/blowdown steps, i.e. without resorting to a counter-current blow down step. Such a counter-current blowdown steps is cited in the prior art as a means to generate energy recovery by using a portion of the counter-current exhaust to drive a separate item of machinery called a turboexpander. Such turboexpanders then can simultaneously drive a compressor operating on the same shaft. In this manner the prior art claims to reduce the compression requirements. As is evident no such device is required in the present invention since all the exhaust gas is available at the elevated pressure thereby eliminating any rotational compressor device such as rotating shaft. In addition, by controlling the duration of the co-current blowdown step such that co-current blowdown gas issuing from the product end (i.e. co-current to feed step) does not drop in purity below a specified amount, typically the feed composition, then all the co-current blow-down gas can be used to pressurize other beds in the RCPSA cycle. This features greatly conserves light product and increases recovery of light product. | The present invention is a method for operating a rapid cycling pressure swing adsorption (RCPSA) having a cycle time, T, to separate a feed gas into a non-adsorbed gas and tail gas. The method includes the steps of passing the feed gas having a purity of F % at high pressure into a first end of a bed which selectively adsorbs the tail gas and passes the product gas out a second end of the bed for a time, F. The product gas has a purity, P %, and a rate of recovery of R %. Then the bed is cocurrently drpressurized for a time, t CO , followed by countercurrently depressurizing the bed for a time, t CN . The bed is then purged for a time, t P , wherein desorbate (tail gas) is released at the first end of the bed at a pressure greater than 30 psig, Subsequently the bed is repressurized for a duration, t RP .
R >80%, P/F≧1.1 or R≧90%, 0<P/F<1.1. | 1 |
TECHNICAL FIELD
The present invention relates to telecommunications through mobile wireless transmission systems and particularly to the use of such systems to continuously monitor and correct operating conditions in the automobile by transmissions from remote locations.
BACKGROUND OF RELATED ART
With the globalization of business, industry and trade wherein transactions and activities within these fields have been changing from localized organizations to diverse transactions over the face of the world, the telecommunication industries have, accordingly, been expanding rapidly. Wireless telephones, such as cellular telephones, have become so pervasive that their world wide number is in the order of hundreds of millions. While the embodiment to be subsequently described uses cellular telephones as the example, the principles of the invention would be applicable to any wireless transmission device.
Despite the rapid expansion of and the proliferation of wireless telephones and particularly cellular telephones and networks, the industry is experiencing a decrease in consumer demand for wireless cellular telecommunications products. As a result, the industry is seeking new and expanded uses for its products. The present invention offers such an expanded application for wireless cellular telephone technology in the continuous monitoring and correction of automobile operating systems. The term automobile is meant to include any type of motor vehicle using public highways, e.g. trucks and cycles.
Over the last generation, the use of microprocessors and central processors in automobiles has been rapidly expanding. In addition to a central computer, referred to as the engine control unit, automobiles have upwards of fifty microprocessors dispersed throughout the automobile to control the sensing and controlling of many discrete operations. The increase in such microprocessors has been necessitated by the imposition of emission and fuel economy standards and safety standards, reduction in wiring, as well as advanced comfort and convenience features.
With all of this on-board data processing during automobile operations, increasing self-diagnostics have been built into the automobile wherein defects or faults are often self-adjusted within the automobile without any apparent effect on operations. Of course, with such complex operations, it may at times be the case that the on-board diagnostic system cannot adjust or correct the fault. Also, the fault may be mechanical, physical or electrical and require some form of manual repair. Accordingly, the automobile has a central storage module in which sensed data relative to faults and defects, particularly faults and defects that cannot be self-adjusted, is stored. Then, the automobile must visit a diagnostic and repair shop where the defects and stored data relative thereto are interpreted and the defect repaired. Alternatively, as described in U.S. Pat. No. 6,181,994, when a problem arises, the automobile may establish a wireless communication with a diagnostic center so that the particular problem may be analyzed and repaired.
SUMMARY OF THE PRESENT INVENTION
The present invention provides an advance over the above-discussed prior art that involves continuously monitoring automobile operations, performance and operating conditions from the remote diagnostic centers through continuous wireless transmissions so that faults may be immediately recognized and either corrected or the operator warned or actions remotely initiated to limit or prevent damage or safety hazards within the automobile operations.
Accordingly, the present invention provides a system for continuously monitoring and correcting operational conditions in an automobile that comprises a plurality of sensing devices in said automobile; each device for respectively continuously sensing an operational parameter of said automobile; a wireless transmitter in said automobile for transmitting said continuously sensed parameters to a diagnostic station remote from said automobile; apparatus in said diagnostic station for analyzing the sensed data in order to determine defective operational conditions in said automobile; and apparatus associated with said diagnostic station for wireless transmission of data relative to said determined defective operating conditions back to said automobile. The data transmitted back to said automobile may include data for selectively activating the apparatus already on-board the automobile for correcting the defective operational conditions. Whenever practical, apparatus for correcting said defective conditions corrects said conditions transparently to the operator of said automobile.
Where the automobile conventionally includes the plurality of embedded microprocessors for controlling automobile operations, the corrected defective operating conditions may be in these embedded microprocessors. The automobile may also include an output device for informing the automobile operator of the defective operating conditions, particularly dangerous operating conditions. Also, under such dangerous or potentially harmful conditions, there may be apparatus in said automobile for limiting the operation of the automobile in response to a determined defective operating condition.
As will be subsequently described in greater detail, the wireless transmission system used for the present invention may conveniently be wireless cellular telephonic systems.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawings, in conjunction with the accompanying specification, in which:
FIG. 1 is a block diagram of a generalized data processing system including a central processor unit that provides an illustration of an on-board automobile operations control system wirelessly connected to the diagnostic center in the present invention;
FIG. 2 is a generalized diagrammatic view of a portion of a wireless mobile cellular telecommunications network including a base station connected to a Public Switched Transmission Network (PSTN) showing the continuous transmission paths to and from automobile and diagnostic center in accordance with the invention;
FIG. 3 is an illustrative flowchart describing the setting up of the elements needed for the program of the invention for continuously remotely monitoring and controlling automobile operations over a cellular telecommunications network; and
FIG. 4 is a flowchart of an illustrative simplified run of the program set up in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , there is provided a diagrammatic view of a typical computer control system that may function as an automobile on-board computer control for sensing various parameters and controlling the automotive operations and functions, including the previously described monitoring and control functions, as well as the apparatus for continuously transmitting to and from the remote diagnostic centers for analyzing and correcting operational defects and communicating and correcting such faults remotely through wireless cellular communications.
It should be understood that the actual illustrative parameters being sensed or the particular defects being corrected are not themselves specifically pertinent to the invention. However, what is pertinent is how they illustrate that defects in automobile operating conditions requiring advanced detection and correction by diagnostic and repair centers are detected and controlled on a real-time basis by continuous monitoring and transmissions between the automobile and the remote diagnostic centers via wireless communications. Embedded control units 27 are positioned in dozens of places throughout the automobile. Typically, such control units are combinations of sensors and microprocessors controlling activators to function as sensors in making minor adjustments to valves and gauges, etc., to maintain parameters within operational ranges. Control units 27 are connected via I/O adapter 11 to a central processing unit 30 that, in turn, is interconnected to various other components by system bus 32 and coordinates the operations. An operating system 35 that runs on processor 30 provides control and is used to coordinate the functions of the various components of the control system. The OS 35 is stored in Random Access Memory (RAM) 31 ; which, in a typical automobile control system, has from four to eight megabytes of memory. The programs for the various automobile monitor and control functions, including those of the present invention, are permanently stored in Read Only Memory (ROM) 33 and moved into and out of RAM to perform their respective functions. The automobile has a basic display 43 controlled through display adapter 42 to provide information to the driver, including the safety and other information from the remote diagnostic center, as will be subsequently described. The automobile operator may provide interactive commands to the automobile control system through a user input 36 that may conveniently be implemented by standard dashboard buttons connected via an appropriate input adapter 37 .
The information from control units 27 is stored in a central storage unit 28 where it will be available for advanced diagnostics. In automobiles, there are programs available by which the central processing unit will analyze this stored information and then determine whether the time is appropriate for the automobile to be brought to a diagnostic and repair center to repair defective operating conditions. The system will then give the operator appropriate warning via display 43 . In accordance with the present invention, the stored data in module 28 is wirelessly transmitted to a remote diagnostic center on a continuous or real time basis as will be subsequently described. During the operation of the automobile, this data is continuously transmitted via cellular transceiver adapter 15 to cellular transceiver 16 mounted within the automobile with antenna 17 over a wireless cellular telephone system that will be described in greater detail with respect to FIG. 2. A transceiver is basically any conventional wireless cellular (transmitting/receiving) telephone mounted in the automobile under the control of processor 30 and operating as will hereinafter be described.
In FIG. 2 , automobile 10 has unit 12 that is representative of the whole control system shown in FIG. 1 transmitting through transceiver 16 via cellular signal 14 between antenna 17 and the nearest cellular tower 22 .
At this point, some general background information on cellular telephone systems should be reviewed in order for the invention to be better understood.
In the cellular system for the handheld mobile wireless phone, an area such as a city is broken up into small area cells. Each cell is about ten square miles in area. Each has its base station that has a tower for receiving/transmitting and a base connected into PSTN. Even though a typical carrier is allotted about 800 frequency channels, the creation of the cells permit extensive frequency reuse so that tens of thousands of people in the city can be using their cell phones simultaneously. Cell phone systems are now preferably digital with each cell having over 160 available channels for assignment to users. In a large city, there may be hundreds of cells, each with its tower and base station. Because of the number of towers and users per carrier, each carrier has a Mobile Telephone Switching Office (MTSO) that controls all of the base stations in the city or region and controls all of the connections to the land based PSTN. When a client cell phone gets an incoming call, MTSO tries to locate what cell the client mobile phone is in. The MTSO then assigns a frequency pair for the call to the cell phone. The MTSO then communicates with the client over a control channel to tell the client or user what frequency channels to use. Once the user phone and its respective cell tower are connected, the call is on between the cell phone and tower via two-way long range RF communication. In the United States, cell phones are assigned frequencies in the 824-894 MHz ranges. Since transmissions between the cell telephone and cell tower are digital, but the speaker and microphone in the telephone are analog, the cell telephone has to have a D to A converter from the input to the phone speaker and an A to D converter from the microphone to the output to the cell tower.
Accordingly, with respect to FIG. 2 , cellular transceiver 16 transmits and receives signals to and from towers 22 within the 824-894 MHz frequencies. Once appropriate contact is established with tower 22 , the transmission would be conventional. The signals are passed through base station 23 to switching center 24 that then controls the routing of the call to a PSTN 25 . The above-mentioned MTSO is associated with the switching center 24 . The PSTN then, in the conventional cellular manner, routes the call through switching center 21 through wired connection to and from the remote Diagnostic Center 28 that comprises a data storage device 29 for the received data and conventional diagnostic means, i.e. a conventional diagnostic center except that it receives data transmitted wirelessly on a real-time basis and provides the corrective and informative data back to the automobile involving the path through switching centers 21 and 19 , PSTN 25 and a cellular tower 22 back through transceiver 16 .
Now, with reference to the programming shown in FIG. 3 , there will be described how the system and programs of the present invention are set up. In an automobile having a standard on-board computer system and a plurality of conventional sensors for sensing a variety of operational parameters, there is set up a module for storing the sensed parameters on a continuous basis, step 71 . Simpler on-board diagnostics are provided whereby sensed parameters are diagnosed by computer and microprocessor controls to thereby adjust simple defective automobile operating conditions within the automobile, step 72 . A cellular telephone transceiver is set up in the automobile, step 73 . A wireless connection is provided between the transceiver and a remote station that furnishes diagnostics on automobiles based upon and responsive to an input representative of the sensed parameters, step 74 . The diagnostic center provides an output relative to any defective operating condition in the automobile beyond the simple defective conditions that were adjustable in step 72 . This output is provided back to the automobile over the wireless path, step 75 . Apparatus is provided, step 76 , in the automobile to correct the defective operating conditions provided by the diagnostic center in step 75 . The correction is preferably transparent to the operator, step 76 . There is also an output provided in step 75 warning the operator of dangerous driving conditions, step 77 , that may result from the sensed data provided to the diagnostic center alone or that information in combination with other information that the diagnostic center may get from independent sources, e.g. weather conditions. For example, in the case where the sensed defect is diminished traction; that alone may not pose an immediate danger. However, if the diagnostic center also becomes aware of potential wet weather conditions, it may issue an appropriate warning. Also, if the defect results in potentially dangerous driving conditions, the diagnostic center may transmit a wireless signal that will block or otherwise limit the operation of the automobile, step 78 .
Now, with reference to the flowchart of FIG. 4 , a simplified illustrative run of the process set up in FIG. 3 will be described. A determination is made as to whether the automobile is on or being operated, step 80 . If Yes, the sensors are monitored, step 81 , and the sensed data is stored in the data storage module in the automobile, step 82 . A determination may be made as to whether a particular defect is correctable by the onboard computer/microprocessor in the automobile, step 83 . If Yes, the defect is corrected on-board, transparently to the operator if possible, step 91 , and the sensing process is returned to step 80 via branch “A” and continued. If the decision in step 83 is No, the data is stored in the storage module and continuously transmitted to the remote diagnostics center, step 84 . A determination is made as to whether there is an uncorrected defect that the diagnostic center can correct, step 85 . If No, the sensing process is returned to step 80 via branch “A” and continued. If Yes, the diagnostic center transmits appropriate correction data back to the automobile, step 86 , to preferably correct transparently, step 87 , and if appropriate, data is displayed in the automobile, step 88 . Also, the diagnostic center may determine whether there are any dangerous conditions, step 89 . If No, the sensing process is returned to step 80 via branch “A” and continued. If Yes, the diagnostic center may send a signal to limit or stop the use of the automobile, step 90 .
Although certain preferred embodiments have been shown and described, it will be understood that many changes and modifications may be made therein without departing from the scope and intent of the appended claims. | Continuously monitoring automobile operations, performance and operating conditions from the remote diagnostic centers through Continuous wireless transmissions so that faults may be immediately recognized and corrected or the operator warned or actions remotely initiated to limit or prevent damage or safety hazards. A plurality of sensing devices in said automobile; each device for respectively continuously sensing an operational parameter of the automobile; a wireless transmitter in the automobile for transmitting the continuously sensed parameters to a diagnostic station remote from automobile; apparatus in the diagnostic station for analyzing said parameters in order to determine defective operational conditions in the automobile; and apparatus associated eith said diagnostic station for wieless transmission of data relative to the determined defective operating conditions back to said automobile. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a Divisional of U.S. patent application Ser. No. 13/633,717, entitled Apparatus and Methods for Large Particle Ash Separation From Flue Gas Using Screens Having Semi-Elliptical Cylinder Surfaces, filed Oct. 2, 2012, the disclosure of which is hereby incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure is related to the control of particulate emissions from industrial plants such as coal fired plants. More specifically, the present disclosure is related to the separation of large particle ash from flue gas utilizing screens.
BACKGROUND
[0003] Coal is a primary source of energy today and is commonly used as fuel to produce electricity. A byproduct of producing electricity in a coal combustion process is nitrous oxide (NOx), which is emitted with a flue gas from coal burning electrical generating plants. This nitrous oxide is considered a pollutant to the atmosphere. Catalytic reactors are used to address this type of pollution by reducing the nitrous oxide concentration in the flue gas. Ash is another byproduct of burning coal and typically comprises silicon dioxide, calcium oxide, carbon and many other constituents depending on the makeup of the coal being burned. The combustion ash particles are usually small (up to 300 micro meters in diameter) and usually suspended in the flue gas. However, the combustion ash particles can form large particle ash (LPA), which may have a diameter exceeding 1 centimeter. LPA formation can be traced to combustion conditions in the boiler and clay like fly ash deposits on superheater tubes and backpass. The catalytic reactors are equipped with a plate or honeycomb-type catalyst and may have a pitch or opening ranging up to 8 millimeters. LPA particles are larger than the catalyst opening and therefore clogs up the catalytic reactor. As such, methods for separating ash from flue gas have been developed.
[0004] For example, U.S. Pat. No. 7,531,143, entitled “Arrangement for separating coarse ash out of a flue gas stream,” discloses screens with pleated arrangements for separating ash particles from flue gas. In practice, these screens experience blockage in certain areas of the pleated arrangement, which creates high velocity zones that cause damage to the screens. As a result, these pleated screens have to be replaced frequently or perform inefficiently and increase pressure drop in the system. It should also be noted that channels through which flue gas flows are large and, at least for this reason, screens used in these channels to separate ash from flue gas are also large and can be relatively costly.
[0005] U.S. Pat. No. 7,556,674, entitled “Method and device for the separation of dust particles,” discloses a system involving a baffle arrangement for deflecting ash particles from the flue gas towards hoppers, which collect the ash particles. This system requires a long duct to settle out the ash particles. The length of the duct makes this system relatively expensive.
[0006] The pleated screen design and baffle arrangement utilizing gravimetric forces do not economically remove large particle ash. Another problem in the art is that the ash particles in the flue gas erode structural duct members and separation screens. High flue gas velocities combined with hard ash particles will lead to significant metal wastage of this equipment. In summary, existing systems and methods for screening ash particles from flue gas are associated with high operating costs and high capital expenditure.
BRIEF SUMMARY
[0007] The current disclosure is directed to apparatus and methods for separating ash particles from a flue gas using a screen having a plurality of semi-elliptical cylinder surfaces. According to embodiments, the semi-elliptical cylinder surfaces have holes through which the flue gas flows and through which the ash particles will not pass. The semi-elliptical cylinder shape ensures a uniform velocity profile at the screen surface. Further, the semi-elliptical cylinder shaped screen arrangement allows for the strategic exposure of the internal hole walls of the screen to the incoming ash and flue gas. Depending on the concave or convex configuration of the screen having semi-elliptical cylinder surfaces, more or less wall material is exposed to the ash particles. Furthermore, the semi-elliptical cylinder shaped screen arrangement increases the surface area of the screen and reduces flue gas velocity at the screen surface and overall pressure drop over the screen. Further yet, in embodiments, the semi-elliptical screen arrangement assures that a coated-surface of the screen is maximized in the concave position of the screen thus extending the utilization life of the screen material.
[0008] Embodiments of the disclosure include methods of reducing the velocity of a flue gas passing through screening apparatus used for separating flue gas from ash particles. The methods may include replacing a first screen of the screening apparatus with a second screen comprising a plurality of semi-elliptical cylinder surfaces. The semi-elliptical cylinder surfaces have holes through which the flue gas flows and through which the ash particles will not pass.
[0009] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
[0011] FIGS. 1A and 1B show a screen having a plurality of semi-elliptical cylinder surfaces according to embodiments of the disclosure;
[0012] FIGS. 2A and 2B show a screen having a plurality of semi-elliptical cylinder surfaces according to embodiments of the disclosure;
[0013] FIGS. 3A and 3B show a screen having a plurality of semi-elliptical cylinder surfaces according to embodiments of the disclosure;
[0014] FIG. 4 shows a system for separating ash particles from flue gas according to embodiments of the disclosure;
[0015] FIG. 5A shows a prior art system for separating ash particles from flue gas;
[0016] FIG. 5B shows a prior art flat screen;
[0017] FIGS. 6A and 6B show flat screens;
[0018] FIGS. 7A to 7C show a semi-elliptical cylinder surface according to embodiments of the disclosure, and
[0019] FIGS. 8A to 8C show screens according to embodiments of the disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 5A shows prior art system 50 for separating large ash particles from flue gas. Ash particles, as discussed herein are large and may be about 1-2 centimeters in diameter. System 50 represents a typical coal fired power plant boiler arrangement. At boiler 500 , coal is mixed with air (from preheater 505 ) and burned. The burning coal causes an increase in temperature in boiler 500 such that water injected into boiler 500 is vaporized to steam. As mentioned above, the burning coal produces ash particles 105 , which flows with hot flue gas 104 through duct 501 . Duct 501 leads to screen 506 . Screen 506 has holes having a diameter such that flue gas is allowed to pass through screen 506 . However, at least some ash particles are too big to pass through the holes of screen 506 . Because these ash particles are too big to pass through the holes of screen 506 , they accumulate in hopper 502 . Flue gas passes through screen 506 and enters duct 503 . Duct 503 channels flue gas 104 to Selective Catalytic Reduction (SCR) Catalyst 504 , which removes nitrous oxide from flue gas 104 . The flue gas 104 leaving SCR Catalyst 504 may then be discharged into the atmosphere or cleaned further before discharge into the atmosphere.
[0021] Screen 506 is a pleated screen as known in the art and described for example, in U.S. Pat. No. 7,531,143. After screen 506 has been in operation for some time, ash particulate matter lodges in section 507 a of pleat 507 and blocks that section. This blockage may cause the flue gas to flow through triangular pleat 507 at a non-uniform velocity. This non-uniform velocity can cause deterioration of screen material and rupturing of the screen. When this happens, particulate matter that should be screened passes through screen 506 .
[0022] Screens that are essentially flat panels, such as flat screen 508 shown in FIG. 5B , do not have the problem described above with respect to pleated screens. However, flat panel screens, such as flat screen 508 , causes a high pressure drop in the order of 0.5 to 1 inch water column, as flue gas passes through it. This high pressure drop is consistent with the high velocity at which flue gas flows through flat screen 508 .
[0023] FIGS. 1A-3B show screens having a plurality of semi-elliptical cylinder surfaces according to embodiments of the disclosure. FIG. 1A shows screen 10 having semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 . In embodiments, screen 10 is made from a single layer of material such as metal, plastic, composites and combinations thereof. Semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 have holes 101 that allow flue gas 104 to flow through screen 10 but does not allow ash particles 105 to flow through screen 10 . That is, ash particles 105 have a cross sectional area or a diameter that is greater than the cross sectional area or diameter of holes 101 , respectively. In embodiments, holes 101 have a cross sectional area of about 1 mm 2 -200 mm 2 . Whatever the size of holes 101 , ash particles 105 are larger than holes 101 . It should be noted that, in practice, some ash particles are small enough to pass through, and do pass through, holes 101 .
[0024] The flow of flue gas/ash particles mixture 104 / 105 to semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 and the screening of ash particles 105 do not cause a buildup of ash particles, as occurs with respect to pleat 507 of screen 506 . For instance, screen 10 does not have an “apex shaped portion”—section 507 a that traps large ash particles. Furthermore, when ash particles 105 hit screen 10 , screen 10 's elliptical shape cause ash particles 105 to fall away from screen 10 under the influence of gravitational forces. In other words, screens as disclosed herein are designed to block the flow of large particle ash in a manner such that the ash particles collect in or on other equipment apart from the screens. This is unlike filters, which are designed to trap particulates within the filter itself. Referring again to FIG. 1A , ash particles 105 are collected away from screen 10 in, for example, a hopper. Because screen 10 is not designed to have a buildup of ash particles 105 on it, the velocity of flue gas across semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 (and screen 10 as a whole) is uniform.
[0025] In addition to not being susceptible to blockages, the shape of semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 reduce the velocity of flue gas 104 by increasing the surface area of the screen as compared with the surface area of flat screen 508 . The pressure drop may be calculated from the following formula:
[0000] ΔP=fv 2
where f=friction factor and v=the velocity of the flue gas
In embodiments of the disclosure, screen 10 may also include screen side sections 102 . Sections 102 may also have holes 101 for separating ash particles 105 from flue gas 104 . In embodiments, screen side sections 102 may be a solid plate without holes.
[0027] As can be seen from FIG. 1B , semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 have foci points 103 - 1 to 103 - 3 respectively. The foci points are the points representing the focal line, based on the elliptical shape, at which light rays would focus (or substantially focus) when the semi-elliptical surfaces are exposed to light if semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 are reflective. It should be noted, however, that this disclosure does not require reflective surfaces, which is mentioned here only to explain what is meant by focal point in the context of elliptical shapes. Semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 may be any type of ellipse (e.g. a circle or a parabolic ellipse). The type of ellipse will determine the exact location of foci points 103 - 1 to 103 - 3 . Notably, in the embodiment shown in FIGS. 1A and 1B , flow direction F of flue gas/ash particular mixture 104 / 105 is from the side of screen 10 on which foci points 103 - 1 to 103 - 3 lie. In other words, FIGS. 1A and 1B show a concave configuration.
[0028] Screen 20 have the features of screen 10 , except that, as shown in FIGS. 2A and 2B , screen 20 has semi-elliptical cylinder surfaces 200 - 1 to 200 - 3 with a convex configuration because foci points 203 - 1 to 203 - 3 are on the opposite side of flow F (i.e. flow of flue gas/ash particle mixture 104 / 105 ). The semi-elliptical convex shaped surfaces of screen 20 are also not prone to blockages (thereby facilitating uniform velocity distribution of flue gas 104 ) and has a higher surface area than flat screen 508 (assuming screen 508 has the same perimeter as screen 20 ). The higher surface area of screen 20 reduces flue gas velocity as compared with flat screen 508 . The perimeter of the screens illustrated herein is 2h+2w, where h is the height and w is the width of the screens as illustrated in FIGS. 1A , 2 A and 5 B. For purposes of discussion and comparison, all the screens described herein are assumed to have the same perimeter. In embodiments of the disclosure, screen 20 may also include screen side sections 202 . Sections 202 may also have holes 201 for separating ash particles 105 from flue gas 104 . In embodiments, screen side sections 202 may be a solid plate without holes. It should be noted that any number of sides 202 may have holes or may be a solid plate without holes. In embodiments, holes 201 have a cross sectional area of about 1 mm 2 -200 mm 2 .
[0029] Screen 30 , shown in FIGS. 3A and 3B , is a combination of the features of screen 10 ( FIGS. 1A to 1B ) with the features of screen 20 ( FIGS. 2A and 2B ). FIGS. 3A and 3B show screen 30 having semi-elliptical cylinder surfaces 300 - 1 to 300 - 4 . Screen 30 has both concave and convex semi-elliptical cylinder surfaces. As shown in FIG. 3B , semi-elliptical cylinder surfaces 300 - 1 to 300 - 4 have foci points 303 - 1 to 303 - 4 respectively, which are on different sides of flow F (i.e. flue gas/ash particle mixture 104 / 105 ). Semi-elliptical cylinder surfaces 300 - 1 to 300 - 4 have holes 301 that allow flue gas 104 to flow through screen 30 but does not allow ash particles 105 to flow through screen 30 . That is, ash particles 105 have a cross sectional area or a diameter that is greater than the cross sectional area or diameter of holes 301 , respectively.
[0030] Again, screens with semi-elliptical surfaces in concave and convex orientation are not prone to blockages and facilitate uniform velocity distribution of flue gas 104 . Further, the surface area of screen 30 is relatively larger than the surface area of flat screen 508 , of screen 10 and of screen 20 , which all have the same perimeter. This larger surface area of screen 30 increases flue gas velocity as compared to flat screen 508 , screen 10 and screen 20 . In embodiments of the disclosure, screen 30 may also include screen side sections 302 . Sections 302 may also have holes 301 for separating ash particles 105 from flue gas 104 . In embodiments, screen side sections 302 may be a solid plate without holes. In embodiments, holes 301 have a cross sectional area of about 1 mm 2 -200 mm 2 .
[0031] FIG. 4 shows a system for separating ash particles from flue gas according to embodiments of the disclosure. System 40 shows a coal fired power plant boiler arrangement. Boiler 400 (using air from preheater 405 ) burns coal to produce steam as described above with respect to boiler 500 . The ash produced by burning the coal flows with hot flue gas (as mixture 104 / 105 ) through duct section 401 . Duct section 401 leads to screen 10 . Screen 10 is located across the lumen of duct section 401 such that flue gas 104 has to pass through screen 10 to enter duct section 403 . In other words, screen 10 extends from wall to wall of the duct ( 401 and 403 ) such that there is screening across all of the lumen of the duct.
[0032] As described above, screen 10 has semi-elliptical cylinder surfaces 100 - 1 to 100 - 3 . Holes 101 of screen 10 have a diameter or cross sectional area such that flue gas 104 is allowed to pass through screen 10 but ash particles 105 are too big to pass through holes 101 of screen 10 . Because ash particles 105 are too big to pass through holes 101 , ash particles 105 fall away from screen 10 and accumulate in hopper 402 . At the same time, flue gas 104 passes through screen 10 into duct section 403 , which channels flue gas 104 to SCR Catalyst 404 (a destination equipment). SCR Catalyst 404 removes nitrous oxide from the flue gas. Flue gas 104 is then discharged into the atmosphere or cleaned further before discharge into the atmosphere. In embodiments, screens 20 and 30 can be used in system 40 instead of screen 10 or in addition to screen 10 . Any combination of screens 10 , 20 or 30 may be used in embodiments of the disclosure. Furthermore, screens 10 , 20 and 30 may be used in a system that includes other types of separation equipment, such as baffle arrangements, deflector plates, other types of screens and the like.
[0033] According to embodiments of the disclosure, the pressure drop in large ash particle separator systems may be reduced by using the screen designs disclosed herein. For instance, flue gas velocity may be reduced by replacing a flat screen or a pleated screen, in the separator system (such as the system shown in FIG. 5 ), with a screen that includes a plurality of semi-elliptical cylinder surfaces, such as screens 10 , 20 , 30 or combinations thereof. In embodiments, this change can produce a reduction in flue gas velocity of about up to 20 percent and a reduction of pressure drop of about 40 percent. In embodiments, this change can produce a reduction in flue gas velocity of about up to 40 percent and a reduction of pressure drop of about 60 percent. In embodiments, the screens as disclosed herein may be used to replace separation systems such as baffle based systems, deflector based systems, prior art screen systems and the like.
[0034] FIGS. 6A and 6B show flat screens 600 . Flat screen 600 includes hexagonal shaped holes 602 , formed by material M. Material M is typically a metal such as iron, aluminum, steel and the like. However, material M could also be plastic, ceramic composites and the like. When ash particles hit material M of screen 600 , they erode material M. In order for material to withstand the effect of processes (such as abrasion) brought about by ash particles hitting material M and the flow of flue gas 104 and particles (that are small enough) through holes 602 , material M may be specially formulated or coated with other substances so that it is resistant to these impacts. Specially formulating or coating material M extends the life of screen 600 . Material M has top section 603 and internal section 604 . Coating top sections 603 can be done easily using a spraying device because these sections are fully exposed. Internal section 604 , however, has to be coated by the use of a spray device at an angle. For example, spray device 605 , as shown in FIG. 6B , is positioned in a manner such that when material M is sprayed with appropriate coating, the coating contacts section 604 .
[0035] FIGS. 7A to 7C show screen 700 according to embodiments of the disclosure. Screen 700 , may also be made of material M and may have a similar hexagonal structure as screen 600 . However, in screen 700 , these hexagonal structures are in an elliptical cylindrical surface. When ash particles hit material M of screen 600 , they erode material M. To reduce this erosion, high efficiency ash removal systems must ensure uniform flow conditions as well as use high performance erosion resistant surface treatments. Like screen 600 , material M of screen 700 may be specially formulated or coated with other substances so that it is resistant to these impacts. Specially formulating or coating material M extends the life of screen 700 . The coating material may include ceramic metal composite.
[0036] FIG. 7C shows screen 700 and the views that FIGS. 7A and 7B represent. FIG. 7B is a view from the side where focal point 705 is located while FIG. 7A is a view from the opposite side. Screen 700 has holes 702 , which are similar to holes 602 shown in FIGS. 6A and 6B . In screen 700 ( FIG. 7A ), however, internal sections 704 are more exposed than internal sections 604 because the bending of screen 700 into the semi-elliptical cylinder shape pushes internal surface 704 outwards. In this way, screen 700 presents a configuration in which it is much easier to coat internal sections 704 with a selected coating material than coating sections 604 .
[0037] FIG. 7B shows screen 700 from the side of focal point 705 . That is, internal sections 704 are less exposed than internal sections 604 . Thus, if screen 700 is used in the concave configuration (i.e. flow of flue gas is from the side on which focal point 705 is located) less of internal sections 704 are exposed as compared to internal sections 604 . Thus, in addition to making it easier to coat internal surfaces, configuring screens to have semi-elliptical cylinder surfaces can decrease the surface area that will be exposed to the effects of abrasion from ash particles hitting screen 700 . Consequently, in the concave configuration shown in FIG. 7B , it might not be necessary to provide any or as much coating of internal sections 704 as compared to the internal coating needed for internal sections 604 .
[0038] Therefore, for different applications of ash separation, a determination may be made as to which of the concave or convex semi-elliptical cylinder designs is more efficient. For example, a determination may be made whether the reduction in cost due to the ease of coating internal sections 704 outweighs the increased exposure of internal section 704 if screen 700 is used in a convex configuration. In sum, screens with semi-elliptical cylinder surfaces provide flexibility in designing screen separating systems.
[0039] The screens disclosed herein offer plants (that separate ash particles from flue gas) much more versatility in designing flue gas/ash particle separation systems as compared to traditional screens (e.g. flat screens) and other separation mechanisms. For instance, by changing a flat screen of a particular perimeter to a screen with semi-elliptical cylinder surfaces and the same perimeter as the flat screen, one can change the screen surface area exposed to the flue gas/ash particle mixture.
[0040] Screens having both concave and convex semi-elliptical cylinder surfaces provide a further benefit in the art. Specifically, in order to achieve a particular surface area of screen, less depth is required for screens with both concave and convex semi-elliptical cylinder surfaces. This feature is illustrated by comparing FIGS. 8A and 8B with FIG. 8C . FIGS. 8A and 8B show concave and convex orientation screens with depth distance “d”. FIG. 8C shows a screen with both concave and convex orientation with depth “½d.” Thus, FIG. 8C provides the same surface area as FIGS. 8A and 8B with half the depth.
[0041] In sum, embodiments of the disclosure involves screens that are longer lasting and operates at a lower pressure drop, at lower velocity for the flue gas and with more uniform velocity distribution of the flue gas. Further, embodiments of the screens disclosed offers more versatility as compared to traditional screens.
[0042] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. | Apparatus for separating ash particles from a flue gas. The apparatus includes a screen that has a plurality of semi-elliptical cylinder surfaces. The semi-elliptical cylinder surfaces having holes through which said flue gas flows and through which the ash particles will not pass. The screen has a single layer for performing the separation in a manner such that the ash particles fall away from the screen and collect outside of the screen. A method of reducing velocity of a flue gas passing through screening apparatus for separating flue gas from ash particles. The method includes replacing a first screen of the screening apparatus with a second screen that has a plurality of semi-elliptical cylinder surfaces. | 8 |
This is a continuation-in-part of U.S. patent application Ser. No. 737,611 filed Jul. 30, 1991, now U.S. Pat. No. 5,178,409, which is in turn a continuation-in-part of U.S. Ser. No. 555,977 filed Jun. 19, 1990, now abandoned, which is in turn a continuation-in-part of U.S. Ser. No. 133,480 filed Dec. 22, 1987, now abandoned, which is in turn a continuation-in-part of U.S. Ser. No. 008,800 filed Jan. 30, 1987, now abandoned and U.S. Ser. No. 133,052 filed Dec. 22, 1987, now abandoned which is in turn a continuation-in-part of U.S. Ser. No. 011,471 filed Jan. 30, 1987, now abandoned.
FIELD OF THE INVENTION
This invention relates to catalyst compositions, to a method for preparing such catalyst compositions, to a method of using such catalysts and to products produced with such catalyst compositions. More particularly, this invention relates to compositions, comprising ionic metallocene catalyst compositions which are active to polymerize olefins, diolefins and/or acetylenically unsaturated monomers to homopolymer and copolymer products.
BACKGROUND OF THE INVENTION
Soluble Ziegler-Natta type catalysts for the polymerization of olefins are well known in the art. Generally, these catalysts comprise a Group IV-B metal compound and a metal alkyl cocatalyst, particularly an aluminum alkyl cocatalyst. A subgenus of such catalysts is that wherein the Group IV-B metal component comprises a bis(cyclopentadienyl) Group IV-B metal compound (i.e.--a "metallocene"), particularly a titanium compound, in combination with an aluminum alkyl cocatalyst. While speculation remains concerning the actual structure of the active catalyst species of this subgenus of soluble Ziegler-Natta type olefin polymerization catalysts, it appears generally accepted that the structure of the catalytically active species is a Group IV-B metal cation in the presence of a labile stabilizing anion. This is a theory advocated by Breslow and Newburg, and Long and Breslow, in their respective articles in J. Am. Chem. Soc., 1959, Vol. 81, pp. 81-86, and J. Am. Chem. Soc., 1960, Vol. 82, pp. 1953-1957. As there indicated, studies have suggested that the catalytically active species is a titanium-alkyl complex or a species derived therefrom when a titanium compound; viz., bis(cyclopentadienyl)titanium dihalide, and an aluminum alkyl are used as a catalyst or catalyst precursor. The presence of ions, all being in equilibrium, when a titanium compound is used was also suggested by Dyachkovskii, Vysokomol. Soyed., 1965, Vol. 7, pp. 114-115 and by Dyachkovskii, Shilova and Shilov, J. Polymer. Sci., Part C, 1967, pp. 2333-2339. That the active catalyst species is a cation complex when a titanium compound is used, was further suggested by Eisch et al., J. Am. Chem. Soc., 1985, vol. 107, pp. 7219-7221.
While the foregoing articles teach or suggest that the active catalyst species is an ion pair wherein the Group IV-B metal component is present as a cation, all of the articles teach the use of a cocatalyst comprising a Lewis acid either to form or to stabilize the active ionic catalyst species. The active catalyst is, apparently, formed through a Lewis acid-Lewis base reaction of two neutral components (the metallocene and the aluminum alkyl), leading to an equilibrium between a neutral catalytically inactive adduct and the active catalyst ion pair. As a result of this equilibrium, there is a competition for the anion which must be present to stabilize the active cation catalyst species. This equilibrium is, of course, reversible and such reversal deactivates the active catalyst species. Further, many, if not all, of the Lewis acids heretofore contemplated for use in soluble Ziegler-Natta type catalyst systems are chain transfer agents and, as a result, prevent effective control of the product polymer molecular weight and molecular weight distribution. Still further, the catalyst systems heretofore proposed do not generally facilitate incorporation of a significant amount of a plurality of different monomers or random distribution of such monomers when used in copolymerization processes, particularly α-olefin copolymerization processes.
The aforementioned metallocene catalyst systems are not highly active, nor are they generally active when the Group IV-B metal is zirconium or hafnium. More recently, however, active Ziegler-Natta type catalysts have been found which are formed when bis(cyclopentadienyl) compounds of the Group IV-B metals, including zirconium and hafnium, are combined with alumoxanes. As is well known, these systems, particularly those employing a zirconocene, offer several distinct advantages, including much higher activities than the aforementioned bis(cyclopentadienyl)titanium catalysts and the production of polymers with narrower molecular weight distributions than those from conventional Ziegler-Natta catalysts. Achiral bis(cyclopentadienyl)hafnium compounds, hafnocenes, used with alumoxane cocatalysts have offered few, if any, advantages when compared to analogous titanocenes or zirconocenes with respect to catalyst activity, polymer molecular weights, or extent or randomness of comonomer incorporation. Giannetti, Nicoletti, and Mazzochi, J. Polym. Sci., Polym. Chem., 1985, Vol. 23, pp. 2117-2133, claim that the ethylene polymerization rates of hafnocenes are five to ten times slower than those of similar zirconocenes while there is little difference between the two metallocenes in the molecular weight of the polyethylene formed from them. European Patent Application No. 200,351 A2 ( 1986) suggests that in the copolymerization of ethylene and propylene there is little difference between titanocenes, zirconocenes and hafnocenes either in polymer molecular weights and molecular weight distributions or in ability to incorporate propylene randomly. Recently, however, Ewen et al. disclosed in J. Am. Chem. Soc., 1987, Vol. 109, pp. 6544-6545, that chiral hafnocenes used with an alumoxane cocatalyst give isotactic polypropylene of higher molecular weight than that obtained from analogous chiral zirconocenes. In light of the deficiencies of the metallocene catalyst systems heretofore contemplated, a need still exists for an improved metallocene catalyst system which: (1) permits better control of polymer product's molecular weight and molecular weight distribution; (2) is not subject to activation equilibrium, and (3) does not require the use of an undesirable excess of the cocatalyst. The need for a catalyst system which will facilitate the production of higher molecular weight polymeric products and facilitate incorporation of a larger amount of comonomer into a copolymer is also believed to be readily apparent.
SUMMARY OF THE INVENTION
This invention provides improved ionic metallocene catalyst compositions which are useful in the polymerization of olefins, diolefins and/or acetylenically unsaturated monomers. This invention provides a method for preparing such improved catalyst compositions. The improved catalysts are not subject to ion equilibrium reversal deactivation and permit better control of the product polymer molecular weight and molecular weight distribution. The improved catalysts, particularly certain hafnium containing catalysts, yield relatively high molecular weight polymers, yield copolymers containing relatively large amounts of a plurality of comonomers which are also distributed in a manner at least approaching randomness, and provide polymeric products having relatively narrow molecular weight distributions.
The catalyst composition comprises a Group IV-B metal cation and a non-coordinating anion, which composition is represented by one of the general formulae:
{[(A--Cp)MX.sub.1 ].sup.+ }.sub.d [B'].sup.d- ( 1)
{[(A--Cp)MX.sub.5 L'].sup.+ }.sub.d [B'].sup.d- ( 2)
wherein:
(A--Cp) is either (Cp)(Cp') or Cp--A'--Cp'; Cp and Cp' are the same or different cyclopentadienyl rings substituted with from zero to five substituent groups S, each substituent group S being, independently, a radical group which is a hydrocarbyl, substituted-hydrocarbyl, halocarbyl, substituted-halocarbyl, hydrocarbyl-substituted organometalloid, halocarbyl-substituted organometalloid and halogen radicals or Cp and Cp' are cyclopentadienyl rings in which any two adjacent S groups are joined forming a C 4 to C 20 ring to give a saturated or unsaturated polycyclic cyclopentadienyl ligand; and A' is a bridging group restricting rotation of the Cp and Cp' rings;
M is titanium, zirconium or hafnium;
L' is a neutral Lewis base;
X 1 is a hydride radical, hydrocarbyl radical, substituted-hydrocarbyl radical, halocarbyl radical, substituted-halocarbyl radical, hydrocarbyl-substituted organometalloid radical or halocarbyl-substituted organometalloid radical;
X 5 is a hydride radical, hydrocarbyl radical or substituted-hydrocarbyl radical, hydrocarbyl-substituted organometalloid radical or halocarbyl-substituted organometalloid radical, which radical may optionally be covalently bonded to both M and L'; and
B' is a chemically stable, non-nucleophilic anionic complex having a molecular diameter about or greater than 4 angstroms; and
d is an integer representing the charge of B'.
The improved catalysts are prepared by combining at least two components. The first component is a bis(cyclopentadienyl) derivative of a Group IV-B metal compound containing at least one ligand which will combine with the second component or at least a portion thereof such as a cation portion thereof. The second component is an ion-exchange compound comprising a cation which will irreversibly react with at least one ligand contained in said Group IV-B metal compound (first component) and a non-coordinating anion.
The cation portion of the second component may comprise a wide variety species which are known to abstract anionic ligands bound to early transition metals including Bronsted acids such as protons or protonated Lewis bases or, reducable Lewis acids such as ferricinium, tropylium, triphenylcarbenium or silver cations.
The key to proper anion design for the second component requires that the anionic complex is labile and stable toward reactions with the cationic metallocene in the final catalyst species. We have discovered that anions which are stable toward reactions with water or Bronsted acids and which do not have acidic protons located on the exterior of the anion (i.e. anionic complexes which do not react with strong acids or bases) possess the stability necessary to qualify as a stable anion for the catalyst system. The properties of the anion which are important for maximum lability include overall size, and shape (i.e. large radius of curvature), and nucleophilicty. Using these guidelines one can use the chemical literature to choose non-coordinating anions which can serve as components in the catalyst system. In general, suitable anions for the second component may be any stable and bulky anionic complex having the following molecular attributes: 1) the anion should have a molecular diameter about or greater than 4 angstroms; 2) the anion should form stable salts with reducible Lewis Acids and protonated Lewis bases; 3) the negative charge on the anion should be delocalized over the framework of the anion or be localized within the core of the anion; 4) the anion should be a relatively poor nucleophile; and 5) the anion should not be a powerful reducing or oxidizing agent. Anions meeting these criteria--such as polynuclear boranes, carboranes, metallacarboranes, polyoxoanions and anionic coordination complexes are well described in the chemical literature. Upon combination of the first and second components, the cation of the second component reacts with one of the ligands of the first component, thereby generating an ion pair consisting of a Group IV-B metal cation and the aforementioned anion, which anion is compatible with and noncoordinating towards the Group IV-B metal cation formed from the first component. The anion of the second compound must be capable of stabilizing the Group IV-B metal cation without interfering with the Group IV-B metal cation's ability to function as a catalyst and must be sufficiently labile to permit displacement by an olefin, diolefin or an acetylenically unsaturated monomer during polymerization. For example, Kochmann and Wilson have reported in J. Chem. Soc., Chem. Comm., 1986, pp. 1610-1611) that bis(cyclopentadienyl)titanium dimethyl reacts with tetrafluoroboric acid to form bis(cyclopentadienyl)titanium methyl tetrafluoroborate. The anion is, however, insufficiently labile to be displaced by ethylene in large part due to its small overall molecular size.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a room temperature 1 H NMR spectrum of the bottom phase collected from the reaction of bis(cyclopentadienyl)hafnium dimethyl [Cp 2 HfMe 2 ] with one equivalent of N,N-dimethylanilium tetra(pentafluorophenyl)boron [HDMA][B(pfp) 4 ].
FIG. 2 is a 1 H NMR spectrum of the bottom phase, as per FIG. 1, wherein the sample was maintained at 0C.
FIG. 3 is a heteroneuclear correlation spectroscopy spectrum, 1 H- 13 C COSY, of the bottom phase as per FIG. 1.
FIG. 4 is a 13 C NMR spectrum of a freshly prepared sample of [Cp 2 HfMe(DMA)] + [B(pfp) 4 ] - in d 8 -toluene.
FIG. 5 is a 13 C NMR spectrum of the sample of FIG. 4 after 18 hours at ambient temperature.
FIG. 6 is a high field 13 C NMR spectra of [Cp 2 HfMe(DMA)] + [B(pfp) 4 ] - which has been reacted with zero, one and two equivalents of Cp 2 HfMe 2 .
FIG. 7 is a 13 C NMR spectrum of bis(t-butylcyclopentadienyl)hafnium dimethyl [hereafter ( t Bu-Cp) 2 HfMe 2 ].
FIG. 8 is a 13 C NMR spectrum of a catalyst prepared by reacting ( t Bu-Cp) 2 HfMe 2 with one equivalent of [HDMA][B(pfp) 4 ].
FIG. 9 is an 13 C NMR spectrum of a composition formed after 20 minutes of reacting bis(pentamethylcyclopentadienyl)hafnium dimethyl (hereafter (C 5 Me 5 ) 2 HfMe 2 ) with one equivalent of [HDMA][(B(pfp) 4 )].
FIG. 10 is an 13 C NMR spectrum of the composition of FIG. 9 taken 20 hours after beginning the reaction.
FIG. 11 is a 13 C NMR spectrum of the product resulting from the reaction of bis(cyclopentadienyl)zirconium dimethyl [hereafter Cp 2 ZrMe 2 ] with [HDMA][B(pfp) 4 ] collected 20 minutes after the beginning of reaction.
FIG. 12 is a 13 C NMR spectrum of the product resulting from the reaction of FIG. 11 collected at 2.5 hours after the beginning of the reaction.
FIG. 13 is a 13 C NMR spectrum of the produce resulting from the reaction of Cp 2 ZrMe 2 with tributylammonium tetra(pentafluorophenyl)boron (hereafter [Bu3NH][B(pfp) 4 ]) collected 20 minutes after reaction.
FIG. 14 is a 13 C NMR spectrum of the product of FIG. 13 collected 20 hours after reaction.
DETAILED DESCRIPTION OF THE INVENTION
The improved catalysts can be prepared by combining at least one first compound which is a bis(cyclopentadienyl) derivative of a metal of the Group IV-B of the Periodic Table of the Elements containing at least one ligand which will react with an acidic hydrogen atom (i.e., proton) and at least one second compound which is a salt comprising a cation capable of donating a proton which will irreversibly combine with said at least one ligand (substituent) liberated by said Group IV-B metal compound and an anion which is either a single coordination complex comprising a plurality of lipophilic radicals covalently coordinated to and shielding a central formally charge-bearing metal or metalloid atom or an anion comprising a plurality of boron atoms such as polyhedral boranes, carboranes and metallacarboranes, which anion is both bulky and labile, compatible with and noncoordinating toward the Group IV-B metal cation formed from the first component, and capable of stabilizing the Group IV-B metal cation without interfering with said Group IV-B metal cation's ability to polymerize α-olefins, diolefins and/or acetylenically unsaturated monomers.
All reference to the Periodic Table of the Elements herein shall refer to the Periodic Table of the Elements, published by CRC Press, Inc., 1984. Also, any reference to a Group or Groups shall be to the Group or Groups as reflected in this Periodic Table of the Elements. Hereafter, the bis(cyclopentadienyl) Group IV-B metal compound may be referred to as a "metallocene": wherein the metal is titanium the compound may be referred to as a "titanocene"; when zirconium as a "zirconocene"; and when hafnium as a "hafnocene." The second component, which by reaction with the metallocene activates it to a catalytically active complex, may hereafter be referred to as an "activator compound." The second component, or activator compound, is comprised of a cation and an anion, which anion is compatible with and non-coordinating to the Group IV-B metal cation formed by reaction between the first and second components.
As used herein with reference to the initial activator compound or the ionic composition which results from the reaction of a metallocene and an activator compound, the recitation "compatible noncoordinating anion" means an anion which either does not coordinate to the Group IV-B metal cation or which is only weakly coordinated to said cation thereby remaining sufficiently labile to be displaced by a neutral Lewis base. The recitation "compatible noncoordinating anion" specifically refers to an anion which when functioning as a stabilizing anion in the catalyst system of this invention does not transfer an anionic substituent or fragment thereof to Group IV-B metal cation thereby forming a neutral four coordinate metallocene and a neutral metal or metalloid byproduct. Compatible anions are anions which are not degraded to neutrality when the initially formed complex decomposes. The recitation "metalloid" as used herein, includes nonmetals such as boron, phosphorus and the like which exhibit semi-metallic characteristics.
The Group IV-B metal compounds; i.e., titanium, zirconium and hafnium metallocene compounds, useful as first compounds in the preparation of the improved catalyst of this invention are bis(cyclopentadienyl) derivatives of titanium, zirconium and hafnium in which one or both of the two non-cyclopentadienyl ligands bonded to the metal center are hydrolyzable by water. In general, useful titanocenes, zirconocenes and hafnocenes may be represented by the following general formulae:
(A--Cp)MX.sub.1 X.sub.2 (3)
(A--Cp)MX'.sub.1 X'.sub.2 (4)
(A--Cp)ML (5)
(Cp')(CpR)MX.sub.1 (6)
Wherein "Cp" represents a cyclopentadienyl radical which may be substituted or unsubstituted, and:
(A--Cp) is either (Cp)(Cp') or Cp--A'--Cp' and Cp and Cp' are the same or different cyclopentadienyl ring substituted with from zero to five substituent groups S, and each substituent group S is, independently, a radical which can be hydrocarbyl, substituted-hydrocarbyl, halocarbyl, substituted-halocarbyl, hydrocarbyl-substituted organometalloid, halocarbyl-substituted organometalloid, or halogen radicals (the size of the radicals need not be limited to maintain catalytic activity, however, generally the radical will be a C 1 to C 20 radical) or Cp and Cp' are a cyclopentadienyl ring in which any two adjacent R groups are joined forming a C 4 to C 20 ring to give a saturated or unsaturated polycyclic cyclopentadienyl ligand such as indenyl, tetrahydroindenyl, fluorenyl, or octahydrofluorenyl and A' is a bridging group which restricts rotation of the two Cp-groups; M is titanium, zirconium or hafnium; L is an olefin, diolefin or aryne ligand; X 1 and X 2 are, independently, selected from the group consisting of hydride radicals, hydrocarbyl radicals, halocarbyl, substituted-hydrocarbyl radicals, substituted-halocarbyl radicals, hydrocarbyl-substituted organometalloid radicals, halocarbyl-substituted organometalloid radicals; X' 1 and X' 2 are joined and bound to the metal atom to form a metallacycle, in which the metal atom, X' 1 and X' 2 form a hydrocarbocyclic ring containing from about 3 to about 20 carbon atoms; and S is a substituent, preferably a hydrocarbyl substituent, on one of the cyclopentadienyl radicals which is also bound to the metal atom.
Each carbon atom in the cyclopentadienyl radical ("Cp") may be, independently, unsubstituted or substituted with the same or a different radical group which is a hydrocarbyl, substituted-hydrocarbyl, halocarbyl, substituted-halocarbyl hydrocarbyl radicals in which adjacent substituents are joined to form a ring of 4 to 10 or more carbon atoms, hydrocarbyl- and halocarbyl-substituted organometalloid radicals, and halogen radicals. Suitable hydrocarbyl and substituted-hydrocarbyl radicals, which may be substituted for at least one hydrogen atom in a cyclopentadienyl radical include straight and branched alkyl radicals, cyclic hydrocarbon radicals, alkyl-substituted cyclic hydrocarbon radicals, aryl substituted radicals and alkyl aryl-substituted radicals. Similarly, and when X 1 and/or X 2 is a hydrocarbyl or substituted-hydrocarbyl radical, each may, independently, contain from 1 to about 20 carbon atoms and be a straight or branched alkyl radical, a cyclic hydrocarbyl radical, an alkyl-substituted cyclohydrocarbyl radical, an aryl radical or an alkyl alkyl-substituted radical. Suitable organometalloid radicals include mono-, di- and trisubstituted organometalloid radicals. More particularly, suitable organometalloid radicals include trimethylsilyl, triethylsilyl, ethyldimethylsilyl, methyldiethylsilyl, triphenylgermyl, trimethylgermyl and the like.
Illustrative, but not limiting examples of bis(cyclopentadienyl)zirconium compounds which may be used in the preparation of the improved catalyst of this invention are dihydrocaryl-substituted bis(cyclopentadienyl)zirconium compounds such as bis(cyclopentadienyl)zirconium dimethyl, bis(cyclopentadienyl)zirconium diethyl, bis(cyclopentadienyl)zirconium dipropyl, bis(cyclopentadienyl)zirconium dibutyl, bis(cyclopentadienyl)zirconium diphenyl, bis(cyclopentadienyl)zirconium dineopentyl, bis(cyclopentadienyl)zirconium di(m-tolyl), bis(cyclopentadienyl)zirconium di(p-tolyl) and the like; (monohydrocarbyl-substituted cyclopentadienyl)zirconium compounds such as (methylcyclopentadienyl) (cyclopentadienyl) and bis(methylcyclopentadienyl)zirconium dimethyl, (ethylcyclopentadienyl) (cyclopentadienyl) and bis(ethylcyclopentadienyl)zirconium dimethyl, (propylcyclopentadienyl) (cyclopentadienyl) and bis(propylcyclopentadienyl)zirconium dimethyl, (n-butylcyclopentadienyl) (cyclopentadienyl) and bis(n-butylcyclopentadienyl)zirconium dimethyl, (t-butylcyclopentadienyl) (cyclopentadienyl) and bis(t-butylcyclopentadienyl)zirconium dimethyl, (cyclohexylmethylcyclopentadienyl) (cyclopentadienyl) and bis(cyclohexylmethylcyclopentadienyl)zirconium dimethyl, (benzylcyclopentadienyl)(cyclopentadienyl) and bis(benzylcyclopentadienyl)zirconium dimethyl, (diphenylmethylcyclopentadienyl)(cyclopentadienyl) and bis(diphenylmethylcyclopentadienyl)zirconium dimethyl, (methylcyclopentadienyl)(cyclopentadienyl) and bis(methylcyclopentadienyl)zirconium dihydride, (ethylcyclopentadienyl)(cyclopentadienyl) and bis(cyclopentadienyl)zirconium dihydride, (propylcyclopentadienyl)(cyclopentadienyl) and bis(propylcyclopentadienyl)zirconium dihydride, (n-butylcyclopentadienyl)(cyclopentadienyl) and bis(n-butylcyclopentadienyl)zirconium dihydride, (t-butylcyclopentadienyl)(cyclopentadienyl) and bis(t-butylcyclopentadienyl)zirconium dihydride, (cyclohexylmethylcyclopentadienyl)(cyclopentadienyl) and bis(cyclohexylmethylcyclopentadienyl)zirconium dihydride, (benzylcyclopentadienyl)(cyclopentadienyl) and bis(benzylcyclopentadienyl)zirconium dihydride, (diphenylmethylcyclopentadienyl)(cyclopentadienyl) and bis(diphenylmethylcyclopentadienyl)zirconium dihydride and the like; (polyhydrocarbyl-substituted-cyclopentadienyl)zirconium compounds such as (dimethylcyclopentadienyl)(cyclopentadienyl) and bis(dimethylcyclopentadienyl)zirconium dimethyl, (trimethylcyclopentadienyl)(cyclopentadienyl) and bis(trimethylcyclopentadienyl)zirconium dimethyl, (tetramethylcyclopentadienyl)(cyclopentadienyl) and bis(tetramethylcyclopentadienyl)zirconium dimethyl, (permethylcyclopentadienyl)(cyclopentadienyl) and bis(permethylcyclopentadienyl)zirconium dimethyl, (ethyltetramethylcyclopentadienyl)(cyclopentadienyl) and bis(ethyltetramethylcyclopentadienyl)zirconium dimethyl, (indenyl)(cyclopentadienyl) and bis(indenyl)zirconium diemthyl, (dimethylcyclopentadienyl)(cyclopentadienyl) and bis(dimethylcyclopentadienyl)zirconium dihydride, (trimethylcyclopentadienyl)(cyclopentadienyl) and bis(trimethylcyclopentadienyl)zirconium dihydride, (tetramethylcyclopentadienyl)(cyclopentadienyl) and bis(tetramethylcyclopentadienyl)zirconium dihydride, (permethylcyclopentadienyl)(cyclopentadineyl) and bis(permethylcyclopentadienyl)zirconium dihydride, (ethyltetramethylcyclopentadienyl)(cyclopentadienyl) and bis(ethyltetramethylcyclopentadienyl)zirconium dihydride, (indenyl)(cyclopentadienyl) and bis(indenyl)zirconium dihydride, (metalloid hydrocarbyl-substituted cyclopentadienyl)zirconium compounds such as (trimethylsilylcyclopentadienyl)(cyclopentadienyl) and bis(trimethylsilylcyclopentadienyl)zirconium dimethyl, (trimethylgermylcyclopentadienyl)(cyclopentadienyl) and bis(trimethylgermylcyclopentadienyl)zirconium dimethyl, (trimethylplumbylcyclopentadieny)(cyclopentadienyl) and bis(trimethylplumbylcyclopentadienyl)zirconium dimethyl, (trimethylsilylcyclopentadienyl)(cyclopentadienyl) and bis(trimethylsilylcyclopentadienyl)zirconium dihydride, (trimethylgermylcyclopentadienyl)(cyclopentadienyl) and bis(trimethylgermycyclopentadienyl)zirconium dihydride, (trimethylstannylcyclopentadienyl)(cyclopentadienyl) and bis(trimethylstannycyclopentadienyl)zirconium dihydride, (trimethylplumbylcyclopentadienyl)(cyclopentadienyl) and bis(trimethylplumbylcyclopentadienyl)zirconium dihydride and the like; (halocarbyl-substituted-cyclopentadienyl)zirconium compounds such as (trifluoromethylcyclopentadienyl)(cyclopentadienyl) and bis(trifluoromethylcyclopentadienyl)zirconium dimethyl (trifluoromethylcyclopentadienyl)(cyclopentadienyl) and bis(trifluoromethylcyclopentadienyl)zirconium dihydride and the like; silyl-substituted bis(cyclopentadienyl) zirconium compounds such as bis(cyclopentadienyl) (trimethylsilyl)(methyl)zirconium, bis(cyclopentadienyl)(triphenylsilyl)(methyl)zirconium, bis(cyclopentadienyl)[tris(dimethylsilyl)silyl](methyl)zirconium, bis(cyclopentadienyl)(trimethylsilyl)(tris(trimethylsilyl)methyl)zirconium, bis(cyclopentadienyl)(trimethylsilylbenzyl) and the like; (bridged-cyclopentadienyl)zirconium compounds such as methylene bis(cyclopentadienyl)zirconium dimethyl, methylene(cyclopentadienyl)zirconium dimethyl, ethylene bis(cyclopentadienyl)zirconium dimethyl, dimethylsilyl bis(cyclopentadienyl)zirconium dihydride, ethylene bis(cyclopentadienyl)zirconium dihydride and dimethylsilyl bis(cyclopentadienyl)zirconium dihydride and the like; chiral and C 2 -symmetion compounds; "zirconacycles"; asymmetrically bridged-dicyclopentadienyl compounds such as methylene(cyclopentadienyl)(1-fluorenyl)zirconium dihydride, isopropyl(cyclopentadienyl)(1-fluorenyl)zirconium dimethyl, isopropyl(cyclopentadienyl)(1-octahydro-fluorenyl)zirconium dimethyl, dimethylsilyl(methylcyclopentadienyl)(1-fluorenyl) zirconium dihydride, methylene(cyclopentadienyl(tetramethylcyclopentadienyl)zirconium dimethyl and the like: racemic and meso isomers of symmetrically bridged substituted dicyclopentadienyl compounds such as ethylenebis(indenyl)zirconium dimethyl, dimethylsilybis(indenyl)zirconium dimethyl, ethylenebis(tetrahydroindenyl)zirconium dimethyl, dimethylsilybis(3-trimethylsilylcyclopentadienyl)zirconium dihydride and the like; zirconacycles such as bis(pentamethylcyclopentadienyl)zirconacyclobutane, bis(pentamethylcyclopentadienyl)zirconacyclopentane, bis(cyclopentadienyl)zirconaindane, 1-bis(cyclopentadienyl)zircona-3-dimethylsilacyclobutane and the like; olefin, diolefin and aryne ligand substituted bis(cyclopentadienyl)zirconium compounds such as bis(cyclopentadienyl)(1,3-butadiene)zirconium, bis(cyclopentadienyl)(2,3-dimethyl-1,3-butadiene)zirconium, bis(pentamethylcyclopentadienyl)(benzyne)zirconium and the like; (hydrocarbyl)(hydride) bis(cyclopentdienyl)zirconium compounds such as bis(pentamethylcyclopentadienyl)zirconium (phenyl) (hydride), bis(pentamethylcyclopentadienyl)zirconium (methyl)(hydride) and the like; and bis(cyclopentadienyl)zirconium compounds in which a substituent on the cyclopentadienyl radical is bound to the metal such as (pentamethylcyclopentadienyl)(tetramethylcyclopentadienylmethylene)zirconium hydride, (pentamethylcyclopentadienyl)(tetramethylcyclopentadienylmethylene)zirconium phenyl and the like.
A similar list of illustrative bis(cyclopentadienyl) hafnium and bis(cyclopentadienyl)titanium compounds could be made, but since the lists would be nearly identical to that already presented with respect to bis(cyclopentadienyl)zirconium compounds, such lists are not deemed essential to a complete disclosure. Other bis(cyclopentadienyl)hafnium compounds and other bis(cyclopentadienyl)titanium compounds as well as other bis(cyclopentadienyl)zirconium compounds which are useful in the catalyst compositions of this invention will, of course, be apparent to those skilled in the art.
Compounds useful as a second component, or as the activator compound, in the preparation of the catalyst of this invention comprise a cation, preferably are a Bronsted acid capable of donating a proton, and a compatible noncoordinating anion containing a single coordination complex comprising a charge-bearing metal or metalloid core which is relatively large (bulky), capable of stabilizing the active catalyst species (the Group IV-B cation) which is formed when the metallocene and activator compounds are combined, and said anion is sufficiently labile to be displaced by olefinic, diolefinic and acetylenically unsaturated substrates or other neutral Lewis bases such as ethers, nitriles and the like. Any metal or metalloid capable of forming a coordination complex which is resistant to degradation by water (or other Bronsted or Lewis Acids) may be used or contained in the anion of the second activator compound. Suitable metals include, but are not limited to, aluminum, gold, platinum and the like. Suitable metalloids include, but are not limited to, boron, phosphorus, silicon and the like.
Compounds containing anions which comprise coordination complexes containing a single metal or metalloid atom are, of course, well known and many, particularly compounds containing a single boron atom in
the anion portion, are available commercially. In light of this, salts containing anions comprising a coordination complex containing a single boron atom are preferred. In general, the second activator compounds useful in the preparation of the catalysts of this invention may be represented by the following general formula:
(L'--H).sup.+ ].sup.d [(M').sup.m+ Q.sub.1 Q.sub.2 . . . Q.sub.n ].sup.d-(7)
wherein:
L' is a neutral Lewis base;
H is a hydrogen atom;
(L'--H) is a Bronsted acid;
M' is a metal or metalloid;
Q 1 to Q n are, independently, bridged or unbridged hydride radicals, dialkylamido radicals, alkoxide and aryloxide radicals, hydrocarbyl and substituted-hydrocarbyl radicals, halocarbyl and substituted halocarbyl radicals, and hydrocarbyl- and halocarbyl-substituted organometalloid radicals and any one, but not more than one, of Q 1 to Q n may be a halide radical;
m is an integer representing the formal valence charge of M';
n is the total number of ligands Q; and
d is an integer representing the total charge on the anion.
Second activator compounds comprising boron which are particularly useful in the preparation of catalysts of this invention are represented by the following general formula:
[L'--H].sup.+ [BAr.sub.1 Ar.sub.2 X.sub.3 X.sub.4 ].sup.- (8)
wherein:
L' is a neutral Lewis base;
H is a hydrogen atom;
[L'--H] + is a Bronsted acid;
B is boron in a valence state of 3 + ;
Ar 1 and Ar 2 are the same or different aromatic or substituted-aromatic hydrocarbon radicals and may be linked to each other through a stable bridging group; and
X 3 and X 4 are, independently, hydride radicals, halide radicals, with the proviso that only X 3 or X 4 will be halide, hydrocarbyl radicals, substituted-hydrocarbyl radicals, halocarbyl radicals, substituted-halocarbyl radicals, hydrocarbyl- and halocarbyl-substituted organometalloid radicals, dialkylamido radicals, and alkoxy and aryloxy radicals.
In general, Ar 1 and Ar 2 may, independently, be any aromatic or substituted-aromatic hydrocarbon radical. Suitable aromatic radicals include, but are not limited to, phenyl, naphthyl and anthracenyl radicals. Suitable substituents on useful substituted-aromatic hydrocarbon radicals, include, but are not necessarily limited to, hydrocarbyl radicals, organometalloid radicals, alkoxy radicals, alkylamido radicals, fluoro and fluorohydrocarbyl radicals and the like such as those useful as X 3 or X 4 . The substituent may be ortho, meta or para, relative to carbon atom bonded to the boron atom. When either or both X 3 and X 4 are a hydrocarbyl radical, each may be the same or a different aromatic or substituted-aromatic radical as are Ar 1 and Ar 2 , or the same may be a straight or branched alkyl, alkenyl or alkynyl radical, a cyclic hydrocarbon radical or an alkylsubstituted cyclic hydrocarbon radical. X 3 and X 4 may also, independently, be alkoxy or dialkylamido radicals, hydrocarbyl radicals and organometalloid radicals and the like. As indicated supra, Ar 1 and Ar 2 may be linked to each other. Similarly, either or both of Ar 1 and Ar.sub. 2 could be linked to either X 3 or X 4 . Finally, X 3 and X 4 may also be linked to each other through a suitable bridging group.
Illustrative, but not limiting, examples of boron compounds which may be used as an activator component in the preparation of the improved catalysts of this invention are trialkyl-substituted ammonium salts such as triethylammonium tetra(phenyl)boron, tripropylammonium tetra(phenyl)boron, tri(n-butyl)ammonium tetra(phenyl)boron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o-tolyl)boron, tributylammonium tetra(pentafluorophenyl)boron, tripropylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(m,m-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetra(pentafluorophenyl)boron, tri(n-butyl)ammonium tetra(o-tolyl)boron and the like; N,N-dialkyl anilinium salts such as N,N-dimethylanilinium tetra(phenyl)boron, N,N-diethylanilinium tetra(phenyl)boron, N,N-2,4,6-pentamethylanilinium tetra(phenyl)boron and the like; dialkyl ammonium salts such as di- (isopropyl)ammonium tetra(pentafluorophenyl)boron, dicyclohexylammonium tetra(phenyl)boron and the like; and triaryl phosphonium salts such as triphenylphosphonium tetra(phenyl)boron, tri(methylphenyl)phosphonium tetra(phenyl)boron, tri(dimethylphenyl)phosphonium tetra(phenyl)boron and the like.
Similar lists of suitable compounds containing other metals and metalloids which are useful as activator components could be made, but such lists are not deemed necessary to a complete disclosure. In this regard, it should be noted that the foregoing list is not intended to be exhaustive and other boron compounds that would be useful as well as useful compounds containing other metals or metalloids would be readily apparent, from the foregoing general equations, to those skilled in the art.
In general, and while most metallocenes identified above may be combined with most activator compounds identified above to produce an active olefin polymerization catalyst, it is important to continued polymerization operations that either the metal cation initially formed from the metallocene, or a decomposition product thereof, be a relatively stable catalyst. It is also important that the anion of the activator compound be chemically stable and bulky. Further, when the cation of the activator component is a Bronsted acid, it is important that the acidity of the activator compound be sufficient, relative to the metallocene, to facilitate the needed proton transfer. Conversely, the basicity of the metal complex must also be sufficient to facilitate the needed proton transfer. In general, metallocenes in which the non-cyclopentadienyl ligands can be hydrolyzed by aqueous solutions can be considered suitable metallocenes for forming the catalysts described herein, because water (our reference Bronsted acid) is a weaker acid than the ammonium ions used as cation in our preferred ion-exchange reagents. This concept allows on of ordinary skill in the art to choose useful metallocene components because stability to water is a basic chemical property easily determined experimentally or by using the chemical literature.
The chemical reactions which occur upon combination of a first metallocene compound with a second activator compound may be represented by reference to the general formulae set forth herein as follows:
(A--Cp)MX.sub.1 X.sub.2 +[L'--H].sup.+ [B'].sup.- [(A--Cp)MX.sub.1 ].sup.+ [B'].sup.- +HX.sub.2 +L'
or
[(A--Cp)MX.sub.2 ].sup.+ [B'].sup.- +HX.sub.1 +L' (A)
(A--Cp)MX'.sub.1 X'.sub.2 +(L'--H].sup.+ [B'].sup.- [(A--Cp)MX'.sub.1 X'.sub.2 H].sup.+ [B'].sup.- +L'
or
[(A--Cp)MX'.sub.2 X'.sub.1 H].sup.+ [B'].sup.- +L' (B)
(A--Cp)ML+[L'--H].sup.+ [B'].sup.- [(A--Cp)M(LH)].sup.+ [B']-+L'(C)
(Cp*)(RCp)MX.sub.1 +[L'--H].sup.+ [B'].sup.- [(Cp*)(HR--Cp)MX.sub.1 ].sup.+ [B'].sup.- +L'
or
[(Cp*)(R--Cp)M].sup.+ [B'].sup.- +HX.sub.1 +L' (D)
In the foregoing reaction equations, the letters A-D correspond to the numbers 1-4, respectively, set forth in combination with the general equations for useful metallocene compounds. B' represents a compatible ion corresponding to the general formulae outlined in formulae 7 and 8 above. When the metallocene and activator components used to prepare the improved catalysts of the present invention are combined in a suitable solvent or diluent, all or a part of the cation of the activator (the acidic proton) combines with one of the substituents on the metallocene compound. In the case where the metallocene component has a formula corresponding to that of general formula 3, a neutral compound is liberated, which neutral compound either remains in solution or is liberated as a gas. In this regard, it should be noted that if either X 1 or X 2 in the metallocene component is a hydride, hydrogen gas may be liberated. Similarly, if either X 1 or X 2 is a methyl radical, methane may be liberated as a gas. In the cases where the first component has a formula corresponding to those of general formulae 4, 5 or 6 (optional), one of the substituents on the metallocene component is protonated but no substituent is liberated. In general, the rate of formation of the products in the foregoing reaction equations will vary depending upon the choice of the solvent, the acidity of the [L'--H] + selected, the particular L', the anion, the temperature at which the reaction is completed and the particular cyclopentadienyl derivative of the metal selected.
As indicated, the improved catalyst compositions of the present invention will, preferably, be prepared in a suitable solvent or diluent. Suitable solvents or diluents include any of the solvents known in the prior art to be useful as solvents in the polymerization of olefins, diolefins and acetylenically unsaturated monomers. Suitable solvents, then, include, but are not necessarily limited to, straight and branched-chain hydrocarbons such as isobutane, butane, pentane, hexane, heptane, octane and the like; cyclic and alicyclic hydrocarbons such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane and the like and aromatic and alkyl-substituted aromatic compounds such as benzene, toluene, xylene and the like. Suitable solvents also include liquid olefins which may act as monomers or comonomers including ethylene, propylene, butadiene, cyclopentene, 1-hexane, 3-methyl-1-pentene, 4-methyl-1-pentene, 1,4-hexadiene, 1-octene, 1-decene and the like. Suitable solvents further include basic solvents which are not generally useful as polymerization solvents when conventional Ziegler-Natta type polymerization catalysts are used such as chlorobenzene.
As before discussed, the active catalyst species of the catalyst of this invention is relatively stable and is not subject to the ion equilibrium deactivation as are alumoxane cocatalyzed metallocene catalyst systems. Unlike metallocene-alumoxane catalyst systems wherein, to obtain a practical level of catalyst productivity it is generally required to use an amount of alumoxane, measured as aluminum atom, to provide a ratio of Al:transition metal well in excess of 1000:1; catalysts of this invention which are highly productive may be prepared at ratios of metallocene to activator of 10:1 to about 1:1, preferably about 3:1 to 1:1.
In the process of characterizing the reaction products isolated from the reaction of a wide variety of first and second components we have identified several classes of catalytically active ionic complexes. In all cases the initial activation reaction produces a three coordinate hydrido- or hydrocarbyl-cation as indicated in the general formulae set forth in A, B, C and D, but the structure of the final catalyst species depends on such factors as (1) the metallocene used and the degree to which the cyclopentadienyl ligands of such metallocenes are substituted; (2) the nature of the anion moiety of the second or activator compound and the degree and type of substitution on such anions; (3) the nature of the cation moiety of the second or activator compound--particularly the molecular size of the neutral Lewis base which is liberated from such cation upon loss therefrom of a proton; and (4) the ratios at which the metallocene and activator compound are employed. Each of the structurally distinct ionic complexes described below represent a general class of useful and novel catalytically active species which are commonly produced in the reaction of first and second components described in this invention.
With respect to the combination of a metallocene and an activator compound to form a catalyst of this invention, it should be noted that the two compounds combined for preparation of the active catalyst must be selected so as to avoid transfer of a fragment of the activator compound anion, particularly an aryl group, to the metallocene metal cation, thereby forming a catalytically inactive species. When anions consisting of hydrocarbyl anions are used, there are several means of preventing anion degradation and formation of inactive species. One method is to carry out the protonolysis process in the presence of small Lewis bases such as tetrahydrofuran. Discrete complexes can be isolated from these reactions, but the Lewis base is insufficiently labile to be displaced readily by olefin monomers, resulting in, at best, catalysts of very low activity. Another method of avoiding deleterious anion degradation is by steric hindrance. Anions of the second component which contain aryl groups can be made more resistant to degradation by introducing substituents in the ortho positions of the phenyl rings. While active metallocene polymerization catalysts can be generated by this method, the complex reaction chemistry often prevents characterization of the catalytically active species. Steric hindrance can also result form substitutions on the cyclopentadienyl rings of the metallocene component. Hence, wherein the metallocene used is a bis(peralkyl-substituted cyclopentadienyl) Group IVB metal compound, the high degree of substitution on the cyclopentadienyl ring creates sufficient bulkiness that the Lewis base generated by the protonolysis reaction not only cannot coordinate to the metal but also polyarylborate anions without substituents on the aryl rings do not transfer aryl fragments to generate catalytically inactive species. Under these conditions, as illustrated by Examples 1, 4, 10 and 22, the most stable species formed is a zwitterion.
This behavior is best exemplified in a metallocene comprised of bis(peralkylcyclopentadienyl) ligands wherein a tetraphenyl borate is used as the anion of the activator compound. For example, the reaction of Cp* 2 ZrMe 2 (where Cp=Me 5 Cp) and [Bu 3 NH] + [B(Ph 4 )] - (where Ph, =phenyl or para-alkylphenyl with hydrogen or an alkyl group in the para-position) in toluene gives [Cp* 2 ZrMe] + [B(Ph) 4 ] which is unstable and decomposes by loss of methane to give a single catalytically active product. The deep red product has been fully characterized by NMR spectroscopy and single crystal x-ray diffraction. The general structure of this zwitterionic catalyst of this type is shown below: ##STR1## wherein:
Cp* is a peralkyl-substituted cyclopentadienyl radical wherein each of said alkyl substitutions may be the same or a different alkyl radical, preferably the same or a different C 1 -C 6 alkyl radical, most preferably the same or a different C 1 -C 4 alkyl radical; B is boron; Zr is zirconium; Ph' is a phenyl or alkyl-substituted phenyl radical and each of the 3 Ph's may be the same or different, the alkyl substitutions preferably being C 1 -C 6 , most preferably C 1 -C 4 .
Addition of excess hydrogen gas to a toluene solution containing the above-identified pentamethyl-substituted
cyclopentadienyl zwitterionic catalyst causes a rapid reaction as evidenced by a color change from red to yellow, and, in concentrated solutions, the formation of a yellow precipitate. Removal of hydrogen from the system regenerates the original zwitterionic catalyst in high yield. It is believed that the reaction of hydrogen with the zwitterionic catalyst leads to the formation of [Cp* 2 ZrH] + [B(Ph') 4 ]. The reversible nature of this reaction along with other spectroscopic evidence suggests that the hydride cation is in chemical equilibrium with the zwitterionic species.
Consistent with the foregoing, stable polymerization catalysts have been prepared when bis(permethylcyclopentadienyl) zirconium dimethyl has been reacted with tri(n-butyl)ammonium tetra(phenyl)boron, tri(n-butyl)ammonium tetra(p-tolyl)boron and tri(n-butyl)ammonium tetra(p-ethylphenyl)boron. A stable polymerization catalyst has also been prepared when bis(ethyltetramethylcyclopentadienyl)zirconium dimethyl was reacted with tri(n-butyl)ammonium tetra(p-tolyl)boron. In each of these cases, the stable polymerization catalyst was prepared by adding the reactants into a suitable aromatic solvent at a temperature within the range from about 0C. to about 100C. It appears clear that stable zwitterionic polymerization catalysts can also be prepared using bis(perhydrocarbylcyclopentadienyl)zirconium dialkyls and dihydrides in combination with ammonium salts of an unsubstituted or p-substituted-tetra(aryl)boron anion. Another means of rendering the anion of the activator compound more resistant to degradation is afforded by fluoride substitution, especially perfluoro substitution, in the anion thereof. One class of suitable non-coordinating anions can be represented by the formula [B(C 6 F 5 ) 3 Q] - where Q is a monoanionic non-bridging radical as described above. The preferred anion of the activator compound of this invention, tetra(pentafluorophenyl)boron, hereafter referred to for convenience by the notation [B(C 6 F 5 ) 4 ] - , or [B(pfp) 4 ]--, is virtually impervious to degradation and can be used with a much wider range of metallocene cations, including those without substitution on the cyclopentadienyl rings, than anions comprising hydrocarbyl radicals. The tetra(pentafluoro) boron anion is illustrated below: ##STR2##
Since this anion has little or no ability to coordinate to the metallocene cation and is not degraded by the metallocene cation, structures of the ion-pair metallocene catalysts using the [B(pfp) 4 ] - anion depend on steric hindrance of substituents on the cyclopentadienyl rings of metallocene, the nature of the cation of the activator component, the Lewis base liberated from the protonolysis reaction, and the ratio at which the metallocene and activator component are combined. If Lewis bases other than that liberated from the proton transfer process are present, they may complex to the metal to form modified catalysts of this invention. One such modified catalyst can be represented by the formula:
{[[(A--Cp)M.sub.1 X.sub.1 ]--X.sub.7 --[(A--Cp)'M.sub.2 X.sub.6 ]].sup.+ }.sub.d [B'].sup.d- (9)
wherein:
(A--Cp) and (A--Cp)' are the same or different;
M 1 and M 2 are the same or different metal selected from the Group consisting of titanium, zirconium and hafnium;
X 1 and X 6 are independently selected from the group consisting of hydride radicals, hydrocarbyl radicals, substituted-hydrocarbyl radicals, halocarbyl radicals, substituted-halocarbyl radicals, hydrocarbyl- and halocarbyl-substituted organometalloid radicals; and
X 7 is a derivative of an X 1 or X 6 radical bridging M 1 and M 2 .
When the cation of the activator compound is one which, upon the proton reaction with the substituent of the metallocene, liberates a small neutral Lewis base, like N,N-dimethylaniline (DMA), steric hinderance usually does not prevent coordination of the neutral Lewis base to the metallocene cation.
Accordingly, there is a competition between DMA and unreacted metallocene as to which will coordinate to and stabilize the metallocene cation formed by the proton reaction between the metallocene and the activator compound. The most stable catalyst species that can be formed therefore depends upon the ratio of metallocene (M) to activator compound (A) . At a ratio of M:A of 1:1, upon completion of the proton reaction there remains no unreacted metallocene. The only neutral Lewis base remaining available to coordinate to and stabilize the metallocene cation is DMA. In such circumstances the species formed can be represented by one of three general formulae which are subsets of the general formula 2 of [(A--Cp)MX 5 L'] + as defined above: ##STR3## wherein: Z is a Group V-A element; and
R 1 to R 6 are independently hydride, hydrocarbyl, substituted-hydrocarbyl, halocarbyl, substituted-halocarbyl, hydrocarbyl-substituted organometalloid, halocarbyl-substituted organometalloid, or halide radicals.
Three distinct examples of such complexes are illustrated below, where each R' and R" is the same or different S substituent as defined above and x and y are, independently, integers from zero to five: ##STR4##
It is important to note that cations [(A--Cp)MX 5 L'] + wherein X 5 and L' are covalently bonded to each other (as in II and III) may be useful as catalysts for the modification of X 5 L'-substrates. This may be especially useful when A--Cp is a stereochemically rigid chiral ligand set.
In cases where the activator compound is used in less than a 1:1 stoichiometric amount relative to the metallocene, a corresponding amount of unreacted metallocene remains available in the system. The unreacted metallocene, although an extremely weak Lewis base, is nevertheless a Lewis base comparable in strength to DMA. The unreacted metallocene which remains in the system serves as a Lewis base source to coordinate to and stabilize the metallocene cation formed. In circumstances wherein unreacted metallocene serves to stabilize the metallocene cation, the catalytic species formed is of the general structure: ##STR5##
Accordingly, wherein the metallocene is used in excess relative to the activator compound, and the activator compound is one the cation portion of which is a small protonated Lewis base such as N,N-dimethylaniline, the relative amounts of catalyst species of formula II and IV is dictated by the equilibrium conditions then prevailing. At metallocene to activator compound ratios of 1:1 the species of formula I first forms which, at room temperature may slowly decompose to give active catalysts with structures like those of formulae II and III.
As the ratio of metallocene to activator is increased from 1:1, the equilibrium will increasingly comprise amounts of species IV. The partition between the amounts of species II and IV formed at steady state conditions appears to follow classic equilibrium behavior. The equilibrium constants will depend on the metal, the number and type of substitutions on the cyclopentadienyl rings and the relative basicity of the Lewis base L'. In order to prepare a catalyst composition which is essentially composed solely of species IV it is necessary to use an excess of metallocene to activator of greater than 1:1, preferably from about 3:1 or greater.
Wherein a catalyst is prepared using an activator compound comprising a cation of large molecular dimensions, such as a tri(n-butyl)ammonium cation, the neutral Lewis base liberated from the activator compound upon reaction with the metallocene, namely tri-n-butylamine, is too bulky to coordinate with the resulting transition metal cation of the metallocene. Accordingly, an active catalyst species in the nature of a neutral Lewis base coordinated metallocene cation cannot form. Instead, the active catalyst species initially formed is exclusively a metallocene cation dimerically coordinated with a neutral metallocene molecule, as illustrated by structure IV. The dimeric coordination occurs through a divalent hydride or through a hydrocarbyl radical at least one carbon atom of which exists in a formal 5-coordinate state. The relative stability of this dimeric catalyst species is in part dependent upon the molar ratio of metallocene to activator compound used in preparing the catalyst. Wherein a metallocene to activator compound ratio of 1:1 is employed, as a metallocene molecule reacts with an activator compound molecule to form a metallocene metal cation, that cation immediately coordinates to the best Lewis base species present in the reaction solution. Since the neutral Lewis base liberated by reaction of the activator compound is too bulky to coordinate with the neutral cation, the next best Lewis base available in solution are unreacted metallocene molecules. Hence a metallocene cation molecule immediately coordinates to an unreacted metallocene molecule to form a relatively stable dimeric species of metallocene cation. In this manner, the full equivalent of metallocene is consumed while only one half of the activator compound equivalence is consumed. Thereafter, in a kinetically slower process, the remaining unreacted one half equivalent of activator compound reacts with the dimeric species of metallocene metal cation to form an intermediate species of structure: ##STR6##
Again, since the neutral Lewis base of Bu 3 N liberated by consumption of the activator compound is too bulky to coordinate with Species V, and since there is no longer available in solution any alternative Lewis base capable of stabilizing species V, it quickly decomposes to products whose structures are as yet undetermined but which are still cationic and catalytically active.
In the case of a catalyst prepared at a ratio of from about 2:1 to 3:1, metallocene to activator compound, the dimeric form of catalyst species, species IV, may be essentially exclusively formed, and once formed is relatively stable, having a half life of several hours at room temperature.
When the catalyst is prepared in toluene a rapid reaction occurs yielding a two-phase liquid system. The upper layer is essentially pure toluene while the bottom layer is an air sensitive yellow liquid. Characterization of the catalyst species has been accomplished by an indirect method which involved reacting the yellow catalyst layer with d 8 -THF to form a d 8 -THF adduct that is soluble in THF. The catalyst structure has also been characterized by High Field NMR spectroscopy. The 1 HMR spectrum of the yellow liquid after extraction with d 8 -THF suggests that DMA which is liberated during activation is coordinated to the metal center to form a stable adduct, [Cp 2 M(CH 3 )L'][B(C 6 F 5 ) 4 ]. This is an unexpected result since tertiary amines are not good ligands for transition metal complexes.
The reaction of Cp 2 HfMe 2 (where Cp=C 5 H 5 , Me=CH 3 ) with one equivalent of [DMAH][B(pfp) 4 ] was carried out in deuterated benzene. The reaction proceeded quickly (5 minutes) to give a two phase system. The top phase is essentially pure d 6 -benzene, with a yellow bottom phase containing the catalyst and deuterated solvent. The amount of deuterated solvent in the catalyst phase is a thermodynamic property of the system and cannot be raised by adding more solvent. However, the concentration of deuterated solvent is high enough to be used as a lock solvent for NMR experiments. The room temperature 1 H NMR spectrum of the bottom phase was collected and is shown in FIG. 1. The assignments for the Cp-group (6.49 ppm), the aniline methyl groups (3.14 ppm), and the methyl group bonded to hafnium (1.39 ppm) are based on chemical shift data collected for known model compounds and their relative integrated intensities (e.g. 10:6:3). The sharp signals at 6.49, 3.14, and 1.39 ppm broaden and coalesce into multiplets as the temperature is lowered to 0° C. The low temperature 1 H NMR (0° C.) spectrum is shown in FIG. 2. The complex appearance of the 1 H NMR spectrum is due to the presence of rotomeric isomers (different orientations of the coordinated aniline ligand with respect to the metallocene framework of the basic structure--see Structure VII, below. At elevated temperatures the rate rotation about the Hf--N bond increases and the multiple signals observed for the methyl and Cp-signals coalesce into sharp singlets. The spectra demonstrate that the reaction is remarkably clean, producing one type of stable metallocene complex. The fact that the chemical shift of the aniline methyl signal is shifted downfield by 10 ppm relative to free DMA is consistent with coordination of the aniline to the cationic metal center. The chemical shift of the hafnium methyl group (44.5 ppm) is shifted downfield from neutral hafnocene methyl complexes; again, this is consistent with a cationic hafnium center. The B(pfp) 4 - carbon signals have the same pattern and chemical shift as the parent ammonium salt indicating the anion is intact and is not strongly interacting with the cationic metal center. The 1 H and 13 C NMR data are consistent with the structure shown below: ##STR7##
Heteronuclear correlation spectroscopy, 1 H- 13 C COSY, was used to confirm the assignments made. The COSY analysis determines the correlation of 13 C NMR signals to the 1 H NMR signals. In this spectrum the one dimensional 13 C spectrum appears on the horizontal axis and the 1D 1 H NMR spectrum appears on the vertical axis (the overall resolution of this spectrum is typically lower than in a 1D spectrum). The 2D COSY spectrum is a contour plot of the intensity of the cross-peaks which occur when the 1 H and 13 C signals are correlated. Correlation of the proton and carbon resonances indicates that they are directly bonded together. The two dimensional NMR technique requires long acquisition times (typically overnight). For this reason the analysis was carried out at low temperature (0° C.) to minimize thermal decomposition of the catalyst during the acquisition. The 2D COSY of the bottom phase is shown in FIG. 3. The signal assigned to Hf-Me is correlated to the proton signal at 1.4 ppm and the aniline methyl signal is correlated to the proton signal at 3.1 ppm. The three signals of the protonated ring carbons of coordinated DMA at 114, 119, and 130 are correlated to the 1 H signals at 6.8, 7.5 and 8.2 ppm, respectively. The Cp-ring carbons at 114 ppm are correlated to the 1 H Cp-signal at 6.5 ppm. Again, these correlations strongly corroborate the structure as assigned in in Structure VII. Note that the 13 C signal of the DMA carbon at 114 ppm overlaps with Cp-carbon signal, but in the COSY spectrum these signals are resolved in the second dimension.
The thermal decomposition of the hafnium DMA-adduct [Cp 2 HfMe(DMA)][B(pfp) 4 ] has been studied. A 13 C NMR spectrum of fresh [Cp 2 HfMe(DMA)][B(pfp) 4 ] in d 8 -toluene is shown in FIG. 4. The sample was stored in a N 2 atmosphere at ambient temperature, after 18 hours the spectrum shown in FIG. 5 was collected. Integration of a signal assigned to the B(pfp) 4 - anion (the reference) relative to the signal due to the methyl groups on the coordinated DMA ligand on [Cp 2 HfMe(DMA)][B(pfp) 4 ] was used to estimate the degree of decomposition of the DMA adduct. The estimated half life of [Cp 2 HfMe(DMA)][B(pfp) 4 ] is 18 hours at ambient temperatures. In the decomposition products it appears that the boron anion has not been destroyed, meaning that the metal remains cationic. Thus the decomposition of [Cp 2 HfMe(DMA)][B(pfp) 4 ] involves loss of methane and formation of new ionic products. NMR evidence shows that decomposition can give cations where the aniline ligand has been metallated as shown below in Structures VII and VIII. ##STR8##
Further possible decomposition products are those wherein, upon loss of methane, the Cp ring and/or the solvent (exemplified by benzene) become metallated as shown below in Structures IX and X. While these species have been not been produced in high yield during thermal decomposition, we have observed clear evidence for their formation in NMR experiments. The structures are catalytically active because they possess the structural features necessary for olefin polymerization: high valent (d o ), coordinatively unsaturated (formal three coordination), alkyl cations. ##STR9##
The decomposition products remain active olefin polymerization catalysts because the basic structure required for catalytic activity remains intact, i.e. three coordinate metal cation with a reactive metal-carbon sigmabond.
The high field 13 C NMR spectra of Cp 2 HfMe(DMA)][B(pfp) 4 ] reacted with zero, one and two equivalents of Cp 2 HfMe 2 are shown in FIG. 6. The NMR data suggests that Cp 2 HfMe 2 acts as a Lewis base and displaces coordinated DMA to form the dimeric cation shown below in Structure XI. ##STR10## Signals due to [Cp 2 HfMe(DMA)][B(pfp) 4 ], Cp 2 HfMe 2 and free DMA have been labeled in FIG. 6. The new signals found at 41 ppm and 23.5 ppm are assigned to the terminal and bridging methyl groups on the dimeric cation; the new signal at 112 ppm is assigned to the four equivalent Cp-rings of the dimeric cation. Further evidence for the formation of the dimeric cation involves its isolation and reaction with THF to give [Cp 2 HfMe(THF)][B(pfp) 4 ] and Cp 2 HfMe 2 in a 1:1 ratio. That the amount of dimeric cation and free DMA increases as the concentration of Cp 2 HfMe 2 increases evidences that an equilibrium exists between Cp 2 HfMe(DMA)] and the dimeric cation [Structure XI]. The Lewis base strength of DMA and Cp 2 HfMe 2 are estimated to be very close since the addition of one equivalent of Cp 2 HfMe 2 gives a nearly 50:50 mixture of the two metallocene cations.
The dimeric cation of Structure XI has been observed, isolated, and characterized and is an active catalyst.
The 13 C NMR spectrum of the reaction of one equivalent of [Bu 3 NH][B(pfp) 4 ] with Cp 2 HfMe 2 in d 6 -benzene shows the presence of the dimeric cation, free Bu 3 N and unreacted [Bu 3 NH][B(pfp) 4 ] after 20 minutes at room temperature. After two hours the dimeric cation and unreacted [Bu 3 NH][B(pfp) 4 ] disappeared and the spectrum shows free Bu 3 N and several unidentified metallocene signals. The bottom layer was quenched with d 8 -THF and the 1 H NMR spectrum was collected. The spectrum showed Cp 2 HfMe 2 , Cp 2 HfMe(THF-d 8 )][B(pfp) 4 ] and [Bu 3 NH][B(pfp) 4 ] in nearly equal molar ratios. Diagram 1 below describes an interpretation of these data. ##STR11##
Free Bu 3 N is not capable of coordinating to and stabilizing the three coordinate cation 1, and the best Lewis base in solution is unreacted Cp 2 HfMe 2 . Cp 2 HfMe 2 and Cp 2 HfMe][B(pfp) 4 ] react to form the dimeric cation discussed earlier. It has been shown that THF and the dimeric cation react to give equal molar amounts of Cp 2 HfMe(THF)][B(pfp) 4 ] and Cp 2 HfMe 2 (thus explaining the d 8 -THF quenching experiment). The rate of formation of 2 from 1 (k 2 ) is fast compared to the rate of decomposition of the three coordinate complex (k 4 ). Furthermore, the rate of protonation of 2 by the unreacted activator must be relatively slow because unreacted activator is observed even after 20 minutes by 13 C NMR. Thus, the first half of equivalent of activator is quickly consumed to form the dimeric cation. The dimeric cation slowly reacts with the remaining activator (k 3 ) to form two equivalents of "naked" cation 1 which decomposes (by reaction with solvent, other cations, the Cp-ligand and/or free amine) since there is no Lewis base in solution capable of stabilizing the system. In the decomposition products the anion is not degraded and the metal center remains cationic.
The Lewis base, L', released during catalyst activation plays an important role in determining the stability and structure of the hafnium catalyst. The three coordinate cation [Cp 2 HfMe] + thermally decomposes to give several cationic products unless there is a Lewis base present that is capable of coordinating to the cationic center. Cp 2 HfMe 2 and PhNMe 2 are sufficiently basic to stabilize the metal center and Bu 3 N is not. From an electronic point of view one would predict that Bu 3 N would coordinate more strongly to the cationic center than PhNMe 2 because PhMe 2 NH + is a much stronger Bronsted acid than Bu 3 NH + (by a factor of 10 6 ). This observation leads to the conclusion that steric factors play an important role in determining the ability of a Lewis base to coordinate to [Cp 2 HfMe] + . For this reason substituted hafnocene catalysts prepared using [DMAH][B(pfp) 4 ] were examined to determine how the number and type of substitutions affect DMA's ability to coordinate to the metal center. The 13 C NMR spectrum of ( t Bu--Cp) 2 HfMe 2 is shown in FIG. 7. As expected, three Cp-signals were observed in the aromatic region of the spectrum. The low field signal at 138 ppm is assigned to the ring carbon atom bonded to the t Bu-group; the fact that this carbon is not bonded to a proton was confirmed by DEPT NMR spectroscopy. The two signals at 108 and 109 ppm are bonded to protons and are assigned to the two sets of inequivalent carbon atoms of the Cp-ring. The signal at 38 ppm is assigned to the hafnium methyl groups based on known chemical shifts of neutral methyl hafnocene complexes. The large signal at 31 ppm is assigned to the three methyl groups on the t Bu group. The remaining signal at 32.5 ppm is the quaterary carbon on the t Bu group. The 13 C NMR spectrum of the catalyst prepared by reacting ( t Bu-Cp) 2 HfMe 2 with one equivalent of [DMAH][B(pfp) 4 ] is shown in FIG. 8. The fact that one set of t Bu signals (e.g. one quartanary carbon at 34 ppm and one t Bu-methyl signal at 31 ppm was observed suggest that the reaction produces one type of hafnium product and that the t Bu-group remains intact (e.g. the t Bu group does not react with the catalyst center to form a metallated species). The sharp signal at 48 ppm is assigned to the methyl group bonded to the cationic metal center. The relatively broad signal at 50 ppm is assigned to the two methyl groups on the coordinated amine, DMA. No evidence for the existence of free DMA (no signal at 40 ppm) was observed. The fact that the coordinated signal for the DMA methyl groups at 40 ppm is broader than normal suggests the presence of a fluxional or dynamic process which is operating near the NMR time scale. The NMR data are consistent with a structure shown below in Structure XII. Five independent Cp-carbon signals should be observed in the NMR spectrum to be consistent with this structure because the asymmetry caused by coordination of the aniline ligand destroys the plane of symmetry through the t Bu carbon of the Cp-ligands. ##STR12##
The NMR spectra of the reaction of bis(pentamethylcyclopentadienyl)zirconium dimethyl (Cp*ZrMe 2 where Cp*=C 5 Me 5 ) with one equivalent of [DMAH][B(pfp) 4 ] after 20 minutes and 20 hours at room temperature are shown in FIG. 9 and 10 respectively. The initial reaction product is unstable and decomposes into several cationic complexes. The signals between 10 and 20 ppm are assigned to the methyl groups attached to Cp* ligands; the fact that there are at least 6 different singlets in this region suggests that there are several chemically distinct metallocene complexes in solution. The presence of free DMA is observed at 20 minutes (the methyl groups of free DMA appear at 40 ppm).
The bulk imposed by the Cp* ligands prevents coordination of the DMA and the naked cation, [Cp* 2 HfMe][B(pfp) 4 ], is thermally unstable and quickly decomposes by loss of methane to give various metallated products. The ionic decomposition products (or at least some of them) are active olefin polymerization catalysts. The structure and thermal stability of Cp 2 ZrMe + catalysts derived from [DMAH][B(pfp) 4 ] and [Bu 3 NH][B(pfp) 4 ] were compared with the analogous hafnium systems discussed earlier.
The 13 C NMR spectra of the reaction of Cp 2 ZrMe 2 with one equivalent of [DMAH][B(pfp) 4 ] collected at t=10 minutes and t=2.5 hours are shown in FIGS. 11 and 12. After 10 minutes signals due to [Cp 2 ZrMe(DMA)][B(pfp) 4 ] were observed along with a new complex having two Cp-signals of equal intensity and high field signals at 62 ppm and 58 ppm. After 2.5 hours (12) all of the original methyl cation, [Cp 2 ZrMe(DMA)][B(pfp) 4 ], had decomposed giving a high yield of the complex giving two equal intensity Cp signals. Proton coupled 13 C NMR spectroscopy indicates that the signal at 62 ppm is a methylene group (--CH 2 --) and the signal located at 58 ppm is a methyl group (--CH 3 --). These are consistent with the structure shown below in Structure XIII. ##STR13##
The metallated complex produced by decomposition of the methyl cation (Figure XIV) is an active olefin polymerization catalyst capable of producing a polymer chain having an N-methylaniline head group.
There are differences between the properties of [Cp 2 ZrMe(DMA)][B(pfp) 4 ] and [Cp 2 HfMe(DMA)][B(pfp) 4 ]. First, the thermal stability of [Cp 2 ZrMe(DMA)][B(pfp) 4 ] is much less than the hafnium derivative. The half life of the hafnium catalyst is 18 hours compared to 1 hour for the zirconium derivative. Second, the thermal decomposition of the zirconium complex produces one well characterized cationic product while the hafnium catalyst produces several products. It should be noted that decomposition of [Cp 2 ZrMe(DMA)][B(pfp) 4 ] to give the metallated product is a possible chain transfer reaction (when Zr--Me is Zr-polymer). The fact that this reaction occurs much more rapidly correlates with the observation that the zirconium catalyst produces lower molecular weight products (i.e. less stable chains yields more rapid chain transfer). The larger decomposition, and chain transfer rates observed for zirconium catalysts relative to hafnium systems reflects the fact that the metal-carbon bond (M-Me or M-polymer) in the zirconium complexes is significantly weaker than in the corresponding hafnium systems.
The 13 C NMR spectra of the reaction of Cp 2 ZrMe 2 with [Bu 3 NH][B(pfp) 4 ] at T=20 minutes and T=20 hours are shown in FIGS. 13 and 14 respectively. The presence of free amine and many unidentified cationic products are again observed. Again, Bu 3 N is too bulky to coordinate to the metallocene center and the resulting three coordinate cation is thermally unstable.
In the preferred method of preparing the catalyst compostions of the present invention a bis(cyclopentadienyl) metal compound, said metal being selected from the Group consisting of titanium, zirconium, and hafnium, said compound containing two, independently, substituted or unsubstituted cyclopentadienyl radicals and one or two lower alkyl substituents and/or one or two hydride substituents will be combined with a trisubstituted ammonium salt of a fluorinated non-coordianting anion such as [B(C 6 F 5 ) 4 ] - or [B(C 6 F 5 ) 3 Q] - (where Q is an monoanionic non-bridging radical coordinated to boron as defined earlier). Each of the trisubstitutions of the ammonium cation will be the same or a different lower alkyl or aryl radical. By lower alkyl is meant an alkyl radical containing from one to four carbon atoms. Tri(n-butyl) ammonium tetra(pentafluorophenyl)boron and N,N-dimethylanilinium tetra(pentafluorophenyl)boron are particularly preferred activator compounds.
In a most preferred embodiment of the present invention, bis(cyclopentadienyl)zirconium dimethyl or bis(cyclopentadienyl)hafnium dimethyl will be reacted with N,N-dimethylanilinium tetra(pentafluorophenyl)boron to produce the most preferred catalyst of the present invention. The two components will be combined at a temperature within the range from about 0° C. to about 100° C. The components will be combined, preferably, in an aromatic hydrocarbon solvent, most preferably toluene. Nominal holding times within the range from about 10 seconds to about 60 minutes will be sufficient to produce both the preferred and most preferred catalyst of this invention.
In some cases, the stable catalyst formed by the method of this invention may be separated from the solvent and stored for subsequent use. Less stable catalyst, however, will, generally, be retained in solution until
ultimately used in the polymerization of olefins, diolefins and/or acetylenically unsaturated monomers. Alternatively, any of the catalysts prepared by the method of this invention may be retained in solution for subsequent use or used directly after preparation as a polymerization catalyst. Moreover, and as indicated supra, the catalyst may be prepared in situ during a polymerization reaction by passing the separate components into the polymerization vessel where the components will contact and react to produce the improved catalyst of this invention.
In a preferred embodiment, the catalyst, immediately after formation, will then be used to polymerize a lower α-olefin particularly ethylene or propylene, most preferably ethylene, at a temperature within the range from about 0° C. to about 100° C. and at a pressure within the range from about 15 to about 500 psig. In a most preferred embodiment of the present invention, the most preferred catalyst will be used either to homopolymerize ethylene or to copolymerize ethylene with a lower α-olefin having from 3 to 6 carbon atoms, thereby yielding a plastic or an elastomeric copolymer. In both the preferred and most preferred embodiments, the monomers will be maintained at polymerization conditions for a nominal holding time within the range from about 1 to about 60 minutes and the catalyst will be used at a concentration within the range from about 10 -5 to about 10 -1 moles per liter of solvent.
Having thus broadly described the present invention and a preferred and most preferred embodiment thereof, it is believed that the same will become even more apparent by reference to the following examples. It will be appreciated, however, that the examples are presented solely for purposes of illustration and should not be construed as limiting the invention. All of the examples were completed either under an argon blanket by standard Schlenk techniques or under a helium blanket in a Vacuum Atmospheres HE43-2 drybox. The solvents used in the experiments were rigorously dried under nitrogen by standard techniques. The boron and metallocene reagents used in the examples were either purchased or prepared following published techniques. The zwitterionic complexes (Examples 1, 4, 10 and 22) were characterized by solid state 13 C NMR spectroscopy and solution 1 H NMR spectroscopy. The tetra(p-ethylphenyl)boron zwitterionic derivative isolated in Example 10 was further characterized by single crystal x-ray crystallography.
EXAMPLE 1
In this example, a stable, isolable polymerization catalyst was prepared by combining 0.65 g of tri(n-butyl)ammonium tetra(phenyl)boron with 0.50 g of bis(pentamethylcyclopentadienyl)zirconium dimethyl. The combination was accomplished by first suspending the tri(n-butyl)ammonium tetra(phenyl)boron in 50 ml of toluene and then adding the bis(pentamethylcyclopentadienyl)zirconium dimethyl. The combination was accomplished at room temperature and contacting between the two compounds was continued for 1 hour. After 1 hour, an insoluble orange precipitate separated from solution leaving a clear mother liquor. The orange precipitate was isolated by filtration, washed three times with 20 ml of pentane and dried in vacuo. 0.75 g of the orange precipitate was recovered. A portion of this product was analyzed and it was found to contain a single organometallic compound having the following general formula: ##STR14## wherein Me is a methyl radical
EXAMPLE 2
In this example, ethylene was polymerized by adding 0.05 g of the orange precipitate recovered in Example 1 to 20 ml of toluene at room temperature in a 100 ml side armed flask and then adding excess ethylene at atmospheric pressure while maintaining vigorous agitation. An immediate exotherm was detected and the formation of polyethylene observed as the addition of ethylene continued.
EXAMPLE 3
In this example, ethylene was polymerized by first suspending 0.05 g of the orange precipitate prepared in Example 1 to 20 ml of chlorobenzene in a 100 ml side armed flask and then adding excess ethylene at atmospheric pressure while maintaining agitation. An immediate exotherm was detected and the formation of polyethylene was observed as the addition of ethylene continued.
EXAMPLE 4
In this example, an active, isolable olefin polymerization catalyst was prepared by first suspending 0.75 g of tri(n-butyl)ammonium tetra(p-tolyl)boron in 50 ml of toluene and then adding 0.52 g of bis(pentamethylcyclopentadienyl)zirconium dimethyl. The mixture was stirred at room temperature for 1 hour. After 1 hour, an insoluble orange precipitate separated from solution. The orange precipitate was isolated by filtration, washed three times with 20 ml of pentane and dried in vacuo. 0.55 g of the orange precipitate were recovered. The orange precipitate was analyzed and found to contain an organometallic compound having the following structure: ##STR15## wherein Me is a methyl radical.
EXAMPLE 5
In this example, ethylene was polymerized at atmospheric pressure by passing ethylene into a 20 ml sample of crude reaction mixture from Example 4 in a 100 ml side armed flask. The ethylene was rapidly polymerized.
EXAMPLE 6
In this example, ethylene was polymerized at 40 psig by dissolving 0.02 g of the orange precipitate produced in Example 4 in 100 ml of toluene in a Fisher-Porter glass pressure vessel, heating the solution to 80C. and then passing ethylene into said solution at 40 psig for 20 minutes. 2.2 g of polyethylene were obtained and the average molecular weight of the polymer was 57,000. The polymer had a polydispersity of 2.5.
EXAMPLE 7
In this example, ethylene and acetylene were copolymerized by dissolving 0.05 g of the orange precipitate from Example 4 in toluene and then adding 2 ml of purified acetylene at atmospheric pressure in an NMR Lube. An immediate color change from orange to yellow was noted. After five minutes, 5 ml of ethylene at atmospheric pressure were added to this mixture and an immediate exotherm was observed as was polymer formation.
EXAMPLE 8
In this example, an active isolable olefin polymerization catalyst was produced by first suspending 0.56 g of tri(n-butyl)ammonium tetra(o-tolyl)boron in 50 mil of toluene and then adding 0.25 g of bis(cyclopentadienyl)zirconium dimethyl. The mixture was stirred at room temperature for 1 hour. After 1 hour an insoluble yellow precipitate separated from an orange solution. The yellow precipitate was isolated by filtration, washed three times with 20 ml of pentane and dried in vacuo. 0.26 g of the yellow precipitate were recovered.
EXAMPLE 9
In this example, excess ethylene was added at atmospheric pressure to a portion of the orange mother liquor from Example 8 in a 100 ml side armed flask and polyethylene formed. Ethylene was also contacted with a portion of the yellow precipitate, which precipitate was suspended in toluene in a 50 ml side armed flask and again polyethylene was formed.
EXAMPLE 10
In this example, an active, isolable olefin polymerization catalyst was produced by first suspending 1.20 g of tri(n-butyl)ammonium tetra(p-ethylphenyl) boron in 50 ml of toluene and then adding 0.76 g of bis(pentamethylcyclopentadienyl)zirconium dimethyl. The mixture was stirred at room temperature for 1 hour. After 1 hour, the reaction mixture was evaporated to dryness. The crude orange solid, which was produced, was recrystallized from hot toluene to give 1.0 g of orange-red crystals. A portion of this product was analyzed and confirmed to be an organometallic compound having the following structure: ##STR16## wherein Me is a methyl radical.
EXAMPLE 11
In this example, ethylene was polymerized by dissolving 0.10 g of the orange-red crystals from Example 10 in toluene and then placing the solution in a steel autoclave under nitrogen pressure. Ethylene at 100 psig was then introduced into the autoclave and the autoclave heated to 80C. with agitation. After 10 minutes, the reactor was vented to atmospheric pressure and opened. The yield of linear polyethylene was 27 g having a weight average molecular weight of about 52,000.
EXAMPLE 12
In this example, an active, isolable olefin polymerization catalyst was prepared by first suspending 0.78 g of tri(n-butyl)ammonium tetra(m,m-dimethylphenyl) boron in 50 ml of toluene and then adding 0.50 g of bis(pentamethylyclopentadienyl)zirconium dimethyl. The mixture was stirred at room temperature for 1 hour. After 1 hour, the reaction mixture was evaporated to dryness. The resulting crude red-brown solid was washed with 30 ml of pentane and dried in vacuo to yield 0.56 g of a toluene soluble brown solid. Both the brown solid and the crude reaction mixture were dissolved in 40 ml of toluene in a 100 ml side armed flask and were observed to polymerize ethylene at atmospheric pressure.
EXAMPLE 13
In this example, two active, isolable olefin polymerization catalysts were prepared by first dissolving 0.78 g of tri(n-butyl)ammonium tetra(o,p-dimethylphenyl)boron in 30 ml of toluene and 15 ml of pentane. The solution was then cooled to -30C. and 0.50 g of bis(pentamethylcyclopentadienyl)zirconium dimethyl were added. The mixture was warmed to room temperature with agitation and held for 4 hours. A yellow precipitate was separated from a purple reaction mixture by filtration. The yellow precipitate was dried in-vacuo to give 0.62 g of product. After separation of the yellow precipitate, the purple mother liquor was evaporated to dryness to give 0.32 g of a purple glassy solid. The yellow and purple products polymerized ethylene in deutero-toluene in NMR tubes.
EXAMPLE 14
In this example, an olefin polymerization catalyst was prepared by combining 0.06 g of bis(1,3-bis(trimethylsilyl)cyclopentadienyl)zirconium dimethyl, 0.05 g of N,N-diethylanilinium tetra(phenyl)boron and 1 ml of deuterobenzene in an NMR tube and allowing the components to react. The NMR spectrum showed complete loss of starting materials after 20 minutes at room temperature. The reaction mixture was then divided into two portions, diluted with 20 ml toluene, and placed in 50 ml side armed flasks. Ethylene was added to one portion and propylene to the other. Rapid polymerization was observed in both cases.
EXAMPLE 15
In this example, an active olefin polymerization catalyst was prepared by first suspending 0.87 g of tri(n-butyl)ammonium tetra(p-tolyl)boron in 50 ml of toluene and then adding 0.50 g of (pentamethylcyclopentadienyl)(cyclopentadienyl)zirconium dimethyl. The reaction was stirred at room temperature for 18 hours to give a blue-green homogenous solution. The reaction mixture was dried in-vacuo, washed with 30 ml of pentane, and then redissolved in 100 ml of toluene. The resulting blue-green solution was filtered into a glass pressure vessel and stirred under 1.5 atmospheres of ethylene. An immediate exotherm and polymer formation was observed upon exposure of ethylene. The yield of polyethylene was 4.5 g after 15 minutes.
EXAMPLE 16
In this example, an olefin polymerization catalyst was prepared by first suspending 0.1 g of tri(n-butyl)ammonium tetra(p-ethylphenyl)boron in 5 ml of d 6 -benzene and then adding 0.05 g of (pentamethylcyclopentadienyl) (cyclopentadienyl)zirconium dimethyl. The reaction was complete after 30 minutes. The green solution was then dried in-vacuo to give a green glassy solid. The crude green product was extracted with 20 ml of toluene. In separate experiments, the toluene extract was exposed to ethylene, to propylene and to a mixture of ethylene and propylene. In each case significant polymerization activity was observed.
EXAMPLE 17
In this example, an active olefin polymerization catalyst was prepared by first suspending 0.22 g of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron in 50 ml of toluene and then adding 0.10 g of bis(pentamethylcyclopentadienyl) zirconium dimethyl. The reaction vessel was capped with a rubber septum and stirred at room temperature. After 10 minutes the reaction mixture (now yellow and homogeneous) was pressurized with 1.5 atmospheres of ethylene and stirred vigorously. Rapid polymerization of ethylene was observed causing a significant increase in the reaction temperature (from room temperature to at least 80C.) during the first 5 minutes of polymerization. After 15 minutes, the reaction vessel was vented and methanol was added to kill the still active catalyst. The yield of linear polyethylene was 3.7 g.
EXAMPLE 18
In this example, an active olefin polymerization catalyst was prepared by suspending 0.34 g of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron in 50 ml of toluene and then adding 0.13 g of (pentamethylcyclopentadienyl)(cyclopentadienyl)zirconium dimethyl. The reaction vessel was capped with a rubber septum and stirred at room temperature. After 10 minutes the reaction mixture (a yellow solution above an insoluble orange oil) was pressurized with 1.5 atmospheres of ethylene and stirred vigorously. Rapid polymerization of ethylene was observed causing a significant increase in the reaction temperature (from room temperature to at least 80C.) during the first minutes of polymerization. After 10 minutes, the reaction vessel was vented and methanol was added to kill the still active catalyst. The yield of linear polyethylene was 3.7 g.
EXAMPLE 19
In this example, an active olefin polymerization catalyst was prepared by combining 0.18 g of tri(n-butyl) ammonium tetra(pentafluorophenyl)boron in 50 ml of toluene and then adding 0.12 g of bis [1,3-bis(trimethylsilyl)cyclopentadienyl]zirconium dimethyl. The reaction vessel was capped with a rubber septum and stirred at room temperature. After 10 minutes the reaction mixture (a yellow solution above an insoluble yellow oil) was pressurized with 1.5 atmospheres of ethylene and stirred vigorously. Rapid polymerization of ethylene was observed causing a significant increase in the reaction temperature (from room temperature to at least 80C.) during the first minutes of polymerization. After 10 minutes the reaction vessel was vented and methanol was added to kill the still active catalyst. The yield of linear polyethylene was 2.1 g.
EXAMPLE 20
In this example, an active olefin polymerization catalyst was prepared by suspending 0.34 g of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron in 50 ml of toluene and then adding 0.10 g of bis(cyclopentadienyl)zirconium dimethyl. The reaction vessel was capped with a rubber septum and stirred at room temperature. After 10 minutes the reaction mixture (a yellow solution above an insoluble orange oil) was pressurized with 1.5 atmospheres of ethylene and stirred vigorously. Rapid polymerization of ethylene was observed causing a significant increase in the reaction temperature (from room temperature to at least 80C.) during the first minutes of polymerization. After 10 minutes the reaction vessel was vented and methanol was added to deactivate the still active catalyst. The yield of linear polyethylene was 3.7 g.
EXAMPLE 21
In this example, an active olefin polymerization catalyst was prepared by combining 0.12 g of tri(n-butyl)ammonion tetra(pentafluorophenyl)boron and 0.04 g of bis(cyclopentadienyl)zirconium dimethyl in 100 ml of toluene in a 250 ml flask. The flask was capped with a rubber septum and stirred at 60C. for 3 minutes. Ethylene 1.5 atmospheres and 3 mi of 1-hexene were then added to the flask. After 20 minutes, the flask was vented and methanol was added to deactivate the still active catalyst. The white polymeric product was collected by filtration and dried in vacuo to yield 8.0 g of a hexane-ethylene copolymer. The melting point of the copolymer was 125C.
EXAMPLE 22
In this example, an active, isolable olefin polymerization catalyst was prepared by first suspending 1.30 g of tri(n-butyl)ammonium tetra(p-tolyl) boron in 50 of toluene and then adding 1.00 g of bis(ethyltetramethylcyclopentadienyl)zirconium dimethyl. The mixture was stirred at room temperature for 1 hour. After 1 hour, an insoluble orange precipitate separated from solution. The orange precipitate was isolated by filtration, washed three times with 20 ml of pentane and dried in vacuo. 0.55 g of the orange precipitate were recovered. The orange precipitate was analyzed and found to contain an organometallic compound having the following structure: ##STR17## wherein Et is an ethyl radical and Me is a methyl radical.
EXAMPLE 23
In this example, 0.05 g of the orange precipitate produced in Example 22 was dissolved in 2 ml of deuterotoluene and placed in a 5 mm NMR tube and capped with a rubber septum. Ethylene (2 ml at 1 atm) was added via syringe and immediately polymerized.
EXAMPLE 24
In this example, ethylene and 1-butene were copolymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen and containing 400 ml of dry oxygen-free hexane, 40 ml of a toluene solution containing 4 mg of bis(cyclopentadienyl)zirconium dimethyl and 12 mg of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron. 1-butene (200 ml) was added to the autoclave, which was further pressurized with 65 psig of ethylene. The autoclave was stirred and heated for 7 minutes at 60C. The reactor was vented and cooled and the contents dried. The yield of copolymer isolated was 9.2 g. The weight-average molecular weight of the polymer was 108,000 and the molecular weight distribution was 1.97. A compositional distribution analysis indicated a breadth index of 88%.
EXAMPLE 25
In this example, ethylene and 1-butene were copolymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen and containing 400 ml of dry, oxygen-free hexane, 40 ml of a toluene solution containing 4 mg of bis(cyclopentadienyl)zirconium dimethyl and 12 mg of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron. 1-butene (200 ml) was added to the autoclave, which was further pressurized with 65 psig of ethylene. The autoclave was stirred and heated at 50C. for 10 minutes. The autoclave was vented and cooled and the contents dried. The yield of copolymer isolated was 7.1 g. The weight-average molecular weight of the polymer was 92,000 with a molecular weight distribution of 1.88. Analysis by 13 C NMR spectroscopy indicated a reactivity ratio (r 1 r 2 ) of 0.145.
EXAMPLE 26
In this example, ethylene and 1-butene were copolymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen and containing 400 ml of dry, oxygen-free hexane, 25 ml of a toluene solution containing 9 mg of bis[(t-butyl)cyclopentadienylzirconium dimethyl and 2.9 mg of N,N-dimethylanilinium tetra(pentafluorophenyl)boron. 1-butene (100 ml) was added to the autoclave, which was further pressurized with 65 psig of ethylene. The autoclave was stirred and heated at 50C. for 1 hour. The autoclave was vented and cooled and the contents dried. The yield of copolymer isolated was 27.2 g. The weight-average molecular weight of the polymer was 23,000 with a molecular weight distribution of 1.8. Analysis of the composition distribution indicated a median comonomer content of 6.3 mole % and a breadth index of 81%.
EXAMPLE 27
In this example, a stirred 100 ml steel autoclave reaction vessel which was equipped to perform Ziegler-Natta polymerization reactions at pressures up to 2500 bar and temperatures up to 300C. was used. The temperature of the cleaned reactor containing ethylene at low pressure was equilibrated at the desired reaction temperature of 160C. The catalyst solution was prepared by dissolving 259 mg of a zwitterionic catalyst (prepared from bis(ethyltetramethylcyclopentadienyl)zirconium dimethyl and tri(n-butyl)ammonium tetra(p-ethylphenyl) boron in 10.0 ml of distilled toluene under nitrogen. A 0.4 ml portion of this catalyst solution was transferred by low-pressure nitrogen into a constant-volume injection tube, which was held at 25C. Ethylene was pressured into the autoclave at a total pressure of 1500 bar. The reactor contents were stirred at 1000 rpm for 1 minute at which time the catalyst solution was rapidly injected into the stirring reactor with excess pressure. The temperature and pressure changes were recorded continuously for 120 seconds at which time the contents were rapidly vented, yielding the polymer. The reactor was washed with xylene to collect any polymer remaining inside and all polymer was dried in vacuo. The yield of polyethylene isolated was 0.56 g. This polymer had a weight-average molecular weight of 21,900, a molecular weight distribution of 10.6 and a density of 0.965 g/ml.
EXAMPLE 28
In this example, ethylene was polymerized by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously purged with nitrogen and containing 400 ml of dry, oxygen-free hexane, first a solution of 15 mg of bis(cyclopentadienyl)hafnium dimethyl in 30 ml of toluene, then, after 5 minutes, a toluene solution (50 ml) containing 12 mg of bis(cyclopentadienyl)hafnium dimethyl and 30 mg of tri(n-butyl)ammonium tetrakis(perfluorophenyl)boron. The autoclave was pressured with 90 psig of ethylene and stirred at 60C. After 1 hour, the autoclave was vented and opened. The yield of linear polyethylene isolated was 73.8 g. This material had a weight-average molecular weight of 1,100,000 and a molecular weight distribution of 1.78.
EXAMPLE 29
In this example, ethylene and propylene were copolymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainleess-steel autoclave previously flushed with nitrogen and containing 400 ml of dry, oxygen-free hexane, first a solution of 15 mg bis(cyclopentadienyl)hafnium dimethyl in 25 ml of toluene, stirring for 5 minutes, then 50 ml of a toluene solution containing 17 mg bis(cyclopentadienyl)hafnium dimethyl and 42 mg of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron. Propylene (200 ml) was added to the autoclave, which was further pressured with an additional 50 psig of ethylene. The autoclave was stirred at 60C. for 15 minutes. The reactor was vented and opened and the residual hexane in the contents evaporated under a stream of air. The yield of copolymer isolated was 61.0 g. This copolymer, which was 35.1 wt % ethylene, had a weight-average molecular weight of 103,000 and a molecular weight distribution of 2.3. Analysis by 13 C NMR spectroscopy indicated a statistically random copolymer.
EXAMPLE 30
In this example, ethylene and propylene were copolymerized in bulk propylene by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave preeviously flushed with nitrogen 50 ml of a toluene solution containing 36 mg of bis(cyclopentadienyl)hafnium dimethyl and 11 mg of N,N-dimethylanilinium tetra(pentafluorophenyl)boron. Propylene (400 ml) was added to the autoclave, which was further pressurized with 120 psig of ethylene. After stirring for 15 minutes at 50C., the reactor was vented and opened and the contents dried under a stream of air. The yield of copolymer isolated was 52.6 g. The copolymer, which was 38.1 wt % ethylene, had a weight-average molecular weight of 603,000 and a molecular weight distribution of 1.93.
EXAMPLE 31
In this example, ethylene and 1-butene were copolymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen and containing 400 ml of dry, oxygen-free hexane, first a 30 mi of a toluene solution containing 15 mg of bis(cyclopentadienyl hafnium dimethyl, then after stirring for 5 minutes, 30 ml of a toluene solution containing 12 mg of bis(cyclopentadienyl)hafnium dimethyl and 30 mg of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron. 1-butene (50 ml) was added to the autoclave, which was further pressurized with 65 psig of ethylene. The autoclave was stirred and heated to 50C. for 1 hour. The reactor was vented and opened and the contents dried in a vacuum oven. The yield of copolymer isolated was 78.7 g. This copolymer, which was 62.6 wt % ethylene, had a weight-average molecular weight of 105,000 and a molecular weight distribution of 4.94. Analysis by 13 C NMR spectroscopy indicated a reactivity ratio (r 1 r 2 ) of 0.153.
EXAMPLE 32
In this example, ethylene, propylene, and 1-butene were copolymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainless-steel reactor, previously flushed with nitrogen and containing 400 ml of dry, oxygen-free hexane, 50 ml of a toluene solution containing 19 mg of bis(cyclopentadienyl)hafnium dimethyl and 15 mg of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron. 1-butene (50 ml) and propylene (25 ml) were added to the autoclave, which was further pressurized with 60 psig of ethylene. The autoclave was stirred at 50C. for 45 minutes, then cooled and vented. The contents were dried under a stream of air. The yield of isolated terpolymer was 17.9 g. The weight-average molecular weight of the polymer was 188,000 and the molecular weight distribution was 1.89. Analysis by 13 C NMR spectroscopy indicated that the polymer contained 62.9 mole % ethylene, 25.8 mole % propylene, and 11.3 mole % butene.
EXAMPLE 33
In this example, ethylene, propylene, and 1,4-hexadiene were copolymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen and containing 400 ml of dry, oxygen-free hexane, first 100 ml of freshly-distilled 1,4-hexadiene, then 50 ml of a catalyst solution containing 72 mg of bis(cyclopentadienyl)hafnium dimethyl and 16 mg N,N-dimethylanilinium tetra(perfluorophenyl)boron. Propylene (50 ml) was added to the autoclave, which was further pressurized with 90 psig of ethylene. The autoclave was stirred at 50C. for 10 minutes, then cooled and vented. The contents were dried under a stream of air. The yield of isolated terpolymer was 30.7 g. The weight-average molecular weight of the polymer was 191,000 and the molecular weight distribution was 1.61. Analysis by 13 C NMR spectroscopy indicated that the polymer contained 70.5 mole % ethylene, 24.8 mole % propylene, and 4.7 mole % 1,4-hexadiene.
EXAMPLE 34
In this example, ethylene and 1-hexene were copolymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen and containing 400 ml of dry, oxygen-free hexane, first 30 ml of toluene solution containing 15 mg of bis(cyclopentadienyl)hafnium dimethyl, then, after 5 minutes, 100 ml of alumina-filtered and degassed 1-hexene and then 50 ml of a toluene solution containing 12 mg of bis(cyclopentadienyl)hafnium dimethyl and 30 mg of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron. The autoclave was pressurized with 65 psig of ethylene, stirred and heated at 50C. for 1 hour, then cooled and vented. The contents were dried in a vacuum oven. The yield of isolated copolymer was 54.7 g. The copolymer, which was 46 wt % ethylene, had a weight-average molecular weight of 138,000 and a molecular weight distribution of 3.08. Analysis by 13 C NMR spectroscopy indicated a reactivity ratio (r 1 r 2 ) Of 0.262.
EXAMPLE 35
In this example, propylene was polymerized in a hexane diluent by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen and containing 200 ml of dry, oxygen-free hexane, 50 ml of a toluene solution containing 72 mg of bis(cyclopentadienyl)hafnium dimethyl and 22 mg of N,N-dimethylanilinium tetraks(pentafluorophenyl)boron. Propylene (200 ml) was added and the autoclave was stirred at 40C. for 65 minutes. The autoclave was cooled and vented and the contents dried in a vacuum oven. The yield of atactic polypropylene was 37.7 g. The weight-average molecular weight of this polymer was 92,000 and the molecular weight distribution was 1.54.
EXAMPLE 36
In this experiment, propylene was polymerized in bulk propylene by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen, 50 ml of a toluene solution containing 77 mg of bis(cyclopentadienyl)hafnium dimethyl and 22 mg of N,N-dimethylanilinium tetra(pentafluorophenyl)boron. Propylene (400 ml) was added and the autoclave stirred at 40C. for 90 minutes. The autoclave was cooled and vented and the contents dried in a vacuum oven. The yield of atactic polypropylene isolated was 58.7 g. The weight-average molecular weight of this polymer was 191,000 and the molecular weight distribution was 1.60.
EXAMPLE 37
In this example, propylene was polymerized in bulk propylene by washing 72 mg of bis(cyclopentadienyl)hafnium dimethyl and 22 mg of N,N-dimethylanilinium tetra(pentafluorophenyl)boron into a 1 L stainless-steel autoclave, previously flushed with nitrogen, with 500 mL of propylene. The autoclave was stirred at 40C. for 90 minutes and at 50C. for another 30 minutes, then cooled and vented. 2.3 g of atactic polypropylene were isolated.
EXAMPLE 38
In this example, ethylene was polymerized by reacting 55 mg of bis(trimethylsilylcyclopentadienyl)hafnium dimethyl with 80 mg of N,N-dimethylanilinium tetra(pentafluorophenyl)boron in 5 ml of toluene in a serum-capped vial. On passing ethylene through the solution for 15 seconds, polymer formed as the mixture grew hot. The vial was opened and the contents diluted with acetone, filtered, washed, and dried. The yield of polyethylene was 0.26 g.
EXAMPLE 39
In this example, propylene was polymerized in bulk propylene by adding under a nitrogen atmosphere to a 1 L stainless-steel autoclave, previously flushed with nitrogen, 25 ml of a toluene solution containing 10 mg of rac-dimethylsilylbis(indenyl)hafnium dimethyl and 5 mg of N,N-dimethylanilinium tetrakis (pentafluorophenyl) boron. Propylene (500 ml) was added and the autoclave stirred at 40C. for 4.5 hours. The autoclave was cooled and vented and the contents dried in a vacuum oven. The yield of isotactic polypropylene isolated was 78.5 g. The weight-average molecular weight of this polymer was 555,000 and the molecular weight distribution was 1.86. The polymer had a melting point of 139C. Analysis by 13 C NMR spectroscopy indicated that the polymer was about 95% isotactic.
EXAMPLE 40
In this example, an active ethylene polymerization catalyst was prepared by suspending 40 mg of N,N-dimethylanilinium tetrakis (pentafluorophenyl)boron and 17 mg of 1-bis(cyclopentadienyl)zircona-3-dimethylsilacyclobutane in 10 ml of toluene in a septum-capped round bottomed flask. Passage of ethylene through the solution for 30 seconds caused the solution to become hot as polymer precipitated. The flask was opened and the contents diluted with acetone. The polymer was filtered off, washed with acetone, and dried in vacuo. The yield of polymer isolated was 0.15 g.
EXAMPLE 41
In this example, an active ethylene polymerization catalyst was prepared by suspending 36 mg of 1-bis(cyclopentaienyl)titana-3-dimethyl-silacyclobutadiene and 80 mg of N,N-dimethylanilinium tetrakis(pentafluorophenyl)boron in 20 ml of toluene in a serum-capped round-bottomed flask. The solution darkened when ethylene was passed through it. After 5 minutes, the flask was opened and the contents diluted with ethanol. The polymer was filtered off, washed with ethanol, and dried. The yield of polyethylene isolated was 0.51 g.
EXAMPLE 42
In this example, an active ethylene polymerization catalyst was prepared by suspending 29 mg of (pentamethylcyclopentadienyl)(tetramethylethylene)cyclopentadienyl)zirconium phenyl and 43 mg of tri(n-butyl)ammonium tetrakis (pentafluorophenyl)boron in 25 ml of toluene in a serum-capped round bottomed flask. On passing ethylene through the solution, polymer formed almost instantly. After 5 minutes, the flask was opened and the contents diluted with ethanol. The polymer was filtered off, washed with acetone, and dried. The yield of polyethylene isolated was 0.49 g.
EXAMPLE 43
In this example, an active ethylene polymerization catalyst was prepared by suspending 34 mg of bis(cyclopentadienyl)zirconium (2,3-dimethyl-1,3-butadiene) and 85 mg of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron in 50 ml of toluene in a serum-capped bottle. On introducing ethylene, the solution grew warm instantly as polymer precipitated. After 5 minutes the bottle was opened and the contents diluted with ethanol. The polymer formed was filtered off, washed with ethanol, and dried. The yield of polymer isolated was 1.06 g.
EXAMPLE 44
In this example, ethylene was polymerized by reacting 20 mg of 1-bis(cyclopentadienyl)hafna-3-dimethylsilacyclobutane and 39 mg of N,N-dimethylanilinium tetra(pentafluorophenyl)boron in 20 ml of toluene in a serum-capped round-bottomed flask. On passing ethylene through the solution, polymer precipitated as the solution grew warm. After 1 minute, the flask was opened and the contents diluted with ethanol. The polymer was filtered off, washed with ethanol, and dried. The yield of polyethylene isolated was 0.263 g.
EXAMPLE 45
In this example, ethylene was polymerized by reacting 21 mg of bis(cyclopentadienyl)hafnium (2,3-dimethyl-1,3-butadiene) and 41 mg of tri(n-butyl)ammonium tetra(pentafluorophenyl)boron in 50 ml of toluene in a serum capped bottle. On passing ethylene through the solution, polymer precipitated within seconds. After 10 minutes, the bottle was opened and the contents diluted with ethanol. The solid polymer was filtered off, washed with acetone, and dried. The yield of polyethylene isolated was 0.93 g.
EXAMPLE 46
In this example, ethylene was polymerized by reacting 53 mg of (pentamethylcyclopentadienyl)(tetramethylcyclopentadienylmethylene)hafnium benzyl and 75 mg of N,N-dimethylanilinium tetrakis(pentafluorophenyl)boron in 50 ml of toluene in a serum-capped bottle. Ethylene was passed through the solution for 10 minutes. The bottle was opened and the contents diluted with ethanol. The polymer was filtered off, washed with acetone, and dried. The yield of polyethylene isolated was 0.65 g.
While the present invention has been described and illustrated by reference to particular embodiments thereof, it will be appreciated by those of ordinary skill in the art that the same lends itself to variations not necessarily illustrated herein. For this reason, then, reference should be made solely to the appended claims for purposes of determining the true scope of the present invention. | Ionic catalyst compositions can be prepared by combining two components. The first component is a bis(cyclopentadienyl) Group IV-B metal complex containing at least one ligand which will combine irreversibly with the second component or at least a portion thereof such as a cation portion thereof. The second component comprises a cation which will irrevesibly react with at least one ligand on the Group IV-B metal complex and a non-coordinating anion. The combination of the two components produces an ionic catalyst composition comprising a cationic bis(cyclopentadienyl) Group IV-B metal complex which has a formal coordination number of 3 and a 4+ valence charge and the aforementioned non-coordinating anion. The anion is (i) labile and can be displaced by an olefin, diolefin or acetylenically unsaturated monomer; (ii) has a molecular diameter about or greater than 4 angstroms; (iii) forms stable salts with reducible Lewis acids and protonated Lewis bases; (iv) has a negative charge delocalized over the framework on the anion or within the core thereof; (v) is not a reducing or oxidizing agent; and (vi) is a relatively poor nucleophile. These ionic catalyst compositions can be used to polymerize α-olefins, diolefins and/or acetylenically unsaturated monomers, either alone or in combination, to polymers and copolymers. | 8 |
BACKGROUND OF THE INVENTION
This invention is related to snow plows; and more particulary, to pneumatic, plows for small vehicles.
Over time, a number of devices have been developed to plow snow from roads, driveways, and parking lots. These designs, typically large, heavy and cumbersome are designed for big trucks and pick-up trucks. Examples of this type of plow can be found in U.S. Pat. Nos. 3,483,641, 4,439,939, 2,694,267, 4,304,056, 2,867,921, and 3,214,138.
In the 1970's a number of factors produced a smaller size vehicle--the sub-compact cars and trucks. The size of these vehicles was such that existing plows couldn't be used with them, although for light plowing jobs i.e. driveways, sidewalks or small confined areas, these vehicles are ideal.
The problem of reducing the large plows to fit the smaller plows is two fold: First, the vehicles lack the heavy suspensions and extra weight of their larger counterparts; they also lack adequate room for extra batteries, larger alternators and the hydraulic systems commonly found in the case of larger plows. Second, the plows themselves cannot simply be shrunk down to fit these smaller cars. In effect, the plows have to be redesigned to do the job on a simpler level.
It is an object of this invention to produce a lightweight snow plow for use with small vehicles. A second object of the invention is to develop a new mounting system to provide proper distribution of the many forces on a snow plow blade that utilizes a new mounting system consisting primarily of a yoke arrangement that is connected to a swing arm assembly that makes a single point connection to the vehicle.
Another object of the present invention is the use of an upstop device that prevents the plow blade from rising too high, thereby obscuring the headlights of the vehicle. As yet another object of the invention is the provision of an uplock device that is used to secure the blade in a raised position and to keep it in that position when not in use. The uplock will prevent the blade from dropping to the ground when the vehicle is being driven, which could pose to be a serious hazard to the vehicles and other vehicle on the road.
Finally, another object of the invention is the provision of a simple means to angle the blade when necessary.
BRIEF DESCRIPTION OF THE INVENTION
The invention consists of a removable snow plow that is used on small vehicles. The plow can be used on either a light pick-up truck or a compact car. Unlike other vehicular mounted plows, this plow is designed to be easily removed and installed by one person. There is only one mechanical, and one electrical connection to the vehicle. The plow has all of the operating parts mounted to it so there is no need to install a separate compressor and air tank, or hydraulic system within the vehicle.
The device comprises an aluminum plow blade that is curved to enable it to plow snow more efficiently. Aluminum plates are welded to the rear of the outer edges and along the rear bottom edge of the blade to stiffen it sufficiently for use. the blade also has two steel mounting brackets that are positioned to accept a mounting yoke.
A mounting yoke is fastened to the blade with a pin and bushing arrangement. The mounting yoke has provisions for two pairs of springs which fasten to the blade to act as shock absorbers. The mounting yoke also has mounting holes for a blade angle adjusting chain, which in turn is fastened to the swing arms.
The swing arms consist of an angle iron and two pieces of square tubing, that extend purpendicularly outward from the angle iron. A stiffener bracket is mounted at the rear of the tubing to maintain spacing. This bracket is also used to secure the blade angle adjusting chain, which is attached to the blade mounting yoke. The chain is used to position the blade for angled plowing. The blade is turned to the proper position and then the chain is simply dropped into a slot provided on top of the stiffener bracket to hold the desired angle.
A pedestal consisting of two pieces of square tubing, mounted at right angles is also included. The vertical tube is sealed at the ends, forming a tank to store the compressed air under pressure. The second tube extends horizontally from the tank and acts as the plow mounting arm. This arm is inserted into the hitch recepticle mounted on the vehicle.
A small, electrically driven, compressor is mounted to the tank. A solenoid valve is also mounted on the tank. The output of the tank is supplied to the air ram through the solenoid valve utilizing hoses. The air ram is connected between the air tank and the swing arm assembly. The air ram provides power for the up and down movement of the plow.
The pedestal is mounted to the swing arm assembly by a single pin which passes through the swing arms and the pedestal. This single connection point allows the swing arm assembly, which is fastened to the blade, to pivot up and down as needed. This entire assembly can be easily removed and installed on the vehicle.
The solenoid valve, compressor, and uplock solenoid are controlled by the switches mounted in the vehicle. The switch wiring terminates in a female plug assembly that is mounted near the front of the vehicle. The compressor, valve, and uplock solenoid wiring are terminated in a male plug assembly, which is fixed to the plow. Once the plow is installed on the vehicle, the operator simply plugs in the system to energize it.
A solenoid operated upstop/uplock is provided. This consists of a bracket, latch, solenoid and spring assembly. The upstop is used to prevent the blade from rising too far, thereby blocking the headlights of the vehicle. This not only provides a measure of safety, it also eliminates the need for additional sets of headlights commonly used with other snow plow designs, thereby allowing the same plow to be used on many different sized vehicles.
The uplock feature is used to secure the plow at a height safe for driving. Without the lock, it is possible, under certain conditions, for the plow to drop to the ground. This could be extremely hazardous if the vehicle is moving at a high rate of speed. With the uplock in place, however, this possibility is greatly reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the invention.
FIG. 2 is an exploded detail view of the blade yoke assembly.
FIG. 3 is a detail view of the swing arm assembly.
FIG. 4 is a detail view of the pedestal assembly.
FIG. 5 is a side view detail of the swing arm assembly.
FIG. 6 is a side view detail of the uplock bracket for manual operation.
FIG. 6a is a side view detail of the uplock bracket for automatic operation.
FIG. 7 is a schematic diagram of the electrical control wiring.
FIG. 8 is a schematic diagram of the pneumatic system of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIG. 1, the invention comprises a snow plow 1 that is designed to be mounted to the vehicle at one point. The snow plow 1 is constructed of several sub assemblies. The first is the blade 2. The blade 2 is made of lightweight metal, preferably aluminum. Plastic, PVC and other, lightweight, non-metallic materials can be used also. The blade 2 is curved to provde a proper surface for plowing. In the preferred embodiment, the height of the blade is 18 inches. This not only allows the blade to plow through substantial amounts of snow, it also does not cover the vehicle's headlamps when the blade 2 is in the up position. The blade 2 is stiffened around its perimeter with 2 vertical stiffeners 3 and 4, and a horizontal stiffener 6. The top edge 5 of the blade 2 provides additional stiffening, without additional metal. Two support braces 7 and 8 (note, 8 is hidden behind the pedestal 40 but is essentially constructed in the same manner as 7), are positioned as shown and act to receive the blade mounting yoke pins 14 and 15, thus securing the blade mounting yoke 10. This arrangement allows for the easy removal of the blade for maintenance.
Referring now to FIG. 2, the blade mounting yoke 10 is made from angle iron and tubing. The mounting bracket 11 is formed as shown. Two pieces of tubing are used to form the spring extensions 12 and 13, which are welded into place within the mounting bracket 11. Two blade mounting pins 14 and 15 are mounted on the ends of the extensions when they are welded into place. The pins 14 and 15 are inserted into brackets 16 and 17. The brackets 16 and 17 are bolted onto the support braces, 7 and 8, on the blade (see FIG. 1). The brackets 16 and 17 are bolted into place so that they can be removed to allow for blade replacement.
A center blade return stop 18 is welded to the top of the mounting bracket 11 as shown.
Two spring support brackets 19 and 20 are mounted at the rear of the spring extensions 12 and 13. Two pairs of springs 21 and 22 (note: each number represents two springs, two connecters, etc.) are mounted between the spring support brackets 19 and 20 as shown. The springs extend to the blade 2 and are fastened at points 23 and 24 with eye bolts.
Referring now to FIGS. 3, 4 and 5, the swing arm assembly 30 consists of a front angle iron 31 positioned as shown. Two square tubing pieces 32 and 33 are fastened to the angle also as shown. The tubing pieces are welded or otherwise secured by known methods in the art. A spacer bracket 34 is positioned at the rear of the tubes 32 and 33 as shown. Its function is to maintain the spacing of the tubes 32 and 33 and to act as a mount for the chain adjusting slot. The bracket 34 is welded to the tubing as shown. The control chain 29 is used to maintain the angle of the blade 2 once it has been set manually. The chain 29 is connected to holes 25 and 27 on the blade mounting yoke 11. It is then passed through the chain slot 35 on the swing arm assembly 30. The use of the chain 29 will be discussed in greater detail below.
A locking bar 36 is also provided on the swing arm assembly 30. The use of this bar will also be discussed below.
The swing arm assembly 30 is connected to the blade mounting yoke 11 by sliding the angle portion 31 into the space of the yoke 11 until hole 38 is aligned with the holes 26 and 28 on the yoke 11. Note that FIG. 5 shows a spacer pipe 37, which is fastened to the angle 31. A bolt (not shown) is then passed through the yoke at hole 26, through the angle 31 at hole 38, through the spacer 37 and finally, through hole 28 in the bottom of the yoke 11. The bolt is then fastened with a locknut.
Referring now to FIG. 4, the plow has a self contained air tank assembly or pedestal 40. The pedestal has a vertical portion 41 that is used as an air tank. The tank is built of square tubing. Both ends of the tank 41 are sealed with welded plates, thereby forming an air tight cavity. The lower portion of the pedestal 40 forms the plow mounting arm 42. The plow mounting arm 42 is used to connect the entire plow assembly to the vehicle at the frame assembly 60. The plow mounting arm 42 is also used to fasten the pedestal 40 to the swing arm assembly 30 at hole 45. The tank is connected to the swing arm assembly at point 39, using pin 43. This allows the tank to act as a pivot point for the blade when it is raised or lowered (this action is caused by the air ram discussed below). The pedestal 40 is also fitted with a handle 44, which is welded to the top of the tank portion 41. This handle 44 is used in installing and removing the blade assembly.
A standard lightweight air ram cylinder 55 is attached to the pedestal 40, as shown in FIGS. 1 and 4, at the bracket 46. The cylinder 55 is then connected to the swing arm assembly 30 at bracket 95. The cylinder 55 is then able to lift or lower the entire blade assembly, once the pedestal assembly 40 is firmly attached to the vehicle.
Another novel feature of this plow, is that the air compressor and control valve are attached to the pedestal 40. This eliminates the need for air lines running from the vehicle to the plow. It also eliminates the need to modify the vehicle with compressors and valves and hoses.
Referring now to FIG. 1, the compressor 56 is attached to the side of the pedestal 40 as shown. The location of the compressor should be chosen in view of the need to run connecting hoses 58 between the compressor 56, the control valve 57 and the air ram 55. An electricly operated solenoid valve 57 is used in the preferred embodiment to control air flow from the tank and compressor. The valve 57 is connected to the air tank at hole 48 (see FIG. 4), which taps into the tank 41. This tap must be sealed to prevent air loss. The connecting hoses 58 are run as shown in the schematic connecting diagram (FIG. 8). This is a standard routing arrangement, which utilizes standard connecting fittings as needed to make the connections. The electrical controls for the compressor 56 and the valve 57 are discussed below.
The entire blade assembly 1 is connected to the vehicle at the frame means 60. The frame 60 consists of a squared tubing "T" frame 61 as shown. The plow mounting arm 42 of the pedestal 40 is inserted into the front end of the frame assembly 60 at point 62. The blade assembly is secured to the frame assembly with a pin 63, which is inserted into both the frame 60 at point 65 and the connector portion 42 at point 64.
The frame assembly 60 is fastened to the vehicle with the straps 66 and 67. These straps bolt to either existing brackets (not shown), or to those added to the vehicle. A rear strap 68 is also used to provide additional support. This strap is attached to the vehicle with strap 69, which also bolts into place.
A novel feature of this invention is the combination upstop/uplock device. Referring to FIGS. 4, 5 and 6, the uplock/upstop device 70 consists of a clamp portion 71 which is formed from steel channel. The clamp 71 is designed to fit around the pedestal 40. The clamp is held tightly to the tank by means of a bolt 72 and nut. This bolt will compress the clamp 71 around the pedestal and hold it in a fixed position. The bolt 72 also allows the clamp to be moved up and down the tank as needed to adjust the stop height of the blade and to set the upper limit of travel. For use as an upstop, the clamp is positioned at a level that prevents the blade form rising past the level of the headlamps of the vehicle. If the blade blocked the headlamps, it could produce a hazardous driving condition. The upstop works by blocking the upward movement to the swing arm assembly 30. This occurs when the tubing pieces, 32 and 33, on the swing arm assembly contact the clamp 71. Clamp 71 simply blocks any further upward movement of the released assembly, and, therefore, the blade.
The uplock device is used to ensure the safety of the vehicle when the blade is not in use. Typically, most blades are held up by hydraulic or pneumatic pressure. If the hydraulic system failed, the blade would drop to the road bed. If this occurs when the vehicle is in motion, at highway speeds, it could cause serious damage.
Referring now to FIGS. 6 and 6a, two different uplocks are disclosed. The first is a manually operated device. To operate the uplock, the latch 73 is pivoted outward from the pedestal. The swing arm assembly 30 is then raised unti the holding bar 36 is above the latch jaw 77. The latch is then pivoted back until the latch jaw 77 is under the holding bar. The swing arm assembly 30 is then lowered until the holding bar is securely held by the latch 73.
A second uplock is also disclosed. This uplock is controlled by a solenoid. The powered uplock is activated by the uplock solenoid 75, which acts to automatically pivot the latch 73 in the same manner as that of the manual device. The uplock is also provided with a spring 76 that will set the uplock in the latch position when the power to the solenoid is removed. The weight of the plow will be applied to the jaw 77 of the latch 73, thereby preventing the plow from dropping. In order to release the latch 73 and free the plow, the compressor switch must be turned on, which will activate both the compressor and the latch solenoid 75. As long as the weight of the plow is on the latch jaw 77, the solenoid 76 will not pull up the latch 73. Once the plow switch is placed in the up position, air pressure is applied to the ram which will raise the plow. After the blade is raised approximately 1/2", the latch 73 will be released and the solenoid will pull up the latch 73 into the operating position. The device is designed to hold the latch 73 open during use of the plow. To activate the latch, both the compressor switch and the plow switch must be placed in the down (off) position simultaneously. This will release the latch 73 immediately, while the plow is dropped down over a 3 to 5 second delay as air is bled from the air ram.
Referring now to FIGS. 1 and 8, the compressor 56, the uplock solenoid 75, and solenoid valve 57 are controlled from inside the cab of the vehicle by two switches, 81 and 82, which are mounted on a panel 83. One switch activates the compressor 56 and the uplock solenoid 75, and the other activates the valve 57. The wiring of the switches is shown in schematic form in FIG. 8. Mechanically, the switch wiring 84 is run out to the front of the vehicle and is terminated with a standard 3 prong, female grounding plug 86. A male plug portion 85 is attached to the compressor/valve wiring 88, which is installed on the plow. This arrangement allows the plow to be removed from the vehicle in three steps: First, the compressor and valve are disconnected at plug 86 - 87, second, the pin 63 is removed from the frame member 60, and finally, the plow is pulled out of the frame, using the handle 44 for assistance.
It is intended that the present disclosure should not be construed in any limited sense other than that limited by the scope of the following claims having regard to the teachings herein and the prior art being apparent with the preferred form of the invention disclosed herein and which reveals detail of structure of a preferred form necessary for a better understanding of the invention and may be subject to modification by skilled persons within the scope of the invention without departing from the concept thereof. | A snow plow, designed to fit on small vehicles, is disclosed. The plow has a single point connection to the vehicle. A novel yoke mounting scheme is also disclosed, which enables the blade to be angled. The plow is operated by a pneumatic means, controlled from within the vehicle. All operating connections to the vehicle are made through a single power cord. All pneumatic lines are self contained within the plow, thereby eliminating the need for air hoses to be connected or installed on the vehicle. The plow has an upstop device that is used to block upward travel of the plow. The upstop is used to prevent the plow from obscuring the headlights of the vehicle. An uplock is also provided which acts to lock the plow blade in an non-operating position when the plow is not needed, thereby preventing the possibility of the blade dropping to the road and causing an accident. The plow is designed to be removed quickly and easily from the vehicle for storage. | 4 |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to center-cutters in general, and to center-cutters with cutting jaws mounted swingably around bearing pins, in which the mounting is formed by means of straps connecting the cutting jaws behind teh cutting-jaw region and of a tooth-space engagement fastening the two cutting jaws to each other, in particular.
Side-cutters are known (for instance, Federal Republic of Germany OS 28 39 942), in connection with which the crossover overlapping of the plier arms, which is typical of pliers, is present in the region of the joint, i.e. the right arm of the pliers forms the left cutting jaw and the left arm of the pliers forms the right cutting jaw. The cutting jaws are mounted on a common joint pin. The cutting performance of such tools is adapted to the normal case.
Tools which apply a higher cutting force, so-called bolt-cutters with center-cutter, are available on the market. They operate with a lever transmission. For this purpose, the cutting jaws are each mounted on a separate pin. The handle-side jaw ends are pivotally connected to handles which are mounted one below the other via a joint pin. In this connection, the handles form double levers. The shorter lever acts on the end of the cutting jaws. Corresponding developments are relatively expensive. The cutting jaws are mounted or connected with respect to each other by straps and a tooth-space engagement. From Federal Republic of Germany OS 34 27 990 it is known, on such a bolt-cutter, to develop the shorter lever arm of the handle double lever, and therefore the handle heads, as cam-like crank parts which act in pairs and rest against each other. The handle heads are connected via a transverse strap. The latter engages on end bearing pins of the handle heads. This solution is found even more expensive.
SUMMARY OF THE INVENTION
It is an object of the invention to increase by simple means the cutting power of a tool of the introductory-mentioned type while retaining the classic cross-over overlapping and therefore the development of handle and pliers jaw in one piece.
According to the invention, the plier arms cross over without joint pin. While retaining the basic length of the tool, the force arm is longer; the means of articulation are now shifted into the head or cutting region. The cross-over region of the handles, which is free of a joint pin, can be used as a guide surface. Increased cutting power is accordingly optimized by a simple means in the manner that the cutting edges debouch into the outer surface of the toothspace engagement. The length of the load arm taken up by the joint surface between joint pin and the end of the cutting edge on that side is now a cutting edge.
In accordance with other features of the invention, one proceeds structurally further in the manner that a cylindrical roller body which forms the tooth-space engagement extends transverse to the cutting edge of wedge-shaped cross section and in each case is received in a corresponding penetration hollow formed by two hollow sections in the cutting edges in the manner that an approximately right-angle transition is obtained between the facets of the cutting edges and the walls of the hollow section. This leads to an extremely good cutting action; high cutting forces can be applied under very stable mounting conditions. The individual mounting of the cutting jaws in the strap via the cutting jaws results, in combination with the interposed rolling bodies, in an ideal fulcrum in the direct vicinity of the cutting edge. As a whole, there is, so to speak, a three-point attachment of the cutting-active region of the side- cutters. The penetration hollow which is formed to receive the rolling member proportionately in the cutting regions can not only be produced in a structurally simply manner (this zone is completely free for working) but, as a result of the enlargement of the supporting surface of the wall for the rolling member which increases in the depth of the hollow, creates a firm form-locked abutment for the rolling member. With increasing closing, which goes hand-in-hand with the occurrence of the cutting forces, this bottom, which favors a guiding of the rolling member, presses still more firmly against the outer surface of the rolling member; shearing forces which may cause a displacement of the jaws are rather taken up without damage. This is contributed to, not least of all by the fact that the facets pass at a right angle into walls of the hollow section. Relative or parallel displacements of the cutting jaws with respect to each other are in this way excluded. In this connection, as a further development of the invention, it proves advantageous that the lines of greatest length of the walls of the hollow section travel on the rolling member upon a closing of the center-cutters into a diametrically opposite position. Upon closing, an equal loading in optimally centered position of the cutting jaws is obtained, and therefore specifically in a phase in which the straps are under maximum tensile stress. It is furthermore of advantage that the rolling member snaps over a transverse plane defined by bearing pins of the pliers arms into a handle-side hyperextension position. With tight development of the tooth gap engagement, there is present a snapping action which secures the closing position and can be intentionally, or, in any event, noticeably, overcome in order to open the center-cutters. Furthermore, it proves favorable for the cutting action that the hollow sections are so arranged in the cutting edges that the rolling member protrudes partially beyond the cutting-edge-side strap edge when the center-cutters are open. In this way, the innermost narrowing point (vertex) of the angular cutting jaw lies free. The object to be cut can be placed deep and, in particular, as close as possible in the region of the ideal joint pin. With the closing of the cutting jaw, the rolling member is even pulled further inwardly, i.e. out of this protruding position to beneath the straps which are arranged in pairs. This results, in practice, even in a pulling in of the wire section to be cut. Since the cross section of the rolling member moves away under the straps, there is a bending movement, so that the cutting notch in the case of harder material even leads in superimposed manner to a break behavior. It is furthermore advantageous that the hollow sections are of lenticular shape as a result of the penetration. Furthermore, it is proposed that the rolling member be fastened in one of the hollow sections. The number of structural parts is accordingly reduced. The fastening can be effected by brazing. One development which is particularly favorable for manufacture is that the rolling member of one or the other cutting edge be developed as an identically forged projection. This reduces, in particular, the number of parts and the play. Furthermore, it is advantageous with respect to the force-favorable handling that the handles form, at a hand-width distance from the free end of the handle, a fillet which lies at a corresponding distance from the cross-over region of the plier arms, the handle sections which extend from this fillet extending curved outwardly in arched manner and the free end sections adjoining a second fillet assuming a slightly diverging course. In this way, good ergonometric conditions are present. Finally, the invention also proposes that the cutting edges pass, adjoining a jaw taper step, into the full thickness of the cutting jaws. In this way, the portions of the cutting jaws that are lying flat on the straps are considerably broader. The guidance is accordingly a large-area guidance and therefore better. The cutting edges are seated practically in the manner of a ledge on the sides of the cutting jaws facing each other.
BRIEF DESCRIPTION OF THE DRAWING
With the above and other objects and advantages in view, the present invention will become more clearly understood in connection with the detailed description of preferred embodiments, when considered with the accompanying drawings, of which:
FIG. 1 shows the center-cutters developed in accordance with the invention; seen in side view;
FIG. 2 is a view of FIG. 1 seen from the left-hand narrow side;
FIG. 3 is a top view of FIG. 1;
FIG. 4 is a corresponding bottom view;
FIG. 5 shows the center-cutters with cutting jaws open;
FIG. 6 is an enlarged view of the head of the center-cutters in closed position;
FIG. 7 is a similar view in an open position;
FIG. 8 is a section along the line VIII--VIII of FIG. 6, further enlarged;
FIG. 9 is a perspective view of the rolling member arrangement on one of the cutting jaws;
FIG. 10 is a view, similar to FIG. 6, of a modified embodiment; and
FIG. 11 shows the plier of FIG. 6 in open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The center-cutters shown has two handles 1,2 which are continued, crossing over the region of the joint, in, in each case, into cutting jaw 3,4.
Each handle 1,2 is turnably mounted on a special bearing pin 5 or 6, respectively, said pins extending on both sides of the axis of symmetry x--x of the side-cutters. They lie on a common transverse plane E--E to same as well as transverse to the plane of swing of the cutting jaws.
The bearing pins 5,6 pass through cross sectionally adapted passage openings of two straps 7. These flat straps, which are arranged in pairs and extend in the plane of swing of the cutting jaws 3,4 and handles 1,2, hold, guided between them, the transition region between the cutting jaws 3,4 and handles 1,2. The straps 7, which are cut basically in a long rectangle, have their longer side extending in the direction of the transverse plane E--E (see FIG. 1).
For the fastening of the bearing pins 5,6, the latter have heads on one side and are riveted on the other side. The heads are of frustoconical shape and the rivetings are transversely rounded.
In the region of cutting edges 8,9 of the cutting jaws 3,4, which are directed toward each other, the straps 7 have a rounded niche 10. The latter has a centering action for the object to be cut, for instance wire.
At the same distance from the bearing pins 5,6 there is arranged between them a rolling member 11. The latter forms a sort of tooth-space engagement ZL between the cutting jaws 3,4 and is of cylindrical shape. Its edges are beveled (FIG. 8). Its axial length corresponds to the inside distance between the straps 7 which are arranged parallel to each other or, stated more precisely, the thickness, measured in this direction, of the cutting jaws 3,4. The cylindrical rolling member 11 which thus extends transversely to the cutting edges 8,9 is seated in each case proportionally in a corespondingly formed penetration hollow 12 of two hollow sections I,II of the cutting edges 8,9. Since the cutting edges 8,9 are of wedge shape and the rolling member 11 is of cylindrical shape, the hollow sections I,II have a lenticular wall contour (see FIG. 9). The facet 8' or 9' of the respective cutting edge 8 or 9 which extends on the cutting-edge side to the outer wall of the cylindrical roller member 11 comes to a point at the region of transition to the hollow sections I,II. Starting from there, the wall of the hollow section I,II is increasingly enlarged so that its line L of transverse extent has its greatest length approximately at the transverse plane E--E. From there the area of the wall decreases again correspondingly.
In the closed position of the pliers, this line L of transverse extent both hollow sections I,II forming the receiver for the rolling member lies at least in the direct connecting line between the center lines y-y of the two bearing pins of 5,6. In a preferred embodiment (cf. FIG. 6), the rolling member 11 even assumes a position which extends beyond this line in the direction of the handles 1,2.
Accordingly, in the final phase of the cutting movement there is an increasingly firm insertion of the rolling member 11 in the penetration hollow 12. From this follows a precise pivotal support of the cutting edge. All parallel displacement of the cutting jaws 3,4 is prevented.
Since the line L of both hollow sections I,II passes into a position of hyper-extension, even though only slightly so (FIG. 6), the corresponding passage over the dead center can be utilized in practice also for a dependable securing of the center-cutters in the stop-limited closed position. The lever leading to this line, which extends from the longitudinal axis y--y, is designated H. It forms an acute angle of only a few degrees with the transverse plane E--E, for which reason the passage beyond the dead center position upon sufficiently tight insertion of the rolling member 11 can be noted as merely a slight clamping position which, however, is entirely sufficient for the purpose indicated. In each case a toggle-lever-like passage takes place.
The hollow sections I,II in the cutting edges 8,9 are furthermore so arranged that the rolling member 11, with the side- cutters open, protrudes in part beyond the cutting-edge-side strap edge with respect to the base of niche 10. To this extent, the opening jaw travels in the direction toward the object to be cut. This, and the fact that the entire length of the facet 8' or 9' up to the outer wall of the rolling member 11 is available for the cutting section, results in an extremely good cutting performance and convenient handling. With the closing of the handles 1,2 of the center-cutters, the rolling member, which rests via its end surfaces on the inner surfaces of the straps 7, travels back again into its position of complete axial area support. The beveled edges avoid any wear. In the open position, about half the cross-sectional area of the rolling member is free.
The cutting edges 8,9 connect via a definite step 13 into the maximum jaw thickness. This jaw taper step 13 is located on both sides of the cutting jaws 8,9. The reduction is about 50%. The transition into the thicker section of the cutting jaws 3,4 is concavely rounded and bears the reference numeral 14. The cutting edges 8,9, which taper outwardly after the jaw reduction step 13, pass into the blunter facet 8' and 9', respectively. The cutting line coincides with the longitudinal center line x--x of the center-cutters on which the rolling member moves. The cutting angle Alpha X of the cutting edges 8,9 is 40°. The interruption in the course of the cutting flank as a result of the step 13 results in an increase in area of the width z for the strap-side guidance of the cutting jaws 3,4. In this connection, z corresponds to somewhat more than the radius of the rolling member.
The crimped cross-over region of the handles 1,2 which adjoins behind the straps 7 on the handle side, is clearly widened as compared with the handle and jaw zone, in the interest of the large-area guide surfaces 15.
In accordance with a variant shown in FIGS. 10 and 11, the tooth-space engagement ZL is so developed that the rolling member 11 is fastened in one of the hollow sections I,II. The fastening can be effected by brazing. There is preferred, however, a development such that the rolling member 11 is associated with one or the other cutting edges 8,9, in this case the cutting edge 9, as a directly forged-on projection. The projection has the shape of half a rolling member, divided as seen in axial view. The supportactive outer surface takes into consideration the need of movement for the opening of the jaw and is therefore somewhat larger than said half.
Otherwise the same construction is present as described. The reference numbers have therefore been employed in corresponding manner, without repetition of the text.
The outer wall of the developed rolling member 11 is continued in FIGS. 10 and 11, to be sure, also as a penetration line, but for a clearer understanding of the nature of the single part, the fastening-jaw-side arc line has, however, been omitted.
Directly behind the cross-over region, the handles 1,2 form stop spurs 16 which are directed against one another and which define the closed position of the cutting edges 8,9.
The limitation of the opening is formed by handle-side diverging sections 8" and 9" of the cutting jaw parts which lie on the other side of the penetration hollow 12.
The length ratio of cutting jaw 3 and 4 to handle 1 and 2 is about 1:10. Half the length of the cutting edge 8,9 devolves on the lever H.
An insulation 17 is applied, preferably shrunk, onto the slightly undulated handles 1,2.
The undulation of the handles is of such a nature that the handles 1,2 form on the outside a fillet 18 the distance of the width of the hand from the free end of the handles. The fillet 18 of both handles 1,2 lies on a common transverse plane. The distance between fillet 18 and the free ends of the handle is approximately the same as the distance between the lowest point of the fillet 18 and the cross-over region K. These spacing zones are curved outwardly and therefore impart the entire handle two more bulged zones. The insulation 17 terminates approximately in the center of the plier-head-side handle section. As can be noted from the drawing, the free end sections adjoining a second outside fillet 19 present there have assumed a slightly diverging course. All sections pass arched into one another.
The first fillet 18 and the total curved section adjoining the handle-end side permits an optimal grasping hold adapted to the ergonometric conditions of the operating hand, with the resting of the root of the thumb in one or the other first fillets 18. The four fingers of the operating hand grip over the arched section of the other handle. Since the handle sections have an arching which corresponds to the arching of the palm of the hand, high actuating forces can be applied.
The double-barrel shape of the handle as seen in silhouette even makes possible operation with two hands since the handle sections are of the same length on both sides of the first fillet 18 and therefore the two of them have a spacing equal to the palm of the hand.
On the other hand, the handles 1,2 are so spaced from each other that fingers extending, for instance, into their intermediate space 20 cannot be pinched. | A center-cutter with cutting jaws mounted swingably around bearing pins, the mounting being formed by means of straps connecting the cutting jaws in the back of the cutting-jaw region and of a tooth-space engagement connecting the two cutting jaws to each other. While retaining the known cross-over overlapping of a single piece formation of handles and pliers jaws, handles cross over without joint increasing the cutting output. | 1 |
This application claims the priority of U.S. Provisional Application No. 61/427,643, filed Dec. 28, 2010.
FIELD OF INVENTION
The field relates to an acoustic building material or fiber board as well as a method for its manufacture, and more particularly, to fiber board containing homogenously dispersed chitosan within the board construction.
BACKGROUND OF INVENTION
The acoustic building material or fiber board may be in the form of a ceiling tile, a ceiling panel, a wall panel or wall tile as are well known in the building trades. The boards are prepared from a slurry of fibers, fillers and binders.
The boards are typically prepared using the slurry in a water felting process as is known in the art. A dispersion of fiber, filler, binder and other ingredients flow onto a moving, porous support such as a Fourdrinier forming machine for dewatering. The dispersion is dewatered first by gravity and then by vacuum suction. The wet base mat is dried and the dried material is cut to the desired dimensions and optionally top coated to produce the fiber board panels or tiles.
Chitosan or poly-D-glucosamine is commercially available as a deacetylated form of chitin which is a structural element in the exoskeleton of crustaceans and the cell walls of certain fungi. It is a cationic polymer similar to cellulose. Chitosan has been found to promote blood clotting and it has been used in bandages. It is a biocide and has special properties that enhance antimicrobial and antifungal activities. Chitosan is also used as a flocculent in the water filtration of heavy metals. Chitosan is also indicated to absorb formaldehyde and odor.
BRIEF DESCRIPTION OF THE INVENTION
Chitosan has been found to be a multifunctional additive to fiber board that may be incorporated directly into the slurry formulation. The chitosan is dissolved in acid and added directly to the slurry as a dilute solution. In this manner, the chitosan is uniformly dispersed through the board construction with no substantial change in the manufacturing process.
The use of chitosan in fiber board constructions enables a number of advantages in the resulting product. For example, chitosan concentrations less than about 10 wt % provide structural reinforcement sufficient to permit reduction of the amount of binder. This results in a cost saving since the binder is an expensive ingredient in the fiber board composition.
A further advantage of incorporating chitosan in board constructions is that it enhances and contributes to the binding of the components and enables recycle content to be increased. That is, the amount of binder may be decreased and increased amounts of recycle cellulose may be used.
Most surprisingly, the incorporation of chitosan in the board construction has also been found to enhance dewatering or water removal from the board constructions as they are formed and to reduce the drying requirement. In the felting process, the water removal from the board construction is improved prior to the oven drying step and the amount of drying required is reduced. In board construction processing including chitosan in accordance with the invention, the amount of water removed in the dewatering steps prior to oven drying is increased and therefore the amount of water to be removed in a final oven drying step is decreased. The reduced oven drying requirement saves energy and expense.
The biocidal properties of chitosan are directly useful in ceiling and wall applications. These properties are especially valuable in ceiling tile applications where high humidity, condensation or other sources of moisture are likely to wet the tile. Such high humidity environments are friendly to undesirable microbial and fungal growth which may be deposited by airborne transfer.
The ability of chitosan to absorb formaldehyde is believed to reduce both process and product formaldehyde levels. The odor absorbing properties of chitosan are particularly useful in product applications.
DETAILED DESCRIPTION OF THE INVENTION
As indicated above, chitosan has been found to provide desirable characteristics to acoustical building materials or fiber boards as a multifunctional additive. For convenience, the invention is described below with particular reference to ceiling tiles which may be used in a suspended ceiling.
The ceiling tiles of interest herein include base fibers that are usually mineral fibers such as mineral wool or glass fibers and organic fibers such as cellulose fibers. The fillers are commonly perlite, clay, calcium carbonate, or stucco gypsum. The binder is typically starch, latex, or similar materials. These materials or ingredients are typically combined in aqueous slurry and processed in a water felting process as described above.
In typical compositions, the fiber and filler components comprise the primary ingredients. However, a wide variation of ingredients may be employed. For example, the following chart summarizes typical ceiling and wall compositions. It should be appreciated that compositions may contain one or more of the illustrative types of fiber, filler or binder as listed in the following table. The percentages herein are weight percent based on solids unless otherwise indicated by comment or context.
Ingredient
Range %
Preferred %
Fiber
Mineral wool
5-65%
19-35%
Glass fiber
5-65%
19-35%
Cellulose fiber
0-25%
18%
(recycle paper)
Filler
Perlite
15-70%
30-52%
Clay
0-25%
4%
Calcium carbonate
0-20%
10%
Binder
Corn starch
3-12%
8%
Latex
0-5%
3%
Chitosan
1-6%
2%
The fiber, filler and binder components are combined in aqueous slurry at a level of about 3% to 6% solids in a known manner. The chitosan is dissolved in an acidic aqueous solution and homogenously blended into the slurry. For example, the chitosan in powder or chip form may be dissolved in a 2-4% by volume acetic acid solution and added to the slurry. The chitosan solution is added in an amount that provides a final product weight basis amount in the range of 1% to 6% based on the solids contained in the slurry.
It is believed that the hydrophilic OH and NH groups present in the chitosan enhance the uniform distribution of the chitosan and the thorough penetration and/or contact with the fiber and filler slurry ingredients. Also, the cationic charged chitosan is believed to interact with the starch. Further, the chitosan appears to form a fiber-like structure that is intertwined and/or otherwise interacted with the other fiber components of the tile to provide a structural reinforcement that enables the amount of binder to be reduced with acceptable limited change in the tile physical properties.
As described above, the addition of chitosan to board constructions for ceiling tile or the like reduces the amount of water retained by the construction as it is formed prior to oven drying. The felting process may include natural drainage, application of vacuum and/or roll pressing of the board in order to remove water prior to oven drying. The use of chitosan in accordance with the invention has been found effective to enhance water removal when used with one or more of the foregoing pre-oven drying processes. Accordingly, a chitosan containing board in accordance with the present invention contains less water prior to oven drying than an identically formed board construction having the same composition except for the addition of chitosan.
The following illustrative examples compare boards corresponding with the core of the tile and do not include outer coatings, holes or other finish treatments. The board composition includes mineral wool, recycle newsprint, starch from corn, calcium carbonate, perlite and flocculent. It has been empirically determined that the amount of corn starch is preferably about 8 wt % to provide the desired acoustic, strength and other properties. Herein, the board composition was modified to incorporate various amounts of chitosan and reduced amounts of starch to demonstrate the binding and reinforcing properties of chitosan.
The absolute amounts of components contained in the prepared boards are reported in following Table 1.
TABLE 1
Formulations (by Dry Weight)
Corn
Calcium
Board
Mineral
News
Chitosan
Starch
Carbonate
Perlite
Flocculent
#
Wool (g)
(g)
(g)
(g)
(g)
(g)
(g)
1
42.4
73.3
0.0
30.8
38.6
200.5
0.3
2
42.2
72.9
1.9
30.7
38.4
199.5
0.3
3
42.6
73.6
1.9
27.1
38.7
201.5
0.3
4
43.1
74.4
2.0
23.5
39.1
203.5
0.3
5
43.9
75.9
2.0
16.0
40.0
207.8
0.3
Board 1 provides a control with no added chitosan and the typical amount of starch. Boards 2-5 contain increasing amounts of chitosan and decreasing amounts of binder starch.
The weight percent by parts of the various components for Boards 1-5 is shown in Table 2.
TABLE 2
Formulation (% by Parts)
%
%
Board
Mineral
%
%
Corn
%
%
%
#
Wool
News
Chitosan
Starch
CaCO 3
Perlite
Flocculent
1
11
19
0.0
8
10
52
0.08
2
11
19
0.5
8
10
52
0.08
3
11
19
0.5
7
10
52
0.08
4
11
19
0.5
6
10
52
0.08
5
11
19
0.5
4
10
52
0.08
Boards 1-5 were tested and the results are set forth in below Table 3. The following test procedures were used in determining the test results reported in Table 3.
The MOR test for modulus of rupture is a 3-point bend test. The test procedure herein is similar to ASTM C 367 Standard Test Methods for Strength Properties of Prefabricated Architectural Acoustical Tile or Lay-In Ceiling Panels. The hardness test indicates a ceiling tiles ability to resist indentation which may occur during installation or post-installation. The 2″ ball hardness test used herein is similar to ASTM C 367 Standard Test Methods of Strength Properties of Prefabricated Architectural Tile or Lay-In Ceiling Panels.
TABLE 3
Physical Measurements; MOR; Hardness
Board
Weight
Length
Width
Caliper
Density
MOR
Breakload
Hardness
#
Sample
(g)
(in)
(in)
(in)
(lb/ft 3 )
(psi)
(lb)
(lbf)
1
A
49.64
10.037
3.029
0.679
9.16
64.3
7.48
103.6
B
49.77
10.037
3.029
0.684
9.11
61.8
7.30
90.2
C
50.51
10.037
3.029
0.696
9.08
61.8
7.55
106.2
Average
49.97
10.037
3.029
0.686
9.12
62.6
7.44
100.0
STDEV
0.47
0.00
0.00
0.01
0.04
1.44
0.13
8.59
2
A
49.90
10.036
3.028
0.668
9.36
62.8
7.07
99.1
B
51.15
10.036
3.028
0.676
9.48
71.2
8.21
105.3
C
52.72
10.036
3.028
0.685
9.64
77.6
9.18
107.5
Average
51.26
10.036
3.028
0.676
9.49
70.5
8.15
104.0
STDEV
1.41
0.00
0.00
0.01
0.14
7.42
1.06
4.36
3
A
49.95
10.041
3.026
0.683
9.16
56.2
6.61
89.3
B
51.12
10.041
3.026
0.687
9.32
61.4
7.31
99.4
C
52.78
10.041
3.026
0.701
9.44
64.2
7.95
98.6
Average
51.28
10.041
3.026
0.690
9.31
60.6
7.29
95.8
STDEV
1.42
0.00
0.00
0.01
0.14
4.06
0.67
5.61
4
A
49.24
10.036
3.026
0.684
9.03
54.2
6.39
90.9
B
49.94
10.036
3.026
0.687
9.12
61.5
7.32
96.2
C
53.07
10.036
3.026
0.701
9.49
64.9
8.04
101.2
Average
50.75
10.036
3.026
0.690
9.21
60.2
7.25
96.1
STDEV
2.04
0.00
0.00
0.01
0.25
5.47
0.83
5.15
5
A
49.79
10.039
3.025
0.680
9.18
47.8
5.58
88.6
B
51.52
10.039
3.025
0.689
9.38
50.9
6.09
86.9
C
53.88
10.039
3.025
0.705
9.59
50.7
6.35
100.6
Average
51.73
10.039
3.025
0.691
9.38
49.8
6.01
92.0
STDEV
2.05
0.00
0.00
0.01
0.20
1.73
0.39
7.47
Comparison of Boards 1 and 2 shows an increase in strength and hardness as indicated by the increased MOR, break load and hardness results. This comparison includes like amounts of binder with the addition of chitosan in Board 2. Thus, the chitosan increased these physical properties.
The amount of binder in Boards 2 and 3 is respectively reduced by 1% and 2%. The reduction in binder is not fully compensated for by the chitosan addition. Thus, Boards 3 and 4 are slightly weaker and softer, but within acceptable physical property value range. As used herein, acceptable physical properties means tested physical property values at least equal to about 95% of the values provided by an identically formed ceiling tile using the same ingredients except for the addition of the chitosan.
Even though slightly lower properties values may result, it should be appreciated that the more costly starch ingredient is reduced in amount in the constructions of Boards 2 and 3. In addition, the recycle newsprint may be increased in amount to replace the reduced starch content and to thereby increase the recycle and postindustrial/postconsumer content of the tile.
Board 5 is characterized by a decrease in strength and hardness greater than 5% of the control value. Such a decrease is presently deemed to exceed acceptable physical property values. Again, the recycle newsprint may be increased in amount to replace the reduced starch content and to thereby increase the recycle and postindustrial/postconsumer content of the tile.
Boards 1-5 were tested for their noise reduction, and more particularly, ENRC or the estimated noise reduction coefficient was determined. The ENRC test is based on ASTM C 384 Standard Test Method for Impedance and Absorption of Acoustical Material by the Impedance Tube Method. This test is used to predict sound absorption. It should be appreciated that the test results are only comparable for similarly prepared samples, e.g., the boards herein do not include further surface finishes or the like final treatments.
The test results are reported in following Table 4.
TABLE 4
ENRC
Board #
Sample
ENRC
1
A
0.33
B
0.30
C
0.29
Average
0.31
STDEV
0.02
2
A
0.31
B
0.31
C
0.29
Average
0.30
STDEV
0.01
3
A
0.30
B
0.29
C
0.33
Average
0.31
STDEV
0.02
4
A
0.30
B
0.33
C
0.31
Average
0.31
STDEV
0.02
5
A
0.37
B
0.28
C
0.30
Average
0.32
STDEV
0.05
As shown in Table 4, the use of chitosan does not detrimentally affect the ENRC, and the advantages of chitosan may be achieved without unacceptable reductions in this property.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. | An acoustic building material and method for manufacture incorporates chitosan in an amount sufficient to achieve acceptable physical properties with a reduction in binder and to allow the postindustrial/postconsumer content of the building material to be increased. The chitosan also enhances the dewatering of the building material. | 4 |
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to gas turbine systems, and more particularly to a combustor liner cooling assembly.
[0002] A combustor section of a gas turbine system typically includes a combustor chamber disposed relatively adjacent a transition piece, where a hot gas passes from the combustor chamber through the transition piece to a turbine section. At least a portion of the combustor chamber is often surrounded by a flow sleeve, while at least a portion of the transition piece is surrounded by an impingement sleeve. The flow sleeve typically includes a plurality of apertures for providing impingement cooing for portions of a liner of the combustor. An additional airflow passes from a region defined by the impingement sleeve and the transition piece to a region defined by the flow sleeve and the combustor liner. The impingement cooling of the liner of the combustor is achieved by cooling jets that are pushed onto the liner in a direction relatively perpendicular to the additional airflow flowing from the region proximate the impingement sleeve to the region proximate the flow sleeve. The additional airflow often disrupts the cooling jets, thereby resulting in reduced cooling efficiency.
BRIEF DESCRIPTION OF THE INVENTION
[0003] According to one aspect of the invention, a combustor liner cooling assembly for a gas turbine system includes a combustor liner defining a combustor chamber. Also included is a flow sleeve surrounding at least a portion of the combustor liner, wherein the flow sleeve includes at least one aperture row comprising a plurality of apertures, each of the plurality of apertures impinging a cooling flow jet onto the combustor liner. Further included is a plurality of flow redirecting components disposed proximate an aft end of the flow sleeve, wherein the plurality of flow redirecting components divert an impingement cross-flow flowing relatively perpendicular to the cooling flow jet, thereby providing the cooling flow jet an undisturbed flow path to the combustor liner.
[0004] According to another aspect of the invention, a combustor liner cooling assembly for a gas turbine system includes a combustor liner defining a combustor chamber. Also included is a flow sleeve surrounding at least a portion of the combustor liner and having an aft end, wherein the flow sleeve includes a plurality of apertures for impinging a plurality of cooling flow jets onto the combustor liner. Further included is an impingement sleeve disposed proximate the aft end of the flow sleeve, wherein an impingement flow path is defined by the impingement sleeve and a transition duct, wherein an impingement cross-flow flows through the impingement flow path into a region between the flow sleeve and the combustor liner. Yet further included is a plurality of flow redirecting components disposed proximate the aft end of the flow sleeve, wherein the plurality of flow redirecting components divert the impingement cross-flow.
[0005] According to yet another aspect of the invention, a combustor liner cooling assembly for a gas turbine system includes a combustor liner defining a combustor chamber. Also included is a flow sleeve surrounding at least a portion of the combustor liner and having an aft end, wherein the flow sleeve includes a plurality of aperture rows, wherein each of the plurality of aperture rows comprises a plurality of apertures extending circumferentially around the flow sleeve, wherein each of the plurality of apertures impinges a cooling flow jet onto the combustor liner. Further included is a plurality of flow redirecting components disposed on a forward sleeve located proximate the aft end of the flow sleeve and a forward end of an impingement sleeve, wherein each of the plurality of flow redirecting components is circumferentially aligned with a corresponding first row aperture for diverting an impingement cross-flow entering a region between the flow sleeve and the combustor liner proximate the aft end of the flow sleeve.
[0006] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0007] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0008] FIG. 1 is a partial schematic illustration of a combustor section of a gas turbine system;
[0009] FIG. 2 is an enlarged view of section II of FIG. 1 , illustrating a combustor liner cooling assembly;
[0010] FIG. 3 is a perspective view of a plurality of flow redirecting components of the combustor liner cooling assembly;
[0011] FIG. 4 is an enlarged, perspective view of a flow redirecting component of the plurality of flow redirecting components of a first embodiment;
[0012] FIG. 5 is a cross-sectional view of a flow profile proximate the flow redirecting component of the first embodiment of FIG. 4 ;
[0013] FIG. 6 is a perspective view of the flow redirecting component of a second embodiment;
[0014] FIG. 7 is a perspective view of the flow redirecting component of a third embodiment;
[0015] FIG. 8 is a perspective view of the flow redirecting component of a fourth embodiment;
[0016] FIG. 9 is a perspective view of the flow redirecting component of a fifth embodiment; and
[0017] FIG. 10 is a perspective view of the flow redirecting component of a sixth embodiment.
[0018] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to FIG. 1 , partial schematic illustrates a combustor section of a gas turbine system and is referred to generally with numeral 10 . The combustor section 10 includes a transition piece 12 having a transition duct 14 at least partially surrounded by an impingement sleeve 16 disposed radially outwardly of the transition duct 14 . Upstream thereof, proximate a forward end 18 of the impingement sleeve 16 is a combustor liner 20 defining a combustor chamber 22 . The combustor liner 20 is at least partially surrounded by a flow sleeve 24 disposed radially outwardly of the combustor liner 20 . A forward sleeve 26 is located at the junction between the forward end 18 of the impingement sleeve 16 and an aft end 28 of the flow sleeve 24 .
[0020] The combustor section 10 uses a combustible liquid and/or gas fuel, such as a natural gas or a hydrogen rich synthetic gas, to run the gas turbine system. The combustor chamber 22 is configured to receive and/or provide an air-fuel mixture, thereby causing a combustion that creates a hot pressurized exhaust gas. The combustor chamber 22 directs the hot pressurized gas through the transition piece 12 into the turbine section (not illustrated), causing rotation of the turbine section. The presence of the hot pressurized exhaust gas increases the temperature of the combustor liner 20 surrounding the combustor chamber 22 , particularly proximate a downstream end 30 of the combustor liner 20 . To overcome issues associated with excessive thermal exposure to the combustor liner 20 , a plurality of apertures 32 within the flow sleeve 24 are arranged to provide impinged air in the form of a plurality of cooling jets 34 onto the combustor liner 20 . The plurality of apertures 32 may optionally include “thimbles” (not illustrated) which protrude toward the combustor liner 20 , providing an enclosed region to deliver the plurality of cooling jets 34 toward the combustor liner 20 . An impingement cross-flow 36 flows relatively perpendicularly to the plurality of cooling jets 34 and provides a convective cooling effect on the combustor liner 20 while flowing from downstream to upstream along the combustor liner 20 . Specifically, the impingement cross-flow 36 flows from a region defined by the impingement sleeve 16 and the transition duct 14 to a region defined by the flow sleeve 24 and the combustor liner 20 .
[0021] Referring to FIG. 2 , an enlarged view of the aft end 28 of the flow sleeve 24 , the forward sleeve 26 and the forward end 18 of the impingement sleeve 16 is shown in greater detail. The plurality of apertures 32 within the flow sleeve 24 may be arranged in one or more circumferential rows proximate the aft end 28 of the flow sleeve 24 . The forward sleeve 26 includes at least one, but typically a plurality of flow redirecting components 38 operably coupled thereto that are disposed along an inner surface of the forward sleeve 26 in a circumferentially spaced arrangement. The plurality of flow redirecting components 38 may be integrally formed with the forward sleeve 24 or may be fastened thereto. Each of the plurality of flow redirecting components 38 includes a flow redirecting surface 40 that is arranged to interact with the impingement cross-flow 36 that is flowing upstream toward the combustor liner 20 and the flow sleeve 24 . Each of the plurality of flow redirecting components 38 is relatively circumferentially aligned with at least one of the plurality of apertures 32 .
[0022] Although the plurality of flow redirecting components 38 are described above and illustrated as being operably coupled to the forward sleeve 26 , it is contemplated that alternative embodiments may include operable coupling of the plurality of flow redirecting components 38 to the impingement sleeve 16 proximate the forward end 18 thereof Additionally, it is contemplated that the plurality of flow redirecting components 38 may be operably coupled to the aft end 28 of the flow sleeve 24 , provided that the plurality of flow redirecting components 38 are disposed downstream of the plurality of apertures 32 .
[0023] Referring to FIGS. 3-5 , a first embodiment of the plurality of flow redirecting components 38 comprises a semi-circular geometry, with the flow redirecting surface 40 arranged to interact with the impingement cross-flow 36 , as described above. As the impingement cross-flow 36 interacts with the flow redirecting surface 40 , the impingement cross-flow 36 is diverted around the flow redirecting surface 40 . As noted above, the plurality of flow redirecting components 38 are relatively aligned with the plurality of apertures 32 , and therefore also the plurality of cooling jets 34 flowing relatively perpendicularly to the impingement cross-flow 36 . By diverting the impingement cross-flow 36 , a disturbance of each of the plurality of cooling jets 34 is reduced based on the lack of a direct interaction between the impingement cross-flow 36 and the plurality of cooling jets 34 , thereby allowing the plurality of cooling jets 34 to more efficiently cool the combustor liner 20 . Additionally, the diversion of the impingement cross-flow 36 increases the average velocity of the impingement cross-flow 36 , which increases the convective heat transfer associated with the flowing of the impingement cross-flow 36 over the combustor liner 20 .
[0024] Referring now to FIG. 6 , a second embodiment of the plurality of flow redirecting components 38 is shown and is similar in construction to that of the first embodiment illustrated in FIGS. 3-5 . Specifically, the second embodiment of the plurality of flow redirecting components 38 includes a plurality of holes 42 for reducing the formation of vortices upon recirculation of the impingement cross-flow 36 subsequent to passing the flow redirecting surface 40 .
[0025] Referring to FIG. 7 , a third embodiment of the plurality of flow redirecting components 38 is illustrated and is similar in construction to the embodiments described above. The third embodiment of the plurality of flow redirecting components 38 includes a first portion 44 having the previously described semi-circular geometry, which includes the flow redirecting surface 40 terminating in a first end 46 and a second end 48 . Extending axially upstream from at least one of the first end 46 and the second end 48 is a second portion 50 that provides additional axial structure for the impingement cross-flow 36 to flow along. The additional structure provided by the second portion 50 reduces the axial space between the plurality of flow redirecting components 38 and the plurality of cooling jets 34 , thereby reducing the likelihood of the impingement cross-flow 36 disrupting the plurality of cooling jets 34 . The third embodiment is illustrated with the plurality of holes 42 described above in relation to the second embodiment, however, it is to be appreciated that the third embodiment may include the second portion 50 , but not the plurality of holes 42 .
[0026] Referring now to FIGS. 8-10 , additional embodiments of the plurality of flow redirecting components 38 are illustrated. The additional embodiments are similar to the embodiments described above, but rather than a semi-circular geometry, the additional embodiments include a triangular geometry. Specifically, a fourth embodiment ( FIG. 8 ) of the plurality of flow redirecting components 38 includes a triangular geometry having a flow redirecting peak 52 arranged to interact with the impingement cross-flow 36 , as described above with respect to the flow redirecting surface 40 of the semi-circular embodiments. Additionally, a fifth embodiment ( FIG. 9 ) includes the plurality of holes 42 . As is the case with the embodiments described above containing the plurality of holes 42 , the plurality of holes 42 may be disposed at various angles and in various numbers and shapes and will be dependent upon the application of use. A sixth embodiment ( FIG. 10 ) includes a first triangular portion 54 extending from the flow redirecting peak 52 to a first end 56 and a second end 58 , where at least one second portion 60 may extend therefrom, similar to the third embodiment described above. As is the case with the third embodiment, although illustrated with the plurality of holes 42 , it is to be appreciated that the sixth embodiment may include the at least one second portion 60 , but not the plurality of holes 42 . The plurality of flow redirecting components 38 are described above as having particular geometric shapes, however, it is to be understood that any suitable geometric shape capable of diverting the impingement cross-flow 36 may be employed as the plurality of flow redirecting components 38 .
[0027] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | A combustor liner cooling assembly for a gas turbine system includes a combustor liner defining a combustor chamber. Also included is a flow sleeve surrounding at least a portion of the combustor liner, wherein the flow sleeve includes at least one aperture row comprising a plurality of apertures, each of the plurality of apertures impinging a cooling flow jet onto the combustor liner. Further included is a plurality of flow redirecting components disposed proximate an aft end of the flow sleeve, wherein the plurality of flow redirecting components divert an impingement cross-flow flowing relatively perpendicular to the cooling flow jet, thereby providing the cooling flow jet an undisturbed flow path to the combustor liner. | 5 |
FIELD OF THE INVENTION
[0001] The present invention is directed generally to the use of shape memory alloys in gas turbine engine components, and specifically to the use of shape memory alloys to control cooling of turbine engine components with changing temperature.
BACKGROUND OF THE INVENTION
[0002] Gas turbine engines operate by burning fuel and extracting energy from the combusted fuel to generate power. Atmospheric air is drawn into the engine from the environment, where it is compressed in multiple stages to significantly higher pressure and higher temperature. A portion of the compressed air is then mixed with fuel and ignited in the combustor to produce high energy combustion gases. The high energy combustion gases then flow through the turbine section of the engine, which includes a plurality of turbine stages, each stage comprising turbine vanes and turbine blades mounted on a rotor. The high energy combustion gases create a harsh environment, causing oxidation, erosion and corrosion of downstream hardware. The turbine blades extract energy from the high energy combustion gases and turn the turbine shaft on which the rotor is mounted. The shaft may produce mechanical power or may directly generate electricity. A portion of the compressed air is also used to cool components of the turbine engine downstream of the compressor, such as combustor components, turbine components and exhaust components.
[0003] In some gas turbine engines, the compressor discharge casing is a complex cast iron structure that locates the combustion hardware (e.g. fuel nozzle, combustion liner and transition pieces) between the compressor exit and the turbine inlet. Air from the compressor is a permitted to leak around the compressor discharge casing to cool the region in front of the first rotor and turbine blade set mounted on the rotor, also referred to as the first forward wheelspace (1FWSP). Of course, the amount of cooling air is determined based on the pressure of the compressor discharge air, which can vary at fixed load conditions based on ambient air temperature. To provide additional cooling, boreplugs are provided in the compressor discharge casing that permits additional compressor discharge air to flow into 1FWSP to provide additional cooling. The number of boreplugs to be opened is based on anticipated cooling flow requirements. If the anticipated cooling flow is incorrect, then cooling either will be inadequate, causing the temperatures in the 1FWSP to be too high, which can result in shortened life expectancy of the components being cooled, or will be excessive, resulting in the unnecessary diversion of compressor air that can result in operational inefficiency. Of course, because the boreplugs are opened or removed on installation based on anticipated cooling flow, correction of the cooling flow by addition or removal of plugs must await maintenance, as removal of a gas turbine from service to accomplish this modification is not cost effective.
[0004] Due to rising fuel costs, natural gas fired power plants that were designed to operate at mostly full power output are now being operated on a intermittent basis. Coal and nuclear energy now generally make up the majority of stable power output. Gas turbines are being increasingly used to make up the difference during peak demand periods. For example, a gas turbine may be used only during the daytime and then taken off line during the night time when the power demand is lower. During load reductions or “turndowns”, gas turbines typically can remain in emissions compliance down to about forty to forty-five percent (40% to 45%) of full rated load output. Below this load, carbon monoxide (CO) emissions can increase exponentially and cause the system as a whole to go out of emissions compliance. Generally described, emissions compliance requires that the turbine as a whole to produce less than the guaranteed or predetermined minimum emissions levels. Such levels may vary with the ambient temperature, system size, and other variables. Especially the turndown capability of the gas turbine goes down in cold ambient, i.e. as the ambient temperature falls, the minimum load for CO compliance rises steeply. If a gas turbine has to be shutdown because it cannot remain in emissions compliance due to a low power demand, the other equipment in a combined cycle application also may need to be taken offline. This equipment may include a heat recovery steam generator, a steam turbine, and other devices. Bringing these other systems online again after a gas turbine shutdown may be expensive and time consuming. Such startup requirements may prevent a power plant from being available to produce power when the demand is high. There may be a strategic operational advantage in being able to keep a gas turbine online and in emissions compliance during periods of low power demand so as to avoid the start up time and expense. The above defined minimum load is a function of combustion temperature. If the combustion temperature drops down below a predetermined value, the CO emission increases. This temperature is a function of fuel air ratio in the combustor. So during gas turbine load reduction the fuel and air flow has to be reduced proportionately to maintain required combustion temperature. Current gas turbine design have several limitation on minimum allowable air flow to the combustor below a predetermined gas turbine load which impacts the fuel air ratio also the combustion temperature and increases the emission at lower gas turbine load. There is a desire therefore for methods to minimize the air flow to the combustor further as function of fuel flow at lower loads and extending gas turbine emissions compliance during periods of reduced loads.
[0005] Shape memory alloys (SMA), sometimes referred to as smart materials, have the ability to change shape based on microstructure and composition. SMAs take advantage of the transition of the microstructure from a low temperature martensitic structure to a high temperature austenitic structure (and back) in a predictable manner. The SMAs may provide the ability to regulate the airflow through boreplugs by opening, closing (or partially opening) the bore apertures thereby increasing or decreasing airflow. And while one well-known SMA, nitinol, or NiTi having roughly an equal atomic percentage of Ni and Ti, is unsuitable for use as a boreplug opening due to the high temperatures experienced in the operation in a gas turbine engine, other SMAs having the ability to survive high temperatures of operation as well as the corrosive, oxidative environment of a gas turbine engine may be suitable. Thus, a shape memory alloy suitable for use in the high temperature, oxidative and corrosive environment of a gas turbine engine may find use as a component for the regulation of cooling flow based on changing operational conditions.
SUMMARY OF THE INVENTION
[0006] A cooling arrangement for a gas turbine engine is set forth. The gas turbine engine comprises a compressor for compressing air, a combustor for combusting fuel with compressed air and a turbine for generating power. A discharge channel from the compressor directs compressed air from the compressor downstream for use in the combustor and for cooling hot sections of the engine such as portions of the combustor and the turbine. One of the cooling apparatus of the engine is a cooling channel that provides cooling for cooling flow to turbine buckets. Cooling air for the cooling channel is provided from the discharge channel. A compressor discharge case forms a boundary between the cooling channel and the discharge channel to prevent unrestricted flow of air between the cooling channel and the discharge channel. Flow between the discharge channel and the cooling channel is restricted by at least one aperture in the compressor discharge case, which provides communication between the flow of air through the discharge channel and the first cooling channel. A restrictor device within the at least one aperture further regulates the flow of air between the discharge channel and the cooling channel in response to a physical condition of the gas turbine engine. The restrictor device is positioned in the at least one aperture. The restrictor device deforms in response to at least one of a temperature of the air flowing through the discharge channel and a power output of the gas turbine engine, thereby regulating the opening for air flow through the at least one aperture.
[0007] The cooling arrangement comprises a flow of air through a discharge channel, a first cooling channel and at least one aperture or borehole through the compressor discharge case providing communication between the flow of air through the discharge channel and the first cooling channel. A restrictor device is placed within the at least one aperture to regulate the flow of air between the discharge channel and the first cooling channel. The restrictor device deforms in response to a physical condition of the gas turbine engine. The physical condition may be a temperature of the air flowing through the discharge channel, the temperature in or adjacent to the cooling channel reflective of the area to be cooled or a power output of the gas turbine engine. The deformation of the restrictor device in or across the borehole regulates the opening through the at least one aperture, which controls the air flow between the discharge channel and the first cooling channel.
[0008] The modulation of airflow by reducing the flow of air from the discharge channel and through the cooling channel when it is not needed will change the air pressure across bucket segments. This change in air pressure across the bucket shanks should assist in reducing cross shank leakage. In addition, by restricting the flow of air through cooling channels when it is not needed, more air will be available to support combustion to manage both CO and NO x levels, particularly during turndown. Control of CO and NO x are critical in controlling of emissions from gas turbines.
[0009] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cross-section of a gas turbine engine utilizing a compressor discharge case.
[0011] FIG. 2 is a cross section of a compressor discharge case showing the path for cooling air for the 1FWSP location.
[0012] FIG. 3 is a perspective view of the compressor discharge case of FIG. 2 having 18 boreplugs.
[0013] FIG. 4 depicts a cross section of a bore hole of FIG. 2 showing a SMA boreplug at two different temperatures.
[0014] FIG. 5 depicts a cross section of a bore hole of FIG. 2 showing a second embodiment of a SMA boreplug at two different temperatures.
[0015] FIG. 6 depicts the SMA operational envelope in a compressor casing.
[0016] FIG. 7 depicts the increase in CO with gas turbine turndown.
[0017] FIG. 8 represents the improvement due to reduction in CO emissions at 0° ambient temperature due to opening of three boreplugs.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention utilizes the unique properties of SMAs to provide cooling based on temperature. SMAs are characterized by temperature-dependent phase changes, the phases generally being a low temperature martensitic phase and an elevated austenitic phase. While SMAs can exhibit one-way shape memory, two way shape memory of SMAs makes cooling modulation possible. Two way shape memory is characterized by a shape transition both upon heating from the martensitic phase to the austenitic phase, as well as upon cooling from the austenitic phase to the martensitic phase. Two way shape memory may be either extrinsic or intrinsic. Intrinsic behavior is induced in SMAs through processing, which includes deformation of the SMA material while in the martensitic phase, followed by multiple heating and cooling cycles through the transformation temperature range under constraint. Once processing is complete, shape changes between the low temperature state and the high temperature state is reversible. Extrinsic behavior combines a SMA that exhibits one way behavior with another element that provides a restoring force that recovers the shape after the one way deformation.
[0019] Nitinol, Ni—Ti alloys having approximately equal atomic percentages of nickel and titanium, are well known SMAs. However, nitinol is not suitable in oxidizing, corrosive environments and the transformation temperatures of martensite to austenite is relatively low, the temperatures occurring over a range extending up to about 100° C. However, other suitable SMAs having higher temperature capabilities include alloys having compositions selected from the group consisting of Ni, Al, Nb, Ti, Ta and combinations thereof and platinum group metals selected from the group consisting of Pt, Pd, Rh, Ru, Ir and combinations thereof. More specifically, suitable shape memory alloy compositions may include nickel aluminum based alloys such as nickel aluminum alloys including a platinum group metal (PGM). Because the behavior of the SMA is very dependent on alloy composition, small changes in composition and/or processing can be used to alter transformation temperature, strain hysteresis, actuation force, yield strength, damping ability, resistance to oxidation, hot corrosion, ability to actuate through repeated cycles, capability to exhibit two way shape memory effect among other engineering attributes. More specifically, the SMA alloy compositions may include alloys having the formula (A 1−x PGM x ) 0.5+y B 0.5−y , where A is selected from the group consisting of Ni, Co, Fe and combinations thereof PGM is selected from the group consisting of Pt, Pd, Rh, Ru, Ir and combinations thereof and B is selected from the group consisting of Al, Cr, Hf, Zr, La, Y, Ce, Ti, Mo, W, Nb, Re, Ta, V and combinations thereof x is greater than 0, y is from 0 to about 0.23. The SMA alloy may additionally include up to about 1 atomic % of C or B.
[0020] Thus, it is clear that the behavior of SMAs is well-known, and the behavior of SMAs can be varied to achieve two way shape memory behavior by modifying the composition of the alloy to exhibit two way shape memory at various temperatures. Furthermore, the SMA alloy composition can be modified to also provide oxidation resistance and corrosion resistance.
[0021] Referring now to FIG. 1 , which is a cross section of a gas turbine engine 10 , depicting the fan portion 12 of the engine, the compressor portion 14 of the engine, the combustor portion 16 of the engine, the turbine portion 18 of the engine and the exhaust portion 20 of the engine. Air from the environment is inlet through fan portion 12 and directed to compressor portion 14 where it is compressed to high pressures, the temperature of the air also being elevated by the compression process. Compressed air from compressor portion is then used for combusting fuel, but also may be used for other purposes such as active or passive cooling of various components in the engine. Compressed air is mixed with fuel in combustor portion 16 where the fuel is ignited and burned. The hot gases of combustion, being energetic, travel at high velocity to turbine portion 18 , where energy is extracted the energy being converted to electrical energy or mechanical energy. A portion of the energy extracted by the turbine is utilized to turn compressor portion 14 and fan portion 12 . The less energetic exhaust gases are then exhausted through exhaust portion 20 as exhaust gases which may be treated before being returned to the environment.
[0022] FIG. 2 represents a cross-section of compressor portion 14 of gas turbine engine of FIG. 1 . Some compressor air is channeled through passageway 30 , where it cools rotor 32 and turbine blades 34 mounted on rotor 32 . The amount of cooling air required will depend on a number of factors, including ambient air temperature and the pressure of the compressor discharge air. Because ambient air temperature can vary significantly, depending upon the location of the gas turbine, by 110° F. or more, provisions are normally provided to increase cooling air volume at higher operating temperatures.
[0023] FIG. 2 shows the flow of compressor discharge air as it is funneled by compressor discharge case to the next stage of gas turbine 10 . Compressor discharge case includes a plurality of boreholes 40 . These boreholes 40 may be filled with boreplugs 42 . Prior art designs utilize boreplugs 42 to selectively fill boreholes 40 based on anticipated cooling flow requirements, each borehole providing additional cooling flow. The number of boreholes 40 with or without boreplugs 42 is dependent on the anticipated cooling flow requirements, more anticipated cooling requiring the removal of more boreplugs.
[0024] Cooling flow is channeled through boreholes 40 into second channel 44 where additional cooling air is permitted to flow to permit additional cooling to rotor 32 and to turbine blades 34 mounted on rotor 32 . Unlike the prior art, which anticipated cooling flow requirements at gas turbine installation or during maintenance, the design of FIG. 2 includes a plurality of boreholes 40 , each of boreholes 40 including a restrictor device positioned within borehole 40 to control the flow of air between the discharge panel and the first cooling channel. The restrictor device may be a boreplug 42 . FIG. 3 depicts such a casing showing 18 boreholes 40 , each with a boreplug 42 .
[0025] Boreplugs 42 of the present invention may be installed in all boreholes 40 or only in a predetermined number of boreholes 40 . The actual number of apertures or boreholes and boreplugs will depend on the gas turbine design. Boreplugs 42 comprise a shape memory alloy (SMA), the SMA selected based on its ability to respond to changes in temperature by change of shape due to changes in microstructure, for example, austenite to martensite and vice versa. By careful selection of composition and heat treatment, the SMA material can respond to changes in temperature. The selection of composition and heat treatment to obtain the requisite behavior is referred to as “training.” As the temperature of compressor discharge air changes, boreplugs 42 comprising SMA undergo a modification in shape, thereby increasing, reducing or stopping the flow of air through boreholes 40 . The ability of boreplugs 42 to change shape to increase or reduce the flow of air through boreholes based on an increase or decrease in temperature respectively means that the SMA exhibits bidirectional behavior, and the SMA is bidirectional. Typically, the SMA assumes a first shape in their martensitic condition. On reaching a predetermined temperature, depending upon alloy composition and heat treat condition, the SMA will convert to an austenitic condition. On transforming to its austenitic condition, the SMA assumes a different shape.
[0026] In a simple example, referring again to FIG. 3 as well as to FIGS. 4 and 5 , when ambient temperatures are low and pressure of compressor discharge air is also low, the temperature range of the compressor discharge air being known, there is no need for additional cooling air to flow through boreholes 40 into channel 44 . Within this temperature range, the SMA material comprising boreplugs 42 are selected so that boreholes 40 are closed by boreplugs 42 and remain closed within this temperature range. Thus, compressor flow can be directed through compressor discharge case without diversion into channel 44 , as additional cooling is not needed. As compressor discharge air increases, due to increased turbine demand and higher ambient temperatures, there is a need for increased air flow to cool the region referred to as first forward wheelspace (1FWSP), since air flowing in passageway 30 is inadequate. The increased temperature of the compressor discharge air flowing over boreplugs 42 , of course, raises the temperature of boreplugs 42 . The SMA material comprising the boreplugs are preselected to change shape as the temperature of the compressor discharge air reaches a predetermined temperature, the change in shape of the SMA material opening the boreholes 40 to allow compressor discharge air to pass through boreholes 40 and into channel 40 .
[0027] FIGS. 3-5 represent the broad embodiment of the present invention. There are a number of possible variations, all within this broad embodiment. Referring to FIG. 3 , which discloses 18 boreholes 40 , all of the boreplugs 42 in boreholes 40 may comprise the same SMA material composition, so that on reaching a predetermined temperature, all boreplugs change shape identically to change the flow of air from a minimum or zero to a maximum, resulting in maximum airflow through boreholes 40 into channel 44 to provide cooling to 1FWSP.
[0028] Alternatively, boreplugs 42 may comprise the same SMA material composition. However, boreplugs 42 may change shape over a range of temperatures, that is, boreplugs may convert from a martensitic condition to an austenitic condition over a range of temperatures. Thus, SMA material may be selected so that it moves a predetermined amount over a range of temperatures, so that the amount of air passing through boreholes 40 into channel 44 is modulated over the temperature range. This allows the amount of air admitted into channel 44 to increase as the temperature of the compressor discharge air is increased.
[0029] Because SMA materials are very sensitive to temperature, and can be trained to change shape on achieving a predetermined temperature. Yet another embodiment utilizes a different SMA material for boreplugs 42 in boreholes 40 . A plurality of boreplugs 42 of the same SMA material may be utilized in a plurality of boreholes 40 , as illustrated in FIG. 4 in which boreplug 42 is cylindrically shaped. It is within the scope of this invention to utilize a different SMA material composition for a boreplug 42 in each of boreholes 40 . Because SMA materials can be trained to change shape with changing temperature, different compositions or heat treat conditions of SMA materials can be selected for use in boreholes so that they change shape at different temperatures, i.e. convert from martensitic condition to austenitic condition at different temperatures. Thus, as the temperature changes in the discharge channel, various boreplug or boreplugs 42 will change shape to modulate air flow through boreholes into channel 44 as needed based on the discharge temperature. A boreplug 42 in individual boreholes may be further comprised of a plurality of segments 48 , as illustrated in FIG. 5 .
[0030] SMA materials can be trained to modulate airflow in a number of ways. Whatever method is used, the modulation should admit more air into channel 44 as additional cooling air is required in the cooling channel with increasing discharge channel air temperature. Thus, boreplug 42 may be in a deformed position at cooler temperatures, blocking borehole 40 , and may straighten into an undeformed position at a preselected temperature or temperature range, thereby increasing airflow through borehole 40 . Alternatively, boreplug 42 may be in an undeformed position at cooler temperatures, blocking borehole 40 , and may deform at a preselected temperature or temperature range, thereby increasing airflow through borehole 40 . FIGS. 4 and 5 illustrate a segmented boreplug 42 installed in borehole 40 , creating a varying area orifice for regulating cooling flow. In these Figures, segmented boreplug 42 is deformed at cooler temperatures, blocking airflow into borehole 40 . As shown in FIGS. 4 and 5 , at cooler temperatures, segmented boreplug 42 may be deformed to only partially block airflow through borehole 40 . However, it will be understood by those skilled in the art that segmented boreplug 42 may be deformed so as to substantially block borehole 40 . As the ambient temperature increases, the SMA material straightens into an undeformed position and occupies counterbore 46 in compressor discharge case 36 so that maximum airflow occurs through borehole 40 . As noted above, SMA material may be selected and trained so as to change shape at a preselected temperature or over a preselected temperature range. When selected to change shape over a preselected temperature range, the airflow through borehole 40 will be modulated as the temperature changes within the range. It also will be understood by those skilled in the art with a segmented boreplug 42 having a plurality of segments, each of the segments may be comprised of a different SMA material composition that changes shape at a different preselected temperature, so that each boreplug 42 is self-modulating as temperature changes.
[0031] By modulating boreplug flow as a function of temperature, reduction in the amount of air passing into channel 44 will reduce air leakage across the blade shank when air flow into channel 40 is reduced by the shape memory alloys as cooling demands decrease. Modulating secondary airflows may impact air available to the combustor. Unlike the prior art schemes in which airflow was determined on installation, the flow of air for cooling in the present invention is determined modulated by the use of shape memory alloys. Thus, except under those operating conditions in which maximum cooling is required, under most conditions, more air should be available to the combustor which should provide additional flexibility to adjust combustion conditions to further manage NO x , un unexpected additional benefit of air modulation as more air can be provided for control of combustion at part load conditions.
[0032] SMA materials, either as a cylindrical plug or as cylindrical segments may be attached to compressor discharge case 36 by brazing, welding or other joining technique. It also may be possible to mechanically lock plug 42 to compressor discharge case, such as by a dovetail arrangement or other keyway/keyhole arrangement that positively locks plug 42 to compressor discharge case 36 . The selected technique should not affect the temperature behavior characteristics of the SMA material.
[0033] In another embodiment, installed boreplug 42 is installed in counterbore 46 so that little or no air can pass through boreholes 40 . As temperature is increased, boreplug 42 undergoes a shape change so that air can pass around boreplug 42 , through counterbore 46 , into and through borehole 40 and into channel 44 . The operation of boreplug 42 in this embodiment once again depends on the shape change characteristics of the SMA with temperature, although the flow path of the cooling air through compressor discharge case, and further illustrates the various ways in which the SMA material can be used to modulate or regulate the flow of air to provide additional cooling as needed as a result of part/full load conditions, ambient air temperature etc.
[0034] While the present invention has been described in terms of circular or cylindrical apertures or boreholes 40 , and boreplugs 42 having a circular area profile matched to boreholes to provide the desired airflow based on load conditions and/or ambient air conditions, it will be recognized by those skilled in the art that the shape of boreholes and boreplugs is not so restricted, and any geometric shape, including but not limited to rectangular, square, triangular, oval, hexagonal octangular etc. may be used.
[0035] FIG. 6 depicts load as a function of compressor discharge temperature as well as ambient temperature using active cooling such as the active boreplugs of the present invention. Ambient temperature alone may affect compressor discharge temperature at 1FWSP (where this designates the temperature of the compressor air as it is discharged from the compressor) by a ΔT 1 which is more than 100° F., and gas turbine load combined with ambient temperature can affect compressor discharge temperature at 1FWSP by ΔT 3 which is more than 200° F. FIG. 6 thus shows the importance of providing additional cooling to 1FWSP, as without such cooling, temperatures could easily exceed 1000° F.
[0036] In still another embodiment, SMA material can be used to control cross shank leakage.
[0037] In yet another embodiment, SMA material can be used in boreplugs to improve the turndown capability of a gas turbine engine. At lower load levels during turndown, the amount of fuel consumed is decreased and the amount of air provided for combustion also changes, to maintain the emissions from combustion, specifically NO x and CO, within prescribed, compliance limits. As the ambient temperature falls, the compressor discharge temperature also decreases, which may adversely affect emissions, and the minimum load for CO compliance rises steeply, the ambient air temperature being directly related to the compressor discharge temperature of the air. This is shown in FIG. 7 which is a plot of CO vs. combustion temperature. However, emissions can be improved by modulating the flow of compressor discharge air through boreholes 40 using SMA boreplugs 42 . At high compressor discharge temperatures, which occur at high ambient temperatures, the SMA boreplug may be provided in a heat treatment condition such that the bore opening is smaller. At low compressor discharge temperatures, which occur at low ambient temperatures, the SMA boreplug, due to its heat treatment condition, reacts to the low temperature, by providing an enlarged bore opening. This results in a reduction of air flow to the combustor and an increase in the cooling flow air based on the compressor discharge temperature, which is related to the ambient temperature. So for example, boreplugs may be completely closed or partially closed at a high compressor discharge temperature, for example about 750° F., and may be completely open at a low compressor discharge temperature, for example about 620° F. The SMA boreplugs may also undergo a gradual change in the opening as the temperature varies between the extremes. Thus, boreplugs 42 may be completely closed at 750° F., completely open at 620° F. and open to bypass about 50% of air midway between these extreme temperatures. Alternatively, boreplugs 42 may completely open to bypass maximum air when a predetermined temperature is reached, for example 650° F. The operation of the boreplugs 42 in this manner has been found to reduce the minimum emission compliant load by up to 3% at 0° F. ambient as indicated in FIG. 8 . FIG. 8 represents the measured reduction in gas turbine turndown capability of 3% at 0° F. (ambient temperature). This reduction means the gas turbine can run with an emission compliant load of 37% rather than 40% load with a few (3 boreplugs) in the open configuration.
[0038] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | A cooling arrangement for a gas turbine engine. The cooling arrangement comprises a discharge channel for air flow from a compressor, a first cooling channel and at least one aperture providing communication between the flow of air through the discharge channel and the first cooling channel. A restrictor device in the aperture regulates the flow of air between the discharge channel and the first cooling channel. The restrictor device deforms to vary air flowing through the aperture in response to a physical condition of the engine. This physical condition of the engine may be that of the temperature of air flowing through the discharge channel, the restrictor device responding to regulate the flow of air based on that temperature. The restrictor device may be a two-way shape memory alloy. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/271,148 filed Nov. 14, 2008, the teachings of which are incorporated herein by reference.
FIELD
The present disclosure relates to vehicle floor coverings, and more particularly to a three piece system for retaining a floor mat to a floor carpet.
BACKGROUND
It is often desirable to place a floor mat on top of the carpet within a vehicle in order to keep the vehicle carpet clean and to reduce wear and tear thereof. Unfortunately, floor mats may be subjected to twisting motions from the entrance and exit of vehicle occupants which can cause slippage. Such slippage may lead to injury of an occupant when entering or exiting from a vehicle. In addition, a floor mat may slip over a vehicle carpet so as to become jammed under the accelerator, brake, or clutch pedals of the vehicle preventing proper operation thereof which may present a possibly dangerous condition.
A number of solutions have been proposed in the prior art to solve the problem of mat or rug slippage along a surface. These solutions can generally be divided among devices which hold the rug, mat, or carpet relative to an underlying floor and those which hold a rug or mat relative to an underlying carpet. In one instance, the floor mat may be sewn to the floor carpet, making it non-removable for cleaning. In another instance, a fastener was attached to the floor pan of the car and passed through holes in the carpet and mat to locate them. Attaching fasteners to the floor pan generally may cause problems with moisture leakage where the fastener is attached. Such fasteners may include an escutcheon to cover the end of the fastener which protrudes through the carpet.
Further, the floors of some vehicles, such as pick-up trucks, may be flat so that contoured mats may not be used. In some cases, two-sided tape may be used to secure a floor mat from slipping or the mat may include a retention system which is connected to the door sill.
SUMMARY
In a first aspect, the present disclosure is directed at a fastening system for attaching two layers together, comprising a first component including a base portion, a foldable arm, and a receiving portion to mechanically engage the foldable arm, and a projection to engage a second component. The second component includes a platform portion having a protrusion configured to mechanically engage with a third component. The third component includes a platform having a central opening, the opening configured to mechanically engage with the protrusion of the second component.
In a second aspect, the present disclosure is directed at a method of attaching two layers together comprising providing a fastener having three components, a first component including a base portion, a foldable arm, and a receiving portion to mechanically engage said foldable arm, and a projection to engage a second component. The second component includes a platform portion having a protrusion having an opening to engage the first component and the protrusion is configured to mechanically engage with a third component. The third component includes a platform having a central opening, the opening configured to mechanically engage with the protrusion of the second component. A first and a second layer may be provided, wherein the first layer includes openings to accommodate both the foldable arm as well as the receiving portion configured to ultimately mechanically engage with the foldable arm, wherein the second layer includes an opening for the protrusion.
One may then insert the foldable arm and the receiving portion through the openings in the first layer followed by folding of the arm such that it is mechanically engages with the receiving portion. This may then be followed by engaging the second component to the first component by inserting the projection into the opening in the second component and inserting the protrusion through the opening in the second layer and mechanically engaging the opening of the third component to the protrusion of the second component and securing the second layer to the first layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain principles of the invention.
FIG. 1 is a perspective view of the three piece floor mat retention system in an exploded configuration showing the individual components; and
FIG. 2 is a perspective view of the three piece floor mat retention system in an installed position attaching a floor mat to a carpet.
DETAILED DESCRIPTION
The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
As shown in FIG. 1 , the snap retention system 10 of the present disclosure comprises three components, a first component 20 which includes a base portion 21 , a foldable arm 22 and a receiving portion 26 . The foldable arm 22 further may include a serrated portion 28 for engaging the backside of the carpet, a living hinge 29 and a connector portion 24 including an opening 25 . In addition, the first component includes a projection 27 for engaging a second component 30 in mechanical engagement, such as a snap fit.
A second component 30 provides a platform 31 , such as in the form of a round disc, having a protrusion 32 which may include a loop 33 and a plurality of molded detents 34 which extend into an opening and are spaced apart to interface with projection 27 in a mechanical type relationship (e.g. a snap-fit relationship) to engage the first component 20 and the second component 30 together. That is, the loop 33 may extend between the detents and is ultimately configured to be under tension when engaged with the edges of the projection 27 . It may therefore be appreciated that any form of mechanical engagement of the second component with the first component is contemplated herein, such as a friction and/or threaded type engagement.
The connection of the first component to the second component may then allow for retaining a floor mat between the second component 30 and a third component 40 (see FIG. 2 ) while the third component 40 provides retention of the mat to the carpet. The second component 30 may also include an external threaded portion on the protrusion 32 which may engage an internal threaded portion 42 of the third component 40 . The third component may therefore provide a platform 41 which may also be in the shape of a round disc. It may also be appreciated that any form of mechanical engagement of the second component to the third component is contemplated herein, such as the above described threaded engagement and/or snap-fitting methods.
To install the retention system 10 , two slots, not shown, may be cut into a carpet 50 and the receiving portion 26 and foldable arm 22 may be passed through the slots and the arm folded beneath the carpet around living hinge 29 , such that the opening 25 in the connector portion 24 engages the receiving portion 26 and retains the first component 20 to the carpet 50 . See FIG. 2 . The receiving portion may therefore be understood as any feature (e.g. a hook) that may provide mechanical engagement to a foldable arm, which mechanical engagement may proceed via use of a connector portion 24 configured on the end of the foldable arm.
This then secures the first component 20 to the carpet 50 . The serrated portion 28 of the foldable arm 22 may be designed, according to the thickness of the carpet and the length of the portion of the foldable arm above its hinge point, to penetrate a desired amount into the backside of the carpet. This may then provide additional stability for the connector when attached to a floor mat.
Next, the second component 30 may be snap-fit to the first component 20 by pressing the second component 30 over the projection 27 and engaging the projection with the molded detents 34 and loop 33 inside the opening in the second component 30 .
Next, a floor mat 60 having a hole (not shown) to accommodate the protrusion 32 may be provided and slipped over the protrusion. This may be followed by threading the third component 40 via the internal threads 42 and external threads 36 on to the second component 30 securing the floor mat to the carpet. The third component 40 may include designs, logos, etc. on the top surface to provide aesthetics, as it is exposed to view.
The three components 20 , 30 and 40 may generally be molded of a thermoplastic or thermoset (crosslinked) material. For example, suitable thermoplastics may include polyethylene and/or polypropylene. In the case of polypropylene, such may provide for the preferred formation of the living hinge noted above, but it may be appreciated that the hinge may be made of materials other than polypropylene. Reference to living hinge may be understood as a hinge that may be repeatedly flexed without failure. Continuing, other suitable thermoplastics may include polyamides (e.g., nylon-6,6 or nylon-6), ABS, polystyrene, high-impact polystyrene, thermoplastic olefins (TPO), polycarbonate (PC), poly(ethylene terephthalate), poly(butylene terephthalate), polysulfones, etc. One may also utilize elastomeric materials, e.g., thermoplastic polyester elastomers and/or polyurethane elastomers, etc. With respect to thermosets, one may consider the use of epoxy resins, phenolic resins, and/or crosslinked polyurethane systems.
While the connector described herein may be of nearly any practical size, generally it may be about 1 inch in diameter. It is also contemplated that the connector may have a diameter (largest cross-sectional linear dimension) of about 1.0 inch to 6.0 inches. The three piece floor mat snap retention system 10 as described herein may therefore provide a relatively simple and cost effective solution to stabilize a floor mat on a selected surface, such as a carpeted surface in a vehicle.
The description and drawings illustratively set forth the presently preferred invention embodiments. The description and drawings are intended to describe these embodiments and not to limit the scope of the invention. Those skilled in the art will appreciate that still other modifications and variations of the present invention are possible in light of the above teaching while remaining within the scope of the following claims. Therefore, within the scope of the claims, one may practice the invention otherwise than as the description and drawings specifically show and describe. | A three piece fastener is provided for attaching two layers, e.g. a floor mat for a vehicle to a floor carpet which may then stabilize the mat relative to the carpeting. The three components may connect together through a combination of mechanical connections to provide a relatively simple and cost effective solution to floor mat retention. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent Application No. 102015016517.8, filed Dec. 19, 2015, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure pertains to a method of determining the position of an RFID transponder and a motor vehicle.
BACKGROUND
[0003] Reading devices or readers and an RFID transponder form a transmitter-receiver system for the identification and localization of objects which are attached to the RFID transponder. An RFID system thus includes an RFID transponder and a reader. RFID systems are used in a wide variety of technical solutions. For example, they are used in retail outlets on cash tills for identifying products to be paid for, or in logistics and in warehouses for the correct recording of incoming and outgoing goods, as well as for inventories and the retrieval of objects. Additional, they can also be used for identifying persons or also for identifying motor vehicles.
[0004] In motor vehicles, RFID systems are also deployed for the wireless, radio-based unlocking of doors of the vehicle and for the wireless, radio-base starting of a drive motor of the vehicle. If the corresponding RFID transponder is located within the transmission range of the reading device or reader, automatic starting or start/drive clearance of the drive motor or automatic unlocking of the vehicle doors takes place. The unlocking or starting takes place if the key with the corresponding RFID transponder is located within the transmission range of the reading device or reader. However, by amplification or a transmission system (data transmission system) of the transmission signal emitted by the reader, the key with the corresponding RFID transponder can also be inadvertently or unintentionally activated by thieves. If, for example, the key with the RFID transponder is in a house and the motor vehicle is in parking area in front of the house, through this amplification/transmission, the motor vehicle can be unlocked and started even though the RFID transponder is in the possession of the owner of the vehicle. Through this theft of the vehicle is possible.
[0005] U.S. Pat. No. 7,903,022 B2 describes a device for determining a distance between a transmitter and a receiver is known. The distance is determined by a phase change between a first signal and a second signal.
SUMMARY
[0006] In accordance with the the present disclosure, a method is provided to determine the position of an RFID transponder and a motor vehicle in which the position can be reliably and precisely determined with little technical outlay. In an embodiment, the method of determining the position of an RFID transponder includes separate emission of at least two electromagnetic alternating fields from at least two antenna to one RFID transponder. The antenna are at a distance from each other so that the two electromagnetic alternating fields are emitted at a distance from one another. Reflection of the emitted electromagnetic alternating fields to the one RFID transponder so that the reflected electromagnetic alternating fields are sent back to the antenna. The transit times of the electromagnetic alternating fields are determined from emission to receiving back at antenna. A determination of the distances between the antenna and the RFID transponder are determined. The position of the RFID transponder is determined from the distances relative to the antenna.
[0007] The electromagnetic alternating field is is made up, for example, of radio waves or light, for instance infrared light. Sound is preferably also subsumed under the term electromagnetic alternating field. The propagation speed of the electromagnetic alternating field is known so that from the transit time of the electromagnetic alternating field from emission to being received back the distance of each antenna to the respective RFID transponder can be determined. On the basis of the determined distances, the position of the RFID transponder with regard to the two antenna can be determined. Preferably the separate emission of the electromagnetic alternating fields from the different antenna takes place at the same time and the electromagnetic alternating fields are differentiated, for example, by way of a different frequency of the at least two emitted electromagnetic alternating fields. Preferably the electromagnetic alternating fields are reflected simultaneously on the RFID transponder.
[0008] In an additional embodiment, with two antenna the position of the RFID transponder is determined two-dimensionally from the at least two distances relative to the at least two antenna. With two antenna, the position of the RFID transponder can be determined two-dimensionally. For this a corresponding notional plane relating to the two antenna is assumed so that resulting therefrom the two-dimensional position of the RFID transponder can be determined.
[0009] In an additional variant the position of the RFID transponder is determined three-dimensionally with at least three antenna from the at least two distances relative to the at least three antenna. With three antenna, the position of the RFID transponder can be determined three-dimensionally relative to the at least three antenna.
[0010] In an additional embodiment the at least two antenna are part of at least one reader. The at least two antenna for emitting and receiving the electromagnetic alternating field are part of a reader or reading device.
[0011] In a further embodiment, determination of the position of the RFID transponder from the at least two distances relative to the at least two antenna is carried out repeatedly at a time interval so that a movement and/or speed of movement and/or a direction of movement of the RFID transponder is determined from the determined positions.
[0012] In an additional embodiment, the emitted at least two electromagnetic alternating fields are reflected on one, more particularly only one identical, antenna of the RFID transponder. The RFID transponder includes an antenna and the electromagnetic alternating fields emitted by the antenna of the at least one reader are reflected on the antenna of the RFID transponder.
[0013] In an additional embodiment, in order to activate the reflection properties of the antenna of the RFID transponder, an electromagnetic alternating field is emitted from at last one antenna of the at least one reader, the reflection properties of the antenna of the RFID transponder are then activated so that at least two electromagnetic alternating fields are reflected on the antenna of the RFID transponder. Only after receiving the electromagnetic activation alternating field is the reflection property of the antenna of the RFID transponder activated by a microchip of the RFID transponder so that through this the electromagnetic alternating fields emitted by the at least two antenna of the at least one reader are reflected on the antenna of the RFID transponder. The electromagnetic activation field and the electromagnetic alternating field can also be emitted at the same time.
[0014] In an additional variant, in order to determine the at least two transit times of the at least two electromagnetic alternating fields from emission to being received back at the at least two antenna, the emitted electromagnetic alternating fields are modified and the at least two transit times are determined from the respective time differences from the start of emission of the respective modified electromagnetic alternating field to receiving back the modified electromagnetic alternating fields
[0015] In an additional variant the emitted electromagnetic alternating fields are modified in that each x th wave has a different amplitude from the other waves outside the x th wave and/or the frequency of which is changed and/or a phase shift is carried out and/or switching off of the emitted at least one electromagnetic alternating field is carried out and/or switching on of the emitted electromagnetic alternating field is carried out, and/or a direct digital frequency synthesis is carried out.
[0016] Expediently, the received back changed electromagnetic alternating fields are differentiated by at least one reader from unmodified electromagnetic alternating fields.
[0017] In an additional variant, the emitted electromagnetic alternating fields and/or activation alternating fields are cryptographically secured. The electromagnetic alternating fields and/or the activation alternating fields are thus cryptographically secured so that unauthorised third parties cannot transmit equivalent electromagnetic alternating fields and/or activation alternating fields to the RFID transponder corresponding to the effect of the cryptographically-secured electromagnetic alternating fields and/or activation alternating fields on the RFID transponder.
[0018] In an additional variant the position of several RFID transponders is determined and the RFID transponders are differentiated with a transmitted identification code. To determine the position of several RFID transponders these can be differentiated with a corresponding identification code which is transmitted by the RFID transponder.
[0019] In a further embodiment different electromagnetic alternating fields are emitted by different antenna of the at least one reader and the transit time of each electromagnetic alternating field from emission to receiving back at an identical antenna of the at least one reader is determined, wherein the emission of the different electromagnetic alternating fields preferably takes place at the same time. The different electromagnetic alternating fields differ, for example, through a different frequency and/or a different amplitude and/or other amplitudes at each x th wave of the electromagnetic alternating fields as waves.
[0020] In an additional embodiment the received back, different, preferably modified electromagnetic alternating fields emitted by different antenna of the at least one reader, are differentiated by the at least one reader and in each case one different electromagnetic alternating field is only recorded by that reader from which it was emitted. As in each case the distance between a reader and the RFID transponder is to be determined, it is necessary that the received back different electromagnetic alternating fields can be assigned to the reader with the antenna from which these electromagnetic alternating fields were emitted. This is necessary so that in each case the distance between only one antenna of the reader and the RFID transponder can be determined.
[0021] The present disclosure also includes a computer program with program coding which are stored on a computer-readable data carrier in order to implement a method described in this patent application when the computer program is stored on a computer or a corresponding processing unit. Forming part of the present disclosure is also a computer program product with program coding means which are stored on a computer-readable data carrier in order to implement a method described in this patent application when the computer program is stored on a computer or a corresponding processing unit.
[0022] System according to the present disclosure with a motor vehicle and an RFID transponder, the motor vehicle including a vehicle body, at least one drive motor, more particularly an internal combustion engine and/or electric motor, an interior space for accommodating persons which is enclosed by the vehicle body, at least two antenna which are built into the motor vehicle, wherein a method described in this patent application is implementable preferably for determining the position of the RFID transponder from the at least two distances relative to the motor vehicle.
[0023] In an additional embodiment the motor vehicle includes at least two reading devices and one antenna is built into each reading device.
[0024] In an additional embodiment the RFID transponder is an RFID transponder for unlocking at least one door of the motor vehicle and the at least one door is only unlockable if the RFID transponder is located relative to the motor vehicle on the basis of the determined position of the RFID transponder within an area of a notional plane in the case of two-dimensional determination or a space in the case of three-dimensional determination and/or the RFID transponder is an RFID transponder for starting or clearing the starting of the at least one drive motor and the at least one drive motor can only be started if the RFID transponder is located relative to the vehicle on the basis of the determined position of the RFID transponder within an area of a notional plane in the case of two-dimensional determination or a space, in particular the interior space of the motor vehicle delimited by the vehicle body in the case of three-dimensional determination.
[0025] In a further embodiment the RFID transponder is attached to a motor vehicle and to determine the position of the motor vehicle, the method described in the patent application is implemented, for example in a multi-level car park or on an access road with a barrier or access-restriction device.
[0026] In a further embodiment the at least one RFID transponder is attached in each case to a component or a part of a motor vehicle and for determining the position of the at least one component or at least one part during the manufacturing of the motor vehicle the method described in this patent application is implemented. The manufacturing and assembly of the motor vehicle can thus be significantly improved.
[0027] In a further variant the at least one RFID transponder is attached in each case to a component or a part in a logistics centre and/or store and for determining the position of the at least one component or the at least one part in the logistics centre or the store the method described in this patent application is implemented.
[0028] In a further embodiment the at least one RFID transponder is attached in each case to an object or a part and for determining the position of the at least one object or at the least one part method described in this patent application is implemented.
[0029] In a further embodiment the system includes a central processing unit and/or the at least one reader includes a processing unit or a microcontroller for controlling and/or regulating and/or or implementing the method and preferably the processing unit includes a computer program or software and/or a computer program product and/or a data memory with software for implementing a method described in this patent application.
[0030] Expediently, the reading device or the reader includes an antenna, a device for generating an electromagnetic alternating field with the antenna, a device for recording an electromagnetic alternating field received with antenna, preferably a processing unit, preferably an energy supply, for example a power line or battery.
[0031] In a further embodiment the RFID transponder includes a microchip, an antenna, for example in the form of a coil, strip conductor in the case of a dipole antenna or slot antenna, preferably a carrier or a housing, preferably a power source, for example a battery. The RFID transponder is a passive RFID transponder or an active RFID transponder with an energy source, more particularly a battery.
[0032] Preferably the distance between the two antenna of the at least one reader is greater than 5 cm, 10 cm, 30 cm, 50 cm or 100 cm and/or less than 25 m, 10 m or 2 m.
[0033] In a further embodiment a reader includes one antenna or more antenna.
[0034] In a further embodiment the RFID transponder is built into an accessory component, for example a reading lamp, a searchlight, a floor light, and the accessory component can be switched on or off in the event that the RFID transponder is located, relative to the motor vehicle on the basis of the determined position of the transponder, within an area of a notional plane in the case of two-dimensional determination or a space, more particularly a part of the internal space of the motor vehicle delimited by the vehicle body, in the case of three-dimensional determination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements.
[0036] FIG. 1 shows a side view of a motor vehicle;
[0037] FIG. 2 shows a greatly simplified view of three reading devices, an RFID transponder; and
[0038] FIG. 3 shows as flow chart of the method of determining the position of the RFID transponder.
DETAILED DESCRIPTION
[0039] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description.
[0040] A motor vehicle 1 ( FIG. 1 ) has an interior space 8 and arranged within the interior space 8 are two front seats 9 and several rear seats 10 for accommodating passengers of the motor vehicle 1 . The motor vehicle 1 is driven by a drive motor 5 , namely an internal combustion engine 6 and/or an electric motor 7 . The interior space 8 is defined or enclosed by a vehicle body 2 of the motor vehicle 1 made, for example, of metal, in particular steel and/or aluminium, and/or of plastic, and an upper end area of the interior space 8 is delimited by a roof lining 3 . The view to the outside from the interior space 8 to the outside is provided by a windscreen 4 .
[0041] Three readers or reading devices 11 , 12 , 13 are built into the motor vehicle 1 , namely a first reader 11 , a second reader 12 and a third reader 13 . Each of the readers 11 , 12 , 13 includes an antenna 14 and a device 15 for generating an electromagnetic alternating field with the antenna 14 and a device 15 for recording an electromagnetic alternating field received with antenna 14 . An RFID transponder 16 includes an antenna 17 , a microchip 18 and a carrier 19 or a housing 19 . The RFID transponder 16 is built into a radio-based, non-mechanical key for unlocking and starting the motor vehicle 1 . The three readers 11 , 12 , 13 are attached to or integrated into the motor vehicle 1 at a distance from one another. The three readers 11 , 12 , 13 are connected to a central processing unit 20 with corresponding data and power lines (not shown). Energy is supplied to the three readers 11 , 12 , 13 by power lines, which are not shown, from the on-board network of the motor vehicle 1 . The processing unit 20 can also be arranged in a reader 11 , 12 , 13 (not shown).
[0042] The motor vehicle 1 , the three readers 11 , 12 , 13 and the RFID transponder 16 thus form a system 30 and with the system 30 , the position of the RFID transponder 16 relative to the motor vehicle 1 can be determined. From one reader 11 , 12 , 13 , i.e. an antenna 14 of the reader 11 , 12 , 13 , emission 21 of the electromagnetic activation alternating field initially takes place. The electromagnetic activation alternating field is received by the antenna 1 of the RFID transponder 16 so that as a result of this, by the microchip 18 of the RFID transponder 16 activation of the reflection properties of the antenna 17 of the RFID transponder 16 is carried out. Before, during and after the start of emission 21 of the electromagnetic activation field, emission 23 of three different electromagnetic alternating fields from the three antenna 14 of the three readers 11 , 12 , 13 takes place. The different electromagnetic alternating fields which are emitted from the antenna 14 of the readers 11 , 12 , 13 , are each assigned to one reader 11 , this means that a first electromagnetic alternating field is emitted by the first reader 11 , a second electromagnetic alternating field is emitted by the second reader 12 , and a third electromagnetic alternating field is emitted by the third reader 13 , in each case from the antenna 14 . These three different electromagnetic alternating fields can be differentiated,
[0043] As of or after the start of activation 22 of the reflection properties of the antenna 17 of the RFID transponder 16 , modification 24 of the emitted different electromagnetic alternating fields takes place. The activation 22 of the reflection properties 17 of the RFID transponder 16 is, for example, a result of a request to the RFID transponder 16 to supply data in a wireless or radio-based manner by emitting a corresponding electromagnetic alternating field from the antenna 17 of the RFID transponder 16 . The modification 24 is for example carried out as a marking of the three emitted different electromagnetic alternating fields, in that the amplitude of every third, fifth or seventh wave of the electromagnetic alternating field is modified, for example the amplitude of every third, fifth or seventh wave is increased. The emitted different electromagnetic alternating fields are reflected on the antenna 17 of the RFID transponder 16 , i.e. reflection 25 of the different modified electromagnetic alternating fields takes place at the antenna 17 . After reflection 25 , the emitted different modified electromagnetic alternating fields are received back 26 at the antenna 14 of the readers 11 , 12 , 13 . The electromagnetic alternating fields received back at the antenna 14 of the readers 11 , 12 , 13 can be differentiated by the readers 11 , 12 , 13 so that recording of the first electromagnetic alternating field which is carried out by the first reader 11 is exclusively carried out on the first reader and in an analogue manner the recording of the second electromagnetic alternating field is exclusively carried out on the second reader 12 and the recording of the third electromagnetic alternating field is exclusively carried out in the third reader 13 . In this way, in each case determination 27 of the transit time from the start of emission of the modified electromagnetic alternating field can be carried out by one reader 11 , 12 , 13 until it is received back at the the corresponding reader 11 , 12 , 13 . As the propagation speed of the electromagnetic alternating field is known, through this a determination 28 of the distances from one reader 11 , 12 , 13 or antenna 14 of a reader 11 , 12 , 13 to the RFID transponder 16 can be carried out.
[0044] With the central processing unit 20 , determination 29 of the position of the RFID transponder 16 relative to the motor vehicle then takes place. If the RFID transponder 16 is located in a spatial area around the motor vehicle with a distance of less than 5 metres, unlocking of the door of the motor vehicle 1 takes place. If the RFID transponder 16 is located within the interior space 8 of the motor vehicle 1 , automatic starting or clearance to start the at least one drive motor 5 takes place. In the event of clearance to start operation of an operating element, for example, a button, is also required for starting. The electromagnetic activation field and/or the electromagnetic alternating field can have a differing frequency, for example as long wave in the range between 125 kHz and 825 kHz, as short wave at around 14 MHz or as VHF between 860 MHz and 1000 MHz.
[0045] Seen overall, significant advantages are associated with the method according to the present disclosure of determining the position of the RFID transponder 16 and the system 30 according to the present disclosure. By way of the method according to the present disclosure the position of the RFID transponder can be simply and reliably determined. By way of the RFID transponder 16 the position of a motor vehicle 1 can also be determined in parking systems. With the arrangement of an RFID transponder 16 in the motor vehicle 1 the position of the motor vehicle 1 can also be determined, for example in front of associated barriers. The radio-based key with an RFID transponder 16 can be determined in the position relative to the motor vehicle 1 so that in this way unlocking of the door of the motor vehicle 1 and automatic starting of the drive motor 5 can be reliably and automatically carried out as a function of the position of the RFID transponder 16 or radio-based key relative to the motor vehicle 1 . Third parties cannot therefore bring about the manipulated unlocking of the door and starting of the drive motor 5 through amplification of the emission output of the reader 11 , 12 , 13 .
[0046] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents. | A method is disclosed for determining the position of an RFID transponder. Separate signals of at least two electromagnetic alternating fields are emitted from at least two antenna to one RFID transponder. The antenna are spaced at a distance from each other so that the two electromagnetic alternating fields are emitted at a distance from one another. The emitted electromagnetic alternating fields to the one RFID transponder are reflected so that the reflected electromagnetic alternating fields are sent back to the antenna. The transit times of the electromagnetic alternating fields are determined from emission to receiving back at the antenna. The distances between the antenna and the RFID transponder are determined, and the position of the RFID transponder from the at least two distances is determined relative to the at least two antenna. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a control system for a vane type variable displacement pump.
The prior art contains a control device for a vane type variable displacement pump, such as that shown in FIG. 1. A cam ring 1 of a vane type pump is pivotally mounted at a protrusion thereof to a support member of the pump by a pin 2, which serves as a fulcrum. Provided radially inward of the cam ring 1 is a rotor 4 having a plurality of vanes 3 which are slidable through the rotor 4 in a radial direction. The opposed faces of each pair of adjacent vanes 3 define, along the arc of the radial outward surface of the rotor 4 and the interior surface of cam ring 1 which the pair of vanes intersect, chambers which rotate and change in volume depending on angular position. The cam ring 1 is arranged in a variable eccentric relationship with the rotor 4. The cam ring 1 also has a lever 1a which is integrally formed on and extends from the cam ring 1 to receive a force due to a spring 5 and a force due to a piston rod 6a of a hydraulic cylinder 6 acting oppositely on the lever 1 a, so that the balance of both forces determines the amount of eccentricity of the cam ring. In FIG. 1, the rotor 4 rotates in a clockwise direction, so that hydraulic fluid is drawn from a reservoir 7 by a suction port 1b through an oil line 8, and the pressurized hydraulic fluid is delivered from a delivery port 1c to an oil line 9. The pressurized hydraulic fluid at the oil line 9 is regulated to a predetermined pressure (line pressure) by a control valve 10, and is delivered to hydraulic equipment, such as a clutch, which is not shown. The oil line 9 is also leads to a regulator valve 11. The regulator valve 11 acts to apply the line pressure to a hydraulic cylinder 6 through an oil line 12 when the line pressure in the oil line 9 is higher than a preset pressure, and to exhaust the hydraulic fluid from the hydraulic cylinder 6 to the reservoir 7 when the line pressure is below the preset pressure. With such a construction, when a rotating speed of the rotor 4 is low, substantially no hydraulic pressure is supplied to the hydraulic cylinder 6 so that the bias force of the spring 5 encounters substantially no resistance from the piston rod 6a and the amount of the eccentricity becomes maximum, whereas when the rotating speed of the rotor is high, the line pressure is supplied to the hydraulic cylinder 6 and the amount of the eccentricity becomes small. In this manner the amount of delivery at a low rotating speed can be assured while energy loss at a high rotating speed can be reduced.
However, in a control device for such a prior art vane type variable displacement pump as described above, problems exist such as follows. Namely, since a hydraulic cylinder has to be used to control the amount of the eccentricity of the cam ring in the control device, a large number of parts are required, and thus its cost becomes high and moreover, a large space is required.
SUMMARY OF THE PRESENT INVENTION
Accordingly, it is the primary object of the present invention to eliminate these problems of a prior art control device for a vane type variable displacement pump which have been already described.
Another object of this invention is to provide an inexpensive control device for a vane type variable displacement pump by eliminating the need of a hydraulic cylinder to control the eccentricity of a rotor therein.
This is accomplished by allowing or preventing communication between a first chamber at an angular position on the high-pressure side of the pump and a second chamber an the low-pressure (section) side of the pump through utilization of a regulator valve. The regulator valve is operated by a pilot pressure which is led from the delivery side of the pump. The eccentricity of the cam ring of the pump is determined by a pressure difference between the first chamber and second chamber portion. A spring is also provided to always force the cam ring in the direction which produces a larger eccentricity of the cam ring.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings, in which
FIG. 1 is a schematic view of a prior art control device for a vane type variable displacement pump; and
FIG. 2 is a schematic view a control device for a vane type variable displacement pump according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following, a detailed description of the present invention will be made with reference to FIG. 2 which shows an embodiment of the present invention.
Firstly, the construction of a pump incorporating a control device according to the present invention will be described.
A cam ring 21 is pivotally mounted at a protrusion thereof to a support member of the pump by a pin 22, which acts is its fulcrum. Provided radially inward of the cam ring 21 is a rotor 24 having vanes 23 which are slidable through the rotor 24 in a radial direction. Each pair of adjacent vanes defines therebetween, with the rotor and cam ring, a chamber. The cam ring 21 also has a lever 21a which is integrally formed on and extends radially from the outer periphery of the cam ring 21 to receive a force due to a biasing means such as a spring 25. The cam ring 21 is inclined to turn in a clockwise direction by the bias force of the spring to the lever 21a. Thus, the spring 25 and the lever 21a form a positioning means to pivot the cam ring 21 about the fulcrum pin 22. In FIG. 2, when the rotor 24 disposed in an eccentric relationship with the cam ring rotates in the clockwise direction, hydraulic fluid is drawn into a suction port 21b from a reservoir 27 through an oil line 28, while a pressurized hydraulic fluid is delivered into an oil line 29 from a delivery port 21c. The eccentricity between the cam ring and the rotor is varied by the pivotal movement of the cam ring. The pressurized hydraulic fluid at the delivery port 29 or in the oil line 29 is regulated to a predetermined pressure (line pressure) by a control valve 30, and is supplied to hydraulic equipment such as a clutch which is not shown. The line pressure of the oil line 29 is led to a control means such as a regulator valve 31 having first and second shift modes for pilot pressure. The operation of the control means is described hereinafter. The regulator valve 31 is connected to an oil line 33 which communicates with the interior of cam ring 21 at a second position, and to an oil line 34 which communicates with the interior of cam ring 21 at a first position diametrically opposed to said second position. For the purpose of the following discussion and the appended claims, that chamber which has passed by the suction port 21b is the first chamber. Similarly, that chamber which has passed by the delivery port 21c is the second chamber. In the preferred embodiment, these two chambers are diametrically opposed. The chambers alternate in becoming the first chamber and second chamber as rotor 24 rotates. Each chamber assumes the identity of first chamber and second chamber once per revolution. There is never more than one first chamber or second chamber. A chamber has "passed by" a port, e.g., suction port 21b, when the trailing vane defining the chamber rotates past the upper clockwise edge of the port. Thus, "passed by" is meant to imply that the port which is passed by is port which the chamber has more recently passed. As illustrated in FIG. 2, oil line 33 communicates with the chamber occupying the angular positions corresponding to the second chamber, and oil line 34 communicates similarly with a first chamber. When the line pressure as a pilot pressure is higher than a preset pressure, both of the oil lines 33 and 34 are shut off, whereas when the line pressure is below the preset pressure, both of the oil lines 33 and 34 are communicated with each other.
The operation of the control device according to the present invention will be described hereinafter.
As the rotor 24 rotates in the clockwise direction as shown in FIG. 2, the hydraulic fluid inside the reservior 27 is drawn into the suction port 21b through the oil line 28, and the hydraulic fluid is delivered into the oil line 29 from the delivery port 21c. It will be noted that the hydraulic fluid is trapped between vanes at two portions (at a suction side and at a delivery side), namely, in a first chamber 35 as shown in the upper side of FIG. 2 and in a second chamber 32 as shown in the lower side of FIG. 2. As described previously, the second chamber 32 and the first chamber 35 are respectively communicated with the regulator valve 31 by the oil lines 33 and 34. Meanwhile, since the second chamber 32 is supplied with and can maintain the delivery pressure (line pressure) at the delivery port 21c, the pressure in second chamber 32 is kept approximately equal to the line pressure, and on the other hand, since first chamber 35 has been subjected to and keeps a decreased pressure of the suction port 21, the pressure in first chamber 35 is substantially zero. A control device of a vane type variable displacement pump according to the present invention controls the amount of eccentricity of the cam ring 21 utilizing a pressure difference between the both chambers 32 and 35. When the line pressure does not reach the preset pressure of the regulator valve 31 because of a low speed of the rotor 24, the regulator valve 31 in a first shift mode allows communication between the oil line 33 and the oil line 34. In other words, it allows communication between the first chamber 35 and the second chamber the delivery 32. Thus, a higher hydraulic pressure at the delivery second chamber 32 is led to first chamber 35, causing the hydraulic pressure at both side chambers to become approximately equal to the line pressure. For this reason, no force resulting from the hydraulic pressure acts upon the cam ring 21. Accordingly, the cam ring 21 is pushed to a position of a maximum eccentricity by a bias force of the spring 25, and a delivery volume is made large. When the rotating speed of the rotor 24 is increased and thus the delivery is increased, the line pressure may exceed the preset pressure of the regulator valve 31. Then, the regulator valve is shifted to a second shift mode, and the communication between the oil line 33 and the oil line 34, that is, between first chamber 35 and second chamber 32, is shut off. At this time, since the hydraulic fluid in second chamber 32 is not supplied to first chamber 35, the hydraulic pressure at first chamber 35 will become substantially zero. Since a hydraulic pressure approximately equal to the line pressure is acting on the second chamber 32, a force turning the cam ring 21 in a counterclockwise direction in FIG. 2 will be imposed thereon. Therefore, the amount of the eccentricity of the cam ring is reduced and a delivery volume is reduced. The higher the line pressure, the larger will be the force acting on the cam ring 21 from second chamber 32, and the larger in this force in turn, the smaller will be the amount of the eccentricity, and thus there will be reduced delivery. Accordingly, the cam ring 21 is balanced at a predetermined position and supplies a minimum required amount of hydraulic fluid required for the whole hydraulic circuit including leakages at the control valve 30, each oil line, clutches etc.
Further, in the above embodiment, although the preset pressure of the regulator valve 31 is made constant by the bias force of a spring, for instance, in such a case that it is desired to increase the delivery temporarily corresponding to the operating conditions of the equipment using this pump, the preset pressure can be varied by imposing a predetermined hydraulic pressure on the regulator valve 31.
As described above, according to the present invention, an oil line communicating with a second chamber of a pump and an oil line communicating with a first chamber of the same are led to a regulator valve, which has a first shift position wherein the oil lines are communicated with each other and a second shift position wherein the communication of the oil lines is shut off. The delivery pressure of the pump is led to the regulator valve as a pilot pressure. When the pump delivery pressure is below a preset pressure, the regulator valve is made to be in the first shift position, whereas when the pump delivery pressure is higher than the preset pressure, the regulator valve is made to be in the second shift position. In addition, a spring is provided to always impose a bias force so as to pivotally turn the cam ring in a direction which produces a larger eccentricity. As a result, a hydraulic cylinder for pivotally turning the cam ring is unnecessary in the present invention. Thus such effects as a lower cost of the pump and a compact control device for the pump have been obtained.
While preferred embodiments of this invention have been shown and described, it will be appreciated that other embodiments will become apparent to those skilled in the art upon reading this disclosure, and, therefore, the invention is not to be limited by the disclosed embodiments, except as required by the hereto appended claims. | There is provided a control device for a vane type variable displacement pump. The control device eliminates the need of a hydraulic cylinder to control the eccentricity of a cam ring of the vane pump. A pressure difference between a second chamber and a high pressure side of the pump first chamber on a low-pressure side of the vane pump is utilized to determine the eccentricity of the cam ring. A regulator valve is connected to the first chamber and with the second chamber in order to allow or prevent communication between the two chambers. A spring is also provided to always force the cam ring in a direction so as to make the eccentricity of the cam ring larger. | 5 |
BACKGROUND
[0001] Modern drainage and sewage systems are closed pipe systems connecting drains in residential or commercial structures to municipally maintained sewer mains. Maintenance of these systems is typically the responsibility of the property owner or community association rather than a municipality. While small structural pipe clogs typically occur due to debris entering an interior drain, larger exterior underground sewage pipes between the structure and a sewer main usually become clogged by roots entering through cracks that develop in pipes over time. As the roots grow in the pipe, they trap additional material, thereby occluding the pipe. Unclogging large underground pipes is a time consuming and expensive process.
[0002] Root cleaners are known in the art. These apparatus, typically consist of drum augers having a spooled heavy gauge cable affixed to a rotating motor. The cable is affixed at one end with a bladed head or similar cutting structure designed to cut through roots and other debris. As the rotating cable is fed into a sewer line, the turning blades cut away roots and other blockage. While conventional drum augers are useful for cutting and clearing large roots and debris, they rotate at relatively slow speeds and are typically equipped with cutting heads smaller in diameter than the pipe being cleaned. The result is that small root fibers at fissures in the pipe are left behind, and ultimately re-grow to cause future blockage.
[0003] Repairing cracked pipes by various lining techniques are also known in the art. Alternatively referred to as “trenchless” repair, these processes involve installing an in situ cured resin or resin-like material along the inner wall of a sewage pipe. The resin is sprayed or otherwise administered to the interior surface of the sewer line. While trenchless repair and installation and produce an interior liner that effectively covers cracks and fissures, occasionally small root fibers extend through the coating and survive, allowing roots to re-grow, spreading cracks through the lining, and shortening its operational life.
[0004] There is therefore a need for a sewer line root cleaning and repair system that prepares a sewer line for effective trenchless re-lining by completely scouring the inside of the sewer line of all debris including fine root hairs. There is also a need for a root cleaning and repair system capable of maneuvering around turns and across pipe junctions without becoming stuck on pipe fittings and other obstacles. There is also a need for a root cleaning and repair system which is impervious to water contamination, and avoids problems inherent in using electrically powered components in a wet environment. There is also a need for a root cleaning and repair system that is lightweight and easy to use, that stores conveniently and portably when not in use, and that may be easily connected to and disconnected from conventional pressurized air lines.
[0005] These and other objects and advantages of the invention are more fully discussed in the following description, drawings and claims.
SUMMARY
[0006] A sewer line root cleaning and repair system includes a root cleaner for clearing a sewer line. The root cleaner includes a first body with at least one first wheel and a motor housed in the first body. A second body is flexibly coupled to the first body by a flexible connector. The second body includes at least one a second wheel. A flexible rotating member having a first end coupled to the motor, extends through the second body and includes a second end coupled to at least one bristle. The motor governs rotational movement of the flexible rotating member, and the second body forms a bearing for the flexible rotating member. Rotational movement in the flexible rotating member drives the bristle against the sewer line, thereby clearing the sewer line.
[0007] The root cleaner includes a flexible pneumatically pressurized line coupled to the first body to supply air to the motor, which is preferably pneumatic. The first body may include multiple opposing first wheels which are retractable and biased to an extended position to preserve the first body in the center of the sewer line. The flexible connector between the first body and the second body encloses the flexible rotating member, and the rotating member preferably includes an adjustable hub anchoring the bristle to the second end of the flexible rotating member. At the end of the bristle, where contact with the sewer line walls is made, the bristle preferably is frayed for improved scouring. In a preferred embodiment, multiple bristles are used.
[0008] The bristle is preferably anchored to the flexible rotating member near a midpoint of the bristle. The first body and the second body preferably include guides for distancing the first body and the second body away from the sewer line. Fasteners may also be included for holding the first body in position around the motor.
[0009] Once the sewer line is cleaned of fine root hairs, a liner sprayer having a first sprayer body and a second sprayer body connected by a second flexible connector is inserted into the sewer line. The second body terminates in a sprayer nozzle opposite the second flexible connector, and the sprayer nozzle configured to produce a hollow cone spray pattern. A pressurized air supply and resin supply is connected to the liner sprayer and resin is sprayed through the liner sprayer to coat the interior surface of the sewer line. The liner sprayer is then removed and once the resin cures, the sewer line is ready for use with a greatly extended serviceable life.
BRIEF DESCRIPTION OF THE FIGURES
[0010] FIG. 1 illustrates a perspective view of a root cleaner of the sewer cleaning system;
[0011] FIG. 2 illustrates a section view of the root cleaner operating in a sewer line;
[0012] FIG. 3 illustrates a side view of a first body of the root cleaner with extended wheels:
[0013] FIG. 4 illustrates a flexible connection between the first body and a second body;
[0014] FIG. 5 illustrates a spool on which the root cleaner is stored before and after use; and
[0015] FIG. 6 illustrates a trenchless lining apparatus having two chassis separated by a flexible connection.
DESCRIPTION
[0016] Referring to FIGS. 1 and 2 , a root cleaner 10 for a sewer line 12 includes a first body 14 . The first body 14 includes at least one first wheel 16 and a motor 18 . The motor 18 is preferably a pneumatic motor 18 translating air pressure into rotational motion at hundreds or thousands of revolutions per minute. The root cleaner 10 also includes a second body 20 connected to the first body 14 by a flexible connector 22 . The flexible connector 22 may be a heavy gauge helical wire, or similar resiliently bendable material. The second body 20 has at least one second wheel 24 , substantially similar to the first wheel 16 . The second body 20 also serves as a bearing for a rotating member 26 .
[0017] The rotating member 26 , which may be a heavy gauge wire or cable, has a first end 28 coupled to the motor 18 , which imparts rotational motion to the rotating member 26 , and a second end 30 coupled to a bristle 32 . Air pressure from a pressurized line 34 inside a sleeve 44 causes the motor 18 to turn the rotating member 26 , which drives the bristle 32 around the inside of the sewer line 12 . To prevent damage to the pressurized line 34 , including undue bending, the pressurized line 34 may be housed in a sleeve 44 .
[0018] In order to center the bristle 32 on the rotating member 26 , to install multiple bristles 32 , or to replace bristles 32 at the end of their operational life, an adjustable hub 36 may be included at the second end 30 of the rotating member 26 . The adjustable hub 36 may also be useful for preserving a bristle 32 in place where the bristle 32 extends through the adjustable hub 36 , and anchors to the adjustable hub 36 at a midpoint of the bristle 32 .
[0019] Still referring to FIGS. 1 and 2 , the first body 14 and the second body 20 also include guides 40 to help avoid obstructions (not shown) in the sewer line 12 from catching on the first wheels 16 or second wheels 24 . The first wheels 16 and the second wheels 24 may be tapered to further prevent catching, and to compliment the curved interior of the sewer line 12 . Preferably the first wheels 16 , and optionally the second wheels 24 are extendable and retractable on swinging axle assemblies 46 , allowing them respectively to ride closer to, or farther away from the first body 14 , and optionally, the second body 20 .
[0020] Unlike the second body 20 , which has a relatively open configuration, the first body 14 preferably completely encases the motor 18 , but includes a fastener 42 allowing the first body 14 to be opened and the motor 18 replaced if needed. The pressurized line 34 for supplying pressurized air to the motor 18 is preferably detachable from the first body 14 via a quick-connect mechanism, typical of pneumatic tools.
[0021] Referring to FIG. 3 , the first body 14 is shown with the first wheels 16 extended. Since the first body 14 is the longest non-bendable portion of the root cleaning and repair system, maintaining the first body 14 centrally in the sewer line 12 (not shown) is necessary to maneuver through bends in its pipes and junctions. As discussed, the first wheels 16 are mounted on swinging axle assemblies 46 , which allow the first wheels 16 to move closer to or away from the first body 14 .
[0022] To accomplish centering, springs 48 are coupled to the swinging axle assemblies 46 , biasing them to an extended position as shown. In the illustrated embodiment the springs 48 are connected between axle assemblies 46 . In other embodiments, the springs 48 may be connected between an axle assembly 46 and the first body 14 . When the first wheels 16 are forced closer to the first body 14 due to the confines of the sewer line 12 , the guides 40 help center the first body 14 and prevent the first wheels 16 from catching on pipe junctions (not shown) and other objects in the sewer line 12 .
[0023] Since the motor 18 (not shown) is cylindrical, the first body 14 preferably conforms to the motor 18 , and is shaped as cylindrical canister. To allow disassembly of the first body 14 , while also achieving the lowest profile, a fastener 42 is positioned to engage a spanning plante 50 , arced in the profile of the first body 14 , oriented lengthwise and parallel to the root cleaner's 10 direction of travel.
[0024] Referring to FIG. 4 , the root cleaner 10 is shown with the second body 20 articulating relative to the first body 14 at the flexible connector 22 . This ability to bend allows the root cleaner 10 to navigate around multiple turns, including upwards of forty five degree turns at pipe connections in the sewer line 12 (not shown). Because the rotating member 26 is also flexible, it will accommodate flexing of the flexible connector 22 . Preferably the material comprising the rotating member 26 allows it to bend smoothly while in rotational motion, thereby allowing continuous operation in the sewer line 12 .
[0025] Although the first body 14 preferably includes articulating axle assemblies 46 and springs 48 , the second body 20 may incorporate conventional axles 50 . When the rotating member 26 is in motion, the bristles 32 tend to center the second body 20 in the sewer line 12 due to centrifugal forces and even pressure around the bristles 32 , avoiding the need for the second wheels 24 to engage the sewer line 12 on articulating axle assemblies 46 . Having conventional axles 50 also reduces the number of moving parts and risk of parts of the root cleaner 10 breaking.
[0026] Referring to FIG. 5 , the sleeve 44 containing the pressurized line 34 (not shown), the first body 14 and the second body 20 are installed on a spool 52 , which is held on a wheeled cart 54 , allowing the root cleaner 10 to be easily moved from place to place. Preferably the spool 52 includes an easily accessible pneumatic valve 56 , allowing a user to easily couple and de-couple an air compressor (not shown) to the pressurized line 34 . The wheeled cart 54 preferably also may include a tool box 58 for containing parts and equipment (not shown), for example different types and sizes of bristles, an extra motor, etc., making the root cleaner 10 fully self contained.
[0027] Referring to FIG. 6 , in addition to the root cleaner 10 (not shown), the sewer cleaning and repair system includes a trenchless sewer liner sprayer 60 . Similar to the root cleaner 10 , the sewer liner sprayer 60 includes a first sprayer body 62 and a second sprayer body 64 connected by a second flexible connector 66 to allow the sewer liner sprayer 60 to travel through pipe bends (not shown). First sprayer wheels 68 are mounted on the first sprayer body 62 and second sprayer wheels 70 are mounted on the second sprayer body 64 , allowing the sewer liner sprayer 60 to roll over debris. Sprayer guides 72 are included to prevent the first sprayer wheels 68 and the second sprayer wheels 70 from lodging on obstructions (not shown).
[0028] A sprayer nozzle 74 extends from the second sprayer body 64 for spraying liner resin (not shown) across the inner surface of a sewer pipe (not shown). To prevent the liner resin from contaminating the sewer liner sprayer 60 , in particular moving parts, such as the first sprayer wheels 68 and second sprayer wheels 70 , a cone 76 extends forward around the sprayer nozzle 74 . A coating such as liner resin for example is fed through the sewer liner sprayer 60 by a coating line 78 , which also travels through the first sprayer body 62 , second flexible connector 66 and second sprayer body 64 before terminating at the sprayer nozzle 74 where it is ejected as a hollow cone.
[0029] The coating line 78 is preferably stored on a sprayer spool 80 , mounted on a wheeled sprayer cart 82 . Like the wheeled cart 54 of the root cleaner 10 , the wheeled sprayer cart 82 also preferably includes a sprayer tool box 84 having parts and equipment (not shown) useful for maintaining and repairing the sewer liner sprayer 60 . A liner resin tank 86 is also mounted on the sprayer cart 82 , with a fluid valve 88 used to ensure the right pressure of liner resin (not shown) entering the liner resin tank 86 and subsequently the coating line 78 .
[0030] Because liner resin is mixed with pressurized air prior to expulsion through the sprayer nozzle 74 , the sprayer cart 82 also has a pneumatic valve 56 for attaching a pressurized air line (not shown). Preferably the same type of pneumatic valve 56 will be used for the liner sprayer 60 and the root cleaner 10 , enabling the same pressurized air line to be used for both apparatus.
[0031] The structure of the sewer line root cleaning and repair system having been shown and described, its method of use will now be discussed.
[0032] Referring to FIGS. 1-6 , in order to use the system, a user wheels the root cleaner 10 on its cart 54 to a sewer line 12 clean-out (not shown) or similar access point. A pressurized air source, such as an air compressor hose (not shown) is attached to the pneumatic valve 56 . The pneumatic valve 56 may be coupled to a control (not shown) for controlling air pressure in the pressurized line 34 , and thus, the speed of the bristles 32 . Prior to activation, with the pneumatic valve closed, the bristles 32 may be adjusted on the adjustable hub 36 as desired, or may be removed and replaced with new or appropriately sized alternative bristles 32 .
[0033] The root cleaner 10 is then unspooled and fed down the sewer line 12 , with air pressure raised in the pressurized line 34 as desired to activate the root cleaner 10 and control rotational speed. Pressurized air (not shown) travels through the pressurized line 34 and enters the first body 14 , encountering the motor 18 therein. The motor 18 translates air pressure into rotational movement, causing the rotating member 26 to rotate up to thousands of RPM depending on the air pressure in the pressurized line 34 .
[0034] As the motor 18 rotates, the rotating member 26 rotates in tandem, extending through the flexible connection 22 and through the second body 20 , which essentially acts as a bushing to ensure smooth operation. The rotating member 26 , terminating in front of the second body 20 , rotates the bristles 32 at a high rate of speed. With the bristles 32 rotating at a speed sufficient to scour interior surfaces, the root cleaner 10 is fed along the sewer line 12 . As the root cleaner 10 encounters corners and turns, the flexible connector 22 allows the second body 20 to bend relative to the first body 14 and maneuver through numerous convolutions in the sewer line 12 . As the sewer line 12 increases and decreases in diameter, the axle assemblies 46 cause the first wheels 16 to extend outward from the first body 14 and retract toward it as necessary.
[0035] As the bristles encounter roots, root fibers, or other intrusive objects, they scrape them away, scouring the sewer line 12 to a smooth polished surface. Once the intended portion of the sewer line 12 is cleaned of roots, the pneumatic valve 56 is closed, air pressure bled from the pressurized line 34 , and the root cleaner 10 is removed from the sewer line 12 as a user rolls it back up on the spool 52 . The cart 54 may then be moved and stored for future use.
[0036] With the sewer line cleaned, the user then maneuvers the sprayer cart 82 into position at the access point. Before or after inserting the line sprayer 60 , the user attaches the pressurized air source to the pneumatic valve 56 on the sprayer spool 80 . The user may also connect a coating supply such as liner resin to the coating line 78 , filling the liner resin tank 86 . The liner sprayer 60 is fed down the sewer line to the area intended to be lined with resin. As the liner sprayer 60 moves through the sewer line, the first sprayer wheels 68 and second sprayer wheels 70 help guide it along the way, with the sprayer guides 72 preventing them from being obstructed.
[0037] To activate the liner sprayer 60 , air and liner resin are forced through the coating line 78 , passing through the first sprayer body 62 , the second flexible connector 66 and the second sprayer body 64 . The pressurized mixture passes through the sprayer nozzle 74 , forming a hollow cone that coats the entire inner surface of the sewer pipe with liner resin to a desired thickness. The sprayer cone prevents atomized resin sprayed from the sprayer nozzle 74 from contaminating moving parts of the liner sprayer 60 , such as the first sprayer wheels 68 and second sprayer wheels 70 .
[0038] Once the liner resin is sufficiently applied, the user closes the fluid valve 88 to stop the resin supply and closes the pneumatic valve 56 to stop the flow of pressurized air. The user then withdraws the liner sprayer 60 by rolling the coating line 78 up on the sprayer spool 80 . With the sewer line scoured of fine root hairs and a smooth coat of liner resin applied over fractured portions of the sewer pipe, the serviceable life of the sewer line is greatly extended.
[0039] The foregoing description of the preferred embodiment of the Invention is sufficient in detail to enable one skilled in the art to make and use the invention. It is understood, however, that the detail of the preferred embodiment presented is not intended to limit the scope of the invention, in as much as equivalents thereof and other modifications which come within the scope of the invention as defined by the claims will become apparent to those skilled in the art upon reading this specification. | A sewer line root cleaning and repair system includes a root cleaner having a first body and a second body connected by a flexible connector. A flexible rotating member extending from a pneumatic motor in the first body extends through the flexible connector and the second body. The flexible rotating member terminates beyond the second body in a series of bristles. As the root cleaner moves through a sewer line a set of wheels on the first body extends outward, centering the first body in the sewer line as the bristles spin at high RPM centering the second body in the sewer line and scouring the sewer line free of roots including small root hairs. Afterward, a coating sprayer is inserted into the sewer line, connected to a coating supply and air supply, and the coating is sprayed under pressure to line the inner surface of the sewer line. | 5 |
FIELD OF THE INVENTION
[0001] The present invention pertains to a process for the reliable operation of turbocompressors with surge limit control and a surge limit control valve, wherein the compressor delivers gases of different compositions, and the composition of the gas (molecular weight) affects the performance characteristic of the turbocompressor and consequently the position of the surge limit in the performance characteristic.
BACKGROUND OF THE INVENTION
[0002] DE 198 28 368 C2 discloses a process for operating two-stage or more than two-stage compressors, in which each compressor stage has a separate surge limit control valve arranged between a delivery line via a blow-by line and an intake line. The surge limit control valve blows off into the intake line of the corresponding compressor stage. Furthermore, a flow computer for computing the intake flow as well as a computer for the minimum allowable desired flow, which is determined from the end pressure or the delivery head, are provided.
[0003] Furthermore, EP 0 810 358 A2 discloses a process for controlling gas pressures of a regenerator with a gas expansion turbine in the flue gas line with a generator, wherein a process controller opens the inlet fittings of a gas expansion turbine and/or the bypass fittings or throttles the bypass fittings. A plurality of resolver transmitters, which preset the manipulated variables for the downstream fittings, are arranged downstream of the process controllers.
[0004] Moreover, DE 100 12 380 A1 discloses a process for protecting a turbocompressor with the downstream process from operation in the unstable working range, wherein a machine controller is used, which optionally has a suction pressure controller, an end pressure controller and a bypass controller, besides a surge limiter. A control matrix is determined from the position of a control unit that determines the flow to the process, optionally taking into account additional influencing variables, such as the compressor suction pressure and the compressor outlet pressure and the compressor suction temperature as well as the process pressure. Based on the control matrix, the necessary position of the surge limit control valve as well as of the bypass valve, of the suction pressure control valve and of the actuating drive is determined directly for the compressor inlet blades in the case of a rapid transient change in the working point. The actuating variable determined is then sent directly as a manipulated variable to the surge limit control valve, the suction pressure controller, the end pressure controller and the bypass controller.
[0005] Furthermore, EP 0 757 180 B1 discloses a process for avoiding controller instabilities in surge limit controls for protecting a turbocompressor from surging if the proportional sensitivity of the surge limiter was selected to be too high by means of blow-off via a blow-off valve. The speed with which the blow-off valve closes over time takes place is controlled by means of an asymmetric gradient limiter, with no time limitation being effective in the opening direction. However, a parametrizable time limitation of the closing operation of the blow-off valve is provided in the closing direction.
[0006] It is assumed in the prior-art processes that the position of the surge limit in the performance characteristic of the compressor is known. The coordinates of the working point are usually plotted in the performance characteristic as compression work or enthalpy difference or delivery head as a function of the suction volume flow. The parameters of the particular variables must be known as well.
SUMMARY OF THE INVENTION
[0007] The basic object of the present invention is to propose a process for the reliable operation of a turbocompressor, which is also able to reliably process gases of different compositions, which is not sufficiently known especially concerning the variables for the gas constant R and the isentropic exponent k. The basic object is accomplished in that the different compositions of the gases are compensated with the effect on the position of the surge limit and consequently also on the location of the surge limit control line by using predetermined design values for the gas constant R, the isentropic exponent k and the compressibility number z within the surge limit control for the determination of the delivery head (enthalpy difference) Δh and the volume flow V and plotting them in the form of a predetermined surge limit control line (FIG. 2, FIG. 4) within the surge limit control, the set point and the actual value for the surge limit control being determined from the graph and the compressor being operated with the set points and actual values determined for the surge limit control with a minimally necessary distance from the surge limit.
[0008] Furthermore, it proved to be advantageous to plot a number of characteristics with constant speed or with constant geometry (guide vane position or position of a throttling fitting), wherein a family of curves each is described with surge limit lines for a constant speed or constant compressor geometry and to interpolate between the different curves and to correctly determine the surge limit control line for each speed or compressor geometry, and to operate the surge limiter with the minimally necessary distance from the surge limit.
[0009] Moreover, it proved to be especially advantageous that a single “fictitious” control line, whose position depends on the performance characteristic and is determined by the surge points located farthest to the right, is plotted instead of the interpolation between different surge limit control lines.
[0010] As an alternative, the process can be used for reliably operating turbocompressors with surge limit control and a surge limit control valve in which the compressor delivers gases with different compositions and the composition of the individual gases (molecular weight) leaves the performance characteristic of the turbocompressor and consequently the position of the surge limit in the performance characteristic unaffected, and a predetermined design value for the gas constant R, the isentropic exponent k and the compressibility number z is used within the surge limit control for determining the delivery head Δh and the volume flow V, and it is plotted in the form of a predetermined surge limit line (FIG. 1) within the surge limit control, wherein the set point for the surge limit control is determined from the graph and the actual value is calculated from the measured variables determined, and the compressor is operated with the set points and actual values determined for the surge limit control with a minimally necessary distance from the surge limit.
[0011] The position of the surge limit in the performance characteristic of a compressor is made use of in the surge limit control as one of the essential protective means for turbocompressors. The minimum allowable flow through the compressor is determined as the set point for the surge limiter from the enthalpy difference within the surge limit control. Correct surge limit control and consequently reliable protection of the machine are then possible in the knowledge of the enthalpy difference and the volume flow.
[0012] The formulas for determining the coordinates of the enthalpy difference delta h or Δh and the volume flow V are as follows:
Δ h = k · R · z · T 1 k - 1 · [ { p 2 p 1 } k - 1 k - 1 ] and V . = K Δ p 1 · R · z · T 1 p 1
[0013] in which
[0014] R is the gas constant,
[0015] k is the isentropic exponent,
[0016] z is the compressibility number,
[0017] T 1 is the temperature on the intake side,
[0018] p 1 is the pressure on the intake side,
[0019] p 2 is the pressure on the delivery side,
[0020] K is the parametrization constant for the flow, and
[0021] Δp 1 is the differential pressure over the differential pressure sensor on the intake side.
[0022] The parameters R and k as well as z depend on the gas composition. R is the gas constant, k is the isentropic exponent, and z is the compressibility number. The composition of the gas being compressed by the compressor is usually known. Only one gas, e.g., air, nitrogen or a process gas with a composition that is constant over time is compressed in a chemical process in the overwhelming majority of cases. The variables R, k and z are constant over the entire operating time of the compressor and can therefore be taken into account as constants in the formulas for calculating the enthalpy difference and the volume flow. The variables enthalpy difference and volume flow are determined physically correctly in this case.
[0023] However, processes in which the composition of the gas may change over time are also known in some applications, especially in the chemical industry. The variables R, k and z are no longer constant in this case, but they must be considered to be variables that change over time. If the variables R, k and z can always be presumed to be constant or to be able to be accurately determined by measurement at any time, these can be taken into account within the underlying formulas. The enthalpy difference and the volume flow are also determined physically correctly in these cases. Reliable protection of the machine by means of the correctly determined values for the set point and the actual value is possible.
[0024] By contrast, compressors are operated in other applications with variable gas composition, where the gas composition is not known in the particular case. The shape of the surge limit, which shape must be taken into account within the surge limit control, is different with different compressors depending on the composition of the gas. However, it is normally impossible to take into account a different shape of the surge limit without the knowledge of the gas parameters R, k and z.
[0025] The process according to the present invention is therefore to be used in the case of compressors for which the shape of the surge limit or the surge limit control line in the performance characteristic shows a dependence on at least one gas composition.
[0026] A process will be described below by means of which it is possible to exactly determine the difference between the set point and the actual value for the surge limit control even if the gas composition is not known and thus to optimally protect the compressor from operating in the unstable range.
[0027] The process will be described below on the basis of exemplary embodiments, whose characteristics are shown. For better understanding, the process will first be described for a compressor with constant speed and constant geometry (fixed guide vanes and without throttling fitting). The process will subsequently be generalized to any compressor.
[0028] The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] [0029]FIG. 1 is a diagram showing the characteristic of a compressor with constant speed and fixed geometry;
[0030] [0030]FIG. 2 is a diagram showing the characteristics of a compressor for two gases;
[0031] [0031]FIG. 3 is a diagram showing the characteristics of a compressor for five different gases;
[0032] [0032]FIG. 4 is a diagram showing the characteristics of a compressor for similarly different gases as in FIG. 3;
[0033] [0033]FIG. 5 is a diagram showing the characteristics of a compressor for different angles of the adjustable guide vanes;
[0034] [0034]FIG. 6 is a diagram showing the characteristics of a compressor at a percentage of the nominal speed for two gases; and
[0035] [0035]FIG. 7 is a diagram showing the control characteristics of a compressor with surge limits of two gases and a selected control line.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Referring to the drawings in particular, FIG. 1 shows the characteristic of a compressor with constant speed and fixed geometry.
[0037] There are compressors for which the performance characteristic according to FIG. 1 is independent from the gas composition. The characteristic in the performance characteristic Δh over V is such that this is generally valid for all gases being delivered.
[0038] Other compressors are designed such that a different characteristic with another surge point is obtained for each gas composition.
[0039] [0039]FIG. 2 shows, for example, the characteristic of a compressor whose characteristic and consequently also the position of the surge point depend on the gas composition.
[0040] The essential difference between the case according to FIG. 1 and that according to FIG. 2 is that in the case of a universally valid characteristic according to FIG. 1, the characteristic and consequently the surge point needs to be calculated for one gas composition only. The shape of the characteristic needs to be valid for one gas only during the acceptance measurements in the test shop.
[0041] If another characteristic applies to each gas composition, as is shown in FIG. 2, the compressor shall be designed thermodynamically for all occurring gas compositions or at least for some representative gas compositions. The characteristics are then to be verified in the test shop by corresponding measurements with different gases.
[0042] The difference shown is not of any special significance for the process described below. The difference is mentioned only for completeness' sake.
[0043] A compressor according to FIG. 1 will first be assumed below.
[0044] To determine the position of the working point in the performance characteristic, it is necessary to exactly determine the delivery head Δh and the volume flow V. As a result, the position of the current working point relative to the surge limit can be determined. Because of the known formulas for the delivery head Δh and the volume flow V, this requires the exact knowledge of the variables R, k and z. However, these variables are often unknown. It is therefore assumed that the variables R, k and z cannot be determined by measurement and cannot be used as known variables for the determination of Δh and V. Consequently, only a single parameter set for R, k and z can be used in the determination of the working point. Different parameter sets cannot be used, because there is no criterion according to which a change-over between the different parameter sets can be performed.
[0045] The data of the gas composition, with which the compressor is operated for most of the time, are usually used for the change-over to different parameter sets, and the values of the gas composition for which the compressor was designed (hereinafter also called design values) are used. The position of the working point in the performance characteristic is also determined correctly as long as the composition of the gas being delivered exactly corresponds to the design.
[0046] If, by contrast, the composition of the gas has changed, a computer provided for determining the delivery head Δh and the volume V cannot determine these values correctly any longer because the variables R, k and z cannot be determined by measurement. Instead of the correct values for R, k and z, the computer uses only incorrectly preset values. An error will occur, whose value depends on the deviation of the current gas composition from the design values used for Δh and V in the formula for the calculation.
[0047] The characteristic from FIG. 1 can be converted into “fictitious” characteristics in the knowledge of the assumed errors because the values of R, k and z cannot be determined by measurement. The characteristics which are determined by the surge limiter with the use of the incorrectly preset values for R, k and z are then obtained.
[0048] [0048]FIG. 3 shows the shape of the particular compressor characteristics for different gas compositions according to FIG. 1, the way the shape is determined by a surge limiter without the knowledge of the actual gas composition. A different characteristic with a different surge point is obtained for each gas mixture. Different surge points, which can be connected by a line, are formed from the surge point in FIG. 1. The surge point in FIG. 1 thus becomes a “fictitious” surge limit line.
[0049] The fictitious surge limit line can be reproduced within the surge limit control, and a control line according to the “fictitious” surge limit line can be preset for the protection system of the compressor (surge limit control). Normal features of the surge limit control are used for this. Each surge limit control is designed, e.g., to control a compressor with variable speed or variable geometry. Each of such compressors is described by a performance characteristic with different speed characteristics or different geometries (guide vane position or throttle valve position). Each of the characteristics of such a “normal” compressor ends in a surge point. The connection of such surge points yields the surge limit line. Analogously to this, a surge limit line of equal form is obtained for a compressor with fixed geometry and fixed speed in the case of variable gas composition. The surge limiter consequently requires no additional features to also cover the case of any variable gas composition with fixed geometry and fixed speed.
[0050] The process operates according to the method that the controller error, which arises from the fact that the actual gas composition is unknown to the surge limiter of a compressor, is predetermined during the determination of the “fictitious” surge limit. The inevitably arising error is thus sent to the surge limiter in advance in a superimposing manner by the computer provided, in which the occurring error was taken into account in advance. Due to the fact that the occurring errors were taken into account in advance, the compressor can be protected reliably and accurately during the operation of a compressor with different gases even if the gas composition of the gas being actually delivered is not known at all.
[0051] The process can also be applied in a compressor whose characteristic shows a dependence on the gas composition according to FIG. 2. For example, the data for the gas composition, with which the compressor is frequently operated, shall be used in the surge limiter to determine the variables Δh and V. The corresponding data shall be those according to the upper characteristic in FIG. 2.
[0052] Similarly to FIG. 3, five characteristics are plotted in FIG. 4. The upper characteristic corresponds exactly to the upper characteristic according to FIG. 3. The other characteristics are shifted in relation to those in FIG. 3. The characteristics were converted such that the same values that apply to the other characteristics were used instead of the correct values for R, k and z. The view in FIG. 4 thus corresponds to the view in FIG. 3. A “fictitious” surge limit, which has universal validity even if the composition of the gas currently being delivered is unknown, is obtained in both cases.
[0053] A universal control line, which optimally protects the compressor in the entire range of use even without the knowledge of the gas composition, can be derived from the “fictitious” surge limit line according to FIGS. 3 and 4.
[0054] It is irrelevant which parameter set is used for which gas composition, the only thing that is important being that the same parameter set be always used.
[0055] The purpose of the surge limit control is to always operate the compressor as close to the surge limit as possible. A control deviation between the minimally allowable flow and the current flow is formed for this purpose and sent to the surge limiter. Due to the formation of a control deviation, the fictitious surge limit line assumes such a shape that the calculation errors occurring because of the unknown variables R, k and z of a gas composition will mutually offset each other during the determination of Δh and the current volume flow V.
[0056] If the surge limit line thus determined is used within the surge limit control, the compressor is always sufficiently protected from operating in the unstable range of the performance characteristic, even if the gas composition is subject to greater variations.
[0057] The process becomes somewhat more complicated when the compressor is operated with variable speed or with variable geometry (guide vanes, inlet guide vane or throttling fitting) and variable gas composition. A surge limit line or a surge limit control line is already obtained in the case of compressors of such a design only in the case of constant gas composition. As is known, the compressor must never be operated beyond, i.e., to the left of the surge limit line. To make it possible to ensure this, a control line is positioned to the right of the surge limit with a sufficient safety margin such that the surge limiter can always operate the compressor outside the surge limit range even under extreme operating conditions.
[0058] There are many turbocompressors, especially multi-stage machines, in which especially the course of the surge limit line in the performance characteristic depends on the gas composition.
[0059] A surge limit line or a surge limit control line of a different shape may be obtained for each gas composition in the case of variable geometry or variable speed and variable gas composition. The surge limit line or the surge limit control line becomes a family of surge limit lines and surge limit control lines.
[0060] Each characteristic of the original performance characteristic (FIG. 5) is determined in advance for the different gas compositions according to the above-described process. A surge limit line, which is valid for this speed or for this throttle valve position or guide vane position only, is obtained from the surge point of the characteristic. The application of this process to all characteristics of the original performance characteristic leads to a family of surge limit lines. Each of these lines is valid for one speed or guide vane position or throttle valve position. Since the speed and the position of the throttle valve or guide vane can be determined by measurement in a simple manner, the surge limit line valid for the particular speed and throttle valve position or guide vane position can always be preset for the surge limiter. Interpolation between the characteristics can be performed by means of the central computer unit, so that the presetting must be performed for a limited number of characteristics only.
[0061] The measurement of the speed and the guide vane position or the throttle valve position is done away with in another, simpler approach. As a result, the apparatus required becomes simpler and the entire system hence becomes less expensive, but the usable range of the performance characteristic becomes somewhat limited, because the most unfavorable case is always assumed in this process.
[0062] One advantage of the simplified approach is that the classical surge limit control can be used for the protection of such compressors without any modification. The necessary surge points for the different compressor geometries or speeds and the possible gas compositions shall preferably be taken into account for this in a common performance characteristic. A surge limit range is obtained as a result. The shape of the surge limit line that is decisive for the surge limit control is obtained by connecting the surge points located farthest to the right, i.e., at the greatest volume flows. It is ensured as a result that regardless of the particular gas composition used, which is, however, unknown, there is a sufficient safety margin from the current surge limit.
[0063] [0063]FIG. 6 shows the two performance characteristics of a surge limit control at a percentage of the nominal speed for two gases.
[0064] [0064]FIG. 7 shows the position of the predetermined “fictitious” surge limit lines for the two gases as well as the corresponding control line selected, whose position depends on the surge limit located farthest to the right.
[0065] By changing the gas composition, the fictitious surge limit line or the universal surge limit control line widens into a performance characteristic of fictitious surge limit lines or universal control lines.
[0066] The performance characteristics of fictitious surge limit lines or universal control lines are shown in FIGS. 5 and 6. The characteristic in FIG. 1 becomes the performance characteristic according to FIG. 5 because of the variable speed or the variable geometry. Each of these characteristics (for a fixed gas composition) according to FIG. 5 can be converted into a performance characteristic (for variable gas composition) according to the above-described process. Since each of the characteristics is limited by a surge point, a surge limit line is obtained in each of the performance characteristics. Since each characteristic in FIG. 5 is characterized by a fixed speed and a fixed compressor geometry, each performance characteristic in FIG. 6 and consequently each surge limit line in FIG. 6 is characterized by a fixed speed and a fixed compressor geometry.
[0067] Since both the speed and the compressor geometry (which is variable due to adjustable guide vanes or throttling fittings) can be easily determined by measurement, the characteristic that is relevant for the particular mode of operation can always be selected by measuring the speed and the compressor geometry.
[0068] Operating points between two characteristics can be accurately determined by numeric interpolation.
[0069] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A process for the reliable operation of turbocompressors with a surge limit control and a surge limit control valve is described, in which the compressor delivers gases with different compositions and the composition of the gas (molecular weight) affects the performance characteristic of the turbocompressor and hence the position of the surge limit in the performance characteristic. The different compositions of the gases are compensated here with the effect on the position of the surge limit and consequently on the position of the surge limit control line by using predetermined design values for the gas constant R, the isentropic exponent k and the compressibility number z within the surge limit control for the determination of the delivery head Δh and the volume flow V and plotting them in the form of a predetermined surge limit line (FIG. 2 , FIG. 4 ), wherein the set point and the actual value are determined for the surge limit control from the graph, and the compressor is operated with the set points and actual values determined for the surge limit control with a minimally necessary distance from the surge limit. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to portable communication equipment that utilize retractable antennas. More particularly, the present invention relatesp 2 More particularly antenna for portable communication equipment that provides performance for the selected mode, retracted or extended, independent of the other mode.
2. Problems in the Art
Generally speaking, there are six related designs commonly used in the field of retractable antennas. Perhaps the simplest design is the fixed length linear whip radiator that has an electrical contact on one end, which makes contact with an electrical connector when the radiator is pulled out of the electronic device. In such a design, retraction of the radiator is accomplished by pushing the whip radiator downwardly from its connection with the connector and into the electronic device.
A further design in the prior art is the telescopic whip that is used for portable consumer products. The telescopic whip generally consists of progressively smaller diameter tubes that fit within the next tube. Such a technique permits the antenna to be collapsed or retracted to a length only slightly longer than the largest diameter tube.
U.S. Pat. No. 4,868,576 discloses a third type of design that consists of a linear whip radiator that is air-coupled to a monofilar helical matching device in the extended position. In the retracted mode, the monofilar matching helical device is used as the electromagnetic radiator.
U.S. Pat. No. 5,204,687 discloses yet another type of retractable antenna. U.S. Pat. No. 5,204,687 describes the retractable antenna as being a 1/4 wavelength retractable antenna that consists of a thin linear radiator having an isolated, short monofilar helical radiator on the end thereof. In the extended mode of operation, the thin linear radiator functions as a whip radiator having approximately a 1/4 wavelength electrical length. The helical radiator section is positioned on the upper end of the linear radiator and is isolated therefrom by a short section of dielectric preventing the helical radiator from being in the electrical circuit when the antenna is extended. When the antenna is in the retracted mode, the helical radiator is in the electrical circuit due to the retraction of the linear radiator into the electronic device with the helical radiator's electrical connection being made by a short metal tube below the helical radiator.
Yet another type of retractable antenna is that manufactured by Centurion International that consists of a 1/2 wavelength thin linear radiator with a short monofilar helical radiator connected to the end thereof. In either mode of operation, retracted and extended, the entire antenna package is in the electrical circuit.
SUMMARY OF THE INVENTION
A retractable antenna for a portable communication device such a cellular telephone, two-way radio, etc., is provided which offers maximum performance in the selected mode of operation, retracted or extended, independent of the other mode. Further, a seamless connection between modes is provided by a switching mechanism so that an electromagnetic radiator is always in-circuit during the transition between modes. More particularly, the retractable antenna is adapted to be mounted on a portable communication device including a housing having a receptacle at the upper end thereof which is RF coupled to the circuitry of the device. The antenna includes a first metal connector element for RF connection to the receptacle and has an elongated bore extending between the upper and lower ends thereof. The lower end of an elongated, hollow housing is secured to the first metal connector and extends upwardly therefrom. The housing is comprised of a dielectric material and has an opening formed in the upper end thereof. A helical radiating element is positioned in the dielectric housing as is a normally open electrical switch. The electrical switch, when in its closed position, electrically connects the first metal connector element and the helical radiating element. An elongated radiator is also provided and has a second metal connector element secured to the lower end thereof. A dielectric body member encloses the elongated radiator above the second metal connector and has an upper end portion which extends upwardly beyond the upper end of the elongated radiator. The dielectric body member slidably extends through the opening in the upper end of the housing. The elongated bore in the first metal connector element slidably receives the second metal connector element and the dielectric body. The elongated radiator is movable, with respect to the housing and the receptacle therein, from a retracted position to an extended position. The second metal connector element is in electrical contact with the receptacle when the elongated radiator is in its extended position. The switch is in its normally open position when the elongated radiator is in its extended position so that the helical radiator is inoperative when the elongated radiator is in its extended position. The upper end portion of the dielectric body member is positioned within the helical radiator when the elongated radiator is in its retracted position to isolate the elongated radiator from the helical radiator. A switch actuator is associated with the elongated radiator for positioning the switch in its closed position when the elongated radiator is moved downwardly from its extended position towards its retracted position.
In an alternative embodiment, a metal sliding contact which is in the form of a collar is mounted on the dielectric body member below the upper end thereof. When the antenna is in its retracted position, the metal collar is in electrical contact with a lower contact, which is in contact with the housing receptacle and the helical radiating element. When the antenna is in its extended position, the lower contact is in electrical contact with the metal connector positioned on the lower end of the elongated radiator.
A principal object of the invention is to provide a retractable antenna which provides performance for the selected mode, retracted or extended, independent of the other mode.
A further object of the invention is to provide a retractable antenna designed so that maximum performance of the antenna is provided in the selected mode of operation.
Another object of the invention is to provide a retractable antenna having a seamless connection provided by a switching mechanism so that an electromagnetic radiator is always in-circuit during the transition between modes.
Yet another object of the invention is to provide a retractable antenna which provides electrical performance equivalent to the performance obtained with independent antennas in a single mechanical package.
Yet another object of the invention is to provide a retractable antenna wherein electromagnetic radiators therein are electrically isolated from one another when the antenna is in its retracted position and when the antenna is in its extended position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating a cellular telephone and an antenna;
FIG. 2 is an exploded perspective view of the antenna of the present invention;
FIG. 3 is a sectional view of the retractable antenna in the extended position;
FIG. 4 is a sectional view of the retractable antenna in the retracted position;
FIG. 5 is a perspective view illustrating a cellular telephone having a modified form of the antenna provided thereon;
FIG. 6 is a perspective view of the modified antenna of FIG. 5;
FIG. 7 is a longitudinal sectional view of the antenna of FIGS. 5-6 in an extended position;
FIG. 8 is a longitudinal sectional view of the antenna of FIGS. 5-7 in a retracted position; and
FIG. 9 is an enlarged partial sectional view of the antenna in its retracted position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will be described as it applies to its preferred embodiment. It is not intended that the present invention be limited to the described embodiment. It is intended that the invention cover all alternatives, modifications, and equivalents which may be included within the spirit and scope of the invention. In its preferred embodiment, the present invention applies to a conventional cellular telephone transceiver. Since the present invention applies to both radio receivers and transmitters, for purposes of this application, the term "transceiver" will be deemed to include a receiver, a transmitter, or a combination of the two unless otherwise specified. Further, for the purposes of this application, the terms "portable communication equipment" or "portable communication device" shall be deemed to include a cellular telephone, two-way radio, a receiver, or a transmitter.
In FIG. 1, the numeral 10 refers to a cellular telephone having a housing 12 and an antenna 14. The antenna 14 is electrically connected to the internal circuitry of the telephone 10 through a connector element 16 as will be described in more detail hereinafter.
Antenna 14 includes a first metal connector element 50 for RF connection to the connector element 16 in conventional fashion. For purposes of description, connector element 50 will be described as having a lower end 18 and an upper end 20. The numeral 22 refers to an elongated, hollow housing comprised of a suitable dielectric material. As seen in the drawings, housing 22 is comprised of a lower end portion 24 and an upper end portion 26 which are joined together. However, housing 22 could be comprised of a single piece member if so desired. The lower end of lower end portion 24 of housing 22 embraces and is secured to connector 16 as illustrated in FIGS. 3 and 4. The upper end of upper end portion 26 of housing 22 has an opening 28 formed therein as will be described in more detail hereinafter.
A helical radiating element 30 is mounted in the interior of housing 22 and is preferably provided with a contact element electrically connected to the lower interior thereof as seen in the drawings and which is referred to generally by the reference numeral 32.
A normally open electrical switch 34, preferably comprised of beryllium copper, is mounted in the housing 22 and has its lower end in electrical contact with the connector element 16 as seen in FIG. 3. Switch 34 preferably includes a plurality of flexible finger elements 36 which extend upwardly from the lower end thereof. Preferably, each of the fingers 36 includes a lower end portion 38 and an upper end portion 40 having an annular detent portion 42 positioned therebetween. When switch 34 is in its normally open position, upper end portions 40 of the fingers 36 do not electrically engage the electrical contact 32. However, when switch 34 is moved to its closed position, as will be described in more detail hereinafter, the upper end portions 40 of the fingers 36 electrically engage the contact 32.
The numeral 44 refers generally to an elongated radiator, preferably comprised of nickel-titanium, having an upper end 46 and a lower end 48. The metal connector element 50 is electrically connected to the lower end of the elongated radiator 44 as seen in the drawings. Connector element 50 may be slidably received in the elongated bore 51 formed in connector element 16 and has a stop 52 formed therein which engages the lower end of connector element 16 when the elongated radiator 44 is in the extended position (FIG. 3). When the elongated radiator 44 is in its extended position, as seen in FIG. 3, the connector element 50 is RF coupled to the connector element 16. The upper end of connector element 50 is provided with a recess portion 54 formed therein which is adapted to receive the detent portions 42 of the fingers 36, when the antenna is in its fully extended position, as illustrated in FIG. 3. A dielectric body member 56 embraces radiator 44 above connector element 50 as seen in the drawings and has an upper end portion 58 which extends beyond the upper end 46 of the radiator 44. The upper end of the upper end portion 58 is provided with an enlarged head portion 60 which is provided to limit the inward movement of the antenna with respect to the housing 22 (FIG. 4).
When the antenna is in its retracted position, as illustrated in FIG. 4, the enlarged head portion 60 of the dielectric body member 56 is positioned adjacent the upper end of the housing 22. When the antenna is in its retracted position (FIG. 4), the elongated radiator 44 is positioned below the helical radiator 30. As also seen in FIG. 4, the upper end portion 58 of body member 56 is positioned within the helical radiator 30, when the antenna is in its retracted position, so that there will be no electrical interference between the elongated radiator 44 and the helical radiator 30.
When the antenna is in its retracted position, as illustrated in FIG. 4, the engagement of the detent portions 42 of the fingers 36 with the dielectric body member 56 causes the fingers 36 to be moved outwardly so that the upper ends of the fingers 36 electrically engage the contact 32 so that the helical radiator 30 is RF coupled to the circuitry of the telephone. When the antenna is in its retracted position, the elongated radiator 44 is not RF coupled to the telephone circuitry so that the helical radiator 30 functions independently of the elongated radiator 44. The opening of switch 34 is caused by detent portions 42 being received by the recess portions 54 of connector element 50.
When it is desired to move the antenna from its retracted position to its extended position, the operator grasps the enlarged head section 60 and pulls the antenna upwardly with respect to the telephone. During the upward movement of the antenna to its extended position, the helical radiator 30 remains functional and does remain functional until the detent portions 42 "snap in" the recess portions 54, at which time the switch 34 opens. At the same time, the elongated radiator 44 is RF coupled to the telephone circuitry by means of the electrical connection between connector 50 and connector 18. Electrical connection between the telephone circuitry and elongated radiator 44 is achieved, when the antenna is in its fully extended position, by the electrical contact between the fingers 36 and the connector element 50. Electrical connection between the telephone circuitry and radiator 44 is also achieved, when the antenna is in its fully extended position, by the electrical contact between connector element 50 and connector element 16. Thus, when the antenna is in its fully extended position, the elongated radiator 44 is functional and the helical radiator 30 is non-functional.
A unique feature is also provided in that the engagement of the lower exterior portion of the dielectric body member 56 and the detent portions 42 causes the upper ends of the fingers 36 to electrically contact the contact 32 of helical radiator 30 as soon as the antenna is moved from its fully extended position so that there is no intermittent or partial contact that occurs during extension or retraction so that the circuit has a very positive make/break design. The positive make/break design of the antenna minimizes dropped calls because of the positive switch action. This is achieved, as previously stated, since one of the radiators is always in operation without any gap between the switching during the retraction or extension operation of the antenna.
Thus it can be seen that a unique retractable antenna has been provided which provides maximum performance in the selected mode of operation. It can also be seen that a unique switching mechanism has been provided which provides a seamless connection between the modes so that an electromagnetic radiator is always in-circuit during the transition between modes.
It should be noted that the antenna is ideally suited for use with cellular telephones, although the antenna may be used with other portable communication devices such as two-way radios, receivers, transmitters, etc.
FIGS. 5-8 illustrate a modified form of the antenna. In FIG. 5, the numeral 110 refers to a cellular telephone having a housing 112 and an antenna 114. The antenna 114 is electrically connected to the internal circuitry of the telephone through board contact 124. Antenna 114 includes a first metal connector element 118 adapted to be threadably mounted in the upper end of the housing 112 as illustrated in FIGS. 7 and 8. For purposes of description, connector element 118 will be described as having a lower end 120 and an upper end 122. Connector element 118 is RF connected to the circuitry within the cellular telephone by means of the board contact 124. Connector element 118 includes an elongated bore 126 extending therethrough.
The numeral 128 refers to an elongated housing comprised of a suitable dielectric material. As seen in the drawings, housing 128 includes a lower end 130 and an upper end 132. The lower end of housing 128 embraces and is secured to the upper end of connector element 118 as illustrated in FIGS. 7 and 8. The upper end of housing 128 has an opening 134 formed therein as will be described in more detail hereinafter.
A helical radiating element 136 is mounted in the interior of housing 128 and has its lower end in electrical contact with an upper contact 138 including an arcuate contact finger 139. The helical radiating element 136 is mounted on a coil form 140 as illustrated in FIGS. 7 and 8. The numeral 142 refers to a lower contact positioned within housing 128 and including an arcuate contact finger 144.
The numeral 146 refers to an elongated radiator, preferably comprised of nickel-titanium, having an upper end 148 and a lower end 150. A metal connector element 152 is secured to the lower end of radiator 146 as best seen in FIGS. 7 and 8. A dielectric body member 154 embraces radiator 146 above connector element 152 and has an upper end portion 156 which extends above the upper end 148 of the radiator 146. The upper end of the upper end portion 156 is provided with an enlarged head portion 158 which is provided to limit the inward movement of the antenna with respect to the housing 128. As seen in FIG. 9, a metal collar 160 embraces radiator 136 so that the radiator 136 will be in electrical contact with the contact finger 144 when the antenna is in its retracted position, as illustrated in FIG. 9. When the antenna is in the retracted position of FIG. 9, the sliding contact 160 will also be in electrical contact with the contact finger 140.
When the antenna is in the extended position of FIG. 7, only the elongated radiator 146 will be RF coupled to the telephone circuitry. Such RF connector is achieved through the board contact 124, connector element 118, connector element 152 and the radiator 146. When the antenna is in the extended position of FIG. 7, the helical radiator 136 is not in circuit.
When the antenna is moved from the extended position of FIG. 7 to the retracted position of FIGS. 8 and 9, the elongated radiator is not RF coupled to the telephone circuitry; However, in the retracted position, the helical radiator 136 is in electrical contact with the telephone circuitry. Such contact is achieved through the board contact 124, connector element 118, lower contact 142 (contact finger 144), sliding contact 160 and upper contact 138 (contact finger 140). When the helical radiator is in circuit when the antenna is in the retracted position of FIGS. 8 and 9, the upper end,portion 156 of dielectric body member 154 as illustrated in FIG. 8. When the antenna is in the retracted position of FIGS. 8 and 9, the elongated radiator 146 is positioned below the helical radiator 136. As also seen in FIG. 8, the upper end portion 156 of body member 154 is positioned within the helical radiator 136, when the antenna is in its retracted position, so that there will be no electrical interference between the elongated radiator 146 and the helical radiator 136.
Thus it can be seen that a novel telephone antenna has been illustrated in FIGS. 5-9. The embodiment illustrated in FIGS. 5-9 employs a switch that is actuated by sliding a cylindrical metal collar into two separate contacts. The switch of the antenna of FIGS. 5-9 is used to switch RF energy from a straight piece of wire to a helical long piece of wire. Further, the switch of the embodiment of FIGS. 5-9 is totally self-contained internal to the antenna and employs a self-cleaning switch. Thus it can be seen that the embodiment of FIGS. 5-9 achieves all of its stated objectives. | A retractable antenna for use with portable communication equipment comprising two electrically independent electromagnetic radiators in a single package with two modes of operation, retracted and extended. When the antenna is in its retracted position, a short normal-mode monofilar helical radiator is functional. When the antenna is in its extended position, a thin linear radiating element is functional. A switch is provided which connects the internal circuitry of the device to the linear radiating element when the antenna is in its extended position and which connects the internal circuitry of the device to the helical radiator when the antenna is in its retracted position. In each of the extended and retracted positions, the linear radiator and the helical radiator are isolated from one another. A modified form of the antenna is also disclosed. | 7 |
REFERENCE TO RELATED APPLICATIONS
This application claims the priority of German application Serial No. P 43 41 286.6, filed Dec. 3, 1993, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a rear frame for center pivot steered construction machinery, in particular for wheel loaders, wheel dozers, compactors, or the like, which, for receiving adjacent machine parts or subassemblies, is formed of components extending in the longitudinal direction of the frame and which can be connected with each other by means of further transversely extending components.
DE-C 29 05 528 relates to a vehicle, in particular a front-end loader, with at least one steering axle and pivotable rear wheels, and with a rigid frame composed of longitudinal and transverse beams which supports the vehicle body and the engine, has a center frame section extended downward between the wheels and essentially consists of an exterior frame part and an interior frame part partially extending between its lateral longitudinal beams, wherein the interior frame part extends portal-like over the rear wheels of the vehicle, and the interior frame part, comprising one or two longitudinal beams, extends between the axles of the front and rear wheels. In the area of the center frame section, both frame parts are disposed at the height of the floor of the driver's position. The engine is seated within the exterior frame part behind the rear wheels on the one side on supports at the back end of the interior frame part and on the other side on supports of the rear end of the exterior frame part. Even though this is not a center pivot steered construction vehicle, the arrangement of longitudinal and transverse beams is often employed in connection with such vehicles. In this case it should be noted as being disadvantageous that there results a quasi punctiform force introduction into the lateral frame walls on account of this lamella-like type of construction, which requires an appropriate dimensioning of the components to achieve the necessary rigidity of the frame. Furthermore it should also be noted as disadvantageous that it is necessary to provide a comparatively elaborate encapsulation of the engine because of the beam-type construction of the frame.
The object of the invention on the one hand is to reduce the weight of the components of the rear frame for optimizing the load distribution over the entire machinery as well as for simplifying of its handling during the manufacturing process and, on the other hand, to cause an optimized encapsulation of the drive assembly to improve the environmental compatibility of the machinery.
SUMMARY OF THE INVENTION
The above object generally is attained in accordance with the present invention in that the longitudinally extending components as well as those extending transversely thereto are embodied as surface elements which, when assembled, result in a basic structure allowing a linear integration of the structural parts in the form of a box which is closed or can be closed by machinery parts, adjoining subassemblies or similar components.
Advantageous further features of the subject of the invention ensue from the description of the invention and from the dependent claims.
In connection with the instant attainment of the object of the invention, a closed box, assembled from surface elements (plates), is selected as the basic structure of the rear frame. It is embodied in such a way that the introduction of exterior forces takes place at corners (bearings of the rear axle and driver's cab) or at edges (pivot hinge) of the box. The lateral surface elements extending in the longitudinal direction of the rear frame are embodied as bearing components analogous to those extending transversely. Based on the linear integration of all surface elements, all cross sections of the rear frame represent composite cross sections with a combined increased geometric moment of inertia. This allows a considerable reduction of the component weight by up to 25% with the same carrying capacity of the structure as well as the use of the same materials and application of the same production methods as with conventional structures formed of longitudinal and transverse beams.
The entire rear frame is furthermore designed in such a way that it encloses the drive assembly (transmission, converter, pumps, engine, etc.) of the construction machinery to the greatest extent and, where this is not the case or not possible, it is provided with level flange areas which permit a sealing connection of adjoining machine parts or subassemblies. Optimized sound proofing is achieved by means of this arrangement in comparison with the state of the art.
It is of further advantage that due to of its closed structure, the rear frame is used as a catch basin in case of leakage of the components disposed in it. Furthermore, because of the complete encapsulation, environmental effects are kept away from the drive train, besides a not inconsiderable lowering of noise emissions, so that under these circumstances it would be convenient to design the required lubrication points as lifetime lubrication, i.e. low maintenance or no maintenance, based on the service life of the construction machinery.
The surface elements of the rear frame take on a support functions as well as a casing function. Function-related openings in the surface elements of the rear frame are arranged in such a way that the support function of the surface elements is not hampered and that the openings can be sealingly closed with little effort. It is possible by means of suitable constructive measures to either avoid completely or to minimize structurally required openings for components extending from the interior of the rear frame into the open (cardan shafts, steering cylinders, hoses or the like).
As already described, it is possible because of the described design of the rear frame to reduce its structural weight considerably and to optimize the load distribution over the entire machine in this way. At the same time the outlay for casing parts for encapsulating the drive assembly is considerably reduced by the design of the rear frame without increasing its manufacturing expense.
An exemplary embodiment of the subject of the invention is shown in the drawings and will be described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a basic sketch of a center pivot steered wheel loader, together with a drive assembly, in the area of the rear frame,
FIG. 2 is a spatial representation of the rear frame in accordance with the invention of the wheel loader of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a center pivot steered wheel loader 1 essentially comprising a rear frame 2, a sketched pivot hinge 3, a driver's cab 4 fixed on the rear frame 2, a drive assembly formed by the engine 5, converter 6, transmission 7 and pumps 8, and an engine hood 9. The rear frame 2 is connected via the pivot hinge 3 with the front frame 10, only sketched in, on which a scoop 11 is fixed by means of a lifting mechanism, not shown in detail. Cardan shafts 12, 13 are provided at the output side of the transmission and are connected on the one hand with the front axle 14 and on the other hand with the rear axle 15 of the wheel loader 1. Furthermore, the rear frame 2 also receives the subassembly consisting of the hydraulic oil reservoir 16 and a counterweight 17. The structural design of the rear frame 2 of the center pivot steered wheel loader 1 is represented in FIG. 2.
FIG. 2 shows in a spatial representation the rear frame 2, embodied as a box comprised of flat side, front, rear and bottom plates, of the center pivot steered wheel loader 1 of FIG. 1, not shown in further detail here. The rear frame 2 consists of lateral surface elements 18, 19 extending in the longitudinal direction and of surface elements 20, 21, 22, 23, 24, extending transversely thereto in different horizontal and/or vertical planes and/or inclined with respect thereof and making possible a linear integration, as well as a rear wall 25. A flange 26 extending to a large degree around the top of the lateral surface elements 18, 19 is provided for receiving the driver's cab 4 of FIG. 1 and constitutes, with its front area 27, a portion of the pivot hinge 3, only sketched in here. In this case the free ends 28, 29 of the flange 26 are facing each other. The same holds true for the transversely extending surface element 21 disposed in the lower area of the lateral surface elements 18, 19, which forms an angle and constitutes a further part of the pivot hinge 3 in its front section 30. Further surface elements 31, 32 are welded to the front wall 20 in the area of the pivot hinge 3, and the pivot parts, not shown in detail, of the pivot hinge 3 are provided between the surface elements 27, 31 and 30, 32. The lateral surface elements 18, 19 as well as the surface elements 20 to 24 extending transversely thereto are provided with function-related openings 33, 34, 35, 36, 37, 38, 39, 40, 41, 42 (only indicated by way of example). The openings 33, 34 are used for maintenance purposes of the assemblies provided in the rear frame 2 and illustrated in FIG. 1, such as the hydraulic pump(s) 8 and the transmission 7. The openings 35, 36 can be provided for maintenance or diagnosing of the hydraulic control block of the wheel loader 1, the opening 37 for letting energy-conducting lines (for example hydraulic hoses) through to the front 10 of the vehicle, the openings 38, 41 for letting the cardan shafts 12, 13 through, and the opening 39 for receiving the converter 6. The further openings 40 and 42 have been cut into the associated transversely extending surface elements 21 and 24 for oil removal from the transmission 7 on the one hand and from the engine 5 on the other hand. In this case the openings 33 to 42 are disposed such that weakening of the cross sections surrounding them is assuredly prevented. Here, the lateral surface elements 18, 19 taper backwards from the pivot hinge 3 in the direction toward the rear wall 25, and the rear axle 15 is attached in the tapered area 43. Following the pre-assembly of the surface elements 18 to 25, the drive assembly shown in FIG. 1 and comprising the engine 5, converter 6, transmission 7 and pumps 8 is inserted as a connected component into the rear frame 2, still open at the top, and connected with the associated elements. Subsequently the subassemblies of, for example, the driver's cab 4, the hydraulic oil reservoir 16 and the counterweight 17, can be attached, wherein the driver's cab 4 is placed on the essentially circumferential flange 26 and in this way closes off the largest portion of the open area 44 located underneath. The hydraulic oil reservoir 16 directly adjoins the driver's cab 4 and is placed on the elements 28, 29 of the flange 26 as well as the shoulders 45, 46 of the lateral surface elements 18, 19 and is connected with them, so that a further area 47, open toward the top, is closed off. The remaining area 48 receiving the engine 5 is tightly closed by the engine hood 9, and lateral wheel boxes, not shown here, are bolted to the lateral surface elements 18, 19. The rear wall 25 is provided with a recess 49 open toward the top, in which the counterweight 17 is suspended, so that this area is also closed. Following assembly of the wheel loader 1, the remaining lateral openings 33 to 36, frontward oriented openings 37, 38 and downward oriented openings 40 to 42 can be sealingly closed by closure elements not further shown here, such as covers, fuel containers, cardan shafts or similar components, so that a box-shaped total structure encapsulated on all sides is formed. Besides a not inconsiderable noise reduction serving as an environmental protection, a possible outflow of leaking fluids is assuredly prevented by these means and the subassemblies located on the inside, such as the engine 5, the converter 6, the transmission 7, the pump(s) 8, cardan shafts 12, 13 or the like are protected from exterior environmental effects. Maintenance intervals can be extended which, in the long run, has positive results in the form of an increased availability of the machinery. To prevent further recesses which had been customary up to now, particularly in the area of the transversely extending surface element 20, for letting steering cylinders (not shown) through, a further component 50 is provided having eyes 51, 52 which are used for seating one end of the steering cylinders and the steering cylinders extend in the direction of the front 10 of the vehicle and are attached there to corresponding components.
The invention now being fully described, it will be apparent to one of ordinary skill in the art that any changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein. | A rear frame for center pivot steered construction machinery which, for receiving adjacent machine parts or subassemblies, is formed of components extending in the longitudinal direction of the frame and constitute bearing components which can be connected with each other by further transversely extending components. When assembled, the result is a basic structure in the shape of a box which is closed or can be closed by machine parts or adjoining subassemblies. | 4 |
TECHNICAL FIELD
[0001] The invention relates to a high-gradient magnetic filter for separating weakly magnetizable particles from fluid media, with the operating mode derived from the physical principle of generating field strength gradients by introducing a ferromagnetic structure into a magnetic field. The invention also relates to a method for operating the high-gradient magnetic filter.
[0002] Such filters predominantly generate the required magnetic field using permanent magnets, so that the components can be manufactured more compact and at lower cost, as well as operated more energy-efficient than filters using electromagnets.
STATE-OF-THE-ART
[0003] A device of this type has been described in DE 33 12 207 A1. The device includes stationary chambers that are filled with a magnetizable ferromagnetic filling material. Fittings are provided for feeding and discharging a fluid medium. Each pair of the chambers has a common magnetization arrangement, whose magnetic conductors includes two opposing elements that are arranged on different sides of a line extending through the centers of these chambers. Each of these elements includes a magnet with pole faces which are arranged on the chambers in diametrically opposed disposition in a direction perpendicular to the line extending through the centers of the chambers, whereby these two elements together with the ferromagnetic filling material form a closed magnetic circuit.
[0004] Disadvantageously, the device takes up considerable space and employs a complex process for separating the ferromagnetic substances from the fluid media.
[0005] DE 196 26 999 also discloses a high-gradient magnetic separator with a magnetic unit having two poles that together form a gap in which a homogeneous magnetic field can be generated, with a matrix frame that can be rotated about an axis and at least partially surrounds an annular interior space that is divided by partition walls into segments, as well as at least one feed and return line. It is an object of that invention to lengthen the path of the fluid within the magnetic field. This is solved in that the width of the magnetic unit along the interior space corresponds at least to the width of two segments and that each segment of the annular interior space is connected in the gap region with its adjoining segments through a respective opening, whereby the openings are located alternatingly at a first and a second location, wherein in the second location does not face the first location.
[0006] The magnetic field is herein also produced by permanent magnets, enabling a more compact design of the separator while lowering its manufacturing as well as operating costs.
[0007] Disadvantageously, the permanent magnets of this device cannot be switched off for the required backwashing operation. The filter chambers arranged in a carousel are therefore cyclically rotated out of the region of the magnetic field following the filtering operation, which takes place inside the magnetic field, and flushed in the field-free zone. Thereafter, the filter chambers are again rotated into the magnetic field and exposed to the fluid to be cleaned, until the filter is loaded and has to be backwashed again outside the magnetic field.
[0008] A carousel separator of this type is necessarily constructed with a large number of movable parts and, more particularly, numerous seals. This causes wear and leaks and can hence result in significant maintenance and repair costs which cannot be justified, for example, in a communal wastewater plant.
[0009] At least the problem caused by seals is solved by another high-gradient magnetic separator described in DE-GM 297 23 852.3. The individual filter chambers are here not moved in and out of the magnetic field. The filter system is stationary, and a magnet is mechanically moved back and forth for initiating the filtering process and backwashing. However, a large number of movable parts is still required.
[0010] Finally, a recently developed high-gradient magnetic separator, as described in WO01/07167 A1, is unsuitable for the problem to be solved, since it uses a different design and a different separation principle for the separation.
DESCRIPTION OF THE INVENTION
[0011] It is an object of the invention to provide a high-gradient magnetic filter for separating weakly magnetizable particles from fluid media, which—through the use of a permanent magnet for generating the magnetic field—represents a compact unit that can be easily maintained and repaired, which simplifies the process for separating the particles and renders the permanent magnet ineffective in the required backwash operation. The variety and number of components should also be reduced and the sealing problem eliminated. The method of the invention for operating the high-gradient magnetic filter should ensure an efficient use of the filter.
[0012] The object is solved with the invention according to claim 1 in that the high-gradient magnetic filter includes
[0013] a housing receiving the high-gradient magnetic filter with means for directing the fluid media in a pipe system with a feed and a return,
[0014] a magnetic circuit forming the actual high-gradient magnetic filter, with a filter disposed in a filter chamber that is formed between pole faces of the magnetic circuit, with the medium to be cleaned flowing through the filter,
[0015] at least one permanent magnet arranged in the magnetic circuit for generating the magnetic field between the pole faces, whereby this section of the magnetic circuit is separated from the fluid medium and therefore sealed, and
[0016] the magnetic field between the pole faces which can be switched off and switched on again by the permanent magnet.
[0017] The concept of the invention is further modified with the characterizing features of the claims 2 to 5 .
[0018] According to claims 6 to 8 or 9 , the invention can be functionally implemented in two different alternative embodiments.
[0019] According to one alternative embodiment, the permanent magnet is formed as a rotor and rotatably arranged in the correspondingly formed section of the magnetic circuit. The rotation angle of the rotor can be adjusted so that the field strength between the pole faces can be selected between a minimum and a maximum field strength value, so as to adapt the field strength to the different materials of the particles to be separated. It is also possible to lock the angular position of the rotor, for example, in steps of 90° or in steps having other angles.
[0020] According to the other alternative embodiment of the invention, the permanent magnet is formed as a linearly displaceable element in the correspondingly formed section of the magnetic circuit.
[0021] Advantageous embodiments of these alternative embodiments of the invention are recited as features of the claims 10 to 20 .
[0022] According to the method the invention for the operating the high-gradient magnetic filter according to the steps of claims 21 or 22 , the weakly magnetizable particles are separated from the fluid medium alternatingly in the pipe system essentially according to the following steps:
[0023] a) applying the fluid medium to be separated to the filter via the pipe system having a feed and a return while the magnetic field in the magnetic circuit between the pole faces is switched on, with the magnetic field penetrating the filter chamber of the filter containing the flowing medium, wherein the magnetic particles settle down on the filter due to the high field gradients, with the field strength being adjustable to different values that correspond to the angular position of the permanent magnet, thereafter
[0024] b) switching off the magnetic field of the permanent magnet and removing the settled and separated particles from the filter in a flushing process implemented as a counter-flow or also a co-flow process, and
[0025] c) repeating the step sequence a) and b) until the separation of the particles from the fluid medium is concluded.
[0026] The method can be implemented differently depending on the medium or media according to the features recited in claims 23 or 24 .
[0027] Moreover, the method according to claim 25 can also be operated efficiently by using a program for controlling the cycles of the fed and returned medium and/or flushing medium in cooperation with the magnetic field, which is to be switched on and off, and the magnetic field strength to be set, whereby the program also includes the functions of the features recited in claims 26 to 28 .
[0028] The invention will be described with reference to exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In the drawings,
[0030] [0030]FIG. 1 is a simplified diagram of the high-gradient magnetic filter in a state switched on by the rotor 10 ,
[0031] [0031]FIG. 2 shows the high-gradient magnetic filter of FIG. 1 in a switched-off state,
[0032] [0032]FIG. 3 is a schematic diagram of the alternative embodiment of the invention with the permanent magnet 9 embodied as a linearly displaceable element 11 ,
[0033] [0033]FIG. 4 is a schematic diagram of the rotor 10 with the permanent magnet 9 composed of individual permanent magnets 12 ,
[0034] [0034]FIG. 5 is a schematic diagram of the rotor 10 with a drive 13 ,
[0035] [0035]FIG. 6 shows schematically the support of the rotor 10 , and
[0036] [0036]FIG. 7 shows schematically a dual configuration according to the invention with two filters 8 and a rotor 10 .
BEST MODE FOR CARRYING OUT THE INVENTION
[0037] As shown in FIGS. 1 and 2, the high-gradient magnetic filter according to the invention is essentially constructed of a housing 1 with a pipe system having a feed 3 and a return 4 for directing a fluid medium 2 (arrows), from which weakly magnetizable particles are to be separated. Other means (not shown) are used for this purpose, such as, for example, conventional valve control blocks that control the corresponding feed 3 and return 4 of the medium 2 in alternating circulation directions.
[0038] A magnetic circuit 5 is disposed inside the housing 1 . A filter 8 , through which the medium 2 flows, is disposed in a filter chamber 7 formed between pole faces 6 of the magnetic circuit 5 . A permanent magnet 9 is arranged in the magnetic circuit, which produces in a switched-on state, shown in FIG. 1, between the pole faces 6 a magnetic field that extends through the filter 8 .
[0039] The entire section of the magnetic circuit 5 is always separated from the fluid medium 2 and therefore sealed, whereby the pipe system with the feed 3 and return 4 is surrounded by the magnetic circuit 5 in a compact manner.
[0040] [0040]FIGS. 1 and 2 shows the alternative embodiment of the invention with a permanent magnet 9 formed as a rotor 10 . The rotor 10 is provided with individual permanent magnets 12 , as shown in FIG. 4. FIG. 5 shows schematically a drive 13 for the rotor 10 , with the drive 13 being used to switch the magnetic field off (FIG. 2) and on (FIG. 1). Advantageously, the rotor 10 is provided with an axle 14 which is slidably and rotatably received in bearings 15 (FIG. 6).
[0041] [0041]FIG. 3 shows schematically the alternative embodiment of the invention with the permanent magnet 9 implemented as linearly displaceable, for example slidably supported, element 11 which switches the magnetic field on and off with the help of a drive (not shown). This high-gradient magnetic filter is constructed similarly to the filter depicted in FIGS. 1 and 2.
[0042] Advantageous embodiments of this basic construction are feasible which can be implemented depending on their intended application and desired efficiency, and which can be described as follows:
[0043] Depending on the characteristic properties of the weakly magnetizable particles to be separated from the fluid medium 2 , the rotation angle of the rotor 10 can be adjusted so that the effective field strength between the pole faces 6 can be selected between a minimum and a maximum field strength value. In this way, the field strength to which the different materials of the particles are subjected can be adjusted so as to affect the separation effect. Advantageously, the rotor 10 can also be rotated and locked in steps of 90° or in steps having other angles.
[0044] To increase the throughput and efficiency of the high-gradient magnetic filters according to the invention and to reduce their complexity, the embodiment depicted in FIG. 7 is proposed whereby the magnetic circuit 5 is implemented using two filters 8 and whereby a magnetic field produced by a permanent magnet 9 can in a switched-on state be applied simultaneously to each of the two filters 8 or switched off. FIG. 7 shows the permanent magnet 9 in form of a rotor 10 , whereby the throughput and efficiency can also be increased by the linearly displaceable element 11 implemented as a permanent magnet 9 , if the element 11 is compatible in a likewise configured and/or arranged magnetic circuit 5 and applies a magnetic field to at least two filters 8 .
[0045] The method of the invention for operating all the feasible alternative embodiments described in the claims 1 to 20 provides that separating the weakly magnetizable particles from the fluid medium 2 proceeds alternatingly in the pipe system according to the following steps recited in claims 21 to 24 :
[0046] a) In the first step sequence, the fluid medium to be separated is applied to at least one filter 8 via the pipe system. The pipe system can be alternatingly applied to a feed 3 and a return 4 , wherein in this first step sequence, for example, FIG. 1 depicts the feed 3 and return 4 of the fluid medium 2 to be cleaned, with the magnetic field in the magnetic circuit 5 between the pole faces 6 being switched on. The magnetic field penetrates the filter 8 through which the medium 2 flows via the pipe system. The filter 8 consists, for example, of a magnetizable wire mesh. Due to the high field gradients at the filter 8 , the magnetic particles settle down on the wire mesh. The field strength can be set to different values according to the rotation (rotor 10 ) or displacement (linearly displaceable element 11 ) of the permanent magnet 9 .
[0047] b) In the following step sequence, the magnetic field of the permanent magnet 9 (rotor 10 /linearly displaceable element 11 ) is switched off. The medium (or a medium) 2 with a feed 3 in the opposite direction and return 4 (e.g. corresponding to FIG. 2) removes the separated particles that settled down on the wire mesh of the filter 8 by flushing. Flushing can be carried out in several alternative ways, in that, e.g.,
[0048] a medium 2 to be cleaned or from which particles are to be removed is used as a flushing medium, or
[0049] a separate medium 2 is used as a flushing medium
[0050] by suitably directing the medium 2 in the pipe system through valve controls disposed in the feed 3 and return 4 .
[0051] c) Repeating the aforedescribed sequential steps continuously with circulation in opposite directions, whereby the filter 8 can be removed from the filter chamber 7 or exchanged depending on its condition or use, for example to replace the filter 8 .
[0052] Both alternatives can be implemented in a counter-flow (claim 21 b)) or in a co-flow configuration (claim 22 ).
[0053] By using a program according to claim 25 , the cycles of the forward and backward moving medium 2 and/or the flushing medium in the alternating circulation can be controlled for all alternative embodiments of the device and method in conjunction with the magnetic field, which is to be switched on and off, and the magnetic field strength to be set.
[0054] The method with the characterizing features recited in claims 26 to 28 can be adapted to the different applications of different complexity and design.
[0055] Industrial Applicability
[0056] The industrial applicability of the concept for the device and method is distinguished in that
[0057] on one hand, a compact unit requiring little maintenance and few repairs can be provided that has interchangeable assemblies for easy maintenance, and on the other hand, the process and operation of the separation of the particles from fluid medium can be performed easily and cost-effectively, whereby finally the aforedescribed disadvantages of the state of the art are successfully overcome so that many different and significant industrial applications become possible.
[0058] List of Reference Numerals
[0059] [0059] 1 =housing
[0060] [0060] 2 =fluid medium
[0061] [0061] 3 =feed
[0062] [0062] 4 =return
[0063] [0063] 5 =magnetic circuit
[0064] [0064] 6 =pole face
[0065] [0065] 7 =filter chamber
[0066] [0066] 8 =filter
[0067] [0067] 9 =permanent magnet
[0068] [0068] 10 =rotor
[0069] [0069] 11 =linearly displaceable element
[0070] [0070] 12 =individual permanent magnet
[0071] [0071] 13 =drive
[0072] [0072] 14 =axle
[0073] [0073] 15 =bearing
[0074] N=North pole
[0075] S=South pole | High-gradient magnetic filter and method for the separation of weakly magnetizable particles from fluid media ( 2 ) in a circuit, embodied as a compact, low-maintenance unit with low repair requirements, comprising a housing ( 1 ), for the high gradient magnetic filter, with means for directing the flowing medium ( 2 ) in a pipe system with a feed ( 3 ) and return ( 4 ), a magnetic circuit ( 5 ), forming the high-gradient magnet filter in which at least one filter ( 8 ) is arranged in a filter chamber ( 7 ), formed between the pole faces ( 6 ) of the magnetic circuit ( 5 ), through which the medium ( 2 ) for purification flows, at least one permanent magnet ( 9 ), arranged in the magnetic circuit ( 5 ), for generation of a magnetic field between the pole faces ( 6 ). The magnetic circuit ( 5 ) is separated and sealed off from the flowing medium, the magnetic field between the pole faces ( 6 ) may be alternately switched on and off by means of the permanent magnet ( 9 ), whereupon the discharge and the operation of separating off the particles from the flowing medium may be achieved simply and economically. | 1 |
RELATED APPLICATION
This is a continuation-in-part of copending application Ser. No. 752,041, filed Dec. 20, 1976 now abandoned.
BACKGROUND OF THE INVENTION
Various phosphorus compounds have been used as flame retardants with polymers such as polyurethanes. However, phosphorus compounds such as inorganic metal salts have been found difficult to apply or to retain in the polymer because of water solubility. Many of the organic phosphorus compounds are also volatile so that volatilization and exuding or bleeding of the compounds from the polymer occurs.
Another problem has been the formation of smoke since some phosphorus-organic compounds may reduce flammability, but cause considerable smoke evolution.
All organic based materials will burn, given proper conditions or proportions of heat and air. In recent years, plastic materials have found increasing use and many such materials pose a potential of fire wherever they are used.
Since polymers are organic materials, it would be impossible to make them non-combustible in all situations. Many additives and modifiers have been used to decrease the rate of burning and the spread of flame; however, most of the additives and modifiers so used are organic materials themselves which will burn under proper conditions. Many inorganic materials have also been used as flame retardants, but they are effective only when used in large amounts which are detrimental to polymer properties. Accordingly, known flame retardant additives, whether organic or inorganic, can be used in only small amounts or the physical properties of the polymer will be adversely affected.
The main cause of fire as a cause of death has been overlooked in the quest for better flame retardants. The problem of deaths caused by smoke inhalation remains.
It is not surprising that smoke reduction technology has not kept pace with flame reduction technology since it has seemed apparent to those skilled in the art that a system for reducing both smoke and flame would not be feasible. It was heretofore believed that smoke propagation was due to incomplete oxidation of the volatile products of pyrolysis and that smoke reduction could be achieved only by more complete oxidation, which inherently meant more flame. Conversely, increased smoke propagation was believed to be the natural and immutable consequence of flame reduction (i.e., reduced combustion).
Accordingly, there is a great need for polymer materials having reduced smoking characteristics, which are flame retardant, and which contain smoke and flame controlling additives in amounts insufficient to adversely affect the physical properties of the polymer.
SUMMARY OF THE INVENTION
The invention is based upon the combination of an organic polymer or resin together with an effective flame retardant amount of a halogenated phospholane oxide having the formula ##STR1## where X is chlorine or bromine;
m is a number from 2 to 4;
Y is oxygen or sulfur; and
R is an alkyl, aryl, alkoxy or aroxy group of 1 to 10 carbon atoms (the alkyl and aryl compounds are preferred). Polymeric phospholane oxides may also be used. These R groups are illustrated by alkyls such as, e.g., methyl, ethyl, propyl, butyl, hexyl, octyl; aryl groups such as, e.g., phenyl, tolyl, xylyl, naphthyl; alkoxy groups such as, e.g., methoxy, ethoxy, butoxy; aroxy groups such as, e.g., phenoxy, naphthoxy; and similar such radicals having from 1 to 10 carbon atoms.
The brominated phospholane oxides are made by conventional methods such as described in U.S. Pat. No. 2,663,739, from PCl 3 or RPCl 2 reacted with a diolefinic compound, followed by halogenation. Representative compounds are the chlorinated and brominated derivatives of 1-phenylphospholane-1-oxide and 1-ethyl-3-methyl-phospholane-1-oxide, and 1-phenoxyphospholane-1-oxide, and 1-ethoxyphospholane-1-oxide.
DETAILED DESCRIPTION OF THE INVENTION
The objectives of this invention are accomplished by providing combinations of organic polymers with the above halogenated phospholane oxides. The latter compounds may be incorporated into the components of the polymer such as in the manufacture of polyurethanes, or may be added from solution or by direct addition of the compounds per se to the organic polymer. In general, an effective flame retardant amount of the additive ranges from greater than 5% up to 50% by wt., based upon the weight of the final modified polymer.
The properties of a flame retardant component and those of a modified polymer containing such a substance are measured by a number of test methods. The "oxygen index" reflects data obtained in accordance with ASTM D2863-70 and is defined as the minimum concentration oxygen, expressed as volume percent, in a mixture of oxygen and nitrogen that will just support combustion under the conditions of the test procedure. The greater the oxygen index, the better the flame retardancy.
The NBS (Nat'l Bur. Standards) Smoke Density Chamber Test covers a procedure for measuring the smoke generated by solid materials. Measurement is made of the attenuation of a light beam by suspended particulate matter generated from materials under flaming combustion within a closed chamber. The resulting measurement is expressed in terms of the maximum specific optical density of the smoke (i.e. D m ).
Results of the test are given as a numerical value of D m f (flaming mode) and the time period in which D m occurs. The duration of the test is twenty minutes, or until D m is reached, whichever occurs first.
The relative efficiency of materials as smoke retardants is signified by a lower D m value over the duration of the test.
A detailed description of the test is given in the publication of the American Society of Testing Materials, ASTM STP No. 442 (1967).
The following examples illustrate specific embodiments of the invention, but are not limitative of the scope of the invention.
EXAMPLE 1
A polyurethane composition is prepared having the following formulation.
______________________________________ Parts byComponent Weight______________________________________Sucrose-based polyol, hydroxyl no. = 470(Multranol 4034, Mobay Chemical Co.) 50Blowing Agent (H.sub.2 O) 15.5n-Ethyl morpholine catalyst (WitcoChemical Company) 1.5Silicone (DC 193, Dow Corning Company) 0.8Polymethylene polyphenyl isocyanate, NCOeq. wt. = 131 (Mondur MR, Mobay ChemicalCo.) 701-methyl-3,4-dibromo-phospholane-1-oxide as the flame retardant 10______________________________________
The above formulation is used to prepare a modified polyurethane by heating. The polymer is employed in a smoke suppression test utilizing the procedure described above. The D m f is 98/2 min. The present phospholane oxide is also used in another polyurethane in an oxygen indext test with Estane, thermopolymeric polyurethane (B. F. Goodrich Company) as the substrate and with 10 wt. % of the phospholane oxide compound present. The oxygen index value is 25.3. Some scorching of the polymeric product occurs during the test. Similar flame and smoke results are obtained when the 1-methyl-2,3-dibromo phospholane-1-oxide additive is used.
EXAMPLE 2
A modified polyurethane is made using the following formulation:
______________________________________ Parts byComponent Weight______________________________________Sucrose-based polyol, hydroxyl no. = 470(Multranol 4034, Mobay Chemical Co.) 50Blowing agent (H.sub.2 O) 15.5n-Ethyl morpholine catalyst (WitcoChemical Company) 1.5Silicone (DC 193, Dow Corning Company) 0.8Polymethylene polyphenyl isocyanate, NCOeq. wt. = 131 (Mondur MR, Mobay Chemical Co.) 701-phenyl-2,3- dibromo-phospholane-1-oxideas the flame retardant 10______________________________________
The above formulation is used to prepare a modified polyurethane by heating. The polymer is employed in a smoke suppression test utilizing the procedure described above. The D m f is 80/4 min. The present phospholane oxide is also used in another polyurethane in an oxygen index test with Estane, thermopolymeric polyurethane (B. F. Goodrich Company) as the substrate and with 10 wt. % of the phospholane oxide compound present. The oxygen index value is 23.7. Some scorching of the polymeric product occurs during the test. Similar flame and smoke results are obtained when the 1-phenyl-3,4-dibromo-phospholane-1-oxide is used as the additive.
EXAMPLE 3
A polyurethane is prepared utilizing the following components.
______________________________________Component Parts by Weight______________________________________Polyether polyol (Pluracol GP-3030, 100Wyandotte Chemical Company)Blowing agent (H.sub.2 O) 4Triethylene diamine (Houbrey Chemical 0.65Company)Silicone (L-520, Carbide Chemical Company) 1Lead stearate 4Stannous octoate catalyst 0.16Tolylene diisocyanate 541-phenoxy-2,3-dibromo-phospholane-1-oxide 10as the flame retardant______________________________________
The above polyurethane resulting from the heating of the components set forth above is subjected to a smoke test. The D m f is 211/3 min. When the above phospholane oxide is used in an oxygen index test with a substrate of Estane (a thermo-polymeric polyurethane of B. F. Goodrich Company) the oxygen index value at 10 wt. % is 23.7.
When the above test is conducted with an 3,4-dibromo compound similar flame retardant properties are obtained.
In addition to above brominated phospholane oxides, the use of the chlorinated phospholane oxides also gives flame retardant properties with polymers, for example, in the use of the 1-butyl-2,3-dichloro-phospholane-1-oxide or the corresponding butoxy compound. The corresponding brominated compounds when used with an epoxy resin substrate such as Epi-Rez 510 made by Celanese Chemical Company, also improve the flame retardant properties.
Further halogenation is also effective as in 1-ethyl-2,3-,4,5-tetrabromo-phospholane-1-oxide, used as the additive in polymer modification.
EXAMPLE 4
Two polyurethane compositions (A and B) are prepared with the following components:
______________________________________ Parts By WeightComponent A B______________________________________1-phenyl-2,3-dichloro-phospholane-1- 20 20oxide as the flame retardantSucrose-based polyol, hydroxyl no. = 470 100(Multranol 4034, Mobay Chemical Co.)Amine based polyether polyol, 100hydroxy no. = 530, ave.M.W. = 480 (Poly-G-71-530,Olin Chemicals)Blowing agent (1 pt. H.sub.2 O, 30 pts. 31trichloromonofluoro-methane)Blowing agent (Trichloromonofluoro- 48methane)Amine catalyst, blend of triethylene- 3diamine (20%) and dimethylethanol-amine (80%) Dabco R-8020, Air Products)Dibutyltin dilaurate catalyst (Thermolite 0.312, M&T Chemicals)Silicone (DC-193, Dow Corning) 1.6 2Polymethylene polyphenyl isocyante, 140NCO eq. wt. = 131 (Mondur MR,Mobay Chemical Co.)Polymethylene polyphenyl isocyanate,NCO eq. wt. = 133.5 (PAPI 135, 143Upjohn Polymer Chemicals)______________________________________
The above polyurethanes resulting from the heating of the components set forth above are subjected to smoke tests and oxygen index tests as in Example 3 with the following results:
______________________________________ Smoke Test D.sub.m.sup.f Oxygen Index______________________________________Composition A 74 23.2Composition B 104 23.7______________________________________
Similar flame and smoke results are obtained when the 1-phenyl-3,4-dichloro phospholane-1-oxide is used as the flame retardant additive.
Results comparable to the above are obtained when the halogenated phospholane oxides of the present invention are incorporated in other resin systems, for example, methylmethacrylate, melamine/formaldehyde, vinyl halides and the like as described hereinafter.
Fire retardants incorporated in flexible urethane foam are often so volatile as to be unusable in practical applications. However, the compound dibrominated methyl phospholane oxide renders the foam self-extinguishing with only a slight increase in volatility. Ethylene glycol polyphosphate while self-extinguishing, is more volatile than this compound.
As illustrated, the compounds of the present invention are useful as flame retardants for a wide variety of natural and synthetic polymer materials. The compounds may be used in concentrations ranging from greater than 5 percent by weight relative to the total composition up to about 50 weight percent or more depending on the particular use for which the polymer material is intended.
Synthetic polymer materials, i.e., those high molecular weight organic materials which are not found in nature, with which the compounds of the invention are advantageously employed may be either linear or crosslinked polymers and may be in the form of sheets, coatings, foams and the like. They may be either those which are produced by addition or condensation polymerization.
An important class of polymers which are beneficially flame retarded with the compounds of the invention are those obtained from a polymerizable monomer compound having ethylenic unsaturation. A particularly preferred class of polymers which are flame retarded consists of the polymerized vinyl and vinylidene compounds, i.e., those having the CH 2 =C<radical. Compounds having such a radical are, for example, the solid polymeric alkenes, such as polyethylene, polypropylene, polyisobutylene or ethylene/propylene copolymers; polymerized acrylyl and alkacrylyl compounds such as acrylic, fluoroacrylic and methacrylic acids, anhydrides, esters, nitriles and amides, for example, acrylonitrile, ethyl or butyl acrylate, methyl or ethyl methacrylate, methoxymethyl or 2-(2-butoxyethoxy)ethyl methacrylate, 2-(cyanoethoxy)ethyl 3-(3-cyanopropoxy)propyl acrylate or methacrylate, 2-(diethylamino)ethyl or 2-chloroethyl acrylate or methacrylate, acrylic anhydride or methacrylic anhydride; methacrylamide or chloroacrylamide; ethyl or butyl chloracrylate; the olefinic aldehydes such as acrolein, methacrolein and their acetals; the vinyl and vinylidene halides such as vinyl chloride, vinyl fluoride, vinylidene fluoride and 1-chloro-1-fluoroethylene; polyvinyl alcohol; the vinyl carboxylates such as vinyl acetate, vinyl chloroacetate, vinyl propionate, and vinyl 2-ethylhexanoate; the N-vinyl imides such as N-vinyl phthalimide and N-vinyl succinimide; the N-vinyl lactams such as N-vinyl caprolactam and N-vinyl butyrolactam; vinyl aromatic hydrocarbon compounds such as styrene, alpha-methylstyrene, 2,4-dichlorostyrene, alpha- or beta-vinyl-naphthalene, divinyl benzene and vinyl fluorene; the vinyl ethers such as ethyl vinyl ether or isobutyl vinyl ether; vinyl-substituted heterocyclic compounds such as vinyl pyridine, vinyl pyrrolidone, vinylfuran or vinylthiophene; the vinyl or vinylidene ketones such as methyl vinyl ketone or isopropenyl ethyl ketone; vinylidene cyanide. Homopolymers of the above compounds or copolymers and terpolymers thereof are beneficially flame retarded by the compounds of the present invention. Examples of such copolymers or terpolymers are those obtained by polymerization of the following monomer mixtures; vinyl chloride/vinyl acetate, ethylene/vinyl chloride/vinyl acetate, ethylene/vinyl chloride, acrylonitrile/vinyl pyridine, styrene/methyl methacrylate, styrene/N-vinyl pyrrolidone, cyclohexyl methacrylate/vinyl chloroacetate, acrylonitrile/vinylidene cyanide, methyl methacrylate/vinyl acetate, ethyl acrylate/methacrylamide/ethyl chloroacrylate, vinyl chloride/vinylidene chloride/vinyl acetate.
Other polymers of compounds having the ethylenic group, >C═C<, are homopolymers, copolymers and terpolymers of the alpha-, beta-olefinic dicarboxylic acids, amides, nitriles and imides for example, methyl, butyl, 2-ethylhexyl or dodecyl fumarate or maleate; maleic, chloromaleic, citraconic or itaconic anhydride; fumaronitrile, dichlorofumaronitrile or citracononitrile; fumaramide, maleamide or N-phenyl maleamide. Examples of particularly useful polymers and terpolymers prepared from the alpha-, beta-olefinic dicarboxylic compounds are the copolymers of maleic anhydride and a vinyl compound such as ethylene, propylene, isobutylene, styrene, alpha methylstyrene, vinyl acetate, vinyl propionate, methyl isopropenyl ketone, isobutyl vinyl ether, the copolymers of dialkyl fumarate such as ethyl or butyl fumarate and vinyl compounds such as styrene, vinyl acetate, vinylidene chloride, ethyl methacrylate, acrylonitrile and the like.
The compounds of the invention act as flame retardants for the polymers and copolymers of unsaturated, cyclic esters of carbonic acid, for example, homopolymeric vinylene carbonate or the copolymers of vinylene carbonate with ethylenic compounds such as ethylene, vinyl chloride, vinyl acetate, 1,3-butadiene, acrylonitrile, methacrylonitrile, or the esters of methacrylic or acrylic acid.
Readily flame retarded by the compounds of the invention are also the polyarylcarbonate polymers such as the linear polyarylcarbonates formed from diphenols or dihydroxy aromatic compounds including single and fused-ring nucleii with two hydroxy groups as well as monohydroxy-substituted aromatic residues jointly in pairs by various connecting linkages. Examples of the foregoing include dihydroxy benzenes, naphthalenes and the like, the dihydroxydiphenyl ethers, sulfones, alkanes, ketones and the like.
The compounds of the invention also act as flame retardants for polymers, copolymers or terpolymers of polymerizable compounds having a plurality of double bonds, for example, rubbery, conjugated diene polymerizates such as homopolymerized 3-butadiene, 2-chlorobutadiene or isoprene and linear copolymers or terpolymers such as butadiene/acrylonitrile, isobutylene/butadiene, butadiene/styrene; esters of saturated di- or poly-hydroxy compounds with olefinic carboxylic acids such as ethylene glycol dimethacrylate, treithylene glycol dicrotonate or glyceryl triacrylate; esters of olefinic alcohols with dicarboxylic acids or with olefinic monocarboxylic acids such as diallyl adipate, divinyl succinate, diallyl fumarate, allyl methacrylate or crotyl acrylate and other diethylenically unsaturated compounds such as diallyl carbonate, divinyl ether or divinyl benzene, as well as the crosslinked polymeric materials such as methyl methacrylate/diallyl methacrylate copolymer or butadiene/styrene/divinyl benzene terpolymer.
The cellulose derivatives are flame retarded by the compounds of the present invention. For example, cellulose esters such as cellulose acetate, cellulose triacetate or cellulose butyrate, the cellulose ethers such as methyl or ethyl cellulose, cellulose nitrate, carboxymethyl cellulose, cellophane, rayon, regenerated rayon and the like may be flame retarded.
The compounds of the present invention are well suited for flame retarding liquid resin compositions of the polyester type, for example, the linear polyesters which are obtained by the reaction of one or more polyhydric alcohols with one or more alpha, beta-unsaturated polycarboxylic acids alone or in combination with one or more saturated polycarboxylic acid compounds, or the crosslinked polyester resins which are obtained by reacting a linear polyester with a compound containing a CH 2 ═C< group.
The compounds of the present invention are compatible flame retardants for epoxy resins. Such resins are condensation products formed by the reaction of a polyhydroxy compound and epichlorohydrin, which condensation products are subsequently cured by the addition of crosslinking agents. The hydroxy compounds may be, for example, ethylene glycol, 4,4'-isopropylidenediphenol and similar materials. The crosslinking agent employed in the curing step may be a dicarboxylic compound such as phthalic anhydride or adipic acid, but is more generally a polyamine such as ethylene diamine, paraphenylamine diamine or diethylene triamine.
Polyurethanes are a class of polymer materials which are flame retarded by the compounds of the present invention. The polyurethanes, like the above-mentioned polyesters, are materials which are employed in structural applications, for example, as insulating foams, in the manufacture of textile fibers, as resin bases in the manufacture of curable coating compositions and as impregnating adhesives in the fabrication of laminates of wood and other fibrous materials. Essentially, the polyurethanes are condensation products of a diisocyante and a compound having a molecular weight of at least 500 and preferably about 1500-5000 and at least two reactive hydrogen ions. The useful active-hydrogen containing compounds may be polyesters prepared from polycarboxylic acids and polyhydric alcohols, polyhydric polyalkylene ethers having at least two hydroxy groups, polythioether glycols, polyesteramides and similar materials.
The polyesters or polyester amides used for the production of the polyurethane may be branched and/or linear, for example, the esters of adipic, sebacic, 6-aminocaproic, phthalic, isophthalic, terephthalic, oxalic, malonic, succinic, maleic, cyclohexane-1,2-di-carboxylic, cyclohexane-1,4-dicarboxylic, polyacrylic, naphthalene -1,2-dicarboxylic, fumaric or itaconic acids with polyalcohols such as ethylene glycol, diethylene glycol, pentaglycol, glycerol, sorbitol, triethanolamine and/or amino alcohols such as ethanolamine, 3-aminopropanol, and with mixtures of the above polyalcohols and amines.
The alkylene glycols and polyoxyalkylene or polythioalkylene glycols used in the production of polyurethanes may by ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polythioethylene glycol, dipropylene glycol and the like.
Generally, any of the polyesters, polyisocyanate-modified polyesters, polyester amides, polyisocyanate-modified polyester-amines, alkylene glycols, polyisocyanate-modified alkylene glycols, polyoxyalkylene glycols and polyisocyanate-modified polyoxyalkylene glycols having three reactive hydrogen atoms, three reactive carboxylic and/or especially hydroxyl groups may be employed in the production of polyurethanes. Moreover, any organic compound containing at least two radicals selected from the group consisting of hydroxy and carboxy groups may be employed.
The organic polyisocyanates useful for the production of polyurethanes include ethylene diisocyanate, ethylidene diisocyanate, propylene-1,2-diisocyanate, m-phenylene diisocyanate, 2,4-tolylene diioscyanate, triphenylmethane triisocyanate, or polyisocyanates in blocked or inactive form such as the bis-phenyl carbamates of tolylene diisocyanate and the like.
Phenolic resins are flame retarded by the compounds of the present invention, which compounds may be incorporated into the phenolic resin either by milling and molding applications or by addition to film-forming or impregnating and bonding solutions prior to casting. Phenolic resins with which the present compounds are employed are, for example, the phenol-aldehyde resins prepared from phenols such as phenol, cresol, xylenol, resorcinol, 4-butylphenol, cumylphenol, 4-phenylphenol, nonylphenol, and aldehydes such as formaldehyde, acetaldehyde or butyraldehyde in the presence of either acid or basic catalysts, depending upon whether the resin is intended for use as a molding or extruding resin or as the resin base in coating and impregnating compositions.
Aminoplasts are another group of aldehyde resins which are flame retarded by the compounds of the invention. Examples of aminoplasts are the heat-convertible condensation products of an aldehyde with urea, thiourea, guanidine, cyanamide, dicyandiamide, alkyl or aryl guanamides and the triazines such as melamine,, 2-fluoro-4,6-diamino-1,3,5-triazine and the like. When the aminoplasts are to be used as impregnating agents, bonding adhesives, coating and in casting of films, the compounds of the present invention are incorporated into solutions or suspensions in which the aminoplast is carried. The resulting mixtures give strong, fire-retardant laminates when sheets of paper, glass, cloth or fabric are impregnated therewith and cured.
Another class of compounds which are flame retarded by compounds of the present invention are the nylons, for example, the superpolyamides which are generally obtained by the condensation of a diamine, for example, hexamethylene diamine with a dicarboxylic acid, for example, adipic acid.
Other polyamides which are flame retarded in accordance with the present invention are polypetides which may be prepared, for example, by reaction of N-carbobenzyl oxyglycine with glycine or mixture of glycine and lysine or an N-carboxy amino acid anhydride such as N-carboxy-DL-phenylalanine anhydride, piperidone, 2-oxohexamethyleneimine and other cyclic amides. The compounds of the present invention can be incorporated into molding or extruding compositions for a flame retarded effect.
The compounds of the present invention are also useful as flame retardants for linear polymers obtained by the self-condensation of bifunctional compounds, for example, the polyethers which are derived by the self-condensation of dihydric alcohols such as ethylene glycol, propylene glycol or hexamethylene glycol; the polyesters which are obtained by the self-condensation of hydroxy acids such as lactic acid or 4-hydroxybutric acid; the polyamides which are prepared by the self-condensation of aminocarboxylic acids such as 4-aminobutyric acid; the polyanhydrides which are formed by the self-condensation of dicarboxylic acids such as sebacic or adipic acid.
The preferred synthetic polymer materials which are flame retarded by the compounds of the present invention are the vinyl halide polymers in the form of milled products, plastisols and foams, rigid and flexible polyurethane coatings and foams, epoxy resins, ABS and GRS rubbers, aminoplasts and phenolics. The vinyl halide polymers can be simple, mixed homopolymers of vinyl chloride or polyvinylidene chloride, or copolymers or terpolymers in which the essential polymeric structure of polyvinyl chloride is interspersed at intervals with residues of other ethylenically unsaturated compounds copolymerizable therewith. The essential properties of the polymeric structure of polyvinyl chloride is retained if not more than about 40 percent of a comonomer is copolymerized therewith. Especially preferred copolymers include ethylene/vinyl chloride and vinyl chloride/acrylonitrile copolymers. Especially preferred terpolymers include ethylene/vinyl chloride/acrylonitrile, ethylene/vinyl chloride/acrylic acid and ethylene/vinyl chloride/acrylamide terpolymers.
Natural polymeric materials which may be flame retarded by the compounds of the present invention include natural rubber, cellulose esters, for example, cellulose acetate and cellulose nitrate, ethyl cellulose, cork and wood flour products and similar cellulosic materials.
The polymer formulations which are flame retarded in accordance with the present invention, whether in sheet or film form or of foam or molded structure, may contain various conventional additives such as fillers, extenders crosslinking agents and colorants. Minor amounts of stabilizers, for example, are usually incorporated to reduce the effects of heat and light.
When foamable compositions are used, the composition may be a self-blowing polymer or the polymer may be blown by chemical or mechanical means or by the use of compressed gas. Fillers which are frequently employed to lower the cost of the finished material and to modify its properties include calcium carbonate and magnesium silicate. When fillers are employed, they are generally present in an amount of up to about 150 parts by weight of filler per 100 parts by weight of polymer formulation.
Where a colored or tinted composition is desired, colorants or color-pigments are incorporated in amounts of from about one to about five parts by weight to 100 parts by weight of polymer.
Surfactants such as silicones are normally added to foam formulations which are mechanically frothed. The surfactants reduce the surface tension of the foam and thereby increase the air or gas entrapment characteristics of the foam.
Additionally, glass-forming inorganic materials such as zinc borate, zinc oxide, lead oxide, lead silicate and silicon dioxide may be added to decrease the flame and smoke generating characteristics of the polymer.
While the invention has been described by referring to certain specific embodiments, it is not so limited since many modifications and variations are possible in the light of the above teachings. The invention may therefore be practiced otherwise than as specifically described without departing from the spirit and scope of the invention. | The present invention relates to a process for the improvement of the flame retardant properties of a polymer composition which comprises incorporating therein an effective flame retardant amount of a halogenated phospholane oxide. The resultant products are useful as rigid or flexible foams and shaped articles having greatly improved flame retardant and smoke suppressant properties. The use of the halogenated phospholane oxide also imparts stability to the products, thus overcoming difficulties encountered with volatile phosphorus compounds which had been used heretofore with polymeric compositions such as polyurethanes. | 2 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
BACKGROUND OF THE INVENTION
This invention relates generally to fiber optic rotation sensors, and, more particularly to a fiber optic rotation sensor which is relatively unaffected by the environmental conditions surrounding it.
In the fields encompassing navigation, guidance and geophysical measurement, conventional gyroscopes leave much to be desired in their sensitivity in the measurement of rotation rates. In recent years, however, a dramatic development has taken place in optical technology with the invention of the laser gyroscope which is an example of a rotation sensor based on the Sagnac effect. The laser gyroscope combines the properties of the optical oscillator, the laser and general relativity to produce an integrating rate gyroscope. A good description of a laser gyroscope can be found in U.S. Pat. No. 4,013,365.
As pointed out in U.S. Pat. No. 4,013,365, the conventional laser gyroscope is a laser that has three or more reflectors arranged to enclose an area. The three reflectors, preferably mirrors, together with the light-amplifying material in the laser path, comprise an oscillator. In fact, there are two oscillators, one that has energy traveling clockwise and one that has energy traveling counterclockwise around the same physical cavity. The frequencies at which these oscillators operate are determined by the optical path length of the cavity they travel. In order to sustain oscillation, two conditions must be met: (1) the gain must equal to unity at some power level set by the amplifying medium, and (2) the number of wavelengths in the cavity must be an exact integer. If the first condition is to be achieved, the laser frequency must be such that the amplifying medium has sufficient gain to overcome the losses at the reflectors and the other elements in the laser path. In addition, the wavelength must be an exact integer for the path around the cavity. This last condition actually determines the oscillation frequency of the laser.
When the enclosed ring is rotated in inertial space the clockwise and counterclockwise paths have different lengths. The path difference in these two directions causes the two oscillators to operate at different frequencies. The difference is proportional to the rate at which the ring is rotating since path difference is proportional to inertial rotation rate. The readout of the gyroscope is accomplished by monitoring the frequency difference between the two oscillators.
Another rotation sensing device based on the Sagnac effect is the fiber ring interferometer of the type described in a publication by V. Vali and R. W. Shorthill in Applied Optics, Volume 15, No. 5, May 1976, pgs 1099 and 1100 in which a multi-turn fiber optic ring is used to increase the sensitivity of the device over earlier version of the Sagnac interferometer.
Even further substantially increasing the sensitivity of the fiber optic ring interferometer is the fiber optic rotation sensing interferometer of the type set forth in application Ser. No. 100,320, filed Dec. 5, 1979, now U.S. Pat. No. 4,323,310 issued Apr. 6, 1982, by Shaw et al, one of the inventors of this invention.
During utilization of the fiber optic rotation sensing interferometers of the past it was realized by the inventors of this invention that an important consideration in the practical operation of fiber optic interferometers for accurate rotation sensing at low rates is the fact that these interferometers or rotation sensors are environmentally sensitive. In other words, changes in temperature or strain in the fiber optic loop itself can result directly in errors in the measurement of rotation rates. Unless proper precautions are undertaken, optical non-reciprocity can occur in the optic fiber loop which renders the system environmentally sensitive. Consequently, it is essential in the utilization of fiber optic rotation sensors to eliminate this undesirable factor of environmental sensitivity.
SUMMARY OF THE INVENTION
The fiber optics rotation sensor of this invention overcomes the problems set forth in detail hereinabove by providing for a fiber optic rotation sensor which is relatively insensitive to surrounding environmental conditions.
The inventors have recognized that a basic consideration in the practical operation of fiber optic sensors for accurate rotation sensing at low rates is reciprocity in the rotation sensing loop. Under this principal, non-reciprocity in the operation of the loop renders the system environmentally sensitive, such that changes in temperature or strain in the fiber result directly in errors in the measurements of rotation rate. This refers to an environmental dependence of the basic Sagnac differential phase shift which is used as a measure of the rotation rate, and not to a simple systematic dependence of scale factor on temperature.
Generally, rotation sensing fiber optic sensors of the past have been operated without any control of relative polarization between input and output optical channels or with cross polarized input and output optical channels. These types of operations, it has been recognized by the inventors, are inherently sensitive to the surrounding environmental conditions. The utilization of cross polarized operation was attractive because it excludes, from the output, spurious interfering fringe patterns which are produced by reflections from the fiber ends in the input channel. In any system for rotation sensing based on the Sagnac effect it is phase splitting which provides the basic mechanism for measuring rotation rates. In the electrical fringe pattern phase splitting determines the number of fringes between the measured point and the starting point. If a change in phase shift experienced by either the clockwise or counterclockwise waves in the fiber (due to environmental conditions) produces any horizontal shift in location of the fringe pattern, then it can change its fringe count and produce a direct error in the measurement of rotation rate.
In order to overcome the problems of the past, the rotation sensor of this invention is operated in the co-polarized mode. This is accomplished by a conventional polarizer or polarization filter interposed within the electromagnetic beam both entering and leaving each end of the optic fiber loop within a fiber optic rotation sensor of the types, for example, as described in the cited Applied Optics article by Vali et al or U.S. Pat. No. 4,323,310 by Shaw et al. By the utilization of the co-polarized mode of operation as in the instant invention, no spurious shift in the fringe pattern is caused by a twisting of the optical fiber. The only effect is an amplitude change, however, this is unimportant as it need not lead to an error in rotation rate determination. Locations of zero crossings of the sinusoidal fringe pattern, which are the relevant quantities, are independent of amplitude.
In other words, when the fiber optic rotation sensor of this invention is operated in the co-polarized mode, the fiber optic loop behaves as a reciprocal element when the system is at rest, with identical total phase shifts for both clockwise and counterclockwise waves. When cross polarized operation takes place, as in the past, the resting phase shifts are not necessarily equal. The sensors heretofore in use would still be error free if the individual overall phase shift of the two waves were constant. However, in practice this does not occur since these overall phase shifts of the individual waves are strongly environmentally dependent. In fact, the strong phase sensitivity of an optical wave in a fiber to environmental effects is the basis of fiber optic temperature sensors, vibration sensors, strain gauges, acoustic transducers and the like. Consequently, the difference in the overall phase shift of the two waves, which is the quantity sensed in the conventional Sagnac interferometer, is also environmentally sensitive, unless the total phase shifts for both the clockwise and counterclockwise waves are identical.
The above phenomenon results from the fact that a fiber with a circular core is not in actuality a single mode waveguide, even though it can only support waves having a single basic transverse field pattern. It is in actuality a two mode system, in which the two modes are the two orthogonal polarizations of the basic transverse field pattern. It is this fact which leads to the non-reciprocal behavior when the system is improperly operated. The inventors have recognized that in such cases of cross polarizational use, the effects of non-reciprocity are sufficiently severe to render cross polarized operation unsatisfactory for systems designed for extremely high sensitivities and small rotation rates.
Unfortunately in overcoming the problem of environmental sensitivity, the co-polarized mode of operation of the rotation sensor of this invention increases interference from spurious fringe patterns. Therefore, for the rotation sensor of this invention to be properly operable, it is necessary to eliminate the back reflections from the fiber ends. Several approaches to eliminate this problem are possible. Solutions involve the utilization of such techniques as AR coating and liquid index matching. Another relatively simple expedient involves the beveling of the ends of the fiber by an appropriate amount. Although the particular method of removing these reflections may vary, it is essential within the fiber optic rotation sensor of this invention to remove reflections at the input side of the interferometer or sensor rather than the output side.
It is therefore an object of this invention to provide a fiber optic rotation sensor which is capable of providing high sensitivity in the measurement of rotation rates extending down to very low rates.
It is another object of this invention to provide a fiber optic rotation sensor which is independent of the surrounding environmental conditions.
It is still another object of this invention to provide a fiber optic rotation sensor which is economical to produce and which utilizes conventional, currently available components that lend themselves to standard mass producing manufacturing techniques.
For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.
DETAILED DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic representation of the fiber optic rotation sensor of this invention; and
FIG. 2 is an enlarged schematic representation of one end of the fiber optic loop of the fiber optic rotation sensor of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is now made to FIG. 1 of the drawing which schematically illustrates the environmentally independent fiber optic rotation sensor 10 of this invention. Rotation sensor 10 of this invention incorporates therein the main components of any conventional fiber optic rotation sensing interferometer based on the Sagnac effect and of the type described, for example, in the above cited Applied Optics publication. As additional components to the conventional fiber optic rotation sensing interferometer, the rotation sensor 10 of this invention incorporates therein a pair of conventional polarizers or polarization filters 12 and 14 located in a preselected position within the rotation sensor and adjusted to pass identical polarizations as well as means for removing undesirable reflections which are brought about as a result of the co-polarized adjustment of polarizers 12 and 14. Alternatively, a single polarization filter (not shown) could be substituted for polarization filters 12 and 14 in a manner described hereinbelow. The detailed description of the elements involved in the inventive concept of this invention will be set forth in detail hereinbelow.
Still referring to FIG. 1 of the drawing, rotation sensor 10 of this invention is schematically illustrated as being a system having a closed optical path 16 in which mechanical rotation introduces measurable shifts in the phase of the optical signal transversing closed path 16. Path 16 incorporates therein a multiplicity of distinct non-degenerate turns of a conventional optical fiber 18 thereby forming optic loop 20. The ends A and B of optic loop 20 are optically aligned with a pair of beams 22 and 24 of electromagnetic energy derived from a single beam 26 of electromagnetic energy emanating from any conventional electromagnetic source 28 such as conventional Nd; YAG or solid state lasers.
Coupling beams 22 and 24 to the ends A and B, respectively, of optic fiber 18 are a pair of conventional fiber couplers 30 and 32. Couplers 30 and 32 are generally in the form of lenses which enable the electromagnetic beams 22 and 24 to be coupled directly to the fiber optic loop 20. Division of the electromagnetic beam of energy 26 into the pair of beams 22 and 24 from laser 28 is accomplished by means of a conventional four port optical coupler in the form of, for example, a conventional beamsplitter 34 or a fiber optic or micro-optic directional coupler which is optically interposed between electromagnetic source 28 and couplers 30 and 32. Completing rotation sensor 10 is any conventional photodetector 36 which is optically aligned with the output beam 38 of electromagnetic energy from beamsplitter 34.
In the proper sequence of operation, beamsplitter 34 splits input beam 26 into the pair of beams 22 and 24 which are introduced into optical loop 20 by couplers 30 and 32. Beams 22 and 24 circulate in opposite directions about the optical path 16 of the rotation sensor 10 of this invention. A sampled beam 38 is directed to detector 36 by means of beamsplitter 34.
The two beams 22 and 24, in any coincident pair, have a mutual relative phaseshift of NΔφ 1 where Δφ 1 is the Sagnac phase splitting for one circulation around one turn of loop 20. Detector 36 measures the instantaneous relative phase shift between the two beams and provides an output determinative of the rotation.
In fiber optic rotation sensing interferometer of the type set forth in U.S. Pat. No. 4,323,310 by Shaw et al. the two beams in any coincident pair, have a mutual relative phaseshift of pNΔφ 1 where Δφ 1 is the Sagnac phase splitting for one circulation around one turn of loop, and p is the number of circulations corresponding to the beam in question. That is, the phase splitting for the pulse pair is NΔφ 1 at the one circulation, 2NΔφ 1 after two circulations, etc. Since for any rotation rate the phase splitting Δφ is now a function of time, the output of detector 36 will also be a function of time. The output of a phase/sensitive detector 36 receiving these beams will contain a term -c cos Δφ where c is a constant. Thus the output of detector 28 will contain a time sampled cosine waveform, whose envelope is a periodic function of time having a frequency which depends on the rotation rate. The detector measures the instantaneous relative phase shift between the two beams and provides an output determinative of the rotation.
The choice of whether to use two polarizers 12 and 14 as shown in FIG. 1 or a single polarizer (not shown) located in the path of beam 38 is dependent upon the specifics of the optical circuit. For example, in the cases where a fiber optic or micro-optic directional coupler is utilized as the beamsplitter with its terminals connected directly to fiber ends A and B (without lenses) then a single polarizer would be used. When a single polarizer is utilized it is necessary that the beam 26 be polarized.
The inventors have recognized that optic fiber rotation sensors of the past were sensitive to the surrounding environmental conditions wherein the changes in temperature or strain in the optic fiber 18 would result directly in errors in the measurement of rotation rate. This takes place since the environmental dependence of the basic Sagnac differential phase shift is used as a measure of rotation rate and not, for example, a simple systematic detection of scale factor on temperature. Therefore, unless proper precautions are taken, optical non-reciprocity can occur in optical loop 20 which renders the entire system environmentally sensitive.
It is important to point out that the basic circumstance which makes fiber optic rotation sensors operative is that both clockwise and counterclockwise signals transverse exactly the same path. This accounts for the fact that it is possible to form fringe patterns using these waves after they have traversed a length of path far exceeding the coherence length for either one of these waves taken individually. At the same time this circumstance makes it possible for those environmental changes which affect both waves reciprocally to be cancelled out in the output of the system, provided that the polarizations are properly attended to. This can be an important issue because of the very high sensitivity of an optical wave in a fiber to environmental effects.
The reason for the strong environmental sensitivity of an optical wave in a fiber is that very long, low loss, optical paths can be formed using fibers, for which the total phase shift can be extremely large, of the order of 10 9 cycles per kilometer. Thus, even weak environmental perturbations of the optical propagation velocity can result in large perturbations in phase shift. In a Sagnac interferometer, a rotation sensor for which these perturbations do not completely cancel, they can easily cause instabilities which mask the desired rotation signals. Generally, rotation sensors of the past have been operated in the cross-polarized mode in order to remove interfering fringe patterns, however, this simple and commonly used expedient for removing the interfering fringe patterns renders the system sensitive to environmental effects.
The instant invention sets forth a rotation sensor 10 which overcomes the problems of environmental instability by containing therein a pair of polarization filters, more commonly referred to as polarizers 12 and 14 located between each coupler 30 and 32, respectively, and beamsplitter 34. Polarization filters 12 and 14 pass the polarization of the input laser beams 22 and 24 and reject the cross-polarized waves. Such an operation is referred to as the co-polarized mode of operation and is at the heart of this invention.
In the instant invention, fiber optic rotation sensor 10 operates in the co-polarized mode with loop 20 behaving as a reciprocal element, with identical phase shifts for both clockwise and counterclockwise waves when rotation sensor 10 is at rest. In the cross-polarized mode of operation, as in the past, the resting phase shifts are not necessarily equal. As a result, the difference in the overall phase shift of these two waves, which is a quantity sensed in rotation sensing interferometers based on the Sagnac effect, is environmentally sensitive. This phenomena results from the fact that a fiber with a circular core is not really a single mode waveguide even thought it can only support waves having a single basic transverse field pattern. In actuality it is a two mode system in which the two modes are two orthogonal polarizations of the basic transverse field pattern. It is this fact which leads to the non-reciprocal behavior of the system when it is improperly operated.
Unfortunately, in the co-polarized mode of operation which eliminates this environmental sensitivity, as with rotation sensor 10 of this invention, spurious fringe patterns are not eliminated. To operate the instant invention without interference from such spurious fringe patterns it is necessary to eliminate back reflections from the ends A and B of fiber 18. This is a relatively minor consideration, but nevertheless constitutes a design complication representing a price which must be paid for system stability. In order to overcome this problem, rotation sensor 10 is capable of utilizing therein some of the readily available solutions to the problem in the form of such techniques as AR coating and liquid index matching. Another relatively simple expedient involves beveling the ends A and B of fiber 18 by an appropriate amount in a manner set forth hereinbelow. It should be realized that it is considered an important inventive feature to realize that the reflections must be removed from the input beams entering ends A and B of fiber 18 of rotation sensor 10 rather than from the output beams exiting ends A and B of fiber 18, in order to produce satisfactory results.
In order to eliminate the reflections referred to hereinabove, reference is now made to FIG. 2 of the drawing for a clear illustration of the angular design of fiber ends A and B. Since fiber ends A and B are identical, FIG. 2 only illustrates end A, however, it should be realized both ends A and B are beveled identically. Each end face (illustrated as A in FIG. 2) of fiber 18 is lapped and polished such that its normal 40 makes an angle of 29' with the axis 42 of fiber 18. The axis 44 of the beam traveling into fiber 18 from outside or exiting from fiber 18, is at an angle of 16° to the fiber axis 42. The axis 46 of the reflected waves 48 produced at the fiber/air interface makes an angle of 90° with the axis 44 of the input beam. The axis 44 of the beam entering of exiting fiber 18 makes an angle of 45° with normal 40 to the fiber end A. This angle is close to the 56% Bragg angle value for fiber 18 and very well within the broad transparent range in the vicinity of the Brewster angle.
For actual fiber lapping the section of fiber 18 near the ends A and B can be bonded into a small diameter capillary whose internal diameter approximately matches the outer diameter of the fiber cladding, and this capillary is in turn bonded into a tube whose outer diameter is easily handled for lapping and polishing to the proper angle as specified above. The entire assembly is mounted in a holder (not shown) which allows the fiber ends A and B to be adjusted in location and orientation, and holds couplers 30 and 32 at the correct angle with respect to the fiber axis 44.
Although this invention has been described with reference to a particular embodiment, it will be understood to those skilled in the art that this invention is also capable of further and other embodiments within the spirit and scope of the appended claims. | An environmentally independent fiber optic rotation sensor having a polarizer or polarization filter interposed between each beam coupler and the beamsplitter of the rotation sensor. The polarizers permit the passing of the polarization of the beams therethrough while rejecting the cross-polarized waves of the beams thereby causing a co-polarized mode of operation to take place. As a result of the co-polarized mode of operation the rotation sensor is unaffected by the surrounding environmental conditions. However, in so doing, the rotation sensor is subject to spurious fringe patterns which take place at the fiber ends. Elimination of these fringe patterns take place at the input side of the rotation sensor rather than at the output side in order to produce satisfactory rotation sensing. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an electric power steering system and, in particular, to a unit-type electric power steering system having compatibility allowing application to a variety of steering systems including manual steering mechanisms.
2. Description of the Related Art
An electric power steering system is known which comprises a torque sensor for sensing a steering torque and an electric motor designed to produce, in response to the sensed steering torque, a steering assist force to be supplied via a power transmission to the steered wheel side of a rack-and-pinion steering mechanism.
FIG. 8 is a block diagram illustrating the functional arrangement of a steering mechanism including such conventional electric power steering system. A torque sensor 102 is provided on a steering shaft for sensing a steering torque of a steering wheel 101. In response to the output of the torque sensor 102, a controller 103 controls an electric motor 104 and the engaging-disengaging action of an electromagnetic clutch 105, whereby a steering assist force is supplied via a power transmission 106 to a rack-and-pinion mechanism 107, which consists of a rack 107b and a pinion 107a, to steer steered wheels 108.
Since the conventional electric power steering system is closely associated with a steering system having an axially long rack shaft, a large space is required in a performance test conducted on the electric power steering system with such shaft before it is mounted to a vehicle. Further, since it is necessary to apply a large load on the rack shaft during the performance test, the equipment used for such test inevitably becomes large in size.
With desire to impart compatibility to a power steering system, attempts have been made to provide a unit-type power steering system capable of being separated from the steering system. The results of such attempts are disclosed in, for example, Japanese Patent Laid-Open Publication No. SHO 60-234069.
FIG. 9 is a block diagram of a steering system employing the conventional unit-type power steering system, and FIG. 10 is a longitudinal section of the conventional unit-type power steering system.
The power steering system 110 is disposed at a middle portion of a steering shaft 111 and supplies an assist force to a universal joint 112 to cause the rack-and-pinion mechanism 107 to perform a steering operation.
As shown in FIG. 10, the unit-type power steering system 110 includes a torque sensor 113 provided on an intermediate shaft 111a coupled to the steering shaft 111, and a housing 118 within which a controller 114, a motor 115, a clutch 116 and a power transmission 117 are accommodated in a unitized manner.
Due to its layout, the above power steering system is positioned within a steering column and projects radially of the middle portion of the steering shaft, thus reducing a space in front of the knees of a driver. Further, since it is located near the instrument panel, noise control is required so that the electrical equipment such as a car radio is not adversely affected. Moreover, since the power steering system is located distantly from the power supply, a long wire harness with large current capacity is needed. In addition, since it is located at the middle portion of the steering shaft, the power steering system may not be used with the steering shaft column for manual steering, which is connected with a steering shaft to present a large component, thus limiting its range of compatibility to power steering systems of the same type.
One might propose to provide a unit-assembled power steering system and to dispose it at the rack portion. However, this arrangement also requires the system to be formed as a unitary structure including the rack shaft housing, whereby the range of compatibility of the system is limited as in the above case.
The present invention was made with a view to avoid the foregoing inconveniences which present a bar to the formation of a unit-type electric power steering system.
It is therefore an object of the present invention to provide a unit-type power steering system which has a wide range of applications, including manual steering mechanisms, and hence has excellent compatibility.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a unit-type electric power steering system in which a steering torque of a rack-and-pinion steering mechanism is sensed and an electric motor is controlled to output, in response to the sensed steering torque, a steering assist force to be supplied to a pinion shaft so as to power-assist the movement of steered wheels, wherein a steering force input shaft and a pinion forming a final output shaft are formed in unitized relation with each other so that the electric power steering system can be removably attached to a rack shaft case for retaining a rack shaft.
In a specific form of the invention, the electric power steering system includes a torque sensor for sensing a steering torque, a motor, and a power transmission, which are formed in unitized relation with the pinion shaft of the steering mechanism. The electric power steering system also includes a controller, a housing, a transmission mechanism accommodated within the housing, an electric motor integrated with the housing, an input shaft having a main portion received within the housing and a shaft portion with an upper half projecting upwardly of the housing, and an output shaft having a main portion received in the housing and a pinion portion projecting downwardly of the housing.
The housing of the electric power steering system is provided with a first mounting flange at a lower end portion thereof. The rack shaft case includes a pinion case with a opening into which the pinion shaft is fitted. Around the periphery of the opening, there is provided a second mounting flange to be separably joined with the first mounting flange so that the rack shaft case and the electric power steering system also become unitary with the housing.
As is now apparent, in the present invention, the structural elements of the electric power steering system, such as the torque sensor, are connected in a unitized manner with the pinion shaft, whereby the system can be treated as a single unit member equivalent to a single pinion shaft. In addition, since it is as a unit and removably mounted to the rack shaft case, compatibility is provided between a universal joint on the steering wheel side and the rack shaft on the steered wheel side. Moreover, since changeover to and from a manual steering mechanism is enabled, the manual steering mechanism, designed as such, can be replaced later on with an electric power steering system, leading to a wide range of applications of the latter.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will hereinafter be described in further detail with reference to the accompanying drawings, in which:
FIG. 1 is a cross-sectional view taken longitudinally of an electric power steering system according to a first embodiment of the present invention;
FIG. 2 As an enlarged longitudinal sectional view of the main parts of FIG. 1;
FIG. 3 is an exploded perspective view showing a mode of attachment of a manual steering system and the electric power steering system, the manual steering system being shown by solid lines and the electric power steering system being shown by phantom lines;
FIG. 4 is a perspective view of a state in which the manual steering stem is attached to a rack shaft case;
FIG. 5 is a perspective view showing a state in which the electric power steering system is attached to the rack shaft case;
FIG. 6 is an enlarged longitudinal sectional view showing the main portions of the electric power steering system according to a second embodiment of the present invention;
FIG. 7 is a cross-sectional view taken along line 7--7 of FIG. 6;
FIG. 8 is a schematic perspective view illustrating the general arrangement of a conventional electric power steering system;
FIG. 9 is a schematic perspective view of the steering system employing a conventional unit-type power steering system; and
FIG. 10 is a longitudinal sectional view of the conventional unit-type power steering system.
DETAILED DESCRIPTION
Reference is initially taken to FIG. 1, in which an electric power steering system according to a first embodiment of the present invention is shown in longitudinal section.
The power steering system 1 is formed as a unit with a first shaft or pinion shaft 4 extending upwardly and downwardly of a housing 3, which supports a motor 2 in a unitized manner. The pinion shaft 4 has a torque sensor 5 for sensing an axe action torque or steering torque, and a power transmission 6 designed to transmit an assist force of the motor 2 to the pinion shaft 4.
The details of the power steering system 1 are as shown in FIG. 2. The pinion shaft 4 is comprised of a hollow input shaft 8 having a serration 7 provided in an upper portion thereof for fixing to a steering shaft, an output shaft 11 having a pinion 10 provided in a lower portion thereof for mated engagement with a second shaft or rack shaft 9, and a torsion bar 12 forming an elastic connecting portion interposed between the input and output shafts 8 and 11 for allowing the relative rotational operation of the input and output shafts 8 and 11.
The lower portion 8a of the input shaft 8 is rotatably connected to the output shaft 11 shown in FIG. 2 through an engagement portion 13 formed in the upper portion of the output shaft 11. In the hollow portion 14 of the input shaft 8, the torsion bar 12 is provided so as to penetrate into the hollow portion 14, and an upper end portion of the torsion bar 12 is fixed to the upper portion of the input shaft 8 with a pin 15. In a lower end portion of the torsion bar 12, a serration 16 is formed and fixed to the serration fit portion 11a of the output shaft 11.
The input shaft 8 of the pinion shaft 4 is journaled through a bearing 17 and an oil seal 18 with respect to the upper portion of the housing 3. The output shaft 11 is journaled in the lower portion of the housing 3 through a bearing 19.
The torque sensor 5 is comprised of a differential transformer 20 and includes a cylindrical slide member 21 slidably mounted on the outer periphery of the input shaft 8, and a ring-shaped, non-magnetic conductor member 21a provided on the outer periphery of the slide member 21. The slide member 21 includes a diagonal guide 22 between the input shaft 8, the guide 22 consisting of a groove 22a for guiding the slide member 21 in an angular direction at 45° with respect to a circumferential direction, and a pin 22b engaging with the groove 22a. The pin 22b is fixed to the input shaft 8 so as to project in a radial direction, and the groove 22a extends diagonally in the slide member 21.
Further, the slide member 21 has a longitudinal guide 23 between the output shaft 8, the guide 23 being consisting of an axial groove 23a, and a pin 23b engaging with the groove 23a. The pin 23b is provided in the upper end portion of the output shaft 11 so as to project in the radial direction, and the groove 23a is provided in the slide member 21. A spring 24 is disposed at an end portion of the slide member 21 at the output shaft 11 side for urging the slide member 21 in the direction of the input shaft 8 to thereby suppress the play in the axial operation of the slide member 21.
The steering input to the above input shaft 8 is transmitted to the output shaft 11 through the torsion bar 12, and the steering input to the output shaft 11 by the torsion bar 12 from the input shaft 8 and the relative displacement in direction of rotation to the input shaft 8 and the output shaft 11 are converted into the axial displacement of the slide member 21 by the engagement between the groove 22a and the pin 22b forming the diagonal guide 22.
On the other hand, the slide member 21 is allowed to displace in the axial direction by the engagement between the groove 23a and the pin 23b, that is, the slide member 21 is moved in the axial direction by the respective guides 22 and 23 in proportion to the relative rotational operation between the input shaft 8 and the output shaft 11. The above differential transformer 20 forms a torque sensor which outputs a signal corresponding to the magnitude and the direction of action of the torque acting on the input shaft 8.
The power transmission 6 is made up of a ring-shaped member 25 rotatably mounted on the outer periphery of the output shaft 11, and an advance-retract member 26. The ring-shaped member 25 consists of a large-diameter worm wheel, and, although not shown, it is constructed so that the output of the motor 2 is transmitted to the worm wheel 25 or to the output shaft 11 by the engagement between the worm on the rear side and the worm wheel 25 in FIG. 2, and the worm on the motor 2 side and the worm wheel 25 form a reduction mechanism.
Further, between the above ring-shaped member 25 and advance-retract member 26, an uneven tapered friction surface 27 is formed which uses a wedge effect to enable a torque to be transmitted by a small spring force, and the advance-retract member 26 is pressed by a spring 28 in the engagement direction. By this construction a torque limiter is formed which transmits a torque to the pinion 10 through a key 29 interposed between the output shaft 11 and the advance-retract member 26 while limiting an excessive torque.
In the above described power transmission 6, a compact reduction mechanism can be formed by the ring-shaped member 25. Also, the motor can be made small-sized. Further, by the clutch mechanism having the tapered friction surface 27, the whole system is made small-sized in addition to the miniaturization of the clutch and the simplification of a controller by the provision of the torque limiter for limiting the transmitted torque, whereby the unit can be handled more easily.
The lower half portion 30 of the housing 3 has a flange 32 forming the connecting portion for the rack shaft case 31, and the flange 32 has bolt holes 33 for attaching it to the mounting flange 31c of the rack shaft case 31, and a liquid-tight fit portion 34 for connecting the flanges 32 and 31c through a seal material 34a in a liquid tight manner. In the mounting flange 31c of the rack shaft case 31, there are provided bolt holes 31d corresponding to the above bolt holes 33.
With the above construction, the housing 3 is removably liquid-tightly fixed to the opening 35 inside the flange 31c of the rack shaft case 31, and the fit portion 36 forming the end portion of the output shaft 11 is now supported by a bearing 37 on the rack shaft case 31 side.
In the upper half portion 38 of the housing 3, a controller 39 for determining the steering assist force based on the output of the torque sensor 5 is integrally connected by means of a resin member. At a connecting portion 40 opposite from the lower half portion 30 of the housing 3, seal materials 40a are provided for liquid-tightly connecting the lower half portion 30 with the upper half portion 38. Further, the above controller 39 and the motor 2 are connected by means of a watertight plug 41.
The operation of the above power steering system is described below.
If the input shaft 8 is rotated from the steering shaft side, the torsion bar 12 is twisted, and the differential transformer 20 senses the axial displacement of the non-magnetic conductor member 21a which is caused by the relative rotational operation to the output shaft 11 and outputs a signal corresponding to the magnitude and direction of action of the torque. The controller 39 uses the output signal to determine the direction of rotation of the motor 2 and the magnitude of the torque according to the direction of action and magnitude of the above torque. Its output is doubled by the reduction mechanism of the ring-shaped member 25, and the torque is transmitted to the output shaft 11 while an excessive torque is limited by the torque limiter 26.
In the power steering system as constructed above, the torque sensor senses the steering torque and the assist torque is supplied to its output side by the ring member of the power transmission, and thus it has the function as an electric power steering only with the torque sensor.
Accordingly, by managing the characteristics of the sensor, the performance of the power steering system can be managed.
In the performance test of a power steering system, it has so far been needed to measure its output on the rack shaft of the steering system by the use of a high-load, large-stroke tester. In contrast to this, the power steering system of the present invention needs no long rack shaft and steering shaft since the main parts are collected in a unitized manner between the input and output shafts which are forming the pinion shaft, so that the tester can be made small-sized to reduce the testing space. In addition, since the power steering system of the present invention constitutes a compact unit, the space for storing it can be substantially reduced.
When the power steering system is built in a steering system, it is mounted as a pinion shaft unit by inserting the pinion 10 of its output shaft 11 into the opening 35 of the rack shaft case 31, superposing the flange 32 of the housing 3 on the flange 31c of the rack shaft case 31, and bolting the flanges 32 and 31c together. Further, the steering shaft side is fitted and fixed to the serration 7 of the input shaft 8.
Thus, a steering system equipped with the power steering system is completed between the universal joint shaft and the rack shaft, an assist force is supplied according to the torque acting on the steering wheel, and the rack shaft 9 moves in the axial direction to perform a steering operation.
Since the rack-and-pinion mechanism is positioned in the lower portion of the engine room when the power steering system related to the present invention is built in a vehicle, there is no effect on the space within the vehicle. In addition, since the power supply of a front-engine vehicle is positioned near the pinion shaft, the power supply connection is enabled by a short wire harness, the unit exchange can be performed in the same manner as the exchange of the pinion shaft for manual steering without removing the rack shaft or tie rod. Accordingly, the cost of replacement parts is suppressed, and the replacement work is done in a short time, so that repair and maintenance are easily performed.
Now, description is made to the compatibility between the manual steering system and the electric power steering system.
As described above, the case 31 of the rack shaft 9 slidably houses the rack shaft 9 in the axial direction, the large-diameter portion 31a is provided in a portion of the rack shaft case 31 which is near one end thereof, and on one side of the large-diameter portion, the vertically oriented pinion case 31b is integrally provided. The pinion case 31b has the opening 35 in the upper portion thereof.
On the rear end periphery of the opening 35 of the pinion case 31b, the outwardly expanding flange 31c is provided, and the flange 31c has the mounting screw holes 31d.
FIG. 3 is an explanatory perspective view showing the mounting relationships among the rack shaft 9 and the rack shaft case 31, a manual steering system 80, and the electric power steering system 1.
In the manual steering system 80, a gear mechanism, not shown, and the like are accommodated in a housing 85, and above the upper surface 85a of the housing 85, an input shaft 81 is projecting which has a serration 82 to be connected to the steering shaft, while a pinion 84 forming an output shaft 83 is projecting from the bottom surface of the housing. On the lower end periphery of the housing 85, there is provided a flange 86 corresponding to the above flange 31c of the pinion case 31b, and mounting holds 86a are formed in the flange 86.
FIG. 3 shows the state before the manual steering system 80 is attached to the rack shaft case 31, or the state in which it is removed. The power steering system 1 is shown by phantom lines.
FIG. 4 is a perspective view showing the state in which the manual steering system 80 is connected in a unitized manner to the flange 31c of the pinion case 31a of the rack shaft case 31 through the flange 86 of the housing 85 and by bolts 87 in the mounting holes 86a and 31d. The pinion 84 of the above output shaft 83 of the manual steering system 80 is inserted from the opening 35 into the pinion case 31b and engages with the rack shaft 9, and the steering input transmitted to the input shaft 81 is transmitted to the rack shaft 9 through the pinion 84 of the output shaft 83 to steer the steered wheel.
FIG. 5 shows the state in which the electric power steering system 1 related to the present invention is mounted to the pinion case 31b of the rack shaft case 31.
For the electric power steering system 1, the above flange 32 formed in the lower end portion of the housing 3 is superposed on the flange 31c of the pinion case 31b of the rack shaft case 31, and bolts 87 are inserted into the mounting holes 33 and 31d to couple the housing 3 to the pinion case 31b of the rack shaft case 31. The engagement between the pinion 10 of the output shaft 11 and the rack shaft 9 is as described above.
Thus, the manual steering system 80 and the electric power steering system 1 can be selectively mounted, and a wide range of compatibility is ensured.
The second embodiment of the present invention is now described. FIG. 6 is a longitudinal sectional view of the power steering system related to the second embodiment, and FIG. 7 is a sectional view along line 7--7 of FIG. 6; the members equivalent to the above described embodiment is assigned the same symbols and the pertinent description is omitted.
On the pinion shaft 52 of a power steering system 51, there are provided a torque sensor 53 for sensing the torque acting on the pinion shaft 52, and a power transmission 55 for supplying the assist force of a motor 54 to the pinion shaft 52.
The pinion shaft 52 consists of an input shaft 57 and an output shaft 58 which are rotatably connected to each other through a fit portion 56. The torque sensor 53 is provided on the input shaft 57, and the power transmission 55 is provided on the output shaft 58.
The torque sensor 53 has an arm-like rotary member 59 to form a variable resistor which outputs a signal corresponding to a rotation position. The rotary member 59 engages its end portion 59a with a recessed portion 60 provided in the top of the output shaft 58 and has a spring 61 for suppressing the play of the rotary member 59 in the direction of rotation, and outputs a signal according to the rotation position of the rotary member 59 by the relative rotational operation of the input shaft 57 and the output shaft 58.
The power transmission 55 comprises a planetary reduction mechanism 62 for decelerating and transmitting the rotation of the motor 54, a ring-shaped member 63 for further decelerating and outputting the decelerated rotation output, and roller-shaped transmission members 64 for transmitting the rotational force of the ring-shaped member 63 to the output shaft.
The planetary reduction mechanism 62 rotatably journals the output of the motor 54 by means of a plurality of balls, as described above, and has a carrier member making a retainer for retaining the balls an output.
In the above ring member 63, a bearing 65 is rotatably mounted on the outer periphery of the output shaft 58. A large-diameter hypoid gear 66a is formed on the outer periphery side of the ring-shaped member 63, and the hypoid gear 66a is provided integrally with the carrier of the planetary reduction mechanism 62. The hypoid gear 66a engages with a small-diameter hypoid gear 66b, which is slidably journaled on the output shaft 54a of the motor 54. A reduction mechanism is made up of the large-diameter hypoid gear 66a and the small-diameter hypoid gear 66b engaging with the gear 66a.
The inner peripheral side of the ring-shaped member 63 constitutes a circular supply-side transmission surface 67, as shown in FIG. 7. A substantially triangular output-side transmission surface 68 is provided opposite to the supply-side transmission surface 67 to form wedge-like spaces S between them. The wedge-like spaces S are formed for the respective peripheries of the output-side transmission surface 68, that is, three spaces are formed.
In each wedge-like space S described above, there are provided a pair of the transmission members 64 and a spring 69 for urging those transmission members 64 in the direction of engagement with both of the inner and outer surfaces, and an engagement/disengagement control member 70 is provided between the adjacent wedge-like spaces S for engaging and disengaging the transmission members 64, thereby to form a mechanical clutch. The engagement/disengagement control member 70 is connected in a unitized manner with the input shaft 57 and acts on the transmission members 64 according to the relative rotation between the input shaft 57 and the output shaft 58.
Between the input shaft 57 and the output shaft 58, a substantially rectangular projecting portion 71 is provided on the input shaft 57 side, and a similarly shaped recessed portion 72 is provided on the output shaft 58 side, so that a rotation engagement portion which fits with clearance in the direction of rotation is formed of the projecting and recessed portions 71 and 72. Spring receiving recessed portions 71a are provided on the left and right sides of the projecting portion 71 as shown in FIG. 7, spring receiving recessed portions 72a are provided on the opposing surface of the recessed portion 72, and elastic members 73 made up of a compression spring are interposed between the opposing surfaces of the receiving recessed portions 71a and 72a. The elastic members 73 allow the relative rotational operation between the input shaft 57 and the output shaft 58.
When the input shaft 57 is rotated, the elastic members 73 bend, and the engagement/disengagement control members 70 are rotated relatively to the output shaft 58. If the engagement/disengagement members 70 are rotated and retract from one wedge-like space, the transmission members 64 receiving the pressure of the spring 69 enter the corner portion of the wedge-like spaces. At this point, if the ring-shaped member 63 is driven in the same direction as the engagement/disengagement control members 70, the transmission members 64 are engaged between the supply-side transmission surface 67 and the output-side transmission surface 68 in the same corner, whereby one-way clutch is formed and the torque is transmitted.
In this case, when the ring-shaped member is reversely rotating or at rest, the transmission members 64 act in the direction in which the wedge-like spaces expand and are not engaged between both surfaces, and thus the torque transmission is interrupted and the output shaft receiving the torque of the input shaft through the elastic members 73 is manually rotated without receiving the reverse torque from the ring-shaped member.
If the load on the output shaft 58 side is particularly large, the projecting portion 71 and the recessed portion 72 of the rotation engagement portion abut on each other to transmit the input shaft torque, so that the excessive delay and torsion on the output shaft 58 side are avoided and the unnatural operation of the engagement/disengagement control members 70 and the elastic members 73 is prevented.
On the other hand, during the torque transmission, if the engagement/disengagement control members 70 are rotated in the direction of disengaging the engagement of the transmission members 64, the transmission members 64 are precluded from the corner portion of the wedge-like spaces by the operation of the engagement/disengagement control members 70 to interrupt the torque transmission even if the ring-shaped member 63 is rotated in an opposite direction with respect to the engagement/disengagement control members 70, so that the output shaft 58 operates following the operation of the input shaft 57 side without receiving the reverse torque.
In the unit-type electric power steering system constructed as above, the excessive delay in rotation on the output shaft 58 side and the unnatural operation of the engagement/disengagement control member 70 can both be avoided by its rotation engagement portion, and thus stable steering characteristics are ensured. Further, in the mechanical clutch employing the engagement/disengagement control members 70, the engagement/disengagement control members 70 caused to operate by the relative rotation between the input and output shafts 57 and 58 control the engagement and disengagement of the transmission members 64 in the wedge-like spaces S, so that the torque is transmitted to the output shaft 58 side only when the rotation of the torque supply shaft and the control direction of the engagement/disengagement control members 70 are in coincidence, and thus no load torque opposed to the operation of the input shaft 57 is received from the torque supply shaft side and torque control following the operation of the input shaft 57 is enabled. Accordingly, a compact unit-type electric power steering system can be formed as in the aforementioned embodiment.
Moreover, in the planetary reduction mechanism 62, the transmission force is limited by the slip of the balls rolling between the inner and outer rings when the excessive torque of the motor 54 is received, and it thus performs the torque limiter function.
As thus far explained in detail, in the present invention, the structural elements of the electric power steering system, such as the torque sensor, are connected in a unitized manner with the pinion shaft, so that it can be handled as a unit member corresponding to a single pinion shaft. Further, since it is a unit which can be mounted on and removed from the rack shaft case, compatibility is secured between the universal joint on the steering shaft side and the rack shaft on the steered wheels, so that it can easily be exchanged with a manual steering mechanism. Accordingly, the electric power steering system can be mounted in a steering mechanism designed for a manual steering mechanism, and it is widely applicable to steering mechanisms.
In addition, if the power transmission is formed of a ring-shaped member and provided with a reduction mechanism and a clutch mechanism, a compact reduction mechanism of a large reduction ratio can be obtained, and the motor can be made small-sized and the complex control load of the motor due to the restriction of the transmission torque can be avoided, whereby the unit is made small-sized and handled more easily. | A unit-type electric power steering system comprises a steering mechanism having a first shaft and a second shaft. The first shaft has an input shaft for connection to a steering shaft, and an output shaft connected to the input shaft for angular displacement relative thereto and for connection in driving engagement with the second shaft. The second shaft is disposed in a case for displacement therein. A torque sensor detects a steering torque of the steering mechanism, and an electric motor outputs a steering assist force to the first shaft in response to the steering torque detected by the torque sensor. The first shaft, the torque sensor and the electric motor define components integrated into a single unit for removable connection to and disconnection from the second shaft and the case as a single unit without independent connection and disconnection of any one of the components. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is filed under 35 U.S.C. §120 and §365(c) as a continuation of International Patent Application PCT/DE2007/000733, filed Apr. 25, 2007, which said application claims priority from German Patent Application No. 10 2006 023 806.0, filed May 20, 2006, which applications are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to a lever system for actuating a clutch, for example, a clutch in the power train of a motor vehicle or a brake, in particular a disc brake including a lever that is rotatably supported on one side about a pivot and the other side is in functional connection with a pressing means. The lever rests on a fulcrum on a runner unit that is displaceable in the radial direction by means of a motor-driven spindle and the runner unit rests on a raceway fixed to the housing and includes at least one roller set with runners.
BACKGROUND OF THE INVENTION
A generic clutch release system is known from the DE 10 2004 009832 document. FIG. 2 and FIG. 3 , explained further below, show an exemplary embodiment of a lever system according to prior art.
In solutions based on prior art, the introduction of torque to the axles or to the mounting points of roller set axles in a hub is disadvantageous.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to provide a lever system in which only small torque is introduced to the fixing point of roller set axles in a hub.
This object is met by means of a lever system for actuating a clutch, for example, a clutch in the power train of a motor vehicle or of a brake, in particular a disc brake comprising a lever, one side of which is rotatably supported about a pivot and the other side of which is in functional connection with a pressing means. The lever rests with one fulcrum on a runner unit displaceable in the radial direction and displaceable by means of a motor-driven spindle. The runner unit rests on a raceway fixed to the housing and at least includes a roller set with runners. The roller set comprises at least three runners, of which at least two runners feature a first diameter substantially equal and at least one runner that features a second diameter that differs from the first diameter. The terms first and second diameter are only chosen to distinguish between the two different diameters; which one of the two diameters is greater or smaller is not clarified by the terms first diameter and second diameter. Preferably, runners are disposed with approximately equal diameters on both sides of the runner with deviant diameter. Thus, runners with the first diameter rest on the lever and runners with the second diameter rest on the raceway. Preferably, runners with the first diameter rest on the lever and runners with the second diameter rest on the raceway. In that case, the first diameter can be the larger diameter and the second diameter the smaller diameter; the assignment can also be reversed. The roller set preferably comprises three runners. The two runners with approximately equal first diameter have a smaller diameter than the third runner. The preceding runner arrangement can also be reversed in principle, thus, it can be provided also that the roller set comprises three runners and the two runners with approximately equal first diameters have a larger diameter than the third runner. In one embodiment, the two runners with approximately equal diameters rest on the raceway and runners with the larger diameter rest on the lever. Preferably, the runners with the larger diameter engage with a section of the raceway. Owing to the engagement of the runner in the section, lateral guidance of the runner and thus of the roller set or of the entire runner unit is effectuated. In one embodiment, the two runners with approximately equal diameters comprise discs that project radially beyond runners and engage with the section of the raceway. The discs likewise bring about lateral guidance, in this case, a lateral guidance of the two runners with the smaller diameter. In one embodiment of the lever system according to the invention, the roller sets respectively rest loosely on an assigned idler roller that is disposed on an idler roller axle connected with the hub. The idler rollers bear the forces acting tangentially to the raceway; and the roller sets bear the forces acting in the normal direction to the raceway or in the normal direction to the lever. Advantageously, the normal forces do not generate torque on an axle of the roller sets. In one embodiment of the lever system according to the invention, the idler roller axle assigned to a roller set is connected with the respective axle of the roller set such that radial displacement of either towards one another is not possible. This connection can be executed, for instance, in the form of a cage that connects the respective idler roller axle with the respective axle. This arrangement corresponds functionally with a rod that connects the two axles with one another, where the two axles are mounted in a rotatable manner relative to the rod.
The problem mentioned above is solved by means of a runner unit for a lever system for actuating a clutch, for example, a clutch in the power train of a motor vehicle or of a brake, in particular a disc brake. The lever system comprises a lever that on one side is mounted rotatably about a pivot. The lever rests with one fulcrum on a runner unit displaceable in radial direction and displaceable by means of a motor-driven spindle. The runner unit rests on a raceway fixed to the housing and includes at least one roller set with runners. The roller set includes at least three runners, of which at least two runners feature approximately equal first diameters and at least one runner features a second diameter that is deviant from the first diameter. The problem mentioned above is also solved by means of a clutch release system for a clutch in the power train of a motor vehicle with a lever system according to the invention as well as a motor vehicle with a clutch release system for a clutch comprising a lever system according to the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Exemplary embodiments of the invention are explained in the following passage, based on the attached drawings. The figures are as follows:
FIG. 1 is a schematic depiction of a lever system according to the invention;
FIG. 2 is a side-view of a prior art runner unit;
FIG. 3 is a cross-sectional view along Section Z-Z in FIG. 2 ;
FIG. 4 is side view of a first exemplary embodiment of a runner unit according to the invention;
FIG. 5 is a cross-sectional view along Y-Y in FIG. 4 ;
FIG. 6 is an exemplary embodiment of a runners assembly according to FIGS. 4 and 5 ; and
FIG. 7 is a partial-sectional perspective view of an exemplary embodiment of a roller set.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a sketch of a disengagement system for actuating a clutch in the power train of a motor vehicle, between the engine and manual transmission. The principle of such a disengagement system is known from DE 10 2004 009832. Schematically depicted in FIG. 1 is a clutch 1 with a pressure plate 2 as well as a clutch disc 3 and a counterpressure plate 4 . To engage the clutch, pressure plate 2 on counterpressure plate 4 , non-rotationally connected with a crankshaft (not depicted), is pressed so that clutch disc 3 interposed between pressure plate 2 and counterpressure plate 4 is non-rotationally and non-positively connected with a transmission input shaft (not depicted). Pressure plate 2 is connected with a disc spring 5 , which is depicted only schematically as a spring. Disc spring 5 is connected with a lever 7 via a pressing means 6 . Pressing means 6 ensures that disc spring 5 is rotatably mounted in a known manner about a clutch axis 9 —the clutch axis 9 is the rotation axis—about which the clutch rotates in operation, which in normal cases coincides with the axis of transmission input shaft as well as the crankshaft axis. Thus, in as far as the arrangement corresponds to the arrangement described to date in DE 10 2004 009832 based on the example depicted in FIG. 1 and FIG. 2 for actuating a clutch. Lever 7 is mounted on the one side 7 . 1 of the lever with a housing bearing 8 capable of swiveling about an axis 8 . 1 that projects from the drawing plane of FIG. 1 ; on the other side 7 . 2 , it is connected with pressing means 6 . The housing bearing comprises a circular segment disc 16 , on which lever 7 is disposed so that fastening point 17 of the lever on circular segment disc 16 during rotation of the lever about axis 8 . 1 moves on a circular track. The connection between lever 7 and pressing means 6 can be formed such that radial displacement can occur based on clutch axis 9 . The radial displacement is necessary for compensation of a radial relative motion of lever 7 opposite to pressing means 6 during actuation of lever 7 . Lever 7 rests on a runner unit 10 that, as depicted in FIG. 1 of DE 10 2004 009832, for instance, consists of an arrangement of rollers which can be disposed in form of a triangle, wherein one of the rollers is in contact with lever 7 and the two other rollers rest on one essentially plane raceway 11 . In one embodiment, the raceway is fixed to a housing (not shown). For simplicity, runner unit 10 is depicted here as a circle. Runner unit 10 rests on lever 7 in a displaceable fulcrum 12 . Fulcrum 12 is displaced during displacement of runner unit 10 along a curved track 13 . Curved track 13 is formed by the side of lever 7 facing the runner unit 10 . Lever 7 in this respect, according to the sketch of FIG. 1 , can be a rod or a disc with essentially constant thickness, however, it can likewise feature another arbitrary form, so that, for instance, curved track 13 features a form different from the side of lever 7 facing away from runner unit 10 . Runner unit 10 is displaceable via a spindle 14 by means of an electric motor 15 , rigidly mounted on the housing, in a radially displaceable manner relative to clutch axis 9 along the coordinate x. If runner unit 10 is displaced along the raceway 11 , in one of the two directions specified by coordinate x, then the axial point of pressing means 6 changes (based on clutch axis 9 ). For the axial point of pressing means 6 , a coordinate y is drawn in FIG. 1 ; for the radial point of runner unit 10 , coordinate x is drawn accordingly. Zero points of both coordinates are first arbitrary; for coordinate x, the radially furthest, outwardly displaced point of rest point 12 of runner unit 10 can be assumed as zero point, for instance. This point is outlined in FIG. 1 by means of a dashed line with designation x o . A point y o of pressing means 6 belongs to point x o of runner unit 10 or of rest point 12 . Should value x and hence the point of runner unit 10 be increased from value x o in the direction of coordinate x, then pressing means 6 , starting from the direction of the coordinate, will be moved from a zero point y o , at the same time, pressure plate 2 will be moved towards counterpressure plate 4 , thus, the clutch will be connected. Point x o of runner unit 10 in the present exemplary embodiment designates the disconnected point of the clutch. This therefore involves an actively pressed clutch. In principle, it is also possible in the same manner to operate a clutch to be disconnected actively, when it is connected at rest and is not yet disconnected.
FIG. 2 and FIG. 3 show a principle sketch of a disengagement system according to the prior art in FIG. 1 in further abstracted depiction. Lever 7 is rotatably mounted with housing bearing 8 . Runner unit 10 is connected with spindle 14 by means of a mount hub 18 . Mount hub 18 comprises an axis 19 , which, as is apparent in the depiction of FIG. 3 , comprises two axles 19 . 1 and 19 . 2 disposed on both sides of mount hub 18 and for instance screwed or welded together with said axles. Roller sets 20 . 1 or 20 . 2 are respectively disposed on axles 19 . 1 and 19 . 2 . Roller sets 20 . 1 and 20 . 2 respectively comprise a runner with large diameter 21 and a runner with small diameter 22 . The runner with large diameter 21 rests on lever 7 , runner 22 with small diameter rest on raceway 11 . Raceway 11 has a width b, which is dimensioned such that it is wrapped around by runners with larger diameter 21 of roller sets 20 . 1 and 20 . 2 . The runners with larger diameter 21 wrap around raceway 11 and thus provide lateral guidance of roller sets 20 . 1 and 20 . 2 and thus of the entire runner unit 10 . Lever 7 rests respectively on runners 21 , the entire runner unit 10 rests on raceway 11 via runners with smaller diameter 22 . Clutch force Fy causes a corresponding normal force F N in fulcrum 12 through the lever arm ratios between fulcrum 12 and the action of clutch force Fy or of the lever between fulcrum 12 and fastening point 17 . Assuming symmetrical geometrical dimensions, F N /2 acts respectively on runners with large diameter 21 and the corresponding counteractive force of F N /2 on runners with small diameter 22 . Thus, torque is generated about fastening points 23 of axles 19 . 1 and 19 . 2 with mount hub 18 .
FIGS. 4 to 6 show an exemplary embodiment of a lever system according to the invention or a runner unit 10 according to the invention. On the housing side, lever 7 rests on a housing bearing 8 . Runner unit 10 is moved by a spindle 14 and rests on a raceway 11 . The type of depiction otherwise corresponds essentially to the depiction of FIG. 2 .
FIG. 5 shows a section according to Y-Y in FIG. 4 . Runner unit 10 comprises two roller sets 20 . 1 and 20 . 2 that rest on idler rollers 25 . 1 and 25 . 2 , which are connected with idler roller axles 26 . 1 and 26 . 2 with mount hub 18 . Roller sets 20 . 1 and 20 . 2 are therefore not directly connected with mount hub 18 and comprise respectively a runner with large diameter 21 , which rest on lever 7 . A runner with small diameter 22 . 1 and 22 . 2 is disposed respectively on both sides of runners with large diameter 21 . In FIG. 5 is the runner with small diameter, which is disposed between the respective runners with large diameter 21 and mount hub 18 , is provided with reference sign 22 . 2 ; the runner with small diameter, which is disposed on the runner with large diameter 21 facing away from mount hub 18 , is provided with reference sign 22 . 1 . The runners with small diameter 22 . 1 and 22 . 2 respectively rest on raceway 11 . Raceway 11 includes two cutouts 24 , which as depicted in FIG. 5 run perpendicularly to the drawing plane. The runners with large diameter 21 of two rollers sets 20 . 1 and 20 . 2 will engage with cutouts 24 . When a force F N /2 is exerted as compressive force by lever 7 on one of runners with large diameter 21 , then a counteractive force F N /4 will be exerted by the two respectively assigned runners 22 . 1 and 22 . 2 of respective roller set 20 . 1 or 20 . 2 . This is depicted in the example of roller set 20 . 1 in FIG. 5 . Apart from a deflection of axles 19 . 1 or 19 . 2 , on which the respective roller sets 20 . 1 or 20 . 2 are connected with mount hub 18 , no torque will be exerted by the normal force F N arising from clutch force Fy on fastening points 23 . Cutouts 24 in raceway 11 provide a two-side guidance of roller sets 20 . 1 or 20 . 2 , since runners with large diameter 21 respectively engage with same, so that the runner with large diameter 21 partially projects into section 24 as is apparent in FIG. 5 .
FIG. 6 shows a section according to X-X in FIG. 4 . Roller sets 20 . 1 and 20 . 2 do not rest directly on mount hub 18 , but support themselves on idler rollers 25 . 1 and 25 . 2 , which are connected by idler roller axles 26 . 1 and 26 . 2 with mount hub 18 . Axles 19 . 1 and 19 . 2 are therefore not connected directly with mount hub 18 . Through the geometry of lever configuration, a clutch force Fy, a normal force F N , and a tangential force F T , as they are marked in FIG. 4 , are constantly exerted on runner unit 10 . Force F T is also outlined in FIG. 6 . Through tangential force F T , roller sets 20 . 1 and 20 . 2 , on which tangential force F T respectively act on the parts, are pressed against idler rollers 25 . 1 25 . 2 . In addition (not shown), axle 19 . 1 , for instance, can be connected with support axle 26 . 1 and axle 19 . 2 as well with support axle 26 . 2 , e.g., in form of a cage 29 . Half-tangential force F T /2 acts on either idler roller 25 . 1 or 25 . 2 respectively—when disposed symmetrically on spindle 14 . The preceding arrangement produces the only torque in fastening points 23 .
Runners with small diameter 22 . 1 and 22 . 2 and axis 19 on which they are located and axle 19 . 1 for roller set 20 . 1 and axle 19 . 2 for roller set 20 . 2 can be connected firmly, e.g., by either pressing or welding. The runner with large diameter 21 of respective roller set 20 . 1 or 20 . 2 is rotatably supported relative to respective axle 19 . 1 or 19 . 2 , so that runners with small diameter 22 . 1 and 22 . 2 are not rotatable about their own respective axis. However, the runners with small diameter 22 . 1 and 22 . 2 are rotatable relative to the runner with large diameter 21 of the respective roller set 20 . 1 or 20 . 2 . In principle, this arrangement can also be reversed, in that, the respective axle is firmly connected with the runner with large diameter 21 and runners with small diameter 22 . 1 and 22 . 2 are rotatably disposed relative to the axle.
FIG. 7 shows an exemplary embodiment of a roller set 20 . 1 or 20 . 2 in a three-dimensional depiction, in partial section. Axis 19 is pressed together with runners with small diameter 22 . 1 and 22 . 2 . A needle bearing 27 is disposed between runners with small diameter 22 . 1 and 22 . 2 , which carry the runner with large diameter 21 . In the exemplary embodiment of FIG. 7 , runners with small diameter 22 comprise discs 28 respectively on the side facing the runner with large diameter 21 , which engage with cutouts 24 and take over lateral guidance of the respective roller set 20 . 1 or 20 . 2 .
REFERENCE SIGN LIST
1 clutch
2 pressure plate
3 clutch disc
4 counterpressure plate
5 disc spring
6 pressing means
7 lever
7 . 1 , 7 . 2 side of the lever
8 housing bearing
9 clutch axis
10 runner unit
11 raceway
12 fulcrum
13 curved track
14 spindle
15 electric motor
16 circular segment disc
17 fastening point
18 mount hub
19 axis
19 . 1 , 19 . 2 axles
20 . 1 , 20 . 2 roller sets
21 runner with large diameter
22 , 22 . 1 , 22 . 2 runner with small diameter
23 fastening point
24 section
25 . 1 , 25 . 2 idler rollers
26 . 1 , 26 . 2 idler roller axles
27 needle bearing
28 discs
29 roller cage
X actuation distance of actuator
Y actuation distance of clutch
Fy clutch force
Fx actuating force
F N normal force
F T tangential force | A lever system for actuating a clutch in the power train of a motor vehicle or of a disc brake, including: a lever ( 7 ) with a first side ( 7.1 ) rotatably supported on a pivot ( 8 ) and with a side ( 7.2 ) in functional connection with a pressing means ( 6 ). The lever ( 7 ) rests on a movable fulcrum ( 12 ) provided by a moveable support unit ( 10 ) that is displaceable in radial direction relative to the rotation axis of the clutch or the disc brake and which is displaceable using a motor-driven ( 15 ) spindle ( 14 . The moveable support unit ( 10 ) rests on a raceway ( 11 ) and includes two roller sets ( 20.1, 20.2 ) each with rollers ( 21, 22, 22.1, 22.2 ). Each of the roller set ( 20.1, 20.2 ) includes at least three rollers ( 21, 22, 22.1, 22.2 ) and at least two of the rollers ( 22.1, 22.2 ) include approximately equal first diameters. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for detecting foreign bodies such as foreign fibers, tying strings, bands of synthetic material, wire pieces and the like within or between textile fiber tufts, particularly cotton and/or synthetic fiber tufts.
In practice undesirable foreign fiber materials may be found within a cotton or synthetic fiber mass which, to a significant degree, adversely affect the making of high quality yarns. The foreign fiber material frequently remains in the mass of useful fibers after processing in the cleaning and spinning installations and, among others, disadvantageously leads to colorings. In many instances, the impurities are jute, kemp or polypropylene strings or bands. The foreign fibers originate mostly from packaging and from sacks which had been utilized during harvest.
Foreign fibers, tying strings or the like can be found in practice frequently in the pressed fiber bales. The pressed-in strings extend often through several layers (zones) so that it is frequently necessary to manually dig deeply into the bales for removing the entire string or band. Proceeding in this manner is very time-consuming and adversely affects the continuous fiber processing.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved detecting apparatus which, in particular, makes possible a reliable spotting and simple removal of foreign bodies, particularly foreign fibers.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fiber tufts are arranged in a loose layer and a foreign body detecting device and the loose fiber tuft mass are moved relative to one another.
By providing a loose fiber tuft mass, the foreign bodies are not embedded firmly in the inside of the mass as it is the case in a pressed fiber bale but are arranged loosely within or between fiber tufts and, also because of the small height of the loose fiber layer, are easily detectable. Further, the foreign bodies are, because of the loose layer, easily accessible which makes possible a simple removal thereof.
The foreign bodies, particularly threads, strings and the like differ from the fiber tufts in that they are relatively long and slender. By virtue of the fact that the opened fiber tufts are arranged in a loose layer and that an apparatus is provided which can detect the foreign bodies, that is, the foreign bodies may be recognized from the exterior, there is achieved a reliable recognition so that a differentiation and removal of the foreign bodies from the fiber tufts is made possible. Preferably, a conveyor belt is provided on which the fiber tuft layer moves relative to the stationarily arranged detecting apparatus. Expediently, the conveyor belt is a sieve belt which is exposed to suction. According to a further feature of the invention a fiber tuft supplying device is arranged upstream of the conveyor belt. Preferably, the detecting device ascertains the configuration and/or the color and/or the size and/or the brightness of the foreign bodies. Advantageously, the detecting apparatus has a transmitted and a receiver for electromagnetic waves or rays. Expediently, the apparatus is a picture-taking device such as a television camera. Advantageously, the apparatus is an X-ray device. Preferably, an image memory receives signals from the detecting device. Preferably, an evaluating device receives signals from the image memory for distinguishing the foreign bodies from the fiber tufts. Expediently, downstream of the evaluating device there is arranged an apparatus for removing the foreign bodies. Expediently, between the evaluating device and the apparatus for removing the foreign bodies a switching device is arranged. Advantageously, the apparatus according to the invention is situated immediately downstream of the bale opener which removes fiber tufts from the textile fiber bales.
Expediently, the fiber tufts removed from the fiber bales by the bale opener are placed on a belt by an at least approximately uniform spreading operation. The belt may be a conveyor belt whereby a thin layer of fiber tuft mass may be obtained. Such thin layer is, during conveyance thereof, monitored by an optical system, for example, a camera. Pictures are produced which are electronically automatically evaluated with an image evaluating device for determining the presence of foreign bodies. After recognizing a foreign body such as a thread or an accumulation of threads, a removal apparatus at an accurately calculated distance from the locus of determination is activated which removes the material zone of the loose layer where the foreign body was found.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic side elevational view, with block diagram, showing a preferred embodiment of the invention.
FIG. 2 is a schematic side elevational view, partially in section, of components of a further preferred embodiment of the invention.
FIG. 3 is a schematic side elevational view, partially in section, of components of still another preferred embodiment of the invention.
FIG. 4 is a schematic side elevational view with a block diagram, showing another preferred embodiment of the invention.
FIG. 5 is a schematic side elevational view of a further preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, there is illustrated a travelling bale opener 1 which includes opening rollers 3a, 3b for removing, during the travel of the bale opener, fiber tufts from the top faces of serially arranged fiber bales 2. The bale opener may be a "BLENDOMAT BDT" model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Federal Republic of Germany. The fiber tufts are pneumatically conveyed through a channel 4 and a conveyor duct 5 to a condenser 6, downstream of which there is arranged a stripping roller 7. The condenser 6 is situated at the upper end of a fiber tuft fill chute 8 (fiber tuft feeding device) which includes two delivery rollers 9a, 9b.
Underneath the fill chute 8 there is situated a conveyor belt 10 which is constituted by a sieve belt. Between the upper reach 10a and the lower reach 10b of the conveyor belt 10 there is situated a suction device 11 by means of which the upper reach 10a is exposed to suction from below. The suction device 11 comprises a shroud assembly 11a and a blower 12 connected at its suction side to the shroud assembly 11a. The loose fiber tuft mass 13 (layer) on the upper belt reach 10a has a relatively small thickness. Downstream of the conveyor belt 10 there is arranged a further conveyor belt 14. Between the two conveyor belts 10 and 14 a clearance 14a is present, underneath which a waste collector 15 is provided. At that end of the conveyor belt 14 which is remote from the conveyor belt 10 there is situated a suction device 16 for removing the fiber tufts.
Above the upper reach 10a of the conveyor belt 10 there is arranged a picture taking device, such as a television camera 17 oriented towards the fiber tuft mass 13. The camera 17 applies signals to an image storing device 18, an image evaluating device 19 for distinguishing foreign bodies from fiber tufts and a switching device 20 which, in turn, is connected with the drive motor 21 for the conveyor belt 14.
In operation, the tuft fill chute 8 scatters the fiber material as fiber tufts in a downward direction over a width of approximately 1 meter. Underneath this fiber tuft delivering station there is situated the conveyor belt (sieve belt) 10 which is exposed to a vacuum by the suction device 11. The conveyor belt 10 is driven by means of rollers 10c and 10d in a direction indicated by the arrow D. The speed of the non-illustrated motor for driving the conveyor belt 10 (for example, by virtue of rotating the roller 10c) is variable. By means of this apparatus, there is obtained a relatively uniform fiber tuft mass 13 whose density (thickness) may be adjusted in a desired manner by altering the travelling speed of the conveyor belt 10. The suction effect of the blower 12 provides that the fiber tufts of the fiber tuft mass 13 are compressed and thus the upper face of the fiber tuft layer is reduced and further, during the travel of the conveyor belt 10 there will be no appreciable relative velocities between the upper reach (conveying surface) 10a of the conveyor belt 10 and the fiber tufts of the fiber tuft layer 13.
The camera 17 monitors from above an approximately square zone and takes pictures which are stored in the memory 18. The sequence of picture taking by the camera corresponds to the belt speed such that each time a new layer portion arrives in the entire range of the camera 17 the subsequent picture will be taken thereby. The image evaluating device 19 detects any foreign body, such as foreign fibers. Downstream of the conveyor belt 10 there is arranged the additional conveyor belt 14 whose drive 21 is connected to the switching device 20, which at a predetermined moment after a foreign body was detected by the evaluating device 19, causes reversal of the conveyor belt 14 into the direction E. In this manner, the fiber mass 13, containing the foreign bodies 39 may be deflected downwardly into the waste container 15.
Turning now to FIG. 2, downstream of the conveyor belt 10 there is arranged a suction device 16' which is, in turn, connected with a conveyor duct 23 with the intermediary of a fiber tuft driving fan 22. With the conveyor duct 23 there is connected a tubular switch (deflector tube) 24 which is connected with the electric switching device 20, arranged as shown in FIG. 1. When the evaluating device 19 determines the presence of a foreign body 39 in the fiber material 13, the switching device 20 emits a signal which is applied to the non-illustrated driving device for the tubular switch 24 which, in response, pivots in the direction of the arrow A into the position 24a shown in phantom lines. In this manner, the fiber material, containing the foreign bodies 39 is caused to follow a detour. Subsequently, the tubular switch 24 is pivoted back into its normal, solid-line position in the direction of the arrow B to ensure that the fiber material now free from foreign bodies may follow its normal path to further processing.
Turning now to FIG. 3, above the downstream end of the upper reach 10a of the conveyor belt 10 there is provided a suction device 26 which, by means of the blower 28, lifts the fiber tufts off the conveyor belt 10 through the suction nozzle 26a and normally drives the fiber material into the duct 26b for further processing. For this operation a pivotal gate 29 is in its closed position shown in phantom lines at 29a. When the device 19 detects a foreign body 39 in the fiber material 13, the switching device 20 applies a signal to the actuating means 30 which pivots the gate 29 downwardly as indicated by the double-headed arrow C into its open position whereby the fiber material is taken out of the conduit 27 and introduced into a waste duct 16".
Turning now to the embodiment illustrated in FIG. 4, downstream of the discharge (delivering) rollers 9a and 9b there is arranged an opening roller 9c which directs the fiber tufts onto the upper reach 10a of the belt 10. Above the upper reach 10a there is situated a transmitting device 31 for emitting electromagnetic waves or rays, such as an X-ray apparatus. Between the upper reach 10a and the lower reach 10b of the conveyor belt 10 there is situated a receiver 32. The material of the conveyor belt 10 is pervious to electromagnetic irradiation. In this embodiment the loose fiber tuft layer 13 is traversed by irradiation. To the receiver 32 there are connected an image storing device 18, an image evaluating device 19, a signal transmitter 34 and a switching device 20, the latter being operatively coupled with a device for removing portions of the fiber tuft material containing the detected foreign body, as described in connection with the mechanisms shown in FIGS. 1, 2 and 3.
Turning to the embodiment illustrated in FIG. 5, there is shown a camera 17 arranged above the conveyor belt 10. With the end roller 10d supporting the conveyor belt 10 there cooperates a reversing device 35 for the fiber tuft layer 13, formed of an endless belt 36 supported by rollers 37a-37d driven in a direction opposite to the direction of rotation of the rollers 10c and 10d supporting the conveyor belt 10. At the downstream end of the conveyor belt 10 the fiber material 13 is grasped by the upper face 36a of the belt 36 as it cooperates with that portion of the conveyor belt 10 which is momentarily supported by the end roller 10d. Between a deflecting roller 38 and an end roller 37d the belt 36 has a horizontal belt portion 36a above which there is situated a further camera 17'. By virtue of the reversing device 35, at the downstream end of the upper reach 10a of the belt conveyor 10 the advanced fiber layer 13 is turned upside down to permit, by the camera 17', an observation of that side of the layer 13 which was the bottom side on the conveyor 10. The camera 17' may be connected to the devices 18, 19 and 20, similarly to the camera 17 associated with the conveyor belt 10.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | An arrangement for ascertaining the presence of foreign bodies in a mass of fiber tufts comprises a fiber tuft-supporting surface; a device for providing a loose fiber tuft layer on the tuft-supporting surface; a foreign body detecting apparatus arranged for scanning the fiber tuft layer for foreign bodies; and a moving device for effecting relative displacement between the fiber tuft layer and the apparatus. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the art of automatic machine tools and particularly to spindle tracing shapers with logic systems which sequentially control the operation of the machine from start to finish.
2. Description of the Prior Art
Spindle shapers performing woodworking operations under the control of a fixture or template have heretofore required manual operations which are hazardous to perform and require the services of highly skilled operators. These machines have required fences, collars and the like to guide the workpiece against the shaper tool and although various pull-down devices, safety rings and the like have been provided, the operation requires positioning of the operator's hands close to the tool and considerable skill is needed in manipulating the workpiece relative to the guides.
It would, therefore, be an improvement in the art to provide a spindle tracing shaper with automatic controls which sequence the cutting operation from start to finish without exposing the operator to the shaper tool and without requiring skilled services of the operator.
SUMMARY OF THE INVENTION
According to this invention, a spindle tracing shaper is provided with a laterally extending track secured to the plate or table top of the machine from which the upright spindle projects. The track slidably supports a vacuum feed table or chuck which clamps a template or pattern and workpiece thereon under the influence of vacuum. The operator initially positions the chuck on the track to accommodate the selected pattern and workpiece to be shaped. Workpieces throughout a wide size range are thus easily accommodated. Then the operator secures the chuck to an automatic biasing device which draws the pattern against a rotatable bearing or stop on the spindle under a controlled constant load. The biasing means is preferably an air cylinder with a piston rod extension being selectively secured along the length thereof to the chuck for the initial positioning. A variable speed drive rotates the chuck to advance the workpiece against the shaper tool at a desired feed rate. The rotation continues beyond a full cutting cycle, preferably 440° rotation, then automatically stops, whereupon the biasing means retracts the chuck to its initial position. The vacuum is then shut off manually to permit manual removal of the finished workpiece.
A hood over the table top of the spindle shaper is connected to the suction side of a blower creating an air stream drawing off the wood chips. Opposing holddown wheels, one fixed but removable and one movable to raised and lowered positions, secure the workpiece against axial vibration near the shaper spindle.
A brush suspended from the hood surrounds the shaper tool and spindle to trap the wood chips and further to protect the operator.
An air logic system controls the sequential operation of the vacuum loading, the biasing loading and the loading of the hold-down wheel. With relays regulating starting and stopping the table, and a vacuum system for the chuck providing a minimum of 20 inches of mercury vacuum pressure at the table, the table drive by an SCR (silicon control rectifier) drive, can vary table rotation from 0.33 to 14 R.P.M. The cycling system is interlocked preventing start until the vacuum pressure is at least 20 inches of mercury. Workpieces of from 9 inches to 72 inches are easily accommodated. The shaper blade tools are easily applied and removed and can be of the climb or conventional cut type.
The table top is mounted on a cabinet base at a convenient working height and the cabinet houses the spindle drive, mechanism for raising and lowering the spindle, vacuum pump, the sensors and other controls. The hood has a control panel on one face thereof.
Further objects and features of this invention will be understood from the following:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an automatic tracing shaper of this invention.
FIG. 2 is a side elevational view of the shaper of FIG. 1.
FIG. 3 is a sectional view with parts in plan, along the line III--III of FIG. 2.
FIG. 4 is a sectional view, with parts in elevation, along the line IV--IV of FIG. 3.
FIG. 4A is a partial view of FIG. 4 but with the carriage in retracted position and showing a bottom clamp wheel bolted in position under the workpiece.
FIG. 5 is a longitudinal sectional view of the vacuum chuck and drive mechanism along the line V--V of FIG. 3.
FIG. 6 is a view of the control panel.
FIG. 7 is a cycle flow diagram of the pneumatic logic controls.
FIG. 8 is an electric circuit diagram for the motors.
FIG. 9 is a cycle diagram of operation of the shaper.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The fully automated tracing spindle shaper 10 of this invention, as shown in FIGS. 1 and 2 has a generally rectangular cabinet base 11 with a table top 12 and an exhaust hood 13 overlying this. A box-like collar 14 on the table top 12 surrounds a central open front and open top work zone of the table top 12. The top of the collar 14 is flat and at a convenient height for the machine operator. The flat top of the collar 14 assists in the support of the workpiece. The front side of the cabinet base 11 has a track or slide support 15 projecting laterally from the open front portion of the table top or plate 12. This track 15 includes a pair of spaced parallel horizontal rods 16 with inner ends clamped by brackets 17 to the table top 12, as shown in FIG. 3. The outer ends of the rods 16 are secured in vertical brace connected plates or frames 18 supported by inclined rods 19 from the bottom of the cabinet base 11. The track 15 is thus rigidly supported from the machine base or frame 11 to hold the guide rail rods or tracks 16 in fixed spaced parallel horizontal relation.
A feed table or chuck carriage 20 is slidably supported on the rail rods 16 through anti-friction bearing equipped bosses 20a as shown in FIG. 3. This carriage therefore has a range of lateral movement projecting over the table top 12 all the way outwardly therefrom to the plates 18.
The vertical spindle 21 of the machine projects into the central area surrounded by the collar 14 and, as shown in FIG. 4, is rotatably supported at its lower end in the cabinet 11 by a vertically adjustable slide 22 supported on an upright base 23 depending from the top plate 12. The slide 22 is raised and lowered by rotation of a hand wheel 24 projecting from the front wall of the cabinet base 11 and rotating a worm 25 meshed with a gear 26 on an upright screw rod 27 threaded in a flange 28 of the slide 22.
The slide 22 also supports a 3600 RPM electric motor 29 with a multiple pulley and belt drive connection 30 to the spindle 21. The superimposed drive and driven pulleys of this drive connection have different diameters so that the belt may be exchanged therebetween to vary the range of speed from the motor 29.
The upper end of the spindle 21 is keyed to an easily applied and removed shaper head or tool 31. A nut 32 secures the head 31 in fixed position on the spindle.
An anti-friction bearing or collar 33 surrounds the spindle below the cutter head 31 and has a freely rotating outer race engaged by an underlying spring pressed friction pad 34 carried from a bracket 35 on the table top behind the spindle to hold the outer race of the bearing collar 33 against free rotation with the spindle.
The carriage 20 rotatably supports the feed table or chuck 36 as shown in FIG. 5. This table 36 has a central hollow stem 37 carried in anti-friction bearings 38b from the carriage 20 and the stem receives freely therethrough a non-rotatable vacuum tube 38 opening to the center of a recess 39 in the top face of the chuck 36 which is surrounded by a flexible seal or gasket 40. The bottom of the tube 38 has a head 38a below the stem 37 receiving a forwardly projecting vacuum tube or pipe 41 which, as shown in FIG. 2, is connected at its forward end to a depending expansible and contractible coiled tube 42, the lower end of which is connected through a tube 43 to the suction side of a vacuum pump 44 mounted in the bottom of the cabinet base 11.
Additional bearings are provided to stabilize rotation of the chuck 36 on the carriage 20, and as shown in FIG. 5, vertical needle bearings 45 surround the stem 37 above the main bearings 38b while horizontal needle bearings 46 underlie the bottom face of the chuck 36.
The chuck 36 is driven by a motor 47 suspended from the carriage 20 and having a horizontal drive sprocket 48 driving an endless chain 49 meshed around a larger sprocket 50 secured to the bottom of the chuck 36. The motor 47 is preferably of the direct current type delivering high torque to rotate the chuck through a broad feed range of, say, from 0.33 to 14 R.P.M.
A cover 51 overlies the sprocket 48 and the portion of the chain 49 beyond the chuck 36 being removably secured to the carriage 20 by fasteners such as 52, as shown in FIG. 5.
As shown in FIG. 3, a pneumatic jack with an air cylinder 53 is horizontally mounted on the plate 12 in the box-like collar 14 and has a piston 54 with a piston rod 55 projecting from the front end of the cylinder and secured to an external elongated rod 56 with an outer end slidable through a frame plate 18, and with an intermediate portion slidable through a screw clamp 57 projecting from a bearing 20a of the carriage 20. As the piston 54 is propelled in the cylinder 53, the elongated rod 56 will be driven to slide through a frame 18 and the clamp 57. However, when the clamp 57 is tightened, the carriage 20 will be driven by this piston 54. The carriage 20 is initially positioned on the track 15 to accommodate a workpiece of the selected size with its periphery closely adjacent the shaper tool 31, whereupon the clamp 57 is tightened and actuation of the air cylinder will bias the workpiece toward the shaper tool.
As shown in FIGS. 4 and 5, a centrally apertured template or pattern 58 is mounted on the chuck 36 resting on the gasket or seal ring 40 and having its central hole or aperture 58a aligned with the vacuum tube 38. A workpiece W.P. overlies this template 58 covering the aperture 58a. A sealing gasket 40a is also preferably interposed between the bottom of the workpiece and the top of the template. Suction applied through the tube 38 will thereby draw the workpiece W.P. tightly against the template 58 or interposed gasket 40a and the template in turn will be drawn tightly against the sealing gasket 40, whereupon the workpiece and its tracing pattern or template are securely clamped to the feed table or chuck 36.
The periphery of the template 58 is aligned with the collar or stop 33 and is biased thereagainst by the air cylinder 53 under a controlled air load causing the chuck to reciprocate on the track carrying the periphery of the workpiece W.P. against the shaper tool 31 under the influence of the template or pattern.
The table with its clamped on template and workpiece assembly is rotated by the motor 47 to advance the workpiece against the cutter head at a desired feed rate.
As shown in FIG. 3, a sensor 59 on the carriage 20 is tripped by a finger illustrated at 60 on the chain in FIG. 5 to stop the rotation of the chuck upon completion of the cutting cycle.
The hood 13 is supported on an upright frame 61 at the rear end of the table top 12 and has a central bonnet 62 overlying the shaper head 31 exhausting to a duct 63 which, as shown diagrammatically in FIG. 1, is connected to the inlet side 64 of an exhaust fan or blower 65 so that chips from the cutter head will be drawn through the bonnet 62 and exhausted through the duct 63. As shown in FIG. 2, a fringe curtain or brush 66 depends from the central bonnet 62 around the shaper tool 65 to direct the chips into the bonnet.
A pneumatic jack with an upright air cylinder 67 is mounted on the mounting plate 12 behind the support frame 61 in a closed compartment 68 with its piston rod 69 pinned at its upper end to a bracket 70 extending from the rear end of a parallelogram linkage 71 pivoted to the frame 61 at 72. This parallelogram linkage 71 supports, at its front end, a bracket 73 from which depends a roller 74 adapted to ride on the workpiece W.P. as shown in FIG. 4. The bracket 70 is also secured to the upper end of a coil spring 75 anchored through an adjustable screw 76 to the table top 12. When the air cylinder 67 is actuated to raise the piston rod 69, the parallelogram linkage will be tilted to press the roller 74 against the workpiece, but when the air is released from the cylinder 67, the spring 75 will raise the roller 74 off of the workpiece. This provides a hold-down claw riding on the workpiece near the cutter 31 to prevent vibration of the workpiece during the cutting action.
The air cylinder 67 may be automatically sensed from an proximity sensor 77 having an air nozzle discharging on top of the workpiece which offers a resistance to the discharge. The air cylinder, of course, can be supplied with air at selected pressures to control the hold-down force of the roller 74.
As shown in FIG. 4A, when a large workpiece W.P. and template 58 extend beyond the periphery of the chuck or table 36, the chuck is, of course, retracted from the FIG. 4 position and a caster wheel carrying plate 78 is bolted on the top 12 under the roller 74. The plate 78 has an upstanding internally threaded boss 79 into which is threaded the stem 80 of a caster wheel or roller 81. The height of the roller is adjusted to ride on the under face of the template or, if the workpiece projects beyond the template, on the under side of the workpiece, to cooperate with the roller 74 for holding the workpiece in a flat plane and dampening vibration.
A control panel 82 on a side of the hood 13 has switches and indicators to set up the shaper for automatic operation.
The control panel of FIG. 6 contains switches in the form of buttons, and rotating handles, visual indicators, and dials. The legends on the panel designate generally the function of each switch or indicator. Starting from the right-hand end of the panel, in the top row, is a push button start switch 100, a rotating or turn vacuum switch 101, a vacuum indicator light 102, a starting cycle push button switch 103, a retracting push button switch 104, a rotating turn switch 105, and a vacuum pressure dial 106. In the bottom row, from right to left, is a push button emergency stop switch 107, a rotating feed switch 108 with three positions "B" (brake), "R" (reverse) and "F" (forward). Below this feed switch is a rotating rheostat switch 109 for controlling the feed rate. Symbols from 0 through 10 designate various speeds controlled by this switch. To the left of the feed rate switch is a rotating turn switch 110 having a central "off" position, an "on" position to the left, and an "automatic" position to the right. The next switch 111 is of the rotating or turn type and has a manual position and an automatic position. The following switch 112 also of the turn type is a clamp switch with an off and on position. A rotating dial type switch 113 adjusts the pressure of the air cylinder 53 controlling the sliding of the chuck carriage on its track. The dial 114 indicates the air pressure in this cylinder 53.
The cycle flow diagram of FIG. 7 illustrates the switches and indicators of FIG. 6 and the shaper components controlled thereby from a shop source of compressed air. The air supply input is indicated at "A.S.". The switches in this diagram and the mechanisms or components controlled thereby have been marked with the same reference numerals used in FIG. 6, and in the above description of the mechanisms. As shown in this diagram, the "vacuum" switch 101 controls the air supply through two pneumatic circuits with an "on" position supplying vacuum to the chuck and an "off" position releasing the vacuum to permit removal of the workpiece from the chuck. The air supplied to the machine, however, continues through both positions of the switch 101.
FIG. 8 is an electrical diagram illustrating electrical power input to the three electric motors of the machine. As shown, the spindle motor 29 and the motor for the vacuum pump 44 are energized through a three-phase high voltage supply "S" with a step down transformer "T" reducing the voltage to a circuit controlling the DC motor 47 through the rectifier. The switches in this circuit also control the motor drive.
In the diagram of FIG. 9, the switches and indicators of FIG. 6 are shown in circuit relation with the devices which they control. The same reference numerals have been used for these devices and switches.
The following table is an operational description of the controls and sequence of operation of the pneumatic, electrical, and vacuum actuated units of the shaper machine. In this table, column 1 shows the symbols of the switches corresponding with the panel showing of FIG. 6, column 2 identifies the switches by the same numbers used in FIGS. 6 through 9, column 3 lists the various conditions of air, electrical and vacuum input to the machine, while column 4 shows the function of the switches.
__________________________________________________________________________SWITCH SWITCHSYMBOL NUMBER CONDITION FUNCTION__________________________________________________________________________Start 100 Power to Starts spindle motor 29 Machine Vacuum pump 44 Closes circuit to DC drive switches for motor 47.Vacuum 101 Air to Open valve to supply vacuumON/OFF Machine to table 36 Vacuum "OFF" Releases (W.P.) Pump On workpiece "ON" holds workpiece in placeVacuum 102 Vacuum "ON" Shows operator when thereIndicator with work- is adequate vacuum to hold piece making part in place and let good seal cycle startStart Cycle 103 Vacuum indi- Starts cycle as follows: cator "ON" 1. Retracts slide cylinder Rotary table moving slide towards clear of cutter. limit 59"Feed" 113 2. Starts DC drive motorswitch 47"Auto" 112 3. Allows proximity"Clamp" sensor 77 to closeswitch clamp 74"On" 4. Rotates table through approximately 440° Rotary table 5. Stops table rotation limit 59 contact 6. Extends slide cylinder 53, moving slide 20, away from spindle 7. Opens clamp 74 if closedRetract 104 Machine in Stops cycle, accomplishes operation in steps 5,6,7 above before mid-cycle table limit 59 contact is madeSlide 105 Operation "In" retracts cylinder 58,"In" Switch 111 slide 20 moves in "Out""Out" to Manual extends cylinder 63 slide 20 moves outVacuum 106 "Vacuum" Shows vacuum pressPress "ON" 101 maintained in system vacuum pump running, seal made at tableSlide 114 Air to Monitor air pressure onPress Machine slide cylinder 53Slide 113 Air to Adjust press to slidePress Machine cylinder 53AdjustClamp 112 Operation Activates and deactivates"ON" Switch clamp 74 (not used for"OFF" "AUTO" smaller workpieces)Operation 111 Activates the slide "IN"Man Auto "OUT" allowing the machine to be run manuallyFeed 113 Machine ON Operates DC drive 47 thatON/OFF/ Start 100 operates table rotationAUTO activates "ON", closes circuit to DC drive rotating table 20 "OFF", Opens circuit to DC drive 47 "AUTO", closes circuit to pressure switch which allows the DC drive 47 to rotate the table 36 automaticallyFeed 108 Reverses Rotary Table 36"R" "B" "R" Reverse, reverses"F" rotary table "B" Brake, stops rotary table "F" Forward, table rotates in opposite direction of reverseFeed Rate 109 Controls the speed the rotary table 36 rotates feeding the work through the cutter 31Emergency 107 Machine Stops all machine opera-Stop Running tions 1. Stops spindle motor, vacuum pump, and table rotation Machine in 2. Extends slide cylinder Operation 53 Mid-cycle 3. Opens clamp 74 if closed__________________________________________________________________________
It should be understood that while the air supply is illustrated in the diagram of FIG. 7 as a conventional machine shop compressed air source, the machine could be equipped with an air compressor energized, for example, from a separate electrical motor which would be energized through a circuit controlled by the switch 101.
From the above description, it will be understood that compressed air, vacuum, and electrical inputs are used to operate the components of the machine and pneumatic and electric circuits are provided with valves and switches to sequence the operation of the components as determined from a control panel on the machine. Conventional symbols for switches and valves have been used in the diagrams in FIGS. 7-9.
The above described machine of this invention is operated as follows:
OPERATION
With the carriage 20 in a retracted position away from the cutter head 31 and the clamp 57 in its released position, a template is centered on the chuck 36 covering the gasket or seal 40 and a workpiece W.P. is superimposed over the template thus covering the template aperture 58a. The carriage 20 is then advanced on the track 15 to position the template closely adjacent the bearing or collar 33 whereupon the clamp 57 is tightened, securing the chuck carriage 20 to the rod 56 of the air cylinder 53.
The start button 100 on the control panel 78 is then manually actuated to initiate rotation of the spindle drive motor 29 and the vacuum pump 44.
The on/off switch 101 on the control panel 78 is manually turned to the "ON" position supplying a vacuum load to the chuck 36 sufficient to securely clamp to workpiece and the template to the chuck 36. The sensor 77 in the air logic circuit checks for adequate vacuum pressure giving an indication on control panel 78 at 102. The cycle start button 103 is then manually activated causing the slide 20 to be pulled inward by the cylinder rod 55 pressing the template against the bearing stop 33, and actuating the chuck motor 47 for feeding the workpiece at a selected rate against the shaper tool or cutter head 31. Air is also admitted under the piston in the cylinder 67 through a supply line also vented through the sensor 77. If the air issuing from the sensor is blocked by the workpiece, the air pressure under the piston will raise the piston rod 69 tilting the linkage 71 and pressing the roller 74 on the workpiece.
The motor 47 rotates the chuck through a complete cycle, whereupon the sensor 59 is tripped to deenergize the motor, stopping the chuck 36, raising the wheel 74 off of the workpiece and extending cylinder 53, thereby retracting the carriage 20 back to its starting position. The vacuum on/off switch 101 is manually turned to the "OFF" position releasing the workpiece (W.P.). The chuck having been rotated about 440° is already in a position to receive the next workpiece.
It will be especially noted that the entire cycle of operation from start to finish after the operator has placed the workpiece on the chuck is fully automated, and the operator's hands are never near the cutter head 31.
It will be apparent to those skilled in the art that many modifications and variations may be effected without departing from the spirit and scope of the novel concepts of the present invention. | A highly productive completely automatic tracing shaper machine tool performs sequential operations without manual attention permitting a single operator to simultaneously run several machines without being exposed to the shaper heads of the machine. The tracing shaper machine tool has a track mounted vacuum feed table or chuck clamping thereon a template or pattern and the wood workpiece to be shaped. The table is manually positioned on the track to accommodate a wide range of workpiece sizes and this initially positioned table or chuck with the stacked template and workpiece vacuum clamped thereon is automatically biased toward a selectable speed driven upright shaper tool carrying spindle with a rotatable follower bearing surrounding the spindle receiving the periphery of the template thereagainst at a constant pressure. The feed table or chuck is rotated to provide a desired feed rate of the workpiece to the shaper tool, and this rotation continues somewhat beyond a 360° turn, whereupon the biasing means is reversed and the chuck retracted to its starting position on the track. A hold-down wheel is automatically pressed against the workpiece adjacent the peripheral edge being cut by the shaper tool to prevent jumping of the workpiece from the cutting action. The machine has an air logic system sequentially controlling the operating steps. | 1 |
CROSS-REFERENCE
[0001] This application claims the benefit of U.S. Provisional Application No. 61/535,753, filed Sep. 16, 2011; U.S. Provisional Application No. 61/585,580 filed on Jan. 11, 2012; and U.S. Provisional Application No. 61/615,141 filed on Mar. 23, 2012, all of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The invention relates generally to the diagnosis and treatment of disorders using minimally invasive techniques. In many minimally invasive procedures very small devices are manipulated within the patient's body under visualization from a live imaging source like ultrasound, fluoroscopy, or endoscopy. Live imaging in a minimally invasive procedure may be supplemented or replaced by displaying the position of a sensored medical device within a stored image of the patient anatomy.
[0003] Many minimally invasive catheter procedures are conducted in expensive hospital settings by specialized physicians. Often small, percutaneous medical devices are visualized during the procedure by using live fluoroscopic imaging. While the fluoroscopic imaging provides a live image of fluoro-opaque devices, it has many drawbacks:
[0004] Time spent in a fluoroscopy suite is very expensive and raises the cost of many minimally invasive medical procedures.
[0005] Ionizing radiation used to create the fluoroscopic image is dangerous to the patient, physician, and assistants.
[0006] The fluoroscopic image is a two-dimensional projection which does not provide determinant information about motion of the medical device towards or away from the fluoroscopic image collector
[0007] During a typical minimally invasive procedure the physician must look away from the patient and his or her hands to see the display showing the fluoroscopic image. Additionally, the frame of reference for the fluoroscopic image is typically misaligned from the frames of reference for the physician, the tool and the patient. This presents a challenging situation for the physician who must compensate for differences in these frames of reference. For instance, when the physician inserts a device into the patient by moving his hands from left to right, the fluoroscopic image of the device moves towards the top of the display. The physician must compensate for the misalignment of the coordinate systems for the respective frames of references while also concentrating on achieving the goals of the minimally invasive procedure. All the while the physician's need to look away from the patient and his or her instrument creates an ergonomic challenge in addition to this mental challenge. As a result the completion of minimally invasive procedures becomes delayed increasing the procedure cost and the exposure of the patient and surgical team to ionizing radiation.
[0008] Prior to a minimally invasive catheter procedure, patients often have an anatomical image created using CT or MR imaging systems commercially provided by companies like Philips, Siemens, General Electric, and Toshiba. The anatomical images can be processed, or “segmented,” into three-dimensional representations of the anatomy of interest. Individual organs, muscles and vasculature can be visually separated from other anatomy for even clearer viewing of regions of interest. In this invention the three-dimensional pre-procedure images may be used instead of fluoroscopy for navigation during the procedure because the position and orientation of the medical device can be sensed in real-time. For example, navigation systems provided by Medtronic, GE, and Stryker sense the positions of medical devices within the patient's body and present the sensed position data in a pre-procedural image of the patient's anatomy. These navigation systems provide a supplement or replacement to fluoroscopic imaging so that the physician may conduct a minimally invasive procedure within the patient's body using little or no X-ray. However, the navigation systems do not provide a means for making the physician's hand motions on the medical device match the motions of the device displayed in the image of the anatomy on the display. In order to make minimally invasive procedures easy and intuitive, the coordinate systems of the patient, the device, the display, and the physician's hands must be unified.
[0009] Minimally invasive procedures where the medical device follows the natural paths of internal anatomical conduits are especially well suited for a system that provides navigation assistance by unifying the physician, patient, display, and device coordinate systems. These procedures usually employ very small devices that are internally navigated through very small anatomical conduits. For example, to treat uterine fibroid tumors, a physician inserts a small 5 F (0.065″) catheter through the femoral artery into the internal iliac artery and then advances a 3 F (0.039″) catheter into the uterine artery. In this procedure, the arteries that provide a conduit for the medical devices are often only 1-2 mm (0.039-0.078″) in diameter and a small error in navigation may result in the physician being unable to reliably choose the correct pathway. Similarly, to treat drug-refractory hypertension, a physician may insert a 6 F ablation catheter through the femoral artery to the aorta and into the renal artery under live fluoroscopic imaging. If live X-ray were not needed, the renal ablation procedure could be done more quickly and less expensively.
[0010] The present invention minimizes the exposure of the patient to ionizing radiation and improves the ease and reliability of navigating a minimally invasive device within a patient by providing a system for displaying the device and patient anatomy in a substantially aligned manner.
SUMMARY OF THE INVENTION
[0011] The invention comprises a virtual window system that creates a visual coherency between the image of the patient and his or her anatomy and the patient by aligning the image of the patient anatomy on the display to the patient and presenting the image to the user that feels is if the user is looking directly into the patient through the display. The invention is designed to also display medical devices, such as a minimally invasive tool. The invention makes the anatomy and the motion of the minimally invasive medical device in the display match the motion of the physician's hands by substantially unifying the coordinate systems of the patient, the medical device, the display, and the physician's hands. The invention creates a visual coherency between the motion of the medical device in the image and the motion of the physician's hands manipulating the device. This invention also creates a visual coherency between the motion of the image in the display and display.
[0012] Embodiments of the invention possess inventive design elements that improve the ergonomics and increase the workspace of the virtual window surgical system. Furthermore, coupling the position and orientation of the display to the image allows the image to remain aligned to the patient for various positions and orientations of the display. To improve the workspace of the system, this invention allows for decoupling the relationship to reposition the display independently of the image. For instance, an aligned display may interfere with other equipment during some portion of the procedure and it may be desirable to un-align and reposition the display slightly to relieve the interference. Additionally this invention allows for a scaled coupling for improved ergonomics. For instance, moving the display with a unity ratio may cause the display to interfere with other equipment during some portion of the procedure or may make the screen difficult to view. A 1.5:1 scale would increase the ergonomics of the system while maintaining the visual coherency between the patient and the image. It should be noted that the display may be repositioned along multiple axes and in multiple directions and that the scaling may be different for different axes and directions. Additionally this invention provides a movable support structure to place a display directly in front of the physician, in between the physician and the patient. Ideally the images are presented in a fashion such that the images are substantially aligned with the patient. This invention details the methods and techniques needed to align the images to the patient. Many embodiments utilize a display that is mounted on a movable support structure that allows for the display to be positioned between the patient and the physician. The range of motion of the support structure and the degrees of freedom enable a wide range of display positions and orientations. In one embodiment, the patient is lying on a surgical table with the physician standing by the patient's side. The support structure allows the display to be brought over the patient. The physician can move and orient the display so the display is located roughly between him/her and the patient. This improves the ergonomics of the surgical workspace by allowing the physician's general gaze to remain in the same spot throughout the procedure, without having to look up to a display located away from the surgical site.
[0013] Furthermore, techniques are disclosed to track the position of the display, the imaging source, the patient, and the table. Tracking individual elements of the system allows the image to be aligned with the patient and constantly updated to accommodate for a moving patient, moving table, moving imaging source, or moving display.
[0014] Specific embodiments of the display support structure are also disclosed. The support structures described allow for maximum versatility and usability.
[0015] Unifying the position of the display image and the patient anatomy makes the physician's control of a medical device within the anatomical image substantially coordinated, ultimately resulting in faster, easier, and more precise medical procedures. Additionally, this invention provides for a switch to decouple the relationship between the display position and orientation and the image position and orientation. This allows the user to move the display to a new position without affecting the image. This may be desirable if the display itself is interfering with some portion of the procedure, like the imaging source itself, and a different position would be more desirable. This invention also allows for the relationship between the display position and orientation and the image position and orientation to be scaled. A scaled relationship of greater than one would cause the image to move more than the display. A 1.5:1 ratio is preferred to increase the ergonomics of the system while maintaining the perception of a virtual window.
[0016] In a second embodiment, a live image of the patient anatomy is displayed on a display located over the patient. Sensors track the position and orientation of the display screen and the imaging source so that the position and orientation of the display screen may control position and orientation of the imaging source, to keep the anatomical image, the medical device image, and the patient substantially co-aligned. Alternatively, sensors track the position and orientation of the display screen and the imaging source so that the position and orientation of the imaging source may control position and orientation of the display screen, to keep the anatomical image, the display screen, the medical device image, and the patient substantially co-aligned. The live image may be supplemented with other anatomical images from live or static sources that are sensored, registered, and displayed in the same substantially co-aligned manner on the display screen.
[0017] Each of these embodiments creates a coupling between the image position and orientation and the position and orientation of a secondary system component. This invention improves the workspace of the system by providing an input device to temporarily decouple the relationship to reposition the display or secondary system component for improved workspace. Additionally, this invention improves the ergonomics by allowing for a scaling factor between the coupled display and secondary system component.
[0018] In another embodiment the system comprises a processor further adapted to receive image data for the patient's anatomy. Such image data may be a static image obtained by MRI, ultrasound, X-ray, computed tomography or fluoroscopic imaging modalities. The image data can also be a live fluoroscopic image collected in real-time. The system can further track patient position by one or more of the following fiducials, live imaging data, external optical sensors, or electromagnetic sensors. The processor is also further adapted to receive position data from a tool, which is tracked by electromagnetic sensors. The display is held by a support arm having at least 1 degree of freedom, wherein the members and joints of the support arm may be operatively coupled to counterbalance springs or weights. The processor is further adapted to receive position data of the display, which is tracked by one or more of the following: external optical tracking, electromagnetic sensors, or encoded joints of the support arm. The processor processes the various position data and image data to display an image of the patient's anatomy substantially aligned with the patient's actual anatomy superimposed with the position of any tool being tracked. The processor is also adapted to direct any live imaging equipment to ensure proper functioning of the system. When used in a surgical setting the invention may be located in the surgical field and may also comprise a sterile drape for the display to protect the integrity of the surgical field.
[0019] In one embodiment, a live image of the patient anatomy is shown on a repositionable display screen located over the patient. The physician can move the display over the patient while sensors track the motion of the display so that the image shown on the display screen may be periodically or constantly updated to show the medical device, and the patient anatomy substantially aligned with the patient from the perspective of the user. In this manner, the image shown on the display provides a view of the medical device and patient anatomy that is intuitive and allows for easy navigation of the medical device within the patient anatomy shown on the display screen. While the image of the anatomy is frequently based on a pre-operative image, a live image may be supplemented with other anatomical images from live or static sources which are sensored, registered, and displayed in the same substantially co-aligned manner on the display screen.
[0020] In additional embodiments, a sensor on the medical device provides position and orientation data of the device to a data processor. A sensor on the patient provides position and orientation data of the patient to the processor, and sensors on the display screen provide the viewing position and orientation of the display screen to the processor. With data from the medical device, the patient, and the display, the processor unifies the three coordinate systems so that the image shown on the display screen substantially matches the position of the patient anatomy. Adjustments to the display position over the patient result in similar changes to the position of the image in the display: changing the position of the display changes the view of the image on the display screen. For example, the user may change the angle of the display to change the angle of the apparent image on the display screen or may translate the display to pan the image in the display along the patient to show different anatomy. Aligning the positions of the shown image and the patient anatomy helps coordinate the physician's control of the medical device.
[0021] Elements of both embodiments may be combined to display preoperative and intra-operative anatomical images within the same procedure. In both embodiments, the invention provides a virtual window into the patient where the physician may view the anatomy and navigate the surgical device in substantial alignment with the patient.
[0022] In a first aspect of the present invention, a system for displaying an image for the tool on an image of a patient on a moveable display comprises a display screen and a processor. The display screen is configures to be moved and aligned with the target region on an exterior of a patient's body, and the processor is configured to receive data representing the patient's, data representing a position of a tool introduced to the patient's body in real time, and data representing a position of the display screen in real time. The processor is configured to deliver to the display an image of the patient anatomy having an image of the tool superimposed thereon. A position of the image of the tool on the image of the anatomy is updated in real time, and a target region of the anatomy which is presented as a virtual image on the display is selected by moving the display screen relative to the region and the patient body. The system can be used in performing methods for displaying the image of the tool on the patient image as described in more detail below.
[0023] In specific embodiments of the systems of the present invention, the system further comprises an external tracker for tracking a position of the tool in the patient's body, where the tracker generates the data delivered to the processor. For example, the tracker can be configured to track an electromagnetic sensor on the tool, as described in more detail below.
[0024] In further specific aspects of the systems of the present invention, the system may comprise a support for moveably holding the display screen relative to the patient's body. The support may, for example, may comprise an articulated arm, and the support may optionally be encoded to produce the data representing the position of the display screen which is sent to the processor.
[0025] In further specific embodiments, the system may further comprise an external tracker for tracking the screen to produce data representing a position of the display screen. The external tracker may be configured to track an electromagnetic sensor on the screen, and in many embodiments may be the same external tracker which is used for tracking the position of the tool and optionally for tracking the position of the patient body as described in more detail below. External trackers used in the present invention may also rely on other tracking technologies, including acoustic signals, optical sensors, encoders, fiducial markers, patient patches, and the like.
[0026] The patient anatomy data may be derived from a variety of conventional patient imaging methodologies, including x-rays, fluoroscopy, CT scanning, MRI, ultrasound, and the like. The images are converted to a data stream which is delivered to the processor, and the images may be static or delivered in real time. By “static image,” is meant that in pre-operative images obtain of the target regions in the patient body and the image used then to allow the processor to display selected target regions from the larger anatomy which has been imaged. Real time images will be obtained using an imaging device which is located adjacent the patient and which is typically repositioned to align the image with the target anatomy. This will be discussed in greater detail below. Movement and positioning of the imaging device may be controlled through the imaging screen.
[0027] In further specific embodiments of the systems of the present invention, an external track is configured to track movement of the patient's body, where the processor is further configured to receive data from the tracker representing the position of the patient's body. The processor adjusts the position of the patient anatomy which is presented on the display screen in response to the body movements in real time, thus assuring that the images of the patient anatomy and the tool remain properly registered with the patient's body over time. As noted above, this external tracker may be in addition to one or more other external trackers or may be combined in a single external tracker for tracking the display screen and the tool.
[0028] In a second aspect of the present invention, the methods for displaying an image of a tool on an image of a patient on a moveable display screen comprise aligning the display screen with a region of the patient's body approximate a target anatomy of the patient. An image of the target anatomy is displayed on the display screen, and an image of a tool is superimposed on the image of the target anatomy. The position of the tool image corresponds to a position of an actual tool in or on the actual patient anatomy. The position of the tool image on the anatomy image is updated in real time as the position of the actual tool changes relative to the actual patient anatomy. A region of the anatomy which is presented on the display screen can be changed by moving the display screen relative to the region of the anatomy and the patient. In this way, the user can track the position of the actual tool in real time on an image of the patient anatomy as the tool is being advanced, deployed, or otherwise positioned or repositioned within the actual patient anatomy.
[0029] Displaying the image of the target anatomy may comprise either displaying a pre-operative static image, displaying a real-time image obtained by an imaging device, or some combination of the two. Position data of the tool in real time is typically obtained by tracking the tool in the actual patient anatomy using an external tracker, such as those described above. A position of the display screen is also tracked, typically using an external tracker as described above, and the changes in position are used to update the images to presented on the display screen. Additionally, a position of the patient's actual anatomy may be monitored and further used to shift the coordinates system upon which the anatomy and the tool images are presented in response to changes in patient and actual anatomy positions.
[0030] In a third aspect of the present invention, a system for displaying an image of a patient anatomy on a moveable display comprises a display screen, a processor, and means on the display screen allowing a user to adjust a spatial relationship between the position of the display screen and an image of patient anatomy represented on the display screen. The processor is typically configured to receive data representing the patient's anatomy and data representing a position of the display screen in real time. The processor is typically further configured to deliver to the display screen an image of the patient anatomy to which changes in real time in response to movement of the display screen in accordance with a spatial relationship between a position of the patient's actual anatomy and the position of the display screen in real time.
[0031] The display screen means optionally allows a user to selectively interrupt the spatial relationship so that the image of the patient's anatomy remains unchanged while the display screen is moved and to thereafter resume the spatial relationship (tracking) so that the image of the patient's anatomy can resume moving and being updated on the display screen.
[0032] Alternatively or additionally, the display screen means can allow a user to adjust the scale of the spatial relationship so that movement of the display screen through a particular distance results in a corresponding movement of the image on the anatomy over a different apparent distance. The apparent distance on the display screen may be greater than or less than that of the actual movement.
[0033] The display screen means more typically comprise a tracking feature on the display screen itself, but could in other instances be on the processor, be on a separate controller (such as a footswitch), or the like. When on the display screen, the tracking feature may comprise any one of a tracking pad, a roller ball, a joy stick, or the like. Alternatively, the tracking feature could be implemented on a touch screen which may be the display screen itself. As a still further alternative, the tracking feature could be voice-activated.
[0034] Other features of the system of the third aspect of the present invention have been described previously with respect to the first system above.
[0035] In a fourth aspect of the present invention, a method for displaying a patient image on a moveable display comprises aligning the display screen with a region of the patient's body approximate a target anatomy of the patient. An image of the target anatomy is displayed on the display screen where the image of the target anatomy has a spatial relationship between a position of the patient's actual anatomy and the position of the display screen in real time. As the display screen is moved relative to the actual anatomy, the spatial relationship may be adjusted in real time so that at least one of a scale of the spatial relationship or continuity of the spatial relationship is changed. The continuity may be changed by interrupting a spatial relationship so that the display screen can be moved without moving the image of the patient anatomy on the display screen. The relationship may be resumed later. The spatial relationship may be modified when interrupted such that upon resumption of the spatial relationship any changes in the position and orientation of the display made during the interrupted state are not used by the modified spatial relationship and do not affect the image delivered by the processor (using the spatial relationship) to the display. The movement of the image can then be resumed on the display screen has assumed a different spatial relationship (either in or out of alignment with the target region) with respect to the patient. Changing the scale of the spatial relationship adjusts the magnitude of movement of the image on the display screen relative to the magnitude of the actual distance that the display screen is moved relative to the patient. The scale can be selected so that the movements are on a 1:1 scale, or any other scale which is greater or less than a 1:1 scale.
[0036] Further aspects of the methods of the fourth aspect of the present invention have been described above with respect to the methods of the second aspect of the present invention.
[0037] In a fifth aspect of the present invention, systems for displaying an image from a repositionable patient imaging device on a moveable display comprise a display screen, a repositionable imaging device, and a processor. The display screen is configured to be moved and aligned with target regions on an exterior of a patient's body. The repositionable imaging device is configured to be moved and aligned with target regions on an exterior of a patient's body. The processor sis configured to coordinate movement of the display screen and of the repositionable imaging device so that the display screen is positioned in a desired relationship with the target region which is being imaged by the repositionable imaging device.
[0038] In a specific embodiment of the system, the processor may be configured to reposition the imaging device in response to movement of the display screen. In an alternative embodiment, the processor may be configured to move the display screen in response to repositioning of the device.
[0039] Other specific aspects of the fifth aspect of the present invention have been described previously with respect to the earlier described systems.
[0040] In a sixth aspect of the present invention, methods for displaying an image from a repositionable patient imaging device on a moveable display screen comprise repositioning the imaging device and moving the display screen. As the imaging device is repositioned to image different target regions on a patient's body. The display screen is moved to position the screen in a desired relationship with the target region being imaged by the imaging device. Repositioning of the imaging device and moving the display screen are coupled so that (1) repositioning the imaging device causes the display screen to move to maintain the desire relationship or (2) moving the display screen causes the imaging device to reposition to maintain the desired relationship.
[0041] In specific aspects of this method, movement of the display screen and repositioning of the imaging device may be scaled or the scale can be 1:1 or may be other than 1:1. Typically, means are provided on the screen for adjusting such scaling, although means could be provided on the processor, or other places, or may be voice-activated in order to adjust such scaling.
[0042] In any aspect of the present invention as described previously the display screen, patient, support arm or any live imaging sources may be equipped with sensors to produce position data of the display screen, patient, support arm, or live imaging source.
[0043] Other features of the sixth aspect of the present invention has been described previously with earlier aspects.
INCORPORATION BY REFERENCE
[0044] All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
[0046] FIG. 1 is a side diagrammatic view of a system for displaying a substantially co-aligned anatomical image with a sensored medical device over a patient's anatomy.
[0047] FIG. 2 is a block diagram showing data flow for the system in FIG. 1 .
[0048] FIG. 3 is an isometric view of an embodiment of the display and support arm positioned next to the patient table.
[0049] FIG. 4 is a plan view of the display with a three-dimensional segmented anatomic image and an icon showing the position of the sensored medical device.
[0050] FIG. 5 is a diagram of a percutaneously delivered minimally invasive sensored medical device within an anatomical conduit.
[0051] FIG. 6 is two plan view diagrams of the sensored percutaneous medical device.
[0052] FIG. 7 is a side diagrammatic view of a system for displaying a substantially co-aligned anatomical image with a sensored medical device and a live fluoroscopic imaging source over a patient's anatomy.
[0053] FIG. 8 is a block diagram showing data flow for the system in FIG. 7 .
[0054] FIG. 9 is a flow chart describing the basic steps for a minimally invasive procedure using a sensored medical device and the system for displaying a co-aligned image.
[0055] FIG. 10 is a flow chart describing an algorithm for displaying the icon of the sensored medical device within the conduits of the anatomical image.
[0056] FIG. 11 is a stepwise diagram of the potential results of the flowchart of FIG. 10 .
[0057] FIG. 12 is a flow chart describing a Kalman Filter algorithm for predicting the position and reducing the error band of a sensored medical device.
[0058] FIG. 13 is a stepwise diagram of the potential results of the flowchart of FIG. 12 .
[0059] FIG. 14 is a side diagrammatic view of a system for displaying a substantially co-aligned live anatomical image over a patient's anatomy.
[0060] FIG. 15 is a block diagram showing data flow coordinating the image display and live imaging source for the system in FIG. 14 .
[0061] FIG. 16 is a flow chart describing the basic steps for a minimally invasive procedure using a live imaging source and the system for displaying a co-aligned image.
[0062] FIG. 17 is a side diagrammatic view of a system for displaying a substantially co-aligned anatomical image with a live fluoroscopic imaging source and a live ultrasound imaging source over a patient's anatomy.
[0063] FIG. 18 is a detailed isometric view of an embodiment of the patient reference sensor.
[0064] FIG. 19 shows a schematic of system architecture for displaying an image dependant on both the position of the display and the status of the input device.
[0065] FIG. 20 shows a flow chart for re-positioning the display independently of the image.
[0066] FIG. 21 shows a flow chart for re-positioning the image independently of the display.
[0067] FIG. 22 shows an example of the display translated from the fluoroscopic imaging system.
[0068] FIG. 23 shows a schematic of system architecture for displaying an image dependant on a scaled position of the display.
[0069] FIG. 24 is an isometric view of an embodiment of the display and support arm positioned on a moveable cart next to the patient table.
[0070] FIG. 25 is side view of the display support arm.
[0071] FIG. 26 is an isometric view of the display support arm with a user input.
[0072] FIG. 27 is an isometric view of a display support arm attached to the patient table.
[0073] FIG. 28 is a side view of the support arm shown in FIG. 27 .
[0074] FIG. 29 is an isometric view of a surgical system with multiple tracking systems.
[0075] FIG. 30 is an isometric view of a simple display support arm attached to the patient table.
[0076] FIG. 31 is an isometric view of an alternate embodiment of a display support arm attached to the patient table.
[0077] FIG. 32 is an isometric view of an alternate embodiment of a display support arm on a moveable cart.
[0078] FIG. 33 is an isometric view of the construction of a sensored medical device.
[0079] FIG. 34 is a detailed view of a low profile rotatable connector for a sensored medical device.
DETAILED DESCRIPTION OF THE INVENTION
[0080] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
[0081] FIGS. 1-2 describe an embodiment for navigating a minimally invasive medical device within the patient using an acquired three-dimensional anatomical image shown in a display 7 that is substantially aligned to the patient anatomy. A sterile cover may be used to separate the display from the sterile operating field and the sterile cover may incorporate a conductive film to provide a sterile touch interface for a capacitive touch screen display. The sterile display cover may be a flexible, clear drape made of plastic like polyethylene or polyurethane film, a rigid plate made of clear plastic like polycarbonate or acrylic, or a combination of both flexible and rigid plastics. The display is preferably a light-weight, flat LCD display provided by manufacturers like LG Display, Philips, and Innolux or a light-weight, flat OLED display provided by manufacturers like Samsung and Sony. A prime example of such a display would be the NEC TFT color LCD module which provides a usable viewing angle of 85° in all directions. In FIG. 1 , the position of the medical device within the patient 5 is provided by an electromagnetic coil sensor located on the distal elongated section of the medical device 1 . The position of the sensor is derived through an electromagnetic transmitter 2 similar to those transmitters supplied commercially by NDI and Ascension Technology Corporation. Alternatively, the position of the medical device may be derived from an optical fiber position sensor like that supplied by Luna Innovations. A similar patient reference sensor 3 is placed on the patient in a reliably stable position like the outcropping of the pelvic bone, sternum or clavicle. The reference sensor or sensors provide frequently updated data describing the position of the patient anatomy in the same coordinate system as the medical device sensor. The patch holding the patient sensor may be placed on the patient before the patient's anatomy of interest is imaged and the patch may contain known X-ray visible materials such as tungsten, platinum-iridium, platinum, barium sulfide or iodine and MR visible materials such as gadolinium or vitamin E. The patch is visible within the image of the anatomy and therefore the patient reference sensor 3 can be registered to the three dimensional anatomical image. Position data from the sensor in the medical device 1 and patient reference sensor 3 and display support arm 4 are sent to the system processor 6 . The local coordinate systems of the medical device sensor 1 and display 7 may undergo a coordinate system transformation in the system processor so that the positions of the device sensor, patient sensor, and display may be evaluated in a single world coordinate system. Display 7 has a user input button 8 .
[0082] FIG. 2 shows the flow of sensor position data from the sensor buffer 9 to the system processor 10 where the position sensor data is used by the processor to place an icon of the medical device into the three-dimensional patient anatomy image for display through the system display 11 . The system processor is a standard computing system like those supplied by Dell or Hewlett Packard running an operating system like Windows or Linux. Position data from the system display and support arm is likewise used by the system processor to orient the image on the screen so that the image, based on display position data from the display 7 and support arm 4 and patient position data from the patient reference sensor 3 , is substantially aligned with the patient anatomy. Display position data may also be used to modify the image in the display, for example zooming or clipping the image as the display moves closer to the patient. Other image modifications may include changing transparency, removing layers, removing anatomical structures, or changing colors. Additionally, scaling of the image in discrete steps or image modifications may be done via a touch sensitive surface on the display.
[0083] FIG. 3 presents an embodiment of the display and support arm with passively counterbalanced joints at the support arm elbow 13 , and shoulder 14 . An additional rotational or linear joint is provided at the base of the shoulder 15 to allow the display to move along the inferior to superior axis of the patient. All support arm joints may be encoded to provide data describing the position of the display. The display support is shown in an embodiment where the arm is mounted to a portable cart that is positioned next to the patient table. Axis 12 allows the display to rotate. An alternate embodiment may attach to the table or imaging system.
[0084] FIG. 4 shows a close-up image of an embodiment of the display with three-dimensional vascular anatomy 16 presented on the display. An icon, representing the location the position sensor of the catheter 17 is shown within the three-dimensional anatomical image along with a semi-transparent spherical icon 18 showing the accuracy of the positional data for the catheter position is displayed.
[0085] A preferred embodiment of the sensored medical device is shown in FIGS. 5-6 . The medical device is shown in a section of a blood vessel 19 with the distal articulating section 20 of the outer elongated tube, manually controlled by an internal pull-wire tensioning 24 lever on the handle 25 , curved to cannulate a branch of the vessel. The inner elongated tube 21 is extended to cannulate the distal branch of the vessel. A five degree-of-freedom single coil sensor 22 is wrapped and covered on the distal external section of the inner elongated tube. An integrated guide-wire 23 may be extended through the internal lumen of the medical device or may be removed with the guide-wire handle 29 so that therapeutic and diagnostic agents may be delivered. The linear extension guides 26 between the handle 25 of the external elongated tube and in the handle 27 of the internal elongated tube may be used to limit and measure extension 28 of the internal elongated tube. Extension measurements may be performed with commercially available sensors like optical encoders, potentiometers, or LVDTs. A similar rotation limit and measurement sensor may be incorporated into the device handle to limit and measure rotation between the device handles. Data from the distal device sensor 22 and from the handle rotation and extension sensors are transmitted to the system processor through the sterile data transmission cabling 30 . FIG. 6 provides additional views of the medical device with the internal elongated tube shown extended and curved 31 , and retracted 32 .
[0086] FIGS. 7-8 detail an embodiment for navigating a minimally invasive medical device within patient using an acquired three-dimensional anatomical image in conjunction with a live image. Both live and acquired anatomical images are shown in a display that is substantially aligned to the patient anatomy. In FIG. 7 , a live image is provided by a fluoroscopic imaging system 33 and the live fluoroscopic image is sent to the system processor 36 . A remote electromagnetic transmitter 35 , such as those commercially available from Northern Digital Incorporated (NDI) and Ascension Technology Corporation, is positioned outside the fluoroscopic image field to localize sensors on at least the medical device. As the display is repositioned to provide the optimum view for navigation of the medical device within the anatomical image, the acquired image is repositioned in the display to remain substantially aligned with the patient anatomy. Likewise, the live image is modified as the system processor 36 sends a command to the fluoroscopic positioning arm 34 so that the live image in the display remains aligned to the acquired image and substantially aligned to the patient anatomy. FIG. 8 shows the data flow from the sensors 37 on the patient and in the medical device to the system processor 39 . The system processor 39 collects the patient and device sensor data and the live image 40 , performs coordinate system transforms to unify the patient, image, and sensor coordinate systems, and presents the images of medical device and anatomy in the system display 38 .
[0087] FIG. 9 provides an overview of the procedure flow for a minimally invasive procedure using a stored image for navigation. The patient anatomy is imaged 41 with a non-invasive imaging modality like CT, MR, or rotational angiography. The imaged anatomy is stored and segmented into a three dimensional image, and borders and centerlines of vessels and conduits are calculated using commercially available software from vendors like Philips, Siemens, GE, Toshiba, Materialise, or Osirix. The image is transferred to the memory of the system processor and the image is registered 42 to the system coordinate system along with the patient and the medical device sensors. Registration of the image may be done by imaging the patient with an image-visible skin patch or with an externally anatomical marker placed on the patient. At least three separate points of the patch are visible in the image and then a position sensor is placed into the patch. The visible points on the patch may be selected on the displayed image and then the known distance from the visible patch fiducials is used to register the image to the patient position sensor. The patient position sensor and medical device position sensor are inherently registered because their positions are determined by the same sensing system. Next, the registered image is shown 43 above the patient in a manner substantially aligned to the patient anatomy. The medical device may be navigated 44 within the patient as the position sensor in the medical device is tracked and presented as an image icon within the image of the patient anatomy. The image of the anatomy and the image of the medical device may be shown with varying degrees of transparency to maximize the visibility of the device and anatomical images. The display, showing the image of the medical device within the image of the anatomy, may be repositioned 45 to enhance the viewing angle of the anatomy. As the display is moved, the image on the screen is updated to maintain substantial alignment between the displayed anatomical image and the patient anatomy.
[0088] FIGS. 10-11 describe specific algorithmic details of an embodiment for displaying a sensored medical device within images of anatomical conduits like blood vessels. The embodied medical device navigation system may be thought of like a GPS navigation system used in a car: a vehicle (the medical device) is shown on a map (the anatomical image) and is usually constrained to roads on the map (the conduits within the body). The expected path of the medical device within the patient may be programmed prior to the procedure much like a set of roads may be chosen for navigation between two locations using a car's GPS navigation system. The medical device position sensing signal has two independent sources of error: a process error band—position errors induced by sources like patient motion and misregistration—and a measurement error band—position errors inherent to the accuracy of the measurement system. Given a position measurement and knowledge of the anatomical structures, the system algorithm makes a best, safe attempt to represent the location of the medical device within the anatomical conduits. Ultimately, the algorithm decides to display the medical device in one of three positions relative to the anatomical image: within the same anatomical conduit where the device was previously shown, within a new anatomical conduit, or outside of an anatomical conduit. Predetermined distances and tolerances used in the algorithm may be preset in the software, chosen by the physician, or varied based on weighting from the pre-procedure path planning FIG. 10 shows an algorithm that uses the calculated boundaries of anatomical conduits to help determine where to display the medical device relative to the anatomical image. Initial 46 and current 47 positions of the medical device sensor are acquired and the velocity vector for the medical device is calculated 48 . The processor searches the anatomical image for the boundaries of the nearest anatomical conduit to the medical device sensor 49 . If the sensor position is within a conduit or within a predetermined distance to a conduit 50 and was previously displayed within the same conduit 52 , the image of the medical device is shown within that conduit 54 . The predetermined distance may be programmed into the algorithm based on the expected error bands for the medical device position sensing system, based on dynamic error updates from the sensor location system, or based on inputs from the operating physician. If the medical device sensor position is within a conduit or within a predetermined distance to a conduit 50 but is not within the same conduit as the previous algorithm cycle, then the velocity vector of the medical device sensor is checked to see whether the path of the sensor matches the path of the new conduit 53 and if the paths match, the medical device is displayed within the image of the new conduit 55 . If the medical device sensor is not within a conduit or a predetermined distance to a conduit, then the system searches for a next-nearest conduit within range 51 . If a conduit is found in range, conduit path is compared to the sensor path 53 and if the paths match, the medical device is displayed in the new conduit 55 . If another conduit is not found within range, the image of the medical device is displayed outside the conduit at the sensed position of the device 56 . Similarly, if the sensor is found to be within or near a conduit 50 but was not previously displayed within that conduit 52 and the path of the sensor does not match the path of the conduit 53 , the medical device is displayed outside the conduit at its sensed position 56 . FIG. 11 shows the application of the algorithm in FIG. 10 to various scenarios. Referring now to FIGS. 10 and 11 , the medical device is shown moving within a conduit 57 —the conduit shown is similar a femoral artery at the internal iliac branch. The initial medical device position is captured 61 . If the sensed position of the device is within the conduit 50 was previously displayed in the conduit 52 , the medical device is shown 54 in the image of the conduit 60 . If the sensed position of the device is outside the conduit but within a predetermined distance to the conduit 50 and was previously displayed in the conduit 52 , then the medical device is shown 59 within the conduit 54 . If the medical device sensor is outside the conduit and outside a predetermined distance to a conduit and another conduit is not within range 51 , then the medical device is displayed 58 at the actual sensed position 56 . The system may also track and record the current and previous sensor position measurements, by doing so for multiple measurements the sensor can be used to map the conduit itself in a breadcrumb type fashion.
[0089] FIGS. 12-13 describe an algorithm that is used within the preferred embodiment to actively characterize and reduce errors in the position sensor data. The algorithm uses known dynamic characteristics of the medical device and position sensor data from the dynamic behavior of the medical device to predict upcoming positions and error bands for the medical device position. A position sensor on the medical device may provide the dynamic behavior of the medical device, by estimating the known characteristics of motion for a hand-operated device, and by incorporating sensors such as accelerometers, encoders, and potentiometers in the handle of the medical device. The algorithm in FIG. 12 first acquires initial 62 and current 63 position data from the medical device position sensor. A Kalman Filter 64 technique, described by R. E. Kalman in 1960, is applied to predict the next sensor position and predict the error band. The Kalman algorithm then uses the data from the cycle to update gain, position estimate and error variables. The location of the medical device is shown with the anatomical image on the display 65 and the algorithmic cycle is repeated. As shown in FIG. 13 , as the initial 69 and current 68 sensor positions are collected, a predicted position and error band are calculated 67 . As data is collected, the predicted and actual positions converge and the error band decreases 66 . The Conduit Boundary algorithm in FIG. 10 and the Kalman Filter algorithm in FIG. 12 may be combined and the error band from the Kalman algorithm may be used to inform the predetermined distances from sensed position to conduit in the Conduit Boundary algorithm. Additionally, the Kalman algorithm predictions and error bands may be used to determine whether a conduit like a blood vessel is deforming within expected elastic limitations. If the Kalman convergence is robust, but the sensor is predicted to be outside the conduit, the conduit in the three-dimensional segmented anatomical image may be elastically deformed using a commercially available algorithm like Chai 3D with the GEL dynamics engine to model properties such as mass, inertia, elongation, flexion and torsion for the conduit membrane.
[0090] FIGS. 14-15 describe system embodiments for using at least one live fluoroscopic imaging source during minimally invasive procedures. In FIG. 14 , the fluoroscopic imaging detector 70 is located over the patient. The system display 71 is located near the fluoroscopic imaging detector close to the anatomy that is being imaged. The display support 72 holds the display over the patient and allows the user to modify the orientation of the display in at least one degree of motion. The display support is balanced so that the user may easily change the display position with very little force and may be made of materials like carbon fiber composite, which are transparent or translucent to fluoroscopy. The display stays in position if it is not moved by the user. The display position may be tracked with position sensors in each mechanical joint of the display support. Joint position sensors may include optical encoders like those supplied by Canon, US Digital, and Avago; magnetic encoders like those supplied by Timken and Austria Micro Systems, or potentiometers like those supplied by Honeywell and Sensofoil. Alternatively, the display position may be tracked with a free-space sensor located on or coupled to the display. Free-space position sensors include five and six degree-of-freedom electromagnetic sensors like those supplied by Northern Digital Incorporated and Ascension Technology Corporation or optical free-space sensors like those supplied by Northern Digital Incorporated. Data describing the position and orientation of the display is sent to the system processor 73 . The system processor is a standard computing system like those supplied by Dell or Hewlett Packard running an operating system like Windows or Linux. The system processor resolves the display position into coordinate system data that is common to the imaging system and sends the data to the imaging system. The display system commands motion of the patient table 74 and/or imaging support system 75 so that the viewing perspective of the live image matches the viewing perspective commanded by the display position. For example, if the user changes the display angle to change the viewing angle of the anatomy, the processor monitors the display angle change and a command is sent from the processor for the imaging system to change the angle of the fluoroscopic imaging detector. An input to translate the display may similarly be monitored and processed and would result in either the patient table or imaging detector panning over the patient to match the motion input at the display by the user. The motions at the display may be scaled within the processor to result in a scaled command to move the imaging source. For example, a 15 degree change in the display angle position may be scaled in the processor at a 1.5:1 factor to result in a 22.5 degree angle change at the imaging system. The scaling factors may be chosen to fit the anatomical workspace so that any resulting mismatch between display angle and imaging angle is well-tolerated by the user. Typically, users tolerate an angular mismatch of up to 30 degrees and translational mismatches of up to 24 inches.
[0091] FIG. 15 shows the generic data flow as the live imaging source 76 sends a live image to the processor 77 . The processor formats the image and immediately sends it to the system display 78 . The display position sensor tracks motion of the display. The display position tracking data is processed by the processor that commands the fluoroscopic equipment to move in such a manner that the image on the display remains substantially aligned with the patient. The processor scales the display position change and converts the position to the same coordinate system as the live imaging source before sending the imaging position that matches the display position to the imaging source.
[0092] FIG. 16 is a flow chart for a procedure using live imaging. At the start of the procedure, the display and imaging system are aligned during a system alignment step 79 . Typically, the display is positioned over the patient anatomy and the display angle is manually set to match the angle of the imaging source. A button is pressed to tell the processor that the display and imaging source are in their aligned start positions. Then the patient anatomy is imaged 80 with the live imaging source. The live imaging source is often fluoroscopy, but may be other common sources of live images like an endoscope or ultrasound probe. The live image is displayed 81 on the system display which is substantially rotationally aligned with the patient's anatomy of interest as the user navigates 82 the medical device within the patient as a live image of the device within the anatomy is shown on the system display. As the user repositions the display 83 to change the view of the device and the anatomy, the system commands the imaging source to similarly reposition in order to achieve the viewing angle and position commanded by the user.
[0093] FIG. 17 is a diagram of the same system shown in FIG. 14 with the addition of an ultrasound live image source. The ultrasound support arm 85 is a servo-actuated four-bar linkage system with a mechanical remote center about the contact point between the ultrasound probe 84 and the patient. As the user changes the position of the display, the system calculates an appropriate change in the viewing angle of the ultrasound probe and commands the support arm for the ultrasound probe to reposition so that the ultrasound viewing angle and the display position are substantially co-aligned.
[0094] FIG. 18 shows an embodiment of the patient reference sensor. The sensor is affixed to the patient with a skin adhesive layer 87 . A rigid plastic disk 88 —made of a polymer such as polycarbonate, polypropylene, or nylon—is attached on top of the skin adhesive layer. At least three image-opaque marker spheres 86 —in this case MR opaque 4 mm markers containing Gadolinium—are mounted at known unique radial and angular distances from the center of the patch. After imaging is conducted, a electromagnetic coil sensor 89 , such as the Ascension model 1080 6-DOF sensor or Northern Digital Incorporated Aurora 6-DOF sensor, may be mounted in a precision snap-fit receptacle in the patch 91 . A data transmission cable 90 connects the sensor to the system. Clicking a mouse or other user interface on the visible markers in the segmented or unsegmented anatomical image tells the system the location of the patch, and by extension the sensor, relative to the anatomy.
[0095] FIG. 19 shows an embodiment of architecture 92 of a system for displaying an image 95 on a movable display 93 that interacts with a user interface 97 . In this embodiment a movable display screen 93 is presented to a user 94 . A user 94 can view the image 95 on the display 93 and can move the display in at least one degree of freedom. The image 95 shown on the display 93 is coupled to the position and/or orientation 98 of the display such that moving the display changes the position and/or orientation of the image displayed on the screen. Additionally, the user has an interface via an input device 97 , like a foot pedal, palm, finger, or thumb switch, or an active element of the screen itself using touch screen technology, to modify the coupling of the display position and/or orientation to the image. The input device 97 sends signals 93 to the computer 99 . Additional signals 96 are sent to the computer to communicate the display's position and/or orientation. The image data 100 is also sent to the computer 99 . The image data 100 can be real time x-ray, Ultrasound, video images or previously acquired images or image data sets such as CT, MRI or rotational angiography. Individual programmable parameters 103 are also sent to the computer. These parameters modify the way the image is displayed and may include parameters to set the scaling of the image, the transparency of the image, the texture of the image, the reflectivity of image, the color of the image, the mechanical properties of the image, the resolution of the image, and the digital size of the image. In turn, the computer receives the image file 101 , the programmable parameters 103 , the display position data 96 and the input status 98 and sends an image data set 102 to the display 93 . The screen 93 then receives the image data set 102 and an image 95 is displayed to the user 94 .
[0096] FIG. 20 shows an event flow chart 104 for decoupling the relationship of the display position to image for re-positioning the display independently of the image using an input device 110 . In the embodiment, the image displayed on the screen is coupled to the screen's position and orientation. Decoupling the image position and/or orientation from the display position and orientation is heretofore referred to as “clutching” which is initiated by a decoupling event and ended by a recoupling event. The term “clutch” as used herein encompasses signal processing, data processing, and/or input techniques which allow, for example, a display to be repositioned while the display position is continually tracked by the processor and at least some of the relationships are temporarily disassociated from the algorithm which is actively updating the image display. For example, a user may 1) activate an input which temporarily disassociates linear translation from the active image position update, 2) move the display, 3) have the image in the display continue to update in rotational orientation but not in translation, and then 4) deactivate the input which temporarily disassociated linear translation from the active image update so that any further manipulations of the display in linear translation result in an image update in the translation axes. As shown, a user can initiate a decoupling event 105 by interacting with the system in some fashion, for instance by depressing a switch. This event 105 is sent to the computer, which, in turn, locks the image in its current state, and the relationship between the display position and/or orientation to the image is broken 106 . In this state the display may be repositioned 109 without affecting the displayed image. Once the display is moved to its new position and/or orientation, the switch is released 109 . The relationship between the display position and image is then re-established 108 . The image is now displayed as a function of the relative motion from this newly repositioned location, as if the display had not been re-positioned. In an alternative explanation of this feature; the user changes the manner in which the image is coupled to the display position and/or the display orientation by introducing location offsets and orientation offsets. Those offsets correspond to the change in position and/or change in orientation of the display when the display is moved in a decoupled state. Preprogrammed values may be included to limit the amount of motion between the first and second positions of the image. During screen repositioning the amount of motion is tracked 111 and compared against limits 112 . During screen repositioning, once these limits have been reached 113 , the image and display positional relationship will be re-established. To substantially maintain the image to patient relationship and maintain the intuitive feel, the maximum allowable discrepancies are approximately 30 degrees in rotation and 24 inches in position.
[0097] FIG. 21 shows an event flow chart 114 for an alternate way to de-couple at least 1 position or orientation axis of the display-image relationship. It may be advantageous from time to time to temporarily decouple the image orientation from the display orientation without moving the display. For instance, the user could actuate 115 using an input device 121 such as a thumb wheel, joystick, or other mechanical device to send a signal to the computer to decouple 116 the image from the display position and rotate, pan, or zoom the image as displayed on the display screen. In the case of touch-screens, the user could use single or multiple fingers to rotate, pan, or zoom the image to a new position. The image would then be correspondingly displaced 120 while the signal or signals are being received by the computer. Once the user releases 117 the thumbwheel, joystick, or touch-screen, the image is returned 118 to its original position and orientation and the image-to-display position relationship is re-established 119 as if the display had not been re-positioned.
[0098] FIG. 22 shows an example of a translational offset 127 between the imaging system 122 and display 125 . In this example, the fluoroscopic imager 136 is placed over the patient's chest 124 . The display 125 is placed over the patient's pelvis. This allows the fluoroscopic imaging system 122 to have a clear unimpeded view of the patient's anatomy. Placing the display in the field of view of the imaging system may interfere with the images produced, especially if the display is not fluoroscopically transparent. The image 126 presented to the user is of the patient's chest and is aligned with the patient in all axes and with an offset in the ‘x’ 128 axis. This offset allows for unimpeded live imaging while maintaining a substantially aligned image. Additionally, the display in this position relative to the fluoroscopy system acts as a radiation shield for the user (not shown) positioned at the display 125 .
[0099] FIG. 23 shows a simple architecture 129 for performing image motion scaling. For the purpose of simplicity the above descriptions have largely assumed that the displayed image is a virtual window into the patient. As such there is an inherent 1:1 scaling factor with all aspects of the screen's position and orientation to the image. This 1:1 scaling factor, although reasonable and logical, is, in use, occasionally impractical. The architecture 129 shown allows for user set scaling factors 130 , namely fx, fy, fz, fp, fr, fy for scaling motion in the x, y, z, pitch, roll, and yaw axes respectively. The user may enter these scalars 131 into the computer 132 . The display 133 position is localized in x, y, z, pitch, roll, and yaw and has the coordinates 134 . The computer 132 accordingly multiplies the received system display coordinates 134 , by the scalars 131 and displays the image in accordance to the scaled values 135 . As an example, if the value of fx is 2 and the screen position is moved 1 mm, then the image will move 2 mm on the screen. As another example if the value of fp is 1.5 and the screen is rotated in the pitch direction by 30 degrees, the image will be rotated in the pitch direction by 45 degrees.
[0100] FIG. 24 presents an embodiment for positioning a medical image display 138 . The display 138 is supported by an arm 139 which is comprised of a movable configuration of linked joints. The arm 139 is mounted to a cart 140 that has lockable wheels 141 so that the arm and display may be placed in different locations for different surgical procedures. The display 138 is presented to the user 142 at a location that is between the user 142 and the patient 137 . The patient 137 is lying on a table 136 . In this embodiment, the images displayed on the screen 138 may be obtained from a variety of medical imaging sources, including pre-operative and intra-operative images from CT, MRI PET, and rotational angiography, or live images such as ultrasound, fluoroscopy, or endoscopy. In this embodiment, the display 138 is located in the surgical field and may be covered by a sterile drape (not shown for clarity) so that it may be manipulated directly by the operating physician. The display 138 and support arm 139 are movable to reposition the screen during the medical procedure and the position of the display and arm may be tracked during the procedure.
[0101] FIG. 25 presents a larger view of the support arm with the cart removed for clarity. In this embodiment, the display 151 , is mounted such that the display can be rotated about its center of gravity. Encoder 154 tracks the angular orientation of the display 151 . Support links 157 and 156 are pivotally coupled about a horizontal axis at joint 150 . Link 156 is pivotally coupled to a horizontal axis at joint 149 on vertical shaft 155 . Vertical shaft 155 is supported by bearings 147 and 148 which allow free rotational motion of the shaft. Bearings 147 and 148 are supported by the cart which is depicted in previous FIG. 24 . Counterweight 144 provides counterbalancing of arm 157 and display 151 and is coupled via a tension tendon, like rope or wire rope, 152 that runs over joints 149 and 150 . Adjustable brakes may be included at joints 149 and 150 to adjust the amount of force required to reposition the display 151 . In some embodiments the brakes may be made from Teflon, PPS, or UHMW PE. These materials are the preferred choice of brake materials because their coefficients of static frictions are close to their coefficients of dynamic friction, allowing for smooth repositioning. Counterweight 143 provides counterbalancing for links 156 , 157 , and display 151 and is coupled via a tension tendon 153 that runs over joint 149 . Inclinometers 145 and 146 track the angular position on the links 156 and 157 via the coupled nature provided by the tension tendons. Encoder 158 tracks the rotational position of the base of vertical link 155 . The position of the display is determined in a coordinate system affixed to the base of the cart using the signals from the encoders and inclinometers and knowing the fixed length of the links.
[0102] FIG. 26 shows an isometric view the display support structure with user input button 159 .
[0103] FIGS. 27 and 28 show an alternate configuration of a display support structure. In this embodiment the support structure has a base 160 that is mounted to the table 161 . The support structure is mounted to a horizontal leadscrew 162 that is driven by servomotor 163 . Link 164 pivots about joint 165 and can travel along a horizontal axis. Servomotor 168 is connected to link 172 via belt 169 . Also shown is servomotor 170 connected to belt 171 which is connected to link 173 via a tension tendon as shown in FIG. 25 . The servomotors are positioned away from the joint and move with the link to which they are attached and may be positioned to counterbalance the display support structure. In this fashion, the weight of the servomotor reduces the amount of power needed to move the linkage. Motion along the linear axis may be controlled with force sensors that sense the users intended motion and send commands to the servomotor accordingly. Alternatively, motion may be controlled with a joystick or other user input. Additionally, the leadscrew and motor combination may be used to compensate for table motion in the same direction, keeping the display positioned where the physician is standing even thought the table is moved to reposition the patient. Another embodiment replaces the leadscrew and servomotor with a simple linear bearing. Of course, it can be easily imagined by anyone skilled in the art that linear motors, belts or other methods to motorize a linear actuator may replace the leadscrew and servomotor.
[0104] FIG. 29 shows an embodiment where an optical tracking system 174 tracks the position of the table marker 175 , the display marker 176 , and the fluoroscopy imaging system marker 177 . In addition, an electromagnetic tracking system 178 tracks the position of a patient reference marker 179 attached to the patient 180 and a localization sensor attached distal end of a surgical tool 181 . It should be noted that any combination of localization systems may be employed to track the various components of the systems. The configuration shown is exemplary and it should be understood that variations of this example exist and may be equally suitable for accomplishing desired results.
[0105] FIG. 30 shows an alternative embodiment for display support arm where the support arm is comprised of a five axis multi-joint device with motion along the table at 186 , motion about vertical axis 185 , motion about horizontal axis 184 , motion about horizontal axis 186 and motion 182 about the display center of gravity. The design provides a high degree of positioning flexibility in all five directions. Additionally, all non-vertical axes pass through the CG of the display. This allows for a lightweight support arm that does not require counterbalancing.
[0106] FIG. 31 shows an embodiment of a three link SCARA type arm with an encoded linear vertical axis 187 , four vertical encoded axes 188 and a gimbal joint 189 under the display.
[0107] FIG. 32 shows the support arm of FIG. 31 mounted on a cart 190 . The cart allows the display to be positioned in a variety of places within a single room, or in different rooms.
[0108] FIG. 33 . Shows a simple embodiment of a sensored medical guidewire with the outer jacketing removed for clarity. Guidewires are used in minimally invasive procedures to navigate through the vascular atraumatically. Although many sizes of wires are available, a typical guidewire for simple navigation in the arterial and venous trunk is an 0.035″ polymer coated wire like a Terumo Glidewire. A Glidewire has a tapered solid core with a hydrophilic coating. The tapered core allows for good torque transmission, low bending stiffness near the distal end and the coating allows for smooth advancement. Typically, core materials are made from metals, like stainless steel, spring steel, or Nitinol. FIG. 33 shows an EM sensor 191 with its conductive wires 192 traversing down the shaft of the wire, from the distal, to the proximal end. Also shown is a second sensor 194 with its conductive wires 196 helically wrapping around the tapered core 193 . The tapered core 193 extends from at least the distal tip of sensor 191 to the proximal end of sensor 194 . It should be noted that wire pairs 192 and 196 are preferentially twisted pairs to reduce electrical noise. Also shown is helical cut 197 , which allows the wire pairs to wrap down the shaft with minimal increase to the overall construction diameter. The helical cut also preserves the radially symmetric geometry needed for a good performing guide wire with uniform twist. It should be understood that a helical groove could also be cut into the tapered core 193 allowing for wires 192 to run through the center of sensor 194 . In all cases at least the portion of the tapered core within the length of the sensors 191 and 194 is comprised of a material of high magnetic permeability such as MuMetal, or permalloy. Finally, the construct may be jacketed with a hydrophilic coating.
[0109] FIG. 34 shows a detailed section of the connector 199 . Wires from the sensors are connected to a connector 199 . Connector 199 is constructed with concentric conductive cylinders separated by an insulation layer. The lengths of the cylinders get progressively shorter as they get larger in diameter. The layering of concentric cylinders can be repeated until the needed number of contacts is created. In this example, 4 contacts are needed and shown. This construction allows for a mating connection to rotate along the axis of the wire. This construction also allows for connecting multiple signals within the diameter of the guidewire, in this case 0.035″. A series of conductive bands may alternatively be used for connecting multiple signals within the diameter of the guidewire, in this case 0.035″. | The invention comprises a virtual window system that creates a visual coherency between the image of the patient and his or her anatomy and the patient by aligning the image of the patient anatomy on the display to the patient and presenting the image to the user that feels is if the user is looking directly into the patient through the display. The invention is designed to also display medical devices, such as a minimally invasive tool. The system substantially unifies the coordinate systems of the patient, the medical device, the display, and the physician's hands. The invention creates a visual coherency between the motion of the medical device in the image and the motion of the physician's hands manipulating the device. This invention also creates a visual coherency between the motion of the image in the display and display. | 5 |
FIELD OF THE INVENTION
One embodiment of the present invention is directed generally toward friction stir welding and surface processing and, more particularly, toward portable apparatus for use in friction stir welding and surface processing processes.
BACKGROUND OF THE INVENTION
Friction Stir Welding machines currently in use are normally designed for stationary installation in a building where the housing for holding the tool and the motor for spinning the tool are located. The type of weld joint being made such as butt, lap, etc., and the number of welds being made such as single double, etc., is determined by the tool being used.
SUMMARY OF THE INVENTION
The portable friction stir welding machine disclosed herein can be configured as a crawler having a top member which supports a motor, such as a torque motor, having a rotary shaft for rotating a Friction Stir Welding tool and a drive mechanism for pulling the crawler along a predefined weld path of work pieces. The crawler can include at least two physically separated members where one member is adapted to be located above the work pieces and the other member is adapted to be located below the work pieces. The friction stir welding tool for effecting the weld is rotatably coupled to each member of the crawler and effectively restricts axial displacement of, for example, the two physically separate members relative to each other. Thus, it is the friction stir welding tool which is rotatably coupled to each of the two members of the crawler and prevents the at least two members from being displaced axially relative to each other.
Rotational displacement of the at least two members relative to each other and/or relative to the work pieces can be provided by rails or guides located on one or both of the work pieces. Depending on the method used to prevent rotational displacement of the crawler relative to the work pieces, the type of rotating tool that is being used, and whether the weld being made starts and ends at the edges of the work pieces or in from the edges of the work pieces, one or more of the following functions may be required while making a weld: the speed that the crawler advances along the work piece, the rotational speed of the tool, steering the crawler, etc.
One embodiment of the present invention is a structure which is both easy to transport and can be moved to a work site rather than moving the work pieces to a building where a stationary Friction Stir Welding machine is located.
The foregoing has outlined, rather broadly, an embodiment of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject matter of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention and that such other structures do not depart from the spirit and scope of the invention in its broadest form.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claim, and the accompanying drawings in which similar parts have similar reference numerals where:
FIG. 1 is a perspective view of one embodiment of a friction stir welding assemblage of the present invention having a housing with three separate members, where each member has two sections, coupled to a common tool;
FIG. 1A is a side sectional view of the embodiment of FIG. 1 showing two work pieces being welded.
FIG. 1B is a side sectional view of clamping preloading member in one of the members of the crawler.
FIG. 2 is a side sectional view of another embodiment of a friction stir welding assemblage having a housing with two separate members, where each member has two sections, coupled to a common tool;
FIG. 3 is a front sectional view of the embodiment of FIG. 2 ;
FIG. 4 is a side sectional view of still another embodiment of a friction stir welding assemblage having a housing with one member having two sections coupled to a tool;
FIG. 5 is a perspective view of a friction stir welding tool coupled to a guide on a work piece to prevent rotation of the housing;
FIGS. 6-8 show various friction stir welding tools which can be used to make welds; and
FIGS. 9-20 show various work piece configurations and types of welds which can be made with the apparatus here disclosed.
DETAILED DESCRIPTION
Friction Stir Welding (FSW) is a process which can be used to weld together a wide variety of materials and their alloys such as aluminum, copper, iron, steel, stainless steel, etc. The weld is formed by plunging a rotating, non-consumable pin type tool into work pieces that are to be welded together with a butt or lap weld. During the welding process, as the pin type tool initially plunges into the work pieces at the weld line, the material is frictionally heated and plasticized at a temperature below that of the melting temperature and typically within the material's forging temperature range. When the metal becomes sufficiently soft and plastic, and the tool reaches the appropriate penetration depth, the tool is advanced along a weld line. As the tool is moved along the work pieces, metal flows to the back of the pin type tool where it is mixed behind the tool and consolidates while it cools to create a sound metallurgical bond. Friction stir welding, in addition to being used to join together similar metals, can also be used to join dissimilar metals or plastics or other materials that will soften and consolidate under frictional heating to become integrally connected. Friction stir welding can be used to make butt joints, corner joints, lap joints and other types of joints, as well as being used to repair cracks in a given material and for forming a hollow section, such as a round, square or rectangular tube.
The friction stir welding process is implemented with a FSW pin type tool which can have a single pin and a shoulder which contacts a top surface of the material being joined. An anvil which contacts the bottom surface of the work pieces opposite the FSW pin type tool can be used to prevent plasticized material from flowing out of the bottom of the weld during the welding process to provide a smooth weld surface. In some applications, the pin type tool may not include the anvil.
Referring to FIG. 1 , there is shown a perspective view of one embodiment of the present invention having a housing of three separate members where each member is composed of two half sections coupled to a friction stir welding tool for making friction stir type of welds. Notwithstanding the illustrations in FIGS. 1-5 and the disclosure of the embodiment that describes in detail three separate members, it is within the scope and contemplation of this invention that the number of members, along with associated cooperating features, can be as many or as few as necessary to weld two or more work pieces together per design or customer requirements. Therefore, nothing disclosed herein is intended to limit the claimed invention.
In the present invention, the housing, hereinafter referred to as crawler 200 , when making a weld, engages rail members at or near the edges of the work pieces (discussed in detail below). The rail members can be raised member or channels which slidably engage a receiving member, such as a slot or a side wall, in the crawler to provide guiding and torque compensation for the crawler during the welding process. The crawler can include, for example, upper member 201 , intermediate member 202 , and lower member 203 . These members can be composed of a semi-yieldable material such as a plastic, or a rigid material such as cast iron or other equivalent material where each of the three members of the crawler is split to provide a front section and a back section. Upper member 201 of the crawler consists of two substantially similar sections, front section 201 A and back section 201 B. Back section 201 B can have, for example, four clearance openings 204 for receiving threaded fasteners (not shown) that pass through clearance openings 204 and thread into threaded openings 205 in front section 201 A to lock or secure the two sections 201 A, 201 B together to form member 201 . Each section has a semi circular shaped cut out 206 for receiving a split sleeve bearing 207 or a race and ball bearings. Each member also includes cut out sections 500 having side walls 501 for receiving raised rails or channels (see FIGS. 9-20 ) which may be formed by extrusion on the work pieces such as, for example, aluminum sheet work pieces, where the rails are adapted to slidably engage the members to provide guiding, alignment and torque compensation for the members during the making of a weld. In those instances where the rails 701 , see FIG. 9 , in the work pieces are channels 712 , see FIG. 15 , then the crawler may have wheels (not shown) or rigid projections (not shown) which fit within the channels 712 to provide guiding and torque compensation for the crawler while a weld is being made. Clamping of the crawler to the work pieces can be provided by rails or channels which are sized to have a close fit with the engaging parts in the members or with spring members located in the crawler and both above and below the work pieces being joined.
Referring to FIG. 1B , member 530 which is located in cutout section 500 is positioned to engage rail 701 on the work piece and is urged by spring 532 to move the work piece toward the right to butt against the work piece to which it is to be joined. Also, a second spring 534 is coupled to urge member 530 to move down to contact the work piece. The member 534 can be provided to contact only the top surface of each work piece or a member 534 can be provided for both the top and bottom surfaces of each work piece to both urge the work pieces toward each other to preload the work pieces and to clamp the crawler to the work pieces. In another embodiment, the springs are eliminated and the members are either sized or adjusted to provide a crawler that has a close fit with the work pieces such that the crawler holds the work pieces securely near each other with sufficient force to prevent the tool, during the welding process, from pushing the work pieces apart and prevent the counter torque from rotating the crawler. It is to be noted that the structure disclosed to urge the work pieces together and to clamp the crawler to the work pieces can compensate for work pieces that have uneven edges and/or varying thicknesses.
Thus, by the action of the member 530 , the crawler, by being both above and below the work pieces, clamps itself to the work pieces as a weld joint is being made. FIGS. 9-20 show pre-weld and post weld work pieces which can be of a desired material such as aluminum and which have rails or channels at or near their edges to provide guiding and torque compensation for the crawler.
As is here described for the embodiment shown in FIG. 1 , it is to be understood that for each embodiment which is disclosed hereinafter, the spacing between adjacent upper and intermediate, and intermediate and lower members of the crawler can be varied to receive work pieces that have different thicknesses. In addition, the members of the crawler have a slot or a rigid projection positioned to slidably engage a rail or a channel on a work piece during the welding process to provide guiding, alignment, fixturing and torque compensation for the crawler in addition to positioning and/or preloading the work pieces by urging the edges of the work pieces toward each other. Also, clamping of the crawler to the work pieces is provided by close fitting or spring loaded members located within the crawler which slidably engage and press against the surfaces of the work pieces during the welding process. Further, for each embodiment disclosed herein, the rail on each work piece can be a raised member or it can be a channel, and the rail can trace a path which is straight, curved or a combination of both. During the welding process, the crawler engages the rails on the work pieces to urge the work pieces to butt against each other to provide a desired preload force to the work pieces during and after the welding process.
Additionally, the work pieces can be of aluminum and the rail member can be formed by extrusion or other type of metal working process. It is here noted that, to avoid having duplicate and repetitive paragraphs in the description, this paragraph is not being repeated for each embodiment hereinafter disclosed, and it is understood that this paragraph of the invention is a part of the description of each embodiment the same as it would be if it were actually included in the description of each embodiment.
The top surface 201 T of the front 201 A and back 201 B sections of the upper member 201 has four threaded openings 300 for receiving four threaded fasteners (not shown) for securing a motor, such as a torque motor 308 (servo, hydraulic, pneumatic or electric), to the upper member 201 when the front 201 A and back 201 B sections are secured together with threaded fasteners as disclosed above. The front and back surfaces of each member are similar. Therefore, a view of the front surfaces of members 201 , 202 , 203 of FIG. 1 is not disclosed. The front surface of the front section 201 A and the back surface 301 of the back section 201 B of the upper member 201 can have four threaded openings (not shown) for receiving four threaded fasteners (not shown) for securing a pull member 210 to the front 201 A and back 201 B sections of upper member 201 . Pull member 210 is provided to receive a pull cable (shown attached to front section 202 A) to pull the crawler 200 at a predetermined speed along work pieces being welded.
Intermediate member 202 consists of two substantially similar sections, front section 202 A and back section 202 B. Back section 202 B has four clearance openings 208 for receiving threaded fasteners (not shown) which pass through clearance openings 208 and thread into threaded openings 209 in front section 202 A to lock or secure the two sections 202 A, 202 B together to form member 202 . Each section 202 A, 202 B has a semi-circular shaped cut out 206 for receiving a split sleeve bearing 207 or race with ball bearings. Each member also has a cutout 500 adapted to engage rails or projecting members (not shown) to engage channels on the work pieces. The front and rear surfaces of the intermediate member 202 has four threaded openings (not shown) for receiving threaded fasteners (not shown) for securing pull members 210 to the intermediate member 202 . The pull members 210 are provided to receive a pull cable 202 P used to pull the crawler 200 at a predetermined speed along work pieces being welded.
Lower member 203 consists of two substantially similar sections, front section 203 A and back section 203 B. Back section 203 B has four clearance openings 211 for receiving threaded fasteners (not shown) which pass through the clearance openings 211 and thread into threaded openings 212 in front section 203 A to lock or secure the two sections 203 A, 203 B together to form member 203 . Each section has a semi circular shaped cut out 206 for receiving a split sleeve bearing 207 or a race with ball or roller bearings and cut outs 500 or projecting members (not shown) for engaging rails or channels on the work pieces. The front surface (not shown) and rear surface of the lower member 203 can have four threaded openings (not shown) for receiving threaded fasteners (not shown) for securing pull members 210 to the lower member The pull members 210 are provided to receive a pull cable similar to pull cable 201 P to pull the crawler 200 at a predetermined speed along work pieces being welded.
Continuing with FIG. 1 , prior to joining the front 201 A, 202 A, 203 A and back 201 B, 202 B, 203 B sections of the upper 201 , intermediate 202 and lower 203 members together, and subsequent to inserting the split sleeve bearings 207 into respective cutouts 206 in the upper 201 , intermediate 202 and lower 203 members, a replaceable Friction Stir Welding (FSW) tool 213 is fitted in place in the three members. As described in detail below, the FSW tool 213 disclosed herein can be configured to make a single weld or two welds simultaneously. However, an embodiment with more than two members is contemplated to be within the scope of the invention as discussed herein. The tool 213 can be a single member (as shown) without any removable sections, or it can be made of two or more separate sections (not shown) that can be coupled together with, for example, a threaded pin which engages a threaded opening to form a continuous tool. When the tool is made of two or more sections, the threads on the threaded pin of one section are designed to thread into a threaded opening in the other section as the tool is being rotated.
One embodiment of the present invention is shown for use with a FSW tool having three bearing surfaces adapted to rotatably engage the three split sleeve bearings 207 in the front and back sections of the three members 201 , 202 , 203 . When the FSW tool 213 is located in the upper 201 , intermediate 202 , and lower members 203 , an upper FSW bobbin 216 is aligned with the space 201 X between the upper 201 and intermediate 202 members; and a lower FSW bobbin 217 is aligned with the space 201 Y between the intermediate 202 and lower 203 members. The spaces 201 Y, 201 X, as explained below, are determined by the relationship of various dimensions relative to each other such as the spacing between the bearings on the FSW tool, the spacing between the semi circular shaped cut outs 206 in the member 201 , 202 , 203 , and the spacing between the semi circular cut outs 206 in each member and the physical end of each member at the space. However, in practice, where the members of the crawler are available for use, it is the tool which determines the spacing between the members. Thus, different tools can be used to provide the proper spacing between crawler members to allow the crawler to be used with work pieces of different thicknesses.
After the front and back sections of the three members 201 , 202 , 203 are joined together around the replaceable FSW tool to entrain or encapsulate the FSW tool 213 within crawler 200 , the torque motor 308 is placed on the top surface 201 T of the upper member 201 to engage a splined engagement pin 214 located at the end of the FSW tool 213 , which projects above the top surface 201 T of the upper member 201 . The torque motor 308 is then attached to threaded openings 300 in the upper member 201 with threaded fasteners (not shown). At this time, the friction stir welding tool is ready to join at least two work pieces together.
In operation, where two welds are to be made simultaneously, see FIG. 1A , a first pair of work pieces 400 that are to be joined are positioned edge to edge in the space 201 Y between the front sections of the lower 203 and intermediate 202 members respectively. A second pair of work pieces 402 that are to be joined are positioned edge to edge in the space 201 X between the front sections of the intermediate 202 and upper 201 members respectively. Prior to starting the welding process, replaceable FSW tool 213 was inserted into the split sleeve bearings 207 located in the front sections 201 A, 202 A, 203 A, and the back sections 201 B, 202 B, 203 B of the three members 201 , 202 , 203 were attached to the front members 201 A, 202 A, 203 A. Immediately prior to making the weld, the lower bobbin 217 of the FSW tool 213 is located at the weld seam (defined by the interface/contact of the two work pieces) of the first pair of work pieces 400 , and the upper bobbin 216 of the FSW tool 213 is located at the weld seam of the second pair of work pieces 402 , and generally along the center line (CL). A pull cable (not shown) is attached to pull member (not shown) on, for example, the intermediate member 202 and is used to pull the crawler 200 along the rail 425 on the work pieces 400 , 402 within cutouts 500 having side walls 501 that slidably engage rails 425 as the FSW tool is rotating and traversing along the weld seam.
An alternate embodiment not shown includes work pieces having channels and slidably engaging projections formed within or in place of cutouts 500 . It is here noted that the rails on the work pieces provide guiding, alignment and torque compensation for the crawler 200 . In another embodiment, pull cables (not shown) can be attached to each of the three members 201 , 202 , 203 to advance the crawler along the work pieces.
Now referring to FIG. 2 there is shown a side sectional view of another embodiment of the present invention having a crawler 200 A with two separate members 201 , 203 coupled to a FSW tool 213 A. The embodiment shown in FIG. 2 is similar to the embodiment of FIG. 1 , except the embodiment of FIG. 2 does not include an intermediate member 202 as shown in FIG. 1 . The various parts of FIG. 2 which are similar to those parts of FIG. 1 have been given the same reference numerals and some of the parts of FIG. 1 may not be shown in FIG. 2 . Upper member 201 and lower member 203 can be composed of a semi-flexible material such as a yieldable plastic or a rigid material such as cast Iron or other similar material and each member is composed of two substantially similar half sections to provide a front section 201 A, 203 A and a back section 201 B, 203 B: Back section 201 B has four clearance openings for receiving threaded fasteners which pass through the clearance openings and thread into threaded openings in front section 201 A to join the two sections together as described above for the embodiment of FIG. 1 . Each section has a semi circular shaped cut out 206 for receiving a split sleeve bearing 207 or race with ball bearings and cutouts 219 for engaging rails on the work pieces. The top surface of the front and back sections of the upper member 201 has four threaded openings (not shown) for receiving threaded fasteners (not shown) for securing a motor, such as a torque motor 308 to the upper member 201 when the front and back sections are secured together. The front surface and rear surface of the upper member 201 can have four threaded openings (not shown) for receiving threaded fasteners (not shown) which secure pull members 210 to the upper member 201 . The pull members are provided to receive a pull cable 201 P to pull the crawler 200 at a predetermined speed along work pieces being welded.
Lower member 203 consists of two substantially similar sections, front section 203 A and back section 203 B. Back section 203 B has four clearance openings (not shown) for receiving threaded fasteners (not shown) which pass through the clearance openings and thread into threaded openings (not shown) in front section 203 A to join the two sections together. Each section has a semi circular shaped cut out 206 for receiving a split sleeve bearing 207 or a race with ball bearings and cutouts for engaging rails or channels on the work pieces. The front and back sections of the lower member have four threaded openings (not shown) for receiving threaded fasteners (not shown) for securing pull members 210 . The pull members are provided to receive a pull cable 201 P used to pull the crawler at a predetermined speed along work pieces being welded.
Prior to joining the front and back sections of the upper 201 and lower 203 members together, and subsequent to inserting the split sleeve bearings 207 into respective cutouts 206 in the upper 201 and lower 203 members, a Friction Stir Welding (FSW) tool 213 is first fitted in place in either the front or back section. The front and back sections of the two members 201 , 203 are then secured together to envelop or entrap the FSW tool 213 . At this time a gap 201 X is formed between members 201 , 203 which is slightly larger than the thickness of the work pieces 402 . Thus, when the dimensions of the crawler are fixed to receive and operate with various tool, the spacing 201 X between the members 201 , 203 , is determined by the spacing between the bearings on the tool.
The FSW tool 213 A in this embodiment is configured to make one weld. The tool 213 can be a single member without any removable sections, or it can be made of two or more separate sections which can be coupled together with at least one threaded pin which engages a threaded opening in another section to form a continuous tool. When the tool is made of two or more sections, the threads on the threaded pin of one section are designed to thread into the threaded opening in the other section as the tool is being rotated.
The FSW tool 213 A shown in the embodiment of FIG. 2 has two separate bearing surfaces 206 A adapted to rotatably engage two split sleeve bearings 207 or races with ball or roller bearings in the front 201 A, 203 A and back 201 B, 203 B sections of the two members 201 , 203 . When the FSW tool 213 A is located in the upper and lower members, a single FSW bobbin 218 is aligned with the space 201 X between the upper 201 and lower 203 members as described above.
In operation, when a weld is to be made, a pair of work pieces 402 , which can have rails 701 as shown in FIG. 9 which are to be joined are positioned edge to edge between the front sections of the upper 201 and lower 203 members. At this time the FSW bobbin 218 of the tool 213 is located at the beginning of the weld joint of the work pieces and a pull cable 201 P is attached to the upper member and is used to pull the crawler 200 along the rails 701 on the work pieces 700 as the FSW tool is rotating. In another embodiment, a pull cable 202 P can be attached to each of the two members 201 , 203 , instead of to only one member to advance the crawler along the work pieces. In another embodiment, a threaded shaft connected to the crawler can be used to advance the crawler along the work pieces as a weld is being made. In each embodiment, sensors can be provided to control the speed of advance of the crawler and other parameters which may be required as a weld is being made.
FIG. 3 is a front partial sectional view of the embodiment of FIG. 2 . As noted above, in the various embodiments, the space 201 X for the work pieces which is located between adjacent members 201 , 203 is determined by design of the tool when the crawler is made with dimensions which have been standardized.
FIG. 4 , is a side partial sectional view of a friction stir welding crawler 200 B having one member 201 coupled to a friction stir welding tool 213 B. See the description above of FIG. 1 for a detailed description of the various features of FIG. 4 which are common with those of FIG. 1 . The member 201 can be composed of a semi-flexible material such as a plastic or a rigid material such as cast iron or other equivalent material and is split to provide two substantially similar sections, a front section 201 A and a back section 201 B. Back section 201 B has four clearance openings (not shown) for receiving threaded fasteners (not shown) which pass through the clearance openings and thread into threaded openings (not shown) in front section 201 A to join the two sections together. Each section has a semi circular shaped cut out 206 for receiving a race with ball bearings or a split sleeve bearing 207 and having cutouts 219 for engaging rails or projections (not shown) for engaging channels on work pieces that are to be joined by welding. The top surface of the front and back sections of the member 201 has four threaded openings (not shown) for receiving threaded fasteners (not shown) for securing a motor, such as a torque motor 308 to the member 201 when the front and back sections are joined together. The front surface and rear surface of member 201 can have four threaded openings for receiving threaded fasteners for securing pull members 210 to the crawler. The pull members are provided to receive a pull cable 201 P used to pull the crawler 200 B along the rails 701 on the work pieces at a predetermined speed during the welding process.
Prior to attaching the front 201 A and back 201 B sections of the member 201 together, and subsequent to inserting the split sleeve bearings 207 into respective cutouts 206 in the member, a Friction Stir Welding (FSW) tool 213 B is fitted in place in the split sleeves in the front section or back section and the two sections are then joined together to form the member 200 A. The FSW tool 213 B is configured to make one weld. The tool 213 can be a single member without any removable sections.
Continuing with FIG. 4 , the FSW tool 213 B has a single bearing surface 206 A adapted to rotatably engage a split sleeve bearing 207 or a race having ball bearings (not shown) in the front 201 A and back 201 B sections of member 201 . After the front and back sections of the member are joined together and encapsulate the replaceable FSW tool 213 B, a torque motor 308 is placed on the top surface 201 T of member 201 to engage a splined engagement pin 214 located at the end of the FSW tool 213 B, which projects above the top surface 201 T of member 201 . The torque motor 308 is then attached to the member 201 with threaded fasteners as described above.
In operation, when a weld is to be made, the bobbin 218 of the tool 213 B is located at the edge of two work pieces and in line with a weld joint that is to be made. A pull cable 201 P or other drive structure such as a screw drive (not shown) is coupled to the member 201 and is used to advance the crawler 200 B along the rails or channels on the work pieces 402 as the FSW tool 213 B is rotated and traverses along the weld seam.
FIG. 5 is a perspective view of a friction stir welding tool coupled to rails on work pieces where the members 530 located in the crawler 200 , in combination with the rails, urge the edges of the work pieces 600 A, 600 B and 601 A, 601 B) (as described above) toward each other to provide preloading of the work piece pairs and also provide guiding, alignment and torque compensation for the crawler. More specifically, in one embodiment, work pieces 600 , 601 can be of aluminum with enlarged edges 602 , 603 butted together with a predefined force by the crawler 200 as explained above. As the crawler is advanced by a driven take up reel 610 , or any other drive structure such as a screw drive (not shown) toward the left, the rotating FSW tool in the crawler 200 forms a weld joint 604 . It is to be noted that, as mentioned above, the members 201 , 202 , 203 of the crawler 200 are positioned both above and below the work pieces 600 , 601 and, as noted previously, the crawler is slidably clamped to work pieces 600 A, 600 B, 601 A, 601 B. Additionally, the crawler 200 , by urging the work pieces 600 A, 600 B and 601 A, 601 B toward each other, preloads the work pieces. The rails on the work pieces function as guides for the crawler 200 and also provides guiding, alignment and torque compensation for the crawler 200 .
In those instances where it is not possible to place a back up anvil on the back side of a weld being made, a bobbin-type tool may be used. Such tools include two shoulders and a pin located between them. The bobbin-type FSW tool 20 shown in FIG. 6 includes a pin 21 located between a pair of shoulders 22 which include work piece engaging surfaces 23 . The shoulders 22 can have a taper angle 24 and can be integral with pin 21 . To insure that the tool contacts and frictionally engages work pieces 111 , which may vary slightly in thickness, the work piece engaging surfaces 23 of the tool are tapered at an angle 24 shown in FIG. 6 .
The taper angle 24 enable work pieces having slightly different and/or somewhat variable thicknesses to be welded together and also ensures that the FSW tool is pressed against the work pieces with the force needed to both plasticize and confine the plasticized material in the weld area to produce smooth surfaces on the upper and lower surfaces of the weld.
FIG. 7 illustrates bobbin type tool 30 which can be used with the crawler here disclosed to weld one joint 113 of a pair of joints 113 and 114 to produce a tube from a pair of elongate members. The tube shown in FIG. 7 has a substantially square cross section, it being understood that the tube can have a cross section which is rectangular, circular, oval etc. In FIG. 7 , each elongate member 112 has a square C cross-sectional shape, and each elongate member corresponds to one half of the cross-section of the rectangular tube. It is here noted that the tool 30 is capable of welding only one joint at a time.
FIG. 8 shows a sectional view of a pin type tool 50 having an integral shank-pin with a shoulder 54 threaded onto the shank-pin to provide compression loading of the pin of a pin type tool. The tool 50 has a close fit 57 between the shank and the inside of shoulder 54 near the base of pin 52 , and has a positive stop 59 between the inside of shoulder 54 and the shank 53 . It is contemplated that this tool can be used with the crawler here disclosed which has only one member such as 201 which is located on the top surface of two work pieces and is pulled along the weld seam as the tool is rotating.
The tools referred to above can be used with a crawler here disclosed to make welds on many different types of structures, one such structure being parts for automobiles.
FIGS. 9-20 show various work piece configurations and types of welds that can be made with the FSW crawler here disclosed.
Referring to FIG. 9 , there is shown work pieces 700 , prior to being welded, which were extruded to have rails 701 at their edges. The rails 701 are substantially rectangular in shape and are partially consumed during the welding process. Note that the outboard edges 703 of the rails are intact after the weld is completed. FIG. 10 shows the plates after they have been welded together with the outboard edges 703 of the rails 701 still intact. FIG. 12 shows another type of weld that can be formed with work pieces of FIG. 11 having extruded rails 705 which are shorter in length. In the embodiment of FIG. 11 , the rectangular rails 705 of the work pieces which are shorter in length than the rails 701 are almost fully consumed during the welding process. In FIG. 12 , it can be seen that only the outboard ends 706 of the guide rails are not consumed during the welding process. FIG. 14 shows still another type of weld that can be formed with the work piece of FIG. 13 having extruded ends. The rails 708 of FIG. 13 are similar to the rails of FIG. 11 except the inboard ends 709 of the rails are undercut.
FIG. 16 shows another type of weld that can be formed with the work pieces 710 of FIG. 15 having channels 712 located near their ends. Note, in FIG. 16 the channels are completely consumed during the welding process. FIG. 18 shows another type of weld that can be formed with work pieces 713 of FIG. 17 having ends 715 entrapped with a snap guide 716 adapted to function as a guide rail for engagement by the crawler. The snap guide 716 and ends 715 are consumed during the welding process. FIG. 20 shows another type of weld that can be formed with the work pieces 718 of FIG. 19 having channels 719 located inboard from their ends 720 . With this embodiment, the channels 719 remain intact after the welding process.
While there has been described herein the principles of the invention, it is to be clearly understood to those skilled in the art that this description is made only by way of example and not as a limitation to the scope of the invention. Accordingly, it is intended to cover all modifications of the invention which fall within the true spirit and scope of the invention. | Portable friction stir welding apparatus having a crawler which supports a motor for rotating a Friction Stir Welding tool and is coupled to a drive mechanism for urging the crawler along a predefined weld path on work pieces. The crawler can comprise one member or a set of two or three physically separated members each rotatably coupled to the friction stir welding tool. The friction stir welding tool for making the weld is rotatably coupled to each member and restricts axial displacement of the physically separate members relative to each other. The members are adapted to engage rails on the work pieces which provide at least one of guiding, alignment, fixturing, torque compensation for the members as the friction stir welding tool is rotated and the crawler is moved along a joint. | 1 |
BACKGROUND OF THE INVENTION
In the design and manufacture of electronic devices and systems, it is now common practice to utilize electronic components which are directly mounted on printed circuit (PC) boards; the boards themselves are subsequently mounted in the system or device housing. This scheme tends to reduce the complexity and cost of assembly, and to simplify servicing procedures. Typical components of the kind referred to above are fabricated with a number of straight mounting leads or "legs" extending outwardly from the component. These legs are inserted into slots in the PC board so that the component is mounted essentially flat against the PC board. However, in numerous applications there has arisen the requirement that at least some components be mounted at an angle relative to the surface of the PC board. For example, in some light emitting diode (LED) optical displays, the LED chips must be mounted at an angle to the printed circuit board in order to provide appropriate viewing of the display. Typically, this is now done by mounting the LED chips on a separate circuit board which is tilted at an angle to the main circuit board. Harnesses or other flexible cable must then be used to electrically interconnect the two circuit boards, all of which entails undesirable assembly complexity and costs.
In order to provide such angular mounting some prior art dual inline integrated circuit (IC) sockets are presently manufactured in which the mounting leads each have an angular bend. Thus, when the leads are inserted into a PC board, the component will be tilted relative to the PC board at an angle determined by the angular bend in the leads. It is a disadvantage of such packages, however, that only one specific mounting angle is available for each package; thus, a large number of different packages, each having a different angular bend in the leads, must be manufactured and stocked if it is desired to mount components at differing angles.
SUMMARY OF THE INVENTION
In accordance with the illustrated preferred embodiments, the present invention provides a scheme for simply and easily mounting electronic components at any of a large number of angles relative to the plane of a printed circuit board or other mounting board. This is accomplished by configuring the mounting leads for the component as a sequence of concentric arcs of increasing radius. The leads are inserted into slots in a mounting board and rotated about the geometric center of the concentric arcs until the component is in a desired angular position. Soldering of the leads to the mounting board fixes the component at this desired position.
In accordance with certain of the preferred embodiments of the invention, one or more of the mounting leads may also include break-off tabs or other geometric irregularities to maintain the component at the desired mounting angle prior to soldering.
DESCRIPTION OF THE DRAWING
FIG. 1 shows an electronic component having mounting leads configured in accordance with aspects of the invention.
FIG. 2 shows a printed circuit card edgeconnector also having leads configured in accordance with aspects of the invention.
FIGS. 3A-3E illustrate mounting leads including different types of positioning elements.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 there is illustrated an electronic component 11 which for purposes of illustration is shown as one digit of an opto-electronic display such as a dual inline package (DIP) for a seven-segment LED display. The invention will also have applicability to other kinds of board-mounting components, such as IC sockets, switches and the like. Component 11 is mounted on a board 13, which may, for example, be a printed circuit (PC board, and is illustrated as being positioned at an angle θ with respect to the planar surface of PC board 13. Component 11 includes a number of mounting leads extending from each side of the package. The leads extending from the right side of the package are labeled 15A-15D, while several leads extending from the lefthand side are illustratively labeled 17A and 17B.
In accordance with the principles of the present invention, each of the leads 15A-15D is configured as an arc of a circle having a center at point 19 (the intersection of a center line 21 with one corner of package 11). For example lead 15C comprises an arc of a circle having a radius R as shown. The radii of each of the other leads are similarly determined by the distance of the lead from point 19. Leads 17A etc. on the left side of package 11 are configured in a similar manner. To mount component 11 on board 13, each lead is first inserted in a slot of board 13 (e.g. lead 15D is inserted in slot 16). Component 11 is then rotated about center line 21 until it is positioned at the desired angle θ. The leads are then soldered or attached in any conventional manner to permanently fix the mounting angle. From FIG. 1 it is evident that component 11 may be rotated through 90° from an angle substantially equal to zero to an angle substantially perpendicular to board 13. Thus, in addition to the inclined mounting positions possible, the component may also be conventionally flat mounted (θ=0) if desired.
In FIG. 1 the right side leads are configured as arcs having centers at point 19, chosen as one corner of component 11, and similarly for the left side leads. However, it is evident that the leads could also be configured as a sequence of concentric arcs about a different geometric center, e.g. somewhere below the component itself. The principles of the invention will still apply, but in this case the body of component 11 would "float" above the PC board after mounting. Other variations are also possible. For example, the leads may be configured as portions of a curve other than a circle, in which case the component would be positioned by a "rotational" movement determined by the particular curve of the leads.
FIG. 2 shows a printed circuit card edge-connector 23 including a number of leads, some of which are labeled 25A-25C (right side) and 27A (left side) which are formed as arcs centered about a center line 29 extending along one bottom edge of connector 23. In this case all of the leads running along the left side of the connector (27A etc.) have a first radius, while all of the leads running along the right side of the connector (25A, 25B etc.) have a second radius larger than the first. FIG. 2 therefore illustrates that the leads may be formed in the shape of arcs lying in the plane of the short dimension of the package to be mounted as well as in the plane of the long dimension as in FIG. 1. In accordance with this principle, the DIP package illustrated in FIG. 1 could alternatively have the arc of the leads lying in the short dimension of that package. This arrangement would allow tilted mounting of the package at varying angles from a center line extending along the long dimension of package 11. Additionally, tilted mounting at varying angles about other axes would also be possible if the mounting leads were suitably shaped.
In FIG. 3A there is again illustrated a package 31 including several arc-shaped mounting leads labeled 33A, 33B, and 33C. Lead 33C includes a number of small breakoff lugs 35 positioned at different angles around the periphery of the arc. To mount the component at a desired angle, the user simply breaks off all of the tabs below the particular tab corresponding to a desired mounting angle. Thus, when the leads are inserted into a mounting the component 31 will be freely rotatable until the first remaining lug encounters the surface of the PC board. The position of this lug will therefore determine the mounting angle. Although package 31 is illustrated here as including breakoff lugs on its outermost lead, it is evident that a similar purpose may also be affected with the lugs on some other lead.
FIG. 3B illustrates a mounting lead including a number of point-like extended portions 37 serving a similar function to lugs 35 of FIG. 3A. In this case, points 37 would be inserted in slightly oversized slots in a mounting board until a desired mounting angle was attained; the point corresponding to the desired angle will then rest on the surface of the PC board. In this embodiment, points 37 provide a ratchet-like effect, so that the component may be easily rotated backwards, withdrawing the leads from the slots in the board, in the event that the initial positioning happened to overshoot the desired angle.
In FIG. 3C an arc-like mounting lead 39 is shown including a number of "wiggles" 41 spaced at desired angles around the arc. If lead 39 is constructed to have a slight tension extending in an outwardly radial direction, then at the points determined by wiggles 41, lead 39 will tend to "latch" itself to a mounting board. Positioning at a desired angle is thereby facilitated.
In FIG. 3D there is shown yet another arc-like lead 43 including a number of substantially continuous wiggles 45. In this case lead 43 may be tensioned either inwardly or outwardly so that it will tend to latch on either the inward or outward radial side of any of the wiggles 45.
In FIG. 3E, still another arc-like lead 47 is formed as a many-sided polygon having typical sides 49 and 51. Thus, the component may be incrementally rotated through many angular positions corresponding to the various intersections or flats of the polygonal sides.
Those skilled in the art will understand from FIGS. 3A-3E that many other particular designs may be employed to facilitate positioning of the electrical component at desired angles with respect to a mounting board. | An electronic component is provided having mounting leads configured as concentric arcs centered about a desired axis of rotation. The leads may therefore be inserted into a mounting board, and the component rotated to a desired angle with respect to the surface of the mounting board. In some embodiments, one or more of the mounting leads is provided with tabs or other positioning elements to facilitate the positioning of the component at any of a number of selected angles relative to the mounting board. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for causing an explosion on one side of a bulkhead by initiating an explosion on the other side of the bulkhead and transmitting the explosive shock wave through the barrier. This is known in the aerospace industry as through-bulkhead initiation (TBI). In TBI technology it is desired to detonate an explosion on one side of a bulkhead and transmit that explosion through to other side of the bulkhead while maintaining the bulkhead structurally intact, that is without being cracked, ruptured or penetrated. Thus while an explosion is transmitted across the bulkhead, no gases, liquids or particles should be permitted to escape from one side to the other. On aerospace vehicles a TBI capability has many uses but finds its primary application in igniting the fuel contained within the fuel chamber of the rocket motor by initiating an explosion on the outside of the chamber.
Previous TBI devices use a variety of means to transmit the energy of an explosion across a bulkhead barrier. One device uses a pair of mating acceptor and donor charges to transmit the explosion. The donor charge on one side of the bulkhead is detonated by an explosive detonating cord and sends an explosive shock wave through the barrier setting off the acceptor charge on the other side. The acceptor charge in turn detonates an output explosive-charge. Two U.S. Pats. of this type are Allen, No. 3,238,876 and Webb, No. 3,209,692. While these devices have been shown to be operative, several problems have arisen in connection with their use. First, high, leak-promoting stress levels are experienced in the bulkhead area when the devices are actuated. Second, a number of small cracks in the barrier, caused by the passage of the explosive shock wave, have been observed. Third, the devices are complex and expensive to fabricate.
DEFINITIONS
For the purposes of accuracy and clarity the following definitions are provided for selected terms which are used in both the specification and claims of this application:
HERMETIC -- Made perfectly closed or airtight so that no matter, gas, liquid or solid, can enter or escape.
BARRIER -- That solid portion of the bulkhead or TBI device across and through which the explosive shock-wave is transmitted.
SHOCK WAVE -- A violent, moving disturbance which advances through a medium by transmission between particles of that medium.
BULKHEAD -- An upright partition separating two compartments.
SUMMARY OF THE INVENTION
Briefly, the invention comprises a through-bulkhead initiation device which has a barrier separating a first chamber for the receipt of an output explosive-charge from a second chamber for the receipt of an explosive detonating-cord. The second chamber is so dimensioned and configured as to be congruent with the output end-segment of the explosive detonating-cord, thereby bringing the end-segment of the cord in mating arrangement with one wall of the barrier, as a hand mates with a glove. When the detonating cord is ignited, it generates an explosive shock wave which is directly propagated across the barrier, without the necessity for an intervening booster or donor charge. When the shock wave crosses the barrier it causes the output explosive-charge which fills the chamber across the barrier to detonate. The explosion of the output explosive-charge is used to set off the rocket-fuel primer.
In one embodiment of the invention the output explosive-charge has two separate charges, one an acceptor charge and the other an output ignition-mix, without the need for a donor charge on the other side of the barrier.
In another embodiment of the invention, the acceptor charge is entirely eliminated, and due to a unique chamber configuration and use of a deflagrating output-charge, only the output-charge is detonated by the shock wave crossing the barrier. The further elimination of a component lowers extremely high leak-promoting stress levels experienced in the bulkhead area and minimizes the size and number of cracks in the barrier thereby enhancing the reliability of the device. Such elimination of a component also reduces the cost of the TBI device.
OBJECTS OF THE INVENTION
An object of the invention is to lower the extremely high leak-promoting stress levels experienced in the bulkhead due to the passage of the explosive shock wave across the barrier.
Another object of the invention is to minimize the number and size of cracks in the barrier due to the passage of the explosive shock wave across the barrier.
Another object of the invention is to eliminate the donor charge in a through-bulkhead initiation device thereby enhancing the reliability and reducing the cost of the device.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration, in cross-section, of one embodiment of the through-bulkhead initiator of the invention.
FIG. 2 is an illustration, in cross-section of a second embodiment of the through-bulkhead initiator of the invention.
FIG. 3 is a view along sectional line 3--3 of FIG. 2 illustrating the end portion of the chamber containing the output explosive-charge formed by four lower chambers protruding into the barrier.
FIG. 4 is a sectional view similar to that of FIG. 3 illustrating a modification of the embodiment of FIG. 2 in which the end portion of the chamber containing the output explosive-charge is formed by two lower chambers protruding into the barrier.
FIG. 5 is also a sectional view similar to that of FIG. 3 illustrating a modification of the embodiment of FIG. 2 in which the end portion of the chamber containing the output explosive is formed by an annular chamber protruding into the barrier.
In the drawings the same parts are designated by the same reference numerals while equivalent parts have prime designations.
DETAILED DESCRIPTION OF THE INVENTION
The through-bulkhead initiator of the invention includes a housing 10, a first chamber 12, a second chamber 14 and a barrier 16. First chamber 12 and second chamber 14 have end portions 18 and 20 respectively which define the first wall 19 and second wall 21 of barrier 16. The housing 10 is fabricated from a metallic structural material, such as a stainless-steel alloy. Some alloys which may be used are 304L ASTM low-carbon stainless-steel or 341 ASTM stainless-steel. The barrier 16 will thus form an integral, hermetic partition between first chamber 12 and second chamber 14. The housing 10 of the TBI is provided with a flange or flanges 22 for attachment to a bulkhead by means of conventional fasteners, such as screws or the like. An annular recess 24 in the housing 10 allows the housing to be sealed hermetically to the bulkhead, thereby preventing the passage of gases, fluids or particles between the two sides of the bulkhead. The first chamber 12 is provided with a mating end-closure 36 to contain output exlosive-charge 34. End closure 36 has recessed propellant-trap 40 capped at one end by metallic foil 42, a frangible, narrowed portion 44, and is sealed to housing 10 by means of a seal 46 and annular land 45. The end portion 18 of first chamber 12 defines the first wall 19 of barrier 16. First chamber 12 may have a variety of configurations and may contain varying compositions of explosive charges, as shown by the two embodiments of FIG. 1 and FIG. 2. The configuration of first chamber 12 and the composition of explosive charge 34 will be described hereinafter in greater detail. Directly across the barrier 16 from the first chamber 12 and coaxial with it lies the second chamber 14. Second chamber 14 is provided with threaded portion 26 and end portion 20 and is configured to accomodate explosive detonating cord 28 which is coupled to housing 10 by nut 30. Detonating cord 28 may be flexible, known as a flexible-confined detonating-cord, or rigid, known as a shielded-mild detonating cord, either of which is commercially available. End portion 20 of second chamber 14 which defines the second wall 21 of barrier 16 has dimensions and a configuration selected to be congruent with and to mate with the dimensions and configuration of end segment 32 of detonating cord 28. Thus, end segment 32 of detonating cord 28 will directly follow the contours and mate with the second wall 21 of the barrier 16, as a hand mates with a glove. The end segment of the cord, however, has a length which is slightly smaller than the length of end portion 20, allowing a slight clearance gap 23, or a proximate relationship between the end face of the cord and the second wall of the barrier. Gap 23 permits the shock wave to travel across it, impinge on the barrier wall 21, be transmitted through barrier 16 to acceptor charge 50 and ignite output explosive-mix 48 while concurrently preventing barrier rupture caused by a backup force or backlash pressure returning across the barrier when the output explosive-charge detonates.
FIGS. 1 and 2 of the drawings disclose two embodiments of the invention which differ only in the configuration and dimensions of the first chamber and first wall of the barrier, and in the composition of the output explosive-charge.
In FIG. 1, the output explosive-charge 34 has two parts, an output explosive-mix 48 and an acceptor charge 50. The output explosive-mix 48 may be any of a number of handy and well recognized loose-grained explosive materials, and should be insensitive to light shocks due to handling. For example, a mixture of magnesium, potassium perchlorate, cupric oxide and and aluminum may be used without a binder or in a small amount of binder. (It is preferable not to use a binder at all since a binder acts to inhibit the initiation transfer from the explosive input 32 to the deflagrating mixture 48.) The acceptor charge 50 is an explosive such as a crystalline high explosive which is sufficiently sensitive to detonate in response to a shock wave transmitted across the barrier 16. Examples of such explosives are pentaerythritol tetranitrate (PETN), cyclonite (RDX), hexanitro stilbene I, II (HNSI, II) and trinitroglycerine (TNT). Acceptor charge 50 fills the entire end portion of first chamber 12 so that the acceptor charge is directly in contact with the barrier 16, and coaxial with and directly across the barrier from the end portion of chamber 14. The remainder of first chamber 12 is filled with the output explosive mix, as described above.
In the operation of the embodiment of FIG. 1 when it is used to ignite the fuel-primer of a rocket motor, a remote command ignites the leading edge (not shown) of detonating cord 28. The detonating cord transmits the explosion through to the end segment 32 of the cord. The explosion at the tip of end segment 32 inside second chamber 14 produces an explosive shock-wave inside the chamber which travels across gap 23 and impinges on the second wall 21 of the barrier 16. The shock wave of the explosion is propagated longitudinally through barrier 16, without physically rupturing the barrier. When the shock wave crosses the barrier and reaches first wall 19 of the barrier, acceptor charge 50 will detonate in response to the shock wave, and will then detonate output explosive-mix 48. When mix 48 ignites, the pressure of the gaseous reaction products of the explosion ruptures metallic foil 42, forces the products through propellant trap 40, and ruptures the narrow, frangible portion 44 of end closure 36. This pressure carries along the metallic components of mix 48 which have been highly heated by the explosion, but leaves unheated propellant particles behind in propellant trap 40. The pressure then shoots both gaseous reaction products and highly heated metallic components out through the ruptured portion 44 of the end closure, igniting the rocket-motor fuel-primer (not shown).
The thickness of barrier 16 is of great importance in assuring a successful TBI. A compromise between a thick barrier which is less likely to crack or rupture under pressure of the explosive shock wave, and a thin barrier which will insure initiation of the acceptor charge must be made. Tests varying only barrier thickness were performed to obtain statistical data useful in determining optimal barrier thickness. Using this data as a guide, combined with empirical engineering data and safety factors, a barrier thickness of 0.100 of an inch has been established as the optimum, although barrier thicknesses may range from 0.050 to 0.140 of an inch.
FIGS. 2 and 3 depict an additional embodiment of the invention which eliminates the acceptor charge 50 of the embodiment of FIG. 1. FIGS. 2 shows a first chamber 12 with output explosive-charge 34 consisting only of uniform output explosive-mix 48 and absent any additional acceptor charge. To detonate without benefit of an acceptor charge, output explosive-mix must be sufficiently sensitive to the explosive shock produced by the detonating cord only. A sensitive deflagrating explosive is therefore required, for example a mixture of magnesium, potassium perchlorate, cupric oxide and aluminum preferably without a binder or in a small amount of binder. Additionally the deflagrating explosive must be placed in relation to the detonating cord so as to efficiently absorb the full effects of the shock wave as it crosses the barrier 16. As seen in FIG. 2 first chamber 12 has an end portion 18 1 which communicates with chamber 12 and which protrudes into barrier 16 so that end portion 18 1 overlaps the end portion 20 of second chamber 14 and the end segment 32 of cylindrical detonating-cord 28. Additionally, end portion 18 1 extends parallel to and along an appreciable portion of the length of end portion 20 and end segment 32. This protruding configuration allows the output explosive-mix 48 in chamber 12 to receive the explosive shock wave transmitted both longitudinally from the flat end face of the detonating cord and radially from the circular peripheral face of the cord. The end portion 18 1 of first chamber 12 may be formed in a number of ways with a variety of cross-sectional shapes. In the embodiment of FIG. 3, for example, end portion 18 1 is formed by boring four holes in the housing, all located substantially 90° apart on the periphery of an imaginary circle coaxial with second chamber 14. FIGS. 4 and 5 show two other possible transverse cross-sectional shapes for end portion 18 1 of chamber 14. In FIG. 4, end portion 18 11 is formed by boring two holes in the housing, each located on an imaginary circle coaxial with second chamber 14 and space substantially 180° apart. FIG. 5 shows an additional modification in which end portion 18 111 has an annular transverse cross-section and is coaxial with second chamber 14. In each of these modifications, end portions 18 11 and 18 111 protrude into the barrier and extend parallel to and along an appreciable portion of the length of end portion 20 of first chamber 12 and end segment 32 of explosive detonating-cord 28. The operation of the embodiment of FIG. 2 and of the modifications shown in FIG. 4 and FIG. 5 of the TBI is similar to the operation described above for the embodiment of FIG. 1. When detonating-cord 28 is remotely ignited, the explosion is transmitted to end segment 32, causing an explosion in the end portion 20 of chamber 14. The explosion generates a shock wave which travels across gap 23 and then impinges on the second wall 21 of chamber 14 across barrier 16 where it causes detonation of the output explosive-charge 34. The shock wave of the explosion, while traveling longitudinally from the end face of detonating cord 28 through barrier 16, also travels radially from the circular periphery of the side face of end segment 32 of the cord across the barrier to end portions 18 1 to 18 111 of first chamber 12. When the shock reaches end portions 18 1 to 18 111 it has a crushing effect on these portions of the chamber, igniting the deflagrating output explosive-mix 48 contained therein. The explosion of the output explosive-mix then ruptures foil 42, frangible portion 44 of end closure 38 and ignites the rocket-motor fuel-primer (not shown).
Modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A device which transmits an explosion across a bulkhead through a solid hetic barrier while maintaining the barrier integrally intact and without perforating or rupturing it. The barrier separates a first chamber which receives an output explosive-charge from a second chamber which receives a detonating cord. When the detonating cord is ignited it causes an explosive shock wave to cross the barrier and detonate the output explosive charge. The end of the second chamber has a configuration and dimensions congruent with the output end of the detonating cord so that the explosive shock wave directly crosses the barrier without the need for an explosive charge intermediate the cord and barrier wall. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This patent application is a continuation-in-part of U.S. patent application Ser. No. 09/089,372 that was filed on Jun. 3, 1998, now U.S. Pat. No. 6,139,810, and is incorporated by reference in its entirety herein.
FIELD OF THE INVENTION
The invention relates to a process for producing a product gas, such as syngas or an unsaturated hydrocarbon, in a reactor through an endothermic steam reforming reaction. The heat energy to sustain the endothermic reaction is generated by combusting a fuel with oxygen obtained from either the permeate or the retentate portion of an oxygen-containing gas following gas separation by contact with an oxygen-selective ion transport membrane.
BACKGROUND OF THE INVENTION
Natural gas and methane, a major constituent of natural gas, are difficult to economically transport and are not easily converted into liquid fuels or chemicals, such as gasoline, methanol, formaldehyde and olefins, that are more readily contained and transported. To facilitate transport, methane is typically converted to synthesis gas (syngas) which is an intermediate in the conversion of methane to liquid fuels, methanol or other chemicals. Syngas is a mixture of hydrogen and carbon monoxide with an H 2 /CO molar ratio of from about 0.6 to about 6.
One chemical reaction effective to convert methane to syngas is steam reforming. Methane is reacted with steam and endothermically converted to a mixture of hydrogen and carbon monoxide. The heat energy to sustain the endothermic reaction is generated by the external combustion of fuel. The steam reforming reaction is of the form:
CH 4 +H 2 O→3H 2 +CO
and produces syngas at an H 2 /CO molar ratio of 3.
A second chemical reaction effective to convert methane to syngas is partial oxidation. Methane is reacted with oxygen in an exothermic reaction of the form:
CH 4 +½O 2 →2H 2 +CO. (2)
and produces syngas at an H 2 /CO molar ratio of 2.
U.S. Pat. No. 5,306,411 to Mazanec, et al., that is incorporated by reference in its entirety herein, discloses the production of syngas by combined partial oxidation and steam reforming. The syngas is then converted to liquids by the Fischer-Tropsch process or can be converted to methanol by commercial processes.
In accordance with the Mazanec et al. patent, oxygen for an anode side reaction is obtained by contacting an oxygen-containing gas, preferably air, with the cathode side of a mixed conductor oxygen-selective ion transport membrane element and permeating oxygen by ion transport to the anode side of the mixed conductor. The membrane element has infinite oxygen selectivity. “Oxygen selectivity” is intended to convey that oxygen ions are preferentially transported across the membrane over other elements, and ions thereof. The membrane element is made from an inorganic oxide, typified by calcium- or yttrium-stabilized zirconia or analogous oxides having a fluorite or perovskite structure.
At elevated temperatures, generally in excess of 400° C., the membrane element contains mobile oxygen ion vacancies that provide conduction sites for the selective transport of oxygen ions through the membrane elements. The transport through the membrane elements is driven by the ratio of partial pressure of oxygen (P o2 ) across the membrane: O−ions flow from the side with high P o2 to the side with low P o2 .
Ionization of o 2 to O − takes place at the cathode side of the membrane element and the ions are then transported across the membrane element. The O − ions then either combine to form oxygen molecules or react with a fuel, in either instance releasing e − electrons. Membrane elements that exhibit only ionic conductivity include external electrodes located on the surfaces of the membrane element. The electron current is returned to the cathode by an external circuit. Membrane elements having both ionic conductivity and electron conductivity transport electrons back to the cathode side internally, thus completing a circuit and obviating the need for external electrodes.
Commonly owned U.S. patent application Ser. No. 09/089,372 discloses the production of a product gas, typified by syngas, utilizing an oxygen selective ion transport membrane element to provide oxygen for combined endothermic and exothermic reactions where the overall reaction is exothermic or energy neutral. At least one of the endothermic reaction, the exothermic reaction and the internal heat transfer within the reactor is controlled to maintain the oxygen selective ion transport membrane within prescribed thermal limits since the membrane material will degrade at temperatures above about 1100° C.
The ion transport membrane enables the local transfer of oxygen into the reaction passage to sustain the partial oxidation reaction without contaminating the reaction products with nitrogen. The balance between the reforming and partial oxidation reactions will depend on relative reaction kinetics which are influenced by the process feed composition, catalyst activity and the amount of oxygen transferred. The reactions typically are conducted at a temperature from 400° C. to 1200° C. and preferably between 800° C. and 1050° C. Since the partial oxidation reaction is exothermic and the reforming reaction endothermic, the balance between the two will determine whether the overall process is exothermic or endothermic. Depending on the operating pressure the process is energy neutral at H 2 /CO molar ratios in the range of 2.3 to 2.5, produces excess energy below that range and requires additional heat above the range.
In accordance with the Ser. No. 09/089,372 patent application, the heat generated by the exothermic partial oxidation reaction is sufficient to satisfy the requirements of the endothermic reaction and, preferably, generates a heat surplus to compensate for thermal losses.
When the exothermic reaction is partial oxidation of methane, the reaction generates two moles of hydrogen for every mole of carbon monoxide produced. When the endothermic reaction is steam reforming, the reaction generates three moles of hydrogen for every mole of carbon monoxide produced.
The process and reactor designs disclosed in the Ser. No. 09/089,372 application are particularly suited for generating syngas with H 2 /CO molar ratios in the range of 2.3 to 2.5, dependent on reactor pressure.
For certain chemical processes, it is desirable to have syngas with an H 2 /CO molar ratio greater than about 2.3.
To shift the H 2 /CO ratio to greater than 2.3 to 2.5, it is possible to generate additional heat by driving the partial oxidation reaction towards more complete oxidation. This approach also generates more H 2 O and more CO 2 that must be removed from the product gas at some expense. In addition, the additional fuel burned during oxidation is high grade, and therefore expensive, natural gas.
A second approach is to provide externally generated heat to the reactor. This approach is also less than satisfactory because of the associated cost.
U.S. Pat. Nos. 5,565,009 and 5,567,398 to Ruhl, et al., that are incorporated by reference in their entireties herein, disclose manufacturing syngas by steam reforming of methane in a catalyst bed located on the shell side of a tube and shell reactor. The heat for sustaining the reforming reaction is provided by combustion of fuel within tubes where the fuel and oxygen supply (air) are separately heated and only combined after they reach their auto-ignition temperature. The oxygen is provided by air and the nitrogen contained within that air is heated during combustion to form a number of detrimental NOx compounds that can only be removed from the combustion products gas with difficulty.
U.S. patent application Ser. No. 08/848,204 entitled “Solid Electrolyte Ion Conductor Reactor Design” by Gottzmann, et al., that was filed on Apr. 29, 1997, now U.S. Pat. No. 5,820,655 and it is incorporated by reference in its entirety herein, discloses using the heat generated by an exothermic oxidation reaction to heat an oxygen-containing feed gas prior to delivery of that feed gas to the cathode side of an oxygen-selective ion transport membrane element. The Ser. No. 08/848,204 application also discloses the use of a thermally conductive shroud tube surrounding the membrane elements to enhance the transfer of heat while maintaining isolation of gases.
While the aforementioned disclosures recite processes and reactors for the production of syngas utilizing an oxygen-selective ion transport membrane element and utilizing the heat generated by an exothermic partial oxidation reaction to drive an endothermic steam reforming reaction, they are generally limited to the production of syngas with H 2 /CO molar ratios of from 2.3 to 2.5, depending on reaction side pressure, and where the heat released by the exothermic partial oxidation reaction is equal to or greater than the heat required for the endothermic reforming reaction. Higher molar ratios are obtainable by providing additional heat to drive the steam reforming reaction, but this approach requires the addition of externally generated heat, at a significant expense, and is typically associated with the formation of undesirable NOx compounds.
There remains, therefore, a need for a method to generate syngas having H 2 /CO molar ratios higher than 2.3 to 2.5 that does not have the limitations of the prior art.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to provide a process for the production of syngas having H 2 /CO molar ratios the generation of which requires more heat than is available from the balance of exothermic and endothermic reactions.
It is another object of the invention to provide processes and reactor designs where all or at least a portion of a heat generating oxidation reaction excludes nitrogen from the reaction environment by the use of ion transport membranes that are exclusively selective for oxygen, thereby minimizing NOx formation.
Yet another object of the invention is to provide a combustion reaction in a syngas reactor at a location effective for transfer of heat to an adjacent endothermic reaction. The oxygen for the combustion reaction is provided by contacting an oxygen containing gas, typically air, with an oxygen-selective ion transport membrane and then reacting either a permeate portion of the oxygen or a retentate portion of the oxygen with a fuel to generate heat for the endothermic reaction.
Still another object of the invention is to utilize a fuel having a relatively low heating value for the combustion reaction. Typically, the heating value of this fuel is less than 500 BTU/FT 3 , considerably less than that of natural gas that typically has a heating value in excess of 900 BTU/FT 3 . This enables the use of inexpensive flare gases (the waste product burned in a flare at refineries and other chemical plants) or pressure swing adsorption (PSA) tail gases. Utilization of these low heat value fuels, that were previously viewed as waste streams, provides a significant cost advantage.
A still further object of the invention is to include, if required by the desired H 2 /CO ratio, a partial oxidation reaction that provides portions of the syngas product and of the heat to enable the endothermic partial oxidation reaction to proceed.
Yet another object of the invention is to provide syngas reactor designs effective to achieve the process objectives stated above.
SUMMARY OF THE INVENTION
In one aspect, this invention comprises a process for providing heat to an endothermic reaction inside a reaction passage. The process includes the step of:
(1) separating the endothermic reaction from a combustion site with a nitrogen impervious barrier;
(2) flowing an oxygen containing gas through an air passage along a cathode side of an oxygen-selective ion transport membrane element at a temperature and at an oxygen partial pressure effective to separate oxygen contained within the oxygen-containing gas into a permeate portion that is transferred through the oxygen-selective ion transport membrane element to an anode side and a retentate portion that is retained on the cathode side;
(3) combusting a fuel with at least one of the permeate portion and the retentate portion at the combustion site to form a heat of combustion; and
(4) transferring the heat of combustion to the endothermic reaction.
In a preferred embodiment of this aspect, the oxygen-selective ion transport membrane element separates the reaction passage from the air passage. The cathode side of the oxygen selective ion transport membrane element is adjacent to the air passage and the anode side of the membrane is adjacent to the reaction passage. A fuel is injected into the air passage to react with oxygen contained in the retentate and thereby provide the energy required by the process. In another preferred embodiment of this aspect, the reaction passage is separated from a combustion passage by the oxygen-selective ion transport membrane element with the cathode side of the oxygen-selective ion transport membrane being adjacent to the combustion passage and the anode side being adjacent to the reaction passage. A second oxygen-selective ion transport membrane element separates the combustion passage from the air passage. This second oxygen-selective ion transport membrane element is effective for separating the oxygen containing gas into a second oxygen permeate portion that is transferred through the second oxygen-selective ion transport membrane element to a second anode side that is adjacent to the combustion passage and a second retentate portion that is retained on the second cathode side.
A third preferred embodiment is suitable for producing syngas at H 2 /CO ratios equal to or greater than 3. In this embodiment, the wall separating the reaction passage from the air passage is an impervious element permitting neither oxygen nor nitrogen to enter the reaction space thereby permitting only the endothermic reforming reaction to take place. The energy for the process is provided by the combustion of fuel with oxygen permeating from the oxygen containing gas on the cathode to the anode of the second ion transport membrane.
In all of the above preferred embodiments, the fuel utilized for combustion preferably has a heating value of less than 500 BTU/FT 3 whereby fuel sources typically viewed as waste streams may be utilized. Such fuel sources include flare gases and PSA tail gases.
In a second aspect, the invention comprises a reactor which employs an oxygen transport membrane to supply oxygen to the catalyst laden process side to support a partial oxidation reaction which will supply part of the energy required to sustain the endothermic reforming reaction but which also has provisions for the combustion of fuel in the air passage to generate additional heat. The reactor has a hollow shell that defines an enclosure. A fuel tube extends into the enclosure. This fuel tube has first and second opposing ends. A tubular first oxygen-selective ion transport membrane tube having a tube side and a shell side circumscribes at least a portion of the fuel tube. The shell side of the first oxygen-selective ion transport membrane defines a nitrogen impervious zone within the hollow shell. This first oxygen-selective ion transport membrane element further has a cathode side that is adjacent to the fuel tube and an opposing anode side. A reforming enhancing catalyst is disposed exterior to the first anode side on the shell side. A first fuel source is connected to a first end of the fuel tube and an oxygen-containing gas source is connected to a first end of the tubular first oxygen-selective ion transport membrane element. A process gas source is connected to the shell side of the first oxygen-selective ion transport membrane element.
A preferred embodiment of the second aspect enables the combustion reaction to occur on the anode of a second oxygen transport membrane in the absence of atmospheric nitrogen. In this embodiment, an endothermic reaction isolating tube, which can be the first oxygen ion transport membrane or a nonpermeable barrier, circumscribes at least a portion of a second tubular oxygen-selective ion transport membrane element to define an annulus. This annulus is located between an inside surface of the endothermic reaction isolating tube, or cathode of the first ion transport membrane element, and an outside surface of the second tubular oxygen-selective ion transport membrane element. In most preferred embodiments, this annulus has a width of less than 5 millimeters to enhance convective heat transfer coefficients. If a nonpermeable barrier tube is used it can be made of a metallic or ceramic material. In this embodiment, air fed to the annulus transfers oxygen to the combustion zone inside the second ion transport membrane and optionally also to the process side outside the first ion transport membrane tube to support a partial oxidation reaction. In another preferred embodiment of the second aspect, the second end of the fuel tube is sealed and the fuel tube has a plurality of annular orifices that are effective to deliver the fuel to the first anode side at selected locations.
In a third aspect of the invention, the reforming reaction takes place inside an inner tube which can be an ion transport membrane or a nonpermeable isolating tube, and the combustion reaction occurs shell side or outside a second ion transport membrane, where air for the supply of oxygen flows in the annulus between the two tubes. A reactor is provided that has a hollow shell defining an enclosure. Inside the shell, sets of two concentric ion transport membrane tubes are provided. The annulus defined by the outer diameter of the inner tube and the inside diameter of the outer tube serves as an air passage. Reforming catalyst is disposed within the inner ion transport membrane to define a zone for the reforming reaction.
The tube side of the inner oxygen-selective ion transport membrane element defines a nitrogen impervious zone as does the space between the outer ion transport membrane tube and the shell. A supply of a mixture primarily consisting of methane and steam is connected to a first end of the inner tube, a fuel gas to an inlet on the shell side outside the outer tube and an air supply to a first end of the annulus between the tubes. The second end of the inner tube is connected to product withdrawal means while the second end of the annulus and a shell outlet are connected to waste discharge means. optionally, the discharges from the annulus and the shell side can be combined within the shell space by terminating the outer tube within the shell space.
The tubular oxygen-selective ion transport membrane elements further have an anode side adjacent to the fuel side and process gas side and an opposing cathode side facing the annulus or air passage to enable the transport of oxygen for a partial oxidation reaction on the anode of the inner tube and a combustion reaction on the anode of the outer tube. optionally for generating syngas with high H 2 /CO ratios the inner tube can be a nonpermeable barrier.
In yet another preferred embodiment, separate ion transport membrane tubes for the reforming-partial oxidation reaction and for the combustion reaction are disposed within a common shell and isolate the reforming and combustion zones from atmospheric nitrogen. The tubes are attached to opposing tube sheets on the common shell. A first capped ion transport membrane tube circumscribes at least partially a process gas supply or withdrawal tube and has a reforming catalyst disposed in the annulus between the ion transport membrane tube and the supply or withdrawal tube. A combined partial oxidation and reforming reaction takes place in this tube. The outer or cathode surface of the tube faces the shell side. A second ion transport membrane tube is open at one end and closed at the other end and circumscribes a closed end fuel supply tube featuring fuel inlet orifices at desired locations. The cathode of the second ion transport membranes faces the shell side. A combustion reaction takes place inside this second ion transport membrane tube. The shell side is connected to an air supply to provide the oxygen for the partial oxidation and the combustion reactions by ion transport across the respective membrane surfaces. Multiple baffles provide for cross counterflow of air through the shell. Adequate heat transfer from the combustion reaction tube to the reforming tube is provided by radiation and air convection. As in previous embodiments, a nonpermeable barrier tube can replace the first ion transport membrane tube at high H 2 /CO ratios.
In any one of the aspects of the invention described above, the tubular oxygen-selective ion transport membrane elements are preferably formed from a mixed conductor metal oxide that is effective for the transport of elemental oxygen at elevated temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages will occur to those skilled in the art from the following description of preferred embodiments and accompanying drawings in which:
FIG. 1 illustrates in cross-sectional representation a first method for internally generating heat to sustain an endothermic reaction.
FIG. 2 illustrates in cross-sectional representation an apparatus to deliver fuel to preferred combustion sites.
FIGS. 3-5 illustrate in cross-sectional representation alternative methods for internally generating heat to sustain an endothermic reaction.
FIGS. 6-8 illustrate reactor designs effective to generate syngas according to the methods of the invention.
FIG. 9 illustrates an orientation pattern for a plurality of heat generating combustion tubes and heat requiring reformer tubes for use in the reactors of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates in cross-sectional representation a first process for providing heat to an endothermic reaction in accordance with the invention. The endothermic reaction occurs substantially within reaction passage 10 . A preferred endothermic reaction is steam reformation. Process gas 12 , a mixture of gases that contain the constituents required for steam reformation flow through the reaction passage 10 . For the production of syngas, process gas 12 includes methane (or other light hydrocarbons) and steam. Process gas 12 may also contain other reactive constituents such as carbon dioxide as well as inert gases.
To enhance the formation of product gas 14 , that is preferably syngas with a hydrogen to carbon monoxide molar ratio exceeding about 2.3 to 2.5, a catalyst bed 16 fills at least a portion of the reaction passage 10 . The catalyst may consist of beads or alternatively be disposed on a monolithic substrate or contained in a porous layer attached to a wall of the passage. The catalyst may be uniformly dispersed throughout the reaction passage 10 and have uniform activity or gradationally dispersed and have graded activity to enhance the steam reforming reaction at selected portions of the reaction passage. The catalyst is selected to be effective in enhancing steam reforming of methane to syngas. One such catalyst is nickel, that may be supported on an alumina substrate As a practical constraint, the reactors of the invention include at least one oxygen-selective ion transport membrane element 18 . The ion transport membrane element 18 is preferably a mixed conductor metal oxide having an anode on the side facing reaction passage 10 and a cathode on the opposing side. Air flowing in air passage 26 provides oxygen that is transferred by ion transport to the anode side where a partial oxidation reaction takes place.
The heat required to sustain the endothermic reaction is generated in part by a partial oxidation reaction on the anode of the ion transport membrane 18 and in part by the combustion of fuel at combustion site 20 . To minimize contamination of the product gas 14 with nitrogen, the combustion site 20 is isolated from the endothermic reaction by a nitrogen impervious barrier. In the embodiment illustrated in FIG. 1, the oxygen-selective ion transport membrane element 18 functions as the nitrogen impervious barrier.
The oxygen-selective ion transport membrane element 18 may be formed as either a dense wall solid oxide mixed or dual phase conductor or, preferably, as a thin film mixed solid oxide or dual phase conductor that is supported on a porous substrate.
Preferably, the membrane film only spans that portion of the reaction passage 10 filled with catalyst 16 with the remaining length of the membrane coated with a metallic or ceramic, gas impervious, seal coat such as nickel or ceria.
When in the form of a monolithic structure, the oxygen-selective ion transport membrane 18 has a nominal thickness of under 5,000 microns and is preferably less than 1,000 microns thick. When a composite, the membrane element typically has a thickness of less than 100 microns and is supported on a porous substrate that is preferably made from a low cost ceramic or nickel-containing, metal alloy. Suitable metal alloys include Inconel 200 and Haynes alloy 230. The support structure may also be formed from a high strength ceramic material such as alumina, ceria or a mixture thereof.
Typically, an intermediate porous layer is disposed between the oxygen-selective ion transport membrane film and the porous substrate to bridge chemical and mechanical incompatibility between the substrate and the membrane. Use of a dense mixed conducting layer on an intermediate porous transition layer over a porous substrate is disclosed, for example, in U.S. Pat. No. 5,240,480 by Thorogood, et al.
The membrane element has the ability to transport oxygen ions and electrons at the prevailing oxygen partial pressure in the temperature range from about 450° C. to about 1200° C. when a chemical potential difference is maintained across the ion transport membrane surface caused by maintaining a positive ratio of oxygen partial pressures across the ion transport membrane. This positive ratio is preferably achieved by reacting transported oxygen with an oxygen consuming process gas. The oxygen ion conductivity is typically in the range of between 0.01 and 100S/CM where S(“Siemens”) is reciprocal ohms (1/Ω).
Suitable materials for the ion transport membrane include mixed conductive perovskites and dual phase metal-metal oxide combinations as disclosed in U.S. Pat. Nos. 5,702,959 (Mazanec, et al.), U.S. Pat. No. 5,712,220 (Carolan, et al.) and U.S. Pat. No. 5,733,435 (Prasad, et al.), all of which are incorporated herein by reference.
Since the reactive environment on the anode side of the oxygen-selective ion transport membrane element typically creates very low partial oxygen pressures, the chromium containing perovskites listed in the cited patents may be preferred materials since these tend to be stable in the low partial oxygen pressure environment. The chromium containing perovskites are not typically decomposed at very low partial oxygen pressures.
Optionally, a thin porous catalyst layer, possibly made from the same perovskite material, may be added to one or both sides of the oxygen transport membrane element to enhance oxygen surface exchange and the chemical reactions on the surfaces. Alternatively, the surface layers of the oxygen selective ion transport membrane element may be doped, for example, with cobalt, to enhance surface exchange kinetics. The oxygen selective ion transport membrane element 18 has a cathode side 22 and an anode side 24 . The oxygen-selective ion transport membrane element 18 may be formed in any desired shape, such as tubes or plates.
The cathode side 22 contacts the air passage 26 . An oxygen-containing gas 28 flows through the air passage 26 contacting cathode side 22 . The oxygen partial pressures in the air passage 26 and the reaction passage 10 are effective to cause a portion of the oxygen contained within the air 28 to be transported 30 from the cathode side 22 to the anode side 24 . Preferably, the oxygen partial pressure on the cathode side 22 is at least a factor of 1,000 greater than the oxygen partial pressure on the anode side 24 . More preferably, the oxygen partial pressure differential is on the order of between 1010 and 1015. For example, the oxygen partial pressure on the cathode side may be on the order of 0.1 to 10 atmospheres and on the anode side on the order of 10-14 atmosphere.
A fuel 32 is injected into the air passage 26 and is combusted at combustion site 20 generating heat that is conducted through the oxygen-selective ion transport membrane element to the endothermic reaction. While the fuel 32 may be a high heat value fuel such as natural gas or methane, low heat value fuels provide sufficient heat to sustain the endothermic reaction. Low heat value fuels, typically having a heat value of between 150 and 500 BTU/FT 3 include PSA tail gases and refinery flare gases. Since these low heat value gases are typically viewed as waste product streams, the fuel 32 can be provided at a significantly low cost.
The incoming oxygen-containing gas 28 , typically air, contains about 21%, by volume, of oxygen at sea level. On contacting the oxygen-selective ion transport membrane element 18 at an effective temperature and oxygen partial pressure, a portion of the oxygen, the permeate portion, is transported through the oxygen-selective ion transport membrane element and a second portion of the oxygen contained in the air reacts with fuel 32 . The remainder of the stream, the retentate, containing primarily nitrogen and some residual oxygen, is discharged as oxygen-depleted gas 34 . This oxygen-depleted gas typically contains less than 6%, by volume, of oxygen, but effectively supports combustion. Therefore, it is not necessary to provide a separate oxygen source to support combustion at the combustion site 20 .
Rather than mixing the fuel 32 with air 28 and risking early and non-uniform combustion, it is preferred to inject the fuel 32 uniformly along the length of the air passage 26 or, in the alternative, in a predetermined fashion to generate heat as required by local energy balances. With reference to FIG. 2, a fuel tube 36 formed from a material having a sufficiently high temperature to withstand the combustion temperature, such as stainless steel or a ceramic, is inserted into the air passage 26 . The fuel tube 36 has a first end 38 that is typically open and an opposing second end 40 that is typically closed. Multiple orifices 42 extend through the fuel tube. The fuel 32 enters at the first end 38 and flows through fuel tube 36 exiting through the multiple orifices 42 .
The multiple orifices 42 may be uniformly spaced along the length of the fuel tube 36 . Preferably, the multiple orifices are disposed in a predetermined fashion to generate heat were most required by local energy balances. Typically, as illustrated in FIG. 2, the greater energy deficit occurs at the end of reaction passage 10 where the process gases 12 are introduced.
A typical syngas producing plant utilizing PSA tail gas as the fuel 32 and a mixture of methane and steam as a process gas will produce sufficient energy to generate syngas with an H 2 /CO molar ratio of about 2.7.
FIG. 3 illustrates an alternative process flow for the production of syngas at a H 2 /CO molar ratio of 3 or higher. The energy to support the reforming reaction is provided by combustion of the fuel 32 in a combustion passage 44 with oxygen for the combustion supplied by ion transport through ion transport membrane 24 . Combustion passage 44 is disposed between the reaction passage 10 and the air passage 26 . In this embodiment, the nitrogen impervious barrier 46 between the combustion passage and the reforming passage is formed from a thermally conductive, gas impervious, material such as a metallic or ceramic tube or plate.
The oxygen selective ion transport membrane element 18 is disposed with anode side 24 forming a wall of the combustion passage 44 and cathode side 22 forming a wall of air passage 26 . Oxygen containing gas 28 , typically air, flows through the air passage 26 contacting cathode side 22 such that a permeate portion of the oxygen contained within the air 28 is transported 30 through the oxygen-selective ion transport membrane element 18 to support combustion at site 20 within combustion passage 44 .
The fuel 32 may be a fuel with a low heating value. Unlike in the embodiment illustrated in FIG. 1, the combustion environment does not contain any nitrogen since only oxygen is transported 30 through the oxygen selective ion membrane element. Therefore, combustion products 48 exiting the combustion passage 44 are substantially free of NOx compounds.
The use of an ion transport combustion membrane has the advantage that the reaction is distributed along the length of the passage by local oxygen transport and is relatively independent of local fuel/oxygen ratios in the interior of the combustion passage. Therefore wall temperatures are easier to control within a relatively narrow range. The temperature of the oxygen selective ion transport membrane element is controlled to stay within the operating range of the selected ion transport material, typically from 700° C. to 1100° and, preferably between 800° C. and 1000° by control of the mass flow rate of the air 28 and fuel 32 , local oxygen flux, the local reaction kinetics in passage 10 , by catalyst activity and fluid composition, and appropriate heat transfer from the membrane surface to the reforming passage by radiation and convection. The heat capacity of the retentate stream can act as a moderator to limit local temperature excursions. Use of distributed fuel injection as in FIG. 2 can lend an additional measure of control.
FIG. 4 illustrates yet another process in accordance with the invention. Air passage 26 is disposed between combustion passage 44 and reaction passage 10 . The first oxygen-selective ion transport membrane element 18 separates the air passage 26 from the combustion passage 44 with the cathode side 22 adjacent to the air passage 26 and the anode side 24 adjacent to the combustion passage 44 .
A second oxygen selective ion transport membrane element 50 separates the combustion passage 44 from the reaction passage 10 with the second cathode side 52 adjacent to combustion passage 44 and the second anode side 54 adjacent to reaction passage 10 .
A first permeate portion of the oxygen contained within oxygen containing gas 28 is transported 30 to combustion passage 44 to support combustion site 20 and to provide oxygen. A second permeate portion of oxygen is transported 30 ′ through the second oxygen selective ion transport membrane element 50 to support a partial oxidation reaction in the reaction passage. The heat required by the endothermic reforming reaction is partially supplied by the partial oxidation reaction and partially by combustion of fuel in combustion passage 44 . By proportioning the mass flow rate of the fuel 32 relative to the light hydrocarbon mass flow rate of process gas 12 , the H 2 /CO molar ratio in product gas 14 is controlled. A high fuel to natural gas ratio favors a high H 2 /CO molar ratio because such a configuration depresses the partial oxidation reaction in the reaction passage and promotes reforming.
In this configuration it is also possible to use an impervious barrier in place of the second ion transport membrane 50 and thereby confine the reactions in the reaction passage 10 to steam reforming.
In an embodiment of the invention illustrated in FIG. 5, the first oxygen-selective ion transport membrane element 18 separates the air passage 26 from the combustion passage 44 whereby combustion products 48 are essentially free of NOx.
In this embodiment, the combustion passage 44 is separated from reaction passage 10 by a second oxygen-selective ion transport membrane element 50 . The second oxygen-selective ion transport membrane element 50 has a second cathode side 52 that is adjacent to the combustion passage 44 and a second anode side 54 that is adjacent to the reaction passage 10 .
Oxygen contained within the oxygen-containing gas 28 is transported 30 through the first oxygen-selective ion transport membrane element to support combustion at the combustion site 20 . The quantity of oxygen transferred is in excess of that required for combustion thereby establishing an oxygen partial pressure between that in air passage 26 and that in reaction passage 10 . If the partial oxygen pressure in the combustion passage 44 is maintained at a level intermediate to the partial oxygen pressure of the air passage 26 and the partial oxygen pressure of the reaction passage 10 , excess oxygen contained within the combustion passage 44 is transported 30 ′ through the second oxygen-selective ion transport membrane element to the reaction passage 10 .
The fuel 32 is below stoichiometric requirements (lean) and distributed along the length of the combustion passage 44 to facilitate a uniform oxygen partial pressure throughout the combustion passage. By control of the mass flow rate of the oxygen containing gas 28 , the fuel 32 and the process gas 12 , the required partial oxygen pressure distribution is achieved. In this embodiment, the heat required by the endothermic reforming reaction is partially provided by the partial oxidation reaction in the reaction passage and partially by the combustion of fuel in combustion passage 44 .
While the above process flows illustrate reforming utilizing steam, it is recognized that carbon dioxide may replace either a portion or all of the steam in any one of the above embodiments.
FIG. 6 illustrates in cross-sectional representation a reactor 60 particularly suited for the process flow illustrated in FIG. 4 . The reactor 60 has a hollow shell 62 defining an enclosure. Fuel tube 36 has a first end 38 and an opposing second end 40 . A tubular first oxygen selective ion transport membrane element 18 circumscribes at least a portion of the fuel tube 36 . The first oxygen selective ion transport membrane element 18 has an anode side 24 adjacent to the fuel tube 36 and an opposing cathode side 22 .
A second ion transport element 50 surrounds ion transport element 18 defining an annulus 26 between cathode sides 22 , 52 . Exterior to the second anode side 54 is a reforming enhancing catalyst 16 which extends over the length of the center reaction section. A preheat section extends from the process gas entry 12 to the reaction section and a heat recovery or cooling section from the bottom of the reaction section to the product exit 14 . The incorporation of preheat and cooling sections in the reactor reduces the temperature at the tube sheets, permitting use of ordinary engineering materials such as carbon and stainless steel and eases making tube to tube sheet joints and seals.
Fuel 32 is introduced to the reactor 60 . For example, a combination of reactor top head 64 and first tube sheet 66 could form a manifold to connect the source of the fuel 32 to the first end 38 of fuel tube(s) 36 .
A source of oxygen containing gas 28 , such as air, provides an air flow along cathode sides 22 and 52 . The combination of the reactor bottom head 68 and a second tube sheet 70 define a manifold to connect the source of the oxygen-containing gas 28 to the air passage 26 which is bounded by the cathodes 22 and 52 of the first oxygen selective ion transport membrane element 18 and the second oxygen selective ion transport membrane 50 , respectively.
Process gases 12 are delivered to the reactor 60 on the shell side, or outside of the second oxygen selective ion transport membrane element 50 . Process gases 12 are preheated against hot oxygen depleted air in the preheat section and then enter the reaction zone where they react with oxygen being transported 30 ′ across second ion transport membrane 50 from air passage 26 in a partial oxidation reaction and with each other in a reforming reaction to produce syngas of the required H 2 /CO ratio. The resulting product is cooled against incoming air and leaves the reactor as product gas 14 .
The heat for the endothermic steam reforming reaction is partially supplied by the exothermic partial oxidation reaction and partially by the reaction of fuel, introduced via process gas 12 and fuel feed tube 38 , with oxygen permeating by ion transport across ion transport membrane 50 within combustion passage 44 . Heat released by the combustion of fuel in combustion passage 44 is transferred by radiation and convection to the reaction passage 10 . The configuration consisting of concentric tubes is favorable for radiation heat transfer. High convective coefficients can be achieved by small annulus width and/or high gas velocities.
Since ion transport tube 50 is impermeable to nitrogen, the combination of third tube sheet 72 , second tube sheet 70 and bottom cover 73 forms a nitrogen impervious barrier. Atmospheric nitrogen is excluded from the combustion passage 44 and the formation of nitrous oxides minimized. Since the combustion passage 44 and the reaction passage 10 are independent of each other, a low value fuel can be employed in the combustion passage 44 .
The composition of the product gas 14 is controlled by controlling the composition and mass flow rate of process gas 12 and the mass flow rate and concentration of fuel 32 . To promote complete combustion it is preferable to keep the fuel/oxygen ratio in combustion passage 44 on the lean side. As described previously, optionally the second end 40 of the fuel tube 36 can be capped and fuel introduced through a plurality of orifices in the wall of the fuel tube to better control combustion site 20 .
Air for the supply of oxygen to both the partial oxidation and the combustion reactions is introduced into air passage 26 through connection 75 and orifices 77 . Products of combustion from combustion passage 44 and oxygen depleted retentate from air passage 26 discharge into common space 79 from where they leave the reactor through connection 81 .
To permit unrestrained changes in length of the fuel tube 36 and first 18 and second 50 oxygen selective ion transport membrane element tubes caused by thermal and compositional changes, a combination of fixed and sliding seals are employed. The use of fixed and sliding seals in a shell reactor is described in more detail in U.S. patent application Ser. No. 09/089,372. Fuel tube 36 is restrained at first end 38 by being fixedly bonded to the first tube sheet 66 . The opposing second end 40 is free-standing and compensates for axial changes in dimension.
The first oxygen selective ion transport membrane element 18 has a first end 76 fixedly bonded to the second tube sheet 70 and a second end 78 that is free-standing to compensate for axial changes in dimensions.
Second ion transport membrane tube 50 is fixedly attached to bottom cover 73 and sliding seals 80 located on the third tube sheet 72 and fourth tube sheet 74 slidably support the second oxygen selective ion transport membrane element 50 to permit unrestrained axial changes in dimension. To reduce the service severity for sliding seals 80 and to enhance safety, a buffer gas 82 , such as steam may be introduced between the sliding seals and fourth tube sheet 74 . A buffer gas provision is only illustrated at the bottom seal. If desired, a similar buffer gas provision is added at the top sliding seal with the addition of a tube sheet and shell connection. The buffer gas is delivered at a pressure that is slightly greater than the pressure of either the process gas 12 or the product gas 14 so that should sliding seals 80 leak, steam, a constituent of the steam reforming reaction will flow into the reactor enclosure. As a result, the requirements for the quality of the sliding seals can be relaxed substantially and leakage of reactive gases into oxygen containing spaces avoided.
Process side gases traverse the reactor in cross-counterflow guided by cross baffles 84 in the preheat and cooling sections and, optionally, also in the reaction section to achieve high heat transfer coefficients and, if employed in the reaction section, to compensate for flow maldistribution and nonuniform reaction kinetics.
If it is desired to produce syngas with H 2 /CO molar ratios of 3 or greater, second ion transport membrane tube 50 can, optionally, be replaced by an impervious barrier tube made from a metal or ceramic. In this embodiment, all the heat for the reforming reaction is supplied by the combustion of fuel.
Air passage 26 can function as a thermal insulator between combustion site 20 and reaction passage 10 . To counter this effect by achieving a high air velocity and high convective heat transfer coefficient, the width of the air passage 26 should be small, preferably less than 5 mm and more preferably in a range of from about 1 to 3 mm. This is especially important in the pure reformer embodiments where more heat has to be transferred from the combustion site to the reforming reaction. Alternatively, the combustion passage and the air passage can be interchanged so that the combustion passage is located adjacent to the reforming passage. This alternative improves heat transfer in the reaction zone, but impedes heat transfer in the preheat and cooling zones.
FIG. 7 illustrates in cross-sectional representation a reactor 90 in which the reforming (reaction) passage 10 with catalyst 16 is disposed within the first tubular oxygen selective ion transport membrane element 18 . The first oxygen selective ion transport membrane 18 together with first and second tube sheets 66 , 70 defines a nitrogen impervious barrier for the reaction zone. Second ion transport membrane tube 50 surrounds ion transport membrane tube 18 and defines an air passage 26 annulus bounded by the cathode sides 22 , 52 of the two ion transport membranes 18 , 50 . A combustion passage 44 is disposed shell side and outside the second oxygen selective ion transport membrane element 50 and may contain baffles 86 to enhance heat transfer and to compensate for flow maldistribution and nonuniform heating effects. As disclosed above, the reactor contains a reaction section, a preheat section and a cooling section.
An oxygen-containing gas 28 , typically air, is introduced to air passage 26 . A first permeate portion of the oxygen contained within the air 28 is transported 30 to the reaction passage 10 for a partial oxidation reaction. A second permeate portion is transported 30 ′ to combustion passage 44 . A fuel 32 is also delivered to the combustion passage 44 and reacted with the permeate oxygen at combustion site 20 generating the required supplementary heat for the endothermic reaction occurring in reaction passage 10 .
Process gas 12 is introduced to the reactor 90 and is connected to process gas tube 92 . The connection may be by a manifold formed by the combination of reactor top head 64 and first tube sheet 66 . The process gas is introduced through multiple orifices 94 in the process gas tube 92 which is flared at the entrance end and sealed to tube sheet 66 . The process gas tube 92 extends to the reaction section and forms a narrow flow annulus 95 between its outside diameter and the inside diameter of ion transport tube 18 to enhance heat transfer coefficients in the preheat section on the process gas side. A similar arrangement is used for the cooling section and discharge from the bottom end of tube 18 . Process gas tube 92 and its discharge counterpart 97 are preferably formed from metal.
The first oxygen selective ion transport membrane element 18 is fixedly joined at one end, such as to second tube sheet 70 and is slidably attached to opposing first tube sheet 66 to permit unrestrained axial expansion resulting from thermal and compositional changes. The second oxygen selective ion transport membrane element 50 is fixedly joined at one end, such as to the third tube sheet 72 and is unrestrained at the opposing end to allow unrestrained axial expansion from changes in the axial length due to temperature and compositional variation.
As with earlier embodiments, staged and steam buffered sliding seals may be employed.
If a pure reformer is preferred for the reactor 90 design, the first oxygen selective ion transport membrane element 18 may be replaced with a metallic or ceramic tube that does not transport oxygen ions.
FIG. 8 illustrates a reactor 100 having reaction passage 10 and combustion passage 44 located in separate tubes within the reactor 100 enclosure. Combustion is supported by fuel 32 that is connected to fuel tube 36 such as by a manifold defined by reactor bottom head 68 and first tube sheet 66 . The fuel 32 is delivered to the combustion passage 44 through orifices 42 , or alternatively, through an open second end of the fuel tube as described above.
Fuel tube 36 defines one surface of the combustion passage 44 . The opposing surface is defined by the anode side 24 of a first oxygen selective ion transport membrane element 18 . An oxygen-containing gas 28 , typically air, flows shell side along the cathode side 22 of the oxygen selective ion transport membrane element. A portion of the contained oxygen is transported 30 through the oxygen selective ion transport membrane and this permeate oxygen portion combines with the fuel 32 at combustion site 20 generating the heat supporting steam reforming in reaction passage 10 .
Separated from the combustion reaction, the reforming reaction occurs by the delivery of process gas 12 to the catalyst laden reaction passage 10 , formed by the annulus between product withdrawal tube 81 and ion transport membrane tube 50 , where, in the presence of catalyst 16 , the process gas is converted to product gas 14 , typically syngas. A nitrogen impervious barrier separates the reaction passage 10 from the oxygen containing gas 28 flowing within the reactor 100 enclosure. If a partial oxidation reaction is to be supported in the reaction passage 10 , then the nitrogen impervious barrier constitutes a second oxygen selective oxygen selective ion transport membrane element 50 having a second cathode side 52 in contact with the flowing oxygen containing gas 28 such that a portion of the oxygen contained within the oxygen containing gas 28 is transported 30 ′ to the second anode side 54 . If pure steam reformation is desired, the nitrogen impervious barrier is formed from a metal or a ceramic that does not transport oxygen ions.
Air traverses the shell side in cross-counterflow. The reactor 100 may include cross flow baffles 84 to guide the flow, generate high velocities, enhance heat transfer and compensate for flow maldistribution and nonuniform reactions between individual tubes. The heat from the combustion reaction of fuel is transferred to the reaction passage by radiation and convective heat transfer.
The first oxygen selective ion transport membrane 18 is fixedly attached at one end to first tube sheet 66 with the opposing second end of the oxygen selective ion transport membrane element 18 free-floating. Likewise, the second oxygen selective ion transport membrane element 50 is fixedly attached at a first end to the second tube sheet 70 and has a free-floating opposing second end. This reactor design permits unrestrained axial changes in dimension without requiring any sliding seals.
The seal between the first tube sheet 66 and the first oxygen selective ion transport membrane element 18 must withstand only a relatively small pressure difference and may be readily fashioned by conventional means, such as a metallic braze between a metal tube sheet and a metallized tube end. The seal between the second tube sheet 70 and the second oxygen selective ion transport membrane element 50 must withstand a significantly higher pressure difference. While a conventional seal could be sufficient, it is within the scope of the invention to stage the seal by the introduction of a buffer gas between the process gas 12 inlet 102 and the seal. As a result, any leakage into the hollow shell around the seal will be buffer gas, such as steam, rather than hydrocarbons.
While FIG. 8 illustrates a single pair of tubes, a typical reactor will contain multiple tubes which are spaced and loosely supported by densely spaced cross baffles to provide for efficient heat transfer. FIG. 9 schematically illustrates a portion of an exemplary tube bundle having rows of tubes containing a reaction passage 10 alternating with rows of tubes containing a combustion passage 44 . Of course any other suitable tube configuration is also amenable to the reactors of the invention. | Syngas, a mixture of hydrogen and carbon monoxide, is an intermediate in the conversion of methane to liquid fuels. For certain applications, it is desirable to maintain an H 2 /CO molar ratio of about 3. This molar ratio is achieved by steam reforming of methane in accordance with:
CH 4 +H 2 O→3H 2 +CO.
To provide the heat required to drive the endothermic steam reforming reaction, a low grade fuel is combusted in a reactor and the heat of combustion conducted to the endothermic reaction. By using an oxygen selective ion transport membrane element to transport the oxygen required for combustion, the formation of undesirable NOx compounds is minimized. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application Serial No. 60/320,060, filed Mar. 27, 2003, which is incorporated herein in its entirety.
BACKGROUND OF INVENTION
1. Field of the Invention
The invention relates generally to fishing reels and more particularly to a removable spool support for supporting a spool of fishing line in the proper position during installation of the fishing line on a fishing reel.
2. Description of the Related Art
Fishing line used in sportfishing is available in a wide range of materials, sizes, and performance properties. Selection of the appropriate fishing line will depend upon several factors such as the type of fishing (bait fishing, flyfishing, spin casting), the type of water (freshwater v. salt water, stream fishing v. lake fishing v. ice fishing), the size of the fish pursued, etc. A sportsman active in several different types of fishing may need to use a variety of fishing lines which are readily exchangeable. A selection of fishing lines can be provided in several ways.
Several different replaceable reel spools for each fishing reel, each holding a selected fishing line, can be used. When a particular line is to be used, the reel spool holding that line is exchanged for the reel spool currently on the reel. Alternatively, the fishing line on a particular reel spool can be removed and replaced With the desired line.
In the first instance, maintaining a supply of reel spools can be expensive. In the latter instance, changing line, particularly if it must be done frequently, can be time-consuming and inconvenient. In particular, fishing line must be carefully wound from the supply spool onto the reel spool in order to avoid twisting the line or excessively stretching the line, which can lead to line entanglement during use or premature line failure. Furthermore, all fishing line deteriorates with age and use, and must be periodically replaced with fresh line.
Typically, a sportsman needing to have new fishing line installed on a fishing reel must arrange for a sporting goods store having the proper equipment to install the line. This can be inconvenient, as well as costly. Furthermore, such an option is unworkable if the line must be replaced in the field.
SUMMARY OF INVENTION
A device for installing a length of fishing line onto a fishing reel mounted onto a fishing rod having a longitudinal axis comprises a spool holder adapted to receive a spool containing the length of fishing line, wherein the spool is mounted for rotatable movement with respect to the spool holder, a quick-release clamp, wherein the quick-release clamp has a retainer mounted thereto for movement between a clamping position wherein the retainer is adapted to retain a portion of the fishing rod and a release position wherein the retainer is opened to allow removal of the clamp from the portion of the fishing rod, and a support arm connecting the spool holder to the quick-release clamp, whereby, when a user of the fishing rod desires to install the length of fishing line onto the fishing reel, the quick-release clamp, in its release position, is positioned over a length of the fishing rod generally distal from the fishing reel, and the quick-release clamp is moved to its clamping position so that the quick-release clamp is retained on the rod whereby a spool of additional fishing line can be rotatably mounted on the spool holder and the fishing line from the spool can be fed onto the fishing reel in a convenient manner. In one embodiment, a spring biases the quick-release clamp to the clamping position. In another embodiment, a spool retainer retains the spool on the spool holder. In yet another embodiment, the spool retainer is a flanged nut. The flanged nut can be tightened against the spool to restrain the spool against rotating. A spring can be inserted between the spool retainer and the spool.
In another embodiment, the support arm is inclined relative to the spool holder. In yet another embodiment the support arm comprises a lower linkage, an upper linkage, and a pivotal connection therebetween for pivotal movement of the upper linkage relative to the lower linkage. In another embodiment, the quick-release clamp, the spool holder, and the support arm lie in a plane orthogonal to the longitudinal axis of the fishing rod. In another embodiment, the spool further comprises a crank for rotating the spool to retrieve line from the reel onto the spool.
In another embodiment, an assembly for installing fishing line onto a fishing reel comprises a fishing rod having a longitudinal axis, a fishing reel mounted to the fishing rod at a first end thereof, at least one eyelet adapted to route the fishing line along the length of the rod, and a line feeding device comprising a spool holder adapted to receive a spool containing the length of fishing line, wherein the spool is mounted for rotatable movement with respect to the spool holder, a quick-release clamp, wherein the quick-release clamp has a retainer mounted thereto for movement between a clamping position wherein the retainer is adapted to retain a portion of the fishing rod and a release position wherein the retainer is opened to allow removal of the clamp from the portion of the fishing rod, and a support arm connecting the spool holder to the quick-release clamp, whereby, when a user of the fishing rod desires to install the length of fishing line onto the fishing reel, the quick-release clamp, in its release position, is positioned over a length of the fishing rod generally distal from the fishing reel, and the quick-release clamp is moved to its clamping position so that the quick-release clamp is retained on the rod whereby a spool of additional fishing line can be rotatably mounted on the spool holder and the fishing line from the spool can be fed onto the fishing reel in a convenient manner.
In another embodiment, a method of installing fishing line from a spool of replacement fishing line onto a fishing reel mounted to a fishing rod comprises the steps of detachably mounting the spool of replacement fishing line to the fishing rod for rotatable movement of the spool with respect thereto in a generally spaced relationship with respect to the fishing reel, threading the fishing line from the spool of replacement fishing line to the fishing reel, attaching the fishing line to the fishing reel, and winding the fishing line onto the fishing reel. In another embodiment, the method can comprise the step of restraining rotation of the spool of replacement fishing line to vary the tension of the fishing line being wound onto the fishing reel. In yet another embodiment, the method can comprise the step of rotating the spool to unwind fishing line from the fishing reel onto the spool.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings:
FIG. 1 is a perspective view of a fishing rod and fishing reel having an attached fishing line feeder spool support according to the invention for installing fishing line on the fishing reel.
FIG. 2 is a front elevational view of a first embodiment of the fishing line feeder spool support of FIG. 1 .
FIG. 2A is a partial perspective view of a portion of the fishing line feeder spool support of FIG. 2 .
FIG. 3 is a front elevational view of a second embodiment of the fishing line feeder spool support of FIG. 1 .
FIG. 4A is a front elevational view of the fishing line feeder spool support of FIG. 2 with a line storage spool for removing and storing fishing line from the fishing reel.
FIG. 4B is a side elevational view of the line storage spool of FIG. 4 A.
FIG. 5 is a front elevational view of a third embodiment of the fishing line feeder spool support of FIG. 1 .
FIG. 6 is a front elevational view of a fourth embodiment of the fishing line feeder spool support of FIG. 1 comprising a pivotable support arm and shown in an unfolded position.
FIG. 7 is a front elevational view of the fishing line feeder spool support of FIG. 7 shown in a folded position.
FIG. 8 is a close-up perspective view of the pivotable support arm of FIGS. 6 and 7.
DETAILED DESCRIPTION
Referring to the figures, and to FIG. 1 in particular, a well-known fishing rod 10 is shown mounting a fishing reel 12 , shown in FIG. 1 as a conventional spinning reel, in a well-known manner. The fishing reel 12 comprises a reel spool 20 and a bail 22 operated by a crank 24 for playing out and retrieving fishing line 18 . The fishing line 18 is threaded through a first line guide 14 followed by a plurality of line guides 16 mounted in a conventional manner along the rod 10 . It will be understood that, although the fishing reel 12 is shown for exemplary purposes as a spinning reel, the invention is not so limited and can be used with any fishing reel, such as a fly reel or a baitcasting reel.
A fishing line feeder spool support 30 is shown in FIG. 1 attached to the rod 10 as hereinafter described between the first line guide 14 and an adjacent line guide in the plurality of line guides 16 , and holding a spool 60 containing a supply of fishing line to be installed on the reel spool 20 . FIG. 1 shows the fishing line feeder spool support 30 suspended from the rod 10 to hang from the rod 10 for operable juxtaposition with the reel 12 . However, the fishing line feeder spool support 30 can alternatively be attached to the rod 10 to extend upwardly for operable juxtaposition with a fishing reel that is mounted to an upper side of the rod, such as a bait-casting reel.
FIG. 2 shows a first embodiment of the fishing line feeder spool support 30 as a generally L-shaped member comprising a quick-release clamp 32 and a spool holder 34 . The quick-release clamp 32 comprises a first arm 36 and a second arm 38 joined at a bight section 40 , and defines a longitudinal axis 28 . In the preferred embodiment, the first arm 36 comprises a generally elongated strap-like member comprising a straight section 42 transitioning to a crossing section 44 inclined therefrom to cross the longitudinal axis 28 , and terminating in an arcuate retainer 46 . The retainer 46 has a radius of curvature adapted for cooperative register of the retainer 46 with the shaft of the fishing rod 10 .
The crossing section 44 has a somewhat narrower cross-section than the straight section 42 (FIG. 2 A). The arcuate retainer 46 has an inner surface 48 which is adapted to frictionally communicate with the shaft of the fishing rod 10 , and can be provided with a material, such as rubber, that will not mar the shaft of the fishing rod 10 and will enhance the frictional force between the retainer 46 and the shaft of the fishing rod 10 .
The second arm 38 comprises a generally elongated strap-like member generally identical to the first arm 36 and comprising a straight section 42 transitioning to a crossing section 44 inclined therefrom to cross the longitudinal axis 28 in opposed juxtaposition to the first arm 36 . The second arm 38 terminates in an arcuate retainer 46 having a radius of curvature adapted for cooperative register of the retainer 46 with the shaft of the fishing rod in opposed juxtaposition to the arcuate retainer 46 of the first arm 36 . The crossing section 44 of the second arm 38 also has a somewhat narrower cross-section than the straight section 42 . The arcuate retainer 46 of the second arm 38 has an inner surface 48 which is adapted to frictionally communicate with the shaft of the fishing rod 10 , and can be provided with a material, such as rubber, that will not mar the shaft of the fishing rod 10 and will enhance the frictional force between the retainer 46 and the shaft of the fishing rod 10 . The first arm 36 and the second arm 38 are operably joined at the bight section 40 so that the arcuate retainers 46 are in cooperative juxtaposition as shown in FIG. 2 to form an attachment portion for attaching the fishing line feeder spool support 30 to the shaft of the fishing rod 10 . The crossing sections 44 of the first arm 36 and the second arm 38 are adapted so that the crossing sections 44 will clear each other at the point of crossing due to the reduced cross-section of the crossing sections 44 , as shown in FIG. 2 A.
Extending away from the retainers 46 generally collinearly with the longitudinal axis 28 of the quick-release clamp 32 is an elongated support arm 50 which is rigidly attached to the bight section 40 generally parallel to the straight sections 42 . An elongated, rod-like spool shaft 52 is rigidly attached to the support arm 50 orthogonal thereto comprising a threaded section 54 adapted for threadable communication with an inner flanged nut 56 and an outer flanged nut 58 . The spool shaft 52 is adapted to receive the spool 60 of fishing line which rotates about the spool shaft 52 as line is removed from the spool 60 . The flanged nuts 56 , 58 can be turned on the threaded section 54 to hold the spool 60 in a selected position on the spool shaft 52 . The flanged nuts 56 , 58 can also be selectively tightened against the spool 60 to control its rotation and maintain a selected tension on the fishing line during installation of the fishing line on the reel 12 . As shown in FIG. 5, a spool spring 86 , preferably comprising a conventional helical spring, can be inserted over the spool shaft 52 to bear against one of the inner flanged nuts 56 , 58 and the spool 60 containing the fishing line. The flanged 56 , 58 can be selectively tightened against the spool 60 to compress the spring 86 and thereby control the rotation of the spool 60 and the tension on the fishing line during installation.
Preferably, the first arm 36 , the second arm 38 , and the bight section 40 are fabricated from a single piece of material and stamped or bent to the desired configuration. Alternatively, the arms 36 , 38 can be fabricated of separate pieces, each comprising half of the bight section 40 , and joined together at or below the bight section 40 along the support arm 50 , such as by spot welding or suitable fasteners, to form the quick-release clamp 32 . Preferably, the quick-release clamp 32 is fabricated of a stiff, resilient material, such as spring steel or a high strength plastic, which can be repeatedly deflected laterally and will return to its original configuration, so that inward pressure on the straight sections 42 will result in separation of the retainers 46 , and release of the pressure will result in the return of the arms 36 , 38 to their at-rest configuration to impart a clamping force to the section of rod 10 inserted therebetween.
FIG. 3 illustrates a second embodiment of the feeder spool support 30 in which the crossing sections 44 have a somewhat arcuate shape transitioning smoothly into the retainers 46 . Additionally, the inner flanged nut 56 is replaced with a spool stop 64 . The spool stop 64 is a generally circular platelike flange rigidly attached to the spool shaft 52 and against which the spool bears. The outer flanged nut 56 can be threadably tightened on the threaded section 62 against the spool 60 to maintain a selected tension on the fishing line during installation of the fishing line on the reel 12 .
FIG. 3 also illustrates an alternate assembly for developing the clamping force of the retainers 46 . A spring 78 is inserted between the first arm 36 and the second arm 38 to provide a clamping force additional to the force resulting from the resiliency of the arms 36 , 38 . The spring 78 is retained in a preselected position between the arms 36 , 38 through a suitable retainer, such as a pair of inwardly-extending retainer posts 79 rigidly attached to the arms 36 , 38 over which the ends of the spring 78 can be inserted. It will be understood that the spool stop 64 and the spring 78 can be incorporated into any of the other embodiments shown and described herein.
FIG. 5 shows a third embodiment of the feeder spool support 30 in which the support arm 50 is replaced with a first support arm 80 rigidly attached to the spool shaft 52 orthogonally thereto, an inclined arm 82 rigidly attached to the support arm 50 and inclined away from the spool shaft 52 , and a second support arm 84 rigidly attached to the inclined arm 82 parallel to the first support arm 80 so that the quick-release clamp 32 is centered over the spool holder 34 , thereby balancing the spool holder 34 beneath the fishing rod 10 in line with the fishing reel 12 .
FIG. 4A shows an embodiment of the feeder spool support 30 provided with a line storage spool 66 comprising a center hub 68 , a circular plate-like inner flange 70 and a circular plate-like outer flange 72 coaxially attached to the hub 68 in parallel spaced-apart juxtaposition, an aperture 74 extending through the flanges 70 , 72 and the hub 68 , and a crank handle 76 rotatably attached to the outer flange 72 adjacent the circumference thereof. The storage spool 66 is adapted to be rotatably received over the support arm 50 and to be turned via the crank handle 76 for removing and storing fishing line from the fishing reel 12 .
FIGS. 6-8 show a fourth embodiment of the feeder spool support 30 in which the support arm 50 is hinged. The support arm 50 comprises a lower linkage 90 and an upper linkage 92 pivotably joined by a suitable connection, such as a pinned connection 94 . As shown in FIG. 8, the upper linkage 92 terminates in a pair of parallel, spaced-apart arms 100 adapted for pivotable insertion of the lower linkage 90 therebetween. The arms 100 are provided with suitable pin apertures adapted for coaxial alignment with a mating aperture in the lower linkage 90 for insertion of a pin therethrough in a well-known manner to form the pivotal connection 94 .
Each arm 100 is provided with an inwardly-extending boss 98 in opposed juxtaposition and adapted for operable register with mating detents 96 in the lower linkage 90 . The bosses 98 and detents 96 provide an interference fit which will retain the lower linkage 90 in collinear relation to the upper linkage 92 , as shown in FIG. 6 . The upper linkage 92 can be selectively pivoted relative to the lower linkage 90 as shown in FIG. 7 to fold the quick-release clamp 32 adjacent the spool holder 34 in a compact configuration for storage and transportation. The bosses 98 and the detents 96 can be easily engaged and disengaged for folding and unfolding the quick-release clamp 32 relative to the spool holder 34 .
The fishing line feeder spool support 30 is an easily installed device for holding a supply spool of fishing line 18 at a proper orientation for readily loading the line 18 onto a fishing reel 12 . The tension on the fishing line 18 as it is loaded onto the reel 12 can be easily adjusted to provide the proper installation of the line 18 . The fishing line feeder spool support 30 can be used at home, along a stream, or in a boat for quickly and easily changing fishing line 18 when fishing conditions change. The fishing line feeder spool support 30 eliminates the necessity of relying upon a sporting goods store for installation of fishing line on a fishing reel, or maintaining multiple reel spools of fishing line in order to quickly change fishing line while in the field.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the foregoing disclosure and drawings without departing from the scope of the invention. | A fishing line feeder spool support comprises a pair of flexible arms which are adapted to grip a fishing rod ahead of a fishing reel mounted thereon. The feeder spool support comprises a threaded shaft which rotatably supports a spool of fishing line while the fishing line is installed onto the fishing reel through the operation of the reel crank. A flanged nut is threaded onto the shaft to hold the spool. The line tension can be adjusted by tightening the flanged nut against the spool, thereby adjusting the pulling force needed to remove line from the supply spool. A crankable supply spool can also be installed on the shaft to remove and store fishing line from the fishing reel for later replacement on the reel. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field radiation detection and more particularly to single crystal scintillation detectors for gamma rays, x-rays and like radiation.
BACKGROUND OF THE INVENTION
[0002] Transparent single crystal scintillators are well known in the art for use as detectors of gamma rays, x-rays, cosmic rays, other types of high energy radiation and energetic particles of approximately 1 KeV or above. When radiation is incident on the scintillator secondary photons are generated within the crystal. These secondary photons result from the interaction of the incident radiation and an activation ion contained within the crystal. Once produced, the secondary photons can be optically coupled to a photodetector so as to produce a voltage signal that is directly related to the number and amplitude of the secondary photons. Such crystal scintillators are typically employed for medical imaging such as Positron Emission Tomography (PET), digital radiography, mineral and petroleum exploration.
[0003] An ideal detector for the detection of the above radiation and particles employs a single crystal scintillator characterised in that it exhibits:
[0004] A high density so as to provide a high stopping power on the aforesaid radiation or particles;
[0005] A high light output, this results in the production of bright visible light, typically in the blue/UV region of the electromagnetic spectrum, in response to the absorption of the aforesaid radiation or particles;
[0006] A good energy resolution, which is an important characteristic as it allows good event identification, for example in PET applications;
[0007] A short decay time, associated with the ions excited by the aforesaid radiation or particles, so as to provide detectors with a fast response time; and
[0008] A rugged structure so as to reduce the opportunity of accidental damage.
[0009] The Prior Art teaches of various single crystal scintillator materials that have been employed in an attempt to satisfy the above criteria. One of the earliest types of scintillator employed was Thallium doped Sodium Iodide (NaI:Tl). Although capable of producing very high light outputs and being relatively inexpensive to produce NaI:Tl exhibits an inherently low density and so has a low incident radiation absorption efficiency. In addition, NaI:Tl is hygroscopic, has a slow scintillation decay time and produces a large persistent afterglow that acts to impair the counting rate performance of the material.
[0010] Table 1 provides a summary of some of the main characteristics of NaI:Tl as well as other known scintillator materials. The data within this table are taken from papers and Patents that teach of the relevant crystals, as discussed below. It should be noted that:
[0011] The light output values are relative values measured relative to the light output of NaI:Tl;
[0012] The decay times are measured in nanoseconds and refer to the time it takes for a particular activation ion of a crystal scintillator to luminesce from the excited electronic state;
[0013] The density values are measured in g/cc;
[0014] The emission peak wavelengths are measured in nanometers; and
[0015] The melting point values are measured in ° C.
[0016] Inorganic metal oxides provide alternative single crystal scintillators devised for gamma ray detection and the like. For example a commonly employed inorganic metal oxide crystal is Bismuth Germanate (BGO). As well as being denser than NaI:Tl, BGO does not suffer from being hygroscopic. However, BGO scintillators have even slower scintillation decay times, exhibit lower light output levels that drop further with increasing temperatures and exhibit poor energy resolution values, as compared to NaI:Tl. In addition the refractive index values for BGO scintillators are relatively high so resulting in significant levels of light being lost through internal reflection processes within the crystal.
[0017] Attempts have been made to develop alternative single crystal scintillators that improve on the inherent characteristics of the aforementioned crystals. For example, Cerium activated Yttrium Orthosilicate (YSO) crystals have been developed while European Patent Application No. EP 0,231,693 teaches of a Cerium activated Gadolinium Orthosilicate (GSO) scintillator. The characteristic properties for both of these crystals are summarised in Table 1. Although exhibiting significantly faster scintillation decay times than NaI:Tl or BGO, both YSO and GSO have low densities. The light output and energy resolution values exhibited by YSO are generally good, however the inherent low density makes it a poor candidate for applications such as PET. GSO exhibits a lower light output than YSO but does have a higher density. However, the inherent poor mechanical properties of GSO make such crystals expensive to produce.
[0018] Another material that has been the subject of much development over the last few years is Cerium activated Lutetium Silicate (LSO) as taught in U.S. Pat. No. 4,958,080 and the equivalent European Patent No. 0,373,976. In particular LSO has become one of the most common crystals presently employed as a single crystal scintillator in PET as these crystals have good properties for such applications (see Table 1). LSO exhibits a fast scintillation decay time, has a fairly high density, high light output values and an average energy resolution. However, one main drawback of employing LSO as a single crystal scintillator is again the fact that it is an extremely expensive crystal to produce. This is due mainly to the fact that the melting point is very high (typically ˜2100° C.) as compared to other standard oxide crystals.
[0019] Further single crystal scintillators have been developed in attempts to improve on the working characteristics of LSO while reducing the production costs. Such attempts concentrate exclusively on introducing a substitute ion at the site of the Lutetium ions within the original LSO structure. In particular U.S. Pat. No. 6,278,832 and the equivalent European Patent Application No. EP 1,004,899 teach of mixed Lutetium Orthosilicate crystals, commonly referred to as MLS crystals. Alternatively, U.S. Pat. No. 6,323,489 teaches of a single crystal of Cerium activated Lutetium Yttrium Oxyorthosilicate (LYSO). Both MLS crystals and LYSO crystals exhibit similar physical properties to LSO but are still expensive to produce since their melting point is only slightly lower that that of LSO.
[0020] A further restricting factor that is common to LSO, LYSO and MLS crystals is the fact that they all exhibit only average levels of energy resolution, compared to GSO or NaI:Tl.
[0021] U.S. Pat. No. 5,864,141 teaches of a high resolution gamma ray imaging device that employs a Yttrium Aluminium Perovskite (YAP) crystal scintillator while U.S. Pat. No. 5,864,141 teaches of a gamma ray detector based on a Yttrium Aluminium Perovskite (YAP) crystal. A YAP single crystal scintillator is found to exhibit very fast scintillation decay times and provide very good energy resolution and light output levels. However, YAP exhibits low density levels and is again an expensive crystal to produce. The fact that YAP has superior energy resolution than LSO is due to the fact that LSO exhibits a strong non-linearity of energy response which YAP does not suffer from. The superior energy resolution has been attributed to the perovskite structure.
[0022] An alternative single crystal scintillator to YAP that is also based on the Aluminium Perovskite structure, is LuAP, which has also been known to those skilled in the art for over a decade. For example, U.S. Pat. No. 5,961,714 teaches of a method of growing Cerium activated Lutetium Aluminium Perovskite (LuAP). LuAP crystal has a significant advantage over YAP in that it exhibits a much higher density and hence a higher stopping power. This characteristic makes LuAP extremely attractive as a gamma-ray scintillator and in particular for employment within PET applications.
[0023] The main drawback with LuAP is that it is extremely difficult to manufacture due to the fact that it is metastable at high temperature, which causes decomposition of the perovskite phase at high temperature. Therefore, to date attempts to manufacture LuAP have yielded only small size samples.
[0024] Research work has also been conducted on mixed Lutetium Yttrium Aluminium Perovskite crystals e.g. Cerium activated LuYAP, which is basically a mixed crystal of LuAP and YAP. Several references, such as:
[0025] “Growth and Light Yield Performance of Dense Ce 3+ doped (Lu,Y)AlO 3 Solid Solution Crystals”, by Petrosyan et al, JCG 211 (2000) 252-256;
[0026] “Development of New Mixed Lu (RE 3+ ) AP:Ce Scintillator: Comparison With Other Ce Doped or Intrinsic Scintillating Crystals”, by Cheval et al, Nuclear Inst. And methods in Phys. Res. A443 (2000) 331-341;
[0027] “Intrinsic Energy Resolution and Light Output of the Lu0.7Y0.3AP:Ce Scintillator”, by Kuntner et al, Nuclear Inst; and
[0028] Methods in Phys. Res. A 493 (2002) 131-136.
[0029] describe the physical properties of a LuYAP crystal that comprises 30% Yttrium and 70% Lutetium. This LuYAP crystal requires such a high level of Yttrium in order for it not to decompose at high temperatures. However, this results in a crystal that exhibits a density and stopping power that is significantly lower than LuAP. For example in the case of LuYAP with a 30% Yttrium level the crystal density becomes comparable with LSO, namely 7.468 g/cc. The decay time of such LuYAP crystals is about 25 ns but there also exists a significant long decay time component that is detrimental to applications where a fast crystal scintillator is preferred.
SUMMARY OF THE INVENTION
[0030] It is clearly desirable to be able to provide an affordable single crystal scintillator having as many of the aforementioned desirable properties as possible. Therefore, it is an object of at least one aspect of the present invention to provide a single crystal scintillator capable of detecting gamma rays, x-rays, cosmic rays and similar high energy radiation as well as energetic particles.
[0031] It is a further object of at least one aspect of the present invention to provide a single crystal scintillator that exhibits good working characteristics while remaining cost effective to produce.
[0032] According to a first aspect of the present invention there is provided a crystal scintillator comprising a transparent single crystal of a Cerium activated mixed Perovskite having a general formula
Ce x Lu (1−x−z) A z Al (1−y) B y O 3 , wherein
[0033] x is within the range of from approximately 0.00005 to approximately 0.2,
[0034] y is within the range of from 0.00005 to approximately 1.0,
[0035] z is within the range of from 0 to approximately (1−x), where A comprises one or more of the following cations: Y, Sc, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, In, Ga and B comprises one or both of the following cations: Sc and Ga.
[0036] According to a second aspect of the present invention there is provided a crystal scintillator comprising a transparent single crystal of a Cerium activated mixed Perovskite having a general formula
Ce x Lu (1−x−z) A z Al (1−y) B y O 3 , wherein
[0037] x is within the range of from approximately 0.00005 to approximately 0.2,
[0038] y is within the range of from 0.0 to approximately 1.0,
[0039] z is within the range of from 0.00005 to approximately (1−x),
[0040] where A comprises one or more of the following cations: Sc, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, In and B comprises one or both of the following cations: Sc and Ga.
[0041] Most preferably A further comprises one or both of the following cations: Y and Ga.
[0042] Preferably x is within the range of from approximately 0.0005 to approximately 0.005, y is within the range of from 0.005 to approximately 0.05 and z is within the range of from 0.0005 to approximately 0.05.
[0043] Preferably the crystal scintillator has a luminescence decay time within the range of from approximately 15 ns to approximately 45 ns.
[0044] Preferably the crystal scintillator has a density of more than 7.5 g/cc.
[0045] Preferably the crystal scintillator generates a luminescence wavelength within the range of from approximately 330 nm to approximately 440 nm.
[0046] Preferably the crystal scintillator generates a luminescence wavelength of approximately 365 nm.
[0047] According to a third aspect of the present invention there is provided a scintillation detector comprising a crystal scintillator in accordance with the first or second aspect of the present invention and a photodetector optically coupled to said crystal scintillator for detecting light emitted from the crystal scintillator.
[0048] According to a fourth aspect of the present invention there is provided a scintillation detector comprising two or more a crystal scintillators and a photodetector optically coupled to said crystal scintillators for detecting light emitted from the crystal scintillators wherein at least one of the crystal scintillators comprises a crystal scintillator in accordance with the first or second aspect of the present invention.
[0049] Preferably the photodetector comprises a detector selected from the group comprising a photo-multiplier, a photo-diode and a charge-coupled device.
DETAILED DESCRIPTION OF THE INVENTION
[0050] Embodiments of the present invention will now be described, by way of example only and with reference to the accompanying Tables, in which:
[0051] Table 1 presents a summary of characterising properties for crystal scintillators taught in the Prior Art as compared with typical characteristics of a crystal scintillator in accordance with aspects of the present invention; and
[0052] Table 2 presents a summary of chemical formulae and starting melts for crystal scintillators produced in accordance with aspects of the present invention.
TABLE 1 Light 100 20 40 20 40 50 25 25 40 Output Energy 7 19 7 11 6 14 7 7 7 Resolution Decay 230 300 40 30 28 40 18 25 20 Time (ns) Density 3.67 7.15 4.45 67 5.5 7A 8.3 7.4 8.2- (g/cc) 8.3 Emission 415 480 420 440 380 428 365 365 365 Peak (nm) Melting 650 1050 1980 1900 1900 2100 1950 1950 1900 Point (° C.) Rugged No Yes Yes No Yes Yes Yes Yes Yes
[0053] [0053] TABLE 2 Ce 0.006 Lu 0.894 Gd 0.1 LuAlO 3 —GdScO 3 8.202 Al 0.9 Sc 0.1 O 3 (Ce 0.006 )Lu (0.984) Gd 0.01 LuAlO 3 —GdScO 3 8.395 Al 0.99 Sc 0.01 O 3 (Ce 0.006 )Lu (0.994 )La (0.05 ) LuAlO 3 —LaGaO 3 8.317 Al (0.95) Ga(0.05) O 3 (Ce 0.006 )Lu (0.964) La (0.03) LuAlO 3 —LaScO 3 8.295 Al (0.97) Ga (0.03) O 3 (Ce 0.006 )Lu (0.894) La( (0.10) LuAlO 3 —LaAlO 3 8.258 Al (0.9) Ga (0.1) O 3 (Ce 0.006 )Lu (0.914) La 0.08 LuAlO 3 —LaAlO 3 8.229 AlO 3 (Ce 0.006 )Lu (0.974) Y 0.02 LuAlO 3 —YGaO 3 8.307 Al 0.98 Ga 0.02 O 3 (Ce 0.006 )Lu (0.974) Y 0.02 LuAlO 3 —YScO 3 8.307 Al 0.98 Sc 0.02 O 3
[0054] In order to produce a commercially viable crystal scintillator it is necessary to develop a material that can be produced by a standard growth process. The following embodiments of the present invention employ the Czochralski growth method to produce the crystal scintillators, although any other growth method may be employed. The Czochralski growth method is described in detail by C. D. Brandle in a paper entitled “ Czochralski Growth of Rare-Earth Orthosilicates ( Ln 2 SiO 5 )” published in the Journal of Crystal Growth, Volume 79, Page 308-315, (1986).
[0055] A further criterion for a commercially viable crystal scintillator is that it should be physically stable at high temperature, a criterion that is currently lacking in LuAP. By substituting a critical amount of Lu or Al by different trivalent cations, the Perovskite structure can be stabilised so as to prevent metastability of the material at high temperature.
[0056] The lack of stability in LuAP can be related to the Goldschmidt tolerance factor that is a measure of the geometric fit of the various atoms based on a hard sphere model and is defined by:
t =( R A +R o )/({square root}{square root over (2)}( R B +R o )) (1)
[0057] where R A =radius of the larger cation, e.g. Lu
[0058] R B =radius of the smaller cation, e.g. Al
[0059] R o =radius of the oxygen anion, i.e. 1.4 Å
[0060] As t becomes larger, i.e. approaches unity, the tendency for stability of the Perovskite structure increases. For a given B cation, e.g. Al, the increase in the tolerance factor is also reflected in the unit cell volume. The condition for better stability at high temperature is to have an approximate value for the critical unit cell volume ranging from about 198.7 Å 3 to 201.3 Å 3 .
Example Lutetium Mixed Perovskite Crystal Scintillators
[0061] In a particular example (a solid solution of LuAlO 3 and GdScO 3 ) is employed to produce a transparent single crystal scintillator, grown by the Czochralski growth method, having a formula:
Ce 0.006 Lu 0.894 Gd 0.1 Al 0.9 SC 0.1 O 3
[0062] Initially the following chemical substances (with respective weights): Lu 2 O 3 (711.5 g), Gd 2 O 3 (72.5 g), Al 2 O 3 (183.9 g), Sc 2 O 3 (27.6 g) and CeO 2 (4.12 g) are loaded into an iridium crucible. The crucible is then loaded into a growth furnace composed of Zirconia insulation and heated by an induction coil under an inert atmosphere containing a small amount of oxygen, typically less than 2%, to prevent evaporation of the various components. The crystal is then pulled from the melt at a slow rate, typically 1 mm/h to 2 mm/h, and using a rotation rate from 10 to 30 rpm. This method provides a crystal scintillator having a density of 8.202 g/cc (see Table 2), the other characterising parameters are as shown in Table 1.
[0063] Further examples of physically stable crystal scintillators grown by the aforementioned Czochralski growth method are presented in Table 2. The starting melt compositions shown were employed since these melts are found to be stable at high temperatures.
[0064] It should also be pointed out that for each of the solid solutions, the “dopant perovskite” e.g. GdScO 3 , LaAlO 3 and YScO 3 is in itself a congruent melting compound and hence a stable compound.
[0065] Seven of the Lutetium Mixed Perovskite crystals described in Table 2 produce Cerium activated Lutetium Mixed Perovskite scintillators where cation substitution has taken place at the Aluminium host sites. In all of the scintillators described in Table 2 a second cation, in addition to the Cerium cations, have been substituted at the Lutetium ions host sites. This has been carried out so as to provide an alternative activation ion and to aid in the chemical stability of the Lutetium Mixed Perovskite crystals.
[0066] The described Lutetium Mixed Perovskite crystals provide a number of clear advantages when compared to other materials described in the Prior Art such as LSO, LuAP or YAP (see Table 1), both from a growth process point of view and a performance point of view.
[0067] Compared with LuAP, the multiple ionic substitutions employed to modify the physical structure improve the thermal stability of the material. This improved thermal stability renders the growth process scalable to commercial levels since it permits improved yields. Such yields are not readily feasible for LuAP due to the inherent metastability of this material at high temperatures.
[0068] The decay time of the described Lutetium Mixed Perovskite crystals, like other perovskite materials (LuAP, YAP), are shorter than LSO. In addition the energy resolution values of these crystals are also of a more advantageous value for use as a scintillator material when compared with those for LSO.
[0069] It should also be noted that the higher density and stopping power of the described Lutetium Mixed Perovskite crystals provide these materials with a significant advantage in their use as a crystal scintillator when compared to the typical values associated with both YAP and LuYAP.
[0070] The aforementioned crystal scintillators can be readily modified to form a scintillator detector. This is achieved by simply optically coupling one or more of the crystal scintillators to a photodetector. The photodetector then provides an output electrical voltage in response to the secondary photons produced within the crystal scintillators themselves created in response to the absorption of the incident gamma rays, x-rays or high energy particles. A wide variety of photodetectors may be employed and a variety of coupling methods used, as is well known in the art.
[0071] In an alternative embodiment the scintillator detector may comprise one or more crystal scintillators, as described above, and one or more crystal scintillators as taught in the Prior Art. All of these crystal scintillators are then coupled to one or more photodetectors, as described previously.
[0072] The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention herein intended. | A single crystal scintillator with perovskite structure is described. The crystal is formed by crystallisation from the liquid and has the composition
Ce x Lu (1−x−z) A z Al (1−y) B y O 3
where A is one or more of the elements selected from the group comprising Y, Sc, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, In, and Ga; and B is one or more of the following elements selected from the group comprising: Sc and Ga. The crystal scintillator exhibits a high density and a good scintillation response to gamma radiation. | 2 |
FIELD OF INVENTION
[0001] The present invention relates to a system for producing L-homophenylalanine and a process for producing L-homophenylalanine using the system.
BACKGROUND ART
[0002] L-homophenylalanine ((S)-2-amino-4-phenylbutanoic acid) is extensively used in the pharmaceutical industry as a precursor for production of angiotensin-converting enzyme (ACE) inhibitors, which possess significant clinical application in the management of hypertension and congestive heart failure. Virtually all ACE inhibitors with therapeutic significance such as enalapril, delapril, lisinopril, quinapril, ramipril, trandolapril, cilazapril and benzapril, refer to L-homophenylalanine as a common building block, due to the presence of L-homophenylalanine moiety as the central pharmacophore unit.
[0003] Chemical or biocatalytic route for L-homopheylalanine synthesis have been reported in various prior art documents. U.S. Pat. No. 6,146,859 discloses a process for producing L-homophenylalanine by reacting 2-oxo-4-pheylbutanoic acid with L-glutamic acid in the presence of tyrosine aminotransferase, and subsequently precipitating the L-homophenylalanine produced therefrom. However, the process requires genetically engineered tyrosine aminotransferase as the catalytic enzyme, and high concentration of substrates.
[0004] Typical of prior techniques for producing L-homophenylalanine is the method disclosed by Bradshaw et al., Bioorganic Chemistry, 1991, 19:29. Bradshaw reported a method of converting 2-oxo-4-phenylbutanoic acid to L-homophenylalanine by using L-phenylalanine dehydrogenase in the presence of cofactor. However, the authors reported the use of conventional dialysis bag for the laboratory-scaled L-homophenylalanine production. It was found that this process has low scale-up potential besides bearing several constraints in controlling the reaction conditions for optimum synthesis of product.
[0005] Senuma et al., Applied Biochemistry and Biotechnology, 1989, 22:141 reported a method of preparing L-homophenylalanine by converting 2-oxo-4-phenylbutanoic acid using microbial cells containing aminotransferase activity. Cho et al., Biotechnology and Bioengineering, 2003, 83:226 also synthesized the compound using a recombinant aromatic amino acid transaminase in the reaction media which permits efficient synthesis of L-homophenylalanine using a single transaminase reaction. Nevertheless, the aminotransferase activity is markedly inhibited by a high concentration of substrate in the reaction mixture leading to limitations in large-scale production.
[0006] Kao et al., Journal of Biotechnology, 2008, 134:231 are principally concerned with the production of L-homophenylalanine using recombinant Escherichia coli cells with dihydropyrimidinase and L-N-carbamoylase activities as whole cell biocatalysts. However, it was found that dihydropyrimidinase exhibited non-enantiospecificity for D,L-homophenylalanylhydantoin substrate, which needs to be improved in order to improve the yield of L-homophenylalanine.
[0007] Production of L-homophenylalanine as novel pharmaceutical intermediate has been studied for many years, as disclosed in the previous section, generating substantial literature and knowledge. Presently, laboratory bioreactors are used for the production of pharmaceutical drug precursors. Conventional laboratory bioreactors require separate and often complicated downstream processing for recovery or retention of isolated enzymes from the aqueous media.
[0008] It is clear from a review of the prior art processes for production of L-homophenylalanine that a hiatus exists with respect to techniques for in situ retention of biocatalysts when present in the reaction solution. While L-homophenylalanine has been produced either by selective retention of the biocatalysts in a dialysis bag or via a separate unit connected to the bioreactor system, in-situ configuration has not been implemented for L-homophenylalanine production, thus establishing the novelty of this invention.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention provides an integrated membrane bioreactor device with an acidification vessel system for producing L-homophenylalanine, the system includes (a) a vessel having an upper surface, lower surface and a plurality of side surfaces, said upper, lower, and side surfaces defining an interior body of said vessel, (b) a membrane holder and mesh for supporting a membrane at the lower surface of said vessel, (c) a port means for introduction of substrate, aqueous solution and cofactor into and removal from said interior body of said vessel, (d) a port means for introduction of at least a biocatalyst into said interior body of said vessel, (e) a means for introduction of an inert gas into said interior body of said vessel, (f) a reactor pressure transducer and a relief valve to control pressure in the vessel, (g) an outer jacket which surrounds said vessel for heating of fluid, (h) a means for monitoring and control of pH and temperature of solution in said vessel, (i) a port means for caustic dosing, (j) a stirrer, wherein the stirrer includes a driveshaft with a drive unit and impeller blades which are mounted on the shaft, (k) a vessel having an upper surface, lower surface and a plurality of side surfaces, said upper, lower, and side surfaces defining an interior body of said vessel, (l) a port means for introduction of a fluid from the vessel into said interior body of said vessel, (m) an outer jacket which surrounds said vessel for cooling of said fluid, (n) a means for monitoring and control of pH and temperature of solution in said vessel, (o) a port means for acid dosing and (p) a stirrer for agitation of reaction solution contained within said vessel.
[0010] Furthermore, the present invention also provides a process for producing L-homophenylalanine using the integrated membrane bioreactor device with an acidification vessel system, the process includes the steps of (a) dissolving 2-oxo-4-phenylbutanoic acid, 1,4-dithiothreitol, sodium formate and NADH in deionized water at a pH of between 6 to 10 with an addition of a hydroxide, (b) adding L-phenylalanine dehydrogenase and formate dehydrogenase into a solution obtained from step (a), (c) stirring a solution obtained from step (b) at a temperature of between 27° C. to 50° C. in an inert atmosphere, (d) separating and collecting of biocatalysts from a solution obtained from step (c), (e) acidifying a solution obtained from step (d), (f) filtering white precipitate obtained from step (e), (g) washing the white precipitate from step (f) with a non-reacting liquid and (h) drying the white precipitate from step (g).
[0011] The present invention consists of several novel features and a combination of parts hereinafter fully described and illustrated in the accompanying description and the drawings, it being understood that various changes in the details may be made without departing from the scope of the invention or sacrificing any of the advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention will be fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, wherein:
[0013] FIG. 1 is a simplified schematic flow diagram of the integrated membrane bioreactor system for simultaneous reaction and retention of biocatalysts coupled to an acidification device for L-homophenylalanine production;
[0014] FIG. 2 is a schematic showing the synthesis of L-homophenylalanine (Compound 2) from 2-oxo-4-phenylbutanoic acid (Compound 1) catalyzed by L-phenylalanine dehydrogenase coupled to NADH regeneration catalyzed by formate dehydrogenase; and
[0015] FIG. 3 is a HPLC graph, showing a measurement of the enantiomeric excess of the enzymatically synthesized L-homophenylalanine using Chiral T column.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The present invention relates to a system for producing L-homophenylalanine and a process for producing L-homophenylalanine using the system. Hereinafter, this specification will describe the present invention according to the preferred embodiments of the present invention. However, it is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications and equivalents without departing from the scope of the appended claims.
[0017] Generally, the present invention relates to a system ( 10 ) and a process for the production of L-homophenylalanine, in a reaction solution which occurs in a novel membrane bioreactor for simultaneous reaction and retention of biocatalysts. More particularly, the invention refers to an integrated membrane bioreactor for in situ reaction and selective retention of L-phenylalanine dehydrogenase and formate dehydrogenase for reuse, coupled to online control of pH and temperature to provide the optimal reaction condition for higher product yield. For this invention, the substrates, enzymes and coenzymes were pumped into the system ( 10 ) with inert atmosphere. The membrane bioreactor is incorporated with an ultrafiltration membrane with the appropriate molecular weight cutoff. Sufficient time was allowed for reaction to occur, and the product leaving the membrane bioreactor was subsequently acidified. The resulting white precipitate was collected, washed and dried in vacuum to yield L-homophenylalanine without further purification.
[0018] The present invention relates to a system ( 10 ) and a process for the production of L-homophenylalanine by reacting 2-oxo-4-phenylbutanoic acid with 1,4-dithiothreitol and sodium formate in the presence of L-phenylalanine dehydrogenase, formate dehydrogenase and NADH cofactor in a reaction solution which occurs in a novel membrane bioreactor for simultaneous reaction and retention of biocatalysts. The invention relates to a system for in situ reaction and selective retention of L-phenylalanine dehydrogenase and formate dehydrogenase for reuse, also referred to as integrated membrane bioreactor.
[0019] The present invention makes use of a reactor module, coupled to an in situ separation unit for the continuous removal of products while retaining the biocatalysts. Membrane unit operations usually work under mild conditions and are environmental safe processes, as depicted in the synthesis of various pharmaceutical drug intermediates with low working temperature and pressure, with the additional advantage of minimum diffusional resistance due to direct contact between substrate and biocatalysts. For this invention, the substrates and the coenzyme were pumped into the membrane bioreactor, with the product leaving the membrane bioreactor unit through an ultrafiltration membrane with varying molecular weight cutoff for different enzymes. Enzymes are to be supplemented periodically dependent on the deactivation rates to the membrane bioreactor.
[0020] The system ( 10 ) of the invention comprises an integrated membrane bioreactor in which the reaction and separation of biocatalysts takes place, and in which the conditions and environment necessary for the reaction may be strictly controlled in an enclosed system, and a stirred reactor vessel for acidification of the product. The integrated membrane bioreactor serves as both reaction and separation vessel, thus invalidating the need for separate vessels for each function. A presently preferred embodiment of the current invention is provided in FIG. 1 in which the system ( 10 ) including an integrated membrane bioreactor device with an acidification device which produces L-homophenylalanine is described.
[0021] Hence, in a first embodiment of the present invention, there is provided the membrane bioreactor device for producing L-homophenylalanine. The device includes a first vessel ( 12 ) having an upper surface, lower surface and a plurality of side surfaces, said upper, lower, and side surfaces defining an interior body of said vessel ( 12 ), a membrane holder and mesh for supporting a membrane ( 14 ) at the lower surface of said vessel, a port means ( 11 ) for introduction of substrate, aqueous solution and cofactor into and removal from said interior body of said first vessel ( 12 ), a port means ( 13 ) for introduction of at least a biocatalyst into said interior body of said vessel, a means for introduction of an inert gas ( 15 ) into said interior body of said vessel, a reactor pressure transducer and a relief valve to control pressure in the vessel, an outer jacket ( 19 ) which surrounds said first vessel ( 12 ) for heating of fluid, means for monitoring and control of pH ( 16 ) and temperature ( 17 ) of solution in said first vessel ( 12 ), a port means ( 18 ) for caustic dosing and a stirrer ( 20 ), wherein the stirrer ( 20 ) includes a driveshaft with a drive unit and impeller blades which are mounted on the shaft.
[0022] In a second embodiment of the present invention, there is provided a device for acidifying and cooling of solution to produce L-homophenylalanine, the device includes a second vessel ( 22 ) having an upper surface, lower surface and a plurality of side surfaces, said upper, lower, and side surfaces defining an interior body of said second vessel ( 22 ), a port means ( 21 ) for introduction of a fluid from the first vessel ( 12 ) into said interior body of said second vessel ( 22 ), an outer jacket ( 23 ) which surrounds said second vessel ( 22 ) for cooling of said fluid, means for monitoring and control of pH ( 24 ) and temperature ( 25 ) of solution in said second vessel ( 22 ), a port means ( 26 ) for acid dosing and a stirrer ( 28 ) for agitation of reaction solution contained within said second vessel ( 22 ).
[0023] In a presently preferred embodiment of the current invention, both vessels ( 12 , 22 ) are borosilicate glass cylindrical vessel. However, it may be appreciated that a tank of any suitable shape and any suitable material may be incorporated into the system of the present invention.
[0024] The membrane holder is a loop of elastomer with a disc-shaped cross-section, designed to be seated in the groove at the lower surface of said vessel, preferably holding a stainless steel mesh to support the membrane ( 14 ). However, it may be appreciated that any design of membrane holder, a perforated or mesh screen of metal or any other suitable material currently used in the art, is envisioned in the design of the current invention.
[0025] Suitable reaction conditions for production of L-homophenylalanine, e.g., temperature, pH, concentration of biocatalysts and etc. are known in the art, but may vary in accordance with the particular drug precursor to be produced. Accordingly, it should be appreciated that the design of the present invention allows the condition of the reaction solution in both vessels to be monitored and suitably altered for controlling temperature, pH and the like, thus alleviating problem of unsteady state caused by manual regulation of reaction conditions. The system of the invention may also be equipped with one or more sampling ports for monitoring of the enzymatic process.
[0026] Advantages provided by the system described in the present invention include, but are not limited to:
1) Applicability to a wide range of substrates and biocatalysts; 2) Applicability to produce a wide range of drug precursors; 3) Ability to use said system for in situ reaction and retention of biocatalysts with reduction in moving parts and consequent ease of operation and reduction in capital and operating costs; 4) Use as multi-purpose vessel, including as a reactor or separation vessel; 5) Ability to monitor and control parameters (e.g. temperature by heating or cooling jacket and pH via automated caustic and acid dosing)
[0032] The process of producing L-homophenylalanine will now be described in detail with references to FIGS. 2 and 3 .
[0033] As shown in FIG. 2 , the process is preferably conducted in a reaction mixture containing 2-oxo-4-phenylbutanoic acid, 1,4-dithiothreitol, sodium formate, formate dehydrogenase, NADH and L-phenylalanine dehydrogenase in deionized water. The foremost step comprises of dissolving 2-oxo-4-phenylbutanoic acid in deionized water containing 1,4-dithiothreitol, sodium formate and NADH at a pH of between 6 to 10. The reaction was initiated by adding L-phenylalanine dehydrogenase and formate dehydrogenase. The solution was stirred at appropriate temperature of between 27° C. to 50° C. and in an inert atmosphere with the addition of 1N ammonium hydroxide to maintain the pH at a constant value.
[0034] The reaction is carried out in a 1 L membrane bioreactor over a period of 1 week. The membrane bioreactor was equipped with an overhead stirrer, pH electrode connected to the data acquisition system, heating jacket, ports for caustic dosing and internal temperature monitoring using temperature sensor. The pH of the reaction solution was constantly monitored, and the system was connected directly to automated caustic dosing system to maintain the pH at optimum value. The same procedure as the above stated was applied in the case where varying solution temperature was achieved via heating using heating jacket. The internal atmosphere was kept inert with argon gas. A flat sheet regenerated cellulose membrane with adequate molecular weight cutoff was incorporated for in situ separation and retention of biocatalysts.
[0035] Upon completion of biotransformation and retention of the biocatalysts in the membrane bioreactor, the product enriched solution was acidified, preferably to pH 5.5 in the acidification vessel. The resulting white precipitate was collected by filtration, washed with cold water and dried in vacuum to yield L-homophenylalanine without further purification (>80% depending on the solution pH, temperature, amount of biocatalysts used, etc.).
[0036] The enantiomeric excess of L-homophenylalanine is ascertained using a chiral T column that shows an enantiomeric excess of over 99%. The chromatography is preferably carried out under the following conditions: Column, Astec Chirobiotic T; Flow rate, 1 ml/min; Eluents, ethanol/water=10/90 (v/v); and detector UV 210 nm. As shown in FIG. 3 , the synthesized L-homophenylalanine had a retention time of 7.34 min, where no D-antipode could be observed. The product is optically pure as determined by optical rotation and compared to an authentic sample and literature values [α] D 20 =+48° (c1, 1N HCl). | The present invention relates to a system ( 10 ) for producing L-homophenylalanine and a process for producing L-homophenylalanine using the system ( 10 ). The system ( 10 ) and the process include monitoring and controlling of the reaction conditions (e.g., temperature and pH) to desired or predetermined values. The monitoring, adjusting and agitating steps provided by the method thereby result in a more complete conversion of the available substrate and produce a sufficient yield of homophenylalanine. | 1 |
FIELD OF THE INVENTION
This invention relates to an inflatable display screen easily collapsible for storage and/or transport and used in conjunction with electronic processing devices and more particularly to thin film transistors, portable computers, portable industrial controllers, LCD, TV screens, plasma displays, or the like.
DESCRIPTION OF THE PRIOR ART
The range of portable electronic information processing devices of most interest herein encompasses those broad families of computers, calculators, and data processor-based controllers which are readily transportable by individuals and usable on location. Such devices are usually self contained, and are commonly and descriptively known by numerous names, for example, notebook computers, lap-top computers, hand-held computers, pocket computers, portable microcomputers, portable industrial controllers, pocket calculators. These devices are sometimes collectively referred to herein merely as "portable computers". However, when the term "portable computer" is used, the entire range of portable electronic information processing devices is intended.
The problem particularly addressed herein arises from the small size of these portable computers or the like, which necessarily must be such that an individual may both comfortably transport the computer and comfortably operate the computer in temporary or remote locations, including on his or her lap or in his or her hand while, for example, traveling in an airplane or in a car. By the same token, since they are handily transportable, such portable computers ordinarily when not in use are either disposed for protection within a carrying case, or folded down upon themselves to form a protective carrying case. Thus, because of the requirements of portability, the display screens utilized in conjunction with such portable computers or the like are dimensionally quite small, which size constitutes a substantial limitation and is in multiple respects disadvantageous.
One such disadvantage is, of course, one of visibility itself, for below a certain character size, the individual using the computer must strain to see the information displayed on the screen. Concomitantly, the amount of such information displayed at any one time must necessarily be limited, and is frequently less than that available on the cathode ray tube (CRT) display of a desktop computer, for example. Yet another related disadvantage of present portable computers is that many software programs designed to run on personal, desktop, or home computers often cannot function on portable computers because their menus and screen displays are not compatible with the smaller capacity portable computer displays.
This set of difficulties will likely become more severe in the future, when it will probably be deemed desirable to further reduce the traveling size of display screens in general, and more particularly of portable computers. However, the size of the display screen cannot practically become smaller. Therefore, screen size is destined to become a primary factor in limiting appreciable further reduction in the size of portable computers. In contrast, portable computers having large display screens using large, easily readable characters would be significantly advantageous for many uses, including word processing, spread sheet operations, graphics operations and program writing. That is, while the computer shrinks, a way must be found to at least keep the display screen the same, previous size, or preferably, increase its usable information display area.
U.S. Pat. No. 5,220,521 to Kikinis, which is herein incorporated by reference, discloses a flexible keyboard for computers which can be used in combination with the screens of the present invention.
U.S. Pat. No. 5,105,186 to May et al, which is herein incorporated by reference, discloses an LCD touch screen having a viewing surface through which light passes into and out of the display and a back surface comprising a transflector such as a transflective film. Keys are displayed on the viewing surface opposite light dependent resistors in the array to indicate the viewing surface must be touched to actuate a key.
U.S. Pat. Nos. 5,804,773; 5,717,433; 5,708,160 and 5,105,186, all of which are incorporated herein by reference disclose touch screens and circuitry which can be used in the preparation of inflatable and collapsible screens of the invention.
It is to be understood that the term "active matrix" as used herein relates to a display bearing or exhibiting means such as a liquid crystal display, plasma display, field emission display and the like.
SUMMARY OF THE INVENTION
Generally, the invention provides an inflatable and collapsible display screen whereby the screen forms the active matrix or that an active matrix is used in combination with the inflatable and collapsible screen.
The display screen is for use with electronic devices either as a display such as for a computer, or as a control, such as in the form of a touch screen.
In accordance with one embodiment of the invention, there is provided a portable computer device comprising an inflatable and collapsible display screen mechanically and electrically connected to an electronic activation means capable of generating a controlled electronic signal to provide a display on the screen. Specifically, it relates to flexible inflatable display screens which are formed of one or more segments which may be so arranged to provide a substantial area for display and which may be deflated and collapsed in a compact mode for storage and travel. Thus, a display screen can provide a display area larger than the length and width of the portable device yet when deflated and collapsed can be stored for traveling within a space consistent with the dimension of such device. The screen itself can be the active matrix or an active matrix can be placed on the screen.
The electronic activation means is preferably selected from the group consisting of liquid crystal displays, active matrix displays, plasma displays and field emission displays.
In a preferred embodiment, such inflatable screens in combination with a flexible and inflatable roll-up electronic keyboard can provide when each is deflated and collapsed an even smaller device for storage and travel.
Preferably, segmented inflatable screens are bound to each other by silicone or other plastic tape and the display screens are provided with edge connectors terminating at each of the circuit patterns which are connected to a central processing unit containing microprocessors and/or other support circuitry having suitable connection to the portable computer device.
The screens can be self-standing or connected to an electronic device by means of fasteners.
It is, therefore, an object of the invention to provide an inflatable and collapsible display screen for use with electronic devices for efficient storage and/or transport.
It is another object of the invention to provide an inflatable and collapsible display screen for use with a portable computer which has the same display area while being readily collapsible into a smaller storage and transport mode.
It is a further object of this invention to provide an inflatable and collapsible display screen in combination with a flexible and inflatable keyboard which would yield an even smaller device for storage and/or transport.
It is yet another object of this invention to provide segmented display screens which show a unified image in all or some of the segmented display screens or provide separate distinct images in each of the said display screens.
A still further object of this invention is to provide a lightweight foldable display screen made of inexpensive and lightweight material which need only to be inflated to furnish a screen area of approximately the size of conventional and comparable screens.
Other objects and advantages of the invention will become more clearly understood from the drawings and the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from the front of a portable computer utilizing one embodiment of the inflatable and collapsible segmented display screen of the present invention, shown with a plurality of segments arranged in the predetermined array.
FIG. 2 is a perspective view from the front of the portable computer shown in FIG. 1 showing the mechanical and electrical connections between the segmented display screen and the central processing unit.
FIG. 3 is a perspective view from the front of an inflatable and collapsible segmented display screen of this invention in a free standing embodiment.
FIG. 4 is a perspective view showing the back view of the display screen of FIG. 1 showing various configurations of internal baffles in phantom.
FIG. 5 is a perspective view of the inflatable segmented screen of FIG. 2 showing rearwardly articulating segments of two abuttably adjacent segments.
FIG. 6 is a perspective view of touch screen in accordance with the invention.
FIG. 7 is a perspective view of an inflatable screen with an active matrix.
FIG. 8 shows a free-standing display screen embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is made to FIGS. 1 through 5 which depict various aspects of the same combination of a portable computer and the inflatable and collapsible display screen. Referring specifically to FIG. 1, the combination of a portable computer 10 comprising display screen 20 and central processing unit 30 utilizes one embodiment of the present invention. Segmented display screen 20 comprises a plurality of segments 21, 22, 23 and 24 abuttably disposed in a predetermined array for use, which screen is inflatable and collapsible and which segments are rearrangeable in compact relation for storage. Portable computer 10 typically may include a central processing unit 30 including a keyboard 31 or other manual input means, a data processing unit (not shown), memory means (not shown), a power source (also not shown) and screen adjusting means 32. Each display screen segment has disposed therein an electronically activated display means, such display means being shown as items 25, 26, 27 and 28.
FIG. 2 is a rear view of FIG. 1 and shows the same combination of a portable computer 10, comprising an inflatable and collapsible segmented screen 20 as shown in FIG. 1 and also shows generally the means which provide the necessary mechanical and electrical connections which permit the display screen segments to be abuttably arranged in side-by-side relation in a predetermined array for use, while permitting the segments to be disarranged from the array and rearranged into compact relation for storage and/or transport. Additionally shown are means for providing mechanical and electrical connections between the display screen 20 and the electronic keyboard 31.
With reference to FIG. 2, these connections means will be described in detail. In one preferred embodiment, the display screen 20 of the present invention which includes appendage 29 which is designed to be inserted into slot 35. The display screen 10 may be inflated before or after insertion into slot 35. Such inflation may be performed either by a pressurized means or by lung power. The display screen 20 may include an inflatable hose (not shown). After insertion of the display screen 20 into slot 35 of the central processing unit 30, pivoting latch assemblies 33, which are contained within the housing of central processing unit 30, lock the display screen 20 into place. By means of extremely thin lead connections, the various segments of the display screen 20 are connected to the central processing unit 30. The lead connections are so thin that in practice they will not be seen and therefore will not interfere with the visual quality of the image in the display screen. In other respects, the wiring arrangement will be known to a person skilled in the art, so that a more detailed description is not necessary. The central processing unit 30 is energized by power inlet 33.
Both the electrical and mechanical connection means can be carried by either the back of a segment or by at least one side thereof. The mechanical connection means 32 can be either articularly constructed or be disengageable. Likewise, electrical connection means can be disengageable.
It is contemplated that in the most usual embodiment, the electrically activated display means carried by each segment will be planar in form and that when the plurality of segments is assembled in a desired array all the aforementioned means will lie in the same plane. However, it will be understood as being within the scope of this invention that some or all of the display means may be concave or convex. Even when the display means are each individually planar, it is within the scope of this invention that some of the display screen may be angularly extended toward the user.
An arrangement wherein the display device 20 shown in FIGS. 1 and 2 is connected to an electronic activation means by way of the programmable computer located within the central processing unit 30 using keyboard 31 for writing and entering of the desired text, and to a screen 20 for simultaneous display of the written text which is to be displayed by means of the device according to the invention. Alternatively, the signals may be generated remotely and fed through electrical conductor 34 from a distant source.
The inflatable and collapsible segmented display screen as illustrated in FIGS. 1 through 5 can be formed from at least two sheets of nonconductive, flexible, and resilient materials such as plastics. These segmented sections 21, 21b, 22, 22b, 23, 23b, 24 and 24b may be formed from sheets of thermoplastic or thermosetting nonconductive, flexible and resilient polymers, including polyesters, polyolefins such as polypropylene, polyethylene, polysilicones, polyvinyl chloride and polyurethanes. Preferably, the film sheets are joined by fusion bonding to form a hermetical seal. The hermetical seal also provides some structural rigidity to the display screen. However, other conventional bonding methods may be used such as adhesive bonding or ultrasonic sealing.
While FIGS. 1, 2, 3 and 4 essentially show triangular shapes for the display screen, it is within the scope of this invention to incorporate various shapes for this component. In fact, any geometrical configuration could be used in the design of the display screen.
Optionally, septae or baffles 41 which are two or three dimensional can be included within the gas compartment of the display screen as shown in FIG. 3. The baffles provide structural support to the fluid envelope but do not interfere with the movement of the fluid. The baffles also provide protection against overinflation and maintain proper size and shape. The baffles may be affixed to the inner portion of the sheet of the fluid envelope, e.g. by adhesives, melt welding or by ultrasonic methods. FIGS. 4 and 5 show a variety of orientation and shapes of the baffles 41 in the free-standing display screen embodiment of FIG. 3 and FIG. 8.
Referring to FIG. 3, when the screen 20 is deflated, segments 21, 22, 23 and 24 may be rearwardly articulated for storage or transport. For example, segments 22 and 24 may be folded over segments 21 and 23. The assembly may be folded in compact fashion for storage and/or transport.
FIG. 6 illustrates a touch screen 50 comprising an inflatable support 51 having a liquid crystal display 53 through which light passes into and out of the display. The back surface of the display 53 comprises a transflector (not shown) for reflecting some of the light back through the display. A keyboard 52 is provided wherein a key is actuated by the viewing surface and limiting the light transmitted to light detecting means (not shown). The circuitry and keyboard interface is described in U.S. Pat. No. 5,105,186, which is herein incorporated by reference.
FIG. 7 illustrates a free standing screen 60 of the invention which comprises an inflatable support and a bottom support 61 having baffles. The support 61 has a separate area for inflation preferably by use of a liquid so as to provide a firm stand. The screen 60 has an active display portion 63 which is not segmented. The interior of support and on the back of the display portion 63 are the electrical connectors. The screen 60 can be used in connection with a standard size keyboard.
While the drawings and specification have described the invention with reference to portable computers, it will be understood by those skilled in the art that the invention may have applications with stationary type computers as well.
In the drawings and specification there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation, the scope of the invention being set forth in the following claims. | An inflatable and collapsible display screen for electronic devices such as portable computers, TV screens, LCD and the like, which provides a screen area of approximately the size of conventional and comparable portable computer monitor screens, and the like. Upon deflation, the display screen may be folded into a small package for storage and/or transport. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a child support seat and cushion; more particularly the invention relates to a support seat and cushion useful for supporting small infants in an upright, seated position. The invention itself is particularly adapted for placement on a floor or other relatively flat support surface.
An infant support seat should provide a relatively soft seat cushion and support along a backrest, as well as support on either side of the backrest, because very small infants are unable to remain seated in an upright position without such support. In addition, the support seat should have a restraining belt or similar attachment which is adjustable to prevent the infant from falling forward out of the seat. If the infant support seat is intended for a particular application, as for example a support seat for use in a vehicle, there must be a mechanical attachment for securing the support seat to the vehicle.
The present invention is not intended for use in a vehicle but is primarily intended for supporting an infant in a seated position on a floor or similar flat surface. In this application it is a principal object to provide a safe and secure infant seat which will permit the infant's custodian an opportunity to engage in other activities, i.e. household activities, while keeping the infant under observation but without the need to physically hold the infant at all times. An advantage of the present invention is that it accomplishes this object while providing pleasant diversions for the infant's attention and stimulating the infant to perform various tactile exercises.
another object and advantage of the present invention is to provide a stable seating arrangement which will not tip over on its side when the infant is confined therein.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a formed and molded seat and backrest affixed to an enlarged flat support base which extends outwardly beyond the seat and backrest. This is removably inserted into an assembly comprising a padded cushion seat, side support cushions, and backrest cushion which assembly has an openable pocket for receiving the molded seat and backrest. The side support cushions each have toy-like attachments affixed thereto, and the entire cushion assembly may be shaped and configured as an animal body or in some other cartoon image which is pleasing to infants. The backrest cushion has a rear pocket for holding articles which cannot be reached by the infant, and a padded restraining harness is provided for adjustably confining the infant in the support seat.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention is described in the specification and claims herein, and with reference to the drawings, in which:
FIG. 1 shows an isometric view of the molded seat and support base of the invention;
FIG. 2 shows an isometric view of the padded cushion assembly of the invention;
FIG. 3 shows the cushion sections in a flat layout position;
FIG. 4 shows a bottom view of the invention; and
FIG. 5 shows a cross section view taken along the lines 5--5 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, the molded seat and support base of the invention is shown in isometric view. The molded seat and backrest 12 is preferably about 12-18 inches in height with side support walls 13 being curved to conform about the infant in a seated position. The side support walls 13 may be any desirable height and should be spaced apart a sufficient distance to allow for the cushion members and the infant's body. The molded seat and backrest 12 are affixed to a flat base support member 14 which extends outwardly beyond the seat and backrest on all sides. The base support member 14 and the seat and backrest may be formed from a single molded part or may be separately formed and later affixed together. These members may be made from plastic or fiberglass material or other similar material.
FIG. 2 shows an isometric view of the cushion assembly 10 in an embodiment which is formed into a cartoon rabbit configuration by way of example, and not by way of limitation. It is apparent that the particular cartoon image selected for the cushion assembly 10 is limited only by the imagination of the designer. Cushion assembly 10 is formed from a number of cushion sections which are best identified with reference to FIG. 2 and FIG. 3. Each of these cushion sections are preferably made from a double-layer cloth material having an interior pocket for holding and confining a suitable pad, as for example a cotton or plastic foam material having a resilient cushion feel, which is compressible and which tends to return to an original cushion form. A backrest cushion section 20 may be formed with an animal or other image applied thereto, as is illustrated by the rabbit image shown in FIG. 2. In addition, the particular rabbit image shown in FIG. 2 may also have simulated rabbit ears 21, 22 as shown, which may be designed to appear as floppy appendages affixed to an edge of cushion section 20.
A left support cushion section 24 is constructed with an inner cushion layer 24a and an outer cushion layer 24b, each of said inner and outer layers having a two-panel cloth material enclosing an interior pad. Right support cushion 26 is similarly constructed with an inner cushion layer 26a and an outer cushion layer 26b, each of said inner and outer layers having a two-panel cloth material enclosing an interior pad. Left support cushion layer 24a is affixed to backrest cushion section 20 along a seam 25, and right support cushion layer 26a is affixed to backrest cushion section 20 along a seam 27. A simulated arm or leg 23 may be affixed to left support cushion section 24, and a simulated arm or leg 28 may be affixed to right support cushion section 26, as shown in FIG. 2. Each of these members may be made from a cloth material which is graspable by an infant seated in the support seat.
A seat cushion section 30 is similarly constructed of a two-panel cloth material enclosing an interior pad. Seat cushion section 30 is affixed to backrest cushion section 20 along a seam 18 and is affixed to left support cushion layer 24a along a seam 31 and is affixed to right support cushion layer 26a along a seam 29. In the flat layout view of FIG. 3, seams 29 and 31 are shown separated for clarity in showing the flat layout; but it should be understood that the respective cushion sections are joined together by these seams in the actual construction.
A padded crotch support 32 is affixed to seat cushion section 30 along a seam 33. Crotch support 32 has a belt sleeve 34 affixed at its distal end, and belt sleeve 34 is sized to receive the respective ends of a restraining belt 16. Restraining belt 16 has a conventional buckle arrangement and is adjustable to accommodate various sizes of infants. The buckles of restraining belt 16 may be connected inside sleeve 34; and therefore, the buckles cannot be disconnected by an infant seated in the seat.
FIG. 4 shows a bottom view of the invention, wherein a release mechanism 40, such as a zipper or Velcro fastener, is arranged along the rear edge of the outside cover 38. Release mechanism 40 may be opened to permit the seat 12 and base support member 14 to be installed and removed from the inside of the cushions.
FIG. 5 shows a cross-section view taken along the lines 5--5 of FIG. 4. This view illustrates the interior pocket which is created to confine the molded seat and backrest 12 and base support member 14 inside the various cushion sections. This view also illustrates how left support cushion section 24 is formed into an inner layer 24a and an outer layer 24b. Likewise, right support cushion section 26 is formed into an inner layer 26a and an outer layer 26b. The respective inner layers 24a and 26a are affixed to seat cushion section 30 along seams 29 and 31, and the respective outer layers 24b and 26b are affixed to outer cover 38 along seams 41 and 42. Backrest cushion section 20 does not have a comparable inner and outer cushion layer but is defined by an inner cushion section 20 which is affixed to outer cover 38 along its upper edge seam 19. A pocket (not shown) may be added to the outside of outer cover 38 in the area behind the backrest 12.
In operation, the molded seat and backrest 12 and the base support member 14 may be inserted into the cushion assembly 10 by opening the release mechanism 40 which reveals the interior pockets sized to receive these parts. The molded seat and backrest and the base support member are positioned inside the respective pockets as shown, and the release mechanism is fastened to hold these parts inside the cushion assembly 10. The procedure is reversed to remove the molded seat and backrest 12 and the base support member 14. The infant may be seated into the cushion assembly 10 between the armrests and the crotch support 32 may be brought up between the infant's legs, and the restraining belt 16 may be fastened. The restraining belt buckles are moved inside the sleeve 34, and the apparatus is ready for use.
The foregoing description of a preferred embodiment of the invention is illustrative of a preferred construction and is not intended to be limiting of the scope of the invention; it is desired that the scope of the invention be limited solely by the claims appended hereto. | An infant support seat and cushion having an inner support structure including a backrest and seat and base support member and having a removable cushion assembly. The cushion assembly has a back cushion section, a seat cushion section and a pair of side support sections. An outer cover is attached to the cushion assembly and has a release mechanism to permit the insertion and removal of the inner support structure relative to the cushion assembly. A crotch support strap and detachable belt sections hold the infant in the cushion assembly in use. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to co-pending U.S. provisional application 60/563,716, filed Apr. 20, 2004. The provisional application is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention concerns headphones and related circuits, accessories, and methods.
BACKGROUND
[0003] Headphones are used in variety of applications to facilitate private listening of devices, such as stationary and portable stereos, digital video players, digital music players, computers, and so forth. Some of these headphones are equipped with automatic noise reduction (ANR) circuitry. This circuitry automatically cancels or suppresses loud persistent ambient noise within the headphones, allowing users to enjoy an electronically controlled silence or an improved listening experience.
[0004] A seminal example of ANR headphones is the Quiet Comfort™ line of headphones from Bose Corporation of Framingham, Mass. Bose recently released a new version of these headphones, Quiet Comfort 2™, which incorporates improvements, such as a fold-flat design for more space-efficient storage and integration of its ANR electronics and battery box into its earcups. (Quiet Comfort and Quiet Comfort 2 are presently believed to be trademarks of the Bose Corporation.) The new version also includes an audio input plug with a built-in audio attenuator. The audio attenuator has a high-low switch to reduce or attenuate the volume of audio signals input to the headphones. The audio input plug is coupled via an insulated multi-wire electrical cable to a standard ⅛-inch male headphone plug, which is compatible with the female audio output of most laptops, and portable video and music players.
[0005] Despite these improvements, the present inventor has recognized that the Bose Quite Comfort headphones, as well as other competing ANR headphones, are not readily adaptable for use with two-way communications devices, such as cordless or mobile telephones, or for simultaneous connection to more than one audio source. For example, the Quiet Comfort and other headphones are typically provided with a two-prong-plug adaptor for coupling the headphone plug to the audio output port typically found in commercial airliners. It is also typical to provide an adapter for coupling the ⅛-inch headphone plug to a ¼-inch stereo phone port commonly found on stationary home stereo and entertainment systems. However, none of these adapters allow use of the ANR headphones with two-way communications devices or multiple audio sources.
[0006] Accordingly, the present inventor has identified unmet needs to expand the utility and ultimately the value of ANR headphones.
SUMMARY
[0007] To address this and/or other needs, the present inventors devised one or more systems, devices, circuits, and methods for expanding the utility and value of ANR and non-ANR headphones. One exemplary device, a hands-free adapter for use with ANR headphones, includes a microphone and two stereo-type plugs electrically coupled via a cable. The first stereo-type plug connects to a hands-free jack of a mobile telephone, and the second plugs connects to the audio-input jack of the headphones. The microphone is mounted on the second plug and electrically coupled through the cable and the first plug to a microphone input portion of the hands-free jack. This arrangement allows convenient and unprecedented use of the ANR headphones with the mobile telephone.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 is a block diagram of an exemplary system 100 corresponding to one or more embodiments of the present invention.
[0009] FIG. 2 is a partial electrical schematic of system 100 , corresponding to one or more embodiments of the present invention.
[0010] FIG. 3 is a block diagram of an exemplary system 300 corresponding to one or more embodiments of the present invention.
[0011] FIG. 4 is an electrical schematic of system 300 , corresponding to one or more embodiments of the present invention.
[0012] FIG. 5 is an exemplary electrical schematic of a source selector component of system 300 , corresponding to one or more embodiments of the present invention.
[0013] FIG. 6 is a partial perspective view of an exemplary earpiece-and-connector subassembly 600 for systems 100 and 400 , which corresponds to one or more embodiments of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0014] The following detailed description, which references and incorporates the attached Figures, describes and illustrates one or more specific embodiments of the invention. These embodiments, offered not to limit but only to exemplify and teach, are shown and described in sufficient detail to enable those skilled in the art to implement or practice the invention. Thus, where appropriate to avoid obscuring the invention, the description may omit certain information known to those of skill in the art.
[0015] FIG. 1 show an exemplary system 100 corresponding to one or more embodiments of the present invention. System 100 includes ANR headphones 110 , an adapter 120 , and a communications device 130 . System 100 can be sold or offered as a complete system, as separate components, or as subcombination kits. For example, one exemplary kit includes headphones 110 and adapter 120 , and another exemplary kit includes communications device 130 and adapter 120 .
[0016] ANR headphones 110 includes earpieces 112 and 114 and a bridge member 116 . Earpieces 112 and 114 , each of which take an over-the-ear (circumaural) form in the exemplary0 embodiment, fit over or engage respective ears of a user (not shown). In some embodiments, the earpiece take on-the-ear, in-the-ear, or behind-the-ear form.
[0017] Specifically, earpiece 112 , which is mechanically connected to earpiece 114 via bridge member 116 , includes ANR circuitry 1121 , an ANR microphone 1122 , an ANR speaker 1123 , a non-ANR speaker 1124 , a battery compartment 1125 , and an audio input jack 1126 . In the exemplary embodiment, earpiece 114 is substantially identical to earpiece 112 with the exception of battery compartment 1125 and audio input jack 1126 ; thus, for sake of brevity, no further description of earpiece 114 is given. Bridge member 116 , in some embodiments, folds in half. Also in some embodiments, earpieces 112 and 114 each rotate inwardly (toward the region between the earpieces.)
[0018] ANR circuitry 1121 , which is powered for example by one or more AA or AAA batteries in battery compartment 1125 , responds to a range of low-frequency acoustic energy sensed via ANR microphone 1122 by driving ANR speaker 1123 to produce an opposing acoustic signal. The opposing acoustic signal destructively interferes with the low-frequency acoustic energy, thereby reducing its magnitude and improving the clarity of acoustic signals from non-ANR speaker 1124 . Speaker 1124 is driven via electrical signals from a right-channel contact 1126 R of audio input jack 1126 —which includes a ground contact 1126 G, a right-channel contact 1126 R, and a left-channel contact 1126 L—is coupled or couplable to adapter 120 . (In the figures, the numerical prefixes for the contacts are omitted.)
[0019] Adapter 120 includes a headphone-microphone connector 121 , a cable 122 and a device connector 123 .
[0020] Headphone-microphone connector 121 , which in the exemplary embodiment takes the form of three or four-contact male or female stereo plug connector, includes a connector housing 1211 ; a multi-contact stem or socket 1212 ; controls 1213 ; and a boom microphone assembly 1214 . Connector housing 1211 , formed by molding a durable insulative material, such as plastic, holds multi-contact stem 1212 and supports boom microphone assembly 1213 . Multi-contact stem 1212 includes a ground contact region 1212 G, a right-channel contact region 1212 R, and a left-channel contact region 1212 L, which make electrical contact with respective contacts of 1126 G, 1126 R, and 1126 L when connector 121 is properly engaged with audio input jack 126 . (The figure omits the 1212 prefix from the contact reference labels.) Controls 1214 include one or more switches, potentiometers, or other devices for muting or adjusting the volume of signals output from connector 121 to headphone 110 .
[0021] Boom microphone assembly 1213 includes an boom 1213 A and a microphone 1213 B.
[0022] Boom 1213 , which can be formed of flexible conduit, extends laterally from connector housing 1211 to support and position (or allow positioning of) microphone 1213 in a region suitable to promote sensing of audible signals from a user wearing headphones 110 equipped with adapter 120 . In some embodiments, microphone 1213 B is positioned in and/or on connector housing 1211 and boom 1213 A is a tube (or wave guide) acoustically bridging all or part of distance between microphone 1213 B and a user's mouth. (See, for example, U.S. application 20040062413, published Apr. 1, 2004, which is incorporated herein by reference.)
[0023] Microphone 1213 B, in the exemplary embodiment, includes an unbuffered electret microphone. This type of microphone is generally suitable for use with microphone preamplifiers typically found in mobile and cordless telephone phones or other devices compatible with hands-free accessories. (Some embodiments also include, within the connector housing, a battery and a high-performance preamplifier for the microphone, thereby improving audio performance over the level provided by the preamp in the communications device.) Microphone 1213 B includes positive and negative contacts (not visible in the figure), which are coupled along with the contact regions of multi-stem 1212 to one or more insulated conductors in cable 122 . (Some embodiments incorporate a Bluetooth-compatible wireless transceiver and battery within connector housing 1211 to replace cable 1222 .)
[0024] Coupled electrically to cable 1222 is device connector 122 . Device connector 122 , which in the exemplary embodiment takes the form of an ⅛-inch (2.5-millimeter) three-conductor stereo plug or socket, includes a connector housing 1221 and a multi-contact stem or socket 1222 . Connector housing 1221 , formed by molding a durable insulative material, such as plastic, holds multi-contact stem 1222 . Multi-contact stem 1222 includes a ground contact region 1222 G, a microphone contact region 1222 M, and a speaker contact region 1222 S., may use a, which make electrical contact with respective contacts of 1326 G, 1326 M, and 1326 S when connector 122 is properly engaged with hands-free jack (or connector) 132 on communications device 130 . (The figure omits the 1222 prefix from the contact reference labels.)
[0025] Communications device (or system) 130 includes, among other items, an audio output jack 122 and an external microphone jack 124 . In the exemplary embodiment, communications device 120 takes the form of a cellular or cordless telephone, with output jack 122 and microphone jack 124 coupled to interface circuitry (not shown) which supports use of a conventional hands-free mobile-phone headset, which includes a microphone and an ear-piece (or headphones). (Hands-free headsets typically include an unbuffered electret microphone that is powered by interface circuitry (not shown) in the cell phone or other type secondary device. In the exemplary embodiment, this interface circuitry is not suitable for boom microphones in aviation headsets.) In some other embodiments, device 130 takes the form of a two-way radio, laptop computer, or other audio source or audio output device, such as a music or video player or other personal listening device. In some of these embodiments, connector 122 is implemented as two separate stereo plugs or connectors for use with communications devices having separate microphone and headphone jacks.
[0026] FIG. 2 shows a partial electrical schematic of system 100 . The schematic highlights the electrical connections between headphone input jack 1126 and headphone-microphone connector (HMP) 123 and between device connector 123 and device hands-free jack 132 .
[0027] FIG. 3 shows an exemplary headphone system 400 which in addition to previously described headphones 110 and two-way communications device 130 , includes a multi-source (or device) adapter 410 and an additional communications device 420 . In addition those components already described for adapter 120 in FIG. 1 , multi-source adapter 410 includes a source selector 412 , a multi-conductor cable 414 , and a device plug 416 . Source selector 412 , which is positioned within the housing of headphone-microphone connector 1211 , is coupled via cable 122 to device connector 123 and via cable 412 to device connector 416 . Device connector 416 , which for example take the form of a 2.5 or 3.5 millimeter stereo plug connector, couples to the audio output jack of communications device 420 . Device 420 in some embodiment takes the form of a digital music or video player, such as an iPod music player or other MP3 player.
[0028] In operation, source selector 412 normally couples device connector 416 (and thus communications device 420 ) to the stem of connector 1211 and thus to the audio input jack of headphones 110 . However, when device 130 generates a microphone bias signal, for example in response to receiving a phone call and ringing, a microphone bias signal is communicated through cable 122 to selector 412 . In response, selector 412 , which functions as a break-before-make multiplexer, decouples communications device 420 from the stem of connector 1211 and couples device connector 123 and thus device 130 to stem of connector 1211 and to the audio input jack of headphones 110 .
[0029] FIG. 4 shows an exemplary electrical schematic for system 400 , which like FIG. 2 highlights connections within adapter 410 and connection of adapter 410 to headphones 110 and devices 130 and 420 .
[0030] FIG. 5 shows an exemplary implementation of source selector 412 in the form of circuit 500 . Circuit 500 includes dual SPDT (single-pole-double-throw) analog switch 510 , a low-pass RC filter 520 , and a battery 530 . One example of a suitable analog switch is part number FSA2267 from Fairchild Semiconductor of South Portland, Me. In the exemplary embodiment, batter 530 is a coin cell battery.
[0031] FIG. 6 shows a perspective view of an exemplary earpiece-and-headphone-microphone subassembly 600 , which is applicable to systems 100 and 400 . Subassembly 600 includes an earpiece 610 and a headphone-microphone connector 620 . Earpiece 610 includes an sector or pie-shaped opening 612 which provides access to a socket of an audio input jack. Connector 620 , which is shown with two cables, has a housing 622 with a sector or pie-shaped portion that is sized to mate with pie-shaped opening 612 in earpiece 610 .
CONCLUSION
[0032] The embodiments described above are intended only to illustrate and teach one or more ways of practicing or implementing the present invention, not to restrict its breadth or scope. The actual scope of the invention, which encompasses all ways of practicing or implementing the concepts of the invention, is defined by the following claims and their equivalents. | One exemplary device, a hands-free adapter for use with ANR headphones, includes a microphone and two stereo-type plugs electrically coupled via a cable. The first stereo-type plug connects to a hands-free jack of a mobile telephone, and the second plugs connects to the audio-input jack of the headphones. The microphone is mounted on the second plug and electrically coupled through the cable and the first plug to a microphone input portion of the hands-free jack. This arrangement allows convenient and unprecedented use of the ANR headphones with the mobile telephone or other suitably equipped communication devices. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
This non-provisional application claims priority to the provisional application having Ser. No. 61/030,777 filed on Feb. 22, 2008 and is commonly owned by the same inventor. This application is related to U.S. Pat. No. 6,786,362 from the same inventor.
BACKGROUND OF THE INVENTION
This invention relates generally to hopper tees used in bulk material handling, and more specifically pertains to a directional hopper tee that blends material dropping vertically therethrough with material entering and passing through horizontally. A unique aspect of this invention is a fluted vertical pipe that begins at the flange. The invention is especially useful for accelerating the unloading of a tank trailer hauling granular bulk material at higher ground clearance.
Hoppers, or tank trailers, regularly transport bulk commodities such as industrial and food products. When the hopper, or tank trailer, reaches its destination, the bulk commodity is unloaded, typically by a power take off driven truck mounted blower or a pneumatic system of a plant or factory. The bulk commodity generally unloads from the hopper and into a pipeline. To complete the unloading, hopper tees are mounted to the discharge outlet of the hoppers, or bins. The hopper tee conventionally has a vertical section of constant dimension and shape and a horizontal section also of constant dimension and shape forming the inverted T shape configuration. To transfer the bulk commodity, the material is moved out of the hopper, or bin, by gravity flow or air pressure vibration into the vertical section of the hopper tee. The clean discharge pipe is connected to the horizontal section of the tee. Pneumatic conveyance of the bulk material through the pipe occurs by establishing a pressure differential in the pipe.
The prior art hopper tees have a complete, one piece assembly that includes a vertical section, connecting to a hopper, and a horizontal section, connecting to a discharge pipe. The prior art hopper tee design fits on the bottom of the bins of pneumatic tank trailers. Typically, the valve of a bin bolts to the flange of the hopper tee. Although prior art hopper tees function well for their intended purposes, some hopper tees lack proper ground clearance for long trailers. Ground clearance has afflicted the tank trailer trucking industry for years. For example, as the hopper tee mounts the tank, ground clearance problems arise when a long trailer, such as a tank trailer, crosses railroad tracks or other uneven surfaces. The longer the trailer, the easier a hopper tee becomes stuck upon a railroad rail, berm, or other short height surface condition. A stuck trailer delays delivery of product to its destination, risks delay penalties to the trucking company, and increases recovery and repair costs of the tank trailers.
The Department of Transportation (DOT) and state highway departments have established heights, widths and lengths the tank trailers must meet. When the hauler transports light density products, such as plastic pellets, the hauler requires a larger cubic foot capacity, or volume, to haul a maximum payload and make hauling such products economically feasible. To increase the cubic foot capacity and remain within DOT height, width and length standards, the prior art and industry have dropped the bottom of the hopper. However, the bottom of the hopper requires angled walls (due to the angle of repose of the bulk material) that funnel down to the hopper tee to allow for emptying of bulk granular material. For most dry bulk products the angle of repose is approximately 45 degrees to the horizontal to obtain the maximum tank volume, in cubic feet, while remaining within the mandated dimensions.
DESCRIPTION OF THE PRIOR ART
A variety of patents have issued upon various devices to ease the transfer and unloading of bulk granular ingredients from a hopper or bin into a discharge line for delivery to a plant or factory. Prior art hopper tees have a construction of a vertical pipe welding to a horizontal pipe in a generally T shape. These tees remain subject to excessive internal wear by the friction of bulk materials and eventually fail as they wear away. Previously, the Applicant has addressed such wear problems. The U.S. Pat. No. 4,848,396 to Sisk discloses a cast hopper tee designed to provide a smooth and uninterrupted internal transitional surface. That patent also provides for such an improvement in a bottom drop hopper tee.
The U.S. Pat. to Campbell et al., U.S. Pat. No. 6,582,160 provides a hopper tee with a valve. This hopper tee has an inlet that connects to a hopper discharge opening and a perpendicular second hollow pipe section. The inlet has a cylindrical side wall, as in FIGS. 8 , 9 and the second hollow pipe section also has a cylindrical cross section as in FIGS. 3 , 10 . FIGS. 9 , 10 also show exterior tapering of the inlet and the second hollow pipe section. Unlike the present invention, the Campbell patent shows a straight sidewall at the flange, constrictions of the flow path in the second hollow pipe section as at 68 in FIG. 8 , and no arcuate flutes upon the interior of the inlet and second hollow pipe section.
The U.S. published application to Kraenzle, No. 2006/0082138 shows a dual flange tee. One flange 24 goes beneath the perimeter of a valve and the other flange has two wings 14 and 16 that secure below the complete flange 24 . Below the wings, the flange tee has a generally cylindrical lower pipe section as in FIG. 2 . The lower pipe section has a neck of little, if any, height. The connection between the upper pipe section and the lower pipe section is generally square, as in page 2 col. 21.
The U.S. Pat. No. 5,387,015 to Sisk has a single piece hopper tee with an elliptically shaped opening within the neck. Generally a first pipe with a flange joins perpendicular to an edge of a second pipe that then connects to pipeline tubing. The first pipe also has an elliptically shaped interior space and a pair of wear saddles creating double wall thicknesses at the transition areas between the vertical and horizontal pipes that resistant wear by materials sent through the tee. The first pipe has a neck at a square angle to the flange and then the neck flares outwardly upon the entire perimeter. The second pipe has a constant diameter without fluting. This patent lacks the immediate curvature along a portion of the neck, fluting within the second pipe, and single direction of flow as in the present invention.
Then the design patent, U.S. No. D376,416 to Sisk shows the physical appearance and ornamentation of a directional tee. This patent shows a round flange for connection to the hopper discharge and FIGS. 3 , 9 show part of the neck with a square angle to the flange and an opposite portion of the neck attaining a slope slightly below the flange. FIGS. 7 , 10 show slight bulging of the lower pipe below the hopper discharge with the bulging tapering towards the outlet. No interior fluting of the lower, or horizontal pipe, and no immediate curvature of the neck at the flange are shown by this patent.
The U.S. Pat. No. 5,676,404 again to Sisk, shows a low profile tee akin to Kraenzle above. Unlike Kraenzle, this patent shows a tee where the diameter of the hollow pipe section increases proximate the opening to the discharge hopper as in FIG. 2 . This patent does not show fluting in the hollow pipe section, curvature of the neck at the flange, and single direction use.
The U.S. Pat. No. 5,842,681 also to Sisk describes a pivotal hopper tee. This hopper tee has a mounting frame that connects to the hopper discharge and a camming handle with a hook that swings upon pivot arms. Beneath the mounting frame, the hopper tee has a cylindrical cross section that increases in inside diameter near the valve opening, as in the upper dashed line in FIG. 4 .
And then, the U.S. Pat. No. 6,786,362 to Sisk appears related to the '681 patent. This swing away hopper tee has a mounting frame that connects to a tee assembly. The mounting frame provides a flange that extends well beyond the diameter of the hopper tee. The hopper tee geometry is mentioned briefly in this patent but no fluting or diameter changes are shown in FIGS. 3 , 6 , 7 . FIG. 7 of the '362 patent shows a hopper tee of constant diameter and its particular lever.
The prior art has various hopper tees with a flat door, large wings extending coplanar with the door, and carriage bolts and wing nuts connecting to the wings. Over time, with rugged usage, and subject to environmental factors, the wing nuts and carriage bolts become hard to open and make the door no longer fit flush with the bottom of the horizontal pipe. The improper fit of the prior art door causes excessive wear to the bottom of the horizontal pipe, shortening its useful life. The prior art shows various hopper tees to resist the abrasion of bulk materials and to provide bottom drop capability. However, the hopper tees remain subject to industry mandated clearance requirements. One clearance requirement remains 15.25 inches between the top of the flange of the hopper tee and the ground surface and a second clearance requirement is 4.25 inches between the top of the flange of the vertical pipe and the center of a 4 inch inside diameter horizontal pipe of a hopper tee. The 4 inch diameter horizontal pipe connects readily with existing 4 inch diameter plant and factory conveying systems. A third clearance requirement of 5.5 inches from the top of the flange to the center of the inside diameter of a horizontal pipe applies to a 5 inch diameter hopper tee. A hopper tee with high ground clearances remains desirable to the bulk material hauling industry.
SUMMARY OF THE INVENTION
This invention provides a directional hopper tee with an internally fluted vertical pipe blending into a horizontal pipe. The hopper tee has a vertical pipe with an opening that connects to a hopper, or bin, to receive bulk material into the tee and a horizontal pipe centered upon one end of the vertical pipe. The horizontal pipe has an inlet that receives bulk material and pressurized air from ahead of the hopper and an opposite outlet that discharges the bulk material already flowing in the horizontal pipe and that received from the hopper through the vertical pipe. The vertical pipe has a flange that abuts the hopper and an opening in the flange that matches the opening of a valve on the hopper itself. At the opening, the vertical pipe begins to turn towards the outlet of the lower pipe with a flute. The flute begins immediately at the flange resulting in a vertical pipe with a curved shape towards the outlet and a square shape towards the inlet. The present invention raises the ground clearance of the horizontal pipe by at least one inch resulting in a hopper tee that clears at least 7 inches above the ground. The hopper tee of the invention also unloads up to and including 22% more product per minute than prior art tees during field conditions. Alternate embodiments of the present invention provide a reinforced flange, a drop tee, and a low profile drop tee. The present invention aids in the unloading of bulk materials from various truck, rail, and ship transporters.
During unloading of bulk materials through the invention, the materials contact the tee and its various parts. Such contact induces friction between the materials and the tee along with friction within the materials, that is internal friction. The rise in friction during unloading creates heat, often measured as a rise in temperature of the tee. However, the present invention using its flute lessens the friction between the tee and materials and the internal friction of the materials during the turn from the vertical pipe to the horizontal pipe. The present invention causes a temperature rise in the tee generally 10° F. to 20° F. less than prior art tees, or an unloading temperature generally 10° F. to 20° F. closer to that of the product temperature. Drivers in the field report unloading hoses being cooler to the touch than before. Limiting the unloading temperature rise becomes important for heat sensitive bulk materials where higher temperatures may cause the bulk materials, to melt or to set or to congeal, such as to become “stringers” of melted plastic pellets, before departing the tank trailer.
Further, independent testing of the device flow capacity has found the invention increases flow by approximately 300 scfm more than prior art tees, or approximately 7300 scfm, see Appendix A. The increased flow results in faster unloading at a delivery site and a quicker turnaround for a tank trailer to deliver its next load. In field tests, drivers reported that surging of product during unloading ceased during usage of the present invention. Surging through the present invention has nearly vanished for usage with HDPE pellets, glass silica sand, soda ash, and flour along with other bulk materials. Reduction in product surges leads to less instances of plugged unloading lines and the resultant downtime during an unload cycle.
In a rising or high fuel cost environment, trucking companies, drivers, and their customers seek to minimize costs at any opportunity. The prior art has sought various devices to unload bulk material from a vertical hopper into a horizontal line. Those prior tees have performed however, the present invention also increases the rate of bulk material unloading. In doing so, the present invention allows a driver to complete an unloading fifteen to twenty three minutes sooner than before. Field tests using 1600 cubic foot trailers in dedicated local runs provided drivers up to twenty minute reductions in unloading times compared to existing tees. Faster unloading leads to more impressed customers, more satisfied drivers, and more loads, or hauls, per day, week or month thus improving revenues to trucking companies.
Further, during unloading of a hopper trailer, the truck remains idling as it provides blower air in some cases. An idling truck often consumes a gallon of diesel fuel per hour. During usage of the invention, unloading raises a truck's engine speed to three times that of ordinary idling, measured in RPM, and consumes three gallons of diesel fuel per hour of unloading. As diesel fuel prices fluctuate in the vicinity of $4 per gallon, reducing idling saves trucking companies a significant expense, at least $500 per year during unloading depending on loads per day. The present invention, lowering unloading times noticeably, reduces idling times of trucks thus, leading to fuel cost savings. The present invention increases the operating efficiencies of trucks when measured in miles per gallon or hours per gallon thanks to decreased unloading times. The present invention aids truckers and their companies in using less diesel fuel to accomplish the same unloading job.
It is, therefore, the principal object of this invention is to provide a fluted hopper tee for inducing directional flow that increases the rate of unloading bulk materials from a container by approximately twenty two per cent, where the increase in unloading rate varies by the type of bulk granular material unloaded.
Still another object of this fluted hopper tee is to increase the clearance from the lowest extent of the horizontal pipe to the ground surface when the invention is installed.
Still another object of this fluted hopper tee is to meet dimensional and clearance requirements of federal and state agencies along with trucking and material handling industry standards.
Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door provides a flush fit to the inside surface of the horizontal pipe.
Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door prevents leakage of fine particulate matter from the hopper tee.
Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the gasket and door of the invention can be readily removed for cleaning, such as washing, and when changing between unloading of different materials.
Still another object of this fluted hopper tee is to improve the accessibility of the door and handle of the bottom drop embodiment of the invention, this accessibility includes door attachment ears arranged symmetrically with a symmetrical door and gasket allowing for installation facing either the left or the right side of a trailer.
Still another object of this fluted hopper tee is to improve the accessibility of the door and other moving parts of the bottom drop embodiment of the invention where the gasket can be removed by hand.
Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door is opened and later secured by an operator using a single handle, or cam lever.
Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door avoids securement by two or more bolts and retainers that formerly permitted misalignment of the door and leakage of bulk materials.
Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door opens readily after an extended period of non-usage, such as six months.
Still another object of this fluted hopper tee is to provide a bottom drop embodiment of the invention where the door opens readily, such as upon polymer bushings, with a minimum of lubrication and its risk of load contamination.
These and other objects may become more apparent to those skilled in the art upon review of the summary of the invention as provided herein, and upon undertaking a study of the description of its preferred embodiment, in view of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In referring to the drawings,
FIG. 1 shows an isometric view of the present invention ready for installation upon a valve and into an unloading line;
FIG. 2 shows a side view of the present invention with the outlet to the left of the figure;
FIG. 3 describes an end view of the present invention through the outlet;
FIG. 4 shows longitudinal section view of the tee;
FIG. 5 shows a top view of the tee with the outlet to the left of the figure;
FIG. 6 shows an alternate embodiment of the invention where the flange has braces to the tee;
FIG. 7 describes an end view of the alternate embodiment;
FIG. 8 illustrates an end view of the drop tee embodiment of the present invention;
FIG. 9 describes a side view of the drop tee embodiment;
FIG. 10 illustrates a side view of the drop tee without the door;
FIG. 11 illustrates a sectional view of the drop tee also without the door;
FIG. 12 is a top view of the drop tee;
FIG. 13 illustrates a sectional view through the door and hinges of the drop tee;
FIG. 14 described an end view of the drop tee with the pivot hinges removed;
FIG. 15 then provides an exploded view of the drop tee;
FIGS. 16A and 16B then show an alternate embodiment of the drop tee having a low profile;
FIG. 17 provides a sectional view of the low profile drop tee;
FIG. 18 shows an end view of the low profile drop tee; and,
FIG. 19 provides an exploded view of the low profile drop tee.
The same reference numerals refer to the same parts throughout the various figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In referring to the drawings, FIG. 1 shows an integral tee, generally known as a hopper tee, of the present invention 1 in a perspective view. The present invention has a generally transverse hollow pipe, hereinafter horizontal pipe 2 , round in cross section and of a known diameter. The horizontal pipe has two opposed ends, one end being an inlet 3 that receives material sent into the hopper tee under pneumatic pressures and the opposite end being an outlet 4 that discharges material from the inlet and material unloaded from a hopper, or bin, into the hopper tee. The inlet and the outlet each have a perimeter slot 5 for coupling the invention 1 into a pneumatic system for unloading. The coupling slots 5 generally extend around the entire circumference of the lower pipe proximate the inlet and the outlet.
Generally centered upon and perpendicular to the horizontal pipe, the fluted hopper tee 1 has a vertically directed hollow pipe, hereinafter vertical pipe 6 . The horizontal pipe is generally transverse, or perpendicular to the vertical pipe. The vertical pipe is also round in cross section and of a known diameter. The vertical pipe has a flange 7 at one end away from the horizontal pipe. The flange extends outwardly from the pipe in a planar form that is parallel to the longitudinal axis of the lower pipe. The flange has a top surface 7 a and pattern of holes therethrough that mates with bolts present in valves commonly used in the bulk material hauling industry. In this embodiment, the flange has a truncated round shape where the flange has two mutually parallel straight edges 8 , also parallel to the longitudinal axis of the lower pipe. Centered upon the flange, the vertical pipe has an opening 9 that matches the inside diameter of the valves upon hopper used in the bulk material industry.
Where the flange adjoins the vertical pipe, generally as the top surface meets the opening 9 , like at a lip, the key feature of the invention begins. The invention provides a flute 10 , or a rounded groove, to the interior of the vertical pipe that begins at the flange and extends in a curvilinear manner into the horizontal pipe in the direction of the outlet. The flute has an initial width comparable to the diameter of the opening 9 then the width of the flute narrows as it approaches the outlet 4 . The path of the flute is generally shown with a flute line 11 that follows a radius of curvature with a center point proximate the outlet 4 . As the flute extends from the flange and curves towards the outlet, the flute tapers in its diameter over an area of transition 14 that may appear as a convex shape, or bulge, in later views of the invention. Where the flute intersects with the flange, the vertical pipe has a radius of curvature immediately. The intersection of the flange with the flute defines a fore edge 12 and where the vertical pipe has a typical connection, or square connection, to the flange an aft edge 13 exists. The fore edge extends for over 120 degrees of arc of the opening 9 , centered upon the horizontal pipe. The aft edge occupies the reminder of the perimeter of the opening.
From the side, FIG. 2 shows the present invention and the location and shaping of the flute. The plane of the flange 7 is generally parallel to the centerline of the horizontal pipe 2 . Where the vertical pipe adjoins the flange proximate the inlet, the vertical pipe has a generally square or right angle joint to the flange. The square joint typically follows the aft edge 13 and has no downstream radius. Opposite the aft edge, the flange has the fore edge 12 which marks the upper extent of the flute 10 . The flute begins at the top surface of the flange and immediately curves as shown in a concave manner towards the outlet 4 through the transition 14 . Opposite the transition, the flute line 11 indicates the position and curvature of the flute as it curves from the flange, through the vertical pipe, and then attains the diameter of the horizontal pipe. The flute line indicates the path of the bulk material as it rounds the juncture of the vertically directed hollow pipe and the transverse hollow pipe. The flute provides an internal transition in the fluid like flow of bulk materials from the vertically directed hollow pipe through a substantially ninety degree turn into the transverse hollow pipe.
As described above, the transition 14 has a bulge like appearance as shown in FIG. 3 . The flute 10 begins at the flange 7 and extends forward in the direction of the outlet 4 of the lower pipe 2 . The flute has an initial width similar to that of the valve opening in a hopper as at the fore edge 12 . The flute then narrows in width as it curves upon a radius until it reaches the diameter of the horizontal pipe. Generally, the hopper valve openings exceed the diameter of the horizontal pipe thus the transition 14 starts wide at the flange and tapers to the horizontal pipe 2 . The curvature of the transition also affects the bulge like appearance. The edge of the transition as in this figure defines the flute line 11 .
FIG. 4 shows a sectional view of the invention, lengthwise with the interior exposed, where the key feature operates to accelerate the flow of bulk granular material through the hopper tee. The flange 7 is generally shown horizontal and parallel to the longitudinal axis of the horizontal pipe. The flange has a fore edge 12 at the opening 9 towards the outlet 4 and an opposite aft edge 13 towards the inlet 3 . The aft edge defines a square edge that connects the flange, the vertical pipe, and the horizontal pipe. Then the fore edge begins the flute where the vertical pipe intersects the top surface of the flange. The flute curves in a concave manner from the fore edge, through the transition, and reaches the horizontal pipe behind the coupling slot 5 near the outlet 4 . Opposite the fore edge, the flute abuts the aft edge and extends as a curvilinear line 11 from the flange through the vertical pipe and partly into the horizontal pipe. As the flute extends across the diameter of the vertical pipe and partly around the circumference, the flute adjoins the inner wall of the vertical pipe, as at 6 a.
As soon as the bulk material, or product, leaves the tank, hopper, or tank valve, the bulk material enters the uniquely designed flute of this invention. The flute line begins at the top surface of the flange more than half way across the diameter of the opening 9 and descends at a slight curve towards the outlet through the vertical pipe and into the horizontal pipe. Inside the horizontal pipe, at less than half of the diameter of the horizontal pipe the flute line curves more sharply and attains an asymptotic angle to the centerline of the horizontal pipe. The flute line ends at a confluence point, 15 , proximate the outlet slightly below the centerline. At the end of the flute line 11 , the flute has reached a width identical to that of the inside diameter of the horizontal pipe. Where the flute begins to curve more sharply, an inflection point, as at 16 , starts an eddy line 17 that extends to the intersection of the vertical pipe with the horizontal pipe at 18 . Above the eddy line 17 within the aft edge 13 and outside the flute line 11 , eddies form in the bulk material flowing from the inlet into the horizontal pipe. The present invention creates less eddy currents and turbulence than prior art tees which leads to less friction between the bulk material and the invention and internal friction of the bulk material. The eddies in the material flow ease the merge of bulk material flowing from the opening 9 into the flute 10 and then follow a curved flow path induced by the flute 10 . The fewer eddy currents and more laminar like flow of the bulk material generates less friction and less heat imparted to the invention which allows for a longer useful life compared to prior art tees. The bulk material flow into the horizontal pipe from the inlet starts the bulk material immediately to drop through the opening 9 into a curved flow through the hopper. The bulk material flowing along a curve merges with that flowing along the horizontal pipe much like two watercourses at a confluence become one river.
Bernoulli's principle reminds us that energy is conserved across a straight pipe and through various joints including a hopper tee. Under the Bernoulli equation, the head of the fluidized bulk material entering the fluted hopper tee equals the head of the fluidized bulk material exiting the outlet 4 where head represents the pressure, kinetic, and potential energies. This relationship is shown in the following equation:
p 1 γ + v 1 2 2 g + z 1 + p 2 γ + v 2 2 2 g + z 2 = p 3 γ + v 3 2 2 g + z 3
Where the bulk material energies at the inlet 1 are added with those of the opening 2 to equal those energies of the outlet 3 . The inlet energies and the opening energies create two forces, one force from the tank pressure pushing the bulk material down the tank, and a second force from the line pressure pulling the bulk material down the line beneath the tank or hopper for distribution. The tank pressure is approximately 25 psi while the line pressure is approximately 20 psi. As the potential energy of the bulk material flowing through the opening adds to the kinetic energy of the material from the inlet, the combined material exits the outlet at a greater velocity and thus accelerates unloading of each hopper and an entire trailer of hoppers. Further, in the vicinity of the inner wall 6 a of the vertical pipe, the flute causes a venturi, or siphon like, effect that aids in drawing, or pulling, bulk material from the hopper, through the valve, into the opening 9 , and thus into the horizontal pipe. Additionally, the bulk material within the flute attains a pressure of approximately 15 psi while the material arriving from the inlet has a pressure of approximately 20 psi. The pressure gradient between the two flows of material augments the siphoning effect of the curved flow and the eddies formed therein.
And then FIG. 5 shows a top view of the present invention looking through the opening 9 in the flange 7 into the hopper tee 1 , particularly the horizontal pipe 2 . The flange, as before, has a truncated round shape with edges 8 parallel to the length of the horizontal pipe. Within the flange, the opening has the aft edge 13 towards the inlet 3 and extending less than half way around the circumference of the opening. The remainder of the opening has the fore edge 12 that begins the flute 10 that descends through the vertical pipe into the horizontal pipe towards the outlet along the flute lines 11 . Inwardly and towards the inlet from the flute lines 11 , the inner wall 6 a extends upwardly from the flute lines to the flange 7 and occupies the remaining circumference of the opening 9 as the aft edge. In this view, the flute lines define a partly parabolic curve with its vertex towards the inlet upon the centerline of the horizontal pipe. The flute lines widen outwardly reaching the inside diameter of the horizontal pipe towards the outlet.
Turning to FIG. 6 , an alternate embodiment of the present invention is shown with a more rigid vertical pipe 6 . This hopper tee has a vertical pipe that merges with a horizontal pipe 2 as previously shown in FIG. 2 . The vertical pipe has a flange 7 generally centered upon and perpendicular to the vertical pipe and parallel to the horizontal pipe. The flange has an opening as at 9 for admitting bulk material from the valve of a hopper. Beneath the flange, a plurality of braces 19 extend from the bottom surface 7 b of the flange at an angle towards the vertical pipe. The braces, or gussets, are generally parallel to one another and perpendicular to the longitudinal axis of the horizontal pipe. The braces have a generally triangular shape of varying depth, as in FIG. 7 , with the shortest depths locating forward in the transition 14 and the greatest depth locating proximate the aft edge 13 and towards the inlet 3 . As before, the vertical pipe has a flute 10 defining the transition 14 from the diameter of the opening 9 through an arc to the diameter of the horizontal pipe. The transition begins immediately at the top surface 7 a of the flange at the opening 9 along a portion of the circumference of the opening, the fore edge 12 . This alternate embodiment applies generally when lighter weight materials are used for the construction of the invention such as aluminum and polymers. The braces serve to stiffen the flange in its connection to a hopper valve and during the vibrations of unloading.
FIG. 8 then shows a drop tee embodiment of the present invention. This embodiment has an opening as at 9 through the flange that receives bulk material from the hopper or bin. The opening has a known shape and width, round with a diameter in this description. Opposite the opening, this embodiment of the hopper tee has a door 101 that opens below a horizontal pipe 102 . As later shown, the door provides a full port opening, or a drop opening 120 , later shown in FIG. 10 , of the same width and shape as opening 9 for unimpeded discharge of bulk material from the hopper or bin. Beneath the flange, the drop tee embodiment has a vertical pipe 106 that merges with the center of the horizontal pipe 102 . In this view, the vertical pipe has a flute 110 that curves from the opening 9 towards the inlet 3 in a transition 114 that contracts in width from that of the opening to that of the diameter of the horizontal pipe. Generally behind the transition towards the outlet, this embodiment has a pair of pivot ears 121 and an opposite pair of hinge ears 122 where each pair is collinear and extending perpendicular to the vertical pipe and to the horizontal pipe. Each member of a pair of pivot ears and hinge ears is coaxial and coplanar with its opposite counterpart. The pivot ears and hinge ears have a symmetric arrangement about the centerline that allows for changing the door position to either side of a trailer during usage. The pivot ears extend outwardly from the centerline of the horizontal pipe and provides a pivoting point for a pin 121 a within a bushing 121 b for a cam bolt 123 , wherein the bushing is generally a polymer. The cam bolt has a threaded end 123 a in a bolted connection through the pin and bushing and opposite the threaded end it has a hook 123 b . Between the threaded end and the hook, the cam bolt has an off center bend defined by the threaded end approaching the hook or a generally convex shape as shown in the figure. The cam bolt 123 allows a cam lever 124 to pivot downwardly from one end of the door 101 as the door itself pivots beneath the horizontal pipe for opening to drop bulk material. The cam lever has a generally elongated shape with two opposed ends. One end is the pedal 124 a that has a foot grip surface to receive a kick from a trucker during opening. A trucker steps on the pedal, or pulls it downward, which allows for easy opening of the door that swings downwardly out and away from the horizontal pipe. With the present invention, the trucker no longer deals with seized wing nuts, rusted bolts, and galled bolts that accumulated in prior art tees in field use. The pedal has a slight offset as shown in FIG. 15 . On the other end, the pedal has a shoulder 124 b generally curved upwardly partially around the door. Near the bottom of the shoulder, it has a groove 124 c that receives the hook 123 b . Near the top of the shoulder, an aperture 124 d admits a pin 124 f , through a bushing 124 g , that pivotally connects the shoulder and the cam lever to the door 101 . The cam lever also includes receives a safety pin, marking strap, or security seal through a second aperture 124 e that secures the cam lever upwardly towards the hinge ear 122 to prevent inadvertent opening of the cam lever.
Then the hinge ear 122 extends outwardly from the vertical pipe along the same axis as the pivot ear 121 and provides a door hinge 125 with a bushing 125 a and a coaxial pin 125 b . The door hinge allows the door to pivot upon one edge opposite the pivot ear 121 and opposite the aperture 124 d but above the second aperture 124 e of the cam lever from a closed to an open position. The cam bolt 123 has threaded rod like connections that allow for adjustments in positioning of the door upon the horizontal pipe. Here in FIG. 8 , the door is shown in the closed position where the door 101 abuts a gasket 101 a that compresses upon the lip 126 defining the drop opening 120 . The gasket seals the door in a positive seal to the door in one motion without adjusting the door at two places as in the prior art. The gasket can be readily replaced if damaged or worn. The door has at least two, preferably four, holes 101 e that admit legs 101 b through the door. The legs are generally elongated cylinders, round in cross section, that have a conically shaped bump out, or barb 101 d , proximate the main portion of the gasket. The barbs 101 d are generally spaced away from the gasket slight less than the door 101 thickness for a snug fit of the gasket to the door. The molded gasket has a generally elliptical shape with an open interior and four legs equally spaced upon the inside face of the gasket. The legs align the gasket upon the door in position for a tight seal. When closed in particular, the door in cooperation with the gasket seals to the horizontal pipe so that the inside surface of the door 101 c is flush with the inside diameter of the horizontal pipe. The smooth closure of the door upon the horizontal pipe provides for minimal interruption in the flow of bulk material and lessens the Reynolds number of the bulk material when passing through the horizontal pipe with the door closed. The lower Reynolds number leads to a more laminar like flow of the bulk material through the invention.
The drop tee embodiment appears from the side in FIG. 9 where a vertical pipe 106 that merges with a horizontal pipe 102 . This embodiment has more ground clearance that prior art tees with generally approximately 1½ inches more between the lowest point of the door and the ground. The horizontal pipe has an inlet 3 and an opposite outlet 4 each with a coupling slot 5 as before. The vertical pipe 106 has a flange 7 with an opening 9 that receives bulk material from the hopper or bin above the drop tee. The flange has a top surface 7 a that intersects along part of the perimeter of the opening with the vertical pipe defining the aft edge 13 . Upon the reminder of the opening 9 , the fore edge 12 defines the beginning of the flute 110 . The flute curves the vertical pipe forward towards the outlet and begins with a width that of the opening 9 in the flange and then narrows to the diameter of the horizontal pipe. In this embodiment, the flute extends to the immediate vicinity of the coupling slot 5 .
Generally centered between the wall 6 a of the vertical pipe 106 and the transition 114 of the flute 110 , the pair of pivot ears 121 provides two parallel plates to which the cam bolt 123 secures upon the bushing 121 b with its internal coaxial pin 121 a. The cam bolt has its threaded end 123 a passing through a hole in the bushing and the pin secured by two nuts equally spaced about the diameter of the bushing. The cam bolt extends outwardly from the horizontal pipe and bends around the shoulder 124 b of the cam lever 124 , generally outside of the door. The cam bolt extends downwardly so that its hook 123 b engages the groove 124 c of the cam lever 124 . The cam lever extends beneath and across the door 101 to the opposite side of the drop tee. The door has an inverted saddle like shape that matches the curvature of the horizontal pipe but also rises to allow for a snug fit of the cam lever beneath the door but tight towards the tee. The door seals to the drop opening 120 upon the gasket 101 a which compresses upon the lip 126 . The lip and the drop opening curve upwardly, as in a saddle, to slightly above the centerline of the horizontal pipe. The perimeter of the door, in this drop embodiment, extends slightly outwardly from the lip causing a reduction in ground clearance below the door of approximately one inch.
FIG. 10 then shows the drop tee with the door 101 , the cam bolt 123 , and the cam lever 124 removed. FIG. 10 is in the opposite direction as FIG. 9 . Beneath the hinge ears 122 , the drop tee has the drop opening 120 generally of similar diameter as the opening 9 in the flange 7 as later shown in FIG. 12 . In this view, the drop opening is bounded by the lip 126 that has a curvi-linear shape upwardly into the lower pipe until the uppermost tangent to the arc is generally parallel to and slightly below the centerline of the horizontal pipe. Alternatively, the lip has a shape of one of parabolic, elliptic, or arcuate. The lip extends slightly outwardly from the surface of the horizontal pipe and provides a slightly concave surface forming a door bead 127 that accepts the gasket 101 a in compression by the door 101 when closed upon the tee. The shape of the lip and the drop opening minimizes the potential disturbance to the inside surface of the horizontal pipe and impediment of bulk material during unloading.
The drop tee in regards to the door and its closure upon the horizontal pipe has a lengthwise sectional view shown in FIG. 11 in the same direction as FIG. 10 . This figure illustrates the immediate curvature of the flute 110 at the top surface 7 a of the flange 7 that extends just short of the coupling slot 5 . Opposite the flute, the vertical pipe has an internal wall 106 a generally square to the top surface of the flange and towards the inlet 3 . The flange has its opening 9 that abuts the valve of a hopper or bin. The opening has a known diameter, often 5 or 6 inches, and the drop tee locates the drop opening 120 directly opposite the opening 9 in the flange. The drop opening has the same inside diameter as the inside diameter of the opening in the flange and follows the circumference of the horizontal pipe. By providing the drop opening with the same diameter as the opening above, the bulk material falls vertically through the drop tee when the door is opened in a smooth flow without any hindrances. The falling bulk material does not constrict to pass through the door nor do eddy currents arise and nor does turbulence develop. This figure further shows the lip 126 extending outwardly from the surface of the horizontal pipe and having a rounded edge towards the drop opening 120 . The horizontal pipe 3 merges with the vertical pip 106 along the upright curvi-linear feature 3 a. Alternatively, the feature has a shape of one of parabolic, elliptic, or arcuate.
FIG. 12 then provides a top view of the drop tee with the door, cam lever, cam bolt, and gasket removed. As can be seen, the opening 9 in the flange is concentric with the drop opening 120 located there below and of similar diameter. Bulk material dropping through the opening 9 and the drop opening 120 flows through the drop tee freely when the door is opened. As before, the drop tee has a flange 7 with a pattern of holes thereon for mounting to the valve of a hopper or bin. The flange has a generally round shape but for two parallel edges 8 each also parallel to the centerline of the horizontal pipe. Beneath the edges, the pair of pivot ears 121 and the pair of hinge ears 122 extend mutually opposite and outwardly from the vertical pipe. This view also shows the horizontal pipe widening slightly at its saddle, as at 102 a , with the vertical pipe. Then the horizontal pipe attains the diameter of the opening 9 across the junction with the vertical pipe. The horizontal pipe continues itself with the diameter of the opening 9 to for a length slightly less than the radius of the flange as at 102 b. Then the horizontal pipe quickly narrows to the diameter proximate the outlet 4 . This widened horizontal pipe before the outlet differs from the preferred embodiment where the transition narrows gradually and further behind the outlet.
Turning the drop tee, FIG. 13 shows a sectional view through the center of the pairs of pivot ears 121 and hinge ears 122 , looking through outlet 4 towards inlet 3 or upstream, where the door closes upon the gasket that compresses upon the lip 126 . The door has a radius of curvature that spans from a lip 126 to the opposite lip across the horizontal pipe. At the location of this section, the lips 126 are spaced apart by the diameter of the opening 9 that exceeds the diameter of the horizontal pipe and the lips are connected by the door bead 127 that in time abuts the gasket. The door radius of curvature and the arcuate length of the door cooperate so that the lowest portion of the door matches the arc at the bottom of the horizontal pipe. The matching of door curvature to the curvature of the horizontal pipe provides a flush and smooth surface to the interior of the drop tee when the door is closed and the tee functions as a hopper tee. Above and behind the door in this figure, the horizontal pipe widens into the flute that begins along the feature line 3 a and that briefly widens into the flute 10 and then narrows to the bottom of the horizontal pipe along the flute line 11 .
Next, FIG. 14 shows the drop tee embodiment in a sectional view towards the outlet 4 and with the pivot ears 121 and hinge ears 122 shown generally having the same horizontal centerline and symmetric positioning. This view is located slightly forward of the section in FIG. 13 towards the outlet. In this location, the door closes upon the horizontal pipe and provides a flush and smooth interior surface. Upon the exterior, the door extends slightly outward from the surface of the horizontal pipe because of the lip.
And, FIG. 15 shows an exploded view of the components of the drop tee. This description begins with the bottom of the figure and moves upwardly through the invention. Here, the invention is in the closed position with the cam lever 124 in a generally horizontal orientation but perpendicular to the line of flow through the invention. The cam lever has a foot pedal 124 a used by truckers and others to open the invention for discharge of product through the opening 9 in the flange 7 and then the bottom opening 120 . Inward from the foot pedal, the cam lever has a second aperture 124 e that receives a seal or other marking device. Opposite the foot pedal, the cam lever has its shoulder 124 b that has a greater width than the remainder of the cam lever and curves upwardly. The shoulder has a groove 124 c generally centered therein that receives the hook 123 b of the cam bolt 123 as previously described. The shoulder curves upwardly above the level of the foot pedal and has an aperture 124 d therethrough with an axis perpendicular to the length of the cam lever. The aperture receives a cam pin 124 f that fits within a coaxial cam bushing 124 g. The cam pin provides a pivotal connection of the cam lever to the door 101 .
The door has a generally saddle shape with an inside surface 101 c having the same radius of curvature as the horizontal pipe 102 . The door curves upwardly and towards the cam shoulder in the figure, the door has two spaced apart door ears 101 h that extend outwardly from the door. Each door ear has an aperture 101 g therethrough that admits the cam bushing 124 g. Opposite the door ears, the door has the door tab 101 j that has an aperture 101 k therethrough that admits a door bushing 101 f. The door bushing cooperates with the hinge ears 122 for opening of the door from the remainder of the tee. The door tab extends from the top of the curve of the door generally outwardly from the door and the horizontal pipe when the door is closed. Within the saddle portion of the door, that is down slope from the door ears 101 h and the door tab 101 j , at least two and preferably four holes 101 e extend through the thickness of the door. The door holes 101 e admit a part of the molded gasket 101 a
The molded gasket 101 a also has a similar saddle shape as the inside face of the door. However, the molded gasket has a large opening therethrough for passage of product. The opening has a diameter of at least that of the opening 9 in the flange. Due to the saddle shape of the gasket, the opening attains a perimeter similar to a section through a spherical body. As described previously, the gasket compresses under closure of the door upon the lip 126 of the horizontal pipe. To prevent the gasket from sliding out of position, the gasket has two, and preferably four, legs 101 b that extend radially outward from the gasket in the direction of the door. The legs align and enter the holes 101 e which positions the gasket properly upon the door. Each leg has a barb 101 d with a generally inverted tapered shape with maximum diameter towards the gasket tapering to the leg diameter away from the gasket. Each barb is also spaced down the leg a distance similar to the depth of the hole 101 e. During installation, a worker pushes the leg into the hole until the barb engages and repeats that for each leg. To remove the gasket, the worker pulls on the leg, lengthening it and narrowing it enough for the barb to pass back through the hole 101 e. Removing the gasket aids the trucker or other worker in cleaning the door and avoids cross contamination of loads. The removable gasket can be removed and cleaned in contrast to prior art drop doors that remained connected to a tee which hindered cleaning and raised the chance of cross contamination with its risk of rejecting a load.
The door with its installed gasket rotates upon its door tab 101 j within the hinge ears 122 of the main portion of the tee. The hinge ears are mutually parallel and spaced apart generally proximate the top of the lower pipe 102 . Each hinge ear has its own aperture that admits a hinge ear bushing 125 a that receives a spring clip pin 125 that passes through the bushing 125 and the door bushing 101 f and allows the door to pivot or to drop away from the tee, as during unloading. Opposite the hinge ears 122 , the tee has the pivot ears 121 where each pivot ear has its own aperture. The apertures of the pivot ears and the hinge ears are spaced symmetrically about the line of flow of the invention to allow for reverse installation of the door if needed in the field. The door of the invention can be installed for right side or left side of trailer usage. Each aperture in a pivot ear receives a pivot bushing 121 b that in turn admits a cam pin 121 generally centered within the pivot ears. The cam pin has a diametrical hole through its centered that admits the threaded end 123 a of a cam bolt 123 . The threaded end has a jam nut 123 c and a washer 123 d inside of the jam nut located outside of the cam pin and a locking nut 123 e inside of the cam pin. The locking nut secures the cam bolt upon the cam pin for hinge action of the cam bolt 123 to the cam lever 124 as previously described.
Inside of the pivot ears and the hinge ears, the invention has the lower pipe 102 with its outlet 4 to the right in this figure. Inside of the outlet, one can view a portion of the door bead 127 denoting the opening 120 in the bottom of the lower pipe. The outlet has its coupling slot 5 inward of the outlet and the lower pipe has the saddle shaped lip 126 below the hinge ears and the pivot ears. The lower pipe continues rearward to an opposite coupling slot 5 and the inlet 3 . The lower pipe merges with the vertical pipe 106 in a generally inverted T position. The lower pipe has a transition section, as at 114 , upon its top surface and towards the outlet that defines the outward appearance of the flute 110 locating upon the downstream portion of the tee. The flute commences at the forward inside edge 12 of the flange 7 . Opposite the forward edge 12 , the flange has an aft edge 13 generally square, or a right angle edge. The flange has two exterior, mutually parallel squared edges 8 , generally parallel to the length of the lower pipe 102 . And the flange 7 extends perpendicular and outwardly from the vertical pipe 106 with a pattern of holes therethrough for mechanical connection.
A further alternate embodiment of the invention is shown in FIGS. 16A , 16 B as a low profile drop tee. Similar to FIG. 9 , this embodiment of the drop tee has a horizontal pipe 202 with a drop opening 220 as later shown in FIG. 17 that is closed by a door. Opposite the door, this embodiment has a flange 7 with a top surface 7 a outwardly from the horizontal pipe and the bottom surface 7 b generally abutting the surface of the horizontal pipe tangentially. This low profile embodiment has more ground clearance that prior art tees with approximately ½ inch more between the lowest point of the door and the ground. The flange has an opening 9 that mates with a valve opening upon a hopper or bin. Upon more than the front half of the opening, the flange has a fore edge 12 that begins a flute that briefly curves in a concave manner from the diameter of the opening 9 to the diameter of the horizontal pipe. This curve begins immediately at the top surface 7 a and then curves through a vertical distance equivalent to the thickness of the flange to attain a horizontal orientation at the horizontal pipe diameter. Opposite the fore edge, the flange has the aft edge 13 that generally provides a square shape. This embodiment effectively has no vertical pipe and thus a higher ground clearance, approximately 1½ inches higher than the previous embodiments. The fore edge and the aft edge generally have a height limited by the thickness of the flange 7 .
Generally behind the transition towards the outlet, this embodiment has a pair of pivot ears 221 and an opposite pair of hinge ears 222 where each pair is collinear and extending perpendicular to the vertical pipe and to the horizontal pipe. Each member of a pair of pivot ears, FIG. 16A , and hinge ears, FIG. 16B , is coaxial and coplanar with its opposite counterpart. The pivot ears and hinge ears have a symmetric arrangement about the centerline that allows for changing the door position to either side of a trailer during usage. Then the hinge ear 222 extends outwardly from the vertical pipe along the same axis as the pivot ear 221 and provides a door hinge 225 with a bushing 225 a and a coaxial pin 225 b . A clevis pin spring retainer 225 c may be optionally used to secure the pin 225 b against dislodging from the bushings during rough movement of the invention beneath a trailer. Beneath the spring retainer, the figure shows a cam lever 224 of a generally elongated shape with two opposed ends. Particularly in FIG. 16A , one end is the pedal 224 a that has an offset foot grip surface to receive a kick from a trucker during opening. Unlike the pedals of FIGS. 8 , 15 , this pedal has a substantial offset as shown, moving the foot pedal to the side and upwardly around the curve of the door which generally contributes to raising the ground clearance of this embodiment of tee.
Here in this figure, the door is in the closed position where the door 201 abuts a gasket 201 a that compresses upon the lip 226 defining the drop opening 220 as described above. The door has preferably four holes 201 e that admit legs 201 b from the gasket through the door. The legs are generally elongated cylinders, round in cross section, that have a conically shaped bump out, or barb 201 d , proximate the main portion of the gasket. The barbs 201 d are generally spaced away from the gasket slight less than the door 201 thickness for a snug fit of the gasket to the door. The molded gasket has a generally elliptical shape with an open interior and four legs equally spaced upon the inside face of the gasket. The legs align the gasket upon the door in position for a tight seal. When closed, the door cooperates with the gasket as it seals to the horizontal pipe so that the inside surface of the door 201 c is flush with the inside diameter of the horizontal pipe. The smooth closure of the door upon the horizontal pipe provides for minimal interruption in the flow of bulk material or change in the Reynolds number through the horizontal pipe with the door closed. The door hinge, shown here as at 222 , allows the door to pivot upon one edge opposite the pivot ears 221 and opposite the aperture 224 d but above the second aperture 224 e of the cam lever from a closed to an open position.
Turning to FIG. 16B , opposite the pedal, the other end of the cam lever has a shoulder 224 b generally curved upwardly partially around the door. Near the bottom of the shoulder, it has a groove 224 c that receives the hook 223 b . Near the top of the shoulder, an aperture 224 d admits a pin 224 f , through a bushing 224 g , that pivotally connects the shoulder and the cam lever to the door 201 . The cam lever also includes receives a safety pin, marking strap, or security seal through a second aperture 224 e proximate the pedal 224 a that secures the cam lever upwardly towards the hinge ear 222 to prevent inadvertent opening of the cam lever.
The drop tee low profile embodiment appears from the side in FIG. 16B where the flange 7 merges with a horizontal pipe 202 . The horizontal pipe has an inlet 3 and an opposite outlet 4 each with a coupling slot 5 as before. The flange 7 has its opening 9 as before that receives bulk material from the hopper or bin above the drop tee. The flange has a top surface 7 a that intersects along part of the perimeter of the opening with the vertical pipe defining the aft edge 13 . Upon the reminder of the opening 9 , the fore edge 12 defines the beginning of the brief flute 210 . The flute curves the forward edge of the flange immediately towards the outlet and begins with a width that of the opening 9 in the flange and then narrows to the diameter of the horizontal pipe. In this embodiment, the flute extends in the direction of flow and towards the immediate vicinity of the coupling slot 5 .
Generally centered slightly beneath the flange 7 and below straight edges 8 , a pair of pivot ears 221 provides two parallel plates to which the cam bolt 223 secures upon the bushing 221 b with its internal coaxial pin 221 a. The cam bolt has its threaded end 223 a passing through a hole in the bushing and the pin secured by two nuts equally spaced about the diameter of the bushing. The cam bolt 223 has threaded rod like connections that allow for adjustments in positioning of the door upon the horizontal pipe. The cam bolt extends outwardly from the horizontal pipe and bends around the shoulder 224 b of the cam lever 224 , generally outside of the door. The cam bolt extends downwardly so that its hook 223 b engages the groove 224 c of the cam lever 224 . The cam lever extends within the depth of the door 201 to the opposite side of the drop tee. The door, as before, has an inverted saddle shape that matches the curvature of the horizontal pipe but also rises to allow for a recessed fit of the cam lever beneath the door but tight towards the tee. The door seals to the drop opening 220 upon the gasket 201 a which compresses upon the lip 226 . The lip and the drop opening curve upwardly, as in a saddle, to slightly above the centerline of the horizontal pipe. The perimeter of the door extends slightly outwardly from the lip causing a reduction in ground clearance below the door of approximately one inch.
Similar to FIG. 11 , FIG. 17 shows a lengthwise sectional view of the low profile embodiment of the present invention. This embodiment has an opening 9 in the flange and a drop opening 220 located opposite each other that have the same diameter when seen from above. Bulk material passes through the opening, the horizontal pipe, and then the drop opening without any constriction and thus has faster unloading than in previous drop tees. The opening has a fore edge 12 generally located towards the outlet 4 . The fore edge has a curve, generally concave, that begins at the top surface 7 a and merges quickly with the inside surface of the horizontal pipe generally opposite the door 201 . Opposite the fore edge, the opening in the flange has the aft edge 13 that extends perpendicular to the top surface and has no curvature towards the inlet. Then opposite the opening 9 , this tee has the drop opening 220 bounded by the lip 226 . The lip extends slightly outward from the surface of the horizontal pipe but provides a flush surface with the interior of the horizontal pipe. The lip extends around the opening as the door bead 227 . The horizontal pipe 102 at the inlet 3 merges with the flange 7 along the upright curvi-linear feature 3 a. Alternatively, the feature has a shape of one of parabolic, elliptic, or arcuate.
And similar to FIG. 8 , FIG. 18 illustrates an end view of the low profile embodiment. This embodiment has an opening as at 9 through the flange that receives bulk material from the hopper or bin. The opening has a known shape and width, round with a diameter in this description. Opposite the opening, this embodiment of the hopper tee has a door 201 that opens below a horizontal pipe 202 and has a drop opening 220 of the same width and shape as opening 9 as in the prior figure for unimpeded discharge of bulk material from the hopper or bin. Beneath the flange, the drop tee embodiment has no vertical pipe but does have the pivot ears 221 and the opposite hinge ears 222 both being collinear and extending perpendicular to the flange and to the horizontal pipe. The pivot ears 221 extend perpendicular beneath the flange and outwardly of the horizontal pipe and provide a pivot point for a cam bolt 223 . The cam bolt turns upon a pin within bushing locating within apertures in the pivot ears. Then the hinge ears 222 , locating opposite the pivot ears in a symmetrically arrangement, allow a cammed handle 224 with a safety pin, or seal wire, removed to pivot downwardly from the horizontal pipe and thus allow the door 201 to open. Then the hinge ears 222 also extend perpendicular and beneath the flange and outwardly from the horizontal pipe and provides a door hinge 225 . The door hinge allows the door to pivot upon one end from a closed to an open position. The cam bolt has threaded rod connections, not shown but within the pivot ears, that allow for adjustments in positioning of the door upon the horizontal pipe. The door is shown here in the closed position where it rests upon the lip 226 defining the drop opening 220 . The door seals upon a gasket 201 , itself upon a raised bead 227 , affixed to the lip. More particularly, the door seals to the horizontal pipe so that the inside surface of the door 201 a is flush with the inside diameter of the horizontal pipe. The smooth closing of the door upon the horizontal pipe provides for less interruption in the flow of bulk material through the horizontal pipe with the door closed.
And, FIG. 19 shows an exploded view of the low profile version of the drop tee components. This description begins at the bottom of the figure and moves upwardly through the invention. Here, the invention is in the closed position with the cam lever 224 in a generally horizontal orientation but perpendicular to the line of flow through the invention. The cam lever has a foot pedal 224 a used by truckers and others to open the invention for discharge of product through the opening 9 in the flange 7 and then the bottom opening 220 . As shown in FIG. 16A , the foot pedal is generally offset in the direction of the outlet 4 thus reducing ground clearance. Inward from the foot pedal, the cam lever has a second aperture 224 e that receives a seal, clip, or other marking device. Opposite the foot pedal, the cam lever has its shoulder 224 b that has a greater width than the remainder of the cam lever and curves upwardly. The shoulder has a centered groove 224 c generally centered therein that receives the hook 223 b of the cam bolt 223 as previously described when the door is in the closed position and releases from the hook when the door is in the opened position (not shown). The shoulder curves upwardly above the level of the foot pedal and has an aperture 224 d therethrough with an axis perpendicular to the length of the cam lever. The aperture receives a cam pin 224 f that fits within a coaxial cam bushing 224 g. The cam pin provides a pivotal connection of the cam lever to the door 201 .
As before, the door has a generally saddle shape with an inside surface 201 c having the same radius of curvature as the horizontal pipe 202 . This horizontal pipe generally joins the flange without a vertical pipe as in the prior embodiment. The door curves upwardly and towards the cam shoulder in the figure and the door has two spaced apart door ears 201 h that extend outwardly from the door. Each door ear has an aperture 201 g therethrough that admits one cam bushing 224 g between the door ears. Opposite the door ears, the door has the door tab 201 j that has an aperture 201 k therethrough that admits one door bushing 201 f into the lone door tab. The door bushing cooperates with the hinge ears 222 for opening of the door from the horizontal pipe 202 and the remainder of this low profile tee. The door tab extends from the top of the curve of the door generally outwardly from the door and the horizontal pipe when the door is closed. Within the saddle portion of the door, that is down slope from the door ears 201 h and the door tab 201 j , at least two and preferably four holes 201 e extend through the thickness of the door. The door holes 201 e admit a part of the molded gasket 201 a and are arranged symmetrically.
The molded gasket 201 a also has a similar saddle shape as the inside face of the door. However, the molded gasket has a large opening therethrough for passage of product. The opening has a diameter of at least that of the opening 9 in the flange. Due to the saddle shape of the gasket, the opening attains a perimeter similar to a section through a spherical body. As described previously, the gasket compresses under closure of the door upon the lip 226 of the horizontal pipe. To keep the gasket in position upon the door and upon the lip when the door is closed, the gasket has two, and preferably four, legs 201 b that extend radially outward from the gasket in the direction of the door. The gasket has a generally symmetrical shape. The legs align and enter the holes 201 e which positions the gasket properly upon the door. Each leg has a barb 201 d , or button head, with a generally inverted tapered shape with maximum diameter towards the gasket tapering to the leg diameter away from the gasket. Each barb is also spaced down the leg a distance similar to the depth of the hole 201 e. During installation, a worker pushes the leg into the hole until the barb engages and repeats that for each leg. To remove the gasket, the worker pulls on the leg, stretching it while narrowing it enough for the barb to pass back through the hole 201 e. Removing the gasket aids the trucker or other worker in cleaning the door and avoids cross contamination of loads. The removable gasket can be removed and cleaned in contrast to prior art drop doors that remained connected to a tee which hindered cleaning and raised the chance of cross contamination with its risk of rejecting a load.
The door with its installed gasket rotates upon its door tab 201 j within the hinge ears 222 of the main portion of the tee. The hinge ears are mutually parallel and spaced apart generally proximate the top of the lower pipe 202 . Each hinge ear has its own aperture that admits a hinge ear bushing 225 a that receives a spring clip pin 225 that passes through the bushing 225 a and the door bushing 201 f and allows the door to pivot away or to drop from the tee, as during unloading. Opposite the hinge ears 222 , the tee has the pivot ears 221 where each pivot ear has its own aperture. The apertures of the pivot ears and the hinge ears are spaced symmetrically about the line of flow of the invention to allow for reverse installation of the door if needed in the field. The door of the low profile tee can be installed for right side or left side of trailer usage. Each aperture in a pivot ear receives a pivot bushing 221 b that in turn admits a cam pin 221 a generally centered within the pivot ears. The cam pin has a diametrical hole through its centered that admits the threaded end 223 a of a cam bolt 223 . The threaded end has a jam nut 223 c and a washer 223 d inside of the jam nut located outside of the cam pin and a locking nut 223 e inside of the cam pin. The locking nut secures the cam bolt upon the cam pin for hinge action of the cam bolt 223 to the cam lever 224 as previously described.
Inside of the pivot ears and the hinge ears, the invention has the lower pipe 202 with its outlet 4 to the right in this figure. Inside of the outlet, one can view a portion of the door bead 227 denoting the opening 220 in the bottom of the lower pipe. The outlet has its coupling slot 5 inward of the outlet and the lower pipe has the saddle shaped lip 226 below the hinge ears and the pivot ears. The lower pipe continues rearward to an opposite coupling slot 5 and the inlet 3 . The lower pipe effectively has no vertical pipe in this embodiment as it merges with the flange 7 . One can see the flute line 11 intersecting with the circumference of the lower pipe slightly below the aft edge 13 . The lower pipe 202 in cooperation with the flange 7 at the forward edge 12 has its brief flute 210 locating upon the downstream portion of the tee. The flute begins immediately at the top surface 7 a of the flange at the forward inside edge 12 . Opposite the forward edge 12 , the flange has an aft edge 13 generally square, or a right angle edge. The flange has two exterior, mutually parallel squared edges 8 , generally parallel to the length of the lower pipe 202 . And the flange 7 extends in a plane generally parallel to the direction of flow and to the length of the lower pipe while it has a pattern of holes therethrough for mechanical connection to a valve body or directly to the hopper, or bin.
In the various embodiments described above, each has a horizontal pipe as called a transverse hollow pipe. In the various embodiments with a vertical pipe, it is also called a vertically directed hollow pipe. And the low profile embodiments exclude a vertical pipe and generally merge the transverse hollow pipe directly to the flange. In the various embodiments, the integral tee has a flute, that is a rounded groove, that provides an internal transition in the flow of bulk material through a substantially ninety degree turn. The flute rounds the flow of bulk material where the vertically directed hollow pipe or the flange merges with the transverse hollow pipe.
The fluted hopper tee and its various components may be manufactured from many materials, including but not limited to, steel, aluminum, polymers, ferrous and non-ferrous metals, their alloys, polymers, high density polyethylene, polypropylene, silicone, nylon, rubber, ceramics, and composites. The door gasket is preferably made from rubber, silicone, nitrile, EPDM, or fluorocarbon, suitable for contact with food ingredients and of sufficient durometer to withstand increased air flow and pressures. The various bushings in the embodiments of this invention are generally polymer for inserting pins and for maintaining cleanliness. The horizontal pipe, vertical pipe, and flange may also have a zinc surface treatment that resists road grime, salts, other environmental conditions, heat, and abrasion more than existing tees. The tees also have a heat treated steel alloy that accelerates the unloading process unlike some existing tees where the prior alloy components contribute to slowing the unloading process. The heat treated steel alloy also resists abrasion more than prior art tees. Field tests report that the present invention lasts through approximately 98 loads of silica sand while prior steel tees wear away in approximately 80 loads of the same bulk material. The longer life of the present invention leads to a reduction in repair parts expenses and an increase in the time between replacements of tees due to wear from abrasive bulk materials. The metallic parts of the invention can be made of aluminum which lowers the weight of the bottom drop embodiment by seven pounds, or 40%, from existing aluminum drop tees.
Variations or modifications to the subject matter of this development may occur to those skilled in the art upon review of the invention and its various embodiments as described herein. Such variations, if within the spirit of this development, are intended to be encompassed within the scope of the invention as explained. The description of the preferred embodiment and as shown in the drawings, are set forth for illustrative purposes only to show the principles of this fluted hopper tee and its various embodiments. | A directional hopper tee has a fluted interior vertical pipe that merges into a horizontal pipe. The vertical pipe has an opening that connects to a hopper to receive bulk material, or product, and a horizontal pipe centered upon the end of the vertical pipe. The horizontal pipe has an inlet that also receives bulk material and pressurized air from ahead of the hopper and an opposite outlet that discharges the bulk material from the hopper tee. The vertical pipe has a flange that abuts the hopper and an opening in the flange that matches the opening of a valve on the hopper itself. At the opening, the vertical pipe begins to turn towards the outlet of the lower pipe with an internal flute. The flute begins immediately at the flange resulting in a vertical pipe with a curved shape towards the outlet and a square shape towards the inlet. The present invention raises the ground clearance of the horizontal pipe by at least an inch resulting in a hopper tee that clears at least 7 inches above the ground. The hopper tee of the invention also unloads at least 15% more product per minute at temperatures closer to product temperature. Alternate embodiments of the present invention provide a reinforced flange, a drop tee, and a low profile drop tee. The present invention aids in the unloading of bulk materials from various haulers. | 1 |
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/084,791, filed May 8, 1998, and is a Continuation in Part of copending U.S. application Ser. No. 08/632,516, filed Apr. 12, 1996, now U.S. Pat. No. 5,769,880, issued Jun. 23, 1998.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of apparatuses and methods for ablating or coagulating the interior surfaces of body organs. Specifically, it relates to an apparatus and method for ablating the interior linings of body organs such as the uterus and gallbladder.
BACKGROUND OF THE INVENTION
[0003] Ablation of the interior lining of a body organ is a procedure which involves heating the organ lining to temperatures which destroy the cells of the lining or coagulate tissue proteins for hemostasis. Such a procedure may be performed as a treatment to one of many conditions, such as chronic bleeding of the endometrial layer of the uterus or abnormalities of the mucosal layer of the gallbladder. Existing methods for effecting ablation include circulation of heated fluid inside the organ (either directly or inside a balloon), laser treatment of the organ lining, and resistive heating using application of RF energy to the tissue to be ablated.
[0004] U.S. Pat. No. 5,084,044 describes an apparatus for endometrial ablation in which a bladder is inserted into the uterus. Heated fluid is then circulated through the balloon to expand the balloon into contact with the endometrium and to ablate the endometrium thermally. U.S. Pat. No. 5,443,470 describes an apparatus for endometrial ablation in which an expandable bladder is provided with electrodes on its outer surface. After the apparatus is positioned inside the uterus, a non-conductive gas or liquid is used to fill the balloon, causing the balloon to push the electrodes into contact with the endometrial surface. RF energy is supplied to the electrodes to ablate the endometrial tissue using resistive heating.
[0005] These ablation devices are satisfactory for carrying out ablation procedures. However, because no data or feedback is available to guide the physician as to how deep the tissue ablation has progressed, controlling the ablation depth and ablation profile with such devices can only be done by assumption.
[0006] For example, the heated fluid method is a very passive and ineffective heating process which relies on the heat conductivity of the tissue. This process does not account for variations in factors such as the amount of contact between the balloon and the underlying tissue, or cooling effects such as those of blood circulating through the organ. RF ablation techniques can achieve more effective ablation since it relies on active heating of the tissue using RF energy, but presently the depth of ablation using RF techniques can only be estimated by the physician since no feedback can be provided as to actual ablation depth.
[0007] Both the heated fluid techniques and the latest RF techniques must be performed using great care to prevent over ablation. Monitoring of tissue surface temperature is normally carried out during these ablation procedures to ensure the temperature does not exceed 100° C. If the temperature exceeds 100° C., the fluid within the tissue begins to boil and to thereby produce steam. Because ablation is carried out within a closed cavity within the body, the steam cannot escape and may instead force itself deeply into the tissue, or it may pass into areas adjacent to the area intended to be ablated, causing embolism or unintended burning.
[0008] Moreover, in prior art RF devices the water drawn from the tissue creates a path of conductivity through which current traveling through the electrodes will flow. This can prevent the current from traveling into the tissue to be ablated. Moreover, the presence of this current path around the electrodes causes current to be continuously drawn from the electrodes. The current heats the liquid drawn from the tissue and thus turns the ablation process into a passive heating method in which the heated liquid around the electrodes causes thermal ablation to continue well beyond the desired ablation depths.
[0009] Another problem with prior art ablation devices is that it is difficult for a physician to find out when ablation has been carried out to a desired depth within the tissue. Thus, it is often the case that too much or too little tissue may be ablated during an ablation procedure.
[0010] It is therefore desirable to provide an ablation device which eliminates the above-described problem of steam and liquid buildup at the ablation site. It is further desirable to provide an ablation method and device which allows the depth of ablation to be controlled and which automatically discontinues ablation once the desired ablation depth has been reached.
SUMMARY OF THE INVENTION
[0011] The present invention is an apparatus and method of ablating and/or coagulating tissue, such as that of the uterus or other organ. An ablation device is provided which has an electrode array carried by an elongate tubular member. The electrode array includes a fluid permeable elastic member preferably formed of a metallized fabric having insulating regions and conductive regions thereon. During use, the electrode array is positioned in contact with tissue to be ablated, ablation energy is delivered through the array to the tissue to cause the tissue to dehydrate, and moisture generated during dehydration is actively or passively drawn into the array and away from the tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a front elevation view of a first embodiment of an ablation device according to the present invention, with the handle shown in cross-section and with the RF applicator head in a closed condition.
[0013] FIG. 2 is a front elevation view of the ablation device of FIG. 1 , with the handle shown in cross-section and with the RF applicator head in an open condition.
[0014] FIG. 3 is a side elevation view of the ablation device of FIG. 2 .
[0015] FIG. 4 is a top plan view of the ablation device of FIG. 2 .
[0016] FIG. 5A is a front elevation view of the applicator head and a portion of the main body of the ablation device of FIG. 2 , with the main body shown in cross-section.
[0017] FIG. 5B is a cross-section view of the main body taken along the plane designated 5 B- 5 B in FIG. 5A .
[0018] FIG. 6 is a schematic representation of a uterus showing the ablation device of FIG. 1 following insertion of the device into the uterus but prior to retraction of the introducer sheath and activation of the spring members.
[0019] FIG. 7 is a schematic representation of a uterus showing the ablation device of FIG. 1 following insertion of the device into the uterus and following the retraction of the introducer sheath and the expansion of the RF applicator head.
[0020] FIG. 8 is a cross-section view of the RF applicator head and the distal portion of the main body of the apparatus of FIG. 1 , showing the RF applicator head in the closed condition.
[0021] FIG. 9 is a cross-section view of the RF applicator head and the distal portion of the main body of the apparatus of FIG. 1 , showing the configuration of RF applicator head after the sheath has been retracted but before the spring members have been released by proximal movement of the shaft.
[0022] FIG. 10 is a cross-section view of the RF applicator head and the distal portion of the main body of the apparatus of FIG. 1 , showing the configuration of RF applicator head after the sheath has been retracted and after the spring members have been released into the fully opened condition.
[0023] FIG. 11 is a cross-section view of a distal portion of an RF ablation device similar to FIG. 1 which utilizes an alternative spring member configuration for the RF applicator head.
[0024] FIG. 12 is a side elevation view of the distal end of an alternate embodiment of an RF ablation device similar to that of FIG. 1 , which utilizes an RF applicator head having a modified shape.
[0025] FIG. 13 is a top plan view of the ablation device of FIG. 12 .
[0026] FIG. 14 is a representation of a bleeding vessel illustrating use of the ablation device of FIG. 12 for general bleeding control.
[0027] FIGS. 15 and 16 are representations of a uterus illustrating use of the ablation device of FIG. 12 for endometrial ablation.
[0028] FIG. 17 is a representation of a prostate gland illustrating use of the ablation device of FIG. 12 for prostate ablation.
[0029] FIG. 18 is a cross-section view of target tissue for ablation, showing ablation electrodes in contact with the tissue surface and illustrating energy fields generated during bi-polar ablation.
[0030] FIGS. 19A-19C are cross-section views of target tissue for ablation, showing electrodes in contact with the tissue surface and illustrating how varying active electrode density may be used to vary the ablation depth.
[0031] FIG. 20 is a side elevation view, similar to the view of FIG. 2 , showing an ablation device according to the present invention in which the electrode carrying means includes inflatable balloons. For purposes of clarity, the electrodes on the electrode carrying means are not shown.
[0032] FIG. 21 is a side elevation view of a second exemplary embodiment of an ablation device according to the present invention, showing the array in the retracted state.
[0033] FIG. 22 is a side elevation view of the ablation device of FIG. 21 , showing the array in the deployed state.
[0034] FIG. 23 is a top plan view of the applicator head of the apparatus of FIG. 21 .
[0035] FIG. 24 is a cross-sectional top view of the encircled region designated 24 in FIG. 23 .
[0036] FIG. 25A is a perspective view of the electrode array of FIG. 23 .
[0037] FIG. 25B is a distal end view of the applicator head of FIG. 30A .
[0038] FIG. 26A is a plan view of a knit that may be used to form the applicator head.
[0039] FIG. 26B is a perspective view of a strand of nylon-wrapped spandex of the type that may be used to form the knit of FIG. 26A .
[0040] FIGS. 27A, 27B , 27 C are top plan views illustrating triangular, parabolic, and rectangular mesh shapes for use as electrode arrays according to the present invention.
[0041] FIG. 28 is a perspective view showing the flexures and hypotube of the deflecting mechanism of the applicator head of FIG. 23 .
[0042] FIG. 29 is a cross-section view of a flexure taken along the plane designated 29 - 29 in FIG. 23 .
[0043] FIG. 30 is a top plan view illustrating the flexure and spring arrangement of an alternative configuration of a deflecting mechanism for an applicator head according to the present invention.
[0044] FIG. 31 is a cross-sectional side view of the bobbin portion of the apparatus of FIG. 21 .
[0045] FIG. 32A is a side elevation view of the handle of the ablation device of FIG. 21 .
[0046] FIG. 32B is a top plan view of the handle of the ablation device of FIG. 21 . For clarity, portions of the proximal and distal grips are not shown.
[0047] FIG. 33 illustrates placement of the applicator head according to the present invention in a uterine cavity.
[0048] FIG. 34 is a side elevation view of the handle of the ablation apparatus of FIG. 21 , showing portions of the apparatus in cross-section.
[0049] FIG. 35 is a front elevation view of the upper portion of the proximal handle grip taken along the plane designated 35 - 35 in FIG. 32B .
[0050] FIGS. 36A, 36B , and 36 C are a series of side elevation views illustrating the heel member as it becomes engaged with the corresponding spring member.
[0051] FIGS. 37A and 37B are cross-sectional top views of the frame member mounted on the proximal grip section, taken along the plane designated 37 - 37 in FIG. 34 and illustrating one of the load limiting features of the second embodiment. FIG. 37A shows the condition of the compression spring before the heel member moves into abutment with frame member, and FIG. 37B shows the condition of the spring after the heel member moves into abutment with the frame member.
DETAILED DESCRIPTION
[0052] The invention described in this application is an aspect of a larger set of inventions described in the following co-pending applications which are commonly owned by the assignee of the present invention, and are hereby incorporated by reference: U.S. Provisional Patent Application No. 60/084,724, filed May 8, 1998, entitled “APPARATUS AND METHOD FOR INTRA-ORGAN MEASUREMENT AND ABLATION” (attorney docket no. ENVS-400); and U.S. Provisional Patent Application No. ______ filed May 8, 1998, entitled “A RADIO-FREQUENCY GENERATOR FOR POWERING AN ABLATION DEVICE” (attorney docket no. ENVS-500).
[0053] The ablation apparatus according to the present invention will be described with respect to two exemplary embodiments.
[0054] First Exemplary Embodiment—Structure
[0055] Referring to FIGS. 1 and 2 , an ablation device according to the present invention is comprised generally of three major components: RF applicator head 2 , main body 4 , and handle 6 . Main body 4 includes a shaft 10 . The RF applicator head 2 includes an electrode carrying means 12 mounted to the distal end of the shaft 10 and an array of electrodes 14 formed on the surface of the electrode carrying means 12 . An RF generator 16 is electrically connected to the electrodes 14 to provide mono-polar or bipolar RF energy to them.
[0056] Shaft 10 is an elongate member having a hollow interior. Shaft 10 is preferably 12 inches long and has a preferred cross-sectional diameter of approximately 4 mm. A collar 13 is formed on the exterior of the shaft 10 at the proximal end. As best shown in FIGS. 6 and 7 , passive spring member 15 are attached to the distal end of the shaft 10 .
[0057] Extending through the shaft 10 is a suction/insufflation tube 17 ( FIGS. 6-9 ) having a plurality of holes 17 a formed in its distal end. An arched active spring member 19 is connected between the distal ends of the passive spring members 15 and the distal end of the suction/insufflation tube 17 .
[0058] Referring to FIG. 2 , electrode leads 18 a and 18 b extend through the shaft 10 from distal end 20 to proximal end 22 of the shaft 10 . At the distal end 20 of the shaft 10 , each of the leads 18 a , 18 b is coupled to a respective one of the electrodes 14 . At the proximal end 22 of the shaft 10 , the leads 18 a , 18 b are electrically connected to RF generator 16 via an electrical connector 21 . During use, the leads 18 a , 18 b carry RF energy from the RF generator 16 to the electrodes. Each of the leads 18 a , 18 b is insulated and carries energy of an opposite polarity than the other lead.
[0059] Electrically insulated sensor leads 23 a , 23 b ( FIGS. 5A and 5B ) also extend through the shaft 10 . Contact sensors 25 a , 25 b are attached to the distal ends of the sensor leads 23 a , 23 b , respectively and are mounted to the electrode carrying means 12 . During use, the sensor leads 23 a , 23 b are coupled by the connector 21 to a monitoring module in the RF generator 16 which measures impedance between the sensors 25 a , 25 b . Alternatively, a reference pad may be positioned in contact with the patient and the impedance between one of the sensors and the reference pad measured.
[0060] Referring to FIG. 5B , electrode leads 18 a , 18 b and sensor leads 23 a , 23 b extend through the shaft 10 between the external walls of the tube 17 and the interior walls of the shaft 10 and they are coupled to electrical connector 21 which is preferably mounted to the collar 13 on the shaft 10 . Connector 21 , which is connectable to the RF generator 16 , includes at least four electrical contact rings 21 a - 21 d ( FIGS. 1 and 2 ) which correspond to each of the leads 18 a , 18 b , 23 a , 23 b . Rings 21 a , 21 b receive, from the RF generator, RF energy of positive and negative polarity, respectively. Rings 21 c , 21 d deliver signals from the right and left sensors, respectively, to a monitoring module within the RF generator 16 .
[0061] Referring to FIG. 5A , the electrode carrying means 12 is attached to the distal end 20 of the shaft 10 . A plurality of holes 24 may be formed in the portion of the distal end 20 of the shaft which lies within the electrode carrying means 12 .
[0062] The electrode carrying means 12 preferably has a shape which approximates the shape of the body organ which is to be ablated. For example, the apparatus shown in FIGS. 1 through 11 has a bicornual shape which is desirable for intrauterine ablation. The electrode carrying means 12 shown in these figures includes horn regions 26 which during use are positioned within the cornual regions of the uterus and which therefore extend towards the fallopian tubes.
[0063] Electrode carrying means 12 is preferably a sack formed of a material which is non-conductive, which is permeable to moisture and/or which has a tendency to absorb moisture, and which may be compressed to a smaller volume and subsequently released to its natural size upon elimination of compression. Examples of preferred materials for the electrode carrying means include open cell sponge, foam, cotton, fabric, or cotton-like material, or any other material having the desired characteristics. Alternatively, the electrode carrying means may be formed of a metallized fabric. For convenience, the term “pad” may be used interchangeably with the term electrode carrying means to refer to an electrode carrying means formed of any of the above materials or having the listed properties.
[0064] Electrodes 14 are preferably attached to the outer surface of the electrode carrying means 12 , such as by deposition or other attachment mechanism. The electrodes are preferably made of lengths of silver, gold, platinum, or any other conductive material. The electrodes may be attached to the electrode carrying means 12 by electron beam deposition, or they may be formed into coiled wires and bonded to the electrode carrying member using a flexible adhesive. Naturally, other means of attaching the electrodes, such as sewing them onto the surface of the carrying member, may alternatively be used. If the electrode carrying means 12 is formed of a metallized fabric, an insulating layer may be etched onto the fabric surface, leaving only the electrode regions exposed.
[0065] The spacing between the electrodes (i.e. the distance between the centers of adjacent electrodes) and the widths of the electrodes are selected so that ablation will reach predetermined depths within the tissue, particularly when maximum power is delivered through the electrodes (where maximum power is the level at which low impedance, low voltage ablation can be achieved).
[0066] The depth of ablation is also effected by the electrode density (i.e., the percentage of the target tissue area which is in contact with active electrode surfaces) and may be regulated by pre-selecting the amount of this active electrode coverage. For example, the depth of ablation is much greater when the active electrode surface covers more than 10% of the target tissue than it is when the active electrode surfaces covers 1% of the target tissue.
[0067] For example, by using 3-6 mm spacing and an electrode width of approximately 0.5-2.5 mm, delivery of approximately 20-40 watts over a 9-16 cm 2 target tissue area will cause ablation to a depth of approximately 5-7 millimeters when the active electrode surface covers more than 10% of the target tissue area. After reaching this ablation depth, the impedance of the tissue will become so great that ablation will self-terminate as described with respect to the operation of the invention.
[0068] By contrast, using the same power, spacing, electrode width, and RF frequency will produce an ablation depth of only 2-3 mm when the active electrode surfaces covers less than 1% of the target tissue area. This can be better understood with reference to FIG. 19A , in which high surface density electrodes are designated 14 a and low surface density electrodes are designated 14 b . For purposes of this comparison between low and high surface density electrodes, each bracketed group of low density electrodes is considered to be a single electrode. Thus, the electrode widths W and spacings S extend as shown in FIG. 19A .
[0069] As is apparent from FIG. 19A , the electrodes 14 a , which have more active area in contact with the underlying tissue T, produce a region of ablation A 1 that extends more deeply into the tissue T than the ablation region A 2 produced by the low density electrodes 14 b , even though the electrode spacings and widths are the same for the high and low density electrodes.
[0070] Some examples of electrode widths, having spacings with more than 10% active electrode surface coverage, and their resultant ablation depth, based on an ablation area of 6 cm 2 and a power of 20-40 watts, are given on the following table:
ELECTRODE WIDTH SPACING APPROX. DEPTH 1 mm 1-2 mm 1-3 mm 1-2.5 mm 3-6 mm 5-7 mm 1-4.5 mm 8-10 mm 8-10 mm
[0071] Examples of electrode widths, having spacings with less than 1% active electrode surface coverage, and their resultant ablation depth, based on an ablation area of 6 cm 2 and a power of 20-40 watts, are given on the following table:
ELECTRODE WIDTH SPACING APPROX. DEPTH 1 mm 1-2 mm 0.5-1 mm 1-2.5 mm 3-6 mm 2-3 mm 1-4.5 mm 8-10 mm 2-3 mm
[0072] Thus it can be seen that the depth of ablation is significantly less when the active electrode surface coverage is decreased.
[0073] In the preferred embodiment, the preferred electrode spacing is approximately 8-10 mm in the horn regions 26 with the active electrode surfaces covering approximately 1% of the target region. Approximately 1-2 mm electrode spacing (with 10% active electrode coverage) is preferred in the cervical region (designated 28 ) and approximately 3-6 mm (with greater than 10% active electrode surface coverage) is preferred in the main body region.
[0074] The RF generator 16 may be configured to include a controller which gives the user a choice of which electrodes should be energized during a particular application in order to give the user control of ablation depth. For example, during an application for which deep ablation is desired, the user may elect to have the generator energize every other electrode, to thereby optimize the effective spacing of the electrodes and to decrease the percentage of active electrode surface coverage, as will be described below with respect to FIG. 18 .
[0075] Although the electrodes shown in the drawings are arranged in a particular pattern, it should be appreciated that the electrodes may be arranged in any pattern to provide ablation to desired depths.
[0076] Referring to FIGS. 6 and 7 , an introducer sheath 32 facilitates insertion of the apparatus into, and removal of the apparatus from, the body organ to be ablated. The sheath 32 is a tubular member which is telescopically slidable over the shaft 10 . The sheath 32 is slidable between a distal condition, shown in FIG. 6 , in which the electrode carrying means 12 is compressed inside the sheath, and a proximal condition in which the sheath 32 is moved proximally to release the electrode carrying means from inside it ( FIG. 7 ). By compressing the electrode carrying means 12 to a small volume, the electrode carrying means and electrodes can be easily inserted into the body cavity (such as into the uterus via the vaginal opening).
[0077] A handle 34 attached to the sheath 32 provides finger holds to allow for manipulation of the sheath 32 . Handle 34 is slidably mounted on a handle rail 35 which includes a sleeve 33 , a finger cutout 37 , and a pair of spaced rails 35 a , 35 b extending between the sleeve 33 and the finger cutout 37 . The shaft 10 and sheath 32 slidably extend through the sleeve 33 and between the rails 35 a , 35 b . The tube 17 also extends through the sleeve 33 and between the rails 35 a , 35 b , and its proximal end is fixed to the handle rail 35 near the finger cutout 37 .
[0078] A compression spring 39 is disposed around the proximal most portion of the suction/insufflation tube 17 which lies between the rails 35 a , 35 b . One end of the compression spring 39 rests against the collar 13 on the shaft 10 , while the opposite end of the compression spring rests against the handle rail 35 . During use, the sheath 32 is retracted from the electrode carrying means 12 by squeezing the handle 34 towards the finger cutout 37 to slide the sheath 32 in the distal direction. When the handle 34 advances against the collar 13 , the shaft 10 (which is attached to the collar 13 ) is forced to slide in the proximal direction, causing compression of the spring 39 against the handle rail 35 . The movement of the shaft 10 relative to the suction/insufflation tube 17 causes the shaft 10 to pull proximally on the passive spring member 15 . Proximal movement of the passive spring member 15 in turn pulls against the active spring member 19 , causing it to move to the opened condition shown in FIG. 7 . Unless the shaft is held in this retracted condition, the compression spring 39 will push the collar and thus the shaft distally, forcing the RF applicator head to close. A locking mechanism (not shown) may be provided to hold the shaft in the fully withdrawn condition to prevent inadvertent closure of the spring members during the ablation procedure.
[0079] The amount by which the springs 15 , 19 are spread may be controlled by manipulating the handle 34 to slide the shaft 10 (via collar 13 ), proximally or distally. Such sliding movement of the shaft 10 causes forceps-like movement of the spring members 15 , 19 .
[0080] A flow pathway 36 is formed in the handle rail 35 and is fluidly coupled to a suction/insufflation port 38 . The proximal end of the suction/insufflation tube 17 is fluidly coupled to the flow pathway so that gas fluid may be introduced into, or withdrawn from the suction/insufflation tube 17 via the suction/insufflation port 38 . For example, suction may be applied to the fluid port 38 using a suction/insufflation unit 40 . This causes water vapor within the uterine cavity to pass through the permeable electrode carrying means 12 , into the suction/insufflation tube 17 via holes 17 a , through the tube 17 , and through the suction/insufflation unit 40 via the port 38 . If insufflation of the uterine cavity is desired, insufflation gas, such as carbon dioxide, may be introduced into the suction/insufflation tube 17 via the port 38 . The insufflation gas travels through the tube 17 , through the holes 17 a , and into the uterine cavity through the permeable electrode carrying member 12 .
[0081] If desirable, additional components may be provided for endoscopic visualization purposes. For example, lumen 42 , 44 , and 46 may be formed in the walls of the introducer sheath 32 as shown in FIG. 5B . An imaging conduit, such as a fiberoptic cable 48 , extends through lumen 42 and is coupled via a camera cable 43 to a camera 45 . Images taken from the camera may be displayed on a monitor 56 . An illumination fiber 50 extends through lumen 44 and is coupled to an illumination source 54 . The third lumen 46 is an instrument channel through which surgical instruments may be introduced into the uterine cavity, if necessary.
[0082] Because during use it is most desirable for the electrodes 14 on the surface of the electrode carrying means 12 to be held in contact with the interior surface of the organ to be ablated, the electrode carrying means 12 may be provide to have additional components inside it that add structural integrity to the electrode carrying means when it is deployed within the body.
[0083] For example, referring to FIG. 11 , alternative spring members 15 a , 19 a may be attached to the shaft 10 and biased such that, when in a resting state, the spring members are positioned in the fully resting condition shown in FIG. 11 . Such spring members would spring to the resting condition upon withdrawal of the sheath 32 from the RF applicator head 2 .
[0084] Alternatively, a pair of inflatable balloons 52 may be arranged inside the electrode carrying means 12 as shown in FIG. 20 and connected to a tube (not shown) extending through the shaft 10 and into the balloons 52 . After insertion of the apparatus into the organ and following retraction of the sheath 32 , the balloons 52 would be inflated by introduction of an inflation medium such as air into the balloons via a port similar to port 38 using an apparatus similar to the suction/insufflation apparatus 40 .
[0085] Structural integrity may also be added to the electrode carrying means through the application of suction to the proximal end 22 of the suction/insufflation tube 17 . Application of suction using the suction/insufflation device 40 would draw the organ tissue towards the electrode carrying means 12 and thus into better contact with the electrodes 14 .
[0086] FIGS. 12 and 13 show an alternative embodiment of an ablation device according to the present invention. In the alternative embodiment, an electrode carrying means 12 a is provided which has a shape which is generally tubular and thus is not specific to any particular organ shape. An ablation device having a general shape such as this may be used anywhere within the body where ablation or coagulation is needed. For example, the alternative embodiment is useful for bleeding control during laparoscopic surgery ( FIG. 14 ), tissue ablation in the prostate gland ( FIG. 17 ), and also intrauterine ablation ( FIGS. 15 and 16 ).
[0087] First Exemplary Embodiment—Operation
[0088] Operation of the first exemplary embodiment of an ablation device according to the present invention will next be described.
[0089] Referring to FIG. 1 , the device is initially configured for use by positioning the introducer sheath 32 distally along the shaft 10 , such that it compresses the electrode carrying means 12 within its walls.
[0090] At this time, the electrical connector 21 is connected to the RF generator 16 , and the fiberoptic cable 48 and the illumination cable 50 are connected to the illumination source, monitor, and camera, 54 , 56 , 45 . The suction/insufflation unit 40 is attached to suction/insufflation port 38 on the handle rail 35 . The suction/insufflation unit 40 is preferably set to deliver carbon dioxide at an insufflation pressure of 20-200 mmHg.
[0091] Next, the distal end of the apparatus is inserted through the vaginal opening V and into the uterus U as shown in FIG. 6 , until the distal end of the introducer sheath 32 contacts the fundus F of the uterus. At this point, carbon dioxide gas is introduced into the tube 17 via the port 38 , and it enters the uterine cavity, thereby expanding the uterine cavity from a flat triangular shape to a 1-2 cm high triangular cavity. The physician may observe (using the camera 45 and monitor 56 ) the internal cavities using images detected by a fiberoptic cable 48 inserted through lumen 42 . If, upon observation, the physician determines that a tissue biopsy or other procedure is needed, the required instruments may be inserted into the uterine cavity via the instrument channel 46 .
[0092] Following insertion, the handle 34 is withdrawn until it abuts the collar 13 . At this point, the sheath 32 exposes the electrode carrying member 12 but the electrode carrying member 12 is not yet fully expanded (see FIG. 9 ), because the spring members 15 , 19 have not yet been moved to their open condition. The handle 34 is withdrawn further, causing the shaft 10 to move proximally relative to the suction/insufflation tube 17 , causing the passive spring members 15 to pull the active spring members 19 , causing them to open into the opened condition showing in FIG. 10 .
[0093] The physician may confirm proper positioning of the electrode carrying member 12 using the monitor 56 , which displays images from the fiberoptic cable 48 .
[0094] Proper positioning of the device and sufficient contact between the electrode carrying member 12 and the endometrium may further be confirmed using the contact sensors 25 a , 25 b . The monitoring module of the RF generator measures the impedance between these sensors using conventional means. If there is good contact between the sensors and the endometrium, the measured impedance will be approximately 20-180 ohm, depending on the water content of the endometrial lining.
[0095] The sensors are positioned on the distal portions of the bicornual shaped electrode carrying member 12 , which during use are positioned in the regions within the uterus in which it is most difficult to achieve good contact with the endometrium. Thus, an indication from the sensors 25 a , 25 b that there is sound contact between the sensors and the endometrial surface indicates that good electrode contact has been made with the endometrium.
[0096] Next, insufflation is terminated. Approximately 1-5 cc of saline may be introduced via suction/insufflation tube 17 to initially wet the electrodes and to improve electrode electrical contact with the tissue. After introduction of saline, the suction/insufflation device 40 is switched to a suctioning mode. As described above, the application of suction to the RF applicator head 2 via the suction/insufflation tube 17 collapses the uterine cavity onto the RF applicator head 2 and thus assures better contact between the electrodes and the endometrial tissue.
[0097] If the generally tubular apparatus of FIGS. 12 and 13 is used, the device is angled into contact with one side of the uterus during the ablation procedure. Once ablation is completed, the device (or a new device) is repositioned in contact with the opposite side and the procedure is repeated. See. FIGS. 15 and 16 .
[0098] Next, RF energy at preferably about 500 kHz and at a constant power of approximately 30 W is applied to the electrodes. As shown in FIG. 5 a , it is preferable that each electrode be energized at a polarity opposite from that of its neighboring electrodes. By doing so, energy field patterns, designated F 1 , F 2 and F 4 in FIG. 18 , are generated between the electrode sites and thus help to direct the flow of current through the tissue T to form a region of ablation A. As can be seen in FIG. 18 , if electrode spacing is increased such by energizing, for example every third or fifth electrode rather than all electrodes, the energy patterns will extend more deeply into the tissue. (See, for example, pattern F 2 which results from energization of electrodes having a non-energized electrode between them, or pattern F 4 which results from energization of electrodes having two non-energized electrodes between them).
[0099] Moreover, ablation depth may be controlled as described above by providing low surface density electrodes on areas of the electrode carrying member which will contact tissue areas at which a smaller ablation depth is required (see FIG. 19A ). Referring to FIG. 19B , if multiple, closely spaced, electrodes 14 are provided on the electrode carrying member, a user may set the RF generator to energize electrodes which will produce a desired electrode spacing and active electrode area. For example, alternate electrodes may be energized as shown in FIG. 19B , with the first three energized electrodes having positive polarity, the second three having negative polarity, etc.
[0100] As another example, shown in FIG. 19C , if greater ablation depth is desired the first five electrodes may be positively energized, and the seventh through eleventh electrodes negatively energized, with the sixth electrode remaining inactivated to provide adequate electrode spacing.
[0101] As the endometrial tissue heats, moisture begins to be released from the tissue. The moisture permeates the electrode carrying member 12 and is thereby drawn away from the electrodes. The moisture may pass through the holes 17 a in the suction/insufflation tube 17 and leave the suction/insufflation tube 17 at its proximal end via port 38 as shown in FIG. 7 . Moisture removal from the ablation site may be further facilitated by the application of suction to the shaft 10 using the suction/insufflation unit 40 .
[0102] Removal of the moisture from the ablation site prevents formation of a liquid layer around the electrodes. As described above, liquid build-up at the ablation site is detrimental in that provides a conductive layer that carries current from the electrodes even when ablation has reached the desired depth. This continued current flow heats the liquid and surrounding tissue, and thus causes ablation to continue by unpredictable thermal conduction means.
[0103] Tissue which has been ablated becomes dehydrated and thus decreases in conductivity. By shunting moisture away from the ablation site and thus preventing liquid build-up, there is no liquid conductor at the ablation area during use of the ablation device of the present invention. Thus, when ablation has reached the desired depth, the impedance at the tissue surface becomes sufficiently high to stop or nearly stop the flow of current into the tissue. RF ablation thereby stops and thermal ablation does not occur in significant amounts. If the RF generator is equipped with an impedance monitor, a physician utilizing the ablation device can monitor the impedance at the electrodes and will know that ablation has self-terminated once the impedance rises to a certain level and then remains fairly constant. By contrast, if a prior art bipolar RF ablation device was used together with an impedance monitor, the presence of liquid around the electrodes would cause the impedance monitor to give a low impedance reading regardless of the depth of ablation which had already been carried out, since current would continue to travel through the low-impedance liquid layer.
[0104] Other means for monitoring and terminating ablation may also be provided. For example, a thermocouple or other temperature sensor may be inserted to a predetermined depth in the tissue to monitor the temperature of the tissue and terminate the delivery of RF energy or otherwise signal the user when the tissue has reached a desired ablation temperature.
[0105] Once the process has self terminated, 1-5 cc of saline can be introduced via suction/insufflation tube 17 and allowed to sit for a short time to aid separation of the electrode from the tissue surface. The suction insufflation device 40 is then switched to provide insufflation of carbon dioxide at a pressure of 20-200 mmHg. The insufflation pressure helps to lift the ablated tissue away from the RF applicator head 2 and to thus ease the closing of the RF applicator head. The RF applicator head 2 is moved to the closed position by sliding the handle 34 in a distal direction to fold the spring members 15 , 19 along the axis of the device and to cause the introducer sheath 32 to slide over the folded RF applicator head. The physician may visually confirm the sufficiency of the ablation using the monitor 56 . Finally, the apparatus is removed from the uterine cavity.
[0106] Second Exemplary Embodiment—Structure
[0107] A second embodiment of an ablation device 100 in accordance with the present invention is shown in FIGS. 21-37B . The second embodiment differs from the first embodiment primarily in its electrode pattern and in the mechanism used to deploy the electrode applicator head or array. Naturally, aspects of the first and second exemplary embodiments and their methods of operation may be combined without departing from the scope of the present invention.
[0108] Referring to FIGS. 21 and 22 , the second embodiment includes an RF applicator head 102 , a sheath 104 , and a handle 106 . As with the first embodiment, the applicator head 102 is slidably disposed within the sheath 104 ( FIG. 21 ) during insertion of the device into the uterine cavity, and the handle 106 is subsequently manipulated to cause the applicator head 102 to extend from the distal end of the sheath 104 ( FIG. 22 ) and to expand into contact with body tissue ( FIG. 33 ).
[0109] RF Applicator Head
[0110] Referring to FIG. 23 , in which the sheath 104 is not shown for clarity, applicator head 102 extends from the distal end of a length of tubing 108 which is slidably disposed within the sheath 104 . Applicator head 102 includes an external electrode array 102 a and an internal deflecting mechanism 102 b used to expand and tension the array for positioning into contact with the tissue.
[0111] Referring to FIGS. 25A and 25B , the array 102 a of applicator head 102 is formed of a stretchable metallized fabric mesh which is preferably knitted from a nylon and spandex knit plated with gold or other conductive material. In one array design, the knit (shown in FIGS. 26A and 26B ) is formed of three monofilaments of nylon 109 a knitted together with single yarns of spandex 109 b . Each yarn of spandex 109 b has a double helix 109 c of five nylon monofilaments coiled around it.
[0112] This knit of elastic (spandex) and inelastic (nylon) yarns is beneficial for a number of reasons. For example, knitting elastic and relatively inelastic yarns allows the overall deformability of the array to be pre-selected.
[0113] The mesh is preferably constructed so as to have greater elasticity in the transverse direction (T) than in the longitudinal direction (L). In a preferred mesh design, the transverse elasticity is on the order of approximately 300% whereas the longitudinal elasticity is on the order of approximately 100%. The large transverse elasticity of the array allows it to be used in a wide range of uterine sizes.
[0114] Another advantage provided by the combination of elastic and relatively inelastic yarns is that the elastic yarns provide the needed elasticity to the array while the relatively inelastic yarns provide relatively non-stretchable members to which the metallization can adhere without cracking during expansion of the array. In the knit configuration described above, the metallization adheres to the nylon coiled around the spandex. During expansion of the array, the spandex elongates and the nylon double helix at least partially elongates from its coiled configuration.
[0115] One process which may be used to apply the gold to the nylon/spandex knit involves plating the knit with silver using known processes which involve application of other materials as base layers prior to application of the silver to ensure that the silver will adhere. Next, the insulating regions 110 (described below) are etched onto the silver, and afterwards the gold is plated onto the silver. Gold is desirable for the array because of it has a relatively smooth surface, is a very inert material, and has sufficient ductility that it will not crack as the nylon coil elongates during use.
[0116] The mesh may be configured in a variety of shapes, including but not limited to the triangular shape S 1 , parabolic S 2 , and rectangular S 3 shapes shown in FIGS. 27A, 27B and 27 C, respectively.
[0117] Turning again to FIGS. 25A and 25B , when in its expanded state, the array 102 a includes a pair of broad faces 112 spaced apart from one another. Narrower side faces 114 extend between the broad faces 112 along the sides of the applicator head 102 , and a distal face 116 extends between the broad faces 112 at the distal end of the applicator head 102 .
[0118] Insulating regions 110 are formed on the applicator head to divide the mesh into electrode regions. The insulated regions 110 are preferably formed using etching techniques to remove the conductive metal from the mesh, although alternate methods may also be used, such as by knitting conductive and non-conductive materials together to form the array.
[0119] The array may be divided by the insulated regions 110 into a variety of electrode configurations. In a preferred configuration the insulating regions 110 divide the applicator head into four electrodes 118 a - 118 d by creating two electrodes on each of the broad faces 112 . To create this four-electrode pattern, insulating regions 110 are placed longitudinally along each of the broad faces 112 as well as along the length of each of the faces 114 , 16 . The electrodes 118 a - 118 d are used for ablation and, if desired, to measure tissue impedance during use.
[0120] Deflecting mechanism 102 b and its deployment structure is enclosed within electrode array 102 a . Referring to FIG. 23 , external hypotube 120 extends from tubing 108 and an internal hypotube 122 is slidably and co-axially disposed within hypotube 120 . Flexures 124 extend from the tubing 108 on opposite sides of external hypotube 120 . A plurality of longitudinally spaced apertures 126 ( FIG. 28 ) are formed in each flexure 124 . During use, apertures 126 allow moisture to pass through the flexures and to be drawn into exposed distal end of hypotube 120 using a vacuum source fluidly coupled to hypotube 120 .
[0121] Each flexure 124 preferably includes conductive regions that are electrically coupled to the array 102 a for delivery of RF energy to the body tissue. Referring to FIG. 29 , strips 128 of copper tape or other conductive material extend along opposite surfaces of each flexure 124 . Each strip 128 is electrically insulated from the other strip 128 by a non-conductive coating on the flexure. Conductor leads (not shown) are electrically coupled to the strips 128 and extend through tubing 108 ( FIG. 23 ) to an electrical cord 130 ( FIG. 21 ) which is attachable to the RF generator.
[0122] During use, one strip 128 on each conductor is electrically coupled via the conductor leads to one terminal on the RF generator while the other strip is electrically coupled to the opposite terminal, thus causing the array on the applicator head to have regions of alternating positive and negative polarity.
[0123] The flexures may alternatively be formed using a conductive material or a conductively coated material having insulating regions formed thereon to divide the flexure surfaces into multiple conductive regions. Moreover, alternative methods such as electrode leads independent of the flexures 124 may instead be used for electrically connecting the electrode array to the source of RF energy.
[0124] It is important to ensure proper alignment between the conductive regions of the flexures 124 (e.g. copper strips 128 ) and the electrodes 118 a - 118 d in order to maintain electrical contact between the two. Strands of thread 134 (which may be nylon) ( FIG. 23 ) are preferably sewn through the array 102 a and around the flexures 124 in order to prevent the conductive regions 128 from slipping out of alignment with the electrodes 118 a - 118 d . Alternate methods for maintaining contact between the array 102 a and the conductive regions 128 include using tiny bendable barbs extending between the flexures 124 and the array 102 a to hook the array to the conductive regions 128 , or bonding the array to the flexures using an adhesive applied along the insulating regions of the flexures.
[0125] Referring again to FIG. 23 , internal flexures 136 extend laterally and longitudinally from the exterior surface of hypotube 122 . Each internal flexure 136 is connected at its distal end to one of the flexures 124 and a transverse ribbon 138 extends between the distal portions of the internal flexures 136 . Transverse ribbon 138 is preferably pre-shaped such that when in the relaxed condition the ribbon assumes the corrugated configuration shown in FIG. 23 and such that when in a compressed condition it is folded along the plurality of creases 140 that extend along its length. Flexures 124 , 136 and ribbon 138 are preferably an insulated spring material such as heat treated 17-7 PH stainless steel.
[0126] The deflecting mechanism is preferably configured such that the distal tips of the flexures 124 are sufficiently flexible to prevent tissue puncture during deployment and/or use. Such an atraumatic tip design may be carried out in a number of ways, such as by manufacturing the distal sections 124 a ( FIG. 28 ) of the flexures from a material that is more flexible than the proximal sections 124 b . For example, flexures 124 may be provided to have proximal sections formed of a material having a modulus of approximately 28×10 6 psi and distal sections having a durometer of approximately 72D.
[0127] Alternatively, referring to FIG. 30 , the flexures 124 may be joined to the internal flexures 136 at a location more proximal than the distal tips of the flexures 124 , allowing them to move more freely and to adapt to the contour of the surface against which they are positioned (see dashed lines in FIG. 30 ). Given that uterine sizes and shapes vary widely between women, the atraumatic tip design is further beneficial in that it allows the device to more accurately conform to the shape of the uterus in which it is deployed while minimizing the chance of injury.
[0128] The deflecting mechanism formed by the flexures 124 , 136 , and ribbon 138 forms the array into the substantially triangular shape shown in FIG. 23 , which is particularly adaptable to most uterine shapes. As set forth in detail below, during use distal and proximal grips 142 , 144 forming handle 106 are squeezed towards one another to withdraw the sheath and deploy the applicator head.
[0129] This action results in relative rearward motion of the hypotube 120 and relative forward motion of the hypotube 122 . The relative motion between the hypotubes causes deflection in flexures 124 , 136 which deploys and tensions the electrode array 102 a.
[0130] Measurement Device
[0131] The ablation device according to the second embodiment includes a measurement device for easily measuring the uterine width and for displaying the measured width on a gauge 146 ( FIG. 21 ). The measurement device utilizes non-conductive (e.g. nylon) suturing threads 148 that extend from the hypotube 122 and that have distal ends attached to the distal portion of the deflecting mechanism ( FIG. 23 ). As shown in FIG. 24 , threads 148 are preferably formed of a single strand 150 threaded through a wire loop 152 and folded over on itself. Wire loop 152 forms the distal end of an elongate wire 154 which may be formed of stainless steel or other wire.
[0132] Referring to FIG. 31 , wire 154 extends through the hypotube 122 and is secured to a rotatable bobbin 156 . The rotatable bobbin 156 includes a dial face 158 preferably covered in a clear plastic. As can be seen in FIG. 32 , dial face 158 includes calibration markings corresponding to an appropriate range of uterine widths. The bobbin is disposed within a gauge housing 160 and a corresponding marker line 162 is printed on the gauge housing. A torsion spring 164 provides rotational resistance to the bobbin 156 .
[0133] Expansion of the applicator head 102 during use pulls threads 148 ( FIG. 23 ) and thus wire 154 ( FIG. 24 ) in a distal direction. Wire 154 pulls against the bobbin 156 ( FIG. 31 ), causing it to rotate. Rotation of the bobbin positions one of the calibration markings on dial face 158 into alignment with the marker line 162 ( FIG. 32B ) to indicate the distance between the distal tips of flexures 124 and thus the uterine width.
[0134] The uterine width and length (as determined using a conventional sound or other means) are preferably input into an RF generator system and used by the system to calculate an appropriate ablation power as will be described below. Alternately, the width as measured by the apparatus of the invention and length as measured by other means may be used by the user to calculate the power to be supplied to the array to achieve the desired ablation depth.
[0135] The uterine width may alternatively be measured using other means, including by using a strain gauge in combination with an A/D converter to transduce the separation distance of the flexures 124 and to electronically transmit the uterine width to the RF generator.
[0136] Control of Ablation Depth
[0137] The most optimal electrocoagulation occurs when relatively deep ablation is carried out in the regions of the uterus at which the endometrium is thickest, and when relatively shallower ablation is carried out in areas in which the endometrium is shallower. A desirable range of ablation depths includes approximately 2-3 mm for the cervical os and the cornual regions, and approximately 7-8 mm in the main body of the uterus where the endometrium is substantially thicker.
[0138] As discussed with respect to the first embodiment, a number of factors influence the ablation depth that can be achieved using a given power applied to a bipolar electrode array. These include the power supplied by the RF generator, the distance between the centers of adjacent electrodes (“center-to-center distance”), the electrode density (i.e., the porosity of the array fabric or the percent of the array surface that is metallic), the edge gap (i.e. the distance between the edges of adjacent electrode poles), and the electrode surface area. Other factors include blood flow (which in slower-ablating systems can dissipate the RF) and the impedance limit.
[0139] Certain of these factors may be utilized in the present invention to control ablation depth and to provide deeper ablation at areas requiring deeper ablation and to provide shallower regions in areas where deep ablation is not needed. For example, as center-to-center distance increases, the depth of ablation increases until a point where the center to center distance is so great that the strength of the RF field is too diffuse to excite the tissue. It can been seen with reference to FIG. 33 that the center to center distance d1 between the electrodes 118 a , 118 b is larger within the region of the array that lies in the main body of the uterus and thus contributes to deeper ablation. The center to center distance d2 between electrodes 118 a , 118 b is smaller towards the cervical canal where it contributes to shallower ablation. At the distal end of the device, the shorter center to center distances d3 extend between top and bottom electrodes 118 b , 118 c and 118 a , 118 d and again contribute to shallower ablation.
[0140] Naturally, because the array 102 a expands to accommodate the size of the uterus in which it is deployed, the dimensions of the array 102 a vary. One embodiment of the array 102 a includes a range of widths of at least approximately 2.5-4.5 cm, a range of lengths of at least approximately 4-6 cm, and a density of approximately 35%-45%.
[0141] The power supplied to the array by the RF generator is calculated by the RF generator system to accommodate the electrode area required for a particular patient. As discussed above, the uterine width is measured by the applicator head 102 and displayed on gauge 146 . The uterine length is measured using a sound, which is an instrument conventionally used for that purpose. It should be noted that calibration markings of the type used on a conventional sound device, or other structure for length measurement, may be included on the present invention to allow it to be used for length measurement as well.
[0142] The user enters the measured dimensions into the RF generator system using an input device, and the RF generator system calculates or obtains the appropriate set power from a stored look-up table using the uterine width and length as entered by the user. An EPROM within the RF generator system converts the length and width to a set power level according to the following relationship:
P=L×W× 5.5
Where P is the power level in watts, L is the length in centimeters, W is the width in centimeters, and 5.5 is a constant having units of watts per square centimeter.
[0143] Alternatively, the user may manually calculate the power setting from the length and width, or s/he may be provided with a table of suggested power settings for various electrode areas (as determined by the measured length and width) and will manually set the power on the RF generator accordingly.
[0144] Handle
[0145] Referring again to FIGS. 21 and 22 , the handle 106 of the RF ablation device according to the second embodiment includes a distal grip section 142 and a proximal grip section 144 that are pivotally attached to one another at pivot pin 166 .
[0146] The proximal grip section 144 is coupled to the hypotube 122 ( FIG. 23 ) via yoke 168 , overload spring 170 and spring stop 172 , each of which is shown in the section view of FIG. 34 . The distal grip section 142 is coupled to the external hypotube 120 via male and female couplers 174 , 176 (see FIGS. 32A and 32B ). Squeezing the grip sections 142 , 144 towards one another thus causes relative movement between the external hypotube 120 and the internal hypotube 122 . This relative sliding movement results in deployment of the deflecting mechanism 102 b from the distal end of the sheath and expansion of the array 102 a to its expanded state.
[0147] Referring to FIGS. 32A and B, rack 180 is formed on male coupler 174 and calibration markings 182 are printed adjacent the rack 180 . The calibration markings 182 correspond to a variety of uterine lengths and may include lengths ranging from, for example, 4.0 to 6.0 cm in 0.5 cm increments.
[0148] A sliding collar 184 is slidably disposed on the tubing 108 and is slidable over male coupler 174 . Sliding collar 184 includes a rotating collar 186 and a female coupler 176 that includes a wedge-shaped heel 188 . A locking spring member 190 ( FIGS. 32B and 35 ) extends across an aperture 192 formed in the proximal grip 144 in alignment with the heel 188 . When the distal and proximal handle sections are squeezed together to deploy the array, the heel 188 passes into the aperture 192 . Its inclined lower surface gradually depresses the spring member 190 as the heel moves further into the aperture 192 . See FIGS. 36A and 36B . After passing completely over the spring member, the heel moves out of contact with the spring member. The spring member snaps upwardly thereby engaging the heel in the locked position. See FIG. 36C .
[0149] A release lever 194 ( FIG. 35 ) is attached to the free end of the spring member 190 . To disengage the spring lock, release lever 194 is depressed to lower spring member 190 so that the inclined heel can pass over the spring member and thus out of the aperture 192 .
[0150] Referring again to FIGS. 32A and 32B , sliding collar 184 is configured to allow the user to limit longitudinal extension of the array 102 a to a distance commensurate with a patient's predetermined uterine length. It does so by allowing the user to adjust the relative longitudinal position of male coupler 174 relative to the female coupler 176 using the rotating collar 186 to lock and unlock the female coupler from the rack 180 and the male coupler 174 . Locking the female coupler to the rack 180 and male coupler 174 will limit extension of the array to approximately the predetermined uterine length, as shown on the calibration markings 182 .
[0151] Once the uterine length has been measured using a conventional sound, the user positions sliding collar 184 adjacent to calibration marks 182 corresponding to the measured uterine length (e.g. 4.5 cm). Afterwards, the user rotates the collar section 186 to engage its internally positioned teeth with the rack 180 . This locks the longitudinal position of the heel 188 such that it will engage with the spring member 190 on the proximal grip when the array has been exposed to the length set by the sliding collar.
[0152] The handle 106 includes a pair of spring assemblies which facilitate controlled deployment and stowage of the array 102 a . One of the spring assemblies controls movement of the grips 142 , 144 to automatically stow the array 102 a into the sheath 104 when the user stops squeezing the grips 142 , 144 towards one another. The other of the spring assemblies controls the transverse movement of the spring flexures 124 to the expanded condition by limiting the maximum load that can be applied to the deployment mechanism 102 b.
[0153] FIG. 34 shows the distal and proximal grips 142 and 144 in partial cross-section. The first spring assembly for controlled stowage includes a handle return mandrel 196 that is slidably disposed within the proximal grip 144 . A compression spring 198 surrounds a portion of the return mandrel 196 , and a retaining ring 200 is attached to the mandrel 196 above the spring 198 . A spring stop 202 is disposed between the spring 198 and the retaining ring.
[0154] The lowermost end of the return mandrel 196 is pivotally engaged by a coupling member 204 on distal grip 142 . Relative movement of the grips 142 , 144 towards one another causes the coupling member 204 to pull the return member downwardly with the proximal grip 144 as indicated by arrows. Downward movement of the mandrel 196 causes its retaining ring 200 and spring stop 202 to bear downwardly against the compression spring 198 , thereby providing a movement which acts to rotate the grips 142 , 144 away from one another. When tension against the grips 142 , 144 is released (assuming that heel 188 is not locked into engagement with spring member 190 ) the grips rotate apart into the opened position as the compression spring 198 returns to the initial state, stowing the applicator head inside the sheath.
[0155] The second spring assembly for controlling array deployment is designed to control separation of the flexures. It includes a frame member 178 disposed over yoke 168 , which is pivotally attached to proximal grip 144 . Tubing 108 extends from the array 102 a (see FIG. 23 ), through the sheath 104 and is fixed at its proximal end to the frame member 178 . Hypotube 122 does not terminate at this point but instead extends beyond the proximal end of tubing 108 and through a window 206 in the frame member. Its proximal end 208 is slidably located within frame member 178 proximally of the window 206 and is fluidly coupled to a vacuum port 210 by fluid channel 212 . Hypotube 120 terminates within the frame. Its proximal end is fixed within the distal end of the frame.
[0156] A spring stop 214 is fixed to a section of the hypotube within the window 206 , and a compression spring 170 is disposed around the hypotube between the spring stop 172 and yoke 168 . See FIGS. 32B and 34 .
[0157] When the distal and proximal grips are moved towards one another, the relative rearward motion of the distal grip causes the distal grip to withdraw the sheath 104 from the array 102 a . Referring to FIGS. 37A and 37B , this motion continues until female coupler 176 contacts and bears against frame member 178 . Continued motion between the grips causes a relative rearward motion in the frame which causes the same rearward relative motion in external hypotube 120 . An opposing force is developed in yoke 168 , which causes a relative forward motion in hypotube 122 . The relative motion between the hypotubes causes deflection in flexures 124 , 136 which deflect in a manner that deploys and tensions the electrode array. Compression spring 170 acts to limit the force developed by the operator against hypotubes 120 , 122 , thus limiting the force of flexures 124 , 136 acting on the array and the target tissue surrounding the array.
[0158] Referring to FIG. 21 , collar 214 is slidably mounted on sheath 104 . Before the device is inserted into the uterus, collar 214 can be positioned along sheath 104 to the position measured by the uterine sound. Once in position, the collar provides visual and tactile feedback to the user to assure the device has been inserted the proper distance. In addition, after the applicator head 102 has been deployed, if the patient's cervical canal diameter is larger than the sheath dimensions, the collar 214 can be moved distally towards the cervix, making contact with it and creating a pneumatic seal between the sheath and cervix.
[0159] Second Exemplary Embodiment—Operation
[0160] In preparation for ablating the uterus utilizing the second exemplary embodiment, the user measures the uterine length using a uterine sound device. The user next positions sliding collar 184 ( FIG. 32B ) adjacent to calibration marks 182 corresponding to the measured uterine length (e.g. 4.5 cm) and rotates the collar section 186 to engage its internally positioned teeth with the rack 180 . This locks the longitudinal position of the heel 188 ( FIG. 32A ) such that it will engage with the spring member 190 when the array has been exposed to the length set by the sliding collar.
[0161] Next, with the grips 142 , 144 in their resting positions to keep the applicator head 102 covered by sheath 104 , the distal end of the device 100 is inserted into the uterus. Once the distal end of the sheath 104 is within the uterus, grips 142 , 144 are squeezed together to deploy the applicator head 102 from sheath 104 . Grips 142 , 144 are squeezed until heel 188 engages with locking spring member 190 as described with respect to FIGS. 36A through 36C .
[0162] At this point, deflecting mechanism 102 b has deployed the array 102 a into contact with the uterine walls. The user reads the uterine width, which as described above is transduced from the separation of the spring flexures, from gauge 146 . The measured length and width are entered into the RF generator system 250 ( FIG. 21 ) and used to calculate the ablation power.
[0163] Vacuum source 252 ( FIG. 21 ) is activated, causing application of suction to hypotube 122 via suction port 210 . Suction helps to draw uterine tissue into contact with the array 102 .
[0164] Ablation power is supplied to the electrode array 102 a by the RF generator system 250 . The tissue is heated as the RF energy passes from electrodes 118 a - d to the tissue, causing moisture to be released from the tissue. The vacuum source helps to draw moisture from the uterine cavity into the hypotube 122 . Moisture withdrawal is facilitated by the apertures 121 formed in flexures 124 by preventing moisture from being trapped between the flexures 124 and the lateral walls of the uterus.
[0165] If the RF generator 250 includes an impedance monitoring module, impedance may be monitored at the electrodes 118 a - d and the generator may be programmed to terminate RF delivery automatically once the impedance rises to a certain level. The generator system may also or alternatively display the measured impedance and allow the user to terminate RF delivery when desired.
[0166] When RF delivery is terminated, the user depresses release lever 194 to disengage heel 188 from locking spring member 190 and to thereby allow grips 142 , 144 to move to their expanded (resting condition). Release of grips 142 , 144 causes applicator head 102 to retract to its unexpanded condition and further causes applicator head 102 to be withdrawn into the sheath 104 . Finally, the distal end of the device 100 is withdrawn from the uterus.
[0167] Two embodiments of ablation devices in accordance with the present invention have been described herein. These embodiments have been shown for illustrative purposes only. It should be understood, however, that the invention is not intended to be limited to the specifics of the illustrated embodiments but is defined only in terms of the following claims. | An apparatus and method for use in performing ablation or coagulation of organs and other tissue includes a metallized fabric electrode array which is substantially absorbent and/or permeable to moisture and gases such as steam and conformable to the body cavity. The array includes conductive regions separated by insulated regions arranged to produce ablation to a predetermined depth. Following placement of the ablation device into contact with the tissue to be ablated, an RF generator is used to deliver RF energy to the conductive regions and to thereby induce current flow from the electrodes to tissue to be ablated. As the current heats the tissue, moisture (such as steam or liquid) leaves the tissue causing the tissue to dehydrate. Suction may be applied to facilitate moisture removal. The moisture permeability and/or absorbency of the electrode carrying member allows the moisture to leave the ablation site so as to prevent the moisture from providing a path of conductivity for the current. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-in-Part application of co-pending U.S. application Ser. No. 09/545,320 filed on Apr. 7, 2000.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure generally relates to a surgical apparatus for fusing adjacent bone structures, and, more particularly, to an apparatus and associated method for fusing adjacent vertebrae.
[0004] 2. Background of the Related Art
[0005] The fusion of adjacent bone structures is commonly performed to provide for long-term replacement to compensate for degenerative or deteriorated disorders in bone. For example, an intervertebral disc, which is a ligamentous cushion disposed between adjacent vertebrae, may undergo deterioration as a result of injury, disease, tumor or other disorders. The disk shrinks or flattens leading to mechanical instability and painful disc translocations.
[0006] Conventional procedure for disc surgery include partial or total excision of the injured disc portion, e.g., discectomy, and replacement of the excised disc with biologically acceptable plugs or bone wedges. The plugs are driven between adjacent vertebrae to maintain normal intervertebral spacing and to achieve, over a period of time, bony fusion with the plug and opposed vertebrae. More recently, emphasis has been placed on fusing bone structures (i.e., adjoining vertebrae) with metallic or ceramic prosthetic cage implants. One fusion cage implant is disclosed in commonly assigned U.S. Pat. No. 5,026,373 to Ray et al., the contents of which are incorporated herein by reference. The Ray '373 fusion cage includes a cylindrical cage body having a thread formed as part of its external surface and apertures extending through its wall which communicate with an internal cavity of the cage body. The fusion cage is inserted within a tapped bore or channel formed in the intervertebral space thereby stabilizing the vertebrae and maintaining a pre-defined intervertebral space. Preferably, a pair of fusion cages are implanted within the intervertebral space. The adjacent vertebral bone structures communicate through the apertures and with bone growth inducing substances which are within the internal cavity to unite and eventually form a solid fusion of the adjacent vertebrae. FIGS. 1 - 2 illustrate the insertion of a pair of the Ray '373 fusion cages positioned within an intervertebral space.
SUMMARY OF THE INVENTION
[0007] Accordingly, the present invention is directed to further improvements in spinal fusion procedures. In accordance with a preferred embodiment, an apparatus for facilitating fusion of adjacent bony structures includes an implant body dimensioned for positioning between adjacent bone structures to maintain the bone structures in desired spaced relation during interbody fusion. The implant body has an outer wall and an external threaded configuration disposed on the outer wall. At least one concave surface at least partially extends along the implant body. The concave surface advantageously reduces the transverse cross-sectional dimension of the implant member thereby facilitating placement of the implant member in restricted intervertebral areas. In addition, the concave surface enables placement of a pair of implants in nested side-by-side relation. Preferably, the threaded configuration has portions removed along an arc section of the outer wall thereby defining a series of generally longitudinally aligned concave surfaces in individual turns thereof. A system and method for facilitating fusion of adjacent vertebrae is also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Preferred embodiment(s) of the present disclosure are described herein with reference to the drawings wherein:
[0009] [0009]FIG. 1 is a view illustrating a portion of the vertebral column of a patient;
[0010] [0010]FIG. 2 is a view taken along line 2 - 2 of FIG. 1 illustrating a pair of prior art fusion implants positioned within the intervertebral space for fusion of adjacent vertebrae;
[0011] [0011]FIG. 3 is a perspective view of the fusion implant apparatus in accordance with the principles of the present disclosure;
[0012] [0012]FIG. 4 is a side plan view of the implant apparatus;
[0013] [0013]FIG. 5 is an axial view of the implant apparatus;
[0014] [0014]FIG. 6 is a side cross-sectional view of the implant apparatus taken along the lines 6 - 6 of FIG. 5;
[0015] [0015]FIG. 7 is an axial cross-sectional view of the implant apparatus taken along the lines 7 - 7 of FIG. 4;
[0016] [0016]FIG. 8 is a view illustrating details of the threaded configuration of the implant apparatus;
[0017] [0017]FIG. 9 is a perspective view of an alternate embodiment of the implant apparatus of FIG. 3:
[0018] [0018]FIG. 10 is an axial view of the implant apparatus of FIG. 9.
[0019] [0019]FIG. 11 is a perspective view of another alternate embodiment of the implant apparatus of FIG. 3; and
[0020] FIGS. 12 - 14 are views illustrating a preferred sequence of the implant apparatus within adjacent vertebrae.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] The preferred embodiment of the apparatus and method disclosed herein are discussed in terms of orthopedic spinal fusion procedures and instrumentation. It is envisioned, however, that the disclosure is applicable to a wide variety of procedures including, but, not limited to ligament repair, joint repair or replacement, non-union fractures, facial reconstruction and spinal stabilization. In addition, it is believed that the present method and instrumentation finds application in both open and minimally invasive procedures including endoscopic and arthroscopic procedures wherein access to the surgical site is achieved through a cannula or small incision.
[0022] The following discussion includes a description of the fusion implant utilized in performing a spinal fusion followed by a description of the preferred method for spinal fusion in accordance with the present disclosure.
[0023] In the discussion which follows, the term “proximal”, as is traditional, will refer to the portion of the structure which is closer to the operator while the term “distal” will refer to the portion which is further from the operator.
[0024] Referring now to the drawings in which like reference numerals identify similar or identical elements throughout the several views, FIG. 3 illustrates, in perspective, the fusion implant apparatus of the present disclosure. Fusion implant 100 is intended to be inserted within a preformed bore in adjacent bone structures, e.g., adjacent vertebrae, with the bore spanning the intervertebral space and penetrating the vertebral end plates.
[0025] Fusion implant 100 includes elongated implant body 102 which is preferably fabricated from a suitable biocompatible rigid material such as titanium and/or alloys of titanium, stainless steel, ceramic materials or rigid polymeric materials. Implant body 102 is preferably sufficient in strength to at least partially replace the supporting function of an intervertebral disc, i.e., to maintain adjacent vertebrae in desired spaced relation, during healing and fusion.
[0026] With reference to FIGS. 3 - 7 , implant body 102 includes exterior or outer wall 104 concentrically arranged about longitudinal axis “a” of the implant body 102 and inner cavity 106 within the exterior wall 104 . Implant body 102 is preferably substantially cylindrical in configuration defining a constant diameter along its length. Inner cavity 106 is intended to accommodate bone growth inducing substances such as bone chips taken from allograft or autograft, etc. . . . which facilitate the fusion process. Implant body 102 is preferably provided in various lengths ranging from about 18 mm-24 mm and in corresponding various diameters ranging from about 14 mm-18 mm. Other dimensions are also contemplated and may vary depending on the intended use of the implant in the cervical, thoracic or lumbar regions of the spine.
[0027] Outer wall 104 has an external threaded configuration 108 formed thereon. External threaded configuration 108 includes a uniform helical thread 110 which assists in advancing implant body 102 into a preformed channel provided in the adjacent vertebrae. In the preferred embodiment, thread 110 cooperates with an internally threaded bore within the adjacent vertebrae to advance implant body 102 within the threaded bore. Alternatively, thread 110 may be a self-tapping cutting thread, i.e., the thread is capable of deburring bone material during advancement into the performed channel thereby precluding the requirement of tapping the internal bore in the vertebrae.
[0028] A plurality of apertures 112 extend through outer wall 104 of implant body 102 . Apertures 112 are preferably formed by broaching grooves in the internal surface of the internal cavity 108 . The effect of such broaching is to remove material from the valleys between the individual turn of the thread 110 , thus defining the apertures 112 . The advantages of such an arrangement are disclosed in U.S. Pat. No. 4,961,740, the contents of which are incorporated herein by reference, and include immediate bone to bone contact between the vertebral bodies or bone structures and the bone inducing substances packed within the internal cavity 108 of the implant body 102 . Apertures 112 are preferably substantially the same in dimension although it is envisioned that the dimensions of the apertures may vary to provide for more or less bone to bone contact as desired.
[0029] As best depicted in FIGS. 4 and 7, apertures 112 are clustered about a transverse axis “t 1 ”, both at the upper and lower end of the axis. Consequently, apertures 112 come into contact with the upper and lower vertebral bone structures to encourage bone growth through implant body 102 from the vertebral bone structures when appropriately positioned within the vertebrae. The lateral sections of implant body 102 formed along transverse axis “t 2 ” do not have apertures in order to prevent growth of disk material which might interfere with the bone fusion process.
[0030] Outer wall 104 has a plurality of independent arcuate surfaces 114 defined in the outer wall and extending along the length of implant body 102 . The arcuate surfaces 114 are preferably concave in configuration and may be formed by grinding, blasting applications, etc. Preferably, concave surfaces 114 extend radially inwardly within each thread turn without penetrating or extending into the outer wall surface thereby defining removed portions of the thread as shown.
[0031] The concave surface arrangement provides two specific advantages. First, such arrangement increases the pull out or expulsion force necessary to remove the implant from the adjacent vertebrae. Secondly, the concave surface arrangement permits a pair of implants to be positioned in side by side relation within the adjacent vertebrae in a nested contacting relation. Moreover, the concave surface arrangement provides a reduced cross-sectional dimension along second transverse axis “t 2 ” relative to the cross-sectional dimension along first transverse axis “t 1 ” thereby facilitating placement of the implant body 102 within restricted vertebral locations.
[0032] Implant body 102 defines entry and trailing end faces 116 , 118 . End faces 116 , 118 are preferably open, i.e, having apertures 120 , 122 therein in communication with the inner cavity 106 . As best depicted in FIG. 6, implant body 102 has internal annular recesses 124 adjacent each end face 116 , 118 . Annular recesses 124 are intended to receive plastic end caps 126 (FIG. 3) which are received within the recesses in snap-fit relation therewith to enclose internal cavity 108 thereby retaining the bone growth inducing substances therein. Implant body 102 further includes tool receiving structure in the form of longitudinal extending internal rails 128 extending the length of the implant body 102 in diametrically opposed relation. Rails 128 receive correspondingly dimensioned prongs of an insertion instrument such that the insertion instrument may be rotated to cause corresponding rotation and entry of implant body 102 into the intervertebral space.
[0033] Alternate Embodiment(s)
[0034] FIGS. 9 - 10 illustrate an alternate embodiment of the implant apparatus of FIG. 3. This implant apparatus is substantially similar to the apparatus disclosed in FIG. 3, but, however incorporates a second series of concave surfaces 114 disposed in diametrically opposed relation to the first series. The second series provides flexibility to the user in terms of placement of the implant within the desired orientation within the intervertebral disc space. The second series also significantly reduces the cross-sectional dimension of the implant body along the second transverse axis “t 2 ”.
[0035] [0035]FIG. 11 illustrates an alternate embodiment of the implant apparatus of FIG. 3 where the concave surface extends through threaded configuration 110 and into exterior wall 104 thereby defining a single concave surface 114 ′ which extends along the length of implant body 102 .
[0036] Insertion of Fusion Implant
[0037] The insertion of the fusion implant 100 into an intervertebral space defined between adjacent lumbar vertebrae will now be described. The subsequent description will be particularly discussed in conjunction with an open posterior approach for spinal fusion implant insertion. However, it is to be appreciated that other approaches, e.g., anterior, lateral, posterior lateral, anterior lateral etc. . . . could be utilized. Laparoscopic approaches are also envisioned.
[0038] Initially, a first lateral side of the intervertebral space “i” is accessed utilizing appropriate retractors to expose the posterior vertebral surface. A drilling instrument is selected to prepare the disc space and vertebral end plates for insertion of the fusion implant. The cutting depth of drilling instrument may be adjusted as desired. The drilling instrument is advanced into the intervertebral space adjacent to the first lateral side to shear the soft tissue and cut the bone of the adjacent vertebrae thereby forming a bore which extends into the adjacent vertebrae adjacent the first lateral side as depicted in FIG. 12. With the first bore “b 1 ” drilled in the first lateral side, attention is directed to forming the bore in the second lateral side. With continued reference to FIG. 12, the second lateral side is accessed and the center entry point for the drill is identified. Preferably, the drill is positioned such that the second bore “b 2 ” will overlap the first bore “b 1 ”. The drill is activated to form the second bore. The first and second bores “b 1 , b 2 ” may be tapped with a conventional tap instrument if desired.
[0039] With reference to FIG. 13, a first implant 100 is packed with bone growth inducing substances as is conventional in the art. The fusion implant 100 may then be mounted on an insertion instrument (not shown) and advanced within the intervertebral space by rotating the implant 100 whereby threaded configuration 110 of the implant body 102 cooperates with the threaded bore to advance within the intervertebral space “i”. Preferably, the implant 100 is arranged such that concave surface generally extends along the axis “s” of the spine and faces the midline of the intervertebral space. If the implant of FIGS. 9 - 10 is utilized, the second series of concave surfaces facilitates placement of the implant 100 with the concave surface arrangement adjacent to the midline of the intervertebral space, i.e., when positioned, the implant need only be rotated a maximum of 90° in either direction to place the concave surface arrangement adjacent the midline. With the first implant positioned within the intervertebral space, a second implant “x” is implanted within the second threaded bore in the same manner. The second implant “x” is preferably a conventional cylindrical implant such as the implant disclosed in the Ray '373 patent. As appreciated, although the second bore overlaps the first bore, the clearance provided by the concave surface arrangement of the first implant 100 permits the second implant “x” to be advanced within the intervertebral space without interference. The second implant “x” is arranged such that the outer convex surface is received within the concave surface area of the first implant in nested side-by-side relation as shown. Thus, the concave surface arrangement permits two implants 100 , “x” to be placed in nested side-by-side arrangement. The concave surface arrangement also reduces the effective cross-sectional dimension of implant 100 thereby facilitating placement of the implants in a restricted vertebral location.
[0040] With reference to FIG. 14, it is appreciated that the second implant may be identical to implant 100 . When positioned within the adjacent vertebrae, the concave surface area may be facing the midline of the intervertebral space or alternatively adjacent the outer portion of the space as shown in phantom.
[0041] Implants 100 form struts across the intervertebral space “i” to maintain the adjacent vertebrae “V 1 , V 2 ” in appropriate spaced relation during the fusion process. Over a period of time, the adjacent vertebral tissue communicates through apertures 112 within implants 100 to form a solid fusion. Desirably, lateral vertebral tissue growth into the implant 100 is restricted due to the concave surface areas of the implant being devoid of apertures. Such lateral growth would inhibit the fusion process and potentially restrict subsequent spinal mobility.
[0042] While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the disclosure, but merely as exemplifications of preferred embodiments thereof. For example, the fusion implant 100 could also be used for thoracic and cervical vertebrae. Those skilled in the art will envision many other possible variations that are within the scope and spirit of the disclosure as defined by the claims appended hereto. | An apparatus for facilitating fusion of adjacent bony structures includes an implant body dimensioned for positioning between adjacent bone structures to maintain the bone structures in desired spaced relation during interbody fusion. The implant body has an outer wall and an external threaded configuration disposed on the outer wall. At least one concave surface at least partially extends along the implant body. The concave surface advantageously reduces the transverse cross-sectional dimension of the implant member thereby facilitating placement of the implant member in restricted intervertebral areas. In addition, the concave surface enables placement of a pair of implants in nested side-by-side relation. Preferably, the threaded configuration has portions removed along an arc section of the outer wall thereby defining a series of generally longitudinally aligned concave surfaces in individual turns thereof. A system and method for facilitating fusion of adjacent vertebrae is also disclosed. | 0 |
BACKGROUND OF THE INVENTION
[0001] Sensors that detect and measure the conductivity of fluids are useful for a variety of purposes. U.S. patent application Ser. No. 11/402,0062 by Guest, for example, offers a novel method and apparatus for controlling electrolytic processes purely through such conductivity measurements, rather than by the more traditional measurement of the pH or oxidation reduction potential of the electrolyzed product. While that invention offers a simpler and more reliable way to control such processes, a simpler—and thus implicitly more reliable—conductivity sensor would improve that innovation further, and be of great benefit in a variety of other applications, as well. Current sensors require complex circuitry and measurements, and are subject to degradation by the accumulation of deposits on sensor surfaces; also, when used to measure the conductivity of materials with low conductivity—such as water—they can see very low voltages at the receiver coil, resulting in inaccurate measurements overwhelmed by background “noise” from stray electromagnetic waves in the environment and similar. This invention has none of these drawbacks.
BRIEF SUMMARY OF THE INVENTION
[0002] In its simplest form, this invention consists of two rectangular magnetic cores joined together, like a digital readout rendering of the number eight. This figure eight is provided with a primary wire coil wrapped around the common member of the two cores, i.e., the central cross-bar of the eight, as well as two secondary wire coils, one to each core, wrapped around a section of the figure eight other than the common member. One core is at least partially immersed in or surrounded by the material whose conductivity is to be measured—the target material—and a voltage is applied to the primary coil—in practice, AC is generally preferred, but DC can also be advantageously used for certain applications, for example with target materials exhibiting high resistance. Measurement is achieved by one of three methods: either by measuring the signal of a secondary coil with the aid of an amplifier and analog circuits or by digital sampling and software calculation; by measuring the differential signal of the secondary coils with the aid of a differential amplifier or by digital sampling and software calculation; or else by connecting the secondary coils in series, and measuring the signal at the two ends of those series-connected coils.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0003] FIGS. 1A , 1 B, 1 C and 1 D show four views of the dual cores, as a single unit, as two unitary cores joined together, with the cores consisting of multiple pieces joined together, and as other than rectangles.
[0004] FIGS. 2A and 2B show a unitary dual core embodiment with coils wired in two variations.
[0005] FIGS. 3A , 3 B, 3 C, 3 D, 3 E, 3 F, 3 G, 3 H and 31 show a variety of embodiments, including different coil arrangements, the employment of magnetic sensors, single-core embodiments and a matrix employing more than two cores.
[0006] FIG. 4 shows a sensor according to FIG. 2B with one of its cores partially surrounded by a target material, and the other core not surrounded by such material.
[0007] FIG. 5 shows a sensor according to FIG. 2B with one of its cores partially surrounded by a target material, and the other core partially surrounded by another target material; in this illustration both target materials are fluids.
[0008] FIG. 6 shows an embodiment in which target material fluid is ducted around a wall of a core.
[0009] FIG. 7 shows the embodiment of FIG. 2B with an additional coil on each core, each such additional coil connected to a potentiometer for the purpose of balancing the magnetic flux of the two cores.
[0010] FIG. 8 shows an embodiment of this invention to measure resistance in an unknown circuit with the employment of a reference resistance.
[0011] FIG. 9 shows the employment of this invention to measure the level of a fluid.
[0012] FIGS. 10A and 10B show embodiments of the invention with the cores physically separated with no common member, connected only electrically.
DETAILED DESCRIPTION OF THE INVENTION
[0013] In its basic form, this invention comprises two magnetic cores joined together. While this shape is most easily conceived and described as a pair of rectangles joined to form a rectangular figure eight ( FIGS. 1A , 1 C and 1 D), is can readily be understood that these cores can effectively be made in a wide variety of shapes, and that they need not be identical to each other ( FIG. 1B ); the only requirement is that each of the cores describe a closed path.
[0014] Similarly, while FIG. 1A shows two unitary cores closely mated, it is possible to have these individual cores be composed of several parts ( FIG. 1C ).
[0015] In practice, barring unusual application requirements that would mandate the use of sensor cores in unusual shapes or comprised of multiple parts, it is particularly easy to produce, to use and, most certainly, to describe a one-piece rectangular figure eight sensor ( FIG. 1D ), though it can be readily understood how these descriptions apply to other variants, as well.
[0016] FIG. 2 shows the basic wiring arrangement. A joint or common electrical coil L 3 is wound around the common member, the cross-bar of the figure eight—what would be the area where, in a separate-core embodiment, the cores mate up. Furthermore, a first individual coil L 1 is wound around some portion of first core C 1 other than the common member, and a second individual coil L 2 is wound around some portion of second core C 2 other than the common member.
[0017] This wiring arrangement can be maintained as three separate coils, as in FIG. 2A , in which case the sensor operates by immersing one of the cores in the target material, optionally immersing the other core in a second target material, applying an electrical signal to common coil L 3 , and measuring the differential signal reading at individual coils L 1 and L 2 using an electronic circuit employing a differential amplifier or—and the irony in this phrasing is understood—its digital analog, digital sampling coupled with a software calculation.
[0018] In a preferred embodiment shown in FIG. 2B , individual coils L 1 and L 2 are connected in series. In this embodiment the sensor operates by immersing one of the cores in the target material, optionally immersing the other core in a second target material, applying an electrical signal to common coil L 3 , and measuring the signal at points C and D, the terminations of the joined individual coils L 1 and L 2 .
[0019] The scheme described in the two preceding paragraphs can also be reversed electrically: in the preferred embodiment by applying the electrical signal to points C and D on joined individual coils L 1 and L 2 , and by measuring the signal at points A and B on common coil L 3 , or in the earlier-mentioned embodiment by applying two signals which need not be identical, one each to individual coils L 1 and L 2 , and measuring the signal at common coil L 3 . The preferred embodiment is as described in the prior paragraph, and further descriptions will be of that embodiment, though it can be readily understood how they can be applied to the other embodiments mentioned.
[0020] The signal measurement taken may be simple voltage or current amplitude, or voltage or current phase, or any combination of these, as all will yield useful information about the conductivity of the target material. The measurements may be done in either time-domain or frequency-domain, using Discrete Fourier Transform (DFT) or Fast Fourier Transform (FFT).
[0021] While the most common application of this sensor will be for measuring the conductivity of fluids by immersing a core in a fluid, it is also possible to cast or build solid material around the sensor. It is also possible to use the sensor by having fluid target material ducted through a hose or pipe or similar conduit that passes through the magnetic path of one of the cores, e.g., a hose coiled around one of the sides of C 1 other than the common member, as shown in FIG. 6 . In much the same way, a solid target material could be placed in the magnetic path of one of the cores, e.g., a plastic rod encircling one of the sides of C 1 other than the common member.
[0022] It must be noted that this invention can also be practiced with conventional magnetic sensors (S 1 , S 2 , S 3 , etc.) in place of, or in addition to, the secondary coil(s) as signal receivers, as shown in FIGS. 3D , 3 E and 3 F. In such an application, the magnetic sensor(s) would be placed in holes or gaps in the cores and, of course, the transmitting coil—the coil to which the electrical signal is applied—need not be located on the common member, as in FIG. 3F , but can instead be located on one of the non-common sides of a core, as shown in FIGS. 3D and 3E .
[0023] Furthermore, the invention can be practiced with both fewer and more than two magnetic cores, as shown in FIGS. 3 G/ 3 H, and FIG. 31 , respectively. Again, it is possible to employ magnetic sensors instead of, or in conjunction with, receiving coils. While both single and more-than-two core embodiments are practicable, accuracy and sensitivity tend to suffer in the single-coil embodiment, and do not improve enough in the more-than-two core embodiment to make it generally attractive, so that the “sweet spot” and preferred embodiment for this invention is the dual-core iteration.
[0024] While it is generally helpful, effective and efficient for the cores to share a common member, it is not absolutely necessary. FIGS. 10A and 10B show embodiments with cores that are completely separate physically, connected only electrically. The wiring arrangement in FIG. 10A is analogous to that in FIG. 2A , and that in FIG. 10B is analogous to that in FIG. 2B ; as mentioned above, however, instead of series connection of L 3 - a and L 3 - b one may use an analog or digital circuit to control the magnetic flux of L 3 - a and L 3 - b.
[0025] The presence of a target material in the magnetic path of one or both cores C 1 and C 2 affects the signal reading as compared with the reading absent the target material. It can also be helpful to balance any differences in the baseline characteristics of the two cores by equipping one or both cores with at least one additional coil connected to a variable resistor, which can then be adjusted to equalize the magnetic flux of C 1 and C 2 , per FIG. 7 .
[0026] A further application of this invention is for measuring resistance, as shown in FIG. 8 . In this embodiment, a reference resistor would be connected to a coil on one core. The target material would be connected to another coil on the other core, and its resistance would affect the readings at receiver coils and/or magnetic sensors, permitting the resistance of the target material to be calculated. A similar structure can be used to measure the differential resistance of two unknown resistors.
[0027] This invention can also be used to measure the level of a fluid in a container, as shown in FIG. 9 . In this application, the core structure would be partially submerged in the target material fluid as shown, with the lower core completely submerged in the fluid, and at least part of the upper core not submerged. As the conductivity readings of the fluid would change as its level drops—or rises—the level can then easily be calculated. To obtain a greater range of level measurement and be able to measure the level closer to empty, it is advantageous to have the cores be asymmetrical, with the upper core taller than the lower core, as shown in FIG. 9 . This asymmetricality can distort readings, which distortion can be compensated for in a number of ways, for example by equalizing the magnetic flux of the cores as shown in FIG. 7 , by making the walls of the lower core correspondingly thinner, or by applying an equalizing algorithm to the readings. | A conductivity sensor, preferably a structure with a pair of magnetic cores with a primary coil wire around a shared member of both cores, and a secondary coil wire around a non-shared section of each core. When part of one core is immersed in a fluid and current is applied to the primary coil, measurements taken at the secondary coils reveal the conductivity of the fluid. The same structure can be used to measure the level of the fluid, and to determine impedance. | 6 |
TECHNICAL FIELD
[0001] The present invention relates to a vibration damper for a module installed on an aircraft nacelle.
BACKGROUND
[0002] A vibration damper is known from the prior art that is capable of being interposed between an electronic module and a fixed structure of an aircraft nacelle, comprising a block made of elastic material, a screw for fastening this block to said fixed structure, and means for fastening said module to said module to said block.
[0003] The electronic module typically may be a module for controlling various functions of the nacelle, such as the function for opening a portion of the nacelle for maintenance operations.
[0004] The vibration dampers make it possible to protect the electronic components of this module from the vibrations generated by the turbojet situated inside the nacelle.
[0005] When a blade of the turbojet breaks accidentally (a situation known to those skilled in the art under the abbreviation FBO, for “Fan Blade Out”), the vibrations generated by the turbojet reach very high amplitudes that may in particular lead to the destruction of the dampers and to the resulting separation of the electronic module from the fixed structure of the nacelle.
[0006] Such a separation is unacceptable because then the electronic module is likely to damage other members of the nacelle and of the engine.
[0007] In order to prevent such a separation, conventionally a safety yoke, which is fastened by its two ends to the fixed structure of the nacelle is placed over the damper.
[0008] Such a yoke makes it possible to keep the damper in place when it is destroyed under the effect of high-amplitude vibrations and thus to prevent the electronic module from being completely detached from the fixed structure of the nacelle.
[0009] Such a yoke and the fastenings associated therewith have a certain weight which runs counter to the constant search for weight reduction specific to the aviation field.
[0010] Moreover, such a yoke and its fastenings constitute additional parts which the maintenance technicians might forget to reinstall during replacement and/or maintenance operations.
BRIEF SUMMARY
[0011] A vibration damper is provided capable of being interposed between an electronic module and a fixed structure of an aircraft nacelle, comprising a block made of elastic material, a screw for fastening this block to said fixed structure, and means for fastening said module to said block, notable in that it comprises means for limiting the travel of said fastening means relative to said fastening screw in at least two directions of the space, these limiting means being dimensioned to prevent a strain on said screw that can lead to its fatigue and/or its breakage.
[0012] The presence of these travel-limiting means makes it possible, in the event of vibration rates of very high amplitude, to short-circuit the damping screw with respect to the transmission of the dynamic forces between the fixed structure of the nacelle and the electronic module, and thus avoid subjecting this screw to forces capable of leading to its breakage.
[0013] By virtue of these travel-limiting means, a damper is therefore obtained which is no longer likely to break in the event of vibration rates of high amplitude which may occur particularly at the time of an FBO (breakage of a turbojet blade) and during the time of the aircraft's return following the FBO.
[0014] According to other optional features of the damper according to the invention:
[0015] said limiting means are capable of limiting said travel in a plane perpendicular to said screw: these limiting means remove the risks of the screw shearing;
[0016] said limiting means are capable of limiting said travel in at least one direction of a line parallel to said screw;
[0017] said limiting means comprise on the one hand a dish capable of being fastened to said fixed structure, and on the other hand an impactor secured to said fastening means and positioned inside said dish, this dish and this impactor being separated in directions perpendicular and parallel to said screw by gaps such that the strain on said screw corresponding to the abutment of said impactor inside said dish is situated beyond the threshold of fatigue and/or of breakage of said screw: this embodiment with a dish and with an impactor makes it possible to obtain very simply a limitation of travel in the plane perpendicular to the screw and in the direction of a compression of the screw; the gaps are chosen so that no contact between the dish and the impactor is capable of changing the behavior of the damper in nominal stresses;
[0018] said impactor is coated with an elastomer on its face designed to interact with said dish: this coating limits the intensity of the impact between the impactor and the dish, in the event of these two parts butting against one another;
[0019] said block made of elastic material is formed like a double cone and said fastening means comprise a fastening washer held between the two cones of said double cone: this elastic block thus formed has great damping efficiency;
[0020] said impactor is mounted on said fastening means so as to sandwich a portion of said electronic module: this arrangement makes it possible to produce a robust connection of the electronic module with the damper;
[0021] this damper comprises a pull-out prevention stop: this stop makes it possible to limit the pulling out of the movable portion of the damper from the fixed portion at exceptional vibration rates.
[0022] The present invention also relates to an aircraft nacelle comprising a fixed structure and at least one electronic module mounted on this fixed structure by means of at least one damper according to the foregoing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Other features and advantages of the present invention will appear in the light of the following description and on examination of the appended figures in which:
[0024] FIG. 1 represents partially and in perspective an electronic module fastened to a fixed structure of an aircraft nacelle by means of a vibration damper according to the invention,
[0025] FIG. 2 represents a view in perspective of this damper,
[0026] FIG. 3 represents a view in perspective of the cup of this damper,
[0027] FIG. 4 represents in perspective the impactor of this damper; and
[0028] FIG. 5 is a view in axial section of the damper according to the invention, fastened respectively to the electronic module and to the fixed structure of the nacelle of FIG. 1 .
DETAILED DESCRIPTION
[0029] With reference now to FIG. 1 , a portion of an electronic module 1 can be seen which may comprise for example electronic components making it possible to control actuators of an aircraft nacelle.
[0030] These actuators may be used in particular to open movable portions of a nacelle during maintenance operations.
[0031] The fixed portion of this nacelle, that is to say the portion of this nacelle on which the movable portions are mounted, can be seen partially at 3 in FIG. 1 .
[0032] The electronic module 1 is fastened to the structure 3 by means of a plurality of dampers of which one 5 is shown in FIG. 1 .
[0033] With reference more particularly to FIGS. 2 to 4 , it can be seen that this damper comprises a screw 7 passing through, in this order, a pull-out prevention stop 9 , a block 10 made of elastic material, a fastening washer 11 , an impactor 13 and a cup 15 which may also be designated by the term “dish”.
[0034] With reference more particularly to FIG. 5 , it can be seen that the pull-out prevention stop 9 has the shape of a washer wedged against the head 17 of the screw 7 .
[0035] In its portion situated facing the fastening washer 11 , the pull-out prevention stop 9 comprises a rim 21 made of elastomer.
[0036] The screw 7 passes through a spacer 23 butting respectively against the head 17 of this screw and against the bottom of the cup 15 on which a centering rim 25 is arranged.
[0037] The spacer 23 defines a shoulder 27 and the block 10 made of elastic material is pinched between the pull-out prevention stop 9 and this shoulder 27 .
[0038] More particularly, the block 10 made of elastic material has the shape of a double cone, the two opposite-facing cones of which 10 a and 10 b pinch the fastening washer 11 .
[0039] This washer is itself fastened by at least two screws 29 a, 29 b to the impactor 13 , the electronic module 1 being sandwiched between this fastening washer 11 and this impactor 13 .
[0040] Preferably, this impactor 13 comprises, on its periphery, an elastomer coating 31 .
[0041] The impactor 13 , which is placed inside the cup 15 , as can be seen in FIG. 5 , is separated from this cup over the whole of its periphery by a first gap J 1 smaller than the gap J′ 1 separating the inside of the impactor 13 from the spacer 23 .
[0042] The cup 15 is secured to the structure 3 so that all the stresses due to the impacts of the impactor 13 are directly transmitted to this structure 3 .
[0043] It will be noted moreover that the bottom of the impactor 13 is separated from the bottom of the cup 15 by a second gap J 2 smaller than the gap J′ 2 separating the fastening washer 11 from the shoulder 27 of the spacer 23 .
[0044] The screw 7 passes through the fixed structure of the nacelle 3 to which it is fastened by means of a nut 33 .
[0045] The operating mode and the advantages of the damper which have just been described are a direct result of the foregoing.
[0046] In novel operating mode, that is to say when the vibrations of the nacelle do not exceed a predetermined threshold, these vibrations are transmitted by the fixed structure of the nacelle 3 to the electronic module 1 via the block 10 made of elastic material, the impactor 13 being able to move freely inside the cup 15 , both in the direction of the screw 7 and in a plane perpendicular to this screw.
[0047] When the vibrations of the fixed structure of the nacelle 3 exceed said predetermined threshold, for example following a blade breakage of the turbojet situated inside the nacelle (“Fan Blade Out”), the impactor 13 is capable of abutting the inside of the cup 15 either in the direction of the first gap J 1 , or in the direction of the second gap J 2 .
[0048] This abutment is damped by the elastomer coating 31 placed on the periphery of the impactor 13 .
[0049] This abutment allows a direct transmission, that is to say without passing through the screw 7 , of the dynamic forces from the cup 15 to the impactor 13 .
[0050] This in some way short-circuits the screw 7 , which makes it possible to prevent subjecting this screw to excessive bending and/or shearing and, to a lesser degree, compression forces capable of causing its fatigue and/or its breakage.
[0051] It will be noted that providing for the gaps J 1 and J 2 to be smaller respectively than the gaps J′ 1 and J′ 2 , ensures that the transmission of the dynamic forces in these extreme situations travels through the impactor and the cup 15 which are sized appropriately and incorporate damping properties and not through other more fragile parts of the damper such as the screw 7 .
[0052] The pull-out prevention stop 9 makes it possible to limit the travel of the fastening washer 11 in a direction that would lead to the pulling out of the block 10 made of elastic material. In this particular stress mode, the screw works in tension, its usual and preferred mode.
[0053] As can be understood in the light of the foregoing, the damper according to the invention makes it possible to ensure that, beyond a certain vibration threshold, the dynamic forces transmitted by the nacelle fixed structure 3 to the electronic module 1 no longer pass through the screw 7 , making it possible to prevent fatiguing and/or breaking this screw.
[0054] Naturally, the sizing of the gaps J 1 and J 2 is carried out according to the mechanical characteristics of the screw 7 according to conventional methods within the scope of those skilled in the art.
[0055] In other words, these gaps J 1 and J 2 are big enough to allow normal operation, that is to say resting on the elasticity of the block 10 , in the normal vibration ranges, and small enough to ensure a direct transition of the dynamic forces between the cup 15 and the impactor 13 in the event of exceptional vibrations.
[0056] Because of the presence of a means for limiting the travel of the movable portion of the damper relative to its fixed portion, any risk of destruction of the screw 7 is prevented at exceptional vibration rates, and so it is no longer necessary to provide additional security means such as a yoke (as was the case in the prior art) in order to prevent the risk of the electronic module 1 detaching from the nacelle fixed structure 3 .
[0057] Naturally, the present invention is in no way limited to the embodiments described and shown which are provided simply as examples. | The invention relates to a vibration damper ( 5 ) that can be provided between an electronic housing ( 1 ) and the fixed structure of an aircraft nacelle ( 3 ). It comprises a block of an elastic material ( 10 ), a screw ( 7 ) for securing the block ( 10 ) to fixed structure ( 3 ), and means ( 11, 29 a, 29 b ) for securing said housing ( 1 ) onto said block ( 10 ). It is characterised in that it comprises means ( 13, 15 ) for limiting the travel of said attachment means ( 11, 29 a, 29 b ) relative to said securing screw ( 7 ) in at least two directions of the space, wherein the limitation means ( 13, 15 ) are sized so as to prevent any strain on the screw ( 7 ) that could lead to the fatigue and/or breakage thereof. | 5 |
The present invention concerns a selection box for a home knitting machine having one or two straight needle bed members in which are formed channels for slidably receiving needles. The needles are actuated by cams carried by a knitting carriage which is moved with a reciprocating translatory movement on the needle bed members. Selection of the needles is effected by selection units mounted at the entry of the cam tracks of the carriage, the selection units comprising inter alia electromagnets which receive electrical pulses from the selection box. The aim of this action is to move the needles into different positions so as to be actuated by different tracks of the knitting carriage, in order to produce different knitting stitches, including jacquard.
There are many processes for programming the selection of the needles of a knitting machine, in particular matrixes of stud or diode type, program card reading means of all kinds, and magnetic tape reading means, etc. The principle of such processes is always the same and comprises the provision on a carrier of the successive data which are to be transmitted to the needles, generally by electromagnetic means, in order to produce the desired knitting stitch. Such data may either be taken from the program and directly transmitted to the electromagnetic means for carrying out the selection operation, this occurring in synchronism with the forward feed movement of the carriage, or stored in a memory from which they are taken, the latter process being more burdensome for their reason. In all cases, the size of the pattern or motif which can be knitted, when the selection operation is used for producing jacquard knitting, depends on the amount of data which can be carried by the carrier.
Program cards have the advantage, as information carriers, that they give an image which is representative of the pattern to be produced, while being easy for the user to program. In order to read such cards, when an optical reading means is used, it is sufficient to provide regions in which the light is for example reflected and other regions in which the light is not reflected, which can be achieved for example by black marks, in such a way that a needle of the knitting machine corresponds to each such region.
This has obviously led manufacturers to produce checked or squared program cards, wherein each elementary square contains the piece of data relating to a given needle of the knitting machine.
In this case, the definition of the piece of data is perfect but the process does not make it possible to produce patterns whose width is that of the knitting machine, while using a program card of acceptable size, that is to say, an A4 size, or else the marks made on the cards must be so fine that programming by the operator of the machine would become a real problem by virtue of the extreme attention to minute detail which would have to be applied in carrying out the programming operation.
This limitation has led certain manufacturers of knitting machines which use a squared program card to use memories in which the data on the card are stored, then treating such data in order to produce multiplication thereof by a constant number.
This process which is already burdensome in itself suffers from two major disadvantages: firstly, the outlines of the pattern are formed by a step-like configuration whose steps are equal, at a minimum, in regard to the number of stitches and rows, to the multiplying number, and the errors and defects in the proportions of the pattern are magnified, as the process does not take account of the length of the stitches. Indeed, there is not a constant proportion between the number of rows for ten cm of knitting and the number of stitches for ten cm of the same piece of knitting; this proportion varies in dependence on the thread, the kind of stitch, the length of the stitches etc.
The aim of the present invention is to remedy these various disadvantages, and the invention seeks to provide an inexpensive solution to the problem of producing patterns which must be strictly defined, to retain the proportions of a pattern whose width is that of the bed of needles of the machine for example, in this latter case, to provide a degree of definition of the outline of the pattern which is to within a stitch, and to be easily programmable.
For this purpose, the present invention concerns a home knitting machine comprising at least one straight needle bed member provided with grooves slidably receiving the knitting needles, a carriage which is movable on the needle bed member and which is provided with selection units and cam tracks for actuating and displacing the needles of the needle bed member, a programming installation comprising reading means which are electrically connected to the selection units and which are relatively movable with respect to a program card, means for relatively displacing, from one row to the next, the reading means with respect to the program card, mechanical means for connecting the programming installation to the carriage for successive reading of the rows of the program card by the reading means in synchronism with the movement of the carriage, the machine being characterised in that the means for relatively displacing from one row to the next the reading means relative to the program card comprise means for adjusting the pitch of the scanned rows of the card.
In accordance with another feature of the invention, the connecting means for mechanically connecting the programming installation to the carriage comprise a speed selecting means.
According to another feature of the invention, the means for connecting the installation to the carriage comprise a disconnection means.
According to another feature of the invention, the programming installation comprises a plurality of sensing means for reading the program card, the sensing means being mounted at regular spacings on an endless belt.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated by way of non-limiting example in the accompanying drawings in which:
FIGS. 1 and 2 show the program cards which can be used, FIG. 3 shows a diagrammatic view of the means for advancing the pin wheels,
FIG. 4 shows a diagrammatic view of the drive of the ratchet wheel by the pawl,
FIG. 5 shows a diagrammatic view of the mounting of the sensors on the toothed belt,
FIG. 6 is a diagrammatic view of the means for driving the sensors and the drive for the disc giving the associated design,
FIG. 7 shows a detail of the disc giving the associated design, and
FIG. 8 is a diagrammatic view showing the connection between the drive for the sensors and the drive for the slider by the knitting carriage.
DETAILED DESCRIPTION
The knitting machine according to the invention associates two possibilities in a single box housing, one possibility consisting of repetitive reading of a squared program card comprising marks of contrasting colours, for example black and white, which are related to the pattern to be produced, such data being directly treated and converted for energisation or non-energisation of the coils of the electromagnets of the selection units of the knitting carriage. There is therefore no storage memory.
This first form of programming will be used for knitting patterns which are geometric or otherwise and which are repeated or not repeated, but which must be strictly defined, the size of the patterns being a fraction of the total number of needles which can normally be used, which fraction is such that it permits easy programming by the user of the knitting machine.
The second possibility consists of reading of a program card of the same format as above, but which does not have any squaring, the program being quite simply formed by an artistic design produced in contrasting colours on the program card. At the moment of selecting a certain needle, the optical reader is moved before the program card in synchronism with the knitting carriage but at a reduced speed, in such a way that the knitting carriage moves in front of all the needles of the knitting machine when the reading means, which is moved over the total working width of the program card, is interrogated in regard to its conduction state, according to whether it is disposed opposite a portion which does or does not reflect light. This information is then treated as above for energisation or non-energisation of the coil of the electromagnet of the selection unit of the carriage.
This possibility is used for producing patterns of very great width, which may be the total width of the knitting machine, while providing outlines which are in accordance with reality.
Linked with this possibility of using two program cards is the possibility of having two different types of advance movements for the program cards. When the program card is squared, the advance movement of the program card must be such that it brings a fresh row of data in front of the optical reader, for each successive row of knitting. As all the program cards have the same squared pattern thereon, a constant advance movement which is equal to the vertical pitch of the squares is both necessary and sufficient.
When the program card is not squared and therefore the program is formed by an artistic design, the advance movement of the program card must be such that the proportions of the design are observed, in the course of the knitting operation. For this purpose, the advance movement of the program card is controllable in dependence on the ratio to be observed between the number of stitches for a ten cm width and the number of rows for a ten cm height of a sample pattern of knitting produced with the same thread, the same adjustments and the same kind of stitch, as those of the article to be knitted.
FIG. 1 shows a squared program card, the pattern being illustrated by the blackened elementary squares which form the pattern. Row after row, the advance movement of the program card will bring the successive rows of squares into a position to be read by the photoelectric sensors.
FIG. 2 shows a program card which is not squared, the pattern being an artistic design. In this case, the advance movement of the program card will be such that the proportions of the pattern will be observed in the knitting operation. For this purpose, it will be necessary first of all to knit a sample pattern under the conditions in which the final article will be produced, to establish the proportion between the number of stitches and the number of rows for the same dimension, and, from this proportion, to deduce the advance movement which the program card will be required to carry out, for the successive rows of knitting.
FIG. 3 shows a diagrammatic view of the means for controlling the advance movement of the program card, row after row. The motor 12 is associated with a pulse control means and a circuit for self-supply of the motor during a revolution. The motor 12 is fixed to a casing box 1 in which there is disposed a pawl carrier 2 which is fixed with respect to the motor shaft, a ratchet wheel 3 which is capable of free rotary and translatory movement on the motor shaft, which ratchet wheel 3 meshes with pinions 9, 10 and 11 to cause rotation of the shaft on which the pin wheels for driving the program card are mounted. By means of the control shaft 8 which can be moved manually into two positions, the ratchet wheel 3 may occupy as a first axial position or upper position in which the ratchet wheel 3 is locked by direct coupling to the pawl carrier 2 by the locking fingers 2 1 . It is then fixed for rotational movement with the motor 12 and is rotated through 360°, in each control step for the advance movement of the program card. After reduction by means of the pinions 9, 10 and 11, the above-mentioned 360° rotary movement is that which must be imparted to the pin wheels in order to move the squared program card from one row of squares to another. In a second axial position or low position (shown on FIGS. 3 and 4), the ratchet wheel 3 is freely rotatable but may perform a toothwise advance movement, by means of the pawl 4 carried by the pawl carrier 2. This advance movement is determined by the use of two cams, one being a fixed cam 6 which uncovers a maximum number of teeth on the ratchet wheel 3 and the other being a movable cam 5 which is fixed with respect to a lever 7 which is manually operable, thereby making it possible to prevent the pawl 4 from acting on a selected number of teeth of the ratchet wheel, which are normally left in the operative position by the fixed cam 6. This combined action of the two cams 5 and 6 permits adjustment of the rotary movement of the ratchet wheel 3 and consequently of the pin wheels for driving the program card. This possibility is used for controlling the advance movement of the non-squared program card, and therefore the pitch of the rows, in order to knit the pattern design which is carried thereon, artistically and in the proper proportions.
FIG. 4 shows a detail of the control of the ratchet wheel 3 by the pawl carrier 2 on which the pawl 4 is mounted, with a spring loading. FIG. 4 also shows the manner in which the cam 6 leaves exposed a given number of teeth (seven teeth on FIG. 4) of the ratchet wheel 3, and how the movable cam 5 which rotates about the fixed cam 6 completes the action of the fixed cam 6, by preventing the pawl 4 from acting on a controllable number of teeth of the ratchet wheel 3.
FIG. 5 shows the mounting of the sensors 13 at regular spacings on the toothed belt 14 which is driven in rotation by the drive pulley 15 and which passes around the idle pulley 15'. The distance between two successive sensors must be equal to the total distance between the marks on the program card 42.
FIG. 6 shows the means for driving the drive pulley 15 which drives the sensors 13 by way of the toothed belt and the idle pulley 15'. The drive pulley 15 is fixed on the shaft 16 which is itself fixed with respect to the dog clutch carrier 17. Pivotally mounted on the carrier 17 are two levers 18 comprising two arms which form between them an angle which depends on the two ratios to be provided and which are provided at each of their ends with a tooth whose shape is adapted to that of the teeth of the hollow gears into which they may engage.
A ring 19, which is slidable on the levers 18, may occupy one of three positions 19', 19" and 19"'. In position 19', the ring 19 presses the levers 18 by way of springs 20 and forces them into engagement with the hollow pinion 22 of the wheel 24, causing the teeth to bottom against each other, to eliminate play. As the hollow pinion 22 is fixed with respect to the shaft 23, with movement being imparted to the shaft 23 by the knitting carriage, the shaft 16 is now directly fixed with respect to the shaft 23 and rotates at the same speed. This possibility is used for controlling the sensors for reading squared program cards and, when the knitting carriage is displaced by the distance between two needles, the sensors are displaced by the distance between two sucessive squares of the squared program card. As, in order to permit easy programming of the program card by the user of the machine, the number of marks carried by the program card is lower than the number of needles of a needle bed member of the knitting machine, each sensor provides for reading of the program card successively when the knitting carriage is displaced over the whole length of the needle bed of the knitting machine, until all the data required have been supplied so causing on the width of the knitting machine, the knitting of a number of pattern or motif which correspond to the number of sensors reading the program card.
In position 19"', the ring 19 presses the levers 18 by way of the springs 20 and forces them into engagement with the hollow pinion 21, the shaft 23 driving the pinion 24 which, by way of the countershaft assembly comprising the pinions 25 and 27 which are fixedly mounted on the shaft 28, drives the pinion 29 which is fixed with respect to the pinion 21 which is normally free on the shaft 16 but which is fixed with respect thereto by way of the levers 18 which are fixed with respect to the carrier 17 which is itself fixed with respect to the shaft 16. The shaft 16 is thus driven in rotation by way of the pinions 24, 25, 27 and 29. This transmission assembly makes it possible to achieve a reduction between the movement of the sensors and the movement of the carriage. This reduction is so calculated that a single sensor reads the program card when the carriage is displaced over all the needles of the knitting machine. This possibility is used for reading non-squared program cards, on which the pattern to be produced is drawn in an artistic fashion, while knitting of the pattern can be effected over the total width of the knitting machine.
If the ring 19 is in position 19", the levers 18 do not engage with either of the pinions 21 and 22 and consequently there is no longer any rotary connection between the shaft 23 and the shaft 16. This position is the neutral position and is used for positioning the pattern. Indeed, if one of the sensors is at the beginning of the pattern on the program card when the carriage is opposite the Xth needle, it is obvious that, on moving into position 19' or 19", the above-mentioned Xth needle will be the first needle of the pattern.
FIG. 6 also shows the means which make it possible to associate a second pattern with that of the program card. An arm 30 on a sleeve 31 is mounted on the shaft 28 and is fixed for rotation therewith. The arm 30 entrains the disc 26 which comprises tapered recesses which are disposed, for example, every two steps or pitches of the needles on the needle bed. The recesses are read by a sensor 38 in order to form a cyclically operable circuit-breaker switch which is operated synchronously with the carriage of the machine and which is incorporated in the electrical circuit connecting the reading sensors 13 and the selection units. The cyclically operable switch thus controls the selection operation at one needle in two, independently of the selection determined by the program card reading means. A circuit-breaker switch 38 1 mounted on the circuit of the sensor 38 can render it inoperative. The arm 30 has a capacity for pivotal movement inwardly of the disc, corresponding to one pitch or step, in order thereby to produce a reversal of the selection when there is a change in the direction of translatory movement of the knitting carriage and consequently a change in the direction of rotation of the disc 26.
FIG. 7 is a front view of part of the disc 26, showing the detail of its recesses.
FIG. 8 is a diagrammatic view showing the connection between the slider 36 which is fixed with respect to the knitting carriage 39 in its translatory movement above the needle bed 40 of the knitting machine provided with the knitting needles 41, and the sensors 13. The slider 36 is fixed to a perforated strip 35 driving the pin wheels 37 and 34. The pin wheel 34 is non-rotatably fixed on the shaft 33 and transmits its rotary movement by way of a shaft 32 to the output shaft 23 of the selection box. When the ring 19 is in the position 19", that is to say, its neutral position, the marker 36' on the slider 36 may be positioned opposite any needle of the knitting machine, without the sensors 13 of the box being themselves displaced. If one of the sensors 13 has its marker 13' opposite the first pattern instruction of the program card, and if the ring 19 is moved into one or other of the positions 19' and 19"', in both cases the needle opposite the marker 36' of the slider 36 will be the needle at which knitting of the pattern of the program card will be begun. | This invention concerns a home knitting machine comprising at least one straight needle bed member provided with grooves slidably receiving the knitting needles, a carriage which is movable on the needle bed member and which is provide with selection units and cam tracks for actuating and displacing the needles of the needle bed member, a programming installation comprising reading means which are electrically connected to the selection units and which are relatively movable with respect to a program card, means for relatively displacing, from one row to the next, the reading means with respect to the program card, mechanical means for connecting the programming installation to the carriage for successive reading of the rows of the program card by the reading means in synchronism with the movement of the carriage, this machine being characterized in that the means for relatively displacing from one row to the next the reading means relative to the program card comprise means for adjusting the pitch of the scanned rows of the card. | 3 |
PRIORITY
This application claims priority from prior provisional application Ser. No. 60/446,201 filed Feb. 11, 2003 the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to optical fibers and systems containing such optical fibers, and, in particular, to cladding-pumped waveguide and fiber lasers and amplifiers.
BACKGROUND OF THE INVENTION
Cladding pumped (also called double-clad) fiber lasers and amplifiers are good converters of low brightness radiation from laser diodes to a high brightness single-mode radiation. All-fiber construction and the robust monolithic design provide good stability and excellent beam quality thereby making fiber lasers a unique source for many industrial, military, scientific and medical applications.
A typical cladding-pumped fiber comprises a single-mode (or a few mode) core doped with rare-earth ions and a plurality of cladding layers supporting multi-mode pumping light. The inner cladding surrounding the core is typically a silica cladding with a large cross section compared to that of the core. The outer cladding is typically a low-index polymer cladding, or fluorinated silica cladding, or air-silica structure with an effective refractive index less than that of the inner cladding providing a large numerical aperture and guiding properties for the inner cladding. Light from low brightness multimode optical sources such as single laser diodes or diode arrays can be coupled into the inner cladding due to its large cross sectional area and high numerical aperture. Propagating in the inner cladding pumping light is absorbed by the rare-earth ions in the core providing amplification for signals in the single-mode core. With an optical feedback provided by spectrally selective mirrors from both fiber ends (so called linear cavity) the cladding-pumped fiber becomes a laser oscillator at the selected wavelength. Absorption of the pump light in the core depends on the geometry of the fiber and is roughly proportional to the core area-to-inner cladding area ratio. The larger inner cladding area the smaller absorption coefficient at a fixed core area.
A variety of schemes have been suggested for coupling low brightness sources into the inner cladding efficiently. The most common among them are side coupling using a multimode fiber (see, for example, U.S. Pat. No. 5,999,673), etching pits into the double-clad fibers, coupling through a multimode fiber being in optical contact with a doped fiber with parallel surfaces, coupling through a tapered fiber bundle with/or without single mode fiber in the center of the bundle (see, for example, U.S. Pat. No. 5,864,644). All these techniques except the last one permit separation of the signal path of the single-mode core from the pump-launching path which is very important for fiber amplifiers. No technique has been suggested for de-coupling of the pump power from a cladding. The reason is that most of fiber lasers operate in a linear cavity design (Fabry-Perot cavity with two mirrors) and the length of the cavity is typically chosen to absorb more than 90% of the pump power. The length of fiber amplifiers is also optimized to reduce residual pump power to less than 10%. A linear cavity design works well up to laser powers of 100 W. However, with increased pump power handling the residual power becomes an issue.
A major difficulty preventing scaling fiber lasers to high output powers for example, hundreds of watts or kilowatt level, is an efficient coupling of a sufficient number of low brightness sources into the inner cladding. An increase in the cladding area results in a longer pump absorption length and a longer cavity length. In turn, a longer cavity length give rise to nonlinear effects such as Stimulated Raman scattering and stimulated Brillouin scattering that limit the output power of the system. The cavity length can be shorter if a pump-reflecting mirror is placed at the end of the cavity. However, residual pump light reflected from the output coupler in short fibers would likely damage the laser diode pump source.
An alternative to the pump-reflecting mirror is a ring cavity where pump light circulates in the cavity. However, for double-clad fibers there is no an appropriate fiber wavelength-division-multiplexer for constructing a ring cavity, as can be done with single-mode fibers. Use of bulk multiplexers requires polarization control, which is also difficult to achieve in double-clad fibers. The prior art solution for the ring cavity includes a 45° angle-polished fiber output end placed in front of the input end that can re-launch both the signal and pump power into the fiber. This scheme uses bulk elements and requires a number of fine interfaces with associated problems of matching and alignment. As a result, the demonstrated efficiency was lower than in the traditional linear cavity. Accordingly there is a need for a new robust and compact all-fiber design for a cavity with a re-circulating pump.
Another difficulty related to the typical linear cavity design of cladding-pumped fiber lasers is the problem of short wavelength generation in the fluorescence spectrum of fiber lasers. Typically, rare-earth ions in silica exhibit quite broad fluorescence spectrum. For example, fluorescence spectrum of Yb-doped fiber extends from 1020 nm to 1180 nm with a strong separate peak at 976 nm. However, it is very difficult to get efficient generation in the short wavelength part of the spectrum, and especially at 976 nm. The reason is that many rare-earth ions (for example, Tm, Yb, Er at 1535 nm, Nd at 900–940 nm) provide three-level lasing systems. In a three-level system, the lasing occurs from an excited level to either the heavily populated ground state or a closely spaced level separated from it by no more than a few kT. The significant thermal population of the lower lasing level results in re-absorption of light at the laser wavelength. The effect of re-absorption is much stronger at shorter wavelengths because of a smaller energy separation between the lower laser level and the ground state. For three-level or quasi-three-level systems the long cavity length will result in considerable re-absorption and therefore lead to a high threshold and a low efficiency. To reduce re-absorption, an intense pump power should be maintained in the fiber to keep the population inversion relatively high. However, it is difficult to fulfill this requirement for a linear cavity in the whole fiber without loss of conversion efficiency. Thus, a short ring cavity with a re-circulating pump would help to generate light at the short wavelength side of the broadband spectrum for three-level and quasi-three-level transitions.
The Y-doped fiber lasers generating at short wavelengths of their fluorescent spectrum in the range 976–1060 nm attract a lot of attention as a promising pump source for high-powered erbium-doped fiber lasers and amplifiers (1530–1630 nm) or as a pump for Pr-doped lasers and amplifiers (1310 nm region). Using a fiber Raman laser, light from the wavelength region of 980–1060 nm can be efficiently converted to the output wavelength from 1.1 to 1.7 micron. New industrial and military applications also require high power systems at wavelengths near 1 micron. High electrical-to-optical conversion efficiency is very important for many of those applications. Typical Yb-doped fiber lasers at 976–980 nm have a reduced cladding area to shorten the pump absorption length to less than a meter. However, reduction of a cladding diameter automatically results in a less coupled pump power from laser diodes. In the other approach, the core diameter can be increased along with a proportionally reduced a numerical aperture of the fiber. The maximum core diameter is limited by the requirement of single-mode propagation in the core and enhanced bending loss in low numerical aperture fibers. The latter approach along with a requirement to maintain a high pump power density along the fiber may provide an efficient way for high power generation in Yb fibers. The same considerations are valid for three-level transitions in fibers doped with Nd, Er, Tm and other ions. Clearly there is a need to find a more efficient method to generate a high optical power in rare-earth ion-doped fiber lasers at three-level and quasi-three-level transitions.
SUMMARY OF THE INVENTION
In one aspect, an apparatus in accordance with the present invention comprises an amplifier fiber having a doped core surrounded by a cladding. The core doping provides optical gain for light propagating therein when the doped core is energized by pump light absorbed in the core. An optical pumping arrangement for the amplifier fiber includes one or more transmission fibers. The optical arrangement is configured to insert pump-light from a source thereof into the amplifier fiber cladding such that the pump light propagates in the cladding. The optical arrangement is further configured to receive an unabsorbed portion of the propagated pump light from the cladding, and re-insert the unabsorbed portion of the pump-light into the cladding for re-propagation therein.
The inventive apparatus is particularly useful for pumping lengths of amplifier fiber that are too short to allow all of the pump light propagating in the cladding to be absorbed in the amplifier fiber core in a single pass through the fiber. Extracting and re-inserting unabsorbed pump light makes use of pump light that would otherwise be wasted.
In one preferred embodiment, the optical pumping arrangement includes a plurality of N+M, transmission fibers. Ends of all of the N+M transmission fibers are formed into a first composite fiber or multiplexer having a diameter about equal to the diameter of the amplifying fiber. The first composite fiber is coupled to an input end of the amplifying fiber. Opposite ends of N of the transmission fibers are formed into a second composite fiber also having a diameter about equal to the diameter of the amplifying fiber. The second composite fiber is coupled to an input end of the amplifying fiber. Pump light is inserted from the pump light source into the amplifier cladding via one or more of the M fibers, and is received from the amplifier cladding and reinserted into the amplifier cladding via one or more of the N fibers.
This embodiment is particularly useful for optically pumping an amplifier with light from a plurality of diode-laser emitters. By way of example, light from each of M emitters can be directed into a corresponding one of the M fibers. Other aspects and embodiments of the present invention will be evident to those skilled in the art for the detailed description of the invention presented hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a schematically illustrates a prior-art pumping arrangement for a fiber laser including a plurality of optical fibers delivering pump light, the plurality of being bundled, tapered, and fused into a single multimode fiber spliced onto an end of the fiber laser to deliver pump light longitudinally into the fiber laser.
FIG. 1 b schematically illustrates a prior-art pumping arrangement for a fiber amplifier including a plurality of optical fibers delivering pump light, each of the fibers being fused together with the cladding of the fiber amplifier to deliver pump light longitudinally into the cladding of the fiber amplifier.
FIGS. 2 a – 2 b schematically illustrates a lateral coupling arrangement for pumping a fiber amplifier or a fiber laser wherein at least one optical fiber delivering pump light is fused into the cladding of the fiber to form a fused region tapering to the diameter of the fiber amplifier or fiber laser.
FIG. 3 a schematically illustrates a fiber laser including a plurality of pump light sources delivering light to a corresponding plurality of optical fibers in the arrangement of FIGS. 1 a – 1 b.
FIG. 3 b schematically illustrates a fiber laser including a plurality of pump light sources delivering light to a corresponding plurality of optical fibers in the arrangement of FIGS. 2 a – 2 b.
FIG. 4 schematically illustrates a fiber laser similar to the laser of FIG. 3 a but wherein there are two pluralities of pump light sources delivering light to a corresponding two pluralities of corresponding multimode fibers, with one plurality of multimode fibers delivering pump light to one end of the fiber laser, and the other plurality of multimode fibers delivering pump light to an opposite end of the fiber laser.
FIGS. 5 a – 5 b schematically illustrate one preferred arrangement in accordance with the present invention for coupling pump-light out of the cladding of a fiber laser or fiber amplifier into one or more optical fibers.
FIGS. 5 c – 5 d schematically illustrate preferred arrangements in accordance with the present invention for coupling pump-light out of the cladding of a fiber laser or fiber amplifier into a fused bundle of optical fibers.
FIGS. 6 a – 6 c schematically illustrate preferred arrangements in accordance with the present invention wherein a single fiber is used for coupling pump-light out of the cladding of a fiber laser or fiber amplifier and re-coupling the out-coupled pump light back into the cladding of the fiber laser or fiber amplifier.
FIGS. 7 a – 7 e schematically illustrate a fiber amplifier and fiber lasers in accordance with the present invention wherein there are six pump-light input fibers two of which are supplied by pump light sources and the remaining four of which are supplied with pump light by four fibers arranged to couple the pump light out of the fiber laser or amplifier in accordance with the present invention.
FIG. 8 schematically illustrates a fiber laser in accordance with the present invention similar to the arrangements of FIGS. 7 a–e but wherein a lenses are used to couple pump light from the input fibers into the fiber laser and to deliver pump light from the laser to the out-coupling fibers.
FIG. 9 schematically illustrates a fiber amplifier optically pumped by a plurality of fiber lasers in accordance with the present invention.
FIG. 10 a schematically illustrates inventive apparatus for delivering light from a source via an arrangement of optical fibers to an optical amplifier, the optical fiber arrangement including a length of fiber sufficient to convert the source light to light having a Stokes shifted wavelength before it is delivered to the optical amplifier, and including a fiber optical isolator between the source and the Stokes shifting fiber to attenuate any Stokes shifted light reflected from the optical amplifier back along the fiber arrangement into the source.
FIGS. 10 b – 10 e schematically illustrate alternative embodiments of the optical fiber isolator of FIG. 10 a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 a – 1 b illustrate the prior art arrangement based on a tapered fiber bundles for coupling light into cladding-pumped fibers. FIG. 1 a illustrates an arrangement ( 20 ) comprising a plurality of individual multimode fibers ( 21 ), which converge to a bundled region ( 22 ), which extends to a tapered region ( 23 ). The bundle tapers to a minimum diameter closely approximating the diameter of the cladding-pumped fiber ( 25 ). Finally, the tapered bundle is spliced to a cladding-pump fiber. Alternatively, the tapered bundle can be first spliced to an intermediate multimode fiber, which in its turn is spliced to a cladding-pumped fiber. Any of these arrangements can be referred to as bundling the plurality of optical fibers into a single composite fiber. It is contemplated that each individual multimode fiber ( 21 ) (of which only three are shown in FIG. 1 a ) will couple light from an associated semiconductor emitter source. FIG. 1 b shows an alternative arrangement ( 30 ) where one of the bundled tapered fibers is a single-mode fiber ( 24 ). The core of the single-mode fiber (dashed line) can be used to efficiently couple light through the taper into or out of the core of the cladding-pumped fiber while the multimode fibers ( 21 ) are used to couple light into the cladding of the cladding-pumped fiber. Such couplers are usually called M-plexers, or combiners, or tapered bundles.
FIGS. 2 a–b show alternative arrangements called side coupling. In FIG. 2 a, a feeding multimode fiber ( 21 ) is tapered ( 23 ), i.e. Heated and pulled, in order to reduce its diameter and then a coupler ( 40 ) is formed for example, by twisting and fusing such a tapered portion of the fiber ( 21 ) on the cladding-pumped fiber with preliminary removed polymer cladding. FIG. 2 b shows a side coupling ( 45 ) with a few multimode fibers ( 21 ).
Side coupling can be also provided through an optical contact between a feeding multimode fiber ( 21 ) and a cladding-pumped fiber ( 25 ). A fiber called GTwave™ (Southampton Photonics (SPI) of England) has been developed providing an optical contact between feeding fibers and a cladding-pumped fiber during a fiber drawing process. Such a contact along longitudinally extended fiber surfaces permits a distributed coupling of the pump light.
FIG. 3 a shows a prior art fiber laser embodiment comprising pigtailed semiconductor emitter sources ( 26 ) spliced to M-plexer ( 20 ), a fiber Bragg grating ( 32 ) written in piece of single-mode fiber recoated with low-index polymer and spliced with an output fiber of M-plexer from one side and with a cladding-pumped fiber ( 25 ) from the other side, and a fiber Bragg grating ( 33 ) written in a single-mode fiber ( 24 ) as an output coupler. The length of the fiber ( 25 ) is chosen to absorb, practically, all pump light (10 dB absorption). For example, a typical fiber length for Yb-doped fiber lasers varies from 7–10 m pumping at 976 nm to 20–30 m pumping at 915 nm. Although fluorescence spectrum extends from 1020 nm to 1150 nm most of such lasers generate in the region 1060–1100 nm. Generation at short wavelengths is inefficient because of strong re-absorption of the laser light in a long fiber cavity.
FIG. 3 b shows a prior art embodiment of the fiber laser. This embodiment comprises M-plexer ( 30 ) with a single-mode fiber in the center of the bundle. Such a scheme allow the high reflector ( 32 ) to be positioned outside of the active cavity providing better reliability for the fiber Bragg grating.
FIG. 4 shows a prior art fiber amplifier embodiment comprising pigtailed pump sources ( 26 ), two M-plexers ( 30 ) for pumping a fiber ( 25 ) from ends, a cladding-pumped fiber ( 25 ), and single-mode input and output fibers ( 24 ).
FIGS. 5–8 illustrate preferred arrangements of the invention. FIGS. 5 a,b illustrate the operation of a side de-coupler ( 50 ). A cladding pumped fiber ( 25 ), which may be designated an amplifier fiber, bearing a residual pump light is tapered in order to reduce its diameter ( FIG. 5 a ). A de-coupling multimode fiber ( 21 ), which may be referred to as a transmission fiber, is tapered ( FIG. 5 a ) and then fused to the tapered region of the fiber ( 25 ) to form a de-coupler ( FIG. 5 b ). It is preferable to have a diameter of the fiber ( 21 ) in the fused region larger than that of the tapered region of the fiber ( 25 ) because the amount of the residual pump power de-coupled from the fiber ( 25 ) to the fiber ( 21 ) is approximately proportional to the ratio between squares of the areas of the fiber ( 21 ) and the fiber ( 25 ). Alternatively, fibers ( 21 ) and ( 25 ) can be twisted before fusing. Alternatively, the tapered fibers ( 21 ) and ( 25 ) can be in optical contact with their surfaces with no fusion. Alternatively, the fibers ( 21 ) and ( 25 ) can be fused or can provide an optical contact in part of their length with no tapering. Alternatively, instead of the fiber ( 25 ) with a core doped by rare-earth ions a single-mode fiber with a non-doped core ( 24 ) can be used. In this case, the fiber ( 24 ) should be preliminary spliced to the cladding-pumped fiber ( 25 ).
FIG. 5 b shows de-coupling process. A signal light propagates in the core of the fiber ( 25 ) and a pump light propagates in a cladding of the same fiber. After the de-coupler the signal light propagates in a single-mode fiber ( 25 ) while the pump light propagate in multimode fibers ( 21 ). Small quantities of the residual pump light proportional to the ratio between the area of the single-mode fiber ( 25 ) and the total area of all multimode fibers ( 21 ) propagate in the fiber ( 25 ). Fibers ( 21 ) and ( 25 ) being in optical contact or fused can be recoated. The number of output ports of the de-coupler can be arbitrary. Advantageously, it should correspond to the number of free input ports in a ring cavity.
FIG. 5 c illustrates an arrangement ( 60 ) of a de-coupler based on a fused bundle comprising a plurality of individual multimode fibers ( 61 ), which converge to a bundled region ( 28 ), which extends to a tapered region ( 27 ). The bundle tapers to a minimum diameter closely approximating the diameter of an intermediate multimode fiber ( 29 ) and is spliced to that fiber ( 29 ). Alternatively, the tapered bundle can be spliced directly to the cladding-pumped fiber ( 25 ) or to a cladding-pumped fiber with a passive single-mode core (no doping with active ions generating light). FIG. 5 d shows an alternative arrangement ( 70 ) where one of the bundled tapered fibers from the arrangement ( 60 ) is a single-mode fiber ( 24 ). The core of the single-mode fiber (dashed line) can be used to transmit signal light through the taper out of the core of the cladding-pumped fiber ( 25 ) while the multimode fibers ( 61 ) are used to de-couple light from the cladding of the cladding-pumped fiber.
De-coupler based on tapered fiber bundle can be made as follows. A few multimode fibers with removed coating in the region where they will be bundled are bundled together into a close-packed formation. The central fiber within the bundle may be a fiber with a single-mode core. It is preferable to have this single-mode fiber pre-tapered or with a smaller cladding diameter compared to those of multimode fibers. The fibers are twisted under controlled tension. The bundle is then heated and pulled to provide adiabatical tapering to the final diameter of the cladding-pumped fiber.
The number of fibers, core diameters and numerical apertures depend on the cladding-pumped fiber parameters. There is a condition on fiber parameters for reducing losses in the de-coupler. In general, losses are minimized by maintaining the condition
S input ( NA input ) 2 ≤ ∑ S i , output ( NA output ) 2
where NA input , NA output are the numerical apertures of the cladding-pumped fiber and the output multimode fibers, respectively, S input is the area of the cladding-pumped fiber (or the minimum taper diameter), Σ S i,output is the summation of the cross areas of the fibers. This requirement is opposite to that applied to the prior art M-plexer ( 20 ). However, in practice, the pump light may not fill the whole numerical aperture of the cladding-pumped fiber. In this case, a de-coupler with the output fiber parameters not satisfying the above derived inequality may still provide low loss de-coupling of the residual pump power.
Typical multimode fibers shown in FIG. 5–7 have a silica core that is surrounded by a fluorinated cladding providing a numerical aperture from 0.12 to 0.22. Typical core diameters are 100–110 microns with outer cladding diameter of 125 microns. Fibers with 200/220 core/cladding diameters are also common. Multimode fibers with a silica core and a polymer cladding, holey (air-silica) multimode fibers can be also used.
FIG. 6 a shows a fiber arrangement ( 80 ) comprising a cladding-pumped fiber ( 25 ) with gradually reducing diameter along the length of the fiber, and a multimode fiber ( 81 ) with gradually increasing diameter along the length of the fiber. Fibers may be fused together or be in optical contact. A multimode fiber ( 81 ) is preferably a silica fiber with a polymer cladding or an all-silica fiber. Such a scheme with gradually changing parameters of the fibers provides an efficient de-coupling of the pump power at the end of the fiber ( 25 ) because the diameter of the fiber ( 81 ) at this end is larger than that of the fiber ( 25 ). In contrast, the diameter of the input end of the fiber ( 81 ) is less than that of the fiber ( 25 ) providing efficient coupling of the residual pump back to the cladding-pumped fiber ( 25 ). It is well known that reduction in the fiber core diameter increases the divergence angle of a beam propagating along the fiber. As long as such an angle remains smaller than the numerical aperture (NA) of the fiber, no excessive loss appears. As a result, coupling between such a tapered fiber and an un-tapered one can be very efficient. The arrangement ( 80 ) provides also a ring cavity for the residual pump increasing a pump power. density in the fiber ( 25 ). The arrangement ( 80 ) is not limited by fibers with gradually changing diameters. The cladding-pumped fiber ( 25 ) may have a constant diameter along its length, as shown in FIG. 6 b. Additionally, the fiber ( 81 ) may not form a continuous ring and may be of a constant diameter. The ends of the fiber ( 81 ) can be tapered and fused to the cladding-pumped fiber ( 25 ) as shown in FIG. 6 b. The taper from the pump input side can be done to provide efficient coupling of the residual pump power back to the fiber ( 25 ) using side coupling technique. The taper from the pump output side can be done using arrangement ( 50 ) for a side de-coupler. FIG. 6 b shows one of such arrangements ( 90 ).
FIG. 6 c illustrates a fiber arrangement ( 95 ) comprising a twisted cladding-pumped fiber ( 25 ), and a multimode fiber ( 81 ) with constant diameters along the fibers. Fibers may be fused together or be in optical contact. This arrangement is less efficient than that ( 80 ) and ( 90 ) in the sense of coupling back the residual pump power to the fiber ( 25 ); however, it is easier to fabricate. For example, the output ends of a GTwave™ fiber can be spliced back to open input ports providing a ring cavity for the residual pump. Additionally, more loops formed by fibers ( 81 ) can be attached to the cladding-pumped fiber ( 25 ) or to the other fibers ( 81 ) in arrangements ( 80 ), ( 90 ), ( 95 ).
Arrangements ( 80 ), ( 90 ), ( 95 ) are the simplest forms of a ring cavity for the pump light based on a side de-coupling by fusion or by optical contact through the side surfaces of fibers. The alternative way to form ring cavities for the pump light is to use de-couplers based on tapered fiber bundles ( 60 ), ( 70 ).
FIG. 7 a shows an arrangement ( 100 ) comprising an M-plexer ( 30 ), a de-coupler ( 60 ), a cladding-pumped fiber ( 25 ), a single-mode output fiber ( 24 ), and connecting multimode fibers ( 21 ). The number of the input ports of the M-plexer ( 30 ) is larger than the number of the output ports of the de-coupler ( 60 ). The output ports of the de-coupler ( 60 ) are spliced with the input ports of the M-plexer providing a ring cavity for the residual pump. The two open input ports ( 128 ) of the M-plexer can be used for pumping the cladding-pumped fiber ( 25 ). Note, the number of spliced and non-spliced fibers in the M-plexer is not critical and can vary depending on available pump power sources and parameters of the cladding-pumped fiber, M-plexer, and de-coupler. The fibers providing the pump light from the input ports 128 to the amplifier may be referred to as pump fibers while the fibers 21 which receive the unabsorbed portion of the pump light and return it to the fiber may be referred to as recovery fibers.
The advantage of the ring cavity can be understood from the following consideration. A pump power, P is launched through the input ports into the cladding-pumped fiber doped with ions having a three-level transition scheme. To avoid re-absorption in an amplifying fiber the length of this fiber should be short, resulting in non-efficient pump absorption. For the absorption of α=0.3, the residual pump power will be 70% of the initial one. Assuming that the de-coupler does not introduces any loss, the ring cavity will permit re-circulation of the residual pump power thereby increasing the pump power inside the cavity by a factor of approximately (1−α) −1 . An increase of the intracavity pump power favors to generation in three level systems. For example, generation at 976 nm in a cladding-pumped Yb-doped fiber pumped by multimode laser diodes at 915 nm with the cladding-pumped fiber diameter of 125 micron and NA of 0.45 requires a short cavity length with the pump absorption of 1–3 dB. The presented ring cavity for the pump light will provide an efficient use of all pump power.
FIG. 7 b shows a fiber laser arrangement ( 110 ) comprising a ring cavity ( 100 ), pump sources ( 26 ), and two fiber Bragg gratings ( 32 ), and ( 33 ). The fiber Bragg grating ( 33 ) can be also spliced directly to the fiber ( 25 ). All fiber Bragg gratings can be also replaced by dielectric mirrors.
The de-coupler may have different configurations. If the pumping light completely fills the numerical aperture of the cladding pumped fiber, it is preferable (although not critical) to have the same number of pump output ports in the de-coupler as the number of pump input ports in the coupler ( 20 ), ( 30 ), ( 40 ). The number of open input ports in the coupler may be less than that in de-coupler due to the number of input ports occupied by pump sources. In this case, the excess number of output ports can be used to send a residual pump back to the cavity as in a linear cavity case. As an example, in FIG. 7 c there are two mirrors ( 127 ) at the output of the fibers ( 129 ) to send a part of the residual pump back to the cavity. Instead of using mirrors, two output fibers ( 129 ) or more can be spliced to each other providing a loop ( 51 ) for the pump as is shown in FIG. 7 d. The fibers in the M-plexer and de-coupler forming a ring cavity for the pump preferably should have similar geometrical parameters to provide low loss splicing, although a small difference in numerical apertures and geometrical sizes is not critical. In this configuration, only a small part of a residual pump power is reflected back. This power is proportional to the ratio between ports occupied by pump sources ( 26 ) and open ports in the input M-plexer ( 30 ). Most of the residual pump power circulates through the spliced output and input fibers ( 21 ).
If a reflected back pump power is strong enough to damage the pump laser, it is preferable to use a de-coupler with the number of ports equal or less than a number of open ports in the M-plexer, as shown in FIG. 7 b.
In some cases, a pump source ( 26 ) does not fill the entire numerical aperture of an input fiber ( 21 ) in M-plexers and couplers ( 20 ), ( 30 ), ( 40 ), or most of the energy is concentrated in an angle range less than a numerical aperture of the fiber ( 21 ). For example, the fiber ( 21 ) may have a typical numerical aperture of 0.22, however, 90% of the pump source ( 26 ) energy is concentrated in a cone corresponding to the numerical aperture of 0.15. In this case, the number of output ports in the de-coupler may be less than the number of the input ports of the M-plexers and side-couplers. Such a de-coupler may still provide a low-loss de-coupling of the pump power.
FIG. 7 e shows an optical amplifier ( 140 ) arrangement comprising a ring pump cavity arrangement with the pump power partially reflected back by mirrors ( 27 ), and pump sources ( 26 ).
A ring cavity for the residual pump light can be also used with bulk optics. FIG. 8 shows a fiber laser arrangement comprising a ring pump cavity arrangement with lenses ( 37 ), bulk mirrors ( 38 ) butted to a cladding-pumped fiber ( 25 ), pump sources ( 26 ), a dichroic mirror ( 39 ) that is transparent for a pump light and is reflective for a laser light, M-plexer ( 20 ), connecting fibers ( 21 ), and de-coupler ( 60 ). Similar arrangements can be provided for crystal lasers and waveguide lasers.
Fiber lasers based on ring cavity arrangements for a residual pump can be efficient sources of powerful radiation in three-level systems. In turn, radiation from these lasers can be used to pump the other lasers. For example, light from a Nd-doped fiber laser at 910–940 nm, as well as light from an Yb-doped fiber laser at 976 nm and at 1020–1040 nm can be used to pump the next Yb-doped fiber laser or amplifier to get generation at 1020–1150 nm. The output light from each of the pump fiber lasers has a good beam quality, low NA, and a small cross-section, corresponding to a single-mode or a few modes, or a large mode area fiber. Because brightness of these pump fibers is much higher than that of multimode laser diodes or laser bars the second cascade fiber laser or amplifier may have a reduced cladding diameter and/or reduced numerical aperture compared to those of the pumping fiber lasers. By this arrangement, an all-silica (or in general an all-glass) cladding structure can be constructed for the second fiber laser cascade. It is important for high power fiber lasers to have a cladding not from a low-index polymer, but from silica. A silica cladding can withstand a higher pump power level compared to a polymer cladding.
FIG. 9 shows a high power fiber amplifier arrangement comprising many individual pump fiber lasers, M-plexer ( 30 ), a cladding-pumped fiber ( 25 ), and single-mode input and output fibers ( 24 ). Pump fiber lasers may use a ring pump cavity design, for example, arrangement ( 100 )—as shown in FIG. 7 b. The pump light from N individual fiber lasers is combined in a tapered bundle ( 30 ) and enters into the cladding of the fiber ( 25 ). A signal light enters through a single-mode fiber ( 24 ) into the cladding-pumped fiber ( 25 ), is amplified, and goes out through the other single-mode fiber ( 24 ).
An inventive arrangement of an all-fiber high power master oscillator—power amplifier scheme with no bulk isolators is next described. In one aspect, the arrangement comprises a fiber laser operating in CW, or Q-switched, or mode-locked regime and generating a signal at a wavelength shorter than that will be amplified, a fiber isolator arrangement, and a fiber amplifier providing amplification of the Stokes signal. The inventive arrangement uses stimulated Raman scattering to shift the frequency of a signal (pump signal) from a master oscillator (or a first amplifier) to longer wavelengths in the Stokes region (Stokes signal) along with one or more spectrally selective fiber optic elements (fiber isolators) suppressing penetration of the Stokes signal back to the master oscillator, and suppressing penetration of the pump signal in the power amplifier. The arrangement comprises a length of a fiber to generate the Stokes signal. A fiber isolators may include one or more of a wavelength-division multiplexer (WDM), a slanted, blazed, or long-period fiber gratings, single-mode fiber to multimode fiber couplers, and a piece of a fiber doped with ions absorbing either the pump signal or the Stokes signal.
FIG. 10 a shows an embodiment of the inventive arrangement including a fiber master oscillator ( 210 )—power amplifier ( 220 ) system with all-fiber isolator arrangement. Traditionally, a bulk isolator is placed between a master oscillator and a power amplifier to prevent interaction between them. Fiber amplifiers usually exhibit strong gain (>20 dB), thus a strong isolation is required to prevent any reflection back to a power amplifier. Strong amplified spontaneous emission from a power amplifier may also disturb generation in a master oscillator. For a multi-cascade amplifier the isolation requirements between cascades are even stricter. The risk of optical damage limits using bulk optics in the case of single-mode fibers amplifiers. There is a strong need in an all-fiber isolator which would prevent a feedback between a master oscillator and a power amplifier or between two amplifiers.
The isolator operates as follows. Light at wavelength λs comes out of the master oscillator ( 210 ). In general, an arbitrary fiber amplifier cascade can be considered instead of the master oscillator ( 210 ) in FIG. 10 a. It is preferable that λs is not in the band of amplification of the power amplifier ( 220 ) or is in a short wavelength side of that band. A spectrally selective element ( 201 ) including a WDM ( 212 ) transmits light at wavelength λs, and switches light corresponding to the first Stokes shift λ St from one arm to another one. In a piece of a fiber ( 211 ) the signal light generates a Stokes signal at wavelength λ St by stimulated Raman scattering. The fiber length is chosen to provide an efficient conversion of the input light to the Stokes component. The next element ( 202 ) is a WDM ( 213 ) to separate a Stokes signal at λ St and a residual input signal at λs by switching the Stokes signal in the other arm of a WDM ( 213 ). This element prevents penetration of a residual input signal into a power amplifier ( 220 ). This Stokes signal is amplified in a power amplifier ( 220 ). The Stokes signal wavelength is chosen preferably (but not necessarily) in the maximum gain region.
An amplified spontaneous emission (ASE) from a power amplifier ( 220 ) propagates back towards a master oscillator ( 210 ) through blocks ( 202 ), ( 201 ), and a fiber ( 211 ). To prevent a feedback between a master oscillator ( 210 ) and an amplifier ( 220 ) ASE should be efficiently suppressed. To provide a sufficient extinction for ASE a few WDMs ( 201 ) can be used with similar or slightly shifted central wavelengths. As an alternative to a WDM, an element ( 203 ) including slanted or blazed fiber Bragg gratings ( 214 ) can be used. Such a blazed fiber Bragg grating will de-couple ASE from the fiber core to a cladding in backward direction ( FIG. 10 b ). An alternative solution for element ( 201 ) is an element ( 204 ) with a long-period fiber grating ( 215 ) that de-couples ASE from a fiber core to a cladding in forward direction ( FIG. 10 c ). FIG. 10 d shows another alternative solution ( 205 ) for an element ( 201 ) comprising a piece of a fiber ( 216 ) doped with ions absorbing ASE. For example, Sm-doped fibers exhibit strong absorption at 1060–1090 nm and, practically, are transparent at 975–1050 nm. Thus, a master oscillator can be chosen to generate light at 1020–1050 nm while a Stokes shifted signal and ASE corresponding to maximum amplification at 1070–1090 nm in Yb-doped fiber amplifier exhibit strong absorption in Sm-doped fiber. Spectrally selective elements ( 201 )–( 205 ) can be also chosen to provide transmission for a Stokes signal and to provide extinction for an input signal. In this case, these elements should be preferably placed after WDM ( 202 ).
Another alternative solution is an element ( 206 ) presented in FIG. 10 e comprising a splice between a fiber with a small core area ( 217 ) and a fiber with much larger core area ( 218 ). Light propagating from a small core area fiber towards a large core area fiber will exhibit less attenuation than counter-propagating light. A short piece of a large core area fiber ( 218 ) will not disturb a mode distribution of a small core area fiber ( 217 ). An adiabatic taper ( 219 ) will couple light back to a small core area fiber ( 221 ) with low loss (<1 dB). Counter-propagating light from a fiber ( 221 ) to a fiber ( 217 ) will exhibit strong loss at the splice between a fiber ( 217 ) and a fiber ( 218 ). This loss is approximately proportional to the ratio between core areas of two fibers. For example, difference in core diameters of 3.1 times results in attenuation of 10 dB for a counter-propagating signal. Element ( 206 ), practically, is not spectrally selective and can be used with or even without elements ( 201 )–( 205 ) and a fiber ( 211 ). A few elements ( 206 ) can provide a good isolation from ASE. Elements ( 201 )–( 206 ) can be used in a series in any combination with each other.
Although the above-derived embodiments consider optical fiber arrangements, the invention can be applied to any waveguide lasers and amplifiers and is not limited by fiber arrangements only.
While the above invention has been described with particularity to specific embodiments and examples thereof, it is understood that the invention comprises the general novel concepts disclosed by the disclosure provided herein, as well as those specific embodiments and examples, and should not be considered as limited by the specific embodiments and examples disclosed and described herein. | Apparatus for optically pumping a clad amplifier fiber includes one or more transmission fibers arranged and configured to insert pump-light from a pump light source such as a diode-laser into the cladding of the amplifier fiber. The pump light propagates through the cladding and a portion of the pump light is absorbed in the doped core of the amplifier fiber. At least one of the transmission fibers is arranged to receive an unabsorbed portion of the propagated pump light from the amplifier cladding and re-insert the unabsorbed portion of the pump-light into the cladding for re-propagation through the cladding. This provides that pump light that would otherwise be wasted is circulated through the amplifier fiber for further absorption by the amplifier core. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. patent application Ser. No. 11/117,990 filed Apr. 29, 2005, now U.S. Pat. No. 7,347,459, which claims the benefit of U.S. Provisional Application No. 60/567,031 filed Apr. 30, 2004, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to threaded API casing connections, but more specifically to the couplings for API Buttress threaded casing to be used as a combination drill string and casing string—i.e., Drilling With Casing (DWC).
2. Description of the Related Art
Presently the conventional method for drilling oil and gas wells is to use drill pipe specifically designed for and dedicated to drilling the well bore. Upon drilling a well to completion, the drill pipe is pulled from the well and transferred to the next location for drilling another well. The drill pipe is thus used until it is worn out. The open hole left by the drill pipe is sealed off by running a string of casing pipes to the bottom of the hole and cementing the casing string in place.
In contrast to the above procedure, it is the purpose of new technology to eliminate the use of the above-described drill pipe and instead use the casing string for both drilling the well and casing off the open hole. The procedure is commonly referred to as “Drilling With Casing” (DWC). This procedure has been tried in various parts of the world but with limited success. However DWC offers so much potential for reducing drilling costs that interest remains high throughout the industry and many new projects are aimed at advancing the technology.
In conventional casing usage, the casing and its connections are subjected only to static loads comprising tension, torsion, compression, bending, pressure and any combination thereof. In DWC usage, the casing and connections are not only subject to all of the above static loads, but also to dynamic loads due to rotating the casing at 100 to 150 RPM while drilling the well bore. As the casing rotates and advances down the well bore, the casing string and particularly the connections, which have a larger outside diameter than the casing, are subject to cyclic fatigue loads, severe abrasion wear and impact loading, then finally to all the static loads mentioned above after the casing is set and cemented in the well.
This invention is directed at one of the primary problems associated with DWC—the connections which join each length of casing, one to another. Experience to date with DWC has demonstrated a need for a more robust, yet economical casing connection to withstand the additional rigors of dynamic loading and frictional wear caused by rotating the string while drilling.
BRIEF SUMMARY OF THE INVENTION
The invention comprises the following modifications of the standard API Buttress threaded coupling only, while maintaining it's compatibility with standard API Buttress threaded Pins:
1. The coupling threads only are modified with multiple tapers to reduce and equalize makeup stresses through the thinner cross-sections of both the pins and coupling, thereby minimizing the possibilities of thread galling during connection assembly. 2. The multiple thread taper reduces the bearing stresses, and therefore the localized stress risers in the run-out pin threads where the connections commonly fail in fatigue, under rotational cyclic loading. 3. The coupling is shortened to allow abutment of the two pins at the center of the coupling maximizing the torque capabilities of the connection. 4. The coupling can be formed with an integral, sacrificial wear-sleeve extension, protecting the coupling proper from frictional wear as the casing is rotated down the well bore.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a side view, partially in cross-section, of two pipes joined with a coupling of the prior art.
FIG. 2 is a side view, partially in cross-section, of two pipes joined with a prior art coupling having a center section of increased thickness.
FIG. 3 is a side view, partially in cross-section, of two pipes joined with a coupling according to the present invention.
FIG. 4 is a side view, partially in cross-section, of two pipes joined using an alternative embodiment of the present invention. FIG. 4A is an enlarged view of the leading edge portion of the wear sleeve.
FIG. 5 is a side view, partially in cross-section, of two pipes joined using a third embodiment of the present invention.
FIG. 6 is a side view, partially in cross-section, of two pipes joined using a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Casing Couplings of the Prior Art
Referring now to the drawing in FIG. 1 , a standard API Buttress Threaded casing string 10 and coupling 15 according to the prior art is illustrated. The casing string 10 includes two casing sections, or pipes, 11 and 12 , having pin ends 11 A and 12 A, interconnected with a coupling 15 according to the prior art. FIG. 1 shows the connection fully assembled. Note the separation between pin ends 11 A and 12 A. This gap between the pins is commonly known as the “J” area.
Still referring to FIG. 1 , the casing members 11 and 12 include pin threads 13 and 14 on the outside end of each casing section, the threads mating with the threaded internal surface of the coupling 15 . The coupling 15 includes a first end 18 and a second end 19 with internal threaded surfaces 16 and 17 . The threads are preferably tapered API Buttress threads as are commonly used in the industry and in this application. However, other thread forms may be used.
Now referring to FIG. 2 , which shows another oil well casing connection in accordance with U.S. Pat. No. 5,015,017, a casing string is illustrated generally at 20 . The casing string 20 includes two casing sections 21 and 22 interconnected with coupling 25 , and the casing sections include external API Buttress pin threads 23 and 24 which mate with matching coupling threads 26 and 27 .
Essentially FIG. 2 is the same as FIG. 1 with the exception that the “J” area between pin ends 23 & 24 contains an integral reinforcing cross-section 30 of the coupling 25 . This heavy cross-section 30 substantially improves the strength of the coupling by converting the structural/mechanical behavior of the coupling from a simple beam to a cantilever beam. The visual contrast is readily noted by comparing the cross-sections of coupling 15 ( FIG. 1 ) and coupling 25 ( FIG. 2 ). Both connections preferably use the Standard API Buttress threads and are interchangeable with each other.
Casing Couplings According to the Present Invention
With reference to FIG. 3 and this invention, a casing string is illustrated with two casing sections 41 and 42 interconnected with coupling 45 and the casing sections include externally threaded pins 43 and 44 , which mate with internal coupling threads 60 . Threaded pins 43 and 44 contain standard API Buttress Threads with a constant taper. The faces of the two pin ends 65 are square cut to furnish maximum bearing face when butted together at center 50 of coupling 45 .
Again referring to FIG. 3 and this invention, it is standard with the API Buttress Thread Form for the coupling threads 60 and pin threads 43 , 44 to have identical thread tapers so as to produce uniform radial thread interference through the full length of the thread profile. When the connection is assembled, it is this thread interference that creates the contact pressure and therefore the sealing capabilities of the mating threads.
It will be further noted in FIG. 3 that the thread tapers of the pin and coupling members result in variable cross-sections along the thread profile of each member, with a thinner cross-section at pin ends 65 and similar thinning cross-sections at coupling ends 53 . When the connection is assembled it is seen that the thinner cross-sections of the respective pin and coupling members are opposite the heavier cross-sections of the mating member. The cross-sections therefore are unbalanced at the thinner ends of both members. When the connection is assembled, it is this imbalance between these cross-sections and the resulting excessive hoop stresses in the thinner cross-sections, that this invention addresses.
Referring again to FIG. 3 , it is evident that a uniform taper between the pin and coupling threads results in uniform interference along the thread profile. However, as pointed out above, the cross-sections of the mating members vary along the thread profile. Therefore, if the interference between the threads is uniform, but the cross-sections behind the threads are variable, then the resulting hoop stresses created in the cross-sections must also be variable; graduating from low stresses in the thicker part of the cross-section to high stresses in the thinner part. Indeed it has been found through Finite Element Analysis (FEA) that, after assembly, the hoop stresses in the thinner cross-sections of both the pins and coupling can exceed the yield strength of the steel. In addition to the negative impact on the yield strength, in the thinner portions of the mating members this differential yielding at the thin vs. thick cross-sections also causes differential movement between the threads at these same high stress points. This differential movement, at the high stress points, in turn results in thread galling in both coupling and pins at 65 and 66 . It is also anticipated that these same high stressed areas, particularly at the run-out threads 66 of the pin members 43 and 44 , could result in fatigue failure when the connections are used in the drilling mode (DWC).
Referring again to FIG. 3 . there is shown a cross-sectional view of a shortened API Buttress Threaded coupling 45 connecting two Buttress Threaded Pins 43 and 44 that abut at the center of the coupling 45 . FIG. 3 illustrates this shortened and multiple tapered coupling designed to:
1) Moderate the concentrated high stresses previously outlined
2) Minimize the thread galling in the areas of high stress
3) Maintain compatibility with standard API Buttress threaded pin members
4) Create a high torque connection by butting the pin ends at the center of the coupling
To accomplish these objectives the thread tapers in only the coupling member 45 are modified at the areas of high stress; i.e., the areas of cross-sectional imbalances at coupling ends 53 and pin ends 65 . As shown in FIG. 3 the thread taper in coupling 45 is segmented into sections S 1 , S 2 and S 3 . In the present invention the taper in section S 2 is maintained at the API standard taper. The taper in section S 1 is greater than the taper in section S 2 , and the taper in section S 2 is greater than the taper in section S 3 . The variable tapers in coupling 45 relative to the uniform tapers of pins 43 and 44 reduce bearing pressures in the mating thread elements in areas of the connection with unbalanced cross-sections; i.e. 65 on the pin ends and 53 of the coupling ends. The employment of multiple tapers reduces the contact pressure in the overstressed areas S 1 and S 3 and thus mitigates the problems of high stresses, thread galling and fatigue failure.
In one preferred embodiment, the threaded section on each side of a 7-inch API Buttress coupling is divided into three sections as previously described. The lengths and tapers for each section in this preferred embodiment are:
Section
Length (in)
Taper (in./in.)
1
1.784
0.07525
2
1.716
0.06250
3
1.125
0.05556
The section lengths and tapers employed in this invention are designed to reduce contact pressure in areas of the connection where cross-sections are unbalanced.
It might be noted that other taper profiles, such as elliptical or curved, might be used, but the segmented profile is preferred because it maximizes the length of section S 2 which has the same taper on both members therefore maximizing sealing integrity. It is emphasized that only the coupling tapers need be modified.
It is also emphasized that the pin threads 43 and 44 should be made to standard API Buttress specifications with no modifications to length or taper. This allows the casing pipes to be threaded by the many API licensed machine shops or mills in the world. By contrast there are only a few coupling manufacturers in the world and most have the modern equipment to machine the modifications required by this invention. Also couplings are easily transportable as opposed to 40′ lengths of pipe.
Again in FIG. 3 , the coupling is shortened by approximately ¾ inch, removing what is commonly known as the “J” area between the two pin members as previously pointed out in FIG. 1 . In this invention, elimination of the “J” area allows the two pins to butt one another at the coupling center thereby maximizing the torque capabilities of the connection and its use for DWC.
Now referring to FIG. 4 , an optional unthreaded extension 70 can be integrally machined on one end of the coupling 55 . The purpose of the extension is to provide a sacrificial wear sleeve to protect the main body of the coupling as the casing is rotated down the well bore. The wear sleeve would have the same outside diameter as the coupling with the inside diameter being slightly larger than the casing so as to slip over the casing when the connection is assembled. As an option, the wear sleeve can be hard banded if excessive abrasion is anticipated.
Again at FIG. 4 the inside diameter of the wear sleeve is uniform from the face 72 for a specific distance toward the center of the coupling, then is tapered outward toward the coupling OD 73 . This design detail is provided to permit the threading tool to cut perfect (full-formed) threads over the entire coupling thread length without cutting into the ID of the sacrificial wear sleeve. Elimination of machining marks in the wear sleeve near the coupling threads reduces the possibility of fatigue failures in the sacrificial wear sleeve extension.
In an alternative embodiment illustrated in FIGS. 5 and 6 , an API Buttress coupling has an internal reinforcing cross-section 80 at the center or in the “J” area. In this embodiment, each pin engages an internal square shoulder 82 at the heavy cross-section thereby maximizing the torque capability of the connection for its use for DWC.
As in the embodiment shown in FIG. 4 , an optional unthreaded extension 70 can be integrally machined on one end of the coupling 55 . This feature is illustrated in FIG. 6 . The purpose of the extension 70 is to provide a sacrificial wear sleeve to protect the main body of the coupling as the casing is rotated down the well bore. The wear sleeve would have the same outside diameter as the coupling with the inside diameter being slightly larger than the casing so as to slip over the casing when the connection is assembled. As an option, the wear sleeve can be hard banded in area 74 if excessive abrasion is anticipated.
Again, as in the embodiment shown in FIG. 4 , the inside diameter of the wear sleeve is uniform from the face 72 for a specific distance toward the center of the coupling, then is tapered outward toward the coupling OD 73 . This design detail is provided to permit the threading tool to cut perfect (full-formed) threads over the entire coupling thread length without cutting into the ID of the sacrificial wear sleeve. Elimination of machining marks in the wear sleeve near the coupling threads reduces the possibility of fatigue failures in the sacrificial wear sleeve extension.
It should be noted and anticipated that certain changes may be made in the present invention without departing from the overall concept described here and it is intended that all matter contained in the foregoing shall be interpreted as illustrative rather than in a limiting sense. | A threaded casing connection for use in drilling-with-casing operations includes an integral, sacrificial wear sleeve on the downhole end of the coupling which has additional wear protection on portions of its outer wall and leading face. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to latching mechanisms, and more particularly, to a spring biased latching arrangement having a latch pivotable about an axis for use with a refrigerator door.
BACKGROUND OF THE INVENTION
[0002] Refrigerators for use in recreational vehicles require a positive latching to keep the doors closed when the vehicle is in motion. Commonly, many such refrigerators have a handle on the top or front of the door that requires the user to first slide a catch and then pull the handle to open the door, or to rotate or otherwise manipulate the handle to open the door, in a manner which is different from the opening of a door of a home refrigerator which need not be positively latched. Thus, users often perceive a difference between a refrigerator for a recreational vehicle as compared to a residential refrigerator due to the extra steps or different motion required for door opening. An effort has been made in the pertinent art to make refrigerators and other conveniences for recreational vehicles as “home-like” as possible. Accordingly, a need exists for a latching mechanism for a refrigerator for use in a vehicle which provides users with a positive latching arrangement that is substantially transparent to the user and thereby more similar to a home refrigerator.
SUMMARY OF THE INVENTION
[0003] In one form, the present invention provides latching arrangement for a refrigerator. The refrigerator includes a housing, a door pivotally coupled to the housing, and a striker connected to the housing. The latching arrangement is carried by the door. The latching arrangement includes a handle and a pawl. The handle is connected to the door for movement between a first position and a second position. The handle defines at least one cam surface. The pawl is connected to the door for movement between a latched position and an unlatched position. In the latched position, the pawl is engaged with the striker for securing the door in a closed position. In the unlatched position the pawl allows the door to be pivoted from the closed position. The pawl includes a cam follower that cooperates with at least one cam surface such that movement of the handle from the first position to the second position moves the pawl from the latched position to the unlatched position.
[0004] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0006] FIG. 1 is a perspective view of a refrigerator incorporating a latching arrangement constructed in accordance with the teachings of the present invention;
[0007] FIG. 2 is an enlarged perspective view of a portion of the refrigerator of FIG. 1 ;
[0008] FIG. 3 is an exploded perspective view of the spring biased latching arrangement of the present invention and an associated mounting portion of the refrigerator;
[0009] FIG. 4 is a cross-sectional plan view along section line 4 - 4 of FIG. 2 showing the latching arrangement in a latched position; and
[0010] FIG. 5 is a cross-sectional view of the spring biased latching arrangement shown in FIG. 2 in an unlatched position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0012] The present invention is generally related to a latching arrangement for use in a recreational vehicle or other vehicle (e.g., train, boat, airplane or the like) in which positive latching is required during vehicle operation. In this regard, the latching arrangement will be described in the context of a refrigerator for use in a recreational vehicle. In the exemplary embodiment illustrated throughout the drawings, the refrigerator is of the type having a top freezer and a bottom refrigerator section, but the present invention is equally applicable to any other type of refrigerator configuration. Furthermore, it is to be understood that the principles embodied herein are equally applicable to other types of appliances in general and to other types of appliances used in motor vehicles as well.
[0013] Referring first to FIGS. 1 and 2 , a refrigerator 10 for use in a recreational vehicle is shown. The refrigerator 10 is shown to generally include a housing 12 . In one embodiment, the refrigerator 10 defines a freezer section or compartment 14 and a refrigerator section or compartment 16 . The freezer section 14 is shown positioned above the refrigerator section 16 . The refrigerator 10 may further include a control panel 18 situated between the freezer section 14 and refrigerator section 16 . In a known manner, the control panel 18 provides temperature controls for the freezer 14 and refrigerator section 16 . The freezer section 14 and refrigerator section 16 are accessible through upper and lower doors 20 and 22 , respectively. The doors 20 , 22 are conventionally mounted to the housing 12 for rotation about a vertically extending pivot axis X between closed positions (shown in FIG. 1 , for example) and open positions (not specifically shown).
[0014] A latching arrangement 24 in accordance with an embodiment of the present invention is carried by each of the doors 20 and 22 . As will become more apparent below, the latching arrangement 24 permits the associated door 20 or 22 to be positively latched, as well as easily opened to allow access to the storage compartment. As used herein, the term “positively latched” will be understood to refer to a secured condition in which movement of an element is required prior to opening of the door 22 .
[0015] In one embodiment, the latching arrangement 24 may be disposed at the bottom of the door 20 of the freezer section 14 and at the top of the door 22 of the refrigerator section 16 so as to place them adjacent to each other. The remainder of this detailed description will focus on the latching arrangement 24 for the lower door 22 . It will be understood that the upper door 20 may employ a substantially identical latching arrangement. The only difference between the implementation of the latching arrangement 24 for the refrigerator section 16 and the freezer 14 being the orientation of an accommodating recess 26 . Thus, the latching arrangement 24 for the door 20 of the freezer 14 has not been shown.
[0016] With continued reference to FIGS. 1 and 2 and additional reference to FIGS. 3 through 5 , the latching arrangement 24 of the present invention will be described in greater detail. The door includes a side defining a recess 26 . In the embodiment illustrated, the door 22 is shown to include a cap portion 23 . The cap portion 23 defines the recess or opening 26 . The latching arrangement 24 is substantially disposed within this recess 26 of the door 22 . As will become apparent, location of the latching arrangement 24 within the recess 26 makes the latching arrangement 24 substantially hidden when the door 22 is closed. It will be appreciated by those skilled in the art that the recess may be alternatively provided in the bottom side or a lateral side of the door 22 .
[0017] The latching arrangement 24 generally includes a door handle 28 , a door pawl 30 and an end cap or housing 32 . In one particular application, the door handle 28 is made from a rigid plastic. However, the door handle 28 may be constructed of any material having suitable strength and durability characteristics. The door handle 28 includes an opening 34 at a first end 36 for receipt of a handle shoulder screw 38 therethrough. The handle shoulder screw 38 pivotally couples the first end 36 of the door handle 28 to a mounting location within the recess 26 in the door 22 . Although a shoulder screw is used in the illustrated embodiment, it will be understood that other fastening mechanisms may be used to rotatably couple the door handle 28 to the recess 26 in the door 22 . In this regard, a pin or other structure may be alternatively used for pivotal coupling.
[0018] The door handle 28 is coupled to the door 22 for rotation about the screw 38 . Explaining further, the screw 38 defines an axis V 1 about which the door handle 28 is movable between a first position and a second position. The first position is shown in FIG. 4 . The second position is shown in FIG. 5 . In the embodiment illustrated, the axis defined by the screw 38 is generally vertical. On a lateral side application, the axis of the screw is vertical.
[0019] The door handle 28 also includes a biasing member 40 . The biasing member may be in the form of a leaf spring 40 located proximate a second end 42 of the handle 28 . The leaf spring 40 is carried by the door handle 28 in a predetermined location. In one application, the leaf spring 40 is integrally formed with the remainder of the door handle 28 . The leaf spring 40 may also be formed as a discrete part from plastic or metal and attached to the door handle 28 in any manner well known in the art. Suitable methods of attachment include, but are not limited to, welding and adhesive bonding. The biasing member 40 biases the handle 28 about the screw 38 to the first position.
[0020] The door handle further includes two pairs of slotted fingers 44 located adjacent to the leaf spring 40 proximate the second end 42 of the door handle 28 . The pairs of slotted fingers 44 are spaced apart at the second end 42 of the handle 28 by a distance substantially equal to the thickness of the door pawl 30 . The pairs of slotted fingers 44 cooperate to define a parallel curved or arcuate slot 46 therebetween which engages a portion of the door pawl 30 . Explaining further, the inner surfaces of the slot 46 define cam surfaces for cooperating with the pawl 30 . The curved slots 46 each have a first end 48 which curves down to a second end 50 as best shown in FIG. 4 . The first ends 48 of the curved slots 46 are in engagement with the door pawl 30 when the door 22 is closed. When the door handle 28 is engaged, the second ends 50 of the curved slots 46 engage the door pawl 30 to unlatch the door 22 .
[0021] With particular reference to FIG. 3 , the door pawl 30 has a cylindrical post or cam follower 52 formed with a main body 54 . The cylindrical post 52 of the door pawl 30 slides between the first ends 48 and second ends 50 of the curved slots 46 in the pairs of slotted fingers 44 of the door handle 28 . Engagement of the cylindrical post 52 with the curved slots 46 of the door handle 28 permits the door pawl 30 to rotate only when the door handle 28 is rotated, as will be discussed later.
[0022] The main body 54 of the door pawl 30 further includes a first boss 56 , a second boss 58 and a hook 60 . The first boss 56 and second boss 58 define an opening 62 through the main body 54 for receipt of a pawl shoulder screw 64 therethrough. The pawl shoulder screw 64 pivotally couples the door pawl 30 to the door 22 for movement about a vertical axis V 2 (shown in FIGS. 4 and 5 ). The pawl 30 is movable from a latched position. Although a shoulder screw is used in this embodiment, it will again be understood that other fastening mechanisms may be used to rotatably couple the door pawl 30 to the recess 26 in the door 22 , such as, for example, a pin.
[0023] The hook 60 engages a fixed cabinet receiver or striker 66 to secure the door 22 to the cabinet 12 in the closed position as shown in FIG. 4 . Due to the cooperating shape and orientation of both the hook 60 of the door pawl 30 and the cabinet receiver 66 , centrifugal force applied to the door 22 that frequently results during vehicle transit, urges the hook 60 against the cabinet receiver 66 . This relationship prevents the door 22 from unintentionally opening during transit. As particularly shown in FIG. 5 , when the door handle 28 is engaged, the hook 60 is disengaged from the cabinet receiver 66 , and the door 22 is free to be opened. Thus, the mating surface between the hook 60 and cabinet receiver 66 is configured such that the hook 60 can rotatably disengage from the cabinet receiver 66 upon rotation of the door handle 28 . The hook 60 of the door pawl 30 further extends through the end housing 32 as best shown in FIGS. 2 and 3 .
[0024] The end housing 32 has an opening 68 through which the hook 60 of the door pawl 30 extends. The end housing 32 has a first slot 70 and a second slot 72 which both snap fit to a side edge 74 of the recess 26 to secure the end housing 32 to the recess 26 . The end housing 32 conceals the remainder of the latching arrangement 24 when the door 22 is open.
[0025] When the door 22 is closed, as shown in FIG. 4 , the cabinet receiver 66 is engaged with the hook 60 of the door pawl 30 . The door handle 28 is displaced from a front edge 76 of the recess 26 by the leaf spring 40 such that the pairs of slotted fingers 44 abut a stop 78 located at a back edge of the recess 26 . The leaf spring 40 keeps the door handle 28 urged against the stop 78 , which in turn applies a constant force on the door handle 28 that prevents the door handle 28 from moving and vibrating during the operation of the vehicle. This constant force also ensures that the hook 60 stays engaged with the cabinet receiver 66 . In addition, the pairs of slotted fingers 44 of the door handle 28 are positively engaged with the door pawl 30 . More specifically, the cylindrical post 52 of the door pawl 30 is disposed in the first ends 48 of the curved slots 46 formed in the pairs of slotted fingers 44 .
[0026] With particular reference to FIG. 5 , the door 22 is opened by depressing the door handle 28 to overcome the biasing force of the leaf spring 40 . In particular, a force F must be applied to the door handle 28 sufficient enough to cause the door handle 28 to rotate about the vertical axis V 1 , defined by the handle shoulder screw 38 , such that the door handle 28 is moved into a position adjacent to the front edge 76 of the recess 26 . As the force F is applied to the door handle 28 , the leaf spring 40 is depressed and the cylindrical post 52 of the door pawl 30 slides from the first ends 48 of the curved slots 46 in the pairs of slotted fingers 44 to the second ends 50 . The motion of the cylindrical post 52 through the curved slots 46 causes the door pawl 30 to rotate about the vertical axis V 2 defined by the pawl shoulder screw 64 , and subsequently causes the main body 54 of the door pawl 30 to partially pass through the pairs of slotted fingers 44 . In this manner, movement of the handle 28 from the first position to the second position functions to move the pawl 30 from the latched position to the unlatched position. The rotation of the door pawl 30 disengages the hook 60 from the cabinet receiver 66 , releasing the door 22 . When the door handle 28 is adjacent to the front edge 76 of the recess 26 , the hook 60 is adjacent to the stop 78 on the back edge 80 of the recess 26 .
[0027] Thus, for a user to open the door 22 , the fingers of a hand are inserted into the recess 26 and the door handle 28 is pulled towards him/her against the force of the leaf spring 40 . Once the door 22 is open, the user can cease to compress the door handle 28 , and the integral leaf spring 40 will force the door handle 28 away from the front edge 76 of the recess 26 , and allow the hook 60 of the door pawl 30 to re-engage the cabinet receiver 66 when the door 22 is closed. The concealed door handle 28 provides a smoother, aesthetically pleasing look to the doors 20 , 22 and permits the space between the freezer 14 and refrigerator section 16 to be narrower. This in turn increases the capacity of the freezer 14 and refrigerator section 16 . The narrow space also enables a smaller and sleeker control panel 18 to be implemented.
[0028] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | A latching arrangement for a refrigerator positively latches a door of the refrigerator. The refrigerator includes a housing. The door pivotally coupled to the housing. A striker is connected to the housing. The latching arrangement is carried by the door. The latching arrangement includes a handle and a pawl. The handle is connected to the door for movement between a first position and a second position. The handle defining at least one cam surface. The pawls is connected to the door for movement between a latched position engaged with the striker for securing the door in a closed position and an unlatched position allowing the door to be pivoted from the closed position. The pawl includes a cam follower that cooperates with the at least one cam surface such that movement of the handle from the first position to the second position moves the pawl from the latched position to the unlatched position. The latch is partly or completely concealed in the door edge. | 5 |
BACKGROUND OF THE INVENTION
The invention is directed to new benzhydrol derivatives which are distinguished by fungicidal activity, especially against Piricularia oryzae in rice, a process for the production of these compounds, agents containing these compounds as active material, as well as the use of these active materials as a fungicidal agent in the protection of plants.
It is known that di-(p-chlorophenyl)-cyclopropylmethanol has fungicidal activity against Fusarium culmorum, Alternaria Tenuis, Botrytis cianera, and Phytophthora infestans. Basschots, U.S. Pat. No. 3,287,213, the entire disclosure of which is hereby incorporated by reference. However, in using this active material frequently the cultivated plants are influenced disadvantageously.
It has now been found that benzhydrol derivatives of general formula (I): ##STR2## in which R is an ethyl or more preferably a methyl group and R 1 is a halogen or hydrogen atom exhibit an excellent fungicidal activity for the protection of cultivated plants, especially against Piricularia oryzae in rice, without influencing the useful plants disadvantageously through undesirable side effects.
With the active compounds of formula (I) the fungi present on plants and plant parts (fruits, blossoms, foliage, stems, tubers, roots) and related useful cultivated materials are checked or destroyed, in which case even later growing plant parts remain protected from this type of fungi.
The compounds of formula (I) furthermore can be used as a caustic agent for treating seeds (fruits, tubers, grains) and plant cuttings for protection before fungal infections as well as against phytopathogenic fungi occurring in the soil.
Especially outstanding are compounds of general formula (I) in which R 1 is a fluorine or chlorine and R is the methyl group. However, the preferred compound is α-(1-methyl-cyclopropyl)-4,4'-dichlorobenzhydrol.
Other compounds within formula (I) include
α-(1-methylcyclopropyl)-4,4'-difluorobenzhydrol,
α-(1-methylcyclopropyl)-4,4'-dibromobenzhydrol,
α-(1-ethylcyclopropyl-4,4'-dichlorobenzhydrol,
α-(1-ethylcyclopropyl)-4,4'-dibromobenzhydrol,
α-(1-ethylcyclopropyl)-4,4'-difluorobenzhydrol,
α-(1-methylcyclopropyl)-benzhydrol, and
α-(1-ethylcyclopropyl)-benzhydrol.
The compounds of the invention can be made from the corresponding halobenzenes or dihalobenzenes and the 1-methyl or 1-ethylcyclopropane-carboxylic acid esters in a known manner by means of a Grignard reaction.
The cyclopropylcarboxylic acid ester starting materials mentioned can be prepared according to the method described in Cannon et al, J. Amer. Chem. Soc. Vol. 81 pages 1660-1666, the entire disclosure of which is hereby incorporated by reference and relied upon.
Unless otherwise indicated all parts and percentages are by weight.
The compositions can comprise, consist essentially of or consist of the stated materials and the processes can comprise, consist essentially of the stated steps with such materials.
The following examples illustrate the invention without limiting it.
DETAILED DESCRIPTION
EXAMPLE 1
There are placed under nitrogen in a 6 liter three neck round bottom flask provided with a stirrer, a gas inlet tube, reflux condenser, inflow funnel and thermometer 192 grams of magnesium shavings.
There is prepared a solution of 1176 grams of 1,4-dichlorobenzene in 2.5 liters of tetrahydrofuran. About 200 ml of this solution were added to the magnesium shavings. There were added thereto 10 ml of ethyl bromide under stirring. After several minutes the reaction started. The remainder of the dichlorobenzene solution was then added in such manner that the mixture boiled continuously. The mixture was heated subsequently for 2 hours.
To the Grignard solution obtained there were dropped in under reflux 533.5 grams of 1-methylcyclopropane carboxylic acid ethyl ester (ethyl 1-methylcyclopropylcarboxylate). Subsequently the mixture was heated under reflux at boiling for a further 2 hours.
Then the mixture was cooled and poured on a mixture of 2 kg of ice and 500 grams of glacial acetic acid. The suspension obtained was extracted with toluene. The extract was dried with sodium sulfate and evaporated in vacuo. The oily residue was distilled in a high vacuum. 1-Methylcyclopropyl-bis-(4-chlorophenyl)-carbinol=(bis-(p-chlorophenyl)-1-methylcyclopropyl-methanol) distilled at B.P. 0 .9 mm 180°-182° C.
Amount: 822.8 grams=67% of theory Yellow Oil.
Analysis: C 17 H 16 Cl 2 O (Mol. Wt. 307), Calculated: C 66.4, H 5.2, Cl 23.1, Found: 66.2, 5.1, 23.0.
EXAMPLE 2
70 grams of 1-fluoro-4-bromobenzene were dissolved in 300 ml of diethylether and there was produced therefrom the corresponding Grignard compound with 9.6 grams of magnesium shavings. There was dropped into this solution under reflux 26.9 grams of ethyl 1-methylcyclopropylcarboxylate. The mixture was stirred subsequently for a further 2 hours. The mixture was poured on ice and neutralized with dilute hydrochloric acid. The ether containing solution was evaporated. There remained behind a light brown oil which was distilled in a vacuum. At B.P. 1 141°-143° C. there distilled an almost colorless oil.
Amount: 38.5 grams, corresponding to 70.25% of Theory, α-(1-Methylcyclopropyl)-4,4'-difluorobenzhydrol.
Analysis: C 17 H 16 OF 2 (Mol. Wt. 274), Calculated: C 74.5, H 5.8, F 13.8, Found: 74.2, 5.7, 13.6.
EXAMPLE 3
94.9 grams of 1,4-dibromobenzene were dissolved in 400 ml of diethyl ether and there was produced the corresponding Grignard compound therefrom with 9.6 grams of magnesium shavings. This solution was subsequently reacted with 26.9 grams of ethyl 1-methylcyclopropylcarboxylate at about 30° C. and subsequently worked up as described in Example 2. The thus obtained light red oil was distilled in a vacuum at B.P. 0 .5 187°-189° C.
Amount: 45.8 grams, corresponding to 58.1% of Theory α-(1-Methylcyclopropyl)-4,4'-dibromobenzhydrol.
Analysis: C 17 H 16 OBr 2 (Mol. Wt. 394), Calculated: C 51.8, H 4.1, Br 40.6, 51.7, 4.0, 40.3.
The compounds of formula I can be used alone or together with suitable carriers and/or other additives. Suitable carriers and additives can be solid or liquid and correspond to the customary materials in the formulation art, as e.g. natural or regenerated mineral materials, solvents, dispersing agents, wetting agents, adhesives, thickeners, binders or fertilizers.
As carriers there can be used for example kaolin, talcum, Bolus albus, loess, chalk, limestone, attapulgus clay, dolomite, diatomaceous earth, precipitated silica, alkaline earth metal silicates, sodium and potassium aluminum silicate (feldspar and mica), calcium and magnesium oxide, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate and urea, ground plant products such as ground grain, cottonseed hull meal, wood flour, nut sheet flour, powdered cellulose, activated carbon or mixtures.
As adhesives there can be used for example olein-lime mixture, cellulose derivatives (methyl cellulose, carboxymethyl cellulose). As wetting agents or tensides there can be used for example soaps, sulfonated fats, fatty acid esters and fatty alcohol sulfonates, quaternary ammonium compounds of relatively high molecular weight and non-ionic emulsifiers such as condensation products of fatty alcohols with ethylene oxide, e.g. with 5-20 ethylene oxide residues per molecule and 8-18 carbon atoms in the fatty alcohol portion (e.g. stearyl alcohol), hydroxyethylene glycol ethers of mono and dialkyl phenols with 5 to 20 ethylene oxide residues per molecule and 8-9 carbon atoms in the alkyl group of the phenol (e.g. p-nonyl phenol), alkali and alkaline earth metal salts of lignin sulfonic acid (e.g. sodium ligninsulfonate), polyethylene glycol, alkali metal salts of the alkyl and alkylaryl sulfonates, such as the sodium salt; alkyl sulfates; alkylamide sulfonates, including fatty methyl taurides; the alkylaryl polyether alcohols.
The content of active material in fungicidal compositions is between 0.1 and 99%, especially between 0.1 and 95%. The content of solid and/or liquid additives is 1 to 99.9%, preferably 5 to 99.9%. When a tenside is used its content is advantageously between 0.1-25%.
For application the compounds of formula (I) can be worked up in the following form for application (whereby the weight percentages given in parantheses represent preferred amount of material):
Solid forms for working up: dusts and strewing agent (up to 10%) granulates, encapsulated granulates, impregnated granulates and homogeneous granulates, pellets (granules) 1 to 80%.
Liquid forms for working up.
(a) Dispersible active material concentrates in water:
wettable powders and pastes (25-90% in the commercial package, 0.01 to 15% in solution ready for use);
emulsions and solution concentrates (10 to 50%; 0.01 to 15% in solution ready for use)
(b) solutions (0.1 to 20%); aerosols.
The active material of formula (I) of the present invention for example can be formulated as follows:
Dusts
For the production of an (a) 5% and (b) 2% dust there are used the following materials:
______________________________________(a) Active material 5 parts Talcum 9 parts(b) Active material 2 parts Highly dispersed silica 1 part Talcum 97 parts______________________________________
The active material is mixed with the carriers and ground and can be used in this form as a dust.
Granulate
For the production of a 5% granulate there are used the following materials:
______________________________________Active material 5 partsEpoxidized plant oil (e.g. 0.25 partepoxidized soybean oil)cetyl polyglycol ether 0.25 partspolyethylene glycol 3.5 partsKaolin (particle size 0.3-0.8 mm) 91 parts______________________________________
The active material is mixed with the epoxidized plant oil and dissolved in 6 parts of acetone, hereupon there are added polyethylene glycol and cetyl polyglycol ether. The thus obtained solution is sprayed on kaolin, and subsequently the acetone is evaporated in a vacuum. This type of microgranulate is used advantageously for combatting earth fungi.
Wettable Powder
For the production of an (a) 70%, (b) 40%, (c) and (d) 25% and (e) 10% wettable powder there are used the following components:
______________________________________(a) Active material 70 partssodium dibutylnaphthyl sulfonate 5 partsnaphthalenesulfonic acid-phenolsulfonic 3 partsacid-formaldehyde condensate 3:2:1Kaolin 10 partsChampagne chalk 12 parts(b) Active material 40 partssodium ligninsulfonate 5 partssodium dibutylnaphthalenesulfonate 1 partsilica 54 parts(c) Active material 25 partsCalcium ligninsulfonate 4.5 partsChampagne chalk/hydroxyethyl cellulose 1.9 partsmixture (1:1)sodium dibutylnaphthalenesulfonate 1.5 partssilica 19.5 partsChampagne chalk 19.5 partsKaolin 28.1 parts(d) Active material 25 partsIsooctylphenoxy-polyoxyethylene ethanol 2.5 partsChampagne chalk/hydroxyethyl cellulose 1.7 partsmixture (1:1)sodium aluminum silicate 8.3 partsKieselguhr 16.5 partsKaolin 46 parts(e) Active material 10 partsmixture of the sodium salt of saturated 3 partshigher fatty alcohol sulfatesnaphthalenesulfonic acid-formaldehyde 5 partscondensateKaolin 82 parts______________________________________
The active material is intensively mixed in suitable mixers with the additive materials and ground on corresponding mills and rolls. There are obtained wettable powders of advantageous wettability and suspensibility which are diluted with water to suspensions of the desired concentration and particularly permit use for application to leaves.
Emulsifiable Concentrates
The following materials are used to produce a 25% emulsifiable concentrate
______________________________________Active Material 25 partsEpoxidized plant oil 2.5 partsAlkylarylsulfonate/fatty alcohol- 10 partspolyglycol ether mixturedimethyl formamide 5 partsXylene 57.5 parts______________________________________
There can be produced from such concentrates by dilution with water emulsions of the desired concentration which are particularly suited for application to leaves.
It goes without saying that to broaden their spectrum of the activity the compounds of formula (I) adjusted to the given circumstances can be employed together with other suitable pesticides or plant growth promoting active materials. As the mixing partner there can be used, depending on the area of use, for example the active materials set forth in German OS No. 2506598 pages 6 to 12. The entire disclosure of the German OS is hereby incorporated by reference and relied upon. Thus there can be used for example elemental sulfur, ammonium polysulfide, barium polysulfide, sodium polysulfide, calcium polysulfide, calcium thiosulfate, calcium hypochlorite, boric acid, sodium tetraboride decahydrate (borax), zinc chloride, magnesium borate, nickel sulfate, potassium chromate, lead arsenate, cadmium chloride, cadmium carbonate, copper (I) oxide (Kupferox 10), Bordeaux liquor, copper (II) sulfate pentahydrate, fasic copper (II) chlroide, copper phosphate, tribasic copper (II) sulfate, basic copper (II) carbonate, copper (II)-dihydrazine sulfate, copper ammine complex, copper (II) sulfate-ammonium carbonate mixture, copper (II) chloride-basic copper (II) sulfate mixture, basic copper (II) carbonate-zinc salt mixture, copper (II)-zinc chromate complex, copper (II)-zinc-cadmium-calcium-chromate complex, copper (II) salt of oleic acid, copper (II) salts of fatty acids, e.g. stearic acid, copper (II) salt of naphthenic acid, copper (II) salt of 8-hydroxyquinoline, copper (II) salt of 1,2-naphtho-quinone oxime-(2), copper (II) salt of 3-phenylsalicylate, bis-(tri-n-butyltin) oxide, triphenyltin hydroxide, triphenyltin acetate, bis-(tributyltin) succinate, mercury (I) chloride (calomel), mercury (I) chloride, mercury (II) oxide, mercury-zinc chromate complex, mercury (II) acetate, ethyl mercury chloride, 2-hydroxyethyl mercury acetate, ethyl mercury isothiocyanate, 3-ethoxypropyl mercury bromide, chloromethoxypropyl mercury acetate, methoxyethyl mercury chloride, 2-methoxyethyl mercury silicate, bis-(methyl mercury) sulfate, bis-(methyl mercury) ammonium acetate, ethyl mercury acetate, 2-methoxyethyl mercury acetate, ethyl mercury phosphate, isopropylmethyl mercury acetate, methyl mercury cyanide, methyl mercury benzoate, N-cyano-N' -(methyl mercury) guanidine, methyl mercury pentachlorophenolate, ethyl mercury-2,3-dihydroxypropyl mercaptide, methyl mercury-8-hydroxyquinolate, N-(methyl mercury)-1,4,5,6,7-hexachlorobicyclo-[2.2.1]-hept-5-ene-2,3-dicarboximide, N-(ethyl mercury)-1,4,5,6,7-hexachlorobicyclo-[2.2.1]-hepten-2,3-dicarboximide, sodium salt of ethyl mercury thiosalicylate, N-(ethyl mercury)-p-toluenesulfonanilide, phenyl mercury acetate, phenyl mercury propionate, phenyl mercury triethanol ammonium acetate, phenyl mercury urea, N-(phenyl mercury)-1,4,5,6,7,7-hexachlorobicyclo-([2.2.1]) hept-5-en-2,3-dicarboximide, phenyl mercury dimethyl dithiocarbomate, phenyl mercury formamide, phenyl mercury chloride, phenyl mercury acetate, phenyl mercury benzoate, phenyl mercury borate, phenyl mercury hydroxide, phenyl mercury iodide, basic phenyl mercury nitrate, basic phenyl mercury monoethanol amine acetate, phenyl mercury salicylate, hydroxy mercury chlorophenol, hydroxy mercury trichlorophenol, hydroxy mercury nitrophenol, N-phenyl mercury ethylenediamine, phenyl mercury monoethanol ammonium acetate, pyridyl mercury acetate, diphenyl mercury-8-hydroxyquinolate, mercury (II) complex with organic phosphates, mixture of methyl mercury-2,3-dihydroxy-propyl mercaptide and methyl mercury acetate, mixture of ethyl mercury-2,3-dihydroxypropyl-mercaptide and ethyl mercury acetate, mixture of hydroxy-mercury chlorophenol and hydroxymercury nitrophenol, mercury-cadmium-organic complexes, cadmium succinate, cadmium-di-n-propyl xanthogenate, cadmium-8-hydroxyquinolate, phenylamino cadmium acetate, phenylamino cadmium dilactate, methyl arsinosulfide, zinc octate, zinc oleate, formalin, paraformaldehyde, acrolein, methyl bromide, methyl isothiocyanate, tetraiodoethylene, 1,3-dichloropropylene and related chlorinated C 3 -hydrocarbons, 1-chloro-3-bromopropene-(1), trans-1,4-dibromobutene-(2), 1,3-dichloropropene-(1), 1-chloro-2-nitropropane, 2-chloro-1-nitropropane trichloronitromethane, dichlorotetrafluoroacetone, sodium salt of propionic acid, calcium propionate, chlorofumaric acid-bis-β-chloroethyl ester, sorbic acid and its potassium salt, 2-propen-1,1-diol acetate, 2-aminobutane, dodecylguanidine acetate, dodecylguanidine phthalate, α-chloroacetyl-1,3-aminopropionitrile, α-bromoacetyl valinamide, 1,2-dichloro-1-(methylsulfonyl)-ethylene, 1,2-dichloro-1-(butylsulfonyl)-ethylene, trans-1,2-bis-(n-propylsulfonyl)-ethylene, p-dichlorobenzene, hexachlorobenzene, 1,2,4,5-tetrachloro-4-nitrobenzene, pentachloronitrobenzene, 1,3,5-trichloro-2,4,6-trinitrobenzene, isomeric mixture of 1,3,4-trichloro-2,6-dinitrobenzene and 1,2,3-trichloro-4,6-dinitrobenzene, 2,4,5,6-tetrachloroisophthalonitrile, 2,4-dinitrophenyl thiocyanide, diphenyl, o-nitrodiphenyl, 1-chloro-2,4-dinitronaphthalene, acenaphthene, 2,4,6-trichlorophenol, 2,4,5-trichlorophenol, 2,4,5-trichlorophenyl acetate, 2,4,5-trichlorophenyl chloroacetate, zinc salt of trichlorophenol, m-cresyl acetate, 2,3,4,6-tetrachlorophenol, pentachlorophenol, o-dihydroxybenzene, 2,4-dihydroxy-n-hexylbenzene, 2-phenylphenol, 3,5-dibromosalicylaldehyde, 2-benzyl-4-chlorophenol, 2,2'-dihydroxy-5,5'-dichlorodiphenyl methane, 2,2'-dihydroxy-3,3',5,5',6,6'-hexachloro-diphenylmethane, 2,2'-dihydroxy-5,5'-dichloro-diphenyl sulfide, 2,2'-dihydroxy-3,3',5,5'-tetrachloro-diphenyl sulfide, 2,2' -dihydroxy-3,3',5,5'-tetrachloro-diphenyl sulfide disodium salt, 4-chloro-o-phenylphenol, 1,4-dichloro-2,5-dimethoxybenzene, salicylanilide, bismuth salicylate, trifluoromethylsalicylanilide halogenated with chlorine or bromine, brominated salicylanilide, (3,5-dimethyl-4-chlorophenoxy)ethanol, 2-(1-methyl-n-propyl)-4,6-dinitrophenyl-2-methyl crotonate, 2-(1-methyl-n-propyl)-4,6-dinitrophenylisopropyl crotonate, 2-(1-methyl-n-heptyl)-4,6-dinitro-phenyl crotonate, methyl-2,6-dinitro-4(1-ethylhexyl)-phenylcarbonate plus methyl-3,6-dinitro-4-(1-propyl-pentyl) phenyl carbonate, 4-nonyl-2,6-dinitrophenyl butyrate, 5-methyl-2-(1-methyl-n-heptyl)-4,6-dinitro-phenyl thiocarbonate, 2,6-dichloro-4-nitroaniline, 2-cyanoethyl-N-phenyl carbamate, propynyl-N-phenyl carbamate, o-(2-bromoacetoxy)-acetanilide, 2,3,5,6-tetrachlorobenzoquinone (1,4), 2,3-dichloro-naphthoquinone (1,4), 2-chloro-3-acetamino-naphthoquinone (1,4), 4-methyl-2,3,5,10-tetrahydro-3,5,10-trioxo-4H4-H-naphtho(1,3,-b)-1,4-triazine, 2,3,6,7-tetrachloro-4a,8a-epoxy-1,2,3,4,4a,8a-hexahydro-1,4-methanonaphthalene,5,8-dione, quinoximobenzoyl hydrazone, N-(trichloromethylthio) phthalimide, N-(trichloromethylthio) cyclohex-4-en-1,2-dicarboximide, N-(1,1,2,2-tetrachloroethylthio) cyclohex-4-en-1,2-dicarboximide, N-methanesulfonyl-N-trichloroethylthio-p-chloroaniline, N'-dichlorofluoromethylthio-N-dimethyl-N'-phenylsulfamide,5-(2-pyridyl-1-oxide)-S'-trichloromethyldisulfide, O,O,O-trimethyl thiophosphate, O,O-diethyl-phthalimido phosphonothioate, 5-amino-bis-(dimethylamido) phosphinyl-3-phenyl-1,2,4-triazole, 5-methylamino-bis-(dimethylamido) phosphinyl-3-phenyl-1,2,4-triazole, O,O-diethyl-O-2-pyrazinyl phosphorothioate, O-ethyl-S,S-diphenyldithiophosphate, O-ethyl-S-benzyl phenyl dithiophosphonate, O,O-diethyl-S-benzylthiophosphate, zinc salt of dithiocarbazinic acid, sodium-N-methyl dithiocarbamate, sodium-N-methoxyethyl dithiocarbamate, sodium N,N-diethyl dithiocarbamate, ammonium N,N-dimethyl dithiocarbamate, zinc N,N-dimethyl dithiocarbamte, iron-N,N-dimethyl dithiocarbamate, copper-N,N-dimethyl dithiocarbamate, disodium ethylene-1,2-bis dithiocarbamate, zinc-ethylene-1,2-bis-dithiocarbamate, iron ethylene-1,2-bis dithiocarbamate, manganese (II)-ethylene-1,2-bis-dithiocarbamate, calcium-ethylene-1,2-bis-dithiocarbamate, ammonium-ethylene-1,2-bis-dithiocarbamate, zinc-propylene-1,2-bis dithiocarbamate, bis (dimethylthiocarbamyl)-ethylene-1,2-bis-dithiocarbamate, complex consisting of manganese (II)-ethylene-1,2-bis-dithiocarbamate and Mancozeb, tetraethylthiuram monosulfide, bis-(N,N-dimethyl-dithiocarbamyl mercapto)-methylarsine, tetramethylthuiram disulfide, bipyrridyl thiuramdisulfide, N,N'-bis-(dimethylamino)thuiram disulfide, polyethylene thiuramdisulfide, complex consisting of zinc ethylene-1,2-bis-dithio-carbamate and polyethylene thiuramdisulfide, bis-(3,4-dichloro-2(5)-furanoyl) ether (mucochleric anhydride), 2-methoxymethyl-5-nitrofurane, 5-nitrofurfuraldoxime, 5-nitro-furfuryl amidoxime, 1-hydroxy-3-acetyl-6-methyl-cyclohexen-(5)-dione-(2,4) (dehydroacetic acid), 3-[-3,5-dimethyl-2-hydroxycyclohexyl)-2-hydroxyethyl]-glutarimid(cycloheximido) phthalimide, pyridin-2-thiol-1-oxide or 1-hydroxypridine-2-thione, zinc salt of pyridine-2-thiol-1-oxide, manganese (II) salt of pyridine-2-thiol-1-oxide, S-1(1-oxido-2-pyridyl) isothiuronium chloride, α,α-bis(4-chlorophenyl)-3-pyridine methanol, 8-hydroxyquinoline, 8-hydroxyquinoline sulfate, benzoyl-8-hydroxyquinoline salicylate, 3-(2-methylpiperidino)propyl-3,4-dichloro-benzoate, 6-ethoxy-1,2-dihydro-2,2,4-methylquinoline, N-lauryl isoquinolium bromide, 9-(p-n-hexyloxyphenyl)-10-methyl-acridinium chloride, 9-(p-n-hexyloxyphenyl)-10-methyl acridinium-p-toluenesulfonate, 2-n-heptadecylimidazolidine acetate, 1-hydroxyethyl-2-heptadecylimidazolidine, 1-phenyl-3,5-dimethyl-4-nitrosopyrazole, 1-p-chlorophenyl-3,5-dimethyl-4-nitrosopyrazole, 1-p-sulfacylphenyl-3,5-dimethyl-4-nitrosopyrazole, N-(1-phenyl-2-nitropropyl) piperazine, 2-dimethylamino-5-methyl-5-n-butyl-4-hydroxy-pyrimidine, N-dodecyl-1,4,5,6-tetrahydropyrimidine, N-dodecyl-2-methyl-1,4,5,6-tetrahydropyrimidine, 2-n-heptadecyltetrahydropyrimidine, 1-(4-amino-4-propyl-5-pyrimidyl-methyl)-2-methyl pyridinium chloride hydroxy chloride, 2-(2'-furyl)-benzimidazole, 3-dodecyl-1-methyl-2-phenylbenzimidazolium-ferricyanide, methyl-N-benzimidazol-2-yl-N-(butylcarbamoyl) carbamate, 2-(o-chloroanilino)-4,6-dichloro-sym.triazine, 2-ethylamino-6-methyl-5-n-butyl-4-hydroxy pyrimidine, 5-chloro-4-phenyl-1,2-dithiol-3-one, 2,3-dicyano-1,4-dithiaanthraquinone, 2-(4-thiazolyl)-benzimidazole, 4-(2-chlorophenylhydrazono)-3-methyl-5-isoxazolone, thiazolidinen-4-thione-(2), 3-(p-chlorophenyl)-5-methylrhodanine, 3,5-dimethyltetrahydro-1,3,5-thiadiazin-2-thione, 3,3'-ethylene-bis-(tetrahydro-4,6-dimethyl)-2H-1,3,5-thiadiazin-2-thione),3-benzylidenamino-4-phenylthiazolin-7 -thione, zinc salt of 6-chlorobenzothiazol-2-thiol, 6-α-diethylamino-ethoxy-2-dimethylamino-benzothiazole dihydrochloride, monoethanolammoniumbenzothiazole-2-thiol, lauryl pyridinium-5-chloro-2-mercaptobenzothiazole, zinc and sodium salts of 2-mercaptobenzothiazole and dimethylcarbamate, 6-(diethylaminoethoxy)-2-dimethylaminobenzothiazole dihydrochloride, 3-trichloromethylthiobenzothiazolone, 3-trichloromethylthiobenzoxazolone, 3-(trichloromethyl)-5-ethoxy-1,2,4-thiadiazol, 6-methyl-2-oxo-1,3-dithiolo[4,5-b]-quinoxaline, 2-thio-1,3-dithiolo[4,5-b]-quinoxaline, 2,3-dihydro-5-carboxanilido-6-methyl-1,4-oxathine, 3,3,4,4-tetrachlorotetrahydrothiophen-1,1-dioxide, 2,3-dihydro-5-carboxanilido-6-methyl-1,4-oxathin-4,4-dioxide, ethyl trimethylammonium bromide, n-alkyl(C 12 ,C 14 ,C 16 ) dimethylbenzylammonium chloride, alkenyl dimethyl ethyl ammonium bromide, dialkyldimethylammoniumbromide, alkyldimethylbenzylammonium chloride, alkyl C 9 -C 15 tolylmethyl trimethylammonium chloride, di-isobutylcresoxyethoxyethyldimethylbenzylammonium chloride, p-di-isobutylphenoxyethoxyethyl dimethylammonium chloride, benzoyltrimethyl ammonium bromide, gliotoxin, 2,4-diguanido-3,5,6-trihydroxy-cyclohexyl 5-deoxy-2-O-(2-deoxy-2-methylamino-α-L-glucopyranosyl)-3-C-formyl-3-L-lyxopentofuranoside (streptomycin), 7-chloro-4,6-dimethoxycumaran-3-one-2-spiro-1'-(2'-methoxy-6'-methylcyclohex-2'-en-4'-one) Griseofulvin), 4-dimethylamino-1,4,4α,5,5α6,11,12-octahydro-3,5,6,10,12,12a-hexahydroxy-6-methyl-1,11-dioxo-2-naphthacencarboximide (Oxytetracyclin), 7-chloro-4-dimethylamine-1,4,4α,5,5α,6,11,12-octahydro-3,6,10,12,12 pentahydroxy-6-methyl-1,11-dioxo-2-naphthacencarboximide (Chlorotetracyclin), Pimaricin, Lanomycin, Phleomycin, Kasugamycin, Phytoactin, D(-)-threo-2,2-dichloro-N-[3-hydroxy-α-(hydroxymethyl)-17-p-nitrophenethyl] 9 acetamide, Blasticidiin-S-benzylamino-benzenesulfonate, N-(3-nitrophenyl) itaconimide, phenoxyacetic acid, sodium-p-dimethylaminobenzenediazo sulfonate, acrolein phenylhydrazone, 2-chloroacetaldehyde (2,4-dinitrophenyl)-hydrazone, 2-chloro-3-(tolylsulfonyl)-propionitrile, 1-chloro-2-phenylpentan-diol (4,5)-thione-(3), p-nonylphenoxypolyethylenoxyethanol-iodide complex, (α-nitromethyl)-o-chlorobenzylthioethylamine hydrochloride, 3-(p.t.-butylphenylsulfonyl) acrylonitrile, octachlorocyclohexenone, pentachlorobenzyl alcohol, pentachlorobenzyl acetate, pentachlorobenzaldehyde cyanohydrin, 2-norcamphane methanol, 2,6-bis-(dimethylaminomethyl)-cyclohexanone, decachlorooctahydro-1,3,4-methano-2H-cyclobuta[cd] pentalen-2-one, 1-(3-chloroallyl)-3,5,7-triaza-1-azonia adamantane hydrochloride, coal tar and high oven tar, mixture of nickel sulfate-Maneb, mixture of Maneb-mercaptobenzothiazole, mixture of Zineb-mercaptobenzothiazole, mixture of Zineb-nickel (II) chloride, mixture of Zineb-nickel (II) sulfate, mixture of Ziran-basic copper sulfate, mixture of Ziran-zinc-mercaptobenzothiazole, mixture of Thiram-cadmium chloride hydrate, mixture of Thiram-hydroxymercury chlorophenol, mixture of Thiram-phenyl mercury acetate, mixture of polyethylene-bis-thiramsulfide-copper oxychloride, mixture of methylarsine-bis-(dimethyldithiocarbamate)-Ziram-Thiram, mixture of Folpet-phenylmercuryacetate, mixture of Dodine-Farbam-sulfur, mixture of Dithianone-copper oxychloride, mixture of Dichlone-Farbam-sulfur, mixture of Dinocap-dinitrooctylphenol, mixture of Captan-quintozene-tribasic copper sulfate, mixture of cadmium propionate-phenyl mercury propionate, formaldehyde-urea mixture, mixture of phenylammonium cadmium dilactate-phenyl mercury formamide, and mixture of basic copper sulfate-zinc salt.
EXAMPLE 4
Action Against Piricularia Oryzae On Rice
Rice plants after two weeks cultivation were sprayed with a liquor (0.02% active material) made from a wettable powder of the active material. After 48 hours the treated plants were infected with a konidium suspension of the fungi. After 5 days incubation at 95-100% relative humidity and 24° C. the attack of the fungi was evaluated.
The compound α-(1-methylcyclopropyl)-4,4'-dichlorobenzhydrol showed a very strong plant fungicide activity. At most the attack of the fungi on the treated plants was 0-5% which corresponds to an effective activity of 95-100%.
For comparison in an entirely analogous manner there was used as the active material the compound di-(p-chlorophenyl)-cyclopropylmethanol. It merely showed an unsatisfactory partial activity, i.e. the average attack on the fungi was in the range of 20-50%.
The entire disclosure of German priority application No. P 3206225.7 is hereby incorporated by reference. | There are prepared compounds of the general formula ##STR1## where R is methyl or ethyl and R 1 is halogen or hydrogen. The compounds are useful as fungicides, especially against Piricularia oryzae on rice. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of my copending application Ser. No. 302,567, filed Oct. 30, 1972, which was a continuation-in-part of my then copending application Ser. No. 121,572, filed Mar. 5, 1971 both now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to compositions of matter, and to methods and intermediates for producing them. In particular, the several aspects of this invention relate to novel oxa-phenylene analogs of some of the known prostaglandins, for example prostaglandin E 1 (PGE 1 ), prostaglandin E 2 (PGE 3 ), prostaglandin F 1 (PGF 1 .sub.α and PGF 1 .sub.β), prostaglandin F 2 (PGF 2 .sub.α and PGF 2 .sub.β), prostaglandin A 1 (PGA 1 ), prostaglandin A 2 (PGA 2 ), prostaglandin B 1 (PGB 1 ), prostaglandin B 2 (PGB 2 ), the corresponding PG 3 's, and the dihydro PG 1 derivatives, to novel methods for producing those novel prostaglandin analogs, and to novel chemical intermediates useful in those novel methods.
Each of the above-mentioned known prostaglandins is a derivative of prostanoic acid which has the following structure and atom numbering: ##SPC1##
A systematic name for prostanoic acid is 7-[(2β-octyl)-cyclopent-1α-yl]heptanoic acid.
PGE 1 has the following structure: ##SPC2##
PGF 1 .sub.α has the following structure: ##SPC3##
Pgf 1 .sub.β has the following structure: ##SPC4##
Pga 1 has the following structure: ##SPC5##
Pgb 1 has the following structure: ##SPC6##
Each of the known prostaglandins PGE 2 , PGF 2 .sub.α, PGF 2 .sub.β, PGA 2 , and PGB 2 has a structure the same as that shown for the corresponding PG 1 compound except that in each, C-5 and C-6 are linked with a cis carbon-carbon double bond. For example, PGE 2 has the following structure: ##SPC7##
Each of the known PG 3 prostaglandins has a structure the same as that of the PG 2 compounds except that in each, C-17 and C-18 are linked with a cis carbon-carbon double bond. For example, PGE 3 has the following structure: ##SPC8##
Each dihydro derivative of PGE 1 , PGF 1 .sub.α, PGF 1 .sub.β, PGA 1 , and PGB 1 has a structure the same as that shown for the corresponding PG 1 compound except that in each, C-13 and C-14 are linked with a carbon-carbon single bond. For example, dihydro-PGE 1 has the following structure: ##SPC9##
The prostaglandin formulas mentioned above each have several centers of asymmetry. As drawn, formulas II to IX each represents the particular optically active form of the prostaglandin obtained from certain mammalian tissues, for example, sheet vesicular glands, swine lung, and human seminal plasma, or by reduction or dehydration of a prostaglandin so obtained. See, for example, Bergstrom et al., Pharmacol. Rev. 20, 1 (1968), and references cited therein. The mirror image of each formula represents a molecule of the enantiomer of that prostaglandin. The racemic form of the prostaglandin consists of equal numbers of two types of molecules, one represented by one of the above formulas and the other represented by the mirror image of that formula. Thus, both formulas are needed to define a racemic prostaglandin. See Nature 212, 38 (1966) for discussion of the stereochemistry of the prostaglandins.
In formulas I-IX, as well as in the formulas given hereinafter, broken line attachments to the cyclopentane ring indicate substituents in alpha configuration, i.e., below the plane of the cyclopentane ring. Heavy solid line attachments to the cyclopentane ring indicate substituents in beta configuration, i.e., above the plane of the cyclopentane ring.
Prostaglandins with carboxyl-terminated side chains attached to the cyclopentane ring in beta configuration are also known. These are derivatives of 8-iso-prostanoic acid which has the following formula: ##SPC10##
A systematic name for 8-iso-prostanoic acid is 7-[(2β-octyl)-cyclopent-1β-yl]heptanoic acid.
The side-chain hydroxy at C-15 in formulas II to IX is in alpha (S) configuration. See Nature 212, 38 (1966) for discussion of the stereochemistry of the prostaglandins.
PGE 1 , PGE 2 , dihydro-PGE 1 , and the corresponding PGF.sub.α, PGF.sub.β, PGA, and PGB compounds, and their esters, acylates, and pharmacologically acceptable salts, are extremely potent in causing various biological responses. For that reason, these compounds are useful for pharmacological purposes. See, for example, Bergstrom et al., Pharmacol. Rev. 20, 1 (1968), and references cited therein. A few of those biological responses are stimulation of smooth muscle as shown, for example, by tests of strips of guinea pig ileum, rabbit duodenum, or gerbil colon; potentiation of other smooth muscle stimulants; antilipolytic activity as shown by antagonism of epinephrine-induced mobilization of free fatty acids or inhibition of the spontaneous release of glycerol from isolated rat fat pads; inhibition of gastric secretion in the case of the PGE and PGA compounds as shown in dogs with secretion stimulated by food or histamine infusion; activity on the central nervous system; controlling spasm and facilitating breathing in asthmatic conditions; decreasing blood platelet adhesiveness as shown by platelet-to-glass adhesiveness, and inhibition of blood platelet aggregation and thrombus formation induced by various physical stimuli, e.g., arterial injury, and various biochemical stimuli, e.g., ADP, ATP, serotonin, thrombin, and collagen; and in the case of the PGE and PGB compounds, stimulation of epidermal proliferation and keratinization as shown when applied in culture to embryonic chick and rat skin segments.
Because of these biological responses; these known prostaglandins are useful to study, prevent, control, or alleviate a wide variety of diseases and undesirable physiological conditions in birds and mammals, including humans, useful domestic animals, pets, and zoological specimens, and in laboratory animals, for example, mice, rats, rabbits, and monkeys.
For example, these compounds, and especially the PGE compounds, are useful in mammals, including man, as nasal decongestants. For this purpose, the compounds are used in a dose range of about 10 μg. to about 10 mg. per ml. of a pharmacologically suitable liquid vehicle or as an aerosol spray, both for topical application.
The PGE, PGF.sub.α, PGF.sub.β, and PGA compounds are useful in the treatment of asthma. For example, these compounds are useful as bronchodilators or as inhibitors of mediators, such as SRS-A, and histamine which are released from cells activated by an antigen-antibody complex. Thus, these compounds control spasm and facilitate breathing in conditions such as bronchial asthma, bronchitis, bronchiectasis, pneumonia and emphysema. For these purposes, these compounds are administered in a variety of dosage forms, e.g., orally in the form of tablets, capsules, or liquids; rectally in the form of suppositories; parenterally, subcutaneously, or intramuscularly, with intravenous administration being preferred in emergency situations; by inhalation in the form of aerosols or solutions for nebulizers; or by insufflation in the form of powder. Doses in the range of about 0.01 to 5 mg. per kg. of body weight are used 1 to 4 times a day, the exact dose depending on the age, weight, and condition of the patient and on the frequency and route of administration. For the above use these prostaglandins can be combined advantageously with other anti-asthmatic agents, such as sympathomimetics (isoproterenol, phenylephrine, ephedrine, etc); xanthine derivatives (theophylline and aminophylline); and corticosteroids (ACTH and predinisolone). Regarding use of these compounds see South African Pat. No. 681,055.
The PGE and PGA compounds are useful in mammals, including man and certain useful animals, e.g., dogs and pigs, to reduce and control excessive gastric secrection, thereby reducing or avoiding gastrointestinal ulcer formation, and accelerating the healing of such ulcers already present in the gastrointestinal tract. For this purpose, the compounds are injected or infused intravenously, subcutaneously, or intramuscularly in an infusion dose range about 0.1 μg. to about 500 μg. per kg. of body weight per minute, or in a total daily dose by injection or infusion in the range about 0.1 to about 20 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful whenever it is desired to inhibit platelet aggregation, to reduce the adhesive character of platelets, and to remove or prevent the formation of thrombi in mammals, including man, rabbits, and rats. For example, these compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent post-operative thrombosis, to promote patency of vascular grafts following surgery, and to treat conditions such as atherosclerosis, arteriosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia. For these purposes, these compounds are administered systemically, e.g., intravenously, subcutaneously, intramuscularly, and in the form of sterile implants for prolonged action. For rapid response, especially in emergency situations, the intravenous route of administration is preferred. Doses in the range about 0.005 to about 20 mg. per kg. of body weight per day are used, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The PGE, PGF.sub.α, and PGF.sub.β compounds are especially useful as additives to blood, blood products, blood substitutes, and other fluids which are used in artificial extracorporeal circulation and perfusion of isolated body portions, e.g., limbs and organs, whether attached to the original body, detached and being preserved or prepared for transplant, or attached to a new body. During these circulations and perfusions, aggregated platelets tend to block the blood vessels and portions of the circulation apparatus. This blocking is avoided by the presence of these compounds. For this purpose, the compound is added gradually or in single or multiple portions to the circulating blood, to the blood of the donor animal, to the perfused body portion, attached or detached, to the recipient, or to two or all of those at a total steady state dose of about 0.001 to 10 mg. per liter of circulating fluid. It is especially useful to use these compounds in laboratory animals, e.g., cats, dogs, rabbits, monkeys, and rats, for these purposes in order to develop new methods and techniques for organ and limb transplants.
PGE compounds are extremely potent in causing stimulation of smooth muscle, and are also highly active in potentiating other known smooth muscle stimulators, for example, oxytocic agents, e.g., oxytocin, and the various ergot alkaloids including derivatives and analogs thereof. Therefore, PGE 2 , for example, is useful in place of or in combination with less than usual amounts of these known smooth muscle stimulators, for example, to relieve the symptoms of paralytic ileus, or to control or prevent antonic uterine bleeding after abortion or delivery, to aid in expulsion of the placenta, and during the puerperium. For the latter purpose, the PGE compound is administered by intravenous infusion immediately after abortion or delivery at a dose in the range about 0.01 to about 50 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, subcutaneous, or intramuscular injection or infusion during puerperium in the range 0.01 to 2 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful in place of oxytocin to induce labor in pregnant female animals, including man, cows, sheep, and pigs, at or near term, or in pregnant animals with intrauterine death of the fetus from about 20 weeks to term. For this purpose, the compound is infused intravenously at a dose of 0.01 to 50 μg. per kg. of body weight per minute until or near the termination of the second stage of labor, i.e., expulsion of the fetus. These compounds are especially useful when the female is one or more weeks post-mature and natural labor has not started, or 12 or 60 hours after the membranes have ruptured and natural labor has not yet started. An alternative route of administration is oral.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful for controlling the reproductive cycle in ovulating female mammals, including humans and animals such as monkeys, rats, rabbits, dogs, cattle, and the like. By the term ovulating female mammals is meant animals which are mature enough to ovulate but not so old that regular ovulation has ceased. For that purpose PGF 2 .sub.α, for example, is administered systemically at a dose level in the range 0.01 mg. to about 20 mg. per kg. of body weight of the female mammal, advantageously during a span of time starting approximately at the time of ovulation and ending approximately at the time of menses or just prior to menses. Intravaginal and intrauterine are alternative routes of administration. Additionally, expulsion of an embryo or a fetus is accomplished by similar administration of the compound during the first third of the normal mammalian gestation period.
As mentioned above, the PGE compounds are potent antagonists of epinephrine-induced mobilization of free fatty acids. For this reason, this compound is useful in experimental medicine for both in vitro and in vivo studies in mammals, including man, rabbits, and rats, intended to lead to the understanding, prevention, symptom alleviation, and cure of diseases involving abnormal lipid mobilization and high free fatty acid levels, e.g., diabetes mellitus, vascular diseases, and hyperthyroidism.
The PGA compounds and derivatives and salts thereof increase the flow of blood in the mammalian kidney, thereby increasing volume and electrolyte content of the urine. For that reason, PGA compounds are useful in managing cases of renal dysfunction, especially those involving blockage of the renal vascular bed. Illustratively, the PGA compounds are useful to alleviate and correct cases of edema resulting, for example, from massive surface burns, and in the management of shock. For these purposes, the PGA compounds are preferably first administered by intravenous injection at a dose in the range of 10 to 1000 μg. per kg. of body weight or by intravenous infusion at a dose in the range 0.1 to 20 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, intramuscular, or subcutaneous injection or infusion in the range 0.05 to 2 mg. per kg. of body weight per day.
The PGE and PGB compounds promote and accelerate the growth of epidermal cells and keratin in animals, including humans, useful domestic animals, pets, zoological specimens, and laboratory animals. For that reason, these compounds are useful to promote and accelerate healing of skin which has been damaged, for example, by burns, wounds, and abrasions, and after surgery. These compounds are also useful to promote and accelerate adherence and growth of skin autografts, especially small, deep (Davis) grafts which are intended to cover skinless areas by subsequent outward growth rather than initially, and to retard rejection of homografts.
For these purposes, these compounds are preferably administered topically at or near the cite where cell growth and keratin formation is desired, advantageously as an aerosol liquid or micronized powder spray, as an isotonic aqueous solution in the case of wet dressings, or as a lotion, cream, or ointment in combination with the usual pharmaceutically acceptable diluents. In some instances, for example, when there is substantial fluid loss as in the case of extensive burns or skin loss due to other causes, systemic administration is advantageous, for example, by intravenous injection or infusion, separate or in combination with the usual infusions of blood, plasma, or substitutes thereof. Alternative routes of administration are subcutaneous or intramuscular near the site, oral, sublingual, buccal, rectal, or vaginal. The exact dose depends on such factors as the route of administration, and the age, weight, and condition of the subject. To illustrate, a wet dressing for topical application to second and/or third degree burns of skin area 5 to 25 square centimeters would advantageously involve use of an isotonic aqueous solution containing 1 to 500 μg./ml. of the PGB compound or several times that concentration of the PGE compound. Especially for topical use, these prostaglandins are useful in combination with antibiotics, for example, gentamycin, neomycin, polymyxin B, bacitracin, spectinomycin, and oxytetracycline, with other antibacterials, for example, mafenide hydrochloride, sulfadiazine, furazolium chloride, and nitrofurazone, and with corticoid steroids, for example, hydrocortisone, prednisolone, methylprednisolone, and fluprednisolone, each of those being used in the combination at the usual concentration suitable for its use alone.
The PGE and PGF compounds are useful in causing cervical dilation in pregnant and nonpregnant female mammals for purposes of gynecology and obstetrics. In labor induction and in clinical abortion produced by these compounds, cervical dilation is also observed. In cases of infertility, cervical dilation produced by PGE and PGF compounds is useful in assisting sperm movement to the uterus. Cervical dilation by prostaglandins is also useful in operative gynecology such as D and C (Cervical Dilation and Uterine Curettage) where mechanical dilation may cause performation of the uterus, cervical tears, or infections. It is also useful in diagnostic procedures where dilation is necessary for tissue examination. For these purposes, the PGE and PGF compounds are administered locally or systemically. PGE 2 , for example, is administered orally or vaginally at doses of about 5 to 50 mg. per treatment of an adult female human, with from one to five treatments per 24 hour period. PGE 2 is also administered intramuscularly or subcutaneously at doses of about one to 25 mg. per treatment. The exact dosages for these purposes depend on the age, weight, and condition of the patient or animal.
The PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB compounds are useful in reducing the undesirable gastrointestinal effects resulting from systemic administration of anti-inflammatory prostaglandin synthetase inhibitors, and are used for that purpose by concomitant administration of the prostaglandin and the anti-inflammatory prostaglandin synthetase inhibitor. See Partridge et al., U.S. Pat. No. 3,781,429, for a disclosure that the ulcerogenic effect induced by certain non-steroidal anti-inflammatory agents in rats is inhibited by concomitant oral administration of certain prostaglandins of the E and A series, including PGE 1 , PGE 2 , PGE 3 , 13,14-dihydro-PGE 1 , and the corresponding 11-deoxy-PGE and PGA compounds.
The anti-inflammatory synthetase inhibitor, for example, indomethacin, aspirin, or phenylbutazone is administered in any of the ways known in the art to alleviate an inflammatory condition, for example, in any dosage regimen and by any of the known routes of systemic administration. The prostaglandin is administered along with the anti-inflammatory prostaglandin synthetase inhibitor either by the same route of administration or by a different route. For example, if the anti-inflammatory substance is being administered orally, the prostaglandin is also administered orally or, alternatively, is administered rectally in the form of a suppository or, in the case of women, vaginally in the form of a suppository or a vaginal device for slow release, for example as described in U.S. Pat. No. 3,545,439. Alternatively, if the anti-inflammatory substance is being administered rectally, the prostaglandin is also administered rectally or, alternatively, orally or, in the case of women vaginally. It is especially convenient when the administration route is to be the same for both anti-inflammatory substance and prostaglandin, to combine both into a single dosage form.
The dosage regimen for the prostaglandin in accord with this treatment will depend upon a variety of factors, including the type, age, weight, sex and medical condition of the mammal, the nature and dosage regimen of the anti-inflammatory synthetase inhibitor being administered to the mammal, the sensitivity of the particular individual mammal to the particular synthetase inhibitor with regard to gastrointestinal effects, and the particular prostaglandin to be administered.
SUMMARY OF THE INVENTION
It is a purpose of this invention to provide novel oxa-phenylene prostaglandin analogs, and process for making them.
The novel prostaglandin analogs of this invention each have an oxa oxygen (--O--) and a divalent phenylene moiety ##SPC11##
in the carboxyl-terminated side chain of the prostanoic acid structure (I) or the 8-iso-prostanoic acid structure (X). These divalent groups are located between the carboxyl group and the cyclopentane ring, and are either in addition to the six methylene portions of said chain or in place of one to five of said methylene portions. Bonding to the phenylene ring is either ortho, meta, or para. The oxa group is between the phenylene moiety and the carboxyl group.
Some of the novel prostaglandin analogs of this invention also have, in addition, a benzene ring as part of the C-13 to C-20 chain of the prostanoic acid structure (I) or 8-iso-prostanoic acid structure (X). That benzene ring is present as a substituted or unsubstituted phenyl moiety attached as a substituent to one of the methylenes between C-15 and the terminal methyl of the prostanoic acid or 8-isoprostanoic acid structure. Alternatively, the substituted or unsubstituted phenyl moiety is attached to the terminal or omega carbon of the C-16 to C-20 portion of the chain, replacing one of the hydrogens of the terminal methyl, the entire terminal methyl, or the terminal methyl plus one to four of the methylenes adjacent to that terminal methyl.
For example, five of the novel prostaglandin analogs of this invention are represented by the formulas: ##SPC12##
Based on its relationship to PGE 1 and prostanoic acid, the compound of formula XI is named 3-oxa-4,5-inter-p-phenylene-PGE 1 . Similarly, the compound of formula XII is named 15(R)-3-oxa-3,6-inter-m-phenylene-4,5-dinor-13,14-dihydro-PGF 1 .sub..alpha., the compound of formula XIII is named 8-iso-3-oxa-19-phenyl-4,7-inter-m-phenylene-5,6-dinor-PGA 1 , the compound of the formula XIV is named 3-oxa-16-(4-chloro-phenyl)-3,5-inter-o-phenylene-4,17,18,19,20-pentanor-PGF 2 .sub.β, and the compound of formula XV is named 5,6-dehydro-4-oxa-4,5-inter-m-phenylene-PGB 2 .
These names for the compounds of formulas XI to XV are typical of the names used hereinafter for the novel compounds of this invention. These names can better be understood by reference to the structure and numbering system of prostanoic acid (Formula I, above). That formula has seven carbon atoms in the carboxy-terminated chain and eight carbon atoms in the hydroxy-containing chain. In these names, "3-oxa" and "4-oxa" indicate an oxa oxygen (--O--) in place of the 3-methylene and 4-methylene, respectively of the PG compound.
The use of "nor," "dinor," "trinor," "tetranor," "pentanor," "hexanor," and the like in the names for the novel compounds of this invention indicates the absence of one or more of the chain carbon atoms and the attached hydrogen atoms. The number or numbers in front of nor, dinor, etc., indicate which of the original prostanoic acid carbon atoms are missing in the named compound.
Each of the names of the novel compounds of this invention contains (inter-p-phenylene), (inter-m-phenylene), or (inter-o-phenylene), preceded by two numbers. That indicates that p-phenylene, m-phenylene, or o-phenylene has been inserted between (inter) the two carbon atoms so numbered in the formula of prostanoic acid.
Thus, formula XIII differs from prostanoic acid in that an oxa oxygen replaces carbon 3, carbons 5 and 6 of prostanoic acid are missing, m-phenylene has been inserted between carbons 4 and 7 of prostanoic acid, and a phenyl has been attached to carbon 19 of prostanoic acid. Formula XIII also, of course, is an A type prostaglandin, having a carbonyl oxygen and a 10:11 double bond.
Novel compounds of this invention with the carboxyl-terminated chain attached to the cyclopentane ring in beta configuration are 8-iso compounds (formula X), and are so designated by using "8-iso" in the name. An example is the name given above for the compound of formula XIII. If 8-iso does not appear in the name, attachment of the carboxy-terminated chain in alpha configuration is to be assumed.
Novel compounds of this invention with epi configuration for the hydroxy at C-15 are so designated by using "15(R)" in the name. See, for example, the name given above for the formula-XII compound. Alternately, "15-beta" is used. See. R. S. Cahn, Journal of Chemical Education Vol. 41, page 116 (1964) for a discussion of S and R configurations. If "15(R)" or "15-beta" does not appear in the name, the natural configuration for the C-15 hydroxy, identified as the "S" configuration for PGE 1 , is to be assumed.
Some of the novel compounds of this invention differ structurally in other ways from the known prostanoic acid derivatives, having for example, more or fewer carbon atoms in either chain, and having one or more alkyl and/or fluoro substituents in the chains.
The following formulas represent the novel oxaphenylene compounds of this invention. ##SPC13##
Formulas XVI-XIX, and XXXII represent oxa-phenylene compounds of the PGE type. Formulas XX-XXIII, and XXXIII represent oxa-phenylene compounds of the PGF type. Formulas XXIV-XXVIII, and XXXIV represent oxa-phenylene compounds of the PGA type. Formulas XXVIII-XXXI, and XXXV represent oxa-phenylene compounds of the PGB type.
In formulas XVI to XXXV, the wavy line ˜ indicates attachment of the hydroxyl or the side chain to the cyclopentane ring in alpha or beta configuration;
G is (1) alkyl of 2 to 10 carbon atoms, inclusive, substituted with zero, one, 2, or 3 fluoro or (2) a monovalent moiety of the formula ##SPC14##
wherein C t H 2t represents a valence bond or alkylene of 1 to 10 carbon atoms, inclusive, substituted with zero, one, or 2 fluoro, with one to 7 carbon atoms, inclusive, between ##EQU1## and the ring, wherein T is alkyl of one to 4 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or --OR 6 , wherein R 6 is hydrogen or alkyl of one to 4 carbon atoms, inclusive, and wherein s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl; R 1 is hydrogen, alkyl of one to 12 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, phenyl substituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive, or ethyl substituted in the β-position with 3 chloro, 2 or 3 bromo, or 1, 2, or 3 iodo; Q is ##EQU2## wherein R 2 is hydrogen or alkyl of one to 4 carbon atoms, inclusive; R 3 and R 4 are hydrogen or methyl; and R 5 is alkyl of one to 4 carbon atoms, inclusive, substituted with zero, one, 2, or 3 fluoro.
Likewise, in formulas XVI to XXXV, C g H 2g represents a valence bond or alkylene of one to 4 carbon atoms, inclusive, with one or 2 chain carbon atoms between --CH 2 -- and the ring; C j H 2j represents a valence bond or alkylene of one or 2 carbon atoms with one chain carbon atom between the chain unsaturation and the ring; C n H 2n is alkylene of one to 4 carbon atoms, inclusive; C p H 2p represents a valence bond or alkylene of one to 4 carbon atoms, inclusive, with one or 2 chain carbon atoms between the ring and --O--, wherein C g H 2g and C p H 2p together represent zero to 8 carbon atoms, inclusive, with total chain lengths zero to 3 carbon atoms, inclusive, and wherein C j H 2j and C p H 2p together represent zero to 6 carbon atoms, inclusive, with total chain lengths zero to 3 carbon atoms, inclusive.
Regarding the meaning of C g H 2g , C j H 2j , and C p H 2p as defined above, the novel compounds of this invention include compounds wherein a carbon atom of the phenylene moiety is attached directly to the C-7 methylene or the C-5 =CR 4 -- in ortho, meta, or para orientation relative to the oxa-containing portion of the carboxyl chain. When C g H 2g represents alkylene, the chain of carbon atoms which connects the C-7 methylene to a carbon atom of phenylene will be one or 2 carbon atoms long. When C j H 2j represents alkylene, the chain of carbon atoms which connects =CR 4 -- to a carbon atom of phenylene will be one carbon atom long. C p H 2p represents a valence bond or alkylene of one to 6 carbon atoms, inclusive, with one or 2 carbon atoms between the ring and the --O--. Any or all of these alkylene chains are unsubstituted or substituted with alkyl carbons in the form of one or more alkyl groups within the total carbon content of each chain as specified above, i.e., a maximum of 4 carbon atoms of C g H 2g , 2 carbons for C j H 2j , and 4 carbons for C p H 2p . When C g H 2g or C j H 2j is alkylene, it is the same as or different than C p H 2p , 8 carbon atoms being the maximum total carbon content and 3 carbon atoms being the maximum total chain length for the combination of C g H 2g and C p H 2p , and 6 carbon atoms being the maximum total carbon content and 3 carbon atoms being the maximum total chain length for the combination of C j H 2j and C p H 2p . To illustrate these definitions, when C g H 2g is ethylene, C p H 2p is methylene, or one of them is a valence bond and the other is ethylene, but both are not ethylene. In this first illustration, where the total chain length of C g H 2g and C.sub. p H 2p is 3 carbon atoms, up to 5 carbon atoms are in the alkyl substituents.
Formulas XVI through XXXV include the separate isomers wherein Q is either ##EQU3## i.e. where the hydroxyl is in either alpha (natural) or beta configuration. Referring to the prostanoic acid atom numbering (formula I above), the point of attachment corresponds to C-15, and, herein, regardless of the variation in the C-1 to C-7 carboxy chain, these epimers are referred to as "C-15 epimers".
Formulas XX-XXIII, and XXXIII wherein the C-9 hydroxyl (following prostanoic acid atom numbering) is attached to the cyclopentane with a wavy line ˜ include both PGF.sub.α- and PGF.sub.β-type compounds.
Included in Formulas XVII, XXI, XXV, and XXIX, are both the cis and the trans compounds with respect to the C-5 to C-6 double bonds in the carboxyl-terminated side chain. In all of the compounds containing the C 13 to C 14 double bond, that double bond is in trans configuration, and the chain containing that moiety is attached to the cyclopentane ring in beta configuration in compounds encompassed by formulas XVI to XXXV.
The novel oxa-phenylene compounds of this invention include racemic compounds and both optically active enantiomeric forms thereof. As discussed hereinabove, two structural formulas are required to define accurately these racemic compounds. The formulas as drawn herein are intended to represent compounds with the same configuration as the naturally-occurring prostaglandins. However, for convenience in the charts herein only a single structural formula is used, for example in Chart D, to define not only the optically active form but also the racemic compounds which generally undergo the same reactions.
Formula XVI represents 3-oxa-4,5-inter-p-phenylene-PGE 1 (formula XI hereinabove) when C g H 2g is ethylene, C p H 2p is methylene, G is n-pentyl, Q is ##EQU4## R 1 is hydrogen, C g H 2g and C p H 2p are attached to the phenylene in para orientation, and the carboxyl-terminated side chain is attached to the cyclopentane ring in alpha configuration.
With regard to formulas XVI to XXXV, examples of alkyl of one to 4 carbon atoms, inclusive, are methyl, ethyl, propyl, butyl, and isomeric forms thereof. Examples of alkyl of 1 to 8 carbon atoms, inclusive, are those given above, and pentyl, hexyl, heptyl, octyl, and isomeric forms thereof. Examples of alkyl of one to 12 carbon atoms, inclusive, are those given above, and nonyl, decyl, undecyl, dodecyl, and isomeric forms thereof. Examples of cycloalkyl of 3 to 10 carbon atoms, inclusive, which includes alkyl-substituted cycloalkyl, are cyclopropyl, 2-methylcyclopropyl, 2,2-dimethylcyclopropyl, 2,3-diethylcyclopropyl, 2-butylcyclopropyl, cyclobutyl, 2-methylcyclobutyl, 3-propylcyclobutyl, 2,3,4-triethylcyclobutyl, cyclopentyl, 2,2-dimethylcyclopentyl, 3-pentylcyclopentyl, 3-tert-butylcyclopentyl, cyclohexyl, 4-tert-butylcyclohexyl, 3-isopropylcyclohexyl, 2,2-dimethylcyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl. Examples of aralkyl of 7 to 12 carbon atoms, inclusive, are benzyl, phenethyl, 1-phenylethyl, 2-phenylpropyl, 4-phenylbutyl, 3-phenylbutyl, 2-(1-naphthylethyl), and 1-(2-naphthylmethyl). Examples of phenyl substituted by one to 3 chloro or alkyl of one to 4 carbon atoms, inclusive, are p-chlorophenyl, m-chlorophenyl, o-chlorophenyl, 2,4-dichlorophenyl, 2,4,6-trichlorophenyl, p-tolyl, m-tolyl, o-tolyl, p-ethylphenyl, p-tert-butylphenyl, 2,5-dimethylphenyl, 4-chloro-2-methylphenyl, and 2,4-dichloro-3-methylphenyl.
Examples of alkyl of two to 10 carbon atoms, inclusive, substituted with one to 3 fluoro, are 2-fluoroethyl, 2-fluorobutyl, 3-fluorobutyl, 4-fluorobutyl, 5-fluoropentyl, 4-fluoro-4-methylpentyl, 3-fluoroisoheptyl, 8-fluorooctyl, 3,4-difluorobutyl, 4,4-difluoropentyl, 5,5-difluoropentyl, 5,5,5-trifluoropentyl, and 10,10,10-trifluorodecyl.
Examples of alkylene within the various scopes of C g H 2g , C j H 2j , C p H 2p , C n H 2n , and C t H 2t , as those are defined above, are methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, and heptamethylene, and those alkylene with one or more alkyl substituents on one or more carbon atoms, thereof, e.g., --CH(CH 3 )--, --C(CH 3 ) 2 --, --CH(CH 2 CH 3 )--, --CH 2 --CH(CH 3 )--, --CH(CH 3 )--CH(CH 3 )--, --CH 2 --C(CH 3 ) 2 --, --CH 2 --CH(CH 3 )--CH 2 --, --CH 2 --CH 2 --CH(CH 2 CH 2 CH 3 )--, --CH(CH 3 )--CH(CH 3 )--CH 2 --CH 2 --, --CH 2 --CH 2 --CH 2 --C(CH 3 ) 2 --CH 2 --, --CH 2 --CH 2 --CH 2 --CH 2 --CH(CH 3 )--, --CH 2 --CH 2 --CH 2 --CH 2 --CH 2 --C(CH 3 ) 2 --, --CH(CH 3 )--CH 2 --CH(CH 3 )--CH 2 --CH 2 --CH(CH 3 )--, and --CH 2 --CH 2 --CH 2 --CH 2 --CH 2 --CH 2 --C(CH 3 ) 2 --.
Examples of alkylene substituted with one or 2 fluoro and within the scope of C t H 2t , as defined above, are --CHF--CH 2 --, CHF--CHF--, --CH 2 --CH 2 --CF 2 --, --CH 2 --CHF--CH 2 --, --CH 2 --CH 2 --CF(CH 3 )--, --CH 2 --CH 2 --CH 2 --CF 2 --, and --CHF--CH 2 --CH 2 --CH 2 --CH 2 --CH 2 --CH 2 --.
Examples of ##SPC15##
as defined above are phenyl, p-tolyl, m-tolyl, o-tolyl, p-fluorophenyl, m-fluorophenyl, o-fluorophenyl, p-chlorophenyl, m-chlorophenyl, o-chlorophenyl, p-trifluoromethylphenyl, m-trifluoromethylphenyl, p-trifluoromethylphenyl, p-hydroxyphenyl, m-hydroxyphenyl, o-hydroxyphenyl, p-methoxyphenyl, m-methoxyphenyl, o-methoxyphenyl, p-tetrahydropyranyloxyphenyl, m-tetrahydropyranyloxyphenyl, o-tetrahydropyranyloxyphenyl, o-ethylphenyl, m-isopropylphenyl, p-tert-butylphenyl, p-butoxyphenyl, 3,4-dimethylphenyl, 2,4-diethylphenyl, 2,4,6-trimethylphenyl, 3,4,5-trimethylphenyl, 2,4-dichlorophenyl, 3,4-difluorophenyl, 2-chloro-4-methylphenyl, 2-fluoro-4-methoxyphenyl, 3,5-dimethyl-4-fluorophenyl, 2,6-dimethyl-4-hydroxyphenyl, and 2,4-di(trifluoromethyl)phenyl.
The novel formula XVI-XIX, and XXXII PGE-type oxa-phenylene compounds, the novel formula XX-XXIII, and XXXIII PGF.sub.α-type and PGF.sub.β-type oxa-phenylene compounds, the novel formula XXIV-XXVII, and XXXIV PGA-type oxa-phenylene compounds, and the novel formula XXVIII-XXXI, and XXXV PGB-type oxa-phenylene compounds each cause the biological responses described above for the PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB compounds, respectively, and each of these novel compounds is accordingly useful for the above-described corresponding purposes, and is used for those purposes in the same manner as described above.
The known PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB compounds uniformly cause multiple biological responses even at low doses. For example, PGE 1 and PGE 2 both cause vasodepression and smooth muscle stimulation at the same time they exert antilipolytic activity. Moreover, for many applications, these known prostaglandins have an inconveniently short duration of biological activity. In striking contrast, the novel prostaglandin analogs of formulas XVI to XXXV are substantially more specific with regard to potency in causing prostaglandin-like biological responses, and have a substantially longer duration of biological activity. Therefore, each of these novel prostaglandin analogs is useful in place of one of the corresponding above-mentioned known prostaglandins for at least one of the pharmacological purposes indicated above for the latter, and is surprisingly and unexpectedly more useful for that purpose because it has a different and narrower spectrum of biological activity than the known prostaglandin, and therefore is more specific in its activity and causes smaller and fewer undesired side effects than the known prostaglandin. Moreover, because of its prolonged activity, fewer and smaller doses of the novel prostaglandin analog can frequently be used to attain the desired result.
To obtain the optimum combination of biological response specificity, potency, and duration of activity, certain compounds within the scope of formulas XVI to XXXV are preferred. For example, in compounds of formulas XVI, XIX, XX, XXIII, XXIV, XXVII, XXVIII, and XXXI, it is preferred that the carboxyl-terminated side chain contain a total of 2 to 4 chain carbon atoms, inclusive, excluding the phenylene and --COOR 1 , and including the C-7 methylene. In other words, preferred compounds of these formulas are those wherein C g H 2g and C p H 2p together represent zero, one, or 2 chain carbon atoms. Especially preferred compounds of these formulas are those wherein C g H 2g and C p H 2p each represent a valence bond, and those wherein C g H 2g represents a valence bond and C p H 2p represents a single chain carbon atom, especially methylene.
In compounds of formulas XVII, XVIII, XXI, XXII, XXV, XXVI, XXIX, XXX, XXXII, XXXIII, XXXIV, and XXXV, it is preferred that the carboxyl-terminated side chain contain a total of 4 or 5 chain carbon atoms, excluding the phenylene and --COOR 1 , and including --CH 2 --CR 3 =CR 4 -- and --CH 2 --C.tbd.C--. In other words, preferred compounds of these formulas are those wherein C j H 2j and C p H 2p together represent zero or one chain carbon atoms. Included in these coumpounds are those wherein C j H 2j and C p H 2p each represent a valence bond, and those wherein C j H 2j represents a valence bond, and C p H 2p represents a single chain carbon atom, especially methylene.
As used herein, a chain carbon atom is part of the direct chain carbon atoms linking the C-7 methylene or =CR 4 -- to the phenylene, the phenylene to the oxa, and the oxa to --COOR 1 . Thus, the chain --CH(CH 3 )--C(CH 3 ) 2 -- contains 5 carbon atoms but only 2 chain atoms.
Another preference for the carboxy-terminated side chain in compounds of formulas XVI to XXXV is that the phenylene be a meta-phenylene.
Another preference for the compounds of formulas XVI to XXXV is that R 2 , R 3 , and R 4 are hydrogen or methyl. All of those R groups can be hydrogen, all can be methyl, or there can be any of the possible combinations of hydrogen and methyl.
Certain variations in the nature of G in the compounds of formulas XVI to XXXV are especially important. In the known PG 1 and PG 2 prostaglandins, e.g., PGE 1 , the portion of the molecule corresponding to G in formulas XVI to XXXI is n-pentyl. When G is unsubstituted alkyl or fluoro-substituted alkyl as defined above, there is a preference which results in compounds with optimum combinations of biological properties: namely that G is straight chain alkyl of 3 to 7 carbon atoms, inclusive, with or without a fluoro substituent at the 1-position , e.g., --CHF--(CH 2 ) a --CH 3 , wherein a is one, 2, 3, 4, or 5. Especially preferred among these are n-pentyl and 1-fluoropentyl.
When G is substituted alkyl, it is preferred that the 1-position be mono- or di-substituted with one or two alkyl groups containing from one to 4 carbon atoms, inclusive. Especially preferred are formula XVI-to-XXXV compounds wherein G is substituted at the 1-position with methyl and/or ethyl, e.g. --CH(CH 3 )--(CH 2 ) c --CH 3 , --CH(C 2 H 5 )--(CH 2 ) c --CH 3 , --C(CH 3 ) 2 --(CH 2 ) c --CH 3 , --C(C 2 H 5 ) 2 --(CH 2 ) c --CH 3 , or --C(CH 3 )(C 2 H 5 )--(CH 2 ) c --CH 3 , wherein c is 2, 3, or 4.
When G represents ##SPC16##
as defined above, it is preferred for compounds with optimum combination of biological properties that C t H 2t be a valence bond, i.e., t is zero, or alkylene of one to 4 carbon atoms, inclusive, i.e., --(CH 2 ) d -- wherein d is one, 2, 3, or 4, with or without a fluoro or alkyl substituent on the carbon adjacent to the hydroxy-substituted carbon (C-15 in PGE 1 ), e.g., --CHF--(CH 2 ) e --, --CH(CH 3 )--(CH 2 ) e --, or --C(CH 3 ) 2 --(CH 2 ) e --, wherein e is zero, one, 2, or 3. Further, it is preferred that the phenyl ring when present and substituted, be substituted at least at the para position.
In compounds of formulas XXXII to XXXV, it is preferred that C n H 2n be methylene and that R 5 be ethyl.
Another way of expressing the above preferences for G is that when G is alkyl or fluoro-substituted alkyl it be a group represented by ##EQU5## wherein a is 2, 3, 4, or 5, and wherein R 21 and R 22 are hydrogen, alkyl of one to 4 carbon atoms, inclusive, or fluoro, being the same or different, with the proviso that R 22 is fluoro only when R 21 is hydrogen or fluoro.
Furthermore, when G is ##SPC17##
it is preferred that when C t H 2t is alkylene or fluoro-substituted alkylene it be a group represented by ##EQU6## wherein e is zero, one, 2, or 3, and wherein R 21 and R 22 are as defined above.
Still another preference is that Q be ##EQU7## wherein R 2 is as defined hereinabove.
Another advantage of the novel compounds of this invention, especially the preferred compounds defined hereinabove, compared with the known prostaglandins, is that these novel compounds are administered effectively orally, sublingually, intravaginally, buccally, or rectally, in addition to usual intravenous, intramuscular, or subcutaneous injection or infusion methods indicated above for the uses of the known prostaglandins. These qualities are advantageous because they facilitate maintaining uniform levels of these compounds in the body with fewer, shorter, or smaller doses, and make possible self-administration by the patient.
The PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB type oxa-phenylene compounds encompassed by formulas XVI to XXXV including the special classes of compounds described above, are used for the purposes described above in the free acid form, in ester form, or in pharmacologically acceptable salt form. When the ester form is used, the ester is any of those within the above definition of R 1 . However it is preferred that the ester be alkyl of one to 12 carbon atoms, inclusive. Of those alkyl, methyl and ethyl are especially preferred for optimum absorption of the compound by the body or experimental animal system; and straight-chain octyl, nonyl,, decyl, undecyl, and dodecyl are especially preferred for prolonged activity in the body or experimental animal.
Pharmacologically acceptable salts of these formula XVI-to-XXXV compounds useful for the purposes described above are those with pharmacologically acceptable metal cations, ammonium, amine cations, or quaternary ammonium cations.
Especially preferred metal cations are those derived from the alkali metals, e.g., lithium, sodium and potassium, and from the alkaline earth metals, e.g., magnesium and calcium, although cationic forms of other metals, e.g., aluminum, zinc, and iron, are within the scope of this invention.
Pharmacologically acceptable amine cations are those derived from primary, secondary, or tertiary amines. Examples of suitable amines are methylamine, dimethylamine, trimethylamine, ethylamine, dibutylamine, triisopropylamine, N-methylhexylamine, decylamine, dodecylamine, allylamine, crotylamine, cyclopentylamine, dicyclohexylamine, benzylamine, dibenzylamine, α-phenylethylamine, β-phenylethylamine, ethylenediamine, diethylenetriamine, and like aliphatic, cycloaliphatic, and araliphatic amines containing up to and including about 18 carbon atoms, as well as heterocyclic amines, e.g., piperidine, morpholine, pyrrolidine, piperazine, and lower-alkyl derivatives thereof, e.g., 1-methylpiperidine, 4-ethylmorpholine, 1-isopropylpyrrolidine, 2-methylpyrrolidine, 1,4-dimethylpiperazine, 2-methylpiperidine, and the like, as well as amines containing water-solubilizing or hydrophilic groups, e.g., mono-, di-, and triethanolamine, ethyldiethanolamine, n-butylethanolamine, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, tris-(hydroxymethyl)aminomethane, N-phenylethanolamine, N-(p-tert-amylphenyl)-diethanolamine, galactamine, N-methylglucamine, N-methylglucosamine, ephedrine, phenylephrine, epinephrine, procaine, and the like.
Examples of suitable pharmacologically acceptable quaternary ammonium cations are tetramethylammonium, tetraethylammonium, benzyltrimethylammonium, phenyltriethylammonium, and the like.
The PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB type oxa-phenylene compounds encompassed by formulas XVI to XXXV including the special classes of compounds described above, are also used for the purposes described above in free hydroxy form or in the form wherein the hydroxy moieties are transformed to lower alkanoate moieties, e.g., --OH to --OCOCH 3 . Examples of lower alkanoate moieties are acetoxy, propionyloxy, butyryloxy, valeryloxy, hexanoyloxy, heptanoyloxy, octanoyloxy, and branched chain alkanoyloxy isomers of those moieties. Especially preferred among these alkanoates for the above described purposes are the acetoxy compounds. These free hydroxy and alkanoyloxy compounds are used as free acids, as esters, and in salt form all as described above.
As discussed above, the compounds of formulas XVI to XXXV are administered in various ways for various purposes; e.g., intravenously, intramuscularly, subcutaneously, orally, intravaginally, rectally, buccally, sublingually, topically, and in the form of sterile implants for prolonged action. For intravenous injection or infusion, sterile aqueous isotonic solutions are preferred. For that purpose, it is preferred because of increased water solubility that R 1 in the formula XVI-to-XXXV compound be hydrogen or a pharmacologically acceptable cation. For subcutaneous or intramuscular injection, sterile solutions or suspensions of the acid, salt, or ester form in aqueous or non-aqueous media are used. Tablets, capsules, and liquid preparations such as syrups, elixirs, and simple solutions, with the usual pharmaceutical carriers are used for oral sublingual administration. For rectal or vaginal administration, suppositories prepared as known in the art are used. For tissue implants, a sterile tablet or silicone rubber capsule or other object containing or impregnated with the substance is used.
The PGE, PGF.sub.α, PGF.sub.β, PGA and PGB type oxa-phenylene compounds encompassed by formulas XVI to XXXV are produced by the reactions and procedures described and exemplified hereinafter.
The various PGF.sub.α-type and PGF.sub.β-type oxa-phenylene compounds encompassed by formulas XX-XXIII and XXXIII are prepared by carbonyl reduction of the corresponding PGE type compounds encompassed by formulas XVI-XIX and XXXII. For example, carbonyl reduction of 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 gives a mixture of 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α and 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.β.
These ring carbonyl reductions are carried out by methods known in the art for ring carbonyl reductions of known prostanoic acid derivatives. See, for example, Bergstrom et al., Arkiv Kemi 19, 563 (1963), Acta Chem. Scand. 16, 969 (1962), and British Patent Specification No. 1,097,533. Any reducing agent is used which does not react with carbon-carbon double bonds or ester groups. Preferred reagents are lithium(tri-tert-butoxy)aluminum hydride, the metal borohydrides, especially sodium, potassium and zinc borohydrides, and metal trialkoxy borohydrides, e.g., sodium trimethoxyborohydride. The mixtures of alpha and beta hydroxy reduction products are separated into the individual alpha and beta isomers by methods known in the art for the separation of analogous pairs of known isomeric prostanoic acid derivatives. See, for example, Bergstrom et al., cited above, Granstrom et al., J. Biol. Chem. 240, 457 (1965), and Green et al., J. Lipid Research 5, 117 (1964). Especially preferred as separation methods are partition chromatographic procedures, both normal and reversed phase, preparative thin layer chromatography, and countercurrent distribution procedures.
The various PGA-type oxa-phenylene compounds encompassed by formulas XXIV-XXVII and XXXIV are prepared by acidic dehydration of the corresponding PGE type compounds encompassed by formulas XVI-XIX and XXXII. For example, acidic dehydration of 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 gives 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 .
These acidic dehydrations are carried out by methods known in the art for acidic dehydrations of known prostanoic acid derivatives. See, for example, Pike et al., Proc. Nobel Symposium II, Stockholm (1966), Interscience Publishers, New York, pp. 162-163 (1967); and British Patent Specification No. 1,097,533. Alkanoic acids of 2 to 6 carbon atoms, inclusive, especially acetic acid, are preferred acids for this acidic dehydration. Dilute aqueous solutions of mineral acids, e.g., hydrochloric acid, especially in the presence of a solubilizing diluent, e.g., tetrahydrofuran, are also useful as reagents for this acidic dehydration, although these reagents may cause partial hydrolysis of an ester reactant.
The various PGB-type oxa-phenylene compounds encompassed by formulas XXVIII-XXXI and XXXV are prepared by basic dehydration of the corresponding PGE type compounds encompassed by formulas XVI-XIX and XXXII, or by contacting the corresponding PGA type compounds encompassed by formulas XXIV-XXVII and XXXIV with base. For example, both 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 and 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 give 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGB 1 on treatment with base.
These basic dehydrations and double bond migrations are carried out by methods known in the art for similar reactions of known prostanoic acid derivatives. See, for example, Bergstrom et al., J. Biol. Chem. 238, 3555 (1963). The base is any whose aqueous solution has pH greater than 10. Preferred bases are the alkali metal hydroxides. A mixture of water and sufficient of a water-miscible alkanol to give a homogeneous reaction mixture is suitable as a reaction medium. The PGE-type or PGA-type compound is maintained in such a reaction medium until no further PGB-type compound is formed, as shown by the characteristic ultraviolet light absorption near 278 mμ for the PGB type compound.
The various transformations of PGE-type oxa-phenylene compounds of formulas XVI-XIX to the corresponding PGF.sub.α, PGF.sub.β, PGA and PGB type oxa-phenylene compounds are shown in Chart A, wherein G, Q, R 1 , and ˜ are as defined above, wherein E' is --CH 2 CHR 9 -- or trans--CH=CR 9 --, wherein R 26 and R 9 are hydrogen or alkyl of one to 4 carbon atoms, inclusive, and wherein J' is ##SPC18##
wherein V is C g H 2g , cis or trans ##EQU8## or --C.tbd.C--C j H 2j wherein C g H 2g , C j H 2j , C p H 2p , R 3 , and R 4 are as defined above, and wherein C q H 2q represents alkylene of one to 6 carbon atoms, inclusive, with one, 2, or 3 carbon atoms between --O-- and --COOR 1 .
The various 13,14-dihydro-PGE 1 , -PGF 1 , -PGA 1 , and -PGB 1 , type oxa-phenylene compounds encompassed by formulas XIX, XXIII, XXVII, and XXXI are prepared by carbon-carbon double bond reduction of the corresponding PGE, PGF, PGA, and PGB type compound containing a trans double bond in the hydroxy-containing side chain. A cis or trans double bond or a triple bond can also be present in the carboxy-terminated side chain of the unsaturated reactant, and will be reduced at the same time to --CH 2 CH 2 --. For example, 13,14-dihydro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 is produced by reduction of 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 , 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 2 , or 5,6-dehydro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 2 .
These reductions are carried out by reacting with the unsaturated PGE, PGF.sub.α, PGF.sub.β, PGA, or PGB type oxa-phenylene compound with diimide, following the general procedure described by van Tamelen et al., J. Am. Chem. Soc. 83, 3725 (1961). ##SPC19##
See also Fieser et al., "Topics in Organic Chemistry," Reinhold Publishing Corp., New York, pp. 432-434 (1963) and references cited therein. The unsaturated acid or ester reactant is mixed with a salt azodiformic acid preferably an alkali metal salt such as disodium or dipotassium salt, in the presence of an inert diluent, preferably a lower alkanol such as methanol or ethanol, and preferably in the absence of substantial amounts of water. At least one molecular equivalent of the azodiformic acid salt is used for each multiple bond equivalent of the unsaturated reactant. The resulting suspension is then stirred, preferably with exclusion of oxygen, and the mixture is made acid, advantageously with a carboxylic acid such as acetic acid. When a reactant wherein R 1 is hydrogen is used, the carboxylic acid reactant also serves to acidify an equivalent amount of the azodiformic acid salt. A reaction temperature in the range of about 10° to about 40° C. is usually suitable. Within that temperature range, the reaction is usually complete within less than 24 hours. The desired dihydro production is then isolated by conventional methods, for example, evaporation of the diluent, followed by separation from inorganic materials by solvent extraction.
In the case of the oxa-phenylene unsaturated PGE, PGF.sub.α, and PGF.sub.β type reactants, the reductions to the corresponding dihydro-PGE 1 , dihydro-PGF 1 .sub.α, and dihydro-PGF 1 .sub.α type oxa-phenylene compounds are also carried out by catalytic hydrogenation. For that purpose, palladium catalysts, especially on a carbon carrier, are preferred. It is also preferred that the hydrogenation be carried out in the presence of an inert liquid diluent, for example, methanol, ethanol, dioxane, ethyl acetate, and the like. Hydrogenation pressures ranging from about atmospheric to about 50 p.s.i., and hydrogenation temperatures ranging from about 10° to about 100° C. are preferred. The resulting dihydro product is isolated from the hydrogenation reaction mixture by conventional methods, for example, removal of the catalyst by filtration or centrifugation, followed by evaporation of the solvent.
Diimide reductions and catalytic hydrogenations to produce the various novel formula XIX, XXIII, XXVII, and XXXI 13,14-dihydro compounds of this invention from the corresponding PGE, PGF, PGA and PGB type oxa-phenylene compounds of the PG 1 , PG 2 , trans-5,6-dehydro-PG 1 , and 5,6-dehydro-PG 2 series are shown in Chart B. G, J', Q, R 1 , R 9 , R 26 , and ˜ are as defined above, and L' is ##SPC20##
wherein C g H 2g , C p H 2p , and C q H 2q are as defined above.
The oxa-phenylene compounds of the PGE 2 , PGF 2 , PGA 2 , and PGB 2 type wherein the carbon-carbon double bond in the carboxy-terminated side chain is in cis configuration are prepared by reduction of the corresponding acetylenic oxa-phenylene compounds, i.e., those with a carbon-carbon triple bond in place of said carbon-carbon double bond. For that purpose, there are used any of the known reducing agents which reduce an acetylenic linkage to a cis-ethylenic linkage. Especially preferred for that purpose are diimide, or hydrogen and a catalyst, for example, palladium (5%) on barium sulfate, especially in the presence of pyridine. See Fieser et al., "Reagents for Organic Synthesis," pp. 566-567, John Wiley and Sons, Inc., New York, N.Y. (1967). ##SPC21##
These reductions are shown in Chart C, wherein G, Q, R 1 , R 9 , R 26 , and ˜ are as defined above, and M' is ##SPC22##
wherein C j H 2j , C p H 2p , and C q H 2q are defined above. These oxa-phenylene cis compounds of the PGE 2 , PGF 2 .sub.α, PGF 2 .sub.β, PGA 2 , and PGB 2 type are also prepared as described hereinafter.
The oxa-phenylene PGE-type compounds of formulas XVI-XIX except wherein R 1 is hydrogen, and the oxa-phenylene PGA-type compounds of formulas XXIV-XXVII except wherein R 1 is hydrogen, are prepared by the series of reactions shown in Chart D, wherein G, J', R 2 , R 9 , and R 26 are as defined above; G' is the same as G except that T is replaced by T', wherein T' is the same as T above except that R 9 is not hydrogen; R 10 is the same as the above definition of R 1 except that R 10 does not include hydrogen; R 11 and R 12 are alkyl of one to 4 carbon atoms, inclusive; R 13 is alkyl of one to 5 carbon atoms, inclusive; and ˜ indicates attachment of --CHR 26 --J'--COOR 10 to the cyclopentane ring in alpha or beta configuration, and attachment of the moiety to the cyclopropane ring in exo or endo configuration.
The oxa-phenylene PGE 1 -type compounds of formula XVI, the oxa-phenylene 5,6-dehydro-PGE 2 type compounds of formula XVIII, the oxa-phenylene PGA 1 -type compounds of the formula XXIV and the oxa-phenylene 5,6-dehydro-PGA 2 type compounds of formula XXVI are also prepared by the series of reactions shown in Chart E, wherein G, G', R 2 , R 9 , R 10 , R 13 , and R 26 are as defined above; Z' is L' or --C.tbd.C--M'-- wherein L' and M' are as defined above; and ˜ indicates attachment of --CHR 26 --Z'--COOR 10 to the cyclopentane ring in alpha or beta configuration, and attachment of the moiety to the cyclopropane ##SPC23## ##SPC24## ##SPC25##
cyclopropane ring in ex or endo configuration.
It should be observed regarding the series of reactions shown in Charts D and E, that the reactions starting with glycol XXXVIII in Chart D are similar to the reactions starting with glycol XLV in Chart E. The only differences here are the definitions of the divalent moieties J' (Chart D) and Z' (Chart E). J' includes saturated, cis and trans ethylenic, and acetylenic divalent moieties. Z' is limited to the saturated and acetylenic divalent moieties encompassed by J'. In other words, final oxa-phenylene PGE-type compounds of formula XL (Chart D) encompass compounds of formulas XVI to XVIII. Final oxa-phenylene PGA-type compounds of formula XLI (Chart D) encompass compounds of formulas XXIV to XXVI. On the other hand, final oxa-phenylene PGE-type compounds of formula XLVII (Chart E) encompass only compounds of formulas XVI and XVIII, and final oxa-phenylene PGA-type compounds of formula XLVIII (Chart E) encompass only compounds of formula XXIV and XXVI.
As will subsequently appear, an acetylenic intermediate of formulas XXXVII, XXXVIII, or XLV is transformed by step-wise reduction to the corresponding cis or trans ethylenic intermediates of formulas XXXVII or XXXVIII; and an acetylenic intermediate of formulas XXXVII, XXXVIII, or XLV or a cis or trans ethylenic intermediate of formulas XXXVII or XXXVIII is transformed by reduction to the corresponding saturated intermediate of formulas XXVII, XXXVIII, or XLV.
The initial bicyclo-ketone reactant of formula XLIII in Chart E is also used as an initial reactant to produce the initial bicyclo-ketone cyclic ketal reactant of formula XXXVI in Chart D. The following reactions will produce cyclic ketal XXXVI, wherein THP is tetrahydropyranol, and φis phenyl: ##SPC26##
The bicyclo-ketone reactant of formula XLIII exists in four isomeric forms, exo and endo with respect to the attachment of the --CR 9 =CR 2 G moiety, and cis and trans with respect to the double bond in that same moiety. Each of those isomers separately or various mixtures thereof are used as reactants according to this invention to produce substantially the same final oxa-phenylene PGE or PGA type product mixture.
The process for preparing either the exo or endo configuration of the formula-XLIII bicyclo-ketone is known to the art. See. U.S. Pat. No. 3,776,940 and Belgian Pat. No. 702,477, Derwent Farmdoc No. 30,905.
See West Germany Offenlegungsschrift No. 1,937,912; reprinted in Farmdoc Complete Specifications, Book No. 14, No. 6869 R, Week R 5 , Mar. 18, 1970.
In said U.S. Pat. No. 3,776,940 a reaction sequence capable of forming exo ketone XLIII is as follows: The hydroxy of 3-cyclopentenol is protected, for example, with a tetrahydropyranyl group. Then a diazoacetic acid ester is added to the double bond to give an exo-endo mixture of a bicyclo[3.1.0]hexane substituted at 3 with the protected hydroxy and at 6 with an esterified carboxyl. The exo-endo mixture is treated with a base to isomerize the endo isomer in the mixture to more of the exo isomer. Next, the carboxylate ester group at 6 is transformed to an aldehyde group or ketone group, ##EQU9## wherein R 9 is as defined above. Then, said aldehyde group or said keto group is transformed by the Wittig reaction, in this case to a moiety of the formula --CR 9 =CR 2 G which is in exo configuration relative to the bicyclo ring structure. Next, the protective group is removed to regenerate the 3-hydroxy which is then oxidized, for example, by the Jones reagent, i.e., chromic acid (see J. Chem. Soc. 39 (1946)), to give said exo ketone XLIII.
Separation of the cis-exo and trans-exo isomers of XLIII is described in said U.S. Pat. No. 3,776,940. However, as mentioned above, that separation is usually not necessary since the cis-trans mixture is useful as a reactant in the next process step.
The process described in said U.S. Pat. No. 3,776,940 for producing the exo form of bicyclo-ketone XLIII uses, as an intermediate, the exo form of a bicyclo [3.1.0]-hexane substituted at 3 with a protected hydroxy, e.g., tetrahydropyranyloxy, and at 6 with an esterified carboxyl. When the corresponding endo compound is substituted for that exo intermediate, the process in said Offenlegungsschrift No. 1,937,912 leads to the endo form of bicyclo-ketone XLIII. That end compound to be used has the formula: ##SPC27##
Compound LII is prepared by reacting endo-bicyclo[3.1.0]-hex-2-ene-6-carboxylic acid methyl ester with diborane in a mixture of tetrahydrofuran and diethyl ether, a reaction generally known in the art, to give endo-bicyclo[3.1.0]-hexane-3-ol-6-carboxylic acid methyl ester which is then reacted with dihydropyran in the presence of a catalytic amount of POCl 3 to give the desired compound. This is then used as described in said German Offenlegungsschrift No. 1,937,912 to produce the endo form of bicyclo-ketone XLIII.
As for exo XLIII, the above process produces a mixture of endo-cis and endo-trans compounds. These are separated as described for the separation of exo-cis and exo-trans XLIII, but this separation is usually not necessary since, as mentioned above, the cis-trans mixture is useful as a reactant in the next process step.
In the processes of said U.S. patent and said Offenlegungsschrift, certain organic halides, e.g., chlorides and bromides, are necessary to prepare the Wittig reagents used to generate the generic moiety, --CR 9 =CR 2 G of bicyclo-ketone XLIII. These organic chlorides and bromides ##EQU10## are known in the art or can be prepared by methods known in the art.
To illustrate the availability of these organic chlorides consider first the above-described oxa-phenylene PGE-type compounds of formulas XVI to XIX wherein R 2 is hydrogen and G is either (1) alkyl of one to 10 carbon atoms, inclusive, substituted with zero, one, 2, or 3 fluoro or ##SPC28##
wherein C t H 2t represents a valence bond or alkylene of one to 10 carbon atoms, inclusive, substituted with zero, one, or 2fluoro, with one to 7 carbon atoms, inclusive, between ##EQU11## and the ring, wherein T is alkyl of one to 4 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or --OR 6 , wherein R 6 is hydrogen or alkyl of one to 4 carbon atoms, inclusive, and s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl.
For those products wherein G is alkyl of two to 10 carbon atoms, substituted with 0-3 fluoro atoms, there are available the monohalo hydrocarbons, e.g., bromo-(or chloro-) -ethane, -propane, -pentane, -octane, and -decane; and the monohalofluorohydrocarbons, e.g., CH 2 FCH 2 Br, CHF 2 CH 2 Cl, CF 3 CH 2 Br, F(CH 2 ) 3 Br, CH 3 CF 2 CH 2 Cl, CF 3 (CH 2 ) 2 Br, F(CH 2 ) 4 Cl, CH 3 CF 2 CH 2 CH 2 Cl, C 4 H 9 CFHCH 2 Br, CF 3 (CH 2 ) 3 Cl, CF 3 (CH 2 ) 2 BrCH 3 , CH 2 F(CH 2 ) 4 Cl, C 2 H 5 CF 2 (CH 2 ) 2 Cl, CF 3 (CH 2 ) 4 Cl, CH 3 (CH 2 ) 4 CF 2 (CH 2 ) 2 CH 2 Cl, and CH 3 (CH 2 ) 3 CF 2 (CH 2 ) 3 CH 2 Cl, as described in "Aliphatic Fluorine Compounds," A. M. Lovelace et al., Am. Chem. Soc. Monograph Series, 1958, Reinhold Publ. Corp. Those halides not available are prepared by methods known in the art by reacting the corresponding primery alcohol G--CH 2 OH with PCl 3 PBr 3 , or any of the other halogenating agents useful for this purpose. Available alcohols include CH 2 CH(CF 3 )CH 2 OH, (CH 3 ) 2 CHCH 2 CH 2 OH, (CH 3 ) 3 CCH 2 OH, CF 3 CH(CH 3 )CH 2 CH 2 OH, for example. For those halides of the formula G--CH 2 --Hal wherein Hal is chloro or bromo, G is R 27 --(CH 2 ) h --, h being one, 2, 3, or 4, and R 27 being isobutyl, tert-butyl, 3,3-difluorobutyl, 4,4-difluorobutyl, or 4,4,4-trifluorobutyl, the intermediate alcohols are prepared as follows.
In the case of R 27 being isobutyl or tert-butyl, known alcohols are converted to bromides, thence to nitriles with sodium cyanide, thence to the corresponding carboxylic acids by hydrolysis, and thence to the corresponding primary alcohols by reduction, e.g., with lithium aluminum hydride, thus extending the carbon chain one carbon atom at a time until all primary alcohols are prepared.
In the case of R 27 being 3,3-difluorobutyl, the necessary alcohols are prepared from keto carboxylic acids of the formula, CH 3 --CO--(CH 2 ) r --COOH, wherein r is 2, 3, 4, 5, or 6. All of those acids are known. The methyl esters are prepared and reacted with sulfur tetrafluoride to produce the corresponding CH 3 --CF 2 --(CH 2 ) r --COOCH 3 compounds, which are then reduced with lithium aluminum hydride to CH 3 --CF 2 --(CH 2 ) r --CH 2 OH. These alcohols are then transformed to the bromide or chloride by reaction with PBr 3 or PCl 3 .
In the case of R 27 being 4,4-difluorobutyl, the initial reactants are the known dicarboxylic acids, HOOC--(CH 2 ) f --COOH, wherein f is 3, 4, 5, 6, or 7. These dicarboxylic acids are esterified to CH 3 OOC--(CH 2 ) f --COOCH 3 and then half-saponified, for example with barium hydroxide, to give HOOC--(CH 2 ) f --COOCH 3 . The free carboxyl group is transformed first to the acid chloride with thionyl chloride and then to an aldehyde by the Rosenmund reduction. Reaction of the aldehyde with sulfur tetrafluoride then gives CHF 2 --(CH 2 ) f --COOCH 3 which by successive treatment with lithium aluminum hydride and PBr 3 or PCl 3 gives the necessary bromides or chlorides, CHF 2 --(CH 2 ) f --CH 2 Br or CHF 2 --(CH 2 ) f --CH 2 Cl.
In the case of R 27 being 4,4,4-trifluorobutyl, aldehydes of the formula CH 3 OOC--(CH 2 ) f --CHO are prepared as described above. Reduction of the aldehyde with sodium borohydride gives the alcohol CH 3 OOC--(CH 2 ) f --CH 2 OH. Reaction with PBr 3 or PCl 3 then gives CH 3 OOC--(CH 2 ) f -CH 2 --Hal. Saponification of that ester gives the carboxylic acid which by reaction with sulfur tetrafluoride gives the necessary CF 3 --(CH 2 ) f --CH 2 Br or CF 3 --(CH 2 ) f --CH 2 --Cl.
For the above reactions of SF 4 , see U.S. Pat. No. 3,211,723 and J. Org. Chem. 27, 3164 (1962).
For those products wherein R 2 is hydrogen and G is ##SPC29##
the halides necessary to prepare those compounds, if not readily available, are advantageously prepared by reacting the corresponding primary alcohol, ##SPC30##
with PCl 3 , PBr 3 , HBr, or any of the other halogenating agents known in the art to be useful for this purpose. Some of the readily available halides are shown in Table I wherein s, T, and t of the formula for the intermediate halides are as defined above, and Hal is chloro, bromo, or iodo. Thus, compound No. 1 of Table I is represented by the formula wherein s and t are zero, and Hal is chloro, i.e. ##SPC31##
namely α-chlorotoluene or benzyl chloride; compound No. 8 of Table I is represented by the formula wherein s is zero, t is 2, and Hal is bromo, i.e. ##SPC32##
namely 1-bromo-3-phenylpropane or 3-bromopropylbenzene; and compound No. 63 of Table I represented by the formula wherein s is 3, T is methyl in the 2-, 4- and 5-positions with respect to the C t H 2t substitution, t is 2, and Hal is bromo, i.e., ##SPC33##
namely 1 -(3-bromopropyl)-2,4,5-trimethylbenzene.
TABLE I______________________________________Intermediate Halidesrepresented by the formulaNo. s T t Hal______________________________________1 0 -- 0 Cl2 0 -- 0 Br3 0 -- 0 l4 0 -- 1 Cl5 0 -- 1 Br6 0 -- 1 l7 0 -- 2 Cl8 0 -- 2 Br9 0 -- 2 l10 0 -- 3 Cl11 0 -- 3* Cl12 0 -- 3 Br13 0 -- 4 Cl14 1 2--CH.sub.3 0 Cl15 1 2--C.sub.2 H.sub.5 0 Cl16 1 4--C.sub.2 H.sub.5 0 Cl17 1 2--CF.sub.3 0 Cl18 1 4--OCH.sub.3 0 Cl19 1 3--CH.sub.3 0 Br20 1 4--CH.sub.3 0 Br21 1 4--C.sub.5 H.sub.11 0 Br22 1 4--Cl 0 Br23 1 2--CF.sub.3 0 Br24 1 3--CF.sub.3 0 Br25 1 4--CH.sub.3 0 l26 1 4--F 1 Cl27 1 3--Cl 1 Br28 1 4--Cl 1 Br29 1 4--F 1 Br30 1 2--Cl 2 Br31 1 3--Cl 2 Br32 1 4--Cl 2 Br33 1 4--F 3* Br34 1 2--Cl 4 Br35 1 2--CH.sub.3 0 Cl 4--CH.sub.336 2 2--CH.sub.3 0 Cl 5--CH.sub.337 2 2--CH.sub.3 0 Cl 6--CH.sub.338 2 3--CH.sub.2 0 Cl 4--CH.sub.339 2 2--CH.sub.3 0 Cl 4--Cl40 2 2--CH.sub.3 0 Br 5--CH.sub.341 2 2--CH.sub.3 0 Br 6--CH.sub.342 2 3--CH.sub.3 0 Br 5--t--butyl43 2 3--CH.sub.3 0 Br 4--Cl44 2 2--CH.sub.3 0 Br 3--Br45 2 3--OCH.sub.3 0 Cl 4--OCH.sub.346 2 3--OCH.sub.3 0 Cl 5--OCH.sub.347 2 3--OCH.sub.3 0 Br 5--OCH.sub.348 2 2--CH.sub.3 1 Cl 4--CH.sub.349 2 2--CH.sub.3 1 Br 4--CH.sub.350 2 3--CH.sub.3 1 Br 4--CH.sub.351 2 3--OCH.sub.3 1 Br 4--OCH.sub.352 2 3--OCH.sub.3 1 Br 5--OCH.sub.353 2 3--OCH.sub.3 1 l 4--OCH.sub.354 2 3--OCH.sub.3 2 Br 4--OCH.sub.355 2 3--OCH.sub.3 2 Br 5--OCH.sub.356 2 3--OCH.sub.3 4 Br 5--OCH.sub.357 3 2--CH.sub.3 0 Cl 4--CH.sub.3 5--CH.sub.358 3 2--CH.sub.3 0 Cl 4--CH.sub.3 6--CH.sub.359 3 4--CH.sub.3 0 Cl 2--OCH.sub.3 5--OCH.sub.360 3 2--CH.sub.3 0 Br 3--CH.sub.3 6--CH.sub.361 3 2--CH.sub.3 0 Br 4--CH.sub.3 6--CH.sub.362 3 2--CH.sub.3 0 Br 3--OCH.sub.3 6--OCH.sub.363 3 2--CH.sub.3 2 Br 4--CH.sub.3 5--CH.sub.3______________________________________--CH--*-branched|Et
Next, considering the intermediate halides for producing oxa-phenylene PGE-type compounds of formulas XIII to XVI wherein R 2 is alkyl of one to 4 carbon atoms, inclusive (A), and G is either of the two types (1) or (2) above, these organic chlorides and bromides, ##EQU12## are known to the art or can be prepared by methods known in the art.
For type A-(1) above, i.e. wherein R 2 is alkyl and G is alkyl of one to 10 carbon atoms and 0-3 fluoro atoms, there are available such monohalofluorohydrocarbons as CHF 2 CHClCH 3 , CF 3 CHBrCH 3 , CF 3 CH 2 CHBrCH 3 , CH 3 CF 2 CHClCH 3 , CF 3 CHClC 2 H 5 , and C 2 H 5 CF 2 CHClCH 3 , for example. Those not readily available are prepared from the corresponding secondary alcohol ##EQU13## wherein R 2 is as defined above, with PCl 3 , PBr 3 , or any of the other halogenating agents known in the art to be useful for this purpose. Such alcohols include, for example, CH 2 FCH(OH)CH 2 F, CF 3 (CH 2 ) 2 CH(OH)CH 3 , CF 3 CH(OH)(CH 2 )CH 3 , CF 3 CH(OH)(CH 2 ) 3 CH 3 , CF 3 CH(OH)C(CH 3 ) 3 , and CF 3 CH(OH)(CH 2 ) 5 CH 3 . For those halides of the formula G--CHR 2 --Hal, wherein G is R 27 --(CH 2 ) h --, using the definitions of Hal, h, R 2 , and R 27 above, the intermediate alcohols are prepared as follows.
In the case of R 27 being isobutyl or tert-butyl, lower molecular weight primary alcohols are transformed to the corresponding longer-chain carboxylic acids and thence to the corresponding secondary alcohols by preparing the intermediate ketones, ##EQU14## by known procedures, for example G--COCl + (R 2 ) 2 Cd, thereafter reducing the ketone to the secondary alcohol with sodium borohydride.
In the case of R 27 being 3,3-difluorobutyl, the procedure described above is applicable to converting CH 3 --CF 2 --(CH 2 ) 2 --COOCH 3 described above to ##EQU15## These alcohols are then transformed to the bromide or chloride by reaction with PBr 3 or PCl 3 .
In the case of R 27 being 4,4-difluorobutyl, the corresponding secondary alcohols are prepared as described above, using intermediates prepared for the primary alcohols of this type above.
In the case of R 27 being 4,4,4-trifluorobutyl, corresponding secondary alcohols are prepared by transforming CH 3 OOC--(CH 2 ) f --CHO to CH 3 OOC--(CH 2 ) f --C(R 2 )O by known methods and then proceeding with that ketone as described above for the corresponding aldehyde.
For type A-(2) halides, i.e. R 2 is alkyl and G is ##SPC34##
some of the readily available halides are shown in Table II. Thus, compound No. 1 of Table II is represented by the formula wherein s=0, R 2 =methyl, t=0, and Hal=Cl, i.e. ##SPC35##
namely (1-chloroethyl)benzene; and compound No. 13 of Table II is represented by the formula wherein s=2, T=methyl, R 2 =methyl, t=1, and Hal=Br, i.e. ##SPC36##
namely 4-(2-bromopropyl)-o-xylene or 1-(2-bromopropyl)3-methyl-4-methylbenzene.
TABLE II______________________________________Intermediate Halidesrepresented by the FormulaHal--CH--C.sub.t H.sub.2t --|R.sub.2No. s T R.sub.2 t Hal______________________________________1 0 -- CH.sub.3 0 Cl2 0 -- C.sub.2 H.sub.5 0 Cl3 0 -- C.sub.2 H.sub.5 0 Br4 0 -- CH.sub.3 0 l5 0 -- CH.sub.3 1 Cl6 0 -- n--C.sub.3 H.sub.7 1 Cl7 0 -- CH.sub.3 1 Br8 0 -- C.sub.2 H.sub.5 2 Cl9 1 4--C.sub.2 H.sub.5 CH.sub.3 0 Cl10 1 4--F CH.sub.3 0 Cl11 1 4--Cl C.sub.2 H.sub.5 0 Br12 1 4--F C.sub.2 H.sub.5 0 Br13 2 3--CH.sub.3 CH.sub.3 1 Br 4--CH.sub.314 2 3--OCH.sub.3 CH.sub.3 1 Br 4--OCH.sub.315 2 2--OCH.sub.3 CH.sub.3 1 Br 6--OCH.sub.3______________________________________
Other intermediate halides of the general formula ##SPC37##
may be obtained from the secondary alcohols as discussed above. The secondary alcohols, wherein R 2 is alkyl, are prepared by transforming the --COOH of the corresponding carboxylic acid, ##SPC38##
to a ketone by known procedures, e.g. by way of acyl chloride and a dialkylcadmium. Reduction of the ketone with sodium borohydride then yields the secondary alcohol, ##SPC39##
Hydroxyl groups on the aromatic ring are suitably protected during these reactions by first forming the corresponding tetrahydropyranyl ethers with dihydropyran; the hydroxyl groups are restored by mild acid hydrolysis as is well known in the art.
In the case of C t H 2t substituted with one or 2 fluoro atoms, there are a number of routes of the intermediate halides. The corresponding alcohols, for example β-fluorophenethyl alcohol, β-fluoro-α-methyl-phenethyl alcohol, β-fluoro-α,β-dimethyl-phenethyl alcohol and the like, are reacted with PCl 3 , PBr 3 or HBr to form the halide. Alternatively, the carboxylic acid having one less carbon atom in the chain than the desired intermediate halide, i.e. ##SPC40##
where g = t-1, is converted by a series of known methods to the 2,2-difluorohalide. Thus, the free carboxyl group is transformed first to the acid chloride with thionyl chloride and thence by way of the nitrile to the α-keto-acid. The carboxyl group is reduced to the alcohol with diborane and then converted to the α-keto halide. Finally, by reaction of the keto group with sulfur tetrafluoride, there is obtained ##SPC41##
As mentioned above, formula XVI-to-XXXI compounds with an alpha-fluoro substituent in a straight chain 3-to-7-carbon G, i.e., G being --CHF--(CH 2 ) a --CH 3 wherein a is one, 2, 3, 4, or 5, represent embodiments among the novel oxa-phenylene compounds of this invention. Among those, for example, is 3-oxa-16-fluoro-3-7-inter-m-phenylene-4,5,6-trinor-PGE 1 . The formula-XLIII bicyclo-ketones necessary to produce those mono-fluoro compounds are advantageously prepared by reacting either of the above-mentioned bicyclo-aldehydes, exo or endo, with a Wittig reagent prepared from CH 3 --CH 2 ) a-- CO--CH 2 --Br and triphenylphospine. The aldehyde group is thereby transformed to ##EQU16## The resulting unsaturated ketone is reduced to the corresponding ##EQU17## compound. Then --OH in that group is replaced with fluoro by known methods, for example, directly by reaction with 2-chloro-1,1,2-trifluorotriethylamine or indirectly, for example, by transforming the hydroxy to tosyloxy or mesyloxy, and reacting the resulting compound with anhydrous potassium fluoride in diethylene glycol. Similarly, the oxa-phenylene PG-type compounds wherein G is ##SPC42##
having an alpha-fluoro substituent on the carbon adjacent to the hydroxy-substituted carbon (C-15 in PGE 1 ) represent preferred embodiments of this invention. In preparing the formula-XLIII bicyclo-ketone intermediates, there is used a Wittig reagent prepared from ##SPC43##
and triphenylphosphine. Following the steps above, the resulting unsaturated ketone containing the moiety ##SPC44##
is reduced to the corresponding secondary alcohol. The --OH in that group is replaced by fluoro by known methods.
Another preference mentioned above is that the 1-position of G in the formula XVI-to-XXXI compounds be mono- or di-substituted with alkyl of one to 4 carbon atoms, particularly methyl or ethyl. In the steps of the synthesis shown in Charts D and E, G is then G'" --CR 21 R 22 -- wherein R 21 and R 22 are methyl or ethyl and G'" is preferably alkyl of 2 to 6 carbon atoms or ##SPC45##
wherein k is zero, one, 2, or 3. Thus in preparing the formula-XLIII intermediate olefin, a Wittig reagent is prepared from a halo compound of the general formula G'" --CR 21 R 22 --CR 2 H--Hal wherein Hal is chloro or bromo. These compounds are known in the art or can be prepared by methods known in the art, including those methods described above.
For example, when G'" is CH 3 (CH 2 ) 3 --, R 2 and R 21 are hydrogen, and R 22 is methyl, there is employed 1-bromo(or -chloro)-2-methylhexane. If the halo compound is not available, the corresponding carboxylic acid is transformed to the alcohol and thence to the halide. Thus, 2,2-diethylvaleric acid yields 1-bromo-2,2-diethylpentane, wherein G'" is CH 3 (CH 2 ) 2 --, R 2 is hydrogen, and R 21 and R 22 are ethyl.
2-Ethylhexanoic acid yields 3-chloromethylheptane, wherein G'" is CH 3 (CH 2 ) 3 --, R 2 and R 21 are hydrogen, and R 22 is ethyl. 2-Ethyl-2-methylhexanoic acid yields 3-bromo-methyl-3-methylheptane, wherein G'" is CH 3 (CH 2 ) 3 --, R 2 is hydrogen, R 21 is methyl, and R 22 is ethyl. 2-Phenylpropionic acid yields 1-bromo-2-phenylpropane, wherein G'" is phenyl, R 2 and R 21 are hydrogen, and R 22 is methyl. 2-Methyl-2-phenylbutyric acid yields 1-bromo-2-methyl-2-phenylbutane, wherein G'" is phenyl, R 2 is hydrogen, R 21 is methyl, and R 22 is ethyl. 2-Methyl-4-(2,4,5-trimethoxyphenyl)butyric acid yields 1-chloro-2-methyl-4-(2,4,5-trimethoxyphenyl)butane, wherein G'" is (2,4,5-trimethoxyphenyl)ethyl, R 2 and R 21 are hydrogen, and R 22 is methyl.
Mono-alkyl substituted alkanoic acids useful for preparing the above halo intermediates are prepared by alkylation of an α-keto acid, G'" --CO--COOH, e.g. ##SPC46##
(prepared via the acid chloride and thence the nitrile) by means of a Grignard reagent, R 22 MgHal for example.
The transformation of bicyclo-ketone-olefin XLIII to glycol LI is carried out by reacting olefin XLIII with a hydroxylation reagent. Hydroxylation reagents and procedures for this purpose are known in the art. See, for example, Gunstone, Advances in Organic Chemistry, Vol. I, pp. 103-147, Interscience Publishers, New York, N.Y. (1960). Especially useful hydroxylation reagents for this purpose are osmium tetroxide and performic acid (formic acid plus hydrogen peroxide). Various isomeric glycols are obtained depending on such factors as whether olefin XLIII is cis or trans and endo or exo, and whether a cis or a trans hydroxylation reagent is used. These various glycol mixtures can be separated into individual isomers by silica gel chromatography. However, this separation is usually not necessary, since all isomers of particularly glycol are equally useful as intermediates according to this invention and the processes outlined in Chart D to produce final products of formulas XL and XLI, and then, according to Chart A, B, and C to produce the other final products of this invention.
The transformation of glycol LI to the cyclic ketal of formula XXXVI (Chart D) is carried out by reacting said glycol with a dialkyl ketone of the formula ##EQU18## wherein R 11 and R 12 are alkyl of one to 4 carbon atoms, inclusive, in the presence of an acid catalyst, for example potassium bisulfate or 70% aqueous perchloric acid. A large excess of the ketone and the absence of water is desirable for this reaction. Examples of suitable dialkyl ketones are acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, and the like. Acetone is preferred as a reactant in this process.
Referring again to Chart D, cyclic ketal XXXVI is transformed to cyclic ketal XXXVII by alkylating with an alkylation agent of the formula ##EQU19## wherein R 10 , R 26 , and J' are as defined above, and Hal is chlorine, bromine, or iodine. Similarly, referring to Chart E, olefin XLIII is transformed to olefin XLIV by alkylating with an alkylation agent of the formula ##EQU20## wherein R 10 , R 26 , Z', and Hal are as defined above.
Any of the alkylation procedures known in the art to be useful for alkylating cyclic ketones with alkyl halides and haloalkanoic esters are used for the transformations of XXXVI to XXXVII and of XLIII to XLIV. See, for example, the above-mentioned Belgian Pat. No. 702,477 for procedures useful here and used there to carry out similar alkylations, e.g., employing the bicyclo enamines.
For these alkylations, it is preferred that Hal be bromo or iodo. Any of the usual alkylation bases, e.g., alkali metal alkoxides, alkali metal amides, and alkali metal hydrides, are useful for this alkylation. Alkali metal alkoxides are preferred, especially tert-alkoxides. sodium and potassium are preferred alkali metals. Especially preferred is potassium tert-butoxide. Preferred diluents for this alkylation are tetrahydrofuran and 1,2-dimethoxyethane. Otherwise, procedures for producing and isolating the desired formula-XXXVII and -XLIV compounds are within the skill of the art.
These alkylation procedures produce mixtures of alpha and beta alkylation products, i.e. a mixture of formula XXXVII products wherein part has the --CHR 26 --J'--COOR 10 moiety attached in alpha configuration, and wherein part has that moiety attached in beta configuration, or a mixture of the formula-XLIV products with the --CHR 26 --Z'--COOR 10 moiety in both alpha and beta configurations. When about one equivalent of base per equivalent of formula-XXXVI or -XLIII ketone is used, the alpha configuration usually predominates. Use of an excess of base and longer reaction times usually result in production of larger amounts of beta products. These alpha-beta isomer mixtures are separated at this stage or at any subsequent stage in the multi-step processes shown in Charts D and E. Silica gel chromatography is preferred for this separation.
The necessary alkylating agents for the above-described alkylations, e.g. compounds of the formulas ##EQU21## are prepared by methods known in the art. There are four groups of compounds encompassed by these two genera of alkylating agents.
Alkylating agents of the formula ##EQU22## include compounds of the formulas: ##SPC47##
Alkylating agents of the formula ##EQU23## include the above-listed compounds of formuls LIII and LIV, and also compounds of the following formulas ##SPC48##
These alkylating agents of formulas LIII to LVI are accessible to those of ordinary skill in the art. In one route, the ##EQU24## compounds are obtained from aldehyde or ketone reactants by a series of transformations as follows: ##EQU25## For example, methyl m-formylphenoxyacetate on reduction with sodium borohydride yields methyl m-(hydroxymethyl)-phenoxyacetate, which in turn is transformed to the formula-LIX compound, methyl m-(chloromethyl)phenoxyacetate, with thionyl chloride.
Those formula-LVII or formula-LVIII reactants which are not commercially available are advantageously prepared by adaptation of the Williamson ether syntheses, e.g. employing a hydroxy reactant and a halo-substituted acid or ester. Thus, the reaction ##SPC49##
wherein Hal is chloro, bromo, or iodo, preferably iodo, proceeds in the presence of strong base, for example sodium hydride when R 1 is a carbon-containing group, and lithium diisopropyl amide when R 1 is hydrogen. within the definitions of C g H 2g , C p H 2p , and C q H 2q , suitable reactants are readily available or are prepared by methods known to those skilled in the art.
Thus, when R 26 is hydrogen, and considering the variations of C g H 2g and C p H 2p , the aldehyde reactants include (o, m, or p)-hydroxybenzaldehyde, (o, m, or p-hydroxyphenyl)acetaldehyde, (o or p)-hydroxyhydrocinnamaldehyde, 4-(o or p-hydroxyphenyl)butyraldehyde, o-(2-hydroxyethyl)-benzaldehyde, and the like. Other aldehyde reactants are also accessible by methods known to those skilled in the art. For example, (o, m, or p-hydroxyethyl)benzaldehydes are obtained from (o, m, or p)-bromostyrene by the series of reactions: ##SPC50##
The reaction with ethylene oxide is carried out on a Grignard reagent prepared from the bromostyrene and magnesium. Substituted ethylene oxides are used to obtain substituted C p H 2p chains, e.g. propylene oxide, 1,2-epoxy-2-methylpropane, 1,2-epoxybutane, 1,2-epoxy-2,3-dimethylbutane, and the like. Instead of using ozone to form the aldehyde, hydroxylation and oxidation with osmium tetroxide and periodic acid are optional (see J. Org. Chem. 21, 478, 1956).
Compounds with C g H 2g chains are obtained by replacing
with ##SPC51##
e.g. 1-allyl-4-bromobenzene 1-allyl-2-chlorobenzene, 4-(o, m, or p-chlorophenyl)-1-butene, and the like. Compounds with C p H 2p chains are obtained by replacing ethylene oxide with suitable alkylating agents, e.g. trimethylene oxide, 1,3-epoxybutane, 1,3-epoxy-3-methylbutane and the like, or suitable reactions steps.
Other variations of the above reactions and reactants will be apparent to those skilled in the art. Thus, an alkene-substituted phenol is condensed with a halo-substituted acid or ester and thereafter transformed as an aldehyde to the halo alkylating agent within the scope of formula LIX by the following steps: ##SPC52##
Available for this series of reactions are (o, m, or p)-vinylphenol, p-allylphenol, 4-(o, m, or p-hydroxyphenyl)-1-butene, and the like.
Alternatively, a haloalkylphenol is condensed with a halo-substituted acid or ester by the reaction: ##SPC53##
Available are p-(2-bromoethyl)phenol, p-(3-bromobutyl)-phenol, and the like.
Considering the halo-substituted acid or ester reactants in the above ether syntheses and the variations of C q H 2q , there are a wide variety of reactants available, which will lead to the desired formula-LIX alkylating agent. For example: ##EQU26## wherein R 23 is hydrogen or alkyl of one to 5 carbon atoms, inclusive; Br--(CH 2 ) 2 --COOH, Br--C(CH 3 ) 2 --COOH, Br--C(C 2 H 5 ) 2 --COOH, BrC(CH 3 )(C 2 H 5 )--COOH, Br--CH(CH 3 )--CH 2 --COOH, Br--(CH 2 ) 3 )--COOCH 3 , Cl--CH(C 2 H 5 )--CH 2 --COOCH 3 , Cl--CH(n--C 3 H 7 )--CH 2 --COOCH 3 , Br--CH(CH 3 )--(CH 2 ) 2 --COOC 2 H 5 , Br--CH(CH 3 )--CH 2 --CH(CH 3 )--COOC 2 H 5 , Br--CH(CH 3 )--CH(CH 3 )--CH 2 --COOC 2 H 5 , Br--C(CH 3 ) 2 --CH 2 --CH(CH 3 )--COOC 2 H 5 , Cl--CH(n--C 4 H 9 )--CH 2 --COOC 2 H 5 , Cl--C(CH 3 ) 2 --CH 2 --COOC 2 H 5 , Br--CH(n--C 2 H 7 )--(CH 2 ) 2 --COOH, and Cl--CH(C 2 H 5 )--(CH.sub. 2) 2 --COOH are available. The preferred iodo reactants are obtained by methods known to those skilled in the art.
When C q H 2q has two alkyl groups attached to the ω or ω-1 carbon atom of the halo-substituted acid or ester reactants, it is preferred that halo be replaced with mesyloxy or tosyloxy prior to the ether synthesis, and that relative mild bases and reaction conditions be used, for example, potassium tert-butoxide in dimethyl sulfoxide.
In another route to the formula-LIX alkylating agents, the Williamson ether synthesis employs hydroxy-esters or acids of the formula HO--C q H 2q --COOR 1 for condensation with halo-substituted reactants as follows: ##SPC54##
For example, α,α'-dibromo-o-xylene is contacted with ethyl glycolate in the presence of sodium hydride to yield ethyl O-(bromomethyl)-benzyloxyacetate.
Typical halo reactants which are useful for this reaction are α-bromo-(o, m, or p)-chlorotoluene, 1-bromo-(2 or 3)-(2-bromoethyl)benzene, 1-(3-bromopropyl)-(1 or 2)-chlorobenzene, and 1-(4-bromobutyl)-1-chlorobenzene.
When C p H 2p has two alkyl groups attached to the carbon atom to which Hal is attached, it is preferred that this Hal be replaced with mesyloxy or tosyloxy prior to the ether synthesis and that relatively mild bases and reaction conditions be used.
Considering the hydroxy acid or ester reactants, there are available a wide range of suitable compounds within the scope of HO--C q H 2q --COOR 1 which will lead to the desired formula-LIX alkylating agent. For example: HOCH(CH 3 )--COOCH 3 , HOC(CH 3 ) 2 --COOH, HOCH(C 2 H 5 )--COOH, HOC(CH 3 )(C 2 H 5 )--COOH, HO(CH 2 ) 2 --COOC 2 H 5 , HOCH(CH 3 )--CH 2 --COOH, HOCH(n--C 3 H 7 )--COOH, HOC(n--C 3 H 7 )(CH 3 )--COOH, HOCH(C 2 H 5 )--CH 2 --COOH, HOCH(CH 3 )--(CH 2 ) 2 --COOH, HOCH(n-C 4 H 9 )--COOH, HOC(n-C 4 H 9 )(CH 3 )--COOH, HOCH(n-C 3 H 7 )--CH 2 --COOCH 3 ,HOCH(C 2 H 5 )--(CH 2 ) 2 --COOH, HOCH(n-C 5 H 11 )--COOH, HOCH(n-C 4 H 9 )--CH 2 --COOH, HOCH(n-C 3 H 7 )--(CH 2 ) 2 --COOH are available.
When a formula-LIX alkylating agent is desired in which there are two alkyl substituents on both carbon atoms attached to the oxa --O--, it is preferred that, if the halo-acid route be used, the halo atom on the acid be chloro and that freshly precipitated wet magnesium hydroxide in an inert solvent suspension be used as the base; and if the hydroxy-acid route be used, the --C p H 2p --Hal group is preferrably --C p H 2p --Cl. If the hydroxy-acid route is used with --C p H 2p --l, silver oxide is used as the base.
The alkylating agents of formulas LIII to LVI are esters. Any of the above acid forms are readily converted to esters. Variations in R 10 within the definition of R 10 herein are readily made by methods known in the art. The ester moiety is chosen according to the desired type of final oxa-phenylene PG-type product.
Formula-LVII aldehyde reactants which lead to the formula LIX alkylating agents are also obtained by reaction of halo-substituted aldehydes with hydroxy acids or ester reactants. Thus, there are employed o-(bromomethyl)benzaldehyde, p-chlorohydratropaldehyde, and the like.
When R 26 is alkyl, the formula-LIX ##EQU27## alkylating agents are prepared from the corresponding reactants wherein R 26 is methyl, ethyl, propyl, or butyl, or their isomers. For example m-bromo-α-methylstyrene reacts as follows: ##SPC55##
Typical halo-substituted ketones available for this purpose include (2', 3', or 4')-(bromo, chloro, or iodo)-acetophenone, (3' or 4')-bromopropiophenone, (3' or 4')-chlorobutyrophenone, and 4'-(bromo or chloro)-valerophenone. Other reactants leading to the R 26 (alkyl)-substituted formula-LIX alkylating agents are accessible to those skilled in the art.
Although the above methods are generally useful for preparing alkylating agents within the scope of formulas ##EQU28## above, there are preferred methods for preparing the formula-LIV compounds containing the --C.tbd.C--C j H 2j -- moiety.
Considering the compounds of the formula ##SPC56##
there is employed as starting material (o, m, or p-)vinylanisole in the following series of transformations: ##SPC57##
Herein, THP represents tetrahydropyranyl and R 28 represents ##SPC58##
The reagents and conditions for bringing about these transformations are known to those skilled in the art. Thus, in step a, reacting first with bromine and then with sodium amide in liquid ammonia yields the acetylenic derivative (see J. Am. Chem. Soc. 56, 2064, 1934). Step b utilizes boron tribromide for example. Step c proceeds either with ethylene chlorohydrin and a strong base, e.g., NaOH or KOH, followed by dihydropyran in the presence of an acid catalyst, or with the tetrahydropyranyl ether of the chlorohydrin and a strong base. Step d utilizes R 26 COCl in the presence of a strong base, e.g., sodium amide, phenyllithium, or sodium triphenylmethane. Alternatively, if R 26 is desirably hydrogen, paraformaldehyde is employed (see J. Am. Chem. Soc. 92, 6314 (1970). The reaction in step e is done with a metal hydride, e.g., sodium borohydride. In step f thionyl chloride yields the formula-LX chloro compounds. Finally, in step g the THP moiety is selectively removed by mild hydrolysis in acid medium and the terminal --CH 2 OH moiety is oxidized to --COOH, e.g. with the Jones reagent. The alkylating agent is converted by known means to an ester, as defined by R 10 , to yield the desired compounds.
Considering the compounds of the formula ##SPC59##
the above series of transformations are used, except that in step c ClCH 2 CH 2 OH is replaced by Cl--C q H 2q --CH 2 OH. There are obtained in step f compounds of the formula ##SPC60##
wherein C q H 2q , Hal, R 26 and THP are as defined above. Thereafter these formula-LXI compounds are transformed as in step g above to the desired compounds.
Considering the compounds of the formula ##SPC61##
there are employed as starting materials the ar-halostyrenes. These are transformed by the following steps: ##SPC62##
Thereafter, these formula-LXII compounds are transformed as in step g above to the desired compounds. In step a, the halo compounds are converted to a Grignard reagent with magnesium and thence reacted with ethylene oxide. In step b, the hydroxy group is converted to --OTHP with dihydropyran, the acetylenic moiety is formed as in step a leading to the formula-LX compounds above, and the THP moiety removed by mild acid hydrolysis. In step c, the chain is extended by reaction with Hal--CH 2 CH 2 OH, preferably the bromo or iodo derivatives, in the presence of strong base, e.g., phenyl lithium sodium triphenylmethane, or sodium hydride. Thereafter, in step d the transformations follow the general scheme of steps d-f leading to the formula-LX compound to yield the formula-LXII compounds. Transformation as in step g above yields the desired compounds.
Consdering the compounds of the formula ##SPC63##
the series of transformations in the paragraph immediately preceeding are used, except that in step c Hal--CH 2 CH 2 OH is replaced by Hal--C q H 2q --CH 2 OH. There are obtained in step d compounds of the formula ##SPC64##
These formula-LXIII compounds are transformed as in step g above to the desired esters.
Considering the compounds of the formula ##SPC65##
there are employed as starting materials anisolyl aliphatic acids, e.g., anisolylacetic acid, in the following steps: ##SPC66##
In step a, the carboxyl group is reduced with a metal hydride, e.g. lithium aluminum hydride. In step b, where Ts represents the toluenesulfonyl ("tosyl") moiety, the reaction is carried out with toluenesulfonyl chloride and pyridine. In step c, the acetylenic moiety is introduced with lithium acetylide (see J. Am. Chem. Soc. 80, 6626, 1958) to yield the formula-LXIV intermediates. Subsequent steps in d to form the formula-LXV compounds follow from steps b-f for the formula-LX compounds above. Finally, the formula-LXV compounds are transformeda s in step g above to the desired esters.
Considering the compounds of the formula ##SPC67##
there are employed as starting materials benzenedialiphatic acids, e.g., benzenediacetic acid, in the following steps: ##SPC68##
In step a, the carboxyl groups are reduced with a metal hydride, e.g. lithium aluminum hydride. In step b, reaction with toluenesulfonyl halide yields the bistosyl derivative. In step c one tosyloxy group is replaced by reaction with HO--C q H 2q --CH 2 OTHP in the presence of sodium hydride in an inert solvent, e.g. dimethyl formamide. In step d, the acetylenic moiety is introduced as in forming the formula-LXIV compounds above. Subsequent steps in e to form the formula-LXVI compounds follow from steps b-f for the formula-LX compounds above. Finally, the formula-LXVI compounds are transformed as in step g above to the desired esters.
Variations in the above formula LX-to-LXVI compounds and their corresponding ester alkylating agents as to chain length or branching in the C g H 2g , C j H 2j , C p H 2p , and C q H 2q moieties and as to the identity of R 1 or R 26 , within the scope of these terms as herein defined, are available to those skilled in the art making use of the principles disclosed herein.
Other modifications which are encompassed within this disclosure include the use of alkylating agents wherein Hal is replaced by hydrocarbonsulfonyl, e.g. tosyl or mesyl (methanesulfonyl) groups. Furthermore, the formula-LX, -LXI, -LXII, -LXIII, -LXV, and -LXVI compounds are alternatively employed as alkylating agents, instead of the corresponding esters, and the alkylated formula-XXXVI and -XLIII compounds subsequently converted to the desired formula-XXXVII and -XLIV compounds by mild hydrolysis to remove the THP moiety, oxidation to convert the --CH 2 OH moiety to --COOH, and, optionally, esterification to the desired R 1 identity.
The cis and trans ethylenic alkylating agents of formulas LV and LVI above are preferably prepared by cis or trans reduction of the corresponding formula-LIV acetylenic compounds prepared as above, or by cis or trans reduction of any earlier acetylenic intermediate in which both ends of the acetylenic bond are substituted, i.e., not hydrogen as in the moiety HC.tbd.C--. Alternatively, this cis or trans reduction is carried out on any subsequent acetylenic reaction product leading up to and including the final acetylenic alkylating agent of formula LIV.
For these cis reductions of acetylenic bonds, it is advantageous to use hydrogen plus a catalyst which catalyzes hydrogenation of --C.tbd.C-- only to cis --CH=CH--. Such catalysts and procedures are well known to the art. See, for example, Fieser et al., "Reagents for Organic Syntheses", pp. 566-567; John Wiley and Sons, Inc., New York, N.Y. (1967). Palladium (5%) on barium sulfate, especially in the presence of pyridine as a diluent, is a suitable catalyst for this purpose. Alternative reagents useful to transform these acetylenic compounds to cis-ethylenic compounds are bis(3-methyl-2-butyl)borane ("disiamylborane") and diisobutyl-aluminum hydride.
For trans reductions of the acetylenic bond, except for those compounds containing halogen, it is advantageous to use sodium or lithium in liquid ammonia or a liquid alkylamine, e.g., ethylamine. When the moiety HO--CH 2 --C.tbd.C-- is present in the acetylenic compound being reduced, the use of lithium aluminum hydride gives trans reduction of the triple bond. Procedures for these trans reductions are known in the art. See, for example, Fieser et al., above cited, pp. 577, 592-594, and 603, and J. Am. Chem. Soc. 85, 622 (1963).
The alkylating agents of the formulas ##SPC69##
are available by methods known to those skilled in the art.
Thus, the above-described intermediates within the scope of ##SPC70##
are transformed to the phosphoranes and condensed with halo-substituted ketones of the formula ##EQU29## wherein THP is tetrahydropyranyl, by the Wittig reaction (Organic Reactions, Vol. 14, p. 270, Wiley, 1965). Mixtures of the cis and trans isomers of formulas LXVII and LXVIII are usually obtained, which are separable by methods known in the art. Higher proportions of the cis isomers are obtained in the presence of Lewis bases; higher proportions of the trans isomers result by employing the phosphonate modification (D. H. Wadsworth et al., J. Org. Chem. 30, 680 (1965)). Thereafter, hydrogen on the terminal carboxyl group is replaced with R 10 , THP is replaced with hydrogen, and the terminal hydroxyl group replaced with Hal, for example with PBr 3 or PCl 3 .
Alternatively, an intermediate of the formula ##SPC71##
is condensed by the Wittig reaction with a phosphorane or phosphonate derived from ##EQU30## Subsequently, the terminal hydroxy group is replaced with Hal by suitable reagents, for example PBr 3 or PCl 3 .
Concerning the alkylation of the cyclopentane ring, another useful alkylation procedure utilizes an intermediate enamine. That enamine is prepared by mixing either the formula-XXXVI ketal or the formula-XLIII olefin ketone with a secondary amine of the formula ##EQU31## wherein R 24 and R 25 are alkyl or alkylene linked together through carbon or oxygen to form together with a nitrogen a 5 to 7-numbered heterocyclic ring. Examples of suitable amines are diethylamine, dipropylamine, dibutylamine, dihexylamine, dioctylamine, dicyclohexylamine, methylcyclohexylamine, pyrrolidine, 2-methylpyrrolidine, piperidine, 4-methylpiperidine, morpholine, hexamethylenimine, and the like.
The enamine is prepared by heating a mixture of the formula-XXXVI ketal or the formula-XLIII olefin ketone with an excess of the amine preferably in the presence of a strong acid catalyst such as an organic sulfonic acid, e.g., p-toluenesulfonic acid, or an inorganic acid, e.g., sulfuric acid. It is also advantageous to carry out this reaction in the presence of a water-immiscible diluent, e.g., benzene or toluene, and to remove water by azeotropic distillation as it is formed during the reaction. Then, after water formation ceases, the enamine is isolated by conventional methods.
The enamine is then reacted with a haloester, ##EQU32## to give the desired formula-XXXVII or -XLIV product. This reaction of the enamine is carried out by the usual procedures. See "Advances in Organic Chemistry," Interscience Publishers, New York, N.Y., Vol. 4, pp. 25-47 (1963) and references cited therein. In addition to halogen, R 29 in ##EQU33## can also be tosylate, mesylate, and the like. It is especially preferred that R 29 be bromine or iodine. Dimethylsulfoxide is especially useful as a diluent in the reaction of the enamine with the haloester.
Referring again to Chart D, after alkylation as discussed above, cyclic ketal XXXVII is transformed to glycol XXXVIII by reacting the cyclic ketal with an acid with pK less than 5. Suitable acids and procedures for hydrolyzing cyclic ketals to glycols are known in the art. Suitable acids are formic acid, hydrochloric acid, and boric acid. Especially preferred as diluents for this reaction are tetrahydrofuran and β-methoxyethanol.
Referring again to Chart E, after alkylation as discussed above, olefin XLIV is hydroxylated to glycol XLV. As discussed above, the divalent moiety --Z'-- includes the moieties ##SPC72##
and ##SPC73##
wherein C g H 2g , C j H 2j and C q H 2q are as defined above. When Z' is ##SPC74##
this hydroxylation of XLIV is carried out as described above for the hydroxylation of olefin XLIII to glycol LI, i.e., with any of the known reagents and procedures described in Gunstone, above cited. When Z' is ##SPC75##
some of the reagents and procedures described by Gunstone tend to attack the acetylenic linkage as well as the ethylenic linkage of the formula-XLIV olefin. Therefore it is preferred to use a hydroxylation reagent and procedure which attacks the ethylenic linkage preferentially. For this, it is preferred to carry out hydroxylation of these acetylenic formula-XLIV olefins with organic peracids, e.g., performic acid, peracetic acid, perbenzoic acid, and m-chloro-perbenzoic acid, as described by Gunstone, above cited, pp. 124-130.
As discussed above regarding the hydroxylation of unalkylated olefin XLIII to unalkylated glycol LI, various isomeric glycols are obtained by hydroxylation of the formula-XLIV alkylated olefin. The particular formula-XLV glycol or glycol mixture obtained depends on such factors as whether the olefin XLIV is cis or trans and endo or exo, and whether a cis or a trans hydroxylation takes place. However, all of the isomeric formula-XLIV glycols and the various glycol mixtures are equally useful as intermediates according to this invention and the processes of Chart E to produce final products of formulas XLVII and XLVIII, and then according to Charts A, B, and C, to produce the other final products of this invention. Therefore, it is usually not necessary to separate individual formula-XLV glycol isomers before proceeding further in the synthesis, although that separation can be accomplished by silica gel chromatography.
It is preferred that glycols XXXVIII and XLV of Charts D and E, respectively, be free of phenolic hydroxyl substituents before the alkanesulfonation step. If any of the intermediate formula-XXXVIII or formula-XLV compounds have phenolic hydroxyls, these hydroxyls are readily converted to tetrahydropyranyloxy (OTHP) by reaction with dihydropyran, e.g. in the presence of a catalytic amount of POCl 3 . The --OTHP group is subsequently replaced by OH under mildly acidic conditions.
Referring again to Charts D and E, bis(alkanesulfonic acid) esters XXXIX and XLVI are prepared by reacting glycols XXXVIII and XLV, respectively, with an alkanesulfonyl chloride or bromide, or with an alkanesulfonic acid anhydride, the alkyl in each containing one to 5 carbon atoms, inclusive. Alkanesulfonyl chlorides are preferred for this reaction. The reaction is carried out in the presence of a base to neutralize the byproduct acid. Especially suitable bases are tertiary amines, e.g., dimethylaniline or pyridine. It is usually sufficient merely to mix the two reactants and the base, and maintain the mixture in the range 0° to 25°C. for several hours. The formula-XXXIX and XLVI bis(sulfonic acid) esters are then isolated by procedures known to the art.
Referring now to Chart D, bis(sulfonic acid) esters XXXIX are transformed either to oxa-phenylene PGE-type compounds XL, or to oxa-phenylene PGA-type compounds XLI. Referring to Chart E, bis(sulfonic acid) esters XLVI are transformed either to oxa-phenylene PGE-type compounds XLVII, or to oxa-phenylene PGA-type compounds XLVIII.
The transformations of XXXIX and XLVI to the PGE-type compounds XL and XLVII, respectively, are carried out by reacting bis-esters XXXIX and XLVI with water in the range about 0° to about 60°C. In making the oxa-phenylene PGE 1 compounds, 25° C. is a suitable reaction temperature, the reaction then proceeding to completion in about 5 to 20 hours. It is advantageous to have a homogenous reaction mixture. This is accomplished by adding sufficient of a water-soluble organic diluent which does not enter into the reaction. Acetone is a suitable diluent. The desired product is isolated by evaporation of excess water and diluent if one is used. The residue contains a mixture of formula-XL or formula-XLVII C-15 epimers which differ in the configuration of the side chain hydroxy, that being either "natural" or "epi," i.e. α or β. These are separated from by-products and from each other by silica gel chromatography. A usual by-product is the mono-sulfonic acid ester of formula XLII (Chart D) or formula XLIX (Chart E). These mono-sulfonic acid esters are esterified to the formula-XXXIX or -XLVI bis(sulfonic acid) esters, respectively, in the same manner described above for the transformation of glycol XXXVIII or XLV to bis-ester XXXIX or XLVI and thus are recycled back to additional formula-XL or -XLVII final product.
The transformations of XXXIX and XLVI to the PGA type compounds XLI and XLVIII, respectively, are carried out by heating bis-esters XXXIX and XLVI in the range 40° to 100° C. with a combination of water, a base characterized by its water solution having a pH 8 to 12, and sufficient inert water-soluble organic diluent to form a basic and substantially homogenous reaction mixture. A reaction time of one to 10 hours is usually used. Preferred bases are the water-soluble salts of carbonic acid, especially alkali metal bicarbonates, e.g., sodium bicarbonate. A suitable diluent is acetone. The products are isolated and separated as described above for the transformation of bis-esters XXXIX and XLVI to PGE-type products XL and XLVII. The same mono-sulfonic acid esters XLII and XLIX observed as by-products in those transformations are also observed during preparation of PGA-type products XLI and XLVIII.
For the transformations of bis(sulfonic acid) esters XXXIX and XLVI to final products XL, XLI, XLVII, and XLVIII, it is preferred to use the bis-mesyl esters, i.e., compounds XXXIX and XLVI wherein R 13 is methyl.
Referring again to Charts D and E, the configuration of the ##EQU34## moiety in the formula-XXXIX bis-esters or the configuration of the ##EQU35## moiety in the formula-XLVI bis-esters does not change during these transformations of XXXIX to XL, XLI, and XLII and of XLVI to XLVII, XLVIII, and XLIX. Therefore, when in formula XXXIX for example, J' is ##SPC76##
G' is --(CH 2 ) 4 --CH 3 , and R 2 , R 9 and R 26 are hydrogen, natural- and epi-configuration 3-oxa-4,5-inter-o-phenylene-PGE 1 esters (XL) are obtained when ##EQU36## is attached initially (XXXIX) in alpha configuration, and natural- and epi-configuration 8-iso-3-oxa-4,5-inter-o-phenylene-PGE 1 esters (XL) are obtained when that moiety is attached in beta configuration. Similarly, when in formula XXXIX, J' is ##SPC77##
is --(CH 2 ) 4 --CH 3 , and R 2 , R 9 , and R 26 are hydrogen, natural- and epi-configuration 5,6-dehydro-3-oxa-4,5-inter-p-phenylene-PGE 2 esters are obtained when ##EQU37## is attached initially in alpha configuration, and the corresponding 8-iso compounds are obtained when that moiety is attached in beta configuration. The same retention of ##EQU38## configuration occurs when formula-XLI and XLII compounds are produced, and a similar retention bis-esters. ##EQU39## configuration occurs when formula-XLVII, XLVIII, and XLIX compounds are produced from formula-XLVI bis-esters
The PGE 3 -type oxa-phenylene compounds encompassed by formula XXXII are prepared by the transformations shown in Chart F, wherein C n H 2n , M', Q, R 2 , R 5 , R 9 R 10 R 13 , THP, and ˜ are as defined above. ##SPC78##
Starting material, previously discussed, is converted to the formula-LXIX compound by several steps known in the art, employing first a Wittig reaction of a phosphonium salt of a haloalkyne of the formula BR--CHR 2 --C n H 2n --C.tbd.C--R 5 wherein C n H 2n , R 2 , and R 5 are as defined above. See, for example, U. Axen et al., Chem. Comm. 1969, 303, and ibid. 1970, 602.
Compound LXIX is then alkylated with an alkylation agent of the formula Hal--CH 2 --C.tbd.C--M'--COOR 10 wherein M', R 10 , and Hal are as defined above, i.e. M' is ##SPC79##
wherein C j H 2j , C p H 2p , and C q H 2q are as defined above,R 10 is the same as the definition of R 1 except that R 10 does not include hydrogen, and Hal is chloro, bromo, or iodo. These alkylating agents have been discussed above in connection with Charts D and E and the procedures for alkylation are similar to those employed in preparing the acetylenic compounds above. See also Axen et al., references cited.
Accordingly, for the preparation of 3-oxa-3,5-inter-m-phenylene-4-nor-PGE 3 compounds of formula XXXII wherein C j H 2j and C p H 2p are valence bonds, there is used an alkylating agent of the formula ##SPC80##
prepare, for example, from compound LX as discussed above.
Referring again to Chart F, after alkylation, compound LXX is hydroxylated to glycol LXXI. Hydroxylation reagents and procedures for this purpose are known in the art. See also Axen et al., references cited.
Bis(alkanesulfonic acid) esters LXXII are prepared by reacting glycol LXXI with an alkanesulfonyl chloride or bromide, for example methanesulfonyl chloride in the presence of a tertiary amine, by methods known in the art.
Referring again to Chart F, bis(sulfonic acid) esters LXXII are transformed to oxa-phenylene bisdehydro PGE 3 -type compounds LXXIII by reaction with water in the range about 0° to about 60° C., preferably in an acetone-water mixture, as known in the art and discussed hereinabove. See also Axen, references cited.
Transformation of LXXIII to the PGE 3 -type compounds LXXIV is accomplished by hydrogenation of LXXIII using a catalyst which catalyzes hydrogenation of --C.tbd.C-- only to cis--CH=CH--, as known in the art and discussed hereinabove. Preferred is Lindlar catalyst in the presence of quinoline, see Axen, references cited.
The product is a mixture of formula-LXXIV C-15 epimers which are separated from by-products and from each other by silica gel chromatography.
The transformations of the formula-LXXIV PGE 3 -type products to the corresponding PGF 3 , PGA 3 , and PGB 3 products are carried out by the steps shown in Chart A, discussed hereinabove.
The formula-LX and XLVII oxa-phenylene PGE-type compounds and the formula-XLI and XLVIII oxa-phenylene PGA-type compounds shown in Charts D and E and the formula-LXXIV oxa-phenylene PGE 3 -type compounds shown in Chart F are all R 10 carboxylic acid esters, wherein R 10 is as defined above. Moreover when those PGE-type and PGA-type R 10 esters are used to prepare the other oxa-phenylene prostaglandin-like compounds according to Charts A, B, and C, corresponding R 10 esters are likely to be produced, especially in the case of the oxa-phenylene PGF-type compounds. For some of the uses described above, it is preferred that the novel formula XVI-to-XXXV oxa-phenylene prostaglandin-like compounds of this invention be in free acid form, or in salt form which requires the free acid as a starting material. Likewise, when a formula XVI-to-XXXV oxa-phenylene prostaglandin-like compound is available as an ester, say the methyl ester, and another ester is desired, it is usually necessary to convert the available ester to the free acid form and from it prepare the desired ester. Esters are prepared by methods known in the art or described herein, for example by reaction with diazohydrocarbons.
The PGF-type esters of formulas XX-XXIII and XXXIII and the PGB-type compounds of formulas XXVIII-XXXI and XXXV are easily hydrolyzed or saponified to the free acids by the usual known procedures, especially when R 1 (R 10 ) is alkyl of one to 4 carbons, inclusive, preferably methyl or ethyl.
On the other hand, the PGE type esters of formulas XVI-XIX and XXXII and the PGA type esters of formulas XXIV-XXVII and XXXIV are difficult to hydrolyze or saponify without causing unwanted structural changes in the desired acids. There are two other procedures to make the free acid forms of these PGE- and PGA-type compounds.
One of those procedures is applicable mainly in preparing the free acids by subjecting their alkyl esters to the acylase enzyme system of a microorganism species of Subphylum 2 of Phylum III, and thereafter isolating the acid. See West Germany Offenlegungsschrift No. 1,937,678; Derwent Farmdoc No. 6863R. This enzymatic hydrolysis is also applicable to the above PGF- and PGB-type alkyl esters. Another method using an esterase enzyme composition from P. homomalla is described in U.S. Pat. No. 3,761,356.
Another procedure for making the free acids of the above PGE- and PGA-type compounds involves treatment of certain haloethyl esters of those acids with zinc metal and an alkanoic acid of 2 to 6 carbon atoms, preferably acetic acid. Those haloethyl esters are the esters wherein R 10 is ethyl substituted in the β-position with 3 chloro, 2 or 3 bromo, or one, 2, or 3 iodo. Of those haloethyl moieties, β,β,β-trichloroethyl is preferred. Zinc dust is preferred as the physical form of the zinc. Mixing the haloethyl ester with the zinc dust at about 25° C. for several hours usually causes substantially complete replacement of the haloethyl moiety of the formula XVI-XIX, XXXII, XXIV-XXVII, and XXXIV ester with hydrogen. The free acid is then isolated from the reaction mixture by procedures known to the art. This procedure is also applicable to the production of PGF- and PGB-type free acids.
Formula-XXXVII cyclic ketals and formula XLIV olefins wherein R 10 is haloethyl as above defined are necessary as intermediates for this route to the final PGE, PGF, PGA, and PGB type free acids. These formula-XXXVII and -XLIV haloethyl ester intermediates can be prepared by alkylation of cyclic ketal XXXVI (Chart D) or olefin XLIII (Chart E), respectively, with the appropriate formula LIII-to-LVI or LXVII-LXVIII alkylating agent wherein R 10 is haloethyl as above defined. However, preferred routes of the formula-XXXVII and -XLIV haloethyl ester intermediates are shown in Charts G and H.
In Charts G and H, G, J', R 2 , R 9 , R 26 , R 11 , R 12 , Z', and ˜ are as defined above. Haloethyl represents ethyl substituted in the β-position with 3 chloro, or 2 or 3 bromo, or 1, 2, or 3 iodo, preferably --CH 2 CCl 3 . R 15 represents alkyl of one to 4 carbon atoms, inclusive, preferably methyl or ethyl. ##SPC81## ##SPC82##
Compound LXXVI in Chart G is within the scope of compound XXXVII in Chart D. Compound LXXXII in Chart H is within the scope of compound XLIV in Chart E. These ketones LXXVI and LXXXII are reduced to corresponding hydroxy compounds LXXVII and LXXXIII, respectively, with a carbonyl reducing agent, e.g., sodium borohydride, as described above in discussion of Chart A. Then, hydroxy esters LXXVII and LXXXIII are saponified by known procedures to hydroxy acids LXXVIII and LXXXIV, respectively. These two hydroxy acids are transformed to keto haloethyl esters LXXXI and LXXXVI, respectively, by oxidation of the hydroxy group to keto and esterification of the carboxyl group to --COO-haloethyl. As shown in Charts G and H, these two reactions are carried out in either order. However, it is preferred to oxidize first and then esterify.
Hydroxy acids LXXVIII and LXXXIV are oxidized to keto acids LXXX and LXXXVI, respectively, and hydroxy haloesters LXXIX and LXXXV are oxidized to keto haloesters LXXXI and LXXXVII, respectively, by reaction with an oxidizing agent which does not attack other parts of these molecules, especially the cyclic ketal group of compounds LXXVIII and LXXIX or ethylenic linkage of compounds LXXIV and LXXXV. An especially useful reagent for this purpose is the Jones reagent, i.e., acidic chromic acid. Acetone is a suitable diluent for this purpose, and a slight excess of oxidant and temperatures at least as low as about 0° C., preferably about -10° to about -20° C. should be used. The oxidation proceeds rapidly and is usually complete in about 5 to about 30 minutes. Excess oxidant is destroyed, for example, by addition of a lower alkanol, advantageously isopropyl alcohol, and the aldehyde is isolated by conventional methods, for example, by extraction with a suitable solvent, e.g., diethyl ether. Other oxidizing agents can also be used. Examples are mixtures of chromium trioxide and pyridine or mixtures of dicyclohexylcarbodiimide and dimethyl sulfoxide. See, for example, J. Am. Chem. Soc. 87, 5661 (1965).
Haloethyl esters LXXIX, LXXXI, LXXXV, and LXXXVII are prepared by reacting agents LXXVIII, LXXX, LXXXIV, and LXXXVI respectively, with the appropriate haloethanol, e.g., β,β,β-trichloroethanol, in the presence of a carbodiimide, e.g., dicyclohexylcarbodiimide, and a base, e.g., pyridine, preferably in the presence of an inert liquid diluent, e.g., dichloromethane, for several hours at about 25° C.
As described above, the alkylations of cyclic ketal XXXVI to XXXVII (Chart D) and olefin XLIII and XLIV (Chart E) usually produce mixtures of alpha and beta alkylation products with respect to the ##EQU40## moities. Also as described above, those two isomers lead to different final products, alpha leading to the PG-type series and beta leading to the 8-iso-PG-type series. If a compound in one or the other of those two series is preferred, there are two methods for favoring production of the preferred final product.
One of those methods involves isomerization of the final product of formulas XVI to XXXV. Either the alpha isomer of a formula XVI-to-XXXV compound, ester or free acid, or the corresponding beta isomer is maintained in a inert liquid diluent in the range 0° to 80° C. and in the presence of a base characterized by its water solution having a pH below about 10 until a substantial amount of the isomer has been isomerized to the other isomer, i.e., alpha to beta or beta to alpha. Preferred bases for this purpose are the alkali metal salts of carboxylic acids, especially alkanoic acids of 2 to 4 carbon atoms, e.g., sodium acetate. Examples of useful inert liquid diluents are alkanols of one to 4 carbon atoms, e.g., ethanol. This reaction at about 25° takes about one to about 20 days. Apparently an equilibrium is established. The mixtures of the two isomers, alpha and beta, are separated from the reaction mixture by known procedures, and then the two isomers are separated from each other by known procedures, for example, chromatography, recrystallization, or a combination of those. The less preferred isomer is then subjected to the same isomerization to produce more of the preferred isomer. In this manner by repeated isomerizations and separations, substantially all of the less preferred isomer of the formula XVI-to-XXXV compound is transformed to more preferred isomer.
The second method for favoring production of a preferred formula XVI-to-XXXV isomer involves any one of the keto intermediates of formulas XXXVII, XXXVIII, XLIV, XLV, LXX, or LXXI (Charts D, E, and F). Either the alpha form or the beta form of one of those intermediates is transformed to a mixture of both isomers by maintaining one or the other isomer, alpha or beta, in an inert liquid diluent in the presence of a base and in range 0°to 100° C. until a substantial amount of the starting isomer has been isomerized to the other isomer. Preferred bases for this isomerization are alkali metal amides, alkalie metal alkoxides, alkali metal hydrides, and triarylmethyl alkali metals. Especially preferred are alkali metal tert-alkoxides of 4 to 8 carbon atoms, e.g., potassium tert-butoxide. This reaction at about 25° C. proceeds rapidly (one minute to several hours). Apparently an equilibrium mixture of both isomers is formed, starting with either isomer. The isomer mixtures in the equilibrium mixture thus obtained are isolated by known procedures, and then the two isomers are separated from each other by known procedures, for example, chromatography. The less preferred isomer is then subjected to the same isomerization to produce more of the preferred isomer. In this manner, by repeated isomerizations and separations, substantially all of the less preferred isomer of any of these intermediates in transformed to the more preferred isomer. Cyclic ketalketone intermediates of formula XXXVII are preferred over the other intermediates for this isomerization procedure.
The novel oxa-phenylene PGE, PGF, PGA and PGB type compounds of formula XVI to XXXV wherein R 2 is alkyl of one to 4 carbon atoms, inclusive, preferably methyl or ehtyl, are preferred over the corresponding oxa-phenylene PGE, PGF, PGA, and PGB type compounds in which R 2 is hydrogen for the above-described pharmacological purposes.
These 15-alkyl prostaglandin analogs are suprisingly and unexpectedly more useful than the corresponding 15-hydrogen compounds for the reason that they are substantially more specific with regard to potency in causing prostaglandin-like biological responses, and have substantially longer duration of biological activity. For that reason, fewer and smaller doses of these 15-alkyl prostaglandin analogs are needed to attain the desired pharmacological results.
Although the above-mentioned 15-alkyl compounds are produced by the methods outlined above in Charts A-F, the preferred methods are set forth in Chart I and J as follows.
In Chart I is shown the transformation of 15-alkyl PGF-type acids and alkyl esters to the corresponding PGE-type acids and alkyl esters by oxidation. For this purpose, and oxidizing agent is used which selectively oxidizes secondary hydroxy groups to carbonyl groups in the presence of carbon-carbon double bonds. Formula LXXXVIII in Chart I includes optically active compounds as shown and racemic compounds of that formula and the mirror images thereof, and also the 15-epimers of both of those, i.e., wherein the configuration at C-15 is β rather than α as shown. Also in Chart I, E', G, J', R 1 and R 26 are as defined above, and R 16 is alkyl of one to 4 carbon atoms.
For the transformations of Chart I, the β-hydroxy isomers of reactant LXXXVIII are preferred starting materials when the carboxyl side chain is alpha, although the corresponding α-hydroxy isomers are also useful for this purpose.
Oxidation reagents useful for the transformation set forth in Chart I are known to the art. An especially useful reagent for this purpose is the Jones reagent, i.e., acidified chromic acid. See J. Chem. Soc. 39 (1946). A slight excess beyond the amount necessary to oxidize one of the secondary hydroxy groups of the formula-LXXXVIII reactant is used. Acetone is a suitable diluent for this purpose. Reaction temperatures at least as low as about 0° C. should be used. ##SPC83##
Preferred reaction temperatures are in the range -10° to -50° C. The oxidation proceeds rapidly and is usually complete in about 5 to 20 minutes. The excess oxidant is destroyed, for example by addition of a lower alkanol, advantageously, isopropyl alcohol, and the formula-LXXXIX PGE-type product is isolated by conventional methods.
Examples of other oxidation reagents useful for the Chart H transformations are silver carbonate on Celite (Chem. Commun. 1102 (1969)), mixtures of chromium trioxide and pyridine (Tetrahedron Letters 3363 (1968), J. Am. Chem. Soc. 75, 422 (1953), and Tetrahedron, 18, 1351 (1962)), mixtures of sulfur trioxide in pyridine and dimethyl sulfoxide (J. Am. Chem. Soc. 89, 5505 (1967)), and mixtures of dicyclohexylcarbodiimide and dimethyl sulfoxide (J. Am. Chem. Soc. 87, 5661 (1965)).
The novel 15-alkyl oxa-phenylene PGF.sub.α- and PGF.sub.β-type acids and esters of formulas XX-XXIIII and XXXIII wherein R 2 is one to 4 carbon atoms, inclusive, are preferably prepared from the corresponding 15-hydrogen compounds by the sequence of transformations shown in Chart J, wherein formulas XC through XCIV, inclusive, include optically active and racemic natural- and epi-configuration compounds of those formulas and the mirror images thereof. Also in Chart J, R 16 is alkyl of one to 4 carbon atoms, inclusive, and E', G, Hal, J', R 1 , R 26 , and ˜ are as heretofore defined; G" in formula XCII is the same as G except that T is replaced by T", wherein T" is the same as T above except that, in R 6 , --Si(R 8 ) 3 replaces hydrogen. Also in Chart J, R 8 is alkyl of one to 4 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl substituted with one or 2 fluoro, chloro, or alkyl of one to 4 carbon atoms inclusive, and R 17 is R 1 as defined above or silyl of the formula-Si--(R 8 ) 3 wherein R 8 is as defined above. The various R 8 's of a --Si(R 8 ) 3 moiety are alike or different. For example, a --Si(R 8 ) 3 can be trimethylsilyl, dimethylphenylsilyl, or methylphenylbenzylsilyl. Examples of alkyl of one to 4 carbon atoms, inclusive, are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and tert-butyl. Examples of aralkyl of 7 to 12 carbon atoms, inclusive, are benzyl, phenethyl, α-phenylethyl, 3-phenylpropyl, α-naphthylmethyl, and 2-(β-naphthyl)ethyl. Examples of phenyl substituted with one or 2 fluoro, chloro, or alkyl of one to 4 carbon atoms, inclusive, are p-chlorophenyl, m-fluorophenyl, o-tolyl, 2,4-dichlorophenyl, p-tert-butylphenyl, 4-chloro-2-methylphenyl, and 2,4-dichloro-3- methylphenyl.
In Chart J, the final PGF.sub.α and PGF.sub.β-type products are those encompassed by formulas XCIII and XCIV, respectively.
The initial optically active or racemic reactants of formula XC in Chart J i.e., the oxa-phenylene PGF 1 -, PGF 2 -, 5,6-dehydro-PGF 2 -, and dihydro-PGF 1 -type compounds in their α and β forms, and their esters, are prepared by methods described herein. Thus, racemic oxa-phenylene dihydro-PGF 1 .sub.α- and -PGF 1 .sub.β-type compounds, and their esters are prepared by catalytic hydrogenation of the corresponding racemic oxa-phenylene PGF 1 .sub.α or PGF 2 .sub.β, and PGF 1 .sub.β or PGF 2 .sub.βtype compounds, respectively, e.g. in the presence of 5% palladium-on-charcoal catalyst in ethyl acetate solution at 25° C. and one atmosphere pressure of hydrogen.
The heretofore-described acids and esters of formula XC are transformed to the corresponding intermediate 15-dehydro acids and esters of formula XCI, by oxidation with reagents such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, activated manganese dioxide, or nickel peroxide (see Fieser et al., "Reagents for Organic Syntheses," John Wiley & Sons, Inc., New York, N.Y. pp. 215, 637, and 731). Alternatively, and especially for the formula-XC reactants wherein E' is --CH 2 CH 2 and J' is L as defined above, these oxidations are carried out by oxygenation in the presence of the 15-hydroxyprostaglandin dehydrogenase of swine lung (see Arkiv for Kemi 25, 293 (1966)). These reagents are used according to procedures known in the art. See, for example, J. Biol. Chem. 239, 4097 (1964).
Referring again to Chart J, intermediate compounds of formula XCI are transformed to silyl derivatives of formula XCII by procedures known in the art. See, for example, Pierce, "Silylation of Organic Compounds," Pierce Chemical Co., Rockford, Ill. (1968). Both hyroxy groups of the formula-XCI reactants are thereby transformed to --O--Si(R 8 ) 3 moieties wherein R 8 is as defined above, and sufficient of the silylating agent is used for that purpose according to known procedures. When R 1 in the formula-XCI intermediate is hydrogen, the --COOH moiety thereby defined is simultaneously transformed to --COO--Si(R 8 ) 3 , additional silylating agent being used for this purpose. This latter transformation is aided by excess silylating agent and prolonged treatment. Likewise, when R 6 in T of the formula-XCI intermediate is hydrogen, the phenolic hydroxyl thereby defined is simultaneously transformed to --O--Si(R 8 ) 3 in the silylation step. G" in formula XCII, as defined above, therefore is the same as G except that T is replaced by T", wherein T" is the same as T above except that, in R 6 , --Si(R 8 ) 3 replaces hydrogen. When R 1 in formula XCI is alkyl, then R 17 in formula XCII will also be alkyl. The necessary silylating agents for these transformations are known in the art or are prepared by methods known in the art. See, for example, Post, "Silicones and Other Organic Silicon Compounds," Reinhold Publishing Corp., New York, N.Y. (1949).
Referring again to Chart J, the intermediate silyl compounds of formula XCII are transformed to the final compounds of formulas XCIII and XCIV by first reacting the silyl compound with a Grignard reagent of the formula R 16 MgHal wherein R 16 is as defined above, and Hal is chloro, bromo, or iodo. For this purpose, it is preferred that Hal be bromo. This reaction is carried out by the usual procedure for Grignard reactions, using diethyl ether as a reaction solvent and saturated aqueous ammonium chloride solution to hydrolyze the Grignard complex. The resulting disilyl, trisilyl, or tetrasilyl tertiary alcohol is then hydrolyzed with water to remove the silyl groups. For this purpose, it is advantageous to use a mixture of water and sufficient of a water-miscible solvent, e.g., ethanol to give a homogenous reaction mixture. The hydrolysis is usually complete in 2 to 6 hours at 25° C., and is preferably carried out in an atmosphere of an inert gas, e.g., nitrogen or argon.
The mixture of 15-α and 15-β isomers obtained by this Grignard reaction and hydrolysis is separated by procedures known in the art for separating mixtures of prostanoic acid derivatives, for example, by chromatography on neutral silica gel. In some instances, the lower alkyl esters, especially the methyl esters of a pair of 15-α and 15-β isomers are more readily separated by silica gel chromatography than are the corresponding acids. In those cases, it is advantageous to esterify the mixture of acids as described below, separate the two esters, and then, if desired, saponify the esters by procedures known in the art for saponification of prostaglandins F.
Although formula-XCIII and -XCIV compounds wherein E' is --CH 2 CHR 9 --and J' is L' as defined above may be produced according to the processes of Chart J, it is preferred to produce those novel dihydro-PGF 1 analogs by hydrogenation of one of the corresponding unsaturated compounds, i.e., a compound of formula XCIII or XCIV wherein E is trans --CH=CR 9 --and J' is either L', --CH=CH--M'--, --C.tbd.C--M'-, M' being defined above. This hydrogenation is advantageously carried out catalytically, for example, in the presence of a 5% palladium-on-charcoal catalyst in ethyl acetate solution at 25° C. and one atmosphere pressure of hydrogen.
The novel 15-alkyl oxa-phenylene PGA-type and PGB-type acids and esters of formula XXIV-XXXI and XXXIV-XXXV are prepared from the 15-alkyl oxa-phenylene PGE compounds, heretofore described, by dehydrations and double bond migrations previously described, as shown in Chart A. Likewise the 15-alkyl PGB-type compounds are prepared by contacting the 15-alkyl PGA-type compounds with base. For the transformation of the 15-alkyl PGE-type compounds to the 15-alkyl PGA-type compounds of this invention (Chart K), it is preferred that a dehydrating agent be used which removes ##SPC84##
the hydroxy group from the alicyclic ring in the presence of a hydroxy group on a tertiary carbon atom. In Chart K, E', G, J', R 1 , R 2 , R 26 , and ˜ are as defined above. Formula XCV as shown includes optically active compounds and racemic compounds of that formula and the mirror images thereof, and also the 15-epimers of both of those. Any of the known substantially neutral dehydrating agents is used for these reactions. See Fieser et al., cited above. Preferred dehydrating agents are mixtures of at least an equivalent amount of a carbodiimide and a catalytic amount of a copper (II) salt. Especially preferred are mixtures of at least an equivalent amount of dicyclohexyl carbodiimide and a catalytic amount of copper (II) chloride. An equivalent amount of a carbodiimide means one mole of the carbodiimide for each mole of the formula-XCV reactant. To ensure completeness of the reaction, it is advantageous to use an excess of carbodiimide, i.e., 1.5 to 5 or even more equivalents of the carbodiimide.
The dehydration is advantageously carried out in the presence of an inert organic diluent which gives a homogeneous reaction mixture with respect to the formula-XCV reactant and the carbodiimide. Diethyl ether is a suitable diluent. It is advantageous to carry out the dehydration in an atmosphere of an inert gas, e.g., nitrogen, helium, or argon. The time required for the dehydration will depend in part on the reaction temperature. With the reaction temperature in the range 20° to 30°C., the dehydration usually takes place in about 40 to 60 hours. The formula-XCVI product is isolated by methods known in the art, e.g., filtration of the reaction mixture and evaporation of the filtrate. The product is then purified by methods known in the art, advantageously by chromatography on silica gel.
The final formula XVI-to-XXXV compounds prepared by the processes of this invention, in free acid form, are transformed to pharmacologically acceptable salts by neutralization with appropriate amounts of the corresponding inorganic or organic base, examples of which correspond to the cations and amines listed above. These transformations are carried out by a variety of procedures known in the art to be generally useful for the preparation of inorganic, i.e., metal or ammonium, salts, amine acid addition salts, and quaternary ammonium salts. The choice of procedure depends in part upon the solubility characteristics of the particular salt to be prepared. In the case of the inorganic salts, it is usually suitable to dissolve the formula XVI-to-XXXV acid in water containing the stoichiometric amount of a hydroxide, carbonate, or bicarbonate corresponding to the inorganic salt desired. For example, such use of sodium hydroxide, sodium carbonate, or sodium bicarbonate gives a solution of the sodium salt. Evaporation of the water or addition of a water-miscible solvent of moderate polarity, for example, a lower alkanol or a lower alkanone, gives the solid inorganic salt if that form is desired.
To produce an amine salt, the formula XVI-to-XXXV acid is dissolved in a suitable solvent of either moderate or low polarity. Examples of the former are ethanol, acetone, and ethyl acetate. Examples of the latter are diethyl ether and benzene. At least a stoichiometric amount of the amine corresponding to the desired cation is then added to that solution. If the resulting salt does not precipitate, it is usually obtained in solid form by addition of a miscible diluent of low polarity or by evaporation. If the amine is relatively volatile, any excess can easily be removed by evaporation. It is preferred to use stoichiometric amounts of the less volatile amines.
Salts wherein the cation is quaternary ammonium are produced by mixing the formula XVI-to-XXXV acid with the stoichiometric amount of the corresponding quaternary ammonium hydroxide in water solution, followed by evaporation of the water.
The final formula XVI-to-XXXV acids or esters prepared by the processes of this invention are transformed to lower alkanoates by interaction of the formula XVI-to-XXXV hydroxy compound with a carboxyacylating agent, preferably the anhydride of a lower alkanoic acid, i.e., an alkanoic acid of one to 8 carbon atoms, inclusive. For example, use of acetic anhydride gives the corresponding diacetate. Similar use of propionic anhydride, isobutyric anhydride, and hexanoic acid anhydride gives the corresponding carboxyacylates.
The carboxyacylation is advantageously carried out by mixing the hydroxy compound and the acid anhydride, preferably in the presence of a tertiary amine such as pyridine or triethylamine. A substantial excess of the anhydride is used, preferably about 10 to about 10,000 moles of anhydride per mole of the hydroxy compound reactant. The excess anhydride serves as a reaction diluent and solvent. An inert inorganic diluent, for example, dioxane, can also be added. It is preferred to use enough of the tertiary amine to neutralize the carboxylic acid produced by the reaction, as well as any free carboxyl groups present in the hydroxy compound reactant.
The carboxyacylation reaction is preferably carried out in the range about 0° to about 100° C. The necessary reaction time will depend on such factors as the reaction temperature, and the nature of the anhydride and tertiary amine reactants. With acetic anhydride, pyridine, and a 25° C. reaction temperature, a 12 to 24-hour reaction time is used.
The carboxyacylated product is isolated from the reaction mixture by conventional methods. For example, the excess anhydride is decomposed with water, and the resulting mixture acidified and then extracted with a solvent such as diethyl ether. The desired carboxyacylate is recovered from the diethyl ether extract by evaporation. The carboxyacylate is then purified by conventional methods, advantageously by chromatography.
By this procedure, the formula XVI-XIX and XXXII PGE-type compounds are transformed to dialkanoates, the formula XX-XXIII and XXXIII PGF-type compounds are transformed to trialkanoates, and the formula XXIV-XXXI and XXXIV-XXXV PGA-type and PGB-type compounds are transformed to monoalkanoates.
When a PGE-type dialkanoate is transformed to a PGF-type compound by carbonyl reduction as shown in Chart A, a PGF-type dialkanoate is formed and is used for the above-described purposes as such or is transformed to a trialkanoate by the above-described procedure. In the latter case, the third alkanoyloxy group can be the same as or different from the two alkanoyloxy groups present before the carbonyl reduction.
Molecules of each of the compounds encompassed by formulas XVI to XXXV and, except for XLIII and L, of each intermediate formula each have at least one center of asymmetry, and each can exist in racemic form and in either enantiomeric form, i.e., d and l. A formula accurately defining the d form would be the mirror image of the formula which defined the l form. Both formulas are necessary to define accurately the corresponding racemic form. The various formulas XVI-to-XXXV as drawn each represents the optically active form with the same configuration as the naturally-occurring prostaglandins.
When an optically active (d or l) final compound is desired, that is made by resolution of the racemic compound or by resolution of one of the asymmetric racemic intermediates. These resolutions are carried out by procedures known in the art. For example, when final compound XVI to XXXV is a free acid, the dl form thereof is resolved into the d and l forms by reacting said free acid by known general procedures with an optically active base, e.g., brucine or strychnine, to give a mixture of two diastereoisomers which are separated by known general procedures, e.g., fractional crystallization, to give the separate diastereiosomeric salts. The optically active acid of formula XVI to XXXV is then obtained by treatment of the salt with an acid by known general procedures. Alternatively, the free acid form of cyclic ketal XXXVII, olefins XLIV or LXX, or glycols XXXVIII, XLV, or LXXI is resolved into separate d and l forms and then esterified and transformed further to the corresponding optically active form of the final product XVI to XXXV as described above.
In another method, bicyclo ketone reactants XXXVIII, XLV, or LXXI in exo or endo form, are transformed to ketals with an optically active 1,2-glycol, e.g., D-(--)-2,3-butanediol, by reaction of said 1,2-glycol with the formula-XXXVIII, XLV, or LXXI compound in the presence of a strong acid, e.g., p-toluenesulfonic acid. The resulting ketal is a mixture of diastereoisomers which is separated into the d and l diastereoisomers, each of which is then hydrolyzed with an acid, e.g., oxalic acid, to the original keto compound, now in optically active form. These reactions involving optically active glycols and ketals for resolution purposes are generally known in the art. See, for example, Chem. Ind. 1664 (1961) and J. Am. Chem. Soc. 84, 2938 (1962). Dithiols may be used instead of glycols.
Still another procedure for obtaining optically active oxa-phenylene PGF-type compounds is by stereoselective microbiological reduction of the racemic oxa-phenylene PGE compounds. For this purpose actively fermenting baker's yeast is employed. The PGE compound is contacted with a yeast-sugar-water mixture at about 25° C. for 24-48 hours. There is produced by reduction a mixture of the PGF.sub.α compound and the enantiomeric PGF.sub.β compound, which are separable by silica gel chromatography for example. Accompanying this transformation, carboxylic ester groups are removed by hydrolysis. Accordingly, from dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 methyl ester, there are obtained natural configuration 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α and enantiomeric 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.β.
An alternate method of synthesis is provided hereinafter for a group of oxa-phenylene analogs within the scope of formulas XVI and XX above, represented by the following formulas XCVII-CIV; ##SPC85##
and the racemic mixtures of those compounds and their respective enantiomers represented by the mirror images of the above formulas. The terms C p H 2p , C t H 2t , R 1 , R 2 , T, and s are as defined above; R 30 is alkyl of 2 to 10 carbon atoms, inclusive, substituted with zero, one, 2, or 3 fluoro.
The alternate method of synthesis disclosed hereinafter is also useful for preparing oxa-phenylene 17,18-didehydro prostaglandin analogs within the scope of formulas CV-CVIII: ##SPC86##
wherein C n H 2n , C p H 2p , R 1 , R 2 , and R 5 are as defined and used above.
These 17,18-didehydro analogs of formulas CV-CVIII together with compounds of formulas XXXII and XXXIII above are within the scope of 17,18-didehydro PGE- and PGF-type compounds represented by the formulas: ##SPC87##
wherein ˜ indicates attachment of the hydroxyl or the side chain to the cyclopentane ring in alpha or beta configuration; wherein V is (1) C g H 2g or (2) --CH=CH-- C j H 2j --, wherein C g H 2g represents a valence bond or alkylene of one to 4 carbon atoms, inclusive, with one or 2 chain carbon atoms between --CH 2 -- and the phenylene ring, and wherein C j H 2j represents a valence bond or alkylene of one or 2 carbon atoms with one chain carbon atom between --CH=CH-- and the phenylene ring; wherein C n H 2n is alkylene of one to 4 carbon atoms, inclusive; wherein C p H 2p represents a valence bond or alkylene of one to 4 carbon atoms, inclusive, with one or 2 chain carbon atoms between the ring and --O--; wherein C g H 2g and C p H 2p together represent zero to 8 carbon atoms, inclusive, with total chain lengths zero to 3 carbon atoms, inclusive; wherein Q is ##EQU41## wherein R 2 is hydrogen or alkyl of one to 4 carbon atoms, inclusive; wherein R 1 is hydrogen, alkyl of one to 12 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, phenyl substituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive; and wherein R 5 is alkyl of one to 4 carbon atoms, inclusive, substituted with zero, one, 2, or 3 fluoro.
The corresponding 17,18-didehydro PGA- and PGB-type compounds are available by methods disclosed herein or known in the art, for example by acid or base dehydration of the formula-CXXXVII PGE-type compounds.
The alternate method of synthesis utilizes oxetane intermediates having the grouping ##SPC88##
prepared from bicyclo hexene starting materials.
Reference to Chart L will make clear the steps by which starting material CIX is transformed to product CXVIII. The formula-CIX compound wherein R 31 and R 32 together are --CH 2 --C(CH 3 ) 2 --CH 2 -- and ˜ is endo, i.e. bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde neopentyl glycol acetal, is available either in racemic or optically active form. See U.S. Pat. No. 3,711,515.
In Chart L the symbols used therein have the same meanings as defined above, as to C p H 2p , G, Q, R 1 , R 2 , R 31 , R 32 , R 39 , R 42 , and ˜. R 43 represents hydrogen, carboxyacyl R 39 , benzoyl, substituted benzoyl, mono-esterified phthaloyl, and substituted naphthoyl. Furthermore, in Chart L and likewise in the other charts of this specification, the formulas as drawn represent specific optical isomers following the conventions applied herein to the end products. However, for purposes of convenience and brevity it is intended that such representations of the process steps for the optically active intermediates are applicable to those same process steps as used for the corresponding racemic intermediates.
Both the endo and exo forms of bicyclo hexene CIX are available or are made by methods known in the art, in either their racemic or optically active forms. See. U.S. Pat. No. 3,711,515. ##SPC89##
Either the endo or exo starting material will yield the ultimate analogs of formula CXVIII by the processes of Chart L.
In step (a) oxetane CX is obtained by reaction of the formula-CIX bicyclo hexene with an aldehyde of the formula ##SPC90##
wherein C p H 2p represents a valence bond or alkylene of one to 4 carbon atoms, inclusive, with one or 2 carbon atoms in the chain between the phenylene ring and --O--, and wherein R 39 is carboxyacyl of the formula ##EQU42## wherein R 40 is hydrogen, alkyl of one to 19 carbon atoms, inclusive, or aralkyl of 7 to 12 carbon atoms, inclusive, wherein alkyl or aralkyl are substituted with zero to 3 halo atoms.
The formula-CXIX aldehydes are available or readily prepared by methods known in the art. Examples of such compounds within the scope of formula CXIX are: ##SPC91##
The formation of oxetane CX is accomplished by photolysis of a mixture of the bicyclo hexene and the aldehyde in a solvent. The bicyclo hexene is preferably used in excess over the molar equivalent, for example 2 to 4 times the theoretical equivalent amount. The solvent is a photochemically inert organic liquid, for example liquid hydrocarbons, including benzene or hexane, 1,4-dioxane, and diethyl ether. The reaction is conveniently done at ambient conditions, for example 25° C., but may be done over a wide range of temperature, from about -78° C. to the boiling point of the solvent. The irradiation is done with mercury vapor lamps of the low or medium pressure type, for example those peaking at 3500 A. Such sources are available from The Southern New England Ultraviolet Co., Middletown, Conn. Alternatively, those lamps which emit a broad spectrum of wavelengths and which may be filtered to transmit only light of λ˜3000-3700 A may also be used. For a review of photolysis see D. R. Arnold in "Advances in Photochemistry," Vol. 6, W. A. Noyes et al., Wiley-Interscience, New York, 1968, pp. 301-423.
In step (b) the cleavage of the oxetane ring to yield the formula-CXI compounds is accomplished with an alkali metal in the presence of a primary amine or alcohol. Preferred is lithium in ethylamine, or sodium in ethyl alcohol. See L. J. Altman et al., Synthesis 129 (1974). The cleavage transformation may also be accomplished by catalytic hydrogenation over an inert metal catalyst, e.g. Pd on carbon, in ethyl acetate or ethanol.
In step (c) the formula CXI diol is prepared for step (d) by preferably blocking the two hydroxyl groups with carboxyacyl groups within the scope of R 39 , i.e. ##EQU43## as defined above. For example, the diol is treated with an acid anhydride such as acetic anhydride, or with an acyl halide in a tertiary amine. Expecially preferred is pivaloyl chloride in pyridine.
Other carboxyacylating agents useful for this transformation are known in the art or readily obtainable by methods known in the art, and include carboxyacyl halides, preferably chlorides, bromides, or fluorides, i.e. R 40 C(O)Cl, R 40 C(O)Br, or R 40 C(O)F, and carboxyacid anhydrides, (R 40 C--) 2 O, wherein R 40 is as defined above. The preferred reagent is an acid anhydride. Examples of acid anhydrides useful for this purpose are acetic anhydride, propionic anhydride, butyric anhydride, pentanoic anhydride, nonanoic anhydride, trideconoic anhydride, steric anhydride, (mono, di or tri) chloroacetic anhydride, 3-chlorovaleric anhydride, 3-(2-bromoethyl)-4,8-dimethylnonanoic anhydride, cyclopropaneacetic anhydride, 3-cycloheptanepropionic anhydride, 13-cyclopentanetridecanoic anhydride, phenylacetic anhydride, (2 or 3)-phenylpropionic anhydride, 13-phenyltridecanoic anhydride, phenoxyacetic anhydride, benzoic anhydride, (o, m, or p)-bromobenzoic anhydride, 2,4 (or 3,4)-dichlorobenzoic anhydride, p-trifluoromethylbenzoic anhydride, 2-chloro-3-nitrobenzoic anhydride, (o, m, or p)-nitrobenzoic anhydride, (o, m, or p)-toluic anhydride, 4-methyl-3-nitrobenzoic anhydride, 4-octylbenzoic anhydride, (2,3, or 4)-biphenylcarboxylic anhydride, 3-chloro-4-biphenylcarboxylic anhydride, 5-isopropyl-6-nitro-3-biphenylcarboxylic anhydride, and (1 or 2)-naphthoic anhydride. The choice of anhydride depends upon the identity of R 40 in the final acylated product, for example when R 40 is to be methyl, acetic anhydride is used; when R 40 is to be 2-chlorobutyl, 3-chlorovaleric anhydride is used.
When R 40 is hydrogen, ##EQU44## is formyl. Formylation is carried out by procedures known in the art, for example, by reaction of the hydroxy compound with the mixed anhydride of acetic and formic acids or with formylimidazole. See, for example, Fieser et al., Reagents for Organic Synthesis, John Wiley and Sons, Inc., pp. 4 and 407 (1967) and references cited therein. Alternatively, the formula CXI diol is reacted with two equivalents of sodium hydride and then with excess ethyl formate.
In formula CXII, R 43 may also represent a blocking group including benzoyl, substituted benzoyl, monoesterified phthaloyl and substituted naphthoyl. For introducing those blocking groups, methods known in the art are used. Thus, an aromatic acid of the formula R 39 OH, wherein R 39 is as defined above, for example benzoic acid, is reacted with the formula-CXI compound in the presence of a dehydrating agent, e.g. sulfuric acid, zinc chloride, or phosphoryl chloride; or an anhydride of the aromatic acid of the formula (R 39 ) 2 O, for example benzoic anhydride, is used.
Preferably, however, an acyl halide, e.g. R 39 Cl, for example benzoyl chloride, is reacted with the formula-CXI compound in the presence of a tertiary amine such as pyridine, triethylamine, and the like. The reaction is carried out under a variety of conditions using procedures generally known in the art. Generally, mild conditions are employed, e.g. 20°-60° C., contacting the reactants in a liquid medium, e.g. excess pyridine or an inert solvent such as benzene, toluene or chloroform. The acylating agent is used either in stoichiometric amount or in excess.
As examples of reagents providing R 39 for the purposes of this invention, the following are available as acids (R 39 OH), anhydrides ((R 39 ) 2 O), or acyl chlorides (R 39 Cl): benzoyl; substituted benzoyl, e.g. (2-, 3-, or 4-)methylbenzoyl, (2-, 3-, or 4-)ethylbenzoyl, (2-, 3-, or 4-)isopropylbenzoyl, (2-, 3-, or 4-)tert-butylbenzoyl, 2,4-dimethylbenzoyl, 3,5-dimethylbenzoyl, 2-isopropyltoluyl, 2,4,6-trimethylbenzoyl, pentamethylbenzoyl, α-phenyl-(2-, 3-, or 4-(toluyl, 2-, 3-, or 4-phenethylbenzoyl, 2-, 3-, or 4-nitrobenzoyl, (2,4-, 2,5-, or 3,5-)dinitrobenzoyl, 4,5-dimethyl-2-nitrobenzoyl, 2-nitro-6-phenethylbenzoyl, 3-nitro-2-phenethylbenzoyl; mono-esterified phthaloyl, e.g. ##SPC92##
isophthaloyl, e.g. ##SPC93##
or terephthaloyl, e.g. ##SPC94##
(1- or 2-)naphthoyl; and substituted naphthoyl, e.g. (2-, 3-, 4-, 5-, 6-, or 7-)-methyl-1-naphthoyl, (2-or 4-)ethyl-1-naphthoyl, 2-isopropyl-1-naphthoyl, 4,5-dimethyl-1-naphthoyl, 6-isopropyl-4-methyl-1-naphthoyl, 8-benzyl-1-naphthoyl, 8-benzyl-1-naphthoyl, (3-, 4-, 5-, or 8-)-nitro-1-naphthoyl, 4,5-dinitro-1-naphthoyl, (3-, 4-, 6-, 7- or 8)-methyl-1-naphthoyl, 4-ethyl-2-naphthoyl, and (5- or 8-)-nitro-2-naphthoyl. There may be employed, therefore, benzoyl chloride, 4-nitrobenzoyl chloride, 3,5-dinitrobenzoyl chloride, and the like, i.e. R 39 Cl compounds corresponding to the above R 39 groups. If the acyl chloride is not available, it is made from the corresponding acid and phosphorus pentachloride as is known in the art.
In step (d), the formula -CXII acetal is converted to aldehyde CXIII by acid hydrolysis, known in the art, using dilute mineral acids, acetic or formic acids, and the like. Solvents such as acetone, dioxane, and tetrahydrofuran are used.
For steps (e) through (h) it is optional whether R 42 be hydrogen or a "blocking group" as defined below. For efficient utilization of the Wittig reagent it is preferred that R 42 be a blocking group. If the formula-CXII compound is used wherein R 43 is hydrogen, the formula-CXIII intermediates will have hydrogen at R 42 . If R 42 is to be a blocking group, that may be readily provided prior to step (e) by reaction with suitable reagents as discussed below.
The blocking group, R 41 , is any group which replaces hydrogen of the hydroxyl groups, which is not attacked by nor is reactive to the reagents used in the respective transformations to the extent that the hydroxyl group is, and which is subsequently replaceable by hydrogen at a later stage in the preparation of the prostaglandin-like products.
Several blocking groups are known in the art, e.g. tetrahydropyranyl, acetyl, and p-phenylbenzoyl (see Corey et al., J. Am. Chem. Soc. 93, 1491 (1971)).
Those which have been found useful include (a) carboxyacyl within the scope of R 39 above, i.e. acetyl, and also benzoyl, naphthoyl, and the like; (b) tetrahydropyranyl; (c) tetrahydrofuranyl; (d) a group of the formula ##EQU45## wherein R 48 is alkyl of one to 18 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl substituted with one, 2, or 3 alkyl of one to 4 carbon atoms, inclusive, wherein R 49 and R 50 are the same or different, being hydrogen, alkyl of one to 4 carbon atoms, inclusive, phenyl or phenyl substituted with one, 2, or 3 alkyl of one to 4 carbon atoms, inclusive, or, when R 49 and R 30 are taken together, --(CH 2 ) u -- or --(CH 2 ) v --O--(CH 2 ) w --wherein u is 3, 4, or 5, v is one, 2, or 3, and w is one, 2, or 3 with the proviso that v plus w is 2, 3, or 4, and wherein R 51 is hydrogen or phenyl; or (e) --Si(A) 3 wherein A is alkyl of one to four carbon atoms, inclusive, phenyl, phenyl substituted with one or 2 fluoro, chloro, or alkyl of one to four carbon atoms, inclusive, or aralkyl of 7 to 12 carbon atoms, inclusive.
In replacing the hydrogen atoms of the hydroxyl groups with a carboxyacyl blocking group, methods known in the art are used. The reagents and conditions are discussed above for R 43 on compound CXII.
When the blocking group is tetrahydropyranyl or tetrahydrofuranyl, the appropriate reagent, e.g. 2,3-dihydropyran or 2,3-dihydrofuran, is used in an inert solvent such as dichloromethane, in the presence of an acid condensing agent such as p-toluenesulfonic acid or pyridine hydrochloride. The reagent is used in slight excess, preferably 1.0 to 1.2 times theory. The reaction is carried out at about 20°-50° C.
When the blocking group is of the formula ##EQU46## as defined above, the appropriate reagent is a vinyl ether, e.g. isobutyl vinyl ether or any vinyl ether of the formula R 48 --O--C(R 49 )=CR 50 R 51 wherein R 48 , R 49 , R 50 , and R 51 are as defined above; or an unsaturated cyclic or heterocyclic compound, e.g. 1-cyclohex-1-yl methyl ether ##SPC95##
or 5,6-dihydro-4-methoxy-2H-pyran ##SPC96##
See C. B. Reese et al., J. Am. Chem. Soc. 89, 3366 (1967). The reaction conditions for such vinyl ethers and unsaturates are similar to those for dihydropyran above.
When the blocking group is silyl of the formula --Si(A) 3 , the formula-CXIII compound is transformed to a silyl derivative of formula CXIII by procedures known in the art. See, for example, Pierce, "Silylation or Organic Compounds," Pierce Chemical Co., Rockford, Ill. (1968). The necessary silylating agents for these transformations are known in the art or are prepared by methods known in the art. See, for example, Post "Silicones and Other Organic Silicon Compounds," Reinhold Publishing Corp., New York, N.Y. (1949). These reagents are used in the presence of a tertiary base such as pyridine at temperatures in the range of about 0° to +50° C. Examples of trisubstituted mono-chlorosilanes suitable for this purpose include chlorotrimethylsilane, chlorotriisobutylsilane, chlorotriphenylsilane, chlorotris(p-chlorophenyl)silane, chlorotri-m-tolylsilane, and tribenzylchlorosilane. Alternately, a chlorosilane is used with a corresponding disilazane. Examples of other silylating agents suitable for forming the formula-CXIII intermediates include pentamethylsilylamine, pentaethylsilylamine, N-trimethylsilydiethylamine, 1,1,1-triethyl-N,N-dimethylsilylamine, N,N-diisopropyl-1,1,1,-trimethylsilylamine, 1,1,1-tributyl-N,N-dimethylsilylamine N,N-dibutyl-1,1,1-trimethylsilylamine, 1-isobutyl-N,N,1,1-tetramethylsilylamine, N-benzyl-N-ethyl-1,1,1-trimethylsilylamine, N,N,1,1-tetramethyl-1-phenylsilylamine, N,N-diethyl-1,1-dimethyl-1-phenylsilylamine, N,N-diethyl-1-methyl-1,1-diphenylsilylamine, N,N-dibutyl-1,1,1-triphenylsilylamine, and 1-methyl-N,N,1,1-tetraphenylsilylamine.
In step (e) the aldehyde group is transformed by the Wittig reaction to a moiety of the formula --CH=CR 2 G. For this purpose a phosphonium salt prepared from an organic chloride or bromide of the formula ##EQU47## is employed, wherein G and R 2 are as defined above. These organic chlorides or bromides are known in the art or are readily prepared by methods known in the art. See for example the above-identified German Offenlegungsschrift No. 2,209,990. As to the Wittig reaction, see, for example, U.S. Pat. No. 3,776,941 and references cited therein.
In step (f) compound CXV is obtained by deblocking if necessary. When C p H 2p is a valence bond, and R 42 is a hindered carboxyacyl, e.g. ##EQU48## R 41 on the phenolic hydroxy is selectively replaced with hydrogen by hydrolysis with sodium or potassium hydroxide in ethanol-water. Instead of ethanol, other water-miscible solvents may be substituted, for example 1,4-dioxane, tetrahydrofuran, or 1,2-dimethoxyethane. The selective hydrolysis is preferably carried out at -15° to 25° C. Higher temperatures may be used but with some decrease in selectivity.
Total hydrolysis of R 42 blocking groups on compound CXIV is accomplished, when R 42 is carboxyacyl, with an alkali alkoxide in an alcoholic solvent, preferably sodium methoxide in methanol at a temperature from 25° C. to reflux. When R 42 is tetrahydropyranyl, aqueous acid, e.g. dilute acetic acid, is used at 25° to 50° C. When R 42 is trialkylsilyl, either aqueous acid or base are used at 25° to 50° C.
Continuing with Chart L, in step (g) a Williamson synthesis is employed to obtain compound CXVI. The formula-CXV alcohol or phenol is condensed with a haloacetate within the scope of Hal--CH 2 --COOR 1 wherein Hal is chloro, bromo, or iodo and R 1 is as defined above. Normally the reaction is done in the presence of a base such as n-butyllithium, phenyllithium, triphenylmethyllithium, sodium hydride, potassium t-butoxide, sodium hydroxide, or potassium hydroxide.
The transformation from compound CXVI to product CXVIII may be accomplished by any of several routes known in the art. See U.S. Pat. No. 3,711,515. Thus, by step (h), the alkenene CXVI is hydroxylated to glycol CXVII. For this purpose osmium tetroxide is a suitable reagent, for example in conjunction with N-methylmorpholine oxide-hydrogen peroxide complex (see Fieser et al., "Reagents for Organic Synthesis," p. 690, John Wiley and Sons, Inc., New York (1967)). Thereafter, several methods are available for obtaining the formula-CXVIII product. In one method the glycol is converted to a bis(alkanesulfonic acid) ester and subsequently hydrolyzed to CXVIII by methods known in the art (see, for example German Offenlegungsschrift No. 1,937,676, Derwent Farmdoc No. 6862R). Another method is by way of a diformate by formolysis of the glycol (see U.S. Pat. No. 3,711,515).
Still another method is by way of a cyclic ortho ester. For this purpose, glycol CXVII is reacted with an ortho ester of the formula ##EQU49## wherein R 46 is hydrogen, alkyl of one to 19 carbon atoms, inclusive, or aralkyl of 7 to 12 carbon atoms, inclusive, substituted with zero to 3 halo atoms; and R 47 is methyl or ethyl. There is then formed a cyclic ortho ester of the formula ##SPC97##
wherein C p H 2p , G, R 1 , R 2 R 42 , R 46 , R 47 , and ˜ are as defined above. The reaction goes smoothly in a temperature range of -50° C. to +100° C., although for convenience 0° C. to +50° C. is generally preferred. From 1.5 to 10 molar equivalents of the ortho ester are employed, together with an acid catalyst. The amount of the catalyst is usually a small fraction of the weight of the glycol, say 1%, and typical catalysts include pyridine hydrochloride, formic acid, hydrogen chloride, p-toluenesulfonic acid, trichloroacetic acid, or trifluoroacetic acid. The reaction is preferably run in a solvent, for example benzene, dichloromethane, ethyl acetate, or diethyl ether. It is generally completed within a few minutes and is conveniently followed by TLC (thin layer chromatography on basic silica gel plates).
The ortho ester reagents are known in the art or readily available by methods known in the art. See for example S. M. McElvain et al., J. Am. Chem. Soc. 64, 1925 (1942), starting with an appropriate nitrile. Examples of useful ortho esters include:
trimethyl orthoformate,
triethyl orthoacetate,
triethyl orthopropionate,
trimethyl orthobutyrate,
triethyl orthovalerate,
trimethyl orthooctanoate,
trimethyl orthophenylacetate, and
trimethyl ortho (2,4-dichlorophenyl)acetate.
Preferred are those ortho esters wherein R 46 is alkyl of one to 7 carbon atoms; especially preferred are those wherein R 46 is alkyl of one to 4.
Next, the cyclic orthoester CXX is reacted with anhydrous formic acid to yield a diol diesters of the formula ##SPC98##
wherein C p H 2p , G, R 1 R 2 , R 42 , R 46 , and ˜ are as defined above.
By "anhydrous formic acid" is meant that it contains not more than 0.5% water. The reaction is run with an excess of formic acid, which may itself serve as the solvent for the reaction. Solvents may be present, for example dichloromethane, benzene, or diethyl ether, usually not over 20% by volume of the formic acid. There may also be present organic acid anhydrides, for example acetic anhydride, or alkyl orthoesters, for example trimethyl orthoformate, which are useful as drying agents for the formic acid. Although the reaction proceeds over a wide range of temperatures, it is conveniently run at about 20°-30° C. and is usually completed within about 10 minutes.
Finally, the diol diester CXXI is converted to product CXVIII by methods known in the art, for example by hydrolysis in the presence of a base in an alcoholic medium. Examples of the base are sodium or potassium carbonate or sodium or potassium alkoxides including methoxides or ethoxides. The reaction is conveniently run in an excess of the solvolysis reagent, for example methanol or ethanol. The temperature range is from -50° C. to 100° C. The time for completion of the reaction varies with the nature of R 46 and the base, proceeding in the case of alkali carbonates in a few minutes when R 46 is hydrogen but taking up to several hours when R 46 is ethyl, for example.
When the solvolysis proceeds too long or when conditions are too severe, ester groups at R 1 may be removed. They are, however, readily replaced by methods known in the art. For example, the alkyl, cycloalkyl, and aralkyl esters are prepared by interaction of the formula-CXVIII acids with the appropriate diazohydrocarbon. For example, when diazomethane is used, the methyl esters are produced. Similar use of diazoethane, diazobutane, 1-diazo-2-ethylhexane, diazocyclohexane, and phenyldiazomethane, for example, gives the ethyl, butyl, 2-ethylhexyl, cyclohexyl, and benzyl esters, respectively.
Esterification with diazohydrocarbons is carried out by mixing a solution of the diazohydrocarbon in a suitable inert solvent, preferably diethyl ether, with the acid reactant, advantageously in the same or a different inert diluent. After the esterification reaction is complete, the solvent is removed by evaporation, and the ester purified if desired by conventional methods, preferably by chromatography. It is preferred that contact of the acid reactants with the diazohydrocarbon be no longer than necessary to effect the desired esterification, preferably about one to about ten minutes, to avoid undesired molecular changes. Diazohydrocarbons are known in the art or can be prepared by methods known in the art. See, for example Organic Reactions, John Wiley & Sons, Inc., New York, N.Y. Vol. 8, pp. 389-394 (1954).
An alternative method for esterification of the carboxyl moiety comprises transformation of the free acid to the corresponding silver salt, followed by interaction of that salt with an alkyl iodide. Examples of suitable iodides are methyl iodide, ethyl iodide, butyl iodide, isobutyl iodide, tere-butyl iodide, cyclopropyl iodide, cyclopentyl iodide, benzyl iodide, phenethyl iodide, and the like. The silver salts are prepared by conventional methods, for example, by dissolving the acid in cold dilute aqueous ammonia, evaporating the excess ammonia at reduced pressure, and then adding the stoichiometric amount of silver nitrate.
The phenyl and substituted phenyl esters are prepared by silylating the acid to protect the hydroxy groups, for example, replacing each --OH with --O--Si--(CH 3 ) 3 . Doing that may also change --COOH to --COO--Si--(CH 3 ) 3 . A brief treatment of the silylated compound with water will change --COO--Si--(CH 3 ) 3 back to --COOH. Procedures for this silylation are known in the art. Then, treatment of the silylated compound with oxalyl chloride gives the acid chloride which is reacted with phenol or the appropriate substituted phenol to give a silylated phenyl or substituted phenyl ester. Then the silyl groups, e.g., --O--Si--(CH 3 ) 3 are changed back to --OH by treatment with dilute acetic acid. Procedures for these transformations are known in the art.
Referring to Chart M, there are shown process steps by which the formula-CIX bicyclo hexene is transformed first to an oxetane CXXII with a fully developed side chain. ##SPC99## ##SPC100##
and ultimately to a PGE analog. In Chart M, R 44 is hydrogen or alkyl of one to 4 carbon atoms, inclusive, and R 45 is hydrogen, alkyl of one to 4 carbon atoms, inclusive, or silyl of the formula (A) 3 Si-- wherein A is as defined herein above.
In step (a) of Chart M, there is employed an aldehyde of the formula ##SPC101##
wherein C p H 2p and R 44 are as defined above. Such aldehydes are available or readily prepared by methods known in the art. Examples of such compounds include: ##SPC102##
The conditions for step (a) of Chart M are essentially the same as for step (a) of Chart L. Thereafter, step (b) for cleavage of the oxetane ring, steps (c) and (d) leading to the formula-CXXV aldehyde, and the Wittig reaction of step (e) are similar to and employ the same conditions as the corresponding steps of Chart L discussed above.
Referring to step (g) of Chart M, the hydroxyl on the cyclopentane ring at the C-9 position is oxidized to an oxo group.
Oxidation reagents useful for this transformation are known in the art. A useful reagent for this purpose is the Jones reagent, i.e., acidified chromic acid. See J. Chem. Soc. 39 (1946). A slight excess beyond the amount necessary to oxidize the C-9 secondary hydroxy groups of the formula-CXXVII reactant is used. Acetone is a suitable diluent for this purpose. Reaction temperatures at least as low as about 0° C. should be used. Preferred reaction temperatures are in the range 0° to -50° C. An especially useful reagent for this purpose is the Collins reagent, i.e. chromium trioxide in pyridine. See J. C. Collins et al., Tetrahedron Lett., 3363 (1968). Dichloromethane is a suitable diluent for this purpose. Reaction temperatures of below 30° C. should be used. Preferred reaction temperatures are in the range 0° to +30° C. The oxidation proceeds rapidly and is usually complete in about 5 to 20 minutes.
Examples of other oxidation reagents useful for this transformation are silver carbonate on Celite (Chem. Commun. 1102 (1969)), mixtures of chromium trioxide and pyridine (J. Am. Chem. Soc. 75, 422 (1953), and Tetrahedron, 18, 1351 (1962)), t-butylchromate in pyridine (Biochem. J. 84, 195 (1962)), mixtures of sulfur trioxide in pyridine and dimethylsulfoxide (J. Am. Chem. Soc. 89, 5505 (1967)), and mixtures of dicyclohexylcarbodiimide and dimethyl sulfoxide (J. Am. Chem. Soc. 87, 5661 (1965)).
Step (h) of Chart M and subsequent steps by which the product CXXX is obtained are similar to and employ the same conditions as the corresponding steps of Chart L discussed above.
Referring next to Chart N the process steps are shown whereby aldehyde CXIII of Chart L is transformed to a 17,18-tetradehydro-PG analog CXXXVI and a 17,18-didehydro-PG analog CXXXVII.
In step (a) of Chart N, a Wittig reagent is employed which is prepared from a phosphonium salt of a haloalkyne of the formula
Cl--CHR.sub.2 --C.sub.n H.sub.2n --C.tbd.C--R.sub.5
or
Br--CHR.sub.2 --C.sub.n H.sub.2n --C.tbd.C--R.sub.5
wherein C n H 2n , R 2 , and R 5 are as defined above. See, for example, U. Axen et al., Chem. Comm. 1969, 303, and ibid. 1970, 602.
Thereafter, in steps (b) to (d) and subsequent steps yielding the 17,18-tetradehydro compound CXXVI, the reagents ##SPC103##
and conditions are similar to those employed for the corresponding reactions shown in Chart L.
Transformation of CXXXVI to the formula-CXXXVII compounds is accomplished by hydrogenation of CXXXVI using a catalyst which catalyzes hydrogenation of --C.tbd.C-- only to cis--CH=CH--, as known in the art. See, for example, Fieser et al., "Reagents for Organic Syntheses," pp. 566-567, John Wiley and Sons, Inc., New York (1967). Preferred is Lindlar catalyst in the presence of quinoline, see Axen, references cited.
The intermediates of Charts L, M, and N, including those compounds represented by formulas CX, CXI, CXII, CXIII, CXIV, CXV, CXVI, CXVII, CXXII, CXXIII, CXXIV, CXXV, CXXVI, CXXVII, CXXVIII, CXXIX, CXXXII, CXXXIII, CXXXIV, CXXXV, and CXXXVI are frequently not isolated but used directly for a subsequent process step. When they are isolated, they are purified by methods known in the art, for example partition extraction, fractional crystallization, and, preferably, silica gel column chromatography.
The products represented by formulas CXVIII, CXXX, and CXXXVII obtained from these intermediates are often a mixture of 15-α and 15-β isomers. These are separated by methods known in the art, for example, by chromatography on neutral silica gel. In some instances, particularly where R 2 is alkyl, the lower alkyl esters are more readily separated than are the corresponding acids. In those cases wherein R 1 is hydrogen, it is advantageous to esterify the mixture of acids, as with diazomethane, to form the methyl esters, separate the two epimers, and then, if desired, replace the carboxyl methyl with hydrogen by methods known in the art.
When an optically active intermediate or starting material is employed, subsequent steps yield optically active intermediates or products. That optical isomer of bicyclo hexene CIX is used which will yield product CXVIII for example, in the configuration corresponding to that of the naturally occurring prostaglandins. When the racemic form of the intermediate or starting material is employed, the subsequent intermediates or products are obtained in their racemic form.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention can be more fully understood by the following examples and preparations:
All temperatures are in degrees centigrade.
Infrared absorption spectra are recorded on a Perkin-Elmer Model 421 infrared spectrophotometer. Except when specified otherwise, undiluted (neat) samples are used.
Ultraviolet spectra are recorded on a Cary Model 15 spectrophotometer.
NMR spectra are recorded on a Varian A-60, A-60D, or T-60 spectrophotometer using deuterochloroform solutions with tetramethylsilane as an internal standard (downfield).
Mass spectra are recorded on a CEC Model 110B Double Focusing High Resolution Mass Spectrometer or an LKB Model 9,000 Gas Chromatograph-Mass Spectrometer (ionization voltage 70 ev).
Circular dichroism curves are recorded on a Cary 60 recording spectropolarimeter.
Specific rotations are determined for solutions of a compound in the specified solvent with a Perkin-Elmer Model 141 Automatic Polarimeter.
The collection of chromatographic eluate fractions starts when the eluant front reaches the bottom of the column.
"Brine," herein, refers to an aqueous saturated sodium chloride solution.
The A-IX solvent system used in thin layer chromatography is made up from ethyl acetate-acetic acid-2,2,4-trimethylpentane-water (90:20:50:100) according to M. Hamberg and B. Samuelsson, J. Biol. Chem. 241, 257 (1966).
"Skellysolve-B" refers to mixed isomeric hexanes.
Silica gel chromatography, as used herein, is understood to include elution, collection of fractions, and combination of those fractions shown by TLC (thin layer chromatography) to contain the desired product free of starting material and impurities.
PREPARATION 1
dl-Endo-6-(1-heptenyl)-3-(1-pyrrolidyl)-bicyclo[3.1.0]hex-2-ene.
A solution of formula-XLIII endo-6-(cis- and trans-1-heptenyl)bicyclo[3.1.0]hexan-3-one (see Example 29 of West Germany Offenlegungsschrift No. 1,937,912, cited above) (15 g.), 25 ml. of pyrrolidine, and 200 ml. of benzene is heated under reflux while removing the water formed by distillation. After 2 hrs. the benzene is replaced by 50 ml. of toluene which is then removed in vacuo to give the title compound. This material gives an infrared spectrum having absorption attributable to the enamine double bond at 1610 cm - 1 and free of carbonyl absorption.
PREPARATION 2
Methyl m-(Chloromethyl)phenoxyacetate (Formula LIII: C g H 2g and C p H 2p are valence bonds in meta relationship, C q H 2q is methylene, Hal is chloro, R 26 is hydrogen, and R 10 is methyl).
a. m-Formylphenoxyacetic Acid. To a solution of m-hydroxybenzaldehyde (48.8 g.) and sodium hydroxide (16.16 g.) in 500 ml. of water is added a solution prepared from chloroacetic acid (75 g.) and sodium hydroxide (32 g.) in 100 ml. of water. The mixture is heated under reflux for 2 hrs., cooled, and the pH is adjusted to pH 1 or 2. The mixture is extracted with dichloromethane-ether and the extract is dried and concentrated. The solid is taken up in saturated aqueous sodium bicarbonate, extracted with ether and the aqueous phase is made acidic. The aqueous phase is extracted with dichloromethane. The organic layer is concentrated and the residue is recrystallized from water to give m-formylphenoxyacetic acid (34.0 g.) m.p. 114°-117°.
b. Methyl M-Formylphenoxyacetate. A solution of the product of step a (30.0 g.) in 400 ml. of diethyl ethertetrahydrofuran is treated with an excess of ethereal diazomethane generated from N-methyl-N'-nitro-N-nitro-soguanidine (32.5 g.) and 200 ml. of 30% potassium hydroxide. The organic extract is washed with 5% sodium hydroxide, dried and concentrated to give methyl m-formylphenoxyacetate (17 g.), as a light yellow oil.
c. Methyl m-(Hydroxymethyl)phenoxyacetate. A solution of the product of step b (30.0 g.) in 200 ml. of methanol, cooled in an ice bath to 0°, is treated with sodium borohydride (1.55 g.) in 30 ml. of cold water. After the addition, stirring is continued for 20 min., the methanol is removed, and 60 ml. of brine is added. The aqueous phase is extracted with ether and the ether solution is washed, first with 5% aqueous hydrochloric acid, then brine, and dried. Removal of the solvent yields methyl m-(hydroxymethyl)phenoxyacetate(27.0 g.).
d. Methyl m-(Chloromethyl)phenoxyacetate. To the product of step c (27.0 g.) is added 20 ml. of thionyl chloride with stirring. Following the addition, the reaction mixture is stirred at 25° for 30 min. and at reflux for 30 min. After cooling the reaction mixture, it is dissolved in ether and washed carefully with water, saturated aqueous sodium bicarbonte and brine. The organic layer is dried, concentrated and distilled to give the title compound (11.0 g.) b.p. 98°-110°/0.03 mm.
Following the procedures of Preparation 2, but replacing chloroacetic acid with 3-chloropropionic acid, there is obtained, successively, 3-(m-formylphenoxy)propionic acid and its methyl ester, methyl 3-[m-(hydroxymethyl)phenoxy]-propionate, and the formula-LIII compound, methyl 3-[m-(chloromethyl)phenoxy]propionate.
Alternatively, Michael addition of m-hydroxy benzaldehyde to methyl acrylate, with base catalysis, and reduction of the product with sodium borohydride gives methyl 3-[m-(hydroxymethyl)phenoxy]propionate.
PREPARATION 3
Ethyl o-(Bromomethyl)benzyloxyacetate (Formula LIII: C g H 2g is a valence bond, C p H 2p and C q H 2q are methylene, C g H 2g and C p H 2p are in ortho relationship, Hal is bromo, R 26 is hydrogen, and R 10 is ethyl).
To a mixture of α,α'-dibromo-o-xylene (100 g.), ethyl glycolate (47 g.), and dimethylformamide (500 ml.) is added with stirring over a 1-hour period at 0°-5° C., 18 g. of 57% sodium hydride. The mixture is stirred for 16 hrs. at about 25° C. and is then concentrated on a rotating evaporator at 40°-50° C. under vacuum. The residue is diluted with one liter of a mixture of isomeric hexanes (Skellysolve B) and diethyl ether (1:2 by volume) and the organic solution is washed successively with dilute hydrochloric acid, dilute potassium hydroxide solution, water, and brine, and is finally dried and concentrated. The residue is chromatographed on a column prepared by wet-packing 3 kg. of silica gel (Brinkman) with 6 l. of 15% ethyl acetate in Skellysolve B and 30 ml. of absolute ethanol. Gradient elution of the column with 16 l. of 15-35% ethyl acetate in Skellysolve B gives fractions of 400 ml. each of which are combined on the basis of thin layer chromatography (TLC). From fractions 18-27 there is obtained 35 g. of the title compound. This material has λ max . in ethanol at 231 mμ (ε 7550) with shoulders at 272 (ε 700) and 278 mμ (ε 462). It has key absorptions in its NMR spectrum at about 7.3 (apparent singlet), 4.7 (singlet), 4.64 (singlet), 4.06 (singlet), 4.0-4.35 (quartet), and 1.1-1.34 (triplet) δ. It has mass spectral peaks at 206, 199, 201, 185, and 183.
PREPARATION 4
Endo-6-(cis-4-phenyl-1-butenyl)-bicyclo-[3.1.0]hexan-3-one (Formula XLIII: G is ##SPC104##
R 3 and R 4 are hydrogen; and ˜ is endo).
a. There is first prepared (3-phenylpropyl)triphenylphosphonium bromide. A solution of 597.3 g. of 1-bromo-3-phenylpropane and 786 g. of triphenylphosphine in 1,500 ml. of toluene is heated at reflux under nitrogen for 16 hrs., then the mixture is cooled and the solid product is separated by filtration. The solid is then slurried with toluene in a Waring blender, separated by filtration, and dried for 18 hrs. at 70° C. under reduced pressure to give 1068 g. of (3-phenylpropyl)triphenylphosphonium bromide; m.p. 210.5°-211.5° C.
b. A suspension of 314 g. of the product of step a in 3 l. of benzene is stirred at room temperature (25° C.) under nitrogen, and 400 ml. of 1.6 M butyllithium in hexane is added over a 20 min. period. The mixture is heated at 35° C. for 30 minutes, then is cooled to -15° C. and a solution of 100 g. of endo-bicyclo[3.1.0]hexan-3-ol-6-carboxaldehyde 3-tetrahydropyranyl ether in 200 ml. of benzene is added over a 30-min. period. This mixture is heated at 70° C. for 2.5 hrs., cooled, and filtered. The filtrate is washed three times with water, dried over sodium sulfate, and concentrated to 170 g. of crude endo-6-(cis-4-phenyl-1-butenyl)-bicyclo[3.1.0]hexan-3-ol 3-tetrahydropyranyl ether.
A solution of 340 g. (two runs) of this crude endo-6-(cis-4-phenyl-1-butenyl)-bicyclo-[3.1.0]hexan-3-ol 3-tetrahydropyranyl ether and 20 g. of oxalic acid in 3600 ml. of methanol is heated at reflux for 3.5 hrs. The mixture is cooled and the methanol is evaporated under reduced pressure. The residue is mixed with dichloromethane, and the dichloromethane solution is washed with aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated to 272 g. of the endo-6-(cis-4-phenyl-1-butenyl)bicyclo[3.1.0]-hexan-3-ol.
A solution of 93 g. of the above endo-6-(cis-4-phenyl-1-butenyl)bicyclo[3.1.0]hexan-3-ol in 2570 ml. of acetone is cooled to -5° C. and 160 ml. of Jones reagent (in the proportions 42 g. of chromic anhydride, 120 ml. of water, and 34 ml. of concentrated sulfuric acid) is added over a period of 30 min. while cooling to maintain a temperature of -5° C. The mixture is allowed to stand for 10 min. longer; then 100 ml. of isopropyl alcohol is added and the mixture is swirled for 5 min. The mixture is then diluted with 6 l. of water and extracted several times with dichloromethane. The organic layers are separated, washed with dilute hydrochloric acid, water, dilute aqueous sodium bicarbonate, and brine, then are dried over sodium sulfate, combined and concentrated to 83 g. of crude endo-6-(cis-4-phenyl-1-butenyl)-bicyclo[3.1.0]hexan-3-one.
Crude endo-6-(cis-4-phenyl-1-butenyl)-bicyclo[3.1.0]-hexan-3-one (162 g., two runs) is dissolved in isomeric hexanes (Skellysolve B) and chromatographed over 5 kg. of silica gel wet-packed with Skellysolve B, eluting successively with 11 l. of Skellysolve B, 62 l. of 2.5% ethyl acetate in Skellysolve B, and 32 l. of 5% ethyl acetate in Skellysolve B. The last 8 l. of the 2.5% ethyl acetate in Skellysolve B eluates and the 32 l. of 5% ethyl acetate in Skellysolve B eluates are combined and concentrated to 75.8 g. of the title compound; infrared absorption at 3000, 1750, 1610, 1500, 1455, 1405, 1265, 1150, 778, 750 and 702 cm - 1 ., N.M.R. peaks at 7.18 (singlet) and 4.75-6.0 (broad multiplet) δ.
PREPARATION 5
Endo-6-(cis-5-phenyl-1-pentenyl)-bicyclo-[3.1.0]hexan-3-one. (Formula XLIII: G is ##SPC105##
R 2 and R 9 are hydrogen; and ˜ is endo).
a. There is first prepared (4-phenylbutyl)triphenylphosphonium bromide. A solution of 145 g. of 4-phenyl-1-bromobutane and 179 g. of triphenylphosphine in 350 ml. of toluene is heated at reflux under nitrogen for 16 hrs. The mixture is then cooled slowly and ether is added giving a precipitate of (4-phenylbutyl)triphenylphosphonium bromide which is washed throughly with benzene/ether and dried 18 hrs. at 50° C. under reduced pressure, 268 g., m.p. 139°-140° C.
b. A suspension of 242 g. of the product of step a in 2.3 l. of dry benzene at 25° C. is stirred and 300 ml. of 1.6 M butyllithium in hexane is added over a 15-min. period. The mixture is stirred at 30° C. for one hour, then is cooled to 10° C. and a solution of 75 g. of endobicyclo-[3.1.0]hexan-3-ol-6-carboxaldehyde 3-tetrahydropyranyl ether in 200 ml. of benzene is added over a 15-min. period. The mixture is heated at 65°-70° C. for 3 hours, cooled and filtered. The filtrate is washed with water and brine, dried over sodium sulfate, and concentrated under reduced pressure to give 117 g. of crude endo-6-(cis-5-phenyl-1-pentenyl)-bicyclo[3.1.0]hexan-3-ol tetrahydropyranyl ether showing a single spot, R f 0.75, on thin layer chromatography with silica gel plates developed with 20% ethyl acetate in cyclohexane.
A solution of 117 g. of the above crude endo-6-(cis-5-phenyl-1-pentenyl)-bicyclo[3.1.0]hexan-3-ol tetrahydropyranyl ether and 6 g. of oxalic acid in 2,500 ml. of methanol is heated under reflux for 2.5 hrs. The methanol is then removed by distillation under reduced pressure and the residue is diluted with water and extracted with dichloromethane. The dichloromethane extracts are combined, washed with aqueous sodium bicarbonate and brine, dried over sodium sulfate and concentrated under reduced pressure to give 95.7 g. of crude endo-6-(cis-5-phenyl-1-pentenyl)-bicyclo[3.1.0]hexan-3-ol. The entire crude product is chromatographed over 1.5 kg. of silica gel wet-packed with Skellysolve B, eluting successively with 5 l. of Skellysolve B, 4 l. of 2.5%, 6 l. of 5%, 9 l. of 7.5%, 12 l. of 10%, 8 l. of 15%, 10 l. of 20% and 10 l. of 30% ethyl acetate in Skellysolve B, taking 600 ml. fractions. The last fraction of 10% ethyl acetate in Skellysolve B, all the 15% and 20% ethyl acetate in Skellysolve B eluates, and the first 3 fractions of 30% ethyl acetate in Skellysolve B are concentrated to 60.5 g. of purified endo-6-(cis-5-phenyl-1-pentenyl)bicyclo[3.1.0]hexan-3-ol.
A solution of 60.5 g. of the above purified alcohol in 1,600 ml. of acetone is cooled to -10° C. and 103 ml. of Jones reagent is added dropwise. After addition is complete the mixture is stirred for 10 min. at 0° C. and 65 ml. of isopropyl alcohol is added. The mixture is poured into 8 l. of water and extracted several times with dichloromethane. The dichloromethane extracts are combined, washed with dilute hydrochloric acid, aqueous sodium bicarbonate and brine, dried over sodium sulfate and concentrated under reduced pressure to give 56 g. of crude endo-6-(cis-5-phenyl-1-pentenyl)bicyclo[3.1.0]hexan-3-one. The crude ketone is slurried in Skellysolve B and chromatographed over 2,300 g. of silica gel wet packed in Skellysolve B, eluting successively with 6 l. of Skellysolve B, 16 l. of 2.5% ethyl acetate in Skellysolve B, then gradient elution with 5 l. of 2.5% and 5 l. of 5% ethyl acetate in Skellysolve B and finally 16 l. of 5% ethyl acetate in Skellysolve B, taking 625 ml. fractions. The last fraction of the gradient eluates and the first 19 fractions of 5% ethyl acetate in Skellysolve B are concentrated to give 23.6 of the title compound; infrared absorption at 2980, 1745, 1600, 1490, 1450, 1260, 1145, 770, 750 and 702 cm - 1 ., N.M.R. peaks at 7.17 (singlet), 6.0-5.4 (multiplet), and 5.2-4.7 (broad multiplet) δ.
PREPARATION 6
Endo-6-(1,2-dihydroxy-4-phenylbutyl)-bicyclo[3.1.0]hexan-3-one Acetonide (Formula XXXVI wherein G is ##SPC106##
R 2 and R 9 are hydrogen, R 11 and R 12 are methyl, and ˜ is endo).
a. There is first prepared the formula-LI dihydroxy compound. To a solution of endo-6-(cis-4-phenyl-1-butenyl)-bicyclo[3.1.0]hexan-3-one (10.0 g., Preparation 4) in about 100 ml. tetrahydrofuran is added, with stirring, a solution of potassium chlorate (10.0 g.) and osmium tetroxide (0.65 g.) in 250 ml. of water. The mixture is stirred vigorously for 5 hrs. at 50° C. Then, the cooled mixture is concentrated under reduced pressure. The residue is extracted repeatedly with dichloromethane, and the combined extracts are dried and concentrated to an oil. This oil is chromatographed on about 1000 g. of silica gel, and eluted successively with 3 l. of 10% ethyl acetate in a mixture of isomeric hexanes (Skellysolve B), with 5 l. of 25% ethyl acetate in Skellysolve B, and then with 50% ethyl acetate in Skellysolve B, collecting 500 ml. eluate fractions. Fractions 13-19 (50% ethyl acetate) are combined and evaporated to dryness to give dl-endo-6 (1,2-dihydroxy-4-phenylbutyl)-bicyclo[3.1.0]hexane-3-one (Formula LI).
b. A solution of the product of step a (about 8.0 g.) and 700 mg. of potassium bisulfate in 140 ml. of acetone is stirred at 25° C. for 64 hrs. Then sodium carbonate monohydrate (710 mg.) is added, and the mixture is stirred 10 minutes. The acetone is evaporated at reduced pressure, and water is added. The aqueous solution is extracted repeatedly with dichloromethane, and the extracts are combined, washed with water, dried, and concentrated to about 9.3 g. of an oil. The oil is chromatographed on 400 g. of silica gel, being eluted with 2 l. of 10% ethyl acetate in Skellysolve B, and then with 4 l. of 15% ethyl acetate in Skellysolve B. The 15% ethyl acetate eluates are concentrated to about 7.4 g. of the formula-XXXVI compound, endo-6-(1,2-dihydroxy-4-phenylbutyl)-bicyclo[3.1.0]hexan-3-one acetonide.
PREPARATION 7
Methyl 9-Bromo-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate. (Formula LIV: C j H 2j and C p H 2p are valence bonds in meta relationship, C q H 2q is methylene, Hal is bromo, R 26 is hydrogen and R 10 is methyl).
a. To a cold, stirred solution of m-vinylanisole (13.4 g.) in 40 ml. of diethyl ether is slowly added a solution of bromine (15.9 g.) in 60 ml. of diethyl ether. The ether solution is used directly in converting the product, m-(1,2-dibromoethyl)anisole to m-methoxyphenylacetylene by dehydrohalogenation (see T. H. Vaughn, J. Am. Chem. Soc. 56, 2064, 1934). The ether solution above is slowly added, with vigorous stirring, to a mixture of sodium amide prepared from sodium (4.6 g.) in about 200 ml. of liquid ammonia. When the reaction is complete, the volume is reduced about one-half, and an equal volume of water is cautiously added. A layer containing the product is separated, washed with dilute hydrochloric acid, dried, and distilled.
b. To a solution of the product of step a above in 250 ml. of dichloromethane, maintained at 0° C. under nitrogen, is added dropwise over about a 1-hour period with vigorous stirring a solution of about 15 ml. of boron tribromide in 200 ml. of dichloromethane. Cooling and stirring continue for one hour. When the reaction is complete as shown by TLC, there is added cautiously a solution of sodium carbonate in water to neutralize the mixture. Thereafter, the solution is saturated with sodium chloride (added as a solid), and the organic phase is separated and combined with additional ethyl acetate washings of the aqueous phase. The organic solutions are washed with brine, dried over sodium sulfate, and concentrated under reduced pressure to yield the acetylenic phenol.
c. To the product of step b (11.8 g.), is added gradually a solution of sodium ethoxide (prepared from sodium and absolute ethanol). Thereafter, ethylene chlorohydrin (8.0 g.) is added in small portions. When all has been added, the mixture is heated at reflux for about one hour or until completion, then filtered hot. The combined filtrate and ethanol washings are concentrated to remove alcohol, and the product distilled under reduced pressure.
To the hydroxyethyl ether (16.2 g.) as obtained above, cooled to 15°-20° C., is added 20 ml. of dihydropyran and 100 ml. of diethylether, and, with stirring, 1 ml. of anhydrous diethyl ether saturated with hydrogen chloride. After the exothermic reaction has diminished, the mixture is kept at 25° C. for 15 hours. The mixture is washed with aqueous sodium bicarbonate, water, and dried, then concentrated under reduced pressure to yield the tetrahydropyranyl ether.
d and e. To a solution of the product of step c (10 g.) in anhydrous tetranydrofuran (180 ml.) at -78° C. under argon is added the equivalent molecular amount of n-butyllithium in hexane. The resulting solution is stirred at -78° C. for an additional 30 minutes. A suspension of dry paraformaldehyde (two equivalents) in anhydrous tetrahydrofuran is added and the mixture warmed to room temperature over a 30-min. period. It is stirred an additional 1 hour and poured into brine, then extracted with ether, dried, and concentrated to yield the hydroxy compound.
f. The hydroxy compound of step e is converted to the bromo compound by first forming the mesyl derivative by reaction with methanesulfonyl chloride (4 ml.) in pyridine (80 ml.) at -20° C. The mixture is stirred 1 hour at -20° C., and then is poured into a stirred mixture of 3 normal hydrochloric acid (300 ml.) and ice water (500 ml.). This mixture is extracted with diethyl ether, the extract is washed with cold one normal hydrochloric acid and brine, then dried and concentrated. To a solution of the residue (mesyl derivative) in dry acetone (100 ml.) is added lithium bromide (5 g.) and the mixture stirred and heated at reflux one hour, then kept at 25° C. for 15 hours. The acetone is evaporated under reduced pressure, and the residue is extracted with diethyl ether. The extract is washed with water and brine, then dried and concentrated. The residue is chromatographed on silica gel, eluting with 10% ethyl acetate in Skellysolve B. Fractions shown by TLC to contain the product are combined and concentrated to give the formula-LX intermediate.
g. The product of step f above is converted to the corresponding carboxylic acid and its methyl ester as follows. The tetrahydropyranyloxy group is replaced by hydroxyl by contacting the product of f with a mixture of acetic acid/water/tetrahydrofuran (20/10/3) at 40° C. for 2 hours, thereafter removing solvents under reduced pressure.
The substituted glycol from above is oxidized to the acid in acetone solution, using a slight excess of Jones reagent (21 g. chromic anhydride/60 ml. water/17 ml. conc. sulfuric acid) while cooling to maintain a temperature of -5° to 0° C. After about 60 min., isopropyl alcohol is added, the mixture is stirred for 10 min., and then poured into ice water. The acid product is isolated by extraction with chloroform, drying over sodium sulfate, and concentration under reduced pressure.
The acid from above is converted to the methyl ester by reaction with diazomethane in diethyl ether at about 10°-25° C., followed by concentration to yield the desired title compound.
Following the procedures of Preparation 7, but replacing m-vinylanisole with methyl (o, m, or p-)vinylbenzyl ether, there are obtained, respectively, methyl 9-bromo-3-oxa-4,7-inter-o-phenylene-5,6-dinor-7-nonynoate, methyl 10-bromo-3-oxa-4,8-inter-m-phenylene-5,6,7-trinor-8-decynoate, and methyl 11-bromo-3-oxa-4,9-inter-p-phenylene-5,6,7,8-tetranor-9-undecynoate.
PREPARATION 8
Methyl 9-Bromo-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-cis-7-nonenoate (Formula LV: C j H 2j and C p H 2p are valence bonds in meta relationships. C q H 2q is methylene, Hal is bromo, R 26 is hydrogen and R 10 is methyl).
A solution of methyl 9-bromo-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate (2.0 g., Preparation 7) in 10 ml. of pyridine is hydrogenated in the presence of a 5% palladium on barium sulfate catalyst (150 mg.) at 25° C. and one atmosphere. The resulting mixture is filtered and evaporated to about one-third the original volume. Four volumes of ethyl acetate is added, and the remaining pyridine is removed by addition of ice and one N hydrochloric acid. The ethyl acetate layer is separated, washed successively with one N hydrochloric acid and brine, dried, and evaporated. The residue is chromatographed on 250 g. of silica gel which has previously been acid-washed to pH 4 (Silicar CC 4 , 100-200 mesh, Mallincrodt Co.), eluting with 3 l. of 25-75% ethyl acetate-Skellysolve B gradient, collecting 100 -ml. fractions. The fractions shown to have the desired product free of starting material by TLC are combined and concentrated under reduced pressure to give the title compound containing the cis --CH=CH moiety.
Following the procedures of Preparation 8, but replacing methyl 9-bromo-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate with methyl 9-bromo-3-oxa-4,7-inter-o-phenylene-5,6-dinor-7-nonynoate, methyl 10-bromo-3-oxa-4,8-inter-m-phenylene-5,6,7-trinor-8-decynoate, or methyl 11-bromo-3-oxa-4,9-inter-p-phenylene-5,6,7,8-tetra-nor-9-undecyanoate (from the paragraphs following Preparation 7), there is obtained the corresponding formula-LV enoate compounds in which cis--CH=CH-- has replaced --C.tbd.C--.
PREPARATION 9
Methyl 9-Bromo-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-trans-7-nonenoate. (Formula LVI: C j H 2j and C p H 2p are valence bonds in meta relationship, C q H 2q is methylene, Hal is bromo, R 26 is hydrogen and R 10 is methyl).
A solution of the compound represented by the formula ##SPC107##
(1.0 g., Preparation 7, step e) in 20 ml. of tetrahydrofuran is cooled to -10° C. This solution is added to a fresh solution of lithium aluminum hydride (110% of theory) in tetrahydrofuran. The reaction mixture is stirred for 16 hours at 25° C. ambient temperature. Then, water (20 ml.) is added, and the resulting solution is acidified with one N hydrochloric acid, and then extracted with ethyl acetate. The extract is washed successively with aqueous sodium bicarbonate solution and brine, dried, and evaporated under reduced pressure. The residue is chromatographed on silica gel, eluting with a 25-75% ethyl acetate-Skellysolve B gradient, combining fractions shown to have the desired product by TLC, and removing solvent from those combined fractions under reduced pressure to yield a compound represented by the formula ##SPC108##
Thereafter, following the procedures of Preparation 7, steps f through g, there is obtained the title compound containing the trans--CH=CH-- moiety.
Following the procedures of Preparation 9, but replacing that nonynoate with the compound having the formula ##SPC109##
wherein the THP-terminated moiety is attached to the ring in ortho, meta, or para configuration, there is obtained the corresponding formula-LVI compound in which trans --CH=CH-- has replaced --C.tbd.C--.
PREPARATION 10
Optically Active Bicyclo[3.1.0]-hex-2-ene-6-endo-carboxaldehyde
Following the procedure of Preparation 1 of U.S. Pat. No. 3,711,515, racemic bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde is prepared from bicyclo[2.2.1]hepta-2,5-diene and peracetic acid.
The racemic compound is resolved by the procedure of Example 13 of U.S. Pat. No. 3,711,515, forming an oxazolidine as follows.
Racemic bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde (12.3 g.) and 1-ephedrine (16.5 g.) are dissolved in about 150 ml. of benzene. The benzene is removed under vacuum and the residue taken up in about 150 ml. of isopropyl ether. The solution is filtered, then cooled to -13° C. to yield crystals of 2-endo-bicyclo-[3.1.0]hex-2-en-6-yl-3,4-dimethyl-5-phenyl-oxazolidine, 11.1 g., m.p. 90°-92° C. Three recrystallizations from isopropyl ether, cooling each time to about -2° C., yield crystals of the oxazolidine, 2.2 g., m.p. 100°-103° C., now substantially a single isomeric form as shown by NMR.
The above re-crystallized oxazolidine (1.0 g.) is dissolved in a few ml. of dichloromethane, charged to a 20 g. silica gel column and eluted with dichloromethane. The silica gel is chromatography-grade (Merck), 0.05-0.2 mm. particle size, with about 4-5 g. of water per 100 g. Fractions of the eluate are collected, and those shown by thin layer chromatography (TLC) to contain the desired compound are combined and evaporated to an oil (360 mg.). This oil is shown by NMR to be the desired title compound, substantially free of the ephedrine, in substantially a single optically-active isomeric form. Points on the circular dichroism curve are (λ in nm.,θ): 350, 0; 322.5, -4,854; 312, -5,683; 302.5, -4,854; 269, 0; 250, 2,368; 240, 0; and 210, -34,600.
EXAMPLE 1
dl-Methyl 7-[Endo-6-(1-heptenyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-heptanoate (Formula XLIV, Chart E: G is n-pentyl; R 2 , R 9 , and R 26 are hydrogen; R 10 is methyl; Z' is ##SPC110##
and ˜ is alpha and endo).
A. A solution prepared from endo-6-(1-heptenyl)-3-(1-pyrrolidyl)-bicyclo[3.1.0]hex-2-ene (Preparation 1, 5.0 g.) and methyl m-(chloromethyl)-phenoxyacetate (Preparation 2, 4.4 g.) in 60 ml. of dioxane is stirred under a nitrogen atmosphere at about 25° C for 2 days and then heated under reflux for 7 hrs. To the reaction mixture is added water. The solution is heated on a steam bath, cooled and extracted with ether. The extract is washed, first with dilute (about 5% hydrochloric acid, then brine, and dried and concentrated. The residue is chromatographed on 700 g. of silica gel prepared with 20% ether-isomeric hexane mixture (Skellysolve B) and eluted with 1.5 l. of 20% ether-Skellysolve B, 1.5 l. of 25% ether-Skellysolve B, and 1.5 l. of 30% ether-Skellysolve B, collecting 100-ml. fractions. Fractions 25-31 give the title compound (1.7 g.).
B. Alternate synthesis. - A solution of potassium tert-butoxide (9.0 g.) in 500 ml. of nitrogen-purged tetrahydrofuran is added dropwise during 45 min. to a stirred solution of the formula-XLIII bicyclo olefin, endo-6-(1-heptenyl)bicyclo[3.1.0]hexan-3-one (see Example 9 of West Germany Offenlegungsschrift No. 1,937,912, cited above) (10.0 g.), and methyl m-(chloromethyl)phenoxyacetate (Preparation 2, 13 g.) in 250 ml. of tetrahydrofuran under nitrogen at 25° C. The resulting mixture is acidified at once with 120 ml. of 5% hydrochloric acid, and then is concentrated under reduced pressure below 40° C. to remove most of the tetrahydrofuran. Water (400 ml.) is added to the residue, and the mixture is extracted with three 400-ml. portions of ethyl acetate. The combined extracts are washed successively with aqueous sodium thiosulfate solution and brine, dried, and concentrated under reduced pressure. The residue is chromatographed over 4 kg. of silica gel wet-packed with 20% ether-isomeric hexane mixture (Skellysolve B) and eluted with ether-Skellysolve B mixtures having 20-30% ether. Fractions shown by TLC to contain the desired alkylation product are combined to yield the formula-XLIV (Chart E) alkylated olefin title compound.
Following the procedure of Example 1-B but replacing the formula-XLIII (Chart E) endo-6-(1-heptenyl)bicyclo[3.1.0]hexan-3-one with the corresponding bicyclo olefins prepared by reaction of the -tetrahydropyranyl ether of endo-bicyclo[3.1.0]hexan-3-ol-6-carboxaldehyde with intermediate quaternary phosphonium halides (see above-cited West Germany Offenlegungsschrift No. 1,937,912) prepared from 1-bromobutane, 1-chloropentane, 1-bromoheptane, and 1-chlorooctane, there are obtained the corresponding formula-XLIV alkylated olefin compounds wherein G is straight chain alkyl of 3, 4, 6, and 7 carbon atoms, respectively.
Also following the procedure of Example 1-B but employing instead formula-XLIII bicyclo olefins prepared from 1-bromo-2-fluorobutane, 1-chloro-2-fluoro-pentane, 1-bromo-2-fluorohexane, 1-bromo-2-fluoroheptane, and 1-chloro-2-fluorooctane, there are obtained the corresponding formula-XLIV alkylated olefin compounds wherein G is straight chain alkyl of 3 to 7 carbon atoms, inclusive, with a fluoro substituent at the 1-position.
Also following the procedure of Example 1-B but employing, instead, formula-XLIII bicyclo olefins prepared from primary bromides of the formula R 27 --(CH 2 ) b --CH 2 Br, wherein b is one, 2, 3, or 4, and R 27 is isobutyl, tert-butyl, 3,3-difluorobutyl, 4,4-difluorobutyl, 4,4,4-trifluorobutyl, and 3,3,4,4,4-pentafluorobutyl, there are obtained compounds corresponding to the formula-XLIV product of Example 1-B with R 27 --(CH 2 ) b --CH=CH-- in place of the 1-heptenyl moiety.
Also following the procedure of Example 1-B but employing, instead, formula-XLIII bicyclo olefins prepared from primary bromides of the formula CH 3 --(CH 2 ) c --CR 21 R 22 --CH 2 Br wherein c is 2, 3, or 4, and R 21 and R 22 are methyl or ethyl, e.g. CH 3 --(CH 2 ) 2 --C(C 2 H 5 ) 2 --CH 2 --Br, CH 3 --(CH 2 ) 3 --CH(CH 3 )--CH 2 --Br, CH 3 --(CH 2 ) 3 --CH(C 2 H 5 )--CH 2 Cl, CH 3 --(CH 2 ) 3 --C(CH 3 ) 2 --CH 2 --Br, and CH 3 --(CH 2 ) 3 --C(CH 3 )(C 2 H 5 )--CH 2 Br, there are obtained the corresponding formula-XLIV alkylated olefin compounds wherein G is mono- or di-substituted at the 1-position with methyl or ethyl.
Also following the procedure with Example 1-B but employing, instead, formula-XLIII bicyclo olefins prepared from α-bromotoluene, (2-bromoethyl)benzene, (5-chloropentyl)-benzene, (6-bromohexyl)benzene, and (7-iodoheptyl)benzene; from (1-chloroethyl)-benzene, (1-bromopropyl)benzene, (2-bromopropyl)benzene, (3-chloropentyl)benzene, (4-bromopentyl)benzene, (6-bromononyl)benzene and (7-bromononyl)benzene; from 1-bromo-2-phenylpropane, 1-bromo-2-methyl-2-phenylpropane, 1-chloro-2-ethyl-3-phenylpropane, 1-bromo-2-methyl-4-phenylbutane, and 1-bromo-2,2-dimethyl-5-phenylpentane; from α-bromo-m-xylene, α-chloro-p-ethyltoluene, α-bromo-p-chlorotoluene, α'-chloro-α,α,α-trifluoro-m-xylene, 1-(2-bromoethyl)-4-fluorobenzene, 1-(5-bromopentyl)-2-chlorobenzene, 4-(3-iodopropyl)-1,2-dimethoxybenzene, and 1-(3-bromohexyl)-2,4,6-trimethylbenzene; and from (2-bromo-1-fluoroethyl)benzene, (2-bromo-1-fluoropropyl)benzene, (2-chloro-fluoro-1-methylpropyl)benzene, (5-bromo-4-fluoropentyl)benzene, (7-iodo-6-fluoropentyl)benzene, (4-bromo-3,3-difluorobutyl)benzene, and (6-bromo-5,5-difluorohexyl)benzene, there are obtained the corresponding formula-XLIV alkylated olefin compounds wherein G is ##SPC111##
including compounds wherein C t H 2t is substituted with one or 2 fluoro atoms.
Also following the procedure of Example 1-B, but using formula-XLIII bicyclo olefins obtained from the secondary bromides of the formula ##EQU50## wherein G and R 2 are as defined above, R 2 being alkyl, there are obtained formula-XLIV alkylated olefins corresponding to the product of Example 1-B with ##EQU51## in place of the 1-heptenyl moiety.
Also following the procedure of Example 1-B, but using formula-XLIII bicyclo olefins obtained from bicyclo[3.1.0]-hexane reactants with ##EQU52## in place of ##EQU53## wherein R 9 is as defined above, there is obtained formula-XLIII alkylated olefins corresponding to the product of Example 1-B with ##EQU54## in place of the 1-heptenyl moiety.
Also following the procedure of Example 1-B, but using formula-XLIII bicyclo olefins obtained from bicyclo-[3.1.0]hexane reactants with ##EQU55## in place of ##EQU56## and primary and secondary bromides of the formula ##EQU57## (as above defined), there are obtained formula-LIV alkylated olefins corresponding to the product of Example 1-B with ##EQU58## in place of the 1-heptenyl moiety.
Also following the procedure of Example 1-B but using a larger amount of potassium tert-butoxide (16 g.) and maintaining the reaction mixture for 8 hrs. at 25° C. before addition of hydrochloric acid, a product is obtained which contains substantial amounts of both the above described 2α-yl isomer and the corresponding 2β-yl isomer. These isomers are separated by the above-described silica gel chromatography.
Also following the procedure of Example 1-B but using exo formula-XLIII bicyclo olefins in place of the endo reactant of Example 1-B, there are obtained the corresponding exo formula-XLIV alkylated olefins.
Also following the procedure of Example 1-B but replacing the methyl m-(chloromethyl)phenoxyacetate alkylating agent with the formula-LIII and -LIV compounds, methyl 3-[m-chloromethyl)phenoxy]propionate, methyl 9-bromo-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate, and methyl 10-bromo-3 -oxa-4,8-inter-m-phenylene-5,6,7-trinor-8-decynoate, there are obtained alpha and beta, exo and endo, formula-XLIV alkylated olefins corresponding to the product of Example 1-B with ##SPC112##
replaced with ##SPC113## ##SPC114##
respectively. In the same manner, but using, according to Example 1-B, other esters of the above-described formula-LIII and -LIV alkylating agents within the scope of R 10 as above-defined, e.g., the isopropyl, tert-butyl, octyl, cyclohexyl, benzyl, and phenyl esters, there are obtained the corresponding formula-XLIV esters.
Also following the procedure of Example 1-B, but using in combination each of the above-described alternative formula-XLIII bicyclo olefins and each of the above-described alternative formula-LIII or -LIV omega-halo alkylation agents, there are obtained formula-XLIV alkylated olefins corresponding to the product of Example 1-B but different therefrom with respect to both the carboxylate-terminated side chain and the side chain attached to the cyclopropane ring in the product.
Also following the procedure of example 1-B, but using in place of the formula-LIII halo alkylating agent of that Example, each of the other alkylating agents within the scope of ##EQU59## as above defined, i.e., alkylating agents of formulas LIII and LIV as above-described, there are obtained alpha and beta exo and endo formula-XLIV compounds corresponding to the product of Example 1-B with each of the other ##EQU60## side chains in place of the ##SPC115##
side chain of the Example 1-B product. For example, using as formula-LIII alkylating agents in the Example 1-B procedure, the following compounds wherein Et is ethyl; ##SPC116##
there are obtained exo and endo, alpha and beta, formula-XLIV alkylated bicyclo[3.1.0]hexanes each having a carboxylate-terminated side chain corresponding to one of the specific omega-halo alkylating agents. For example, the side chain will be alpha or beta ##SPC117##
when the alkylating agent is ##SPC118##
Also following the procedure of Example 1-B, but using in combination each of the alternative alkylating formula-LIII and -LIV agents within the scope of ##EQU61## including the specific examples of those just mentioned, and each of the above-described formula-XLIII alternative bicyclo[3.1.0]hexane olefin reactants, there are obtained formula-XLIV exo and endo, alpha and beta, compounds corresponding to the products of Example 1-B, but different therefrom with respect to both the carboxylate-terminated side chain and the side chain attached to the cyclopropane ring of the product. In the same manner, alternative alkylating agents within the scope of ##EQU62## wherein R 10 is other than ethyl, e.g., methyl, isopropyl, tert-butyl, octyl, cyclohexyl, benzyl, phenyl, and β,β,β-trichloroethyl are used.
EXAMPLE 2
dl-Methyl 7-[Endo-6-(1,2-dihydroxyheptyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-heptanoate (Formula XLV, Chart E: G' is n-pentyl; R 2 , R 9 , and R 26 are hydrogen; R 10 is methyl; Z' is ##SPC119##
and ˜ is alpha and endo).
Refer to Chart E. To a solution of dl-methyl 7-[endo-6-(1-heptenyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-heptanoate (Example 1, 1.7 g.) in 30 ml. of tetrahydrofuran at 50° is added with stirring osmium tetroxide (200 mg.) followed by potassium chlorate (1.2 g.) and 15 ml. of water. The reaction mixture is maintained at 50° for 2 hrs., cooled, the tetrahydrofuran is removed, and the aqueous phase is extracted with dichloromethane. The organic layer is dried and concentrated and the residue is chromatographed on 200 g. of silica gel. The column is eluted with 1 l. of 35% ethyl acetate-benzene and 1 l. of 40% ethyl acetate-benzene, collecting 30-ml. fractions. Fractions 26-30 contain one isomer (faster moving, less polar) of the title compound (350 ml.). Fractions 32-37 contain the other slower-moving (more polar) isomer (450 mg.). These materials show infrared spectral absorption at 330 cm - 1 .
Following the procedure of Example 2 but using the hex-2β-yl isomer in place of the hex-2α-yl isomer of the bicyclo reactant, dl-methyl 7-[endo-6-(1,2-dihydroxyheptyl)-3-oxobicyclo[3.1.0]hex-2β-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-heptanoate is obtained.
Also following the procedure of Example 2, each of the formula-XLIV exo and endo, alpha and beta, saturated and acetylenic bicyclo[3.1.0]hexane esters defined above after Example 1 is oxidized to mixtures of the corresponding isomeric formula-XLV dihydroxy compounds.
EXAMPLE 3
dl-3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 Methyl Ester (Formula XVI: C g H 2g and C p H 2p are valence bonds in metal relationship, G is n-pentyl,Q is ##EQU63##
R 1 is methyl, and ˜ is alpha) and dl-15-Beta-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 Methyl Ester ##EQU64##
Refer to Chart E. To a solution of the formula-XLV dihydroxy compound dl-methyl 7-[endo-6-(1,2-dihydroxyheptyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-heptanoate (800 mg. of a mixture of the slower and faster moving isomers of Example 2) in 10 ml. of pyridine, cooled to 0°, is added 1.2 ml. of methane-sulfonyl chloride. The reaction mixture is stirred for 2 hrs. and 20 g. of ice is added. The mixture is extracted with ether-dichloromethane (1:1) and the organic layer is washed successively with dilute hydrochloride acid, water, saturated aqueous sodium bicarabonate, and brine, dried, and concentrated. The residue, containing the bismesylate, is treated with 15 ml. of acetone and 10 ml. of water and stirred for 8-16 hrs. at 25°. The acetone is removed in vacuo and the remaining solution is extracted with dichloromethane. The extract is dried and concentrated and the residue is chromatographed on 150 g. of silica gel using 500 ml. ethyl acetate followed by 3% methanol ethyl acetate as eluting solvent while collecting 30-ml. fractions. Fractions 15-24 are combined and concentrated to yield the 15-β PGE 1 title compound (50 mg.); mass spectral peak at 404; ultraviolet absorption at 216 (ε = 8100), 264 (ε = 1100), 272 (ε = 1600) and 278 (ε = 1500) mμ. Fractions 26-35 are combined and concentrated to yield a residue which is re-chromatographed on 10 g. of silica gel using the same solvent system and collecting 1.5 ml. fractions. Fractions 22-29 are combined and concentrated to give the PGE 1 title compound (75 mg.); mass spectral peak at 404; ultraviolet absorption at 216 (ε = 7700), 264, 272 (ε = 1500), and 278 (ε = 1400) mμ.
Following the procedures of Example 3, each of the formula-XLV dl-endo-1,2-dihydroxy oxa-phenylene esters following Example 2 is transformed to the corresponding dl-endo-1,2-dimesyloxy oxa-phenylene ester, and thence to the corresponding PGE type compound or its isomers.
Also following the procedures of Example 3, each of the formula-XLV and dl-exo-1,2-dihydroxy-oxa-phenylene esters corresponding to the above dl-endo-1,2-dihydroxy esters is transformed to the corresponding dl-exo-1,2-dimesyloxy ester, and thence to the corresponding PGE type compound or its isomers.
By the above-outlined procedures, following the steps of Chart E, there are obtained the specific PGE-type esters represented by figures XVI and XVIII, e.g. the esters of the dl-oxa-phenylene PGE 1 compounds and 5,6-dehydro-PGE 2 compounds, including their 8-iso and 15-epi (β) forms. For example, dl-5,6-dehydro-3-oxa-3,7-inter-m-phenylene-18-phenyl-4,19,20-trinor-PGE.sub.2 methyl ester and its 15-epimer are obtained from dl-methyl 7-[endo-6-(cis-4-phenyl-1-butenyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate (Example 10 hereinafter) by way of the dihydroxy and bis(mesylate) intermediates of Chart E, following Example 3, as represented by the following formulas: ##SPC120##
Also following the procedure of Example 3, but replacing methanesulfonyl chloride with an alkanesulfonyl chloride or bromide or with an alkanesulfonic acid anhydride, wherein the alkane moiety contains 2 to 5 carbon atoms inclusive, there is obtained from each dihydroxy compound the corresponding bis(sulfonic acid) esters encompassed by formula XLVI.
In each of the above the in Example 3, the monosulfonic acid ester is also obtained as a byproduct, which is reacted with additional alkanesulfonyl halide or alkanesulfonic acid anhydride to give the corresponding bis(sulfonic acid) ester and thence recycled back to additional formula-XLVII product.
For satisfactory yields of the bis-sulfonic acid ester, R 10 is not hydrogen. Those intermediate compounds in which R 10 is haloethyl, e.g., β,β,β-trichloroethyl, are especially useful in the sequence of reactions leading to the acid form of the prostaglandin-like products. Each of the exo and endo, alpha and beta, saturated and unsaturated oxa-phenylene bis(alkanesulfonic acid) esters is transformed to the corresponding oxa-phenylene PGE type compound encompassed by formula-XLVII.
EXAMPLE 4
dl-3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α Methyl Ester and dl-3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.β Methyl Ester (Formula XX: C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU65##
R 1 is methyl, and ˜ is alpha for the carboxyl-containing moiety and either alpha or beta for the ring hydroxyl).
Refer to Chart A. A solution of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 methyl ester (Example 3, 300 mg.), 20 ml. of tetrahydrofuran, 2.0 ml. of hexamethyldisilazane, and 0.15 ml. of trimethylsilyl chloride is stirred at 25° for 20 hrs. The reaction mixture is concentrated in vacuo, benzene is added, the solution concentrated and this procedure is repeated. The residue is dissolved in 10 ml. of methanol, cooled in an ice-methanol bath, and sodium borohydride (60 mg.) in 20 ml. of cold water is added dropwise. The methanol is removed and the aqueous phase is extracted with dichloromethane, and the resulting dichloromethane solution is dried and concentrated in vacuo. The residue is chromatographed on 45 g. of silica gel using 70 ml. of ethyl acetate and then a gradient of 0-8% methanol ethyl acetate as eluting solvent, collecting 10-ml. fractions. Fractions 22-36 are combined and concentrated to yield the PGF 1 .sub.α -type title compound (100 mg.); mass spectral peak for tris-trimethylsilyl derivative at 622. Fractions 37-42 are combined and concentrated to yield a residue which is chromatographed on a preparative silica gel plate using 5% methanol-methylene chloride as eluting solvent. From the plate is obtained the PGF 1 .sub.β -type title compound (25 mg.); mass spectral peak for tris-trimethylsilyl derivative at 622.
Following the procedure of Example 4, dl-3-oxa-4,7-inter-o-phenylene-5,6-dinor-PGE 1 ethyl ester (Example 8 hereinafter) is transformed to dl-3-oxa-4,7-inter-o-phenylene-5,6-dinor-PGF 1 .sub.α and -PGF 1 .sub.β ethyl esters.
Also following the procedure of Example 4, dl-5,6-dehydro-3-oxa-3,7-inter-m-phenylene 18-phenyl-4,19-20-trinor-PGE 2 methyl ester (following Example 3) is transformed to the corresponding PGF 2 .sub.α and PGF 2 .sub.β type compounds.
Also following the procedure of Example 4, the alkyl ester and free acid forms of formula-XX to -XXIII oxa-phenylene PGF compounds in their various spatial configurations, e.g., the PGF 1 .sub.α, PGF 1 .sub.β, PGF 2 .sub.α, PGF 2 .sub.β, trans-5,6-dehydro-PGF 1 .sub.α and -PGF 1 .sub.β type compounds and their 8-iso and 15-beta isomers, are prepared by reduction of the corresponding formula XVI-to -XIX PGE-type alkyl ester or free acid, including those described above after Example 3.
EXAMPLE 5
dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 formula-XXIV: C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-C 5 H 11 ,Q is ##EQU66##
R 1 is hydrogen; and ˜ is alpha).
Refer to Chart A. A solution of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 methyl ester (Example 3, 300 mg.), 4 ml. of tetrahydrofuran and 4 ml. of 0.5 N hydrochloric acid is left standing at 25° for five days. Brine solution and dichloromethane-ether (1:3) are added and the mixture is stirred. The organic layer is separated, dried and concentrated. The residue is dissolved in ether which is washed with saturated aqueous sodium bicarbonate, dried and concentrated. The aqueous phase is quickly acidified with hydrochloric acid and extracted with dichloromethane which in turn is dried and concentrated. The residue is again dissolved in ether, extracted with aqueous sodium bicarbonate, and the aqueous phase is worked up as reported above. This procedure is repeated one additional time to yield the title compound (120 mg.). This material has mass spectral peaks at 372, 354, 189, and 185; and λ max., in ethanol, 215 mμ (ε 12,400), 272 (ε 2250) and 278 (ε 2150).
Following the procedure of Example 5, the formula XIV-to -XIX PGE compounds in their various spatial configurations described after Example 3 are transformed to the corresponding formula XXIV-to -XXVII PGA compounds, either as esters or as free acids.
EXAMPLE 6
dl-Ethyl 7-[Endo-6-(1-heptenyl)-3-oxobicyclo-[3.1.0]hex-2α-yl]-3-oxa-4,7-inter-o-phenylene-5,6-dinor-heptanoate (Formula-XLIV: G is n-pentyl; R 2 , R 9 , and R 26 are hydrogen; R 10 is ethyl; Z' is ##SPC121##
and ˜ is alpha and endo).
The enamine of the formula-XLIII bicyclo-olefin is first prepared as follows. A mixture of endo-6-(cis- and trans-1-heptenyl)-bicyclo[3.1.0]hexan-3-one (10 g.), benzene (200 ml.), and pyrrolidine (15 ml.) is heated at reflux under a Dean-Stark water trap for 2 hrs. Thereafter about 140 ml. of distillate is taken off over a period of about 30 min. To the remaining liquid is added 100 ml. of toluene and the mixture is concentrated on a rotating evaporator under vacuum. A second portion of toluene (50 ml.) is added, and the mixture concentrated to give the enamine residue.
The above enamine, together with ethyl o-(bromomethyl)-benzyloxyacetate (Preparation 3 above, 15 g.), and dry tetrahydrofuran (200 ml.) is heated at reflux for 4 hrs. and thereafter stirred at about 25° C. for 16 hrs. Water (25 ml.) is added and the mixture heated for 20 min. on a steam bath. Thereafter, the volatiles are removed under vacuum, the residue is diluted with ether, and the organic solution is washed successively with dilute acid, water, dilute base, water, and brine, and finally dried and concentrated under vacuum. The residue is chromatographed on a column prepared by wet-packing 1300 g. of silica gel (E. Merck) with 2.5 l. of 25% diethyl ether in Skellysolve B and 13 ml. of absolute ethanol. The column is eluted with 2 l. of 25% ether in Skellysolve B and then gradient-eluted with 8 l. of 25-50% ether-Skellysolve B. Fractions of about 200 ml. are combined on the basis of TLC data. From fractions 24-31 there is obtained 2.9 g. of the desired formula-XLIV title compound as a mixture of cis and trans forms. This material has key absorptions in its NMR spectrum at about 7.21 (apparent singlet), 5.38-5.8 (multiplet), 4.62 (singlet), 4.06 (singlet), and 4.0-4.35 (quartet) δ. It has mass spectral lines at 398 and 294.
EXAMPLE 7
dl-Ethyl 7-[endo-6-(1,2-dihydroxyheptyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-4,7-inter-o-phenylene-5,6-dinor heptanoate (Formula-XLV: G' is n-pentyl; R 2 , R 9 , and R 26 are hydrogen; R 10 is ethyl; Z' is ##SPC122##
and ˜ is alpha and endo).
Refer to one E. To a solution of dl-ethyl 7-[endo-6-(1-heptenyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-4,7-inter-o-phenylene-5,6-dinor-heptanoate, as a mixture of its isomers (Example 6, 2.8 g.) in dry tetrahydrofuran (150 ml.) at 50° C. is added 0.15 g. of osmium tetroxide followed by 2.8 g. of potassium chlorate in 60 ml. of water. The mixture is stirred vigorously at 50° C. for about 1.5 hrs. and is then concentrated under vacuum. The residue is extracted with dichloromethane. The extract is washed with water and brine, and then finally dried and concentrated under vacuum. The residue is chromatographed on a column prepared by wet-packing 500 g. of silica gel (E. Merck) with 1 liter of 50% ethyl acetate in Skellysolve B and 5 ml. of absolute ethanol. The column is eluted with 1 l. of 50% ethyl acetate in Skellysolve B and then gradient eluted with 4 l. of 50-75% ethyl acetate in Skellysolve B. Fractions of 100 ml. each are combined on the basis of TLC data. From fractions 12-29 there is obtained 2.6 g. of the title compound.
EXAMPLE 8
dl-3-Oxa-4,7-inter-o-phenylen-5,6-dinor-PGE 1 Ethyl Ester (Formula-XIV: C g H 2g is a valence bond, C p H 2p are in ortho relationship, G is n-pentyl, Q is ##EQU67##
R 1 is ethyl, and ˜ is alpha) and dl-15-Beta-3-oxa-4,7-inter-o-pnenylene-5,6-dinor-PGE 1 Ethyl Ester ##EQU68##
Refer to Chart E. The formula-XLVI bismesylate is first prepared as follows. To a mixture of dl-ethyl 7-[endo-6-(1,2-dihydroxyhepthyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-4,7-inter-o-phenylene-5,6-dinor-heptanoate (Example 7, 2.6 g.) and 30 ml. of dry pyridine at 0° C. is added, with stirring, 2.7 ml. of methanesulfonyl chloride over a one-minute period. The mixture is stirred at 0° C. for 2.5 hrs., then cooled to about -10° C. and diluted with 2 ml. of water added dropwise over a 5-minute period. Ice (20 g.) is added, and, after stirring the mixture for 5 min., about 150 ml. of ether-dichloromethane (3:1) is added. The organic solution was washed successively with dilute hydrochloric acid, water, dilute sodium bicarbonate solution, and brine, and finally dried and concentrated under vacuum to yield a mixture of the mesylates.
The residue of mesylates is converted to the PGE-type product by contacting with a mixture of acetone (100 ml.) and water (50 ml.) at about 25° C. for 16 hrs. Additional water (100 ml.) is added and the mixture concentrated under vacuum to remove acetone. The residue is extracted with a mixture of ether-dichloromethane (3:1) and the organic extract is washed with dilute sodium bicarbonate solution and brine, then dried and concentrated under vacuum. The residue (2.5 g.) is chromatographed on a column prepared by wet-packing 500 g. of silica gel (E. Merck) with one liter of ethyl acetate and 5 ml. of absolute ethanol. The column is eluted with 2.6 liters of ethyl acetate, then 400 ml. of 2% ethanol in ethyl acetate, then 500 ml. of 4% ethanol in ethyl acetate and finally with 2 liters of 10% ethanol in ethyl acetate, collecting fractions of 100 ml. Fractions are combined on the basis of TLC data.
From fractions 8-14 is obtained 350 mg. of the 15-β PGE 1 title compound. This material has λ max . 279 mμ (ε 19,400) in alcoholic potassium hydroxide; key absorptions in the NMR spectrum at about 7.2 (apparent singlet), 5.25-5.48 (multiplet), 4.58 (singlet), 5.25-5.48 (multiplet), 4.58 (singlet) 4.06 singlet, and 4.0-4.35 (quartet) δ; and mass spectral peaks at 414, 396, 310, and 292.
From fractions 18-37 is obtained 496 mg. of the PGE 1 title compound. This material has λ max . 279 mμ (ε 21,750) in alcoholic potassium hydroxide; key absorptions in the NMR spectrum at about 7.18 (apparent singlet), 5.25-5.41 (multiplet), 4.58 (singlet), 4.02 (singlet), and 3.99-4.34 (quartet) δ; and mass spectral peaks at 414, 396, 310, and 292.
EXAMPLE 9
dl-Methyl 9-[Endo-6-(1,2-dihydroxy-2-methylheptyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-cis-7-nonenoate Acetonide (Formula-XXXVII, Chart D: G is n-pentyl; J' is ##SPC123##
R 9 and R 26 are hydrogen; R 2 , R 10 , R 11 , and R 12 are methyl; and ˜ is endo and alpha).
Refer to the sequence of reactions from formula-L to formula XXVI, and to Chart D.
a. There is first prepared the formula-XLIII olefin. Following the procedure for the Wittig synthesis in Examples 27, 28, and 29 of West Germany Offlegungsschrift 1,937,912, cited above, but employing tetrahydropyranyloxy ether of endo-bicyclo[3.1.0]hexan-3-ol-6-carboxaldehyde and the Wittig ylide of 2-chloroheptane, there is obtained dl-endo-6-(2-methyl-1-heptenyl)-3-oxobicyclo[3.1.0]-hexan-3-one.
b. To a solution of the product of step a above (approximately 10.0 g.) in water is added a solution of potassium chlorate (10.0 g.) and osmium tetroxide (0.65 g.) in 250 ml. of water. The mixture is stirred vigorously for 5 hrs. at 50° C. Then, the cooled mixture is concentrated under reduced pressure, the residue is extracted repeatedly with dichloromethane, and the combined extracts are dried and evaporated. The residue is chromatographed on about 1000 g. of silica gel, and eluted successively with 3 l. of 10% ethyl acetate in a mixture of isomeric hexanes (Skellysolve B), with 5 l. of 25% ethyl acetate in Skellysolve B, and then with 50% ethyl acetate in Skellysolve B, collecting 500 ml. eluate fractions. Fractions shown by TLC to contain the desired product are combined and evaporated to dryness to give the formula-LI product, dl-endo-6-(1,2-dihydroxy-2-methylheptyl)bicyclo[3.1.0]hexan-3-one.
c. A solution of the product of step b above (about 8,0 g.) and 700 mg. of potassium bisulfate in 140 ml. of acetone is stirred at 25° C. for 64 hrs. Then, sodium carbonate monohydrate (710 mg.) is added, and the mixture is stirred 10 min. The acetone is evaporated at reduced pressure, and water is added. The aqueous solution is extracted respectedly with dichloromethane, and the extracts are combined, washed with water, dried, and evaporated. The residue is chromatographed on 400 g. of silica gel, being eluted with 2 l. of 10% ethyl acetate in Skellysolve B, and then with 4 l. of 15% ethyl acetate in Skellysolve B. The 15% ethyl acetate eluates are evaporated to give the formula-XXXVI ketal, dl-endo-6-(1,2-dihydroxy-2-methylheptyl)bicyclo[3.1.0]hexan-3-one acetonide.
d. To prepare the formula-XXXVII compound (Chart D), the ketal above is alkylated following the procedure of Example 1-B, but using the formula-XXXVI ketal above instead of the formula-XLIII bicyclo olefin, and, replacing methyl m-(chloromethyl)phenoxyacetate with methyl 9-chloro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-cis-7-nonenoate (Preparation 8, above), thereby yielding the desired formula-XXXVII title compound.
As shown in Chart D, the formula-XXXVII alkylated ketal is transformed via the formula-XXXVIII glycol, thence the mesylate, to a PGE-type compound. Concentrated hydrochloric acid (2.5 ml.) is added to a solution of the formula-XXXVII product above (about 2.0 g.) in a mixture of 50 ml. of tetrahydofuran and 2.5 ml. of water. The mixture is stirred at 25° C. under nitrogen for 6 hrs. The resulting mixture is then concentrated under reduced pressure, and the residue is extracted with ethyl acetate. The extract is washed with brine, dried, and concentrated to dl-methyl-9[endo-6-(1,2-dihydroxy-2-methylheptyl)-3-oxobicyclo[3.1.0.]hex-2α-yl]-3-oxa-3,7- inter-m-phenylene-4,5,6-trinor-cis-7-nonenoate (formula-XXXVIII). Thereafter, following the procedure of Example 3, there is obtained dl-15-methyl-3-oxa-3,5-inter-m-phenylene-4-nor-PGE 2 methyl ester.
Following the procedure of Example 9, but using formula-XLIII exo reactants in place of the endo reactant, there are obtained exo products in each corresponding intermediate of Example 9.
With excess base (e.g., 26 g.) and a longer reaction time (e.g., 24 hrs. at 25° C.) during the alkylation step, the production of a substantial amount of the beta isomer is assured.
Following the procedures of Examples 9-d, but using the trans-7-nonenoate of Preparation 9, above, instead of the cis-7-nonenoate, there is obtained the corresponding formula-XXXVII alkylated ketal wherein the carboxy side chain is in trans configuration instead of cis.
Also following the procedures of Example 9, but replacing the formula-XLIII olefin with each of the endo and exo forms of the formula-XLIII bicyclo olefins described in the paragraphs following Example 1, there are obtained the corresponding alpha and beta, exo and endo, alkylated ketals within the scope of formula XXXVII.
Also following the procedures of Example 9-d, but replacing methyl 9-chloro-3-oxa-3,7-inter-m-phenylene-4,5,6,-trinor-cis-7-nonenoate with the formula-LV compounds of the paragraphs following Preparations 8 and 9, viz. cis or trans methyl 9-bromo-3- oxa-4,7-inter-o-phenylene-5,6-dinor-7-nonenoate, methyl 10-bromo-3-oxa-4,8-inter-m-phenylene-5,6,7-trinor-8-decenoate, and methyl 11-bromo-3-oxa-4,9-inter-p-phenylene-5,6,7,8-tetranor-9-undecenoate, there are obtained the corresponding formula-XXXVII compounds. Thereafter, these alkylated ketals are transformed following the steps of Chart D as described in Example 9 to the corresponding PGE 2 type compounds.
Also following the procedure of Example 9-d, but using in place of the nonenoate alkylating agent, methyl m-(chloromethyl)phenoxyacetate(Preparation 2), ethyl o-(bromoethyl)benzyloxyacetate (Preparation 3), methyl 9-bromo-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate (Preparation 7), and methyl 11-bromo-3-oxa-4,9-inter-p-phenylene-5,6,7,8-tetranor-9-undecyanoate (following Preparation 7), there are obtained alpha and beta, exo and endo, compounds corresponding to the product of Example 9 with ##SPC124##
in place of the ##SPC125##
moiety of the Example-9 formula-XXXVII product. In the same manner, but using formula LIII-to -LVI alkylating agents within the scope of the formula ##EQU69## there are obtained the corresponding formula-XXXVII products.
Also following Example 9-d, other esters of the nonenoate alkylating agent and of the other above-mentioned alkylating agents within the scope of R 10 as above-defined, e.g., the methyl, isopropyl, tert-butyl, octyl, β,β,β-trichloroethyl, cyclohexyl, benzyl, and phenyl esters, there are obtained the corresponding esters of these alpha and beta, exo and endo, formula-XXXVII bicyclo[3.1.0]hexane cyclic ketak alkylation products.
Also following the procedure of Example 9 but using in combination each of the above-described alternative formula-XLIII bicyclo[3.1.0]hexane olefin reactants (e.g. following Example 1) and each of the above-described omega-halo alkylation reactants within the scope of ##EQU70## (e.g. following Example 1) there are obtained formula-XXXVII compounds corresponding to the product of Example 9 but different therefrom with respect to both the carboxylate-terminated side chain and the side chain attached to the cyclopropane ring of the product, and in their respective alpha or beta and exo or endo configuration.
Following the procedure of Example 9 but using in place of the acetonide each of the specific formula-XXXVII exo and endo, alpha and beta, saturated, cis and trans -phenyl-and acetylenic bicyclo[3.1.0]hexane cyclic ketal esters defined above, there are obtained the corresponding formula-XXXVIII dihydroxy compounds, and thence the corresponding PGE type compounds.
EXAMPLE 10
dl-Methyl 7-[Endo-6-(cis-4-phenyl-1-butenyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate (Formula-XLIV, Chart E; G is ##SPC126##
R 2 , r 9 , and R 26 are hydrogen; R 10 is methyl; Z' is ##SPC127##
and ˜ is endo and alpha).
Refer to Chart E. Following the procedures of Example 1-B, but replacing endo-6-(1-heptenyl)bicyclo[3.1.0]-hexan-3-one with endo-6-(cis-4-phenyl-1-butenyl)-bicyclo[3.1.0]hexan-3-one (Preparation 4), and replacing methyl m-(chloromethyl)phenoxyacetate with methyl 9-chloro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate (Preparation 7), there is obtained the title compound.
EXAMPLE 11
dl-Methyl 7-[Endo-6-(4 -phenyl-1,2-dimesyloxy-butyl)-3-oxobicyclo[3.1.0.]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate (Formula-XLVI, Chart E; G' is ##SPC128##
R 2 , r 9 , and R 26 are hydrogen; R 10 and R 13 are methyl; Z' is ##SPC129##
and ˜ is alpha and endo).
a. There is first prepared the formula-XLV dihydroxy compound. Following the procedures of Example 2, but replacing dl-methyl 7-[endo-6-(1-heptenyl)-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-heptanoate with dl-methyl 7-[endo-6-(cis-4-phenyl-1-butenyl)-3-oxobicyclo[3.1.0]hex-2α-yl-]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate (Example 10), there are obtained isomers of the desired formula-XLV compound, dl-methyl 7-[endo-6-(4-phenyl-1,2-dihydroxybutyl)-3 -oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7nonynoate.
b. Following the procedures of Example 3, but replacing that formula-XLV dihydroxy heptanoate compound with the formula-XLV nonynoate compound of A above, there is obtained the desired formula-LXVI dimesyloxy title compound.
EXAMPLE 12
dl-Methyl 9-[Endo-6-(1,2-dihydroxy-4-phenyl-butyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-trans-7-nonenoate Acetonide (Formula-XXVII, Chart D: G is ##SPC130##
J' is trans ##SPC131##
R 2 , R 9 , and R 26 are hydrogen; R 10 , R 11 , and R 12 are methyl; and ˜ is endo and alpha)
Refer to the sequence of reactions from formula L to formula XXXVI, and to Chart D.
a. There is first prepared the formula-Ll dihydroxy compound. To a solution of the formula-XLIII olefin (Preparation 4, above, approximately 10.0 g.) in water is added a solution of potassium chlorate (10.0 g.) and osmium tetroxide (0.65 g.) in 250 ml. of water. The mixture is stirred vigorously for 5 hrs. at 50° C. Then, the cooled mixture is concentrated under reduced pressure, the residue is extracted repeatedly with dichloromethane, and the combined extracts are dried and concentrated. The residue is chromatographed on about 1000 g. of silica gel, and eluted successively with 3 l of 10% ethyl acetate in a mixture of isomeric hexanes (Skellysolve B), with 5 l. of 25% ethyl acetate in Skellysolve B, and then with 50% ethyl acetate in Skellysolve B, collecting 500 ml. eluate fractions. Fractions shown by TLC to contain the desired product are combined and evaporated to dryness to give dl-endo-6-(1,2-dihydroxy-4-phenylbutyl)-bicyclo[3.1.0]hexan-3-one (formula-LI).
b. A solution of the product of step a above (about 8.0 g.) and 700 mg. of potassium bisulfate in 140 ml. of acetone is stirred at 25° C. for 64 hrs. Then, sodium carbonate monohydrate (710 mg.) is added, and the mixture is stirred 10 min. The acetone is concentrated at reduced pressure, and water is added. The aqueous solution is extracted repeatedly with dichloromethane, and the extracts are combined, washed with water, dried, and concentrated. The residue is chromatographed on 400 g. of silica gel, being eluted with 2 l. of 10% ethyl acetate in Skellysolve B, and then with 4 l. of 15% ethyl acetae in Skellysolve B. The 15% ethyl acetate eluates are concentrated to the formula-XXXVI ketal, dl-endo-6-(1,2-dihydroxy-4-phenylbutyl)-bicyclo[3.1.0]hexan-3-one acetonide.
c. To prepare the formula-XXXVII compound, the ketal above is alkylated following the procedure of Example 1-B, but replacing methyl m-(chloromethyl)phenoxyacetate with methyl 9-chloro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-trans-7-nonenoate (Preparation 9, above), thereby yielding the title compound.
Following the procedures of Example 9, the formula-XXXVII compound is transformed via the formula-XXXVIII and -XXXIX compounds to the corresponding formula-XL PGE-type compound.
EXAMPLE 13
9-[Endo-6-(1,2-dihydroxy-2-methylheptyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-cis-7-nonenoic Acid Acetonide (Formula-LXXX, Chart G: G is n-pentyl; J' is ##SPC132##
R 9 and R 26 are hydrogen; R 2 , R 11 , and R 12 are methyl; and ˜ is alpha and endo.
Refer to Chart G. A solution of sodium borohydride (1.5 g.) in 10 ml. of water is added with stirring to a solution of formula-LXXVI dl-methyl 9-[endo-6-(1,2-dihydroxy-2-methylheptyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-cis-7-nonenoate acetonide (5.0 g.) in 110 ml. of absolute ethanol at 0° C. The mixture is stirred for 2.5 hrs. at 0° to 5° C. Then, 40 ml. of acetone is added, and, after 5 min., the mixture is evaporated under reduced pressure. The residue is extracted with dichloromethane, and the extract is washed successively with dilute hydrochloric acid and brine, dried, and concentrated to the formula-LXXVII compound, dl-methyl 9-[endo-6-(1,2-dihydroxy-2-methylheptyl)-3-hydroxybicyclo-[3.1.0]hex-2.alpha.-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-cis-7-nonenoate acetonide.
This formula-LXXVII cyclic ketal hydroxy ester is dissolved in a mixture of methanol (100 ml.) and 45% aqueous potassium hydroxide solution (30 ml.), and the solution is stirred under nitrogen at 25° C. for 15 hrs. Two volumes of water are then added, and the mixture is acidified with cold hydrochloric acid and then extracted with a mixture of dichloromethane and diethyl ether (1:3). The extract is washed with brine, dried, and concentrated to the formula-LXXVIII compound, dl-9-[endo-6-(1,2-dihydroxy-2-methylheptyl)-3-hydroxybicyclo[3.1.0]hex-2.alpha.-yl]-there are obtained the corresponding formula-LXXVII, LXXVIII, and LXXX compounds.
EXAMPLE 14
dl-7-[Endo-6-(1-heptenyl)-3-oxobicyclo[3.1.0]-hex-2α-yl]-3-oxa-4,7-inter-o-phenylene-5,6-dinor-heptanoic Acid (Formula-LXXXVI, Chart H: G is n-pentyl; Z' is ##SPC133##
R 2 , r 9 , and R 26 are hydrogen; and ˜ is alpha and endo).
Refer to Chart H. Following the procedure of Example 13, the formula-LXXXII compound, dl-ethyl 7-[endo-6-(1-heptenyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-4,7-intero-phenylene-5,6-dinor-heptanoate is reduced with sodium borohydride to the formula-LXXXIII compound, dl-ethyl 7-[endo-6-(1-heptenyl)-3-hydroxybicyclo[3.1.0]hex-2α-yl]-3-oxa-4,7-inter-o-phenylene-5,6-dinor-heptanoate. That hydroxy ester is then saponified as described in Example 13 to the formula-LXXXIV compound, dl-7-[endo-6-(1-heptenyl)-3-hydroxybicyclo[3.1.0]hex-2α-yl]-3-oxa-4,7-intero-phenylene-5,6-dinor-heptanoic acid. That hydroxy acid is then oxidized as described in Example 13 to the title compound.
Following the procedure of Example 14 but substituting for that formula-LXXXII compound, the formula-LXXXII compound of Example 10, viz. dl-methyl 7-[endo-6-(cis-4-phenyl-1-butenyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7inter-m-phenylene-4,5,6-trinor-7-nonynoate, there is obtained on reduction the corresponding formula-LXXXIII compound, dl-methyl-7-[endo-6-(cis-4-phenyl-1-butenyl)-3-hydroxybicyclo[ 3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate; there is likewise obtained on saponification the corresponding formula-LXXXIV compound, dl-7-[endo-6-(cis-4-phenyl-1-butenyl)-3-hydroxybicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoic acid; and there is likewise obtained on oxidation the corresponding formula-LXXXVI compound, dl-7-[endo-6-(cis-4-phenyl-1-butenyl)-3-oxabicyclo-[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoic acid.
Following the procedure of Example 14, but using in place of the formula-LXXXII 3-oxobicyclo[3.1.0]hexane ester, each of the specific formula-LXXXII endo and exo, alpha and beta, saturated and acetylenic esters described in and following the Examples 1, 6, and 10 is reduced with sodium borohydride to give the corresponding formula-LXXXIII 3-hydroxy-bicyclo[3.1.0]hexane ester. That hydroxy ester is then saponified as described in Example 13 to the corresponding formula-LXXXIV 3-hydroxybicyclo-[3.1.0]hexane acid. That hydroxy acid is then oxidized as described in Example 13 to the corresponding formula-LXXXVI 3-oxobicyclo[3.1.0]hexane acid.
EXAMPLE 15
dl-15-Dehydro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α Methyl Ester (Formula-XCI, Chart J: E' is trans --CH=CH--, G is n-pentyl, J' is ##SPC134##
R 1 is methyl, R 26 is hydrogen, and ˜ is alpha).
Refer to Chart J. A solution of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α methyl ester (Example 4, about 0.5 g.) in 24 ml. of dioxane is stirred at 50° C. under nitrogen and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (0.37 g.) is added. The mixture is stirred at 50° C. for 24 hrs., cooled to room temperature, and filtered. The filter cake is washed with tetrahydrofuran, and the filtrate and wash are combined and concentrated under reduced pressure. The residue is taken up in dichloromethane and washed with brine, then dried over sodium sulfate and concentrated under reduced pressure. The residue is chromatographed over 90 g. of silica gel wet-packed in 8% ethanol in dichloromethane, eluting with 300 ml. of 2%, 300 ml. of 3%, 225 ml. of 7.5% and 245 ml. of 10% ethanol in dichloromethane, taking 15-ml. fractions. Fractions shown by TLC to contain the desired product are combined and concentrated to the title compound.
EXAMPLE 16
dl-15-Methyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α Methyl Ester (Formula-XX: C g H 2g g and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU71## R 1 is methyl, and ˜ is alpha).
Refer to Chart J. A solution of 0.413 g. of dl-15-dehydro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α methyl ester (Example 15, about 0.4 g.), hexamethyldisilazane (3 ml.) and trimethylchlorosilane (0.5 ml.) in 20 ml. of tetrahydrofuran is allowed to stand at about 25° C. for 20 hrs. The mixture is filtered and the filtrate is concentrated under reduced pressure. Xylene (10 ml.) is added to the residue and removed by concentration under reduced pressure. The residue is dissolved in anhydrous ether and 110% of the theoretical amount of 3 M methyl magnesium bromide in ether is added. The mixture is allowed to stand 20 min. at about 25° C. and poured into 100 ml. of saturated aqueous ammonium chloride. The ether layer is separated, the aqueous layer is extracted with ether, and the ether extracts are combined and washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue is dissolved in 300 ml. of ethanol and 30 ml. of water containing 3 drops of glacial acetic acid, and the mixture is stirred for 2 hrs. at about 25° C. The mixture is concentrated under reduced pressure to an aqueous residue and the residue is extracted with dichloromethane. The dichloromethane extract is concentrated under reduced pressure to give a residue which is chromatographed over 60 g. of silica gel wet-packed in 8% ethanol in dichloromethane, eluting with 200 ml. of 5% and 800 ml. of 10% ethanol in dichloromethane and taking 10-ml. fractions. Fractions shown by TLC to contain the desired product are combined and concentrated to yield the title compound. Other fractions yield the 15-epimer.
Likewise, using the corresponding 3-oxa-4,7-inter-o-phenylene-5,6-dinor-PGF 1 .sub.α or PGF 1 .sub.β compound instead of the above oxa-phenylene compounds, there are obtained the corresponding 15-dehydro PGF 1 .sub.α or PGF 1 .sub.β-type compounds, and finally the dl-15-methyl-3-oxa-4,7-inter-o-phenylene-5,6-dinor-PGF 1 .sub.α or -PGF 1 .sub.β ethyl esters and their 15-epimers.
EXAMPLE 17
dl-13,14-Dihydro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 Methyl Ester (Formula XIX C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU72## R 1 is methyl, and ˜ is alpha).
Refer to Chart B. A solution of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 methyl ester (Example 3, 100 mg.) in 10 mg. of ethyl acetate is shaken with hydrogen at about one atmosphere pressure at 25° C. in the presence of 5% rhodium on charcoal (15 mg.). After approximately one equivalent of hydrogen is absorbed, the hydrogenation is stopped, and the catalyst is removed by filtration. The filtrate is concentrated, aand the residue is chromatographed on 25 g. of silica gel, eluting with 50-100% ethyl acetate gradient in Skellysolve B. Those fractions shown by TLC to contain the desired product free of the starting product and hydrogenolysis products are combined and concentrated to the title compound.
Following the procedure of Example 17, dl-3-oxa-3,7-m-phenylene-4,5,6-trinor-PGE 1 methyl ester is reduced to dl-13,14-dihydro-3-oxa-3,7-m-phenylene-4,5,6-trinor-PGE 1 ethyl ester. Likewise, dl-3-oxa-4,7-o-phenylene-5,6-dinor-PGE 1 methyl ester is reduced to dl-13,14-dihydro-3-oxa-4,7-o-phenylene-5,6-dinor-PGE 1 methyl ester.
Also following the procedure of Example 17, dl-3-oxa-3,7-m-phenylene-4,5,6-trinor-PGE 2 , -trans-5,6-dehydro-PGE 1 , and -5,6-dehydro-PGE 2 are each reduced to dl-13,14-dihydro-3-oxa-3,7-m-phenylene-4,5,6-trinor-PGE 1 , using two equivalents of hydrogen for the first two reactions, and three equivalents of hydrogen for the third. Likewise, the corresponding dl-3-oxa-4,7-o-phenylene-5,6-dinor- compounds are reduced to dl-13,-14,-dihydro-3-oxa-4,7-o-phenylene-5,6-dinor-PGE 1 .
Also following the procedure of Example 17, the ethyl ester and the free acid form of the formula XVI-to -XVIII PGE compounds in their various spatial configurations are transformed to the corresponding 13,14-dihydro PGE 1 compound by catalytic hydrogenation, using equivalents of hydrogen appropriate to the degree of unsaturation of the reactant, i.e., one equivalent for the PGE 1 type, two equivalents for the PGE 2 type and trans-5,6-dehydro-PGE 1 type, and three equivalents for the 5,6-dehydro-PGE 2 type.
Also following the procedure of Example 17, dl-3-oxa-3,7-m-phenylene-4,5,6-trinor-PGF 1 .sub.α and its ethyl ester are reduced to dl--13,14-dihydro-3-oxa-3,7-m-phenylene-4,5,6-PGF 1 .sub.α and its ethyl ester, respectively.
Also following the procedure of Example 17, the ethyl ester and the free acid form of the formula-XX to -XXII PGF compounds in their various spatial configurations are transformed to the corresponding 13,14-dihydro PGF 1 301 or PGF 1 .sub.β compound by catalytic hydrogenation, using equivalents of hydrogen appropriate to the degree of unsaturation of the reactant.
EXAMPLE 18
dl-13,14-Dihydro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 (Formula-XXVII: C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU73## R 1 is hydrogen, and ˜ is alpha).
Refer to Chart B. A suspension of disodium azodiformate (50 mg.) in 5 ml. of absolute ethanol is added to a stirred solution of 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 (Example 5, 50 mg.) in 10 ml. of absolute ethanol under nitrogen at 25° C. The mixture is made acid with glacial acetic acid, and then is stirred under nitrogen at 25° C. for 8 hrs. The resulting mixture is concentrated under reduced pressure, and the residue is mixed with a mixture of diethyl ether and water (1:1). The diethyl ether layer is separated, dried, and concentrated to the title product.
following the procedure of Example 18, dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 methyl ester is reduced to dl-13,14-dihydro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 methyl ester.
Also following the procedure of Example 18, dl-3-oxa3,7-inter-m-phenylene-PGA 2 , -trans-5,6-dehydro-PGA 1 , and 5,6-dehydro-PGA 2 are each reduced to dl-13,14-dihydro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 , using amounts of the disodium azodiformate reactant appropriate to the degree of unsaturation of the reactant.
Also following the procedure of Example 18, the methyl ester and the free acid form of the formula-XVI to -XVIII PGE type compounds, the formula-XX to -XXII PGF type compounds, the formula-XXIV to -XXVI PGA type compounds, and the formula-XXVIII to -XXX PGB type compounds are transformed to the corresponding 13,14-dihydro PGE 1 , PGF 1 , PGA 1 , or PGB 1 type compound by diimide reduction, using amounts of disodium azodiformate reactant appropriate to the degree of unsaturation of the PGE, PGF, PGA, or PGB type reactant.
EXAMPLE 19
dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 Methyl Ester (Formula-XXIV: C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU74## R 1 is methyl, and ˜ is alpha).
Refer to Chart D. A solution of the formula-XXXIX bismesylate, dl-methyl 7-[endo-6-(1,2-dimesyloxyheptyl)-3-oxabicyclo[3.1.0]hex-2α-yl]-3-oxa-3,7-inter-m-phenylene4,5,6-trinor-heptanoate (Example 3, about 10 g.) in 75 ml. -inter-m-phenylene- of acetone is mixed with 10 ml. of water and 20 ml. of saturated aqueous sodium bicarbonate solution. The mixture is refluxed under nitrogen for 4 hrs. Then, the mixture is cooled, acidified with 5% hydrochloric acid, and extracted with ethyl acetate. The extract is washed with brine, dried, and concentrated to give the title product.
Following the procedure of Example 19, each of the bismesylates defined in Example 3 is transformed to the corresponding PGA-type ester, including the β,β,β-trichloroethyl esters. Thereafter, each of the β,β,β-trichloroethyl esters is transformed to the corresponding PGA-type free acid by the procedure of Example 23, below.
EXAMPLE 20
dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGB 1 (Formula-XXVIII: C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU75## R 1 is hydrogen, and ˜ is alpha).
Refer to Chart A. A solution of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 (200 mg.) in 100 ml. of 50% aqueous ethanol containing about one gram of potassium hydroxide is kept at 25° C. for 10 hrs. under nitrogen. Then, the solution is cooled to 10° C. and neutralized by addition of 3 N. hydrochloric acid at 10° C. The resulting solution extracted repeatedly with ethyl acetate, and the combined ethyl acetate extracts are washed with water and then with brine, dried, and concentrated to give the title compound.
Following the procedure of Example 20, dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 is also transformed to the PGB 1 -type title compound.
Following the procedure of Example 20, each of the formula XVI-to -XIX PGE compounds and formula XXIV-to -XXVII PGA compounds are transformed to the corresponding PGB compounds.
EXAMPLE 21
dl-15-Methyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 Methyl Ester (Formula XVI: C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-pentyl; Q is ##EQU76## R 1 is methyl, and ˜ is alpha).
Refer to Chart I. A solution of dl-15-methyl-3-oxa3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α methyl ester (95 mg.) in 40 ml. of acetone is cooled to -10° C. To it is added 110% of the theoretical amount of Jones reagent (in the proportions of 21 g. of chromic anhydride, 60 ml. of water, and 17 ml. of concentrated sulfuric acid), precooled to 0° C., with vigorous stirring. After about 10 min., isopropyl alcohol (1 ml.) is added to the cold reaction mixture. After 5 min., the mixture is filtered and the filtrate is concentrated at reduced pressure, and the residue is mixed with 5 ml. of brine. The mixture is extracted repeatedly with ethyl acetate, and the combined extracts are washed with brine, dried with anhydrous sodium sulfate, and concentrated at reduced pressure. The residue is chromatographed on 20 g. of neutral silica gel, eluting with 50% ethyl acetate in Skellysolve B. Concentration of the eluates gives the title product.
Following the procedure of Example 21, there is substituted for the dl-15-methyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α methyl ester, the free acid, the propyl ester, the octyl ester, the cyclopentyl ester, the benzyl ester, the phenyl ester, the 2,4-dichlorophenyl ester, the 2-tolyl ester, of the β,β,β-trichloroethyl ester, there is obtained the corresponding dl-15-methyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 compound.
Following the procedure of Example 21, but substituting for the 15-methyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α methyl ester, the methyl ester of each of the 15-methyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.β, -PGF 2 .sub.α, -PGF 2 .sub.β, -5,6-dehydro-PGF 2 .sub.α, -5,6-dehydro-PGF 2 .sub.β, -dihydro-PGF 1 .sub.α, and -dihydro-PGF 1 .sub.β compounds in their various natural or 15-epi configurations and optical isomers is transformed to the corresponding PGE-type compound.
Following the procedure of Example 21, each of the various 15-alkyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α methyl ester compounds, including the 15-ethyl, 15 propyl, 15-butyl, and 15-substituted isomeric forms of propyl and butyl, is transformed to the corresponding PGE type compound.
Also following the procedure of Example 21, each of the 15-alkyl PGF-type acids and esters within the scope of formula-LXXXVIII (Chart I) is transferred to a 15-alkyl PGE-type acid or ester encompassed by formula-LXXXIX.
EXAMPLE 22
dl-15-Methyl-3-oxa-4,7-inter-o-phenylene-5,6dinor-PGA 1 Methyl Ester (Formula XXIV: C g H 2g is a valence bond, C p H 2p is methylene, C g H 2g and C p H 2p are in ortho relationship, G is n-pentyl, Q is ##EQU77## R 1 is methyl, and ˜ is alpha).
Refer to Chart K. A mixture of the formula-XCV 15-methyl-3-oxa-4,7-inter-o-phenylene-5,6-dinor-PGE 1 methyl ester (Example 21, 6 mg.), dicyclohexylcarbodiimide (20 mg.), copper (II) chloride dihydrate (2 mg.), and diethyl ether (2 ml.) is stirred under nitrogen at 25° C. for 16 hrs. Then, additional dicyclohexylcarbodiimide (20 mg.) is added, and the mixture is stirred an additional 32 hrs. at 25° C. under nitrogen. The resulting mixture is filtered, and the filtrate is concentrated under reduced pressure. The residue is chromatographed by preparative thin layer chromatography with the A-IX system to give the title compound.
Following the procedure of Example 22, but substituting for the oxa-phenylene PGE 1 compound, the methyl esters of dl-15-methyl-3-oxa-4,7-inter-o-phenylene-5,6-dinor-PGE 2 , -5,6-dehydro-PGE 2 , and -dihydro-PGE 1 , there are obtained the corresponding formula-XCVI compounds, viz., the methyl esters of dl-15-methyl 3-oxa-4,7-inter-o-phenylene-5,6-dinor-PGA 2 , -5,6-dehydro-PGA 2 , and -dihydro-PGA 1 .
Also following the procedure of Example 22, but substituting for the phenyl-substituted PGE 1 compound, the methyl esters of dl-15-methyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 , -PGE 2 , -5,6-dehydro-PGE 2 , and -dihydro-PGE 1 , there are obtained the corresponding formula-XCVI compounds, viz., the methyl esters of dl-15-methyl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 , -PGA 2 , -5,6-dehydro-PGA 2 , and -dihydro-PGA 1 .
Also following the procedure of Example 22, each of the formula-XCV (Chart K) compounds defined above in Example 21 is transformed to the corresponding formula-XCVI compound.
EXAMPLE 23
dl-3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 (Formula XVI: C g H 2q and C p H 2p are valence bonds in metal relationship, G is n-pentyl, Q is ##EQU78## R 1 is hydrogen, and ˜ is alpha).
Zinc dust (420 mg.) is added to a solution containing dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 β,β,β-trichloroethyl ester (100 mg.) in 5 ml. of a mixture of acetic acid and water (9:1 v/v). This mixture is stirred under nitrogen 2 hrs. at 25° C. Ethyl acetate (4 volumes) is then added, followed by addition of 1 N. hydrochloric acid (one volume). The ethyl acetate later is separated, washed with water and then with brine, dried, and evaporated. The residue is chromatographed on 15 g. of acidwashed silica gel (Silicar CC4), being eluted with 100 ml. of 50%, 100 ml. of 80%, and 200 ml. of 100% ethyl acetate in Skellysolve B, collecting 20-ml. fractions. The fractions containing the desired product and no starting material or dehydration products as shown by TLC are combined and concentrated to the title compound.
Following the procedure of Example 23, each of the β,β,β-tribromoethyl, -triiodoethyl, β,β-dibromoethyl, -diiodoethyl, and the β-iodoethyl esters of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 is converted to the free acid of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 by reaction with zinc dust and acetic acid.
Following the procedure of Example 23, the β,β,βtrichloroethyl ester of dl-15-methyl-3-oxa-3,5-inter-m-phenylene-4-nor-PGE 2 following Example 9 above is converted to the respective free acid compound using zinc dust with either propionic, butyric, pentanoic, or hexanoic acid instead of acetic acid.
Following the procedure of Example 23, the β,β,β-trichloroethyl ester of each of the PGE, PGF, PGA, and PGF type compounds represented by formulas XVI-XXXV in their various structural configurations and optical isomers is treated with zinc dust and acetic acid to obtain the corresponding free acid form of the compound. The esters are prepared by the procedures disclosed herein, using as intermediates formula-XXXVII cyclic ketals or formula-XLIV or -LXX olefins wherein R 10 is haloethyl, e.g., β,β,β-trichloroethyl. These intermediates are prepared either by alkylation of the respective formula-XXXVI cyclic ketal (Chart D) or formula-XLIII or -LXIX olefin (Charts E and F) with the appropriate alkylating agent wherein R 10 is haloethyl, or by the transformation of the alkylated cyclic ketal or olefin by the steps shown in Charts G and H using procedures disclosed herein, yielding intermediates LXXIX, LXXXI, LXXXV, or LXXXVII.
EXAMPLE 24
dl-3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α and -PGF 1 .sub.β (Formula XX; C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU79## R 1 is hydrogen, and ˜ is alpha or beta).
A solution of 146 mg. of dl-3-oxo-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α ethyl ester in a mixture of 4.5 ml. of methanol and 1.5 ml. of water is cooled to 5° C. and 0.6 ml. of 45% aqueous potassium hydroxide is added. The mixture is allowed to stand 3.5 hrs. at 25° C., then is diluted with 75 ml. of water and extracted once with ethyl acetate to remove any neutral material. The aqueous layer is separated, made acid with dilute hydrochloric acid and extracted 4 times with ethyl acetate. The extracts are combined and washed 3 times with water, once with brine, dried over sodium sulfate, and concentrated to give the PGF 1 .sub.α -type title compound.
Following the procedure of Example 24, the methyl ester of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinorPGF 1 .sub.β is transformed to the free acid, i.e. the formula-XX PGF 1 .sub.β -type title compound.
Following the procedure of Example 24, the methyl or ethyl esters of the various oxa-phenylene PGF-type compounds and their isomers are transformed to the corresponding free-acid oxa-phenylene PGF-type compounds.
EXAMPLE 25
dl-3-Oxa-3,5-inter-m-phenylene-4-nor-PGF 2 .sub.α Methyl Ester (Formula XXI: C j H 2j and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU80## R 1 is methyl, R 3 and R 4 are hydrogen, and ˜ is alpha).
Refer to Chart C. dl-5,6-Dehydro-3-oxa-3,5-inter-m-phenylene-4-nor-PGF 2 .sub.α methyl ester (200 mg.) in pyridine (4 ml.) and methanol (10 ml.) is hydrogenated in the presence of a 5%-palladium-on-barium sulfate catalyst (200 mg.) at 25° and atmospheric pressure. The reaction is terminated when slightly more than one equivalent of hydrogen is absorbed. The mixture is filtered and evaporated. Ethyl acetate is added and residual pyridine is removed by addition of ice and 3 N. hydrochloric acid. The ethyl acetate layer is washed with 1 N. hydrochloric acid and then with brine, dried, and concentrated to yield the title product.
Following the procedure of Example 25, the 5,6-dehydro oxa-phenylene PGF 2 compounds following Example 4 are reduced to the corresponding PGF 2 compounds. Likewise, the 5,6-dehydro oxa-phenylene PGE, PGA, and PGB compounds disclosed herein are reduced to the corresponding PGE 2 , PGA 2 , and PGB 2 compounds.
EXAMPLE 26
dl-β,β,β-Trichloroethyl 9-[endo-6-(1,2-dihydroxy-2-methylheptyl)-3-hydroxybicyclo[3.1.0]-hex-2.alpha.-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6trinor-cis-7-nonenoate Acetonide (Formula LXXIX, Chart G: G is n-pentyl, J' is cis ##SPC135##
haloethyl is β,β,β-trichloroethyl, R 2 , R 11 , and R 12 are methyl, R 9 and R 26 are hydrogen, and ˜ is alpha and endo).
Refer to chart G. Successively, β,β,β-trichloroethanol (25 ml.), pyridine (15 ml.), and dicyclohexylcarbodiimide (4.0 g.) are added to a solution of formula-LXXVIII compound dl-9-[endo-6-(1,2-dihydroxy-2-methylheptyl)-3-hydroxybicyclo[3.1.0]hex-2.alpha.-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-cis-7-nonenoic acid acetonide (Example 13, 2.0 g.) in 100 ml. of dichloromethane. This mixture is stirred 3 hrs. under nitrogen at 25° C. Water (50 ml.) is then added, and the mixture is stirred 10 min. The dichloromethane is concentrated under reduced pressure, and the residue is extracted repeatedly with ethyl acetate. The combined extracts are washed with ice-cold 3 N. hydrochloric acid. Then, the extracts are washed successively with aqueous sodium bicarbonate solution and brine, dried, and concentrated under reduced pressure. The residue is chromatographed on 600 g. of silica gel, eluting with 10 l. of a 20-100% ethyl acetate-Skellysolve B gradient, collecting 50ml. fractions. The middle fractions which show a product free of starting materials on TLC are combined and concentrated under reduced pressure to give the title compound.
Following the procedure of Example 26, but using in place of the formula-LXXVIII 3-hydroxybicyclo[3.1.0]hexane acid acetonide, each of the specific endo and exo, alpha and beta, saturated and unsaturated formula-LXXVIII hydroxy acid ketals defined after Example 13, there are obtained the corresponding β,β,β-trichloroethyl esters of those 3-hydroxybicyclo[3.1.0]hexane acids.
Following the procedure of Example 26, but using in place of the formula-LXXVIII 3-hydroxybicyclo[3.1.0]hexane acid ketal, each of the specific formula-LXXX 3-oxo-acid ketals defined after Example 13, there are obtained the corresponding formula-LXXXI β,β,β-trichloroethyl esters of those 3-oxo-acid ketals.
Following the procedure of Example 26 but using in place of the formula-LXXVIII 3-hydroxy-acid ketal, each of the specific formula-LXXXIV (Chart H) 3-hydroxy and formula-LXXXVI 3-oxo acids defined after Example 14, there are obtained the corresponding formula-LXXXV and formulaLXXXVII β,β,β-trichloroethyl esters of those acids, respectively.
Following the procedures of Examples 3 and 9, each of the formula-LXXXI cyclic ketal haloethyl esters of Example 26 is transformed to the corresponding formula-XL (Chart D) 3-oxa or 4-oxa phenyl-substituted PGE 1 β,β,β-trichloroethyl ester. Thence, following the procedure of Example 23, each of the esters is transformed to the oxaphenylene PGE 1 acid compound wherein R 10 of formula-XL is replaced with hydrogen.
Following the procedure of Examples 2 and 3 each of the formula-LXXXVII olefin haloethyl esters of Example 26 is transformed to the corresponding formula-XLVII (Chart E) oxa-phenylene PGE 1 β,β,β-trichloroethyl ester. Thence, following the procedure of Example 23, each of the esters is transformed to the corresponding PGE 1 -type acid compound wherein R 10 of formula-XL is replaced with hydrogen.
EXAMPLE 27
dl-3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 Methyl Ester (Formula XXIV: C g H 2g and C p H 2p are valence bonds in meta relationship, G is n-pentyl, Q is ##EQU81## R 1 is methyl, and ˜ is alpha).
A solution of diazomethane (about 50% excess) in diethyl ether (25 ml.) is added to a solution of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-pGA 1 (Example 5, 50 mg.) in 25 ml. of a mixture of methanol and diethyl ether (1:1). The mixture is allowed to stand at 25° C. for 5 min. Then the mixture is concentrated to give the title compound.
Following the procedure of Example 27, each of the other specific phenyl-substituted PGB type, PGA type, PGE type, and PGF type free acids defined above is converted to the corresponding methyl ester.
Also following the procedure of Example 27, but using in place of the diazomethane, diazoethane, diazobutane, 1-diazo-2-ethylhexane, and diazocyclohexane, there are obtained the corresponding ethyl, butyl, 2-ethylhexyl, and cyclohexyl esters of 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 . In the same manner, each of the other specific phenyl-substituted PGB type, PGA type, PGE type, and PGF type free acids defined above is converted to the corresponding ethyl, butyl, 2-ethylhexyl, and cyclohexyl esters.
EXAMPLE 28
dl-3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 Methyl Ester Diacetate. ,
Acetic anhydride (5 ml.) and pyridine (5 ml.) are mixed with dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 methyl ester (Example 3, 20 mg.), and the mixture is allowed to stand at 25° C. for 18 hrs. The mixture is then cooled to 0° C., diluted with 50 ml. of water, and acidified with 5% hydrochloric acid to pH 1. That mixture is extracted with ethyl acetate. The extract is washed successively with 5% hydrochloric acid, 5% aqueous sodium bicarbonate solution, water, and brine, dried and concentrated to give the title compound.
Following the procedure of Example 28 but replacing the acetic anhydride with propionic anhydride, isobutyric anhydride, and hexanoic acid anhydride, there are obtained the corresponding dipropionate, diisobutyrate and dihexanoate derivatives of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 methyl ester.
Also following the procedure of Example 28, but replacing the 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 compound with dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α and -PGF 1 .sub.β, and dl-15-methyl-3-oxa13,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub..alpha. and -PGF 1 .sub.β, there are obtained the corresponding triacetate derivatives of the 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF compounds.
Also following the procedure of Example 28, each of the phenyl-substituted PGE type, PGF type, PGA type, and PGB type esters and free acids defined above is transformed to the corresponding acetates, propionates, isobutyrates, and hexanoates, the PGE-type derivatives being dicarboxyacylates, the PGF-type derivatives being tricarboxyacylates, and the PGA-type and PGB-type derivatives being monocarboxyacylates.
EXAMPLE 29
dl-3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 Sodium Salt.
A solution of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 (Example 23, 100 mg.) in 50 ml. of a water-ethanol mixture (1:1) is cooled to 5° C. and neutralized with an equivalent amount of 0.1 N, aqueous sodium hydroxide solution. The neutral solution is concentrated to give the title compound.
Following the procedure of Example 29 but using potassium hydroxide, calcium hydroxide, tetramethylammonium hydroxide, and benzyltrimethylammonium hydroxide in place of sodium hydroxide, there are obtained the corresponding salts of dl-3-oxa-3,7l -inter-m-phenylene-4,5,6-trinor-PGE 1 .
Also following the procedure of Example 29 each of the phenyl-substituted PGE type, PGF type, PGA type, and PGB type acids defined above is transformed to the sodium, potassium, calcium, tetramethylammonium, and benzyltrimethylammonium salts.
The various Preparations and Examples given above describe the preparation of racemic intermediates and final products. Each of the intermediates and final products named and defined above is also obtained in each of the enantiomeric forms, d and l, by resolution that compound or by resolution of an intermediate used to prepare that compound. For example, natural configuration 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 free acid is prepared by resolution of dl-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGA 1 free acid (Example 5) or by dehydration as in Example 5 of optically active 3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 free acid with the same absolute configuration. These resolutions are carried out by procedures known in the art, and may be used to obtain prostaglandin-like materials having the spatial configuration of the natural prostaglandins, as typified by the following Examples 30-32.
EXAMPLE 30
Natural Configuration 3-oxa-3,5-inter-m-phenylene-4-nor-PGE 2 and PGF 2 .sub.α Methyl Esters (Formula-XVII and -XXI: wherein C j H 2j and C p H 2p following the valence bonds in meta relationship, G is n-pentyl, Q is ##EQU82## R 1 is methyl; R 3 and R 4 are hydrogen; and ˜ is alpha).
The process shown in Chart D is used to prepare the PGE 2 -type compound first. formula-XXXVIII formula-XXXVII cyclic ketal intermediate wherein formula-XVII is n-pentyl; J' is ##SPC136## PFG.sub. -Oxa-
R 2 , r 9 , and R 26 are hydrogen; R 10 , R 11 , and R 12 are methyl; and ˜ is endo and alpha is prepared following the procedures of Example 9.
The formula-XXXVII compound is resolved as its optical isomers by the method of Corey et al., J. Am. Chem. Soc. 84, 2938 (1962), by reacting this keto compound with optically active L(+)-2,3-butanedithiol in the presence of p-toluene-sulfonic acid. The diastereomeric ketals are completely resolved on a preparative chromatographic column, and are then hydrolyzed separately, following the procedure of Example 9, to the formula-XXXVII dihydroxy compounds. Transformation to the formula-XVII PGE 2 -type compounds is accomplished by the procedures of Example 3. Of the separate diastereoisomers, one corresponds to the configuration of natural PGE 2 and the other to its enantiomer. Conversion of the PGE 2 -type compound having the configuration of the natural product to the PGF 2 .sub.α -type methyl ester is done by borohydride reduction following the procedure of Example 4. The natural configuration-PGF 2 .sub.α -type free acid is formed from the methyl ester by saponification, following the procedure of Example 24.
EXAMPLE 31
Natural Configuration 3-oxa-3,5-inter-o-phenylene-4-nor-PGE 1 Methyl Ester (Formula XVI: C g H 2g is ethylene; C p H 2p is a valence bond in ortho relationship to C g H 2g , G is n-pentyl, Q is ##EQU83##
R 1 is methyl, and ˜ is alpha).
to Chart E. A. Methyl 7-[endo-6-(1-heptenyl)-3-oxobicyclo-[3.1.0]hex-2α-yl]-3-oxa-3,5-inter-o-phenylene-4-nor-heptanoate (Formula-XLIV, Chart E: G is n-pentyl; R 2 , R 9 , and R 26 are hydrogen; R 10 is methyl; Z' is ##SPC137##
and ˜ is alpha and endo).
1. Methyl 2-(3-hydroxypropyl)phenoxyacetate. To a solution of potassium t-butoxide (11.2 g.) in 150 ml. of dry tetrahydrofuran at 0°-5° C. is added with stirring 3-(o-hydroxyphenyl)propanol (15.2 g.) followed in a few minutes by methyl bromoacetate (20 g.). The cooling bath is removed and the mixture is stirred at ambient temperature until the reaction mixture becomes essentially neutral. The mixture is concentrated in vacuo at 30° C. and the residue is shaken with ether and water. The organic layer is washed with dilute potassium hydroxide solution, water, brine, and is dried over sodium sulfate and then concentrated in vacuo. The residue is distilled in a high vacuum to afford methyl 2-(3-hydroxypropyl)phenoxyacetate. 2. Methyl 2-(3-chloropropyl)phenoxyacetate. A mixture of methyl 2-(3-hydroxypropyl)phenoxyacetate (step A-1, 25 g.) and thionyl chloride (20 ml.) is heated to reflux for 1-2 hrs. The excess thionyl chloride is removed in vacuo and the residue is distilled in a high vacuum to afford methyl 2-(3-chloropropyl)phenoxyacetate. 3. Methyl 2-(3-iodopropyl)phenoxyacetate. A mixture of methyl 2-(3-chloropropyl)phenoxyacetate (step A-2, 24.3 g.), acetone (250 ml.) and sodium iodide (30 g.) is heated to reflux with stirring for about 40 hrs. The mixture is cooled, filtered and the filtrate is concentrated in vacuo at about 30° C. The residue is diluted with ether and the solution is washed with water, dilute sodium thiosulfate solution, brine and is dried over magnesium sulfate and then concentrated in vacuo. The product, methyl 2-(3-iodopropyl)phenoxyacetate, is used directly in the next step. 4. Following the procedure of Example 1-B, but replacing the methyl m-(chloromethyl)phenoxyacetate with methyl 2-(3-iodopropyl) phenoxyacetate (step A-3, 18 g.) and allowing the alkylation reaction to proceed for about 5 min. before acidification with hydrochloric acid, there is obtained the desired formula-XLIV methyl 7-]endo-6-(1-heptenyl)-3-oxobicyclo[3.1.0]hex-2α-yl]-3-oxa-3,5-inter-o-phenylene-4-nor-heptanoate.
Following the procedure of Example 30, the above racemic formula-XLIV compound is resolved as two optically active isomers. These are both transformed by the subsequent steps of this example to the formula-XVI PGE 1 -type compounds, one of which corresponds to the configuration of natural PGE 1 and the other to its enantiomer.
B. Methyl 7-[endo-6-(1,2-dihydroxyheptyl)-3-oxo-bicyclo[3.1.0]hex-2α-yl]-3-oxa-3,5-inter-o-phenylene-4-nor-heptanoate (Formula-XLV, Chart E: G' is n-pentyl; R 2 , R 9 , and R 26 are hydrogen; R 10 is methyl; Z' is ##SPC138##
and ˜ is alpha and endo). To a solution of methyl 7-[endo-6-(1-heptenyl)-3-oxobicyclo[3.1.0]-hex-2α-yl]-3-oxa-3,5-inter-o-phenylene-4-nor-heptanoate (step A, above, 1.8 g.) in 30 ml. of tetrahydrofuran at 50° is added, with stirring, osmium tetroxide (200 mg.) followed by potassium chlorate (1.2g.) and 15 ml. of water. The reaction mixture is maintained at 50° for 2 hrs., cooled, the tetrahydrofuran is removed, and the aqueous phase is extracted with dichloromethane. The organic layer is dried and concentrated and the residue is chromatographed on 200 g. of silica gel. The column is eluted with 1 l. of 35% ethyl acetate-benzene and 1 l. of 40% ethyl acetate-benzene, collecting 30-ml. fractions. Those fractions containing the formula-XLV compound, in its isomeric erythro and threo forms free of starting material and impurities, are combined and concentrated.
C. Title compound. To a solution of the formula-XLV dihydroxy compound (step B, above, 0.8 g.) in 10 ml. of pyridine, cooled to 0°, is added 1.2 ml. of methane-sulfonyl chloride. The reaction mixture is stirred for 2 hrs. and 20 g. of ice is added. The mixture is extracted with ether-dichloromethane (1:1) and the organic layer is washed successively with dilute hydrochloride acid, water, saturated aqueous sodium bicarbonate, and brine, dried, and concentrated. The residue, containing the bismesylate, is treated with 15 ml. of acetone and 10 ml. of water and stirred for 8-16 hrs. at 25°. The acetone is removed in vacuo and the remaining solution is extracted with dichloromethane. The extract is dried and concentrated and the residue is chromatographed on 150 g. of silica gel using 500 ml. ethyl acetate followed by 3% methanol ethyl acetate as eluting solvent while collecting 30-ml. fractions. Those fractions containing the formula-XLVII product, free of starting material and impurities, are combined and concentrated to give the title compound; principle NMR spectral peaks at 6.57-7.3 (multiplet); 5.42-5.65 (multiplet); 4.60 (singlet) and 3.76 (singlet) δ.
EXAMPLE 32
Natural Configuration 3-Oxa-3,5-inter-o-phenylene-4-nor-PGF 1 .sub.α Methyl Ester (Formula-XX: C g H 2g is ethylene, C p H 2p is a valence bond in ortho relationship to C g H 2g , G is n-pentyl, Q is ##EQU84## R 1 is methyl, and ˜ is alpha for the carboxyl-containing moiety and for the ring hydroxyl).
Refer to Chart A. Following the procedure of Example 4, the formula-XVI PGE 1 -type compound of Example 31 is transformed to the title compound; principle NMR spectral peaks at 6.57-7.3 (multiplet); 5.33-5.56 (multiplet); 4.62 (singlet) and 3.75 (singlet) δ.
EXAMPLE 33
dl-3-Oxa-3,5-inter-m-phenylene-4-nor-PGE 3 Methyl Ester (Formula-XXXII; C j H 2j and C p H 2p are valence bonds in meta relationship, C n H 2n is methylene, Q is ##EQU85## R 1 is methyl, R 5 is ethyl, and ˜ is alpha) and dl-15-Beta-3-oxa-3,5-inter-m-phenylene-4-nor-PGE 3 Methyl Ester ##EQU86##
a. Refer to Chart F. Following the procedure of Preparation 4b, a solution of 100 g. of endo-bicyclo-[3.1.0 ]hexan-3-ol-6-carboxaldehyde 3-tetrahydropyranyl ether in 200 ml. of benzene is reacted with 250 g. of (hex-3-ynyl)triphenylphosphonium bromide (Axen et al., Chem. Comm. 1970, 602) in 3 l. of benzene at about -15° C. The mixture is warmed to 70° C. for 2.5 hours., cooled and filtered. The crude product is hydrolyzed to the 3-hydroxy compound and then oxidized to the 3-oxo ketone with Jones reagent. The desired fromula-LXIX intermediate is isolated after silica gel chromatography.
b. There is next prepared the formula-LXX compound by alkylation. Following the procedures of Example 1-B, the product of step a above is reacted with methyl 9-chloro-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate (Preparation 7) to yield 7-[endo-6-(cis-1-hepten-4-ynyl)-3-oxobicyclo[3.1.0]-hex-2α-yl]-3-oxa-3,7-inter-m-phenylene-4,5,6-trinor-7-nonynoate.
c. Glycol LXXI is next prepared, employing the product of step b and following the procedures of Example 2. Without separating the isomeric glycols, the bismesylate corresponding to formula-LXXII is then prepared following the procedures of Example 3. Thereafter, following hydrolysis of the bismesylate by the procedures of Example 3, the bisdehydro E 3 type compound corresponding to formula-LXXIII is recovered. Silica gel chromatography yields the respective C-15 epimers.
d. Following the procedures of Preparation 8, each of the C-15 epimers of step C above is hydrogenated to yield the corresponding title compounds.
EXAMPLE 34
1-Bicyclo[3.1.0]hex-2-ene-6-endocarboxaldehyde Neopentyl Glycol Acetal (Formula CIX : R 31 and R 32 taken together are --CH 2 --C(CH 3 ) 2 --CH 2 -- and ˜ is endo).
A mixture of 2,2-dimethyl-1,3-propanediol (900 g.), 5 l. of benzene and 3 ml. of 85% phosphoric acid is heated at reflux. To it is added, in 1.5 hr., a solution of optically active bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde (Prep.10, 500 g.) in one liter of benzene. Provision is made to take off azeotropically distilled water with a Dean-Stark trap. After 3 hr. the mixture is cooled and extracted with 2 liters off 5% sodium bicarbonate. The organic phase is dried over sodium sulfate and concentrated under reduced pressure. The resulting semisolid residue is taken up in methanol and recrystallized, using a total of 1200 ml. of methanol to which 600 ml. of water is added, then chilled to -13° C. to yield 300 g. of the title compound, m.p. 52°-55° C., and having NMR peaks at 0.66, 1.20, 0.83-2.65, 3.17-3.8, 3.96, and 5.47-5.88 δ, [α] D - 227° (C=0.8976 in methanol), and R f 0.60 (TLC on silica gel in 25% ethyl acetate in mixed isomeric hexanes). Further work-up of the mother liquors yields 50-100 g. of additional product.
Following the procedures of Example 34 but replacing the aldehyde with optically active bicyclo[3.1.0]hex-2-ene-6-exo-carboxaldehyde (see U.S. Pat. No. 3,711,515), there is obtained the corresponding formula-CIX acetal.
Following the procedures of Example 34 but using either the endo or exo form of the aldehyde and substituting for 2,2-dimethyl-1,3-propanediol one of the following glycols: ethylene glycol, 1,2-propanediol, 1,2-hexanediol, 1,3-butanediol, 2,3-pentanediol, 2,4-hexanediol, 2,4-octanediol, 3,5-nonanediol, 3,3-dimethyl-2,4-heptanediol, 4-ethyl-4-methyl-3,5-heptanediol, phenyl-1,2-ethanediol and 1-pentyl-1,2-propanediol, there are obtained the corresponding formula-CIX acetals.
EXAMPLE 35
d-8-(m-Acetoxyphenyl)-7-oxa-tricyclo-[4.2.0.0 2 ,4 ]octane-6-endo-carboxaldehyde Neopentyl Glycol Acetal (Formula CX: C p H 2p is a valence bond with attachment in the meta position, R 31 and R 32 taken together are --CH 2 --C(CH 3 ) 2 -CH 2 , R 39 is ##EQU87## and ˜ is endo).
Refer to Chart L, step (a). A solution of the formula-CIX l-bicyclo[3.1.0]hex-2-ene-6-endo-carboxaldehyde neopentyl glycol acetal (Example 34, 5.82 g.) and m-acetoxybenzaldehyde (1.64 g.) in 25 ml. of benzene is charged to a Pyrex Photolysis vessel equipped with an immersible water-cooled cold-finger and a fritted gas inlet tube. Dissolved oxygen is removed by bubbling nitrogen through the solution. The mixture is then irradiated at 350 nm. with a Rayonet Type RS Preparative Photochemical Reacter (The Southern New England Ultraviolet Co., Middletown, Conn.) equipped with six RUL 3500 A lamps. After 24 hr. the photolysate is concentrated under reduced pressure to a pale yellow oil, 10 g., which is subjected to silica gel chromatography. Elution with 10-70% ethyl acetate in Skellysolve B (mixture of isomeric hexanes) yields separate fractions of the recovered starting material and the formula-CX title compound, a pale yellow oil, 0.86 g., having NMR peaks at 0.68. 1.20, 0.8-2.5, 2.28, 2.99, 3.12-3.88, 3.48, 4.97-5.52, and 6.78-7.60 δ; infrared absorption bands at 3040, 2950, 2860, 2840, 1765, 1610, 1590, 1485, 1470, 1370, 1205, 1115, 1020, 1005, 990, 790, and 700 cm - 1 ; mass spectral peaks at 358, 357, 116, 115, 108, 107, 79, 70, 69, 45, 43, and 41; [α] D + 55° (C=0.7505 in 95% ethanol); and R f 0.18 (TLC on silica gel in 25% ethyl acetate in mixed isomeric hexanes).
Following the procedures of Example 35 but replacing the formula-CIX acetal with the formula-CIX compounds disclosed following Example 34, there are obtained the corresponding formula-CX compounds in their endo or exo forms and with corresponding exemplification of R 31 and R 32 .
Likewise following the procedures of Example 35 but replacing m-acetoxybenzaldehyde with aldehydes within the scope of formula CXIX above, as to C p H 2p , the attachment position of the phenyl ring, and the carboxyacyl group R 39 , or defined above, the corresponding formula-CX oxetanes are obtained wherein ˜ is endo or exo, and R 31 and R 32 correspond to the glycols employed after Example 34 above. Specifically, the following formula-CXIX aldehydes are employed: ##SPC139##
EXAMPLE 36
d-2-Exo-[m-(pivaloyloxy)benzyl]-3-exobicyclo[3.1.0]hexane-6-endo-carboxaldehyde Neopentyl Glycol Acetal (Formula CXII: C p H 2p is a valence bond with attachment in the meta position, R 31 and R 32 taken together are --CH 2 --C(CH 3 ) 2 --CH 2 --, R 43 is ##EQU88## and ˜ is endo).
(I). Refer to Chart L, steps (b) and (c). A mixture of lithium (0.25 g.) in 70 ml. of ethylamine is prepared at 0° C. and cooled to -78° C. A solution of the formula-CX d-8-(m-acetoxyphenyl)-7-oxa-tricyclo[4.2.0.0 2 ,4 ]-octane-6-endo-carboxaldehyde neopentyl glycol acetal (Example 35, 1.83 g.) in 10 ml. of tetrahydrofuran is added dropwise in about 5 min. After stirring at -78° C. for about 3.5 hr. the reaction is quenched with solid ammonium chloride and water-tetrahydrofuran. Unreacted lithium is removed, the mixture is warmed slowly to about 25° C., and ethylamine is removed. The residue is neutralized with dilute acetic acid, mixed with 200 ml. of brine, and extracted with ethyl acetate. The organic phase is washed with brine and a mixture of brine and saturated aqueous sodium bicarbonate (1:1), and dried over sodium sulfate. Concentration under reduced pressure yields the formula-CXI diol as a pale tan foamed oil, 1.64 g., having R f 0.03 (TLC on silica gel in 25% ethyl acetate in mixed isomeric hexanes).
(II). The product of part (I) is dissolved in 30 ml. of pyridine and treated with 1.5 ml. of pivaloyl chloride over a period of 22 hr. at about 25° C. The reaction mixture is mixed with water, then brine and extracted with ethyl acetate. The organic phase is washed successively with brine, water, saturated aqueous copper (II) sulfate, saturated aqueous sodium bicarbonate, and brine, and dried over sodium sulfate. Concentration under reduced pressure yields a residue, 2.53 g., which is subjected to silica gel chromatography to yield the formula-CXII title compound, 1.87 g., having NMR peaks at 0.71, 1.20, 1.33, 0.9-3.1, 3.28-4.00, 4.17, 4.7-5.2, and 6.77-7.53 δ; mass spectral peaks at 486, 485, 115, 73, 72, 57, 44, 43, 42, 41, 30, 29, 15; [α] D +10° (C=0.8385 in ethanol); and R f 0.50 (TLC on silica gel in 25% ethyl acetate in mixed isomeric hexanes).
EXAMPLE 37
d-2-Exo-(m-acetoxybenzyl)-3-exo-acetoxybixyclo]3.1.0]hexane-6-endo-carboxaldehyde Neopentyl Glycol Acetal (Formula CXII: C p H 2p is a valence bond with attachment in the meta position, R 31 and R 32 taken together are --CH 2 C(CH 3 ) 2 --CH 2 --, R 43 is ##EQU89## and ˜ is endo).
Following the procedure of Example 36-(II) but replacing pivaloyl chloride with acetic anhydride, and using 1.01 g. of the formula-CXI diol, there is obtained the title compound, 0.75 g., having NMR peaks at 0.72, 1.22, 1.98, 2.27, 0.8-3.0, 3.28-3.85, 4.17, 4.75-5.22, and 6.8-7.47 δ; mass spectral peaks at 402, 401, 115, 107, 73, 69, 45, 44, 43, 42, 41, 30;[α] D +7° (C=0.7060 in ethanol); and R f 0.66 (TLC on silica gel in 50% ethyl acetate in mixed isomeric hexanes).
EXAMPLE 38
2-Exo-[m-(pivaloyloxybenzyl]-3-exo-(pivaloyloxy)bicyclo[3.1.0]hexane-6-endo-carboxaldehyde (Formula CXIII: C p H 2p is a valence bond with attachment in the meta position, R 42 is ##EQU90## and ˜ is endo).
Refer to Chart L step (d). The formula-CXII acetal, i.e. d-2-exo-[m-pivaloyloxy)benzyl]-3-exo-(pivaloyloxy)-bicycly[3.1.0]hexane-6-endo-carboxaldehyde neopentyl glycol acetal (Example 36, 0.48 g.) is treated at 0° C. with 25 ml. of 88% formic acid for 4 hr. The mixture is diluted with 200 ml. of brine and extracted with ethyl acetate. The organic phase is washed with brine and saturated aqueous sodium bicarbonate, and dried over magnesium sulfate. Concentration under reduced pressure yields an oil, 0.55 g., which is subjected to silica gel chromatography. Elution with 5-15% ethyl acetate in Skellysolve B yields the formula-CXIII title compound as an oil, 0.37 g., having NMR peaks at 1.20, 1.33, 0.6-3.2, 5.1-5.5, 6.6-7.5, and 9.73 δ; and R f 0.50 (TLC on silica gel in 25% ethyl acetate in mixed isomeric hexanes).
EXAMPLE 39
2-exo-[m-(pivaloyloxy)benzyl]-3-exo-(pivaloyloxy)-6-endo-(cis-1-heptenyl)-bicyclo[3.1.0]hexane (Formula CXIV: C p H 2p is a valence bond with attachment in the meta position, G is n-pentyl, R 42 is ##EQU91##
R 2 is hydrogen, and ˜ is endo); and 2-Exo-(m-hydroxybenzyl)-3-exo-hydroxy-6-endo-(cis-1-heptenyl)bicyclo[3.1.0]hexane (Formula CXV : C p H 2p is a valence bond in the meta position, G is n-pentyl, R 2 and R 42 are hydrogen, and ˜ is endo).
(I). Refer to Chart L, steps (e) and (f). The Wittig ylid reagent is prepared in 10 ml. of benzene from n-hexyltriphenylphosphonium bromide (0.79 g.) and n-butyllithium (0.6 ml. of 2.32 M. solution in hexane) at about 25° C. for 0.5 hr. After the precipitated lithium bromdie has settled, the solution is removed and added to a cold (0° C.) slurry of the formula-CXIII aldehyde (Examples 38, 0.37 g.). After 15 min. there is added 1.0 ml. of acetone and the mixture is heated to 60° C. for 10 min. The mixture is concentrated under reduced pressure. The residue is washed with 10% ethyl acetate in Skellysolve B and these washings are concentrated to the formula-CXIV title compound, an oil, 0.33 g. having NMR peaks at 1.18, 1.33, 0.6-3.2, 4.5-6.0 and 6.67-7.62 δ; and R f 0.78 (TLC on silica gel in 25% ethyl acetate in Skellysolve B).
(II.) The above product of part (I) is transformed to the formula-CXV diol by treatment with sodium methoxide (2.5 ml. of a 25% solution in methanol) for 4 hr., followed by addition of 0.5 g. of solid sodium methoxide and further stirring for 15 hr. at 25° C., then at reflux for 6 hr. The mixture is cooled, mixed with 300 ml. of brine, and extracted with ethyl acetate. The organic phase is washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure to a residue, 0.27 g. The residue is subjected to silica gel chromatography, eluting with 25-35% ethyl acetate in Skellysolve B, to yield the formula-CXV title compound an an oil, 0.21 g., having NMR peaks at 0.87, 0.6-3.25, 3.88-4.35, 4.82-5.92, and 6.47-7.33 δ; and R f 0.13 (TLC on silica gel in 25% ethyl acetate in Skellysolve B).
Following the procedures of Examples 36, 38, and 39 but replacing the formula CX oxetane with each of those obtained following Example 35, there are obtained successively the corresponding formula-CXI, -CXII, -CXIII, and -CXIV compounds wherein C p H 2p and its attachment position on the phenyl ring correspond to the specific aldehydes employed following Example 35. These are obtained in both their endo and exo forms.
Further following the procedures of Example 39, but replacing the Wittig ylid reagent with one prepared from a compound of the formula
Br--P(C.sub.6 H.sub.5).sub.3 --CHR.sub.2 --G
wherein --CHR 2 --G is each of the following:
--(CH 2 ) 3 --CH 3
--(ch 2 ) 4 --ch 3
--(ch 2 ) 6 --ch 3
--(ch 2 ) 7 --ch 3
--ch(ch 3 )--(ch 2 ) 5 --ch 3
--ch 2 --ch(ch 3 )--(ch 2 ) 3 --ch 3
--ch 2 --c(ch 3 ) 2 --(ch 2 ) 3 --ch 3
--ch(ch 3 )--c(c 2 h 5 ) 2 --(ch 2 ) 3 --ch 3
--ch 2 --chf--(ch 2 ) 3 --ch 3
--ch 2 --cf 2 --(ch 2 ) 3 --ch 3
--ch(ch 3 )--cf 2 --(ch 2 ) 3 --ch 3 ##SPC140##
--(ch 2 ) 2 --c.tbd.c--c 2 h 5
--ch 2 --ch(ch 3 )--c.tbd.c--c 2 h 5
--ch 2 --c(ch 3 ) 2 --c.tbd.c--c 2 h 5
or
--CH(CH 3 )--CH 2 --C.tbd.C--C 2 H 5
there are obtained the corresponding compounds within the scope of formula CXIV wherein C p H 2p and its attachment to the phenyl ring correspond to the specific compounds of Example 39 and those illustrated in the paragraph immediately thereafter, in both their endo and exo forms.
EXAMPLE 40
2-Exo-{m-[(carboxy)methoxy]}-3-exo-hydroxy-6-endo-(cis-1-heptenyl)bicyclo[3.1.0]hexane (Formula CXVI : C p H 2p is a valence bond with attachment in the meta position, G is n-pentyl, R 1 , R 2 , and R 42 are hydrogen, and ˜ is endo).
Refer to Chart L, step (g). The formula-CXV diol, i.e. 2-exo-(m-hydroxybenzyl)-3-exo-hydroxy-6-endo-(cis-1-hepentyl)bicyclo[3.1.0]hexane (Example 39, 0.19 g.) is treated in 8 ml. of dioxane with bromoacetic acid (0.61 g.) and 6 ml. of 1N. aqueous sodium hydroxide. After the mixture has been heated at reflux for 3 hr., with sodium hydroxide solution added when necessary to maintain a pH of about 10, the mixture is cooled, diluted with 100 ml. of water, and extracted with diethyl ether. The aqueous phase is acidified to pH 1-2 and extracted with ethyl acetate to yield the formula-CXVI title compound, a pale yellow oil, 0.20 g. Recovered formula- CXV diol is obtained from the diethyl ether organic phase on drying and concentrating, 0.025 g.
Following the procedures of Example 40 but replacing bromoacetic acid with a haloacetate within the scope of Hal--CH 2 --COOR 1 as defined herein and specifically illustrated as follows
Cl--CH 2 --COOCH 3
Br--CH 2 --COOC 2 H 5
Cl--CH 2 --COOC 8 H 17 (n)
I--ch 2 --cooch 2 c 6 h 5
cl--CH 2 --COO(m-Cl--C 6 H 4 )
there are obtained the corresponding formula-CXVI compounds wherein R 1 is respectively methyl, ethyl, n-octyl, benzyl, and m-chlorophenyl.
Likewise following the procedures of Example 40 with each of the formula-CXIV compounds disclosed following Example 39 and using each of the haloacetates specifically identified above, there are obtained the corresponding formula-CXVI compounds.
EXAMPLE 41
3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGF 1 .sub.α (Formula CI : C p H 2p is a valence bond with attachment in the meta position, R 30 is n-pentyl, and R 1 and R 2 are hydrogen).
(I.) Refer to Chart L. The formula-CXVI alkene is transformed to the title compound applying the procedures disclosed in U.S. Pat. No. 3,711,515. Thus, compound CXVI (Example 40) is hydroxylated by the procedures of Example 39 of that patent to the formula-CXVII glycol of Chart L, using osmium tetroxide either alone or in combination with N-methylmorpholine oxide-hydrogen peroxide complex.
The glycol is then either (1) sulfonated, for example to yield the bismesylate, and then hydroyzed to a mixture of the title compound and its 15-epimer, applying the procedures of Example 7 of that patent, or (2) treated with substantially 100% formic acid to form the diformate of CI and thereafter hydroyzed to a mixture of the title compound and its 15 epimer, applying the procedures of Examples 20 and 21 of that patent. The epimers are separated by silica gel chromatography to yield the title compound and its 15-epimer.
(II). A third route from glycol CXVII to the title compound is by way of a formula-CXX cyclic ortho ester ##SPC141##
wherein C p H 2p , R 46 , R 47 and ˜ are as defined above. The glycol CXVII is treated as a 1-20% solution in benzene with trimethyl orthoformate (1.5-10 molar equivalents) and a catalytic amount (1% of the weight of the glycol) of pyridine hydrochloride at about 25° C. The reaction is followed by TLC (thin layer chromatography) and is complete in a few minutes. There is thus obtained the formula-CXX cyclic ortho ester in 100% yield.
The cyclic ortho ester is then treated with 20 volumes of 100% formic acid at about 25° C. In about 10 min. the reaction mixture is quenched in water or aqueous alkaline bicarbonate solution and extracted with dichloromethane. The organic phase is shaken with 5% aqueous sodium bicarbonate, dried over sodium sulfate, and concentrated to yield the formula CXXI diester, in this example identical with the diformate of compound CI. The diformate is contacted with 10-50 volumes of anhydrous methanol and 10-20% of its weight of potassium carbonate at about 25° C. until the formyl groups are removed. The mixture of 15-epimers thus obtained is then separated to yield the formula-CI title compound and its 15-epimer.
Following the procedures of Example 41, each of the formula- CXVI alkenes disclosed following Example 40 is converted into the corresponding oxa-phenylene PGF.sub.α analog and its 15-epimer. There are likewise formed the corresponding oxa-phenylene 17,18-didehydro-PGF.sub.α analogs as shown in Chart N.
EXAMPLE 42
2-Exo-[m-(carboxymethoxy)benzyl]-3-exohydroxy-6-endo-(cis-1-heptenyl)bicyclo-[3.1.0]hexane (Formula CXXVII: C p H 2p is a valence bond with attachment in the meta position, G is n-pentyl, R 1 and R 2 are hydrogen, and ˜ is endo).
Refer to Chart M, steps (a)-(f). There is first prepared the formula-CXXII oxetane. Following the procedures of Examples 34 and 35 but replacing the m-acetoxybenzaldehyde of Example 35 with an aldehyde within the scope of ##SPC142##
as to C p H 2p , the attachment position on the phenyl ring, and the carboxyl group R 44 , as defined above, the corresponding formula-CXXII oxetanes are obtained with a fully developed side chain. Specifically, the following formula-CXXXI aldehydes are employed: ##SPC143##
Thereafter, following the procedures of Examples 36, 38, and 39, but replacing the formula-XX ocetane of Example 36 with those obtained by the procedure disclosed in the above paragraph of this example, there are obtained the corresponding formula-CXXVI products. Likewise following those procedures of Examples 36, 38, and 39, but replacing the Wittig ylid reagent of Example 39 with each one disclosed after Example 39, and applying it to each of the above formula-CX compounds of this example, there are obtained the corresponding formula-CXXVI compounds with those specific sidechains.
Finally, the blocking groups on each CXXVI compound are removed by methods disclosed herein or known in the art to yield the formula-CXXVII title compound and the corresponding formula-CXXVII compounds from those formula-CXXVI compounds above.
EXAMPLE 43
2-Exo-{m-[(methoxycarbonyl)methoxy]benzyl{-3-exo hydroxy-6-endo-(cis-1-heptenyl)bicyclo[3.1.0]hexane (Formula-CXXVII: C p H 2p is a valence bond with attachment in the meta position, G is n-pentyl, R 1 is methyl, R 2 is hydrogen, and ˜ is endo).
Refer to Chart M. The formula-CXXVII acid (Example 40, 0.20 g.) is treated in methanol solution at 0° C. with a solution of diazomethane in diethyl ether (prepared from N-methyl-N-nitroso-N'-nitroguanidine (2.0 g.) and potassium hydroxide (6 ml. of 40% aqueous solution)) until a permanent yellow color is produced, and the mixture is concentrated to yield the title compound, a pale tan oil.
EXAMPLE 44
l-6-Endo-(cis-1-heptenyl)-2-exo-{m-[(methoxycarbonyl)methoxy]benzyl}bicyclo[3.1.0]hexan-3-one (Formula CXXVIII: C p H 2p is a valence bond with attachment in the meta position, G is n-pentyl, R 1 is methyl, R 2 is hydrogen, and ˜ is endo).
Refer to Chart M, step (g). The formula-CXXVII methyl ester is oxidized to the bicyclic hexanone as follows. The formula-CXXVII methyl ester (Example 41, 0.21 g.) is added in 2 ml. of dichloromethane to a solution of Collins reagent (prepared from pyridine (0.53 g.) and chromium trioxide (0.34 g.) in 10 ml. of dichloromethane) at about 25° C. for 15 min. The mixture is then shaken with a mixture of 60 ml. of diethyl ether, ice, and 25 ml. of 1 N. aqueous sodium hydroxide, and the organic phase is separated. The organic phase is washed with 1 N. aqueous sodium hydroxide, 1.2 N. aqueous hydrochloric acid, and brine, dried, and concentrated under reduced pressure. The residue, a colorless oil, 0.19 g., is subjected to silica gel chromatography, eluting with 5- 20% ethyl acetate in Skellysolve B. There is thus obtained the formula-CXXVIII title compound, a colorless oil, 0.13 g., having NMR peaks at 0.87, 0.6-3.3, 3.77, 4.60, 4.5-5.1, 5.37-5.95, and 6.58-7.40 δ; [α] D -39° (C=0.8380 in 95% ethanol); and R f 0.42 (TLC on silica gel in 25% ethyl acetate in Skellysolve B).
Following the procedures of Examples 43 and 44, each of the above-identified formula-CXXVII compounds following Example 42 is oxidized to the corresponding formula-CXXVIII compound.
EXAMPLE 45
3-Oxa-3,7-inter-m-phenylene-4,5,6-trinor-PGE 1 , Methyl Ester (Formula XCVII: C p H 2p is a valence bond with attachment in the meta position, R 1 is methyl, R 30 is n-pentyl, and R 2 is hydrogen).
Following the procedures of Example 41, the formula-CXXVIII alkene is transformed in several steps to the title compound.
Likewise, following the same procedures, each of the formula-CXXVIII alkenes disclosed following Example 44 is converted into the corresponding oxa-phenylene PGE analog and its 15 -epimer.
Following the procedures of Examples 34-45, each of the endo intermediates is replaced by the corresponding exo intermediate to yield the corresponding exo intermediate or the ultimate oxa-phenylene PG analog.
Likewise following the procedures of Examples 34-45, each of the optically active isomers is replaced by the corresponding racemic mixture to yield the corresponding racemic intermediate or ultimate oxa-phenylene PG analog. | This invention is a group of PGE 2 -type oxa-phenylene compounds, and processes for making them. These compounds are useful for a variety of pharmacological purposes, including anti-ulcer, inhibition of platelet aggregation, increase of nasal patency, labor inducement at term, and wound healing. | 2 |
BACKGROUND
[0001] The present invention relates to a blower system, and method of controlling a blower system, for use in a powered air purifying respirator (PAPR).
SUMMARY
[0002] When working in areas where there is known to be, or there is a risk of there being, dusts, fumes or gases that are potentially hazardous or harmful to health, it is usual for the worker to use a respirator. A common type of respirator used in such circumstances is a powered air purifying respirator (PAPR). A PAPR has a blower system comprising a fan powered by an electric motor for delivering a forced flow of air to the respirator user. A turbo unit is a housing that typically contains the blower system, and is adapted to connect a filter to the blower system. Air is drawn through the filter by the blower system and passed from the turbo unit through a breathing tube to a headpiece, for example, a helmet or headtop, thus providing filtered air to the user's breathing zone (the area around their nose and mouth). A blower system for a PAPR may also include an electronic control unit to regulate the power driving the fan. Typically, a single power supply, for example a battery, provides power for both the fan and the electronic control unit.
[0003] The electronic control unit can be used, for example, to control the power to the electric motor with the aim of maintaining a substantially uniform volumetric airflow from the blower. The term “volumetric air flow” indicates the volume of air provided to a user at any one time as opposed to the mass of air provided to a user any one time. Sufficient airflow is required by the user to ensure that the designated level of respiratory protection is maintained. However, too high an airflow can cause discomfort and excessive cooling to the user's head inside the headpiece. Too low an airflow can cause ingress of contaminants into the user's breathing zone. The electronic control unit may also be used to trigger alarms to the user, for example, to alert the user if the airflow falls below a designated level, or to alert the user that the filters may be blocked with dust and need to be replaced. It has previously been proposed to control the power to the fan motor of a PAPR blower system in dependence on a combination of motor voltage, motor current and motor speed. Examples of blower control systems of that type are described in US 2008/0127979 and U.S. Pat. No. 7,244,106.
[0004] US 2008/0127979 describes an electronic control system using a pulse width modulation (PWM) ratio as a control variable to generate a specific motor speed and a respective airflow. The PWM ratio is read from a calibration curve stored in the electronic control system.
[0005] U.S. Pat. No. 7,244,106 describes a control unit that detects the power consumption of the motor and the speed of the fan and compares this with a characteristic curve, stored in a memory, for the motor for a given airflow from the fan. In the event of a deviation from this characteristic curve, the control unit regulates a change in the voltage supplied to the motor to maintain a constant airflow.
[0006] A predetermined volumetric airflow of filtered air is usually intended to be delivered to the user of a PAPR to give a certain level of protection from the ingress of particles or gases into their breathing zone. Currently available systems often provide a volumetric airflow that is much higher than is actually needed, rather than risk a situation where too little air is provided. A higher airflow usually means that the battery life between charges is reduced or that larger batteries are required, as more power is consumed to provide the higher airflow. Filter life is also reduced by providing a higher airflow as excess contaminated air is moved through the filters leading to unnecessary filtering and premature clogging or saturation of the filters. As filters are consumable and require replacement many times over the lifetime of the PAPR, this can lead to higher running costs. A further problem is that in many PAPRs a low airflow alarm is required, alerting the user to the fact that the airflow has fallen below a predetermined level. Where an inaccurate airflow measuring or control system is used, the alarm level is often set at an artificially high level to ensure that the user is always safe. This in turn can lead to filters being changed too frequently or the user leaving the workplace unnecessarily. Hence it can be seen that more accurate control of the airflow at a particular volumetric airflow can lead to improved battery lives between charges or the use of smaller and lighter batteries, improved filter life and reduction of premature low airflow alarms. All of these factors can also lead to the improved productivity of the user. It is desirable therefore to use a method of controlling a PAPR that minimizes such issues whilst maintaining or improving the overall functionality of the PAPR.
[0007] The present invention aims to address these problems by providing a method of controlling a powered air purifying respirator blower system to deliver a substantially uniform volumetric airflow to a user, the system comprising a fan powered by an electric motor, controlled by an electronic control unit for delivering a forced flow of filtered air to a user, and the electronic control unit having at least two calibration values for the electrical characteristics of the electric motor stored therein, comprising the steps of: determining one of (a) ambient air density or (b) ambient air temperature and ambient air pressure; and adjusting an electrical characteristic of the electric motor in response to said determination and said at least two calibration values.
[0008] By taking into consideration one or more ambient air characteristics when controlling the blower, the volumetric airflow delivered to the user can be controlled more accurately and hence better functionality of the PAPR can be provided.
[0009] The present invention also provides an air purifying respirator blower system, comprising a fan powered by an electric motor, and an electronic control unit operable to adjust an electrical characteristic of the motor in accordance with a predetermined correlation between the speed of the fan and the applied motor electrical characteristic for a selected substantially uniform volumetric airflow from the fan; wherein the system further comprises at least one sensor adapted to be in communication with the electronic control unit and arranged to determine one of (a) ambient air density or (b) ambient air temperature and ambient air pressure, the electronic control unit being operable in response to the determine (a) ambient air density or (b) ambient air temperature and ambient air pressure, to adjust an electrical characteristic of the motor to maintain the selected substantially uniform volumetric airflow from the fan.
[0010] Other features of the invention will be apparent from the attached dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] By way of example only, embodiments of the invention will now described below with reference to the accompanying drawings, in which:
[0012] FIG. 1 is a diagrammatical illustration of a powered air purifying respirator;
[0013] FIG. 2 shows a block diagram of a blower system according to a first embodiment of the present invention;
[0014] FIG. 3 shows a calibration chart for an electronic control unit of a blower system according to a first embodiment of the present invention;
[0015] FIG. 4 shows the correlation between air density and fan pressure for a second embodiment of the present invention; and
[0016] FIG. 5 shows a block diagram of a blower with a fan pressure measurement sensor for a second embodiment of the present invention.
DETAILED DESCRIPTION
[0017] The present invention is based on the realization that the above-described problems experienced when PAPRs are used at high altitude or below sea level are caused by changes in ambient air density. Ambient air pressure, and hence ambient air density, can vary considerably when working at high altitude or below sea level. Changes in ambient air density can also result from normal fluctuations in ambient air temperature or ambient air pressure. The present invention enables the volumetric air flow delivered to a PAPR user to be controlled more accurately by taking account of the ambient air density and hence provide better functionality of a PAPR. This is done by changing an electrical characteristic, such as the voltage, current or power of the electric motor running the PAPR in accordance with a pre-determined calibration procedure.
[0018] The term “ambient” is used herein to describe the air density, temperature, pressure or humidity experienced by the user. Ambient air density is affected, for example, by ambient air pressure, ambient air temperature and ambient air humidity. The degree to which each of these factors effect the ambient air density is different, with air pressure usually having the greatest effect. Although air temperature and humidity are believed to have a lesser effect, these factors may still be taken into account when determining ambient air density and volumetric airflow.
[0019] The term “humidity” can be taken to mean any of absolute humidity, specific humidity or relative humidity. Absolute humidity is defined as being the quantity of water in a particular volume of air. Specific humidity is defined as being the ratio of water vapour to air. Relative humidity is defined as being the ratio of the partial pressure of water vapour in a gaseous mixture of air and water vapour to the saturated vapour pressure of water at a given temperature. Measurement of any of the absolute, specific or relative humidity value may be carried out as appropriate, depending on user preference and ambient conditions.
[0020] By way of example only, the effects of ambient air pressure, temperature and humidity over the ranges that a PAPR could foreseeably be used include:
[0021] Ambient Pressure—changing the atmospheric pressure from 1100 mbar e.g. at sea level, to 750 mbar e.g. 2500 metres above sea level, would see a reduction in air density to approximately 68% of the initial air density;
[0022] Ambient Temperature—changing the air temperature from 0° C. up to 50° C. would see a reduction in air density to approximately 84% of the initial air density.
[0023] Ambient Humidity—changing the ambient humidity, relative humidity RH, from 0% RH to 100% RH, at 0° C. would see a reduction in air density to approximately 99.7% of the initial air density, at 25° C. would see a reduction in air density to approximately 98.8% of the initial air density, and at 50° C. would see a reduction in air density to approximately 96.5% of the initial air density.
[0024] Therefore, applying air density compensation based on only ambient air pressure can compensate for considerable variation and inaccuracies. Compensation based on both pressure and temperature improves accuracy further still. Compensation based on humidity, temperature and pressure gives the best possible accuracy, but only marginally better than temperature and pressure.
[0025] Each of the embodiments described below employ a turbo as shown in FIG. 1 . FIG. 1 is a diagrammatical illustration of a powered air purifying respirator. The PAPR comprises a headpiece 1 , a turbo unit 2 , a breathing tube 3 , a filter 4 and a belt 5 . The headpiece 1 is worn on the user's 6 head. It at least partially encloses the user's 6 head to form a breathing zone 7 , that is, the area around their nose and mouth, so that the filtered air is directed to this breathing zone 7 . The turbo unit 2 may be attached to a belt 5 to enable it to be secured about the user's torso. The turbo unit 2 houses a blower system (not shown), which draws the air through the PAPR system using a fan (also not shown). The turbo unit 2 supplies air to the headpiece 1 through the breathing tube 3 which is connected between the outlet 8 of the turbo unit 2 and the inlet 9 of the headpiece 1 . The turbo unit 2 is fitted with a filter 4 , which can be either inside the turbo unit or attached to the turbo unit as shown in FIG. 1 such that the filter 4 is in the airflow path, preferably disposed upstream of a fan opening of the blower. The purpose of providing the filter 4 is to remove particles and/or gases and/or vapours from the ambient air before the air is delivered to the user 6 . The battery pack 10 , which is fitted to the turbo unit 2 provides power to the electronic control unit 23 and to the motor 22 (both shown in FIG. 2 as discussed below).
[0026] The following illustrates how the blower system in accordance with a first embodiment of the present invention may operate. In the following examples, the structural components of the PAPR may be assumed to be as described above with reference to FIGS. 1 and 2 .
[0027] FIG. 2 shows a block diagram of a blower system according to a first embodiment of the present invention. This blower system is housed within the turbo unit 2 illustrated in FIG. 1 . In accordance with this embodiment of the invention the blower 20 includes a housing 17 having an inlet 18 and an outlet 19 . The blower 20 further includes a fan 21 , having a plurality of blades 16 , driven by a motor 22 . The blower 20 is controlled by an electronic control unit 23 which regulates the power provided to the motor 22 .
[0028] It is desirable that a predetermined, substantially uniform volumetric airflow be supplied to the user's breathing zone 7 , such that when the user 6 inhales, sufficient filtered air is available for the user 6 to breathe easily and normally, and no potentially contaminated ambient air is inhaled. A substantially uniform volumetric airflow is preferably, but not limited to, an airflow rate where the deviation from the desired or predetermined airflow is in the range −5 to +15 litres per minute.
[0029] In order to achieve a substantially uniform volumetric airflow at a particular volumetric airflow rate, either the airflow must be known or a correlation between various operating parameters and the required airflow must be known. It is possible to monitor the volumetric airflow by using a discrete airflow sensor. However, in the present invention, it has been appreciated that various operating parameters of the fan 21 and motor 22 including fan or motor speed, motor voltage, motor current and motor power can be used to determine the volumetric airflow as described below.
[0030] With further reference to FIG. 2 , the blower system comprises an electronic control unit 23 that functions to maintain a substantially uniform, preferably constant, volumetric airflow to the headpiece 1 . The electronic control unit 23 comprises: a microprocessor device 24 , such as a single chip microcontroller, for computing information; a memory device 25 , such as flash RAM, for storing information, for example, calibration data; sensor input receivers 26 a , 26 b , 26 c , for receiving data from sensors such as motor current sensors and fan speed sensors; and an output controller 27 , such as a pulse width modulation controller chip, for providing power to the motor 22 and any alarm or status indicators, such as buzzers or light emitting diodes, that may be included in the PAPR. The memory device 25 of the electronic control unit 23 has two parts: a fixed memory and a temporary memory. The fixed memory is populated with data, for example, at the time of manufacture, comprising the algorithms and programs for enabling the microprocessor 24 to carry out its calculations and procedures, and calibration information from the factory calibration procedure. The temporary memory is used for storing data and information such as sensor readings and fan operating parameter data collected during start-up and running of the turbo unit 2 . If desired, this data maybe erased when the turbo unit 2 is powered down.
[0031] A three-phase square-wave, brushless, direct current motor 22 may be used to drive the fan 21 of the blower 20 . The equations below, EQ.1, EQ.2 and EQ.3 are well known and show the relationships between the main parameters of such a motor.
[0000]
T
=
k
T
I
(
Eq
.
1
)
E
=
k
E
2
π
60
n
(
Eq
.
2
)
V
s
=
E
+
R
m
I
T
Air
gap
torque
(
mNm
)
k
T
Torque
constant
(
mNm
/
A
)
I
Motor
current
(
A
)
E
Back
EMF
(
V
)
k
E
Back
EMF
constant
(
Vs
/
rad
)
n
Speed
(
rpm
)
V
s
Applied
motor
voltage
(
V
)
R
m
Winding
resistance
(
Ω
)
(
Eq
.
3
)
[0032] As explained above, the blower 20 comprises a fan 21 which is used to move air through the filter(s) 4 and deliver it to the user 6 . The fan 21 illustrated in the drawings is of the type often known as a centrifugal or radial fan, meaning that the air enters the fan in the direction of the fan axis and exits in a radial direction to the fan.
[0033] The fan law equations below show how the performance of the fan 21 changes when the fan speed and the air density are changed.
[0000]
Q
V
2
=
Q
V
1
n
2
n
1
(
Eq
.
4
)
p
2
=
p
1
(
n
2
n
1
)
2
ρ
2
ρ
1
(
Eq
.
5
)
T
2
=
T
1
(
n
2
n
1
)
2
ρ
2
ρ
1
(
Eq
.
6
)
P
2
=
P
1
(
n
2
n
1
)
3
ρ
2
ρ
1
Q
v
:
Volumetric
air
flow
(
1
/
min
)
p
:
Fan
pressure
(
Pa
)
T
:
Torque
(
mNm
)
P
:
Input
shaft
power
(
W
)
n
:
Fan
speed
(
rpm
)
ρ
:
Air
density
(
kg
/
m
3
)
(
Eq
.
7
)
[0034] It can be seen from equation EQ. 4 that in order to maintain a substantially uniform volumetric airflow, the fan speed element of the calibration point must remain unchanged.
[0000] n 2 =n 1 (8)
[0035] Furthermore, combining equations EQ.1, EQ.2, EQ.3 and EQ.6 shows how to move the applied motor voltage element of the calibration point when the air density changes.
[0000]
V
S
2
=
V
S
1
+
ρ
2
-
ρ
1
ρ
1
I
1
R
m
(
Eq
.
9
)
V
S
2
=
V
S
1
+
ρ
2
-
ρ
1
ρ
1
(
V
S
1
-
k
E
2
π
60
n
1
)
n
1
,
V
S
1
:
Calibration
point
as
air
density
ρ
1
n
2
,
V
S
2
:
Calibration
point
at
air
density
ρ
2
I
i
:
Motor
current
(
A
)
at
air
density
ρ
3
R
m
:
Motor
winding
resistance
(
Ω
)
V
s
:
Applied
motor
voltage
(
V
)
n
:
Fan
speed
(
rpm
)
ρ
:
Air
density
(
kg
/
m
3
)
k
E
:
Back
EMF
constant
(
Vs
/
rad
)
(
Eq
.
10
)
[0036] In conclusion, it can be seen that in order to compensate for changes in ambient air density, the fan speed element of the calibration point does not need to be changed (see equation EQ.8). However, the applied motor voltage element of the calibration point does need to be changed when the ambient air density changes, according to equations EQ.9 and EQ.10.
[0037] FIG. 3 shows a calibration chart for an electronic control unit of a blower system according to a first embodiment of the present invention. This is used during the procedure for determining a substantially uniform volumetric airflow. The electronic control unit 23 refers to the calibration chart 30 , which indicates a directly proportional relationship between fan speed and applied motor voltage. A predetermined substantially uniform volumetric airflow is represented by two calibration points, high 31 and low 32 . Each calibration point comprises information about applied motor voltage and fan speed. To maintain a substantially uniform volumetric airflow, for example, as the filter(s) 4 progressively clog with dust and fumes and hence the performance of the blower 20 changes, the electronic control unit 23 tracks along the line 33 between the two calibration points 31 , 32 . This may be done using a look up table or other data array. The electronic control unit takes a measurement of the fan speed using a sensor 28 , compares it with the calibration line and then applies the appropriate motor voltage 29 to maintain the pre-determined volumetric airflow.
[0038] In the present invention, the realization that the calibration points, and hence the tracking line, are optimal for one specific air density, is utilised. By taking measurements of air density, the calibration points can be moved appropriately to account for the actual air density and maintain a substantially uniform volumetric airflow.
[0039] The fan speed is measured by means of a sensor 28 fitted to the blower 20 that measures the number of revolutions of the fan 21 in a given time. A suitable type of sensor for measuring the fan speed would be a Hall effect device, although other types of sensor could be used. The fan speed information is received by the microprocessor device 24 of the electronic control unit 23 . The applied voltage 27 to the electric motor 22 is monitored directly by an input 26 to the microprocessor 24 of the electronic control unit 23 .
[0040] Sensors for measuring the ambient temperature and ambient pressure may be used to determine the ambient air density. A suitable low cost sensor for measuring both the ambient pressure and temperature is a solid state type sensor from the SCP1000 series of sensors manufactured by VTI Technologies Oy, FI-01621, Vantaa, Finland. Such temperature and pressure sensors are cheaper, more widely available, more reliable and easy to position than discrete airflow sensors. Alternatively, separate temperature and pressure sensors could also be used, if desired; most solid state temperature and pressure sensors capable of measuring atmospheric temperature or pressure would be suitable.
[0041] The temperature and pressure sensor 29 is preferably located in the turbo unit 2 . It is important that the housing is not sealed so that the sensor is open to the atmosphere. The location of the sensor 29 should be chosen such that it is not significantly affected by any other parts of the blower 20 or electronic control unit 23 . This is to avoid fluctuations in temperature during use caused by the operation of other blower components as this may give false ambient temperature measurements. The sensor 29 should not be located in an area of the turbo unit 2 that is pressurised or depressurised during use, as this would also give rise to erroneous measurements.
[0042] The following steps are carried out when the turbo unit 2 is initially calibrated during manufacture. High 31 and low 32 calibration points for each predetermined substantially uniform volumetric airflow are determined. Fan speed and applied motor voltage 32 for each calibration point are also measured and saved in the electronic control unit's fixed memory 25 . At least one of the ambient pressure and temperature at calibration is measured by the sensor(s) 29 via the electronic control unit 23 and saved in the fixed memory 25 . The air density is calculated by the microprocessor 24 using an appropriate algorithm and saved in the fixed memory as the nominal air density. Alternatively the air density is measured directly, and the same calibration process carried out.
[0043] The calibration points will have to be moved as air density changes by the air density compensation procedure described below. When ambient air pressure and temperature have been measured as part of the calibration process, the following steps are used. At start-up of the turbo unit, that is, when the turbo unit is switched on, the sensors 29 may measure both the actual ambient pressure and temperature, which is likely to be different to that measured at the point of factory calibration. The actual air density is then calculated from these values by the microprocessor 24 and saved in the temporary memory. The nominal applied motor voltage component of all the calibration points 31 , 32 stored in the fixed memory is read out by the microprocessor 24 . Each component is then modified using the expression of equation EQ.10, and the air density information previously saved in the fixed memory at the time of factory calibration and the actual air density information saved in the temporary memory. The modified values are and saved in temporary memory as corrected calibration points. As with the calibration procedure, an upper 35 and a lower 36 corrected calibration points are saved.
[0044] The nominal fan speed part of the calibration points 31 , 32 is not changed. The new corrected calibration points can now be used in the substantially uniform volumetric airflow maintenance procedure. For example, as the filter(s) 4 progressively clog, for example, with dust and/or fumes, and the performance of the blower 20 changes, the electronic control unit 23 tracks along a line 34 between the two corrected calibration points 35 , 36 . The air density compensation procedure is repeated at regular intervals, for example every ten minutes or every hour, and airflow adjusted accordingly if necessary.
[0045] Thus the above procedure can enable the turbo unit 2 to deliver substantially uniform volumetric airflow rates which are compensated for air density fluctuations.
[0046] The benefit of more accurate control of the substantially uniform volumetric airflow is that the airflow does not need to be set artificially high to take account of changes or fluctuations in air density. In contrast, the substantially uniform volumetric airflow can be set at a level where the required respiratory protection is exceeded but the life of the batteries 10 between charges and the life expectancy of the filter(s) 4 is maximised. Thus the running costs of the PAPR may be reduced, and the amount of downtime for the user 6 should also be reduced, as battery 10 life between charges is longer and filter(s) 4 require changing less frequently.
[0047] Typically, air should be delivered to the user 6 at a predetermined substantially uniform volumetric airflow. In certain circumstances, however, the user 6 may need to be able to adjust the airflow to a different level. For example if the user 6 is working particularly hard and breathing more deeply or at a faster rate than usual, they may desire to increase the airflow. To enable this, the electronic control unit is preferably provided with a discrete range of two, three or more different, pre-set airflow values, for example, 160 litres per minute or 180 litres per minute. However, the control unit is usually set such that it is not possible for the user 6 to inadvertently reduce the airflow below a level where the minimum protection is given.
[0048] A further embodiment of the present invention using an alternative air density compensation procedure will now be described.
[0049] FIG. 4 shows the correlation between air density and fan pressure for a second embodiment of the present invention. For a radial fan used in PAPR blower system, there is a correlation 40 between the air density and the fan pressure, at a predetermined fan speed and a predetermined motor voltage. FIG. 5 shows a block diagram of a blower with a fan pressure measurement sensor for an embodiment of the present invention. The fan pressure is a measurement of the differential pressure between the inlet 51 of the fan and the outlet 52 of the fan as shown in FIG. 5 . Hence the fan pressure can be measured by means of a differential pressure transducer 53 fitted to the blower. The air density calculation can be performed at start-up of the PAPR by running the blower system for a short period of time at the predetermined fan speed and motor voltage conditions, during which, the fan pressure can be measured and the ambient air density determined. The correlation information can be stored in the memory of the electronic control unit and the calculation of air density conducted by program in the microprocessor.
[0050] A third embodiment in accordance with the present invention uses an alternative method of determining air density compensation. The user 6 is required to create a certain condition to enable the air density measurement to be achieved. At the point of factory calibration during manufacture of the PAPR, a known load condition is created. A known load condition is a previously measured pressure loading on the blower that is not affected by unknown pressure influences such as partial clogging of the filter. The known load condition could be either a minimum load, which is when no filters or breathing tube 3 are connected to the turbo unit 2 , or a maximum load which is when the outlet 8 of the turbo unit 2 is blocked. Under whichever one of these conditions that is chosen, the motor voltage is fixed and the fan speed is measured and both values, together with the ambient air density at the time of calibration are stored in the electronic control unit memory. During use, the user 6 is required to create the same load condition and start a calibration sequence. The electronic control unit would then start the blower 20 running at the same motor voltage as the factory calibration. The fan speed is then measured and compared to the fan speed during calibration and together with the air density at calibration, used to determine the current air density. The user 6 can then set up the PAPR for use and the air density compensation procedure can be applied.
[0051] The method in accordance with the third embodiment can use any two of the parameters motor voltage, motor current or fan speed, by holding one parameter constant and measuring the other, in combination with either the maximum or minimum load condition.
[0052] The air density also may be determined by various means, alternative to those described previously. In accordance with a fourth embodiment of the present invention, the air density can be measured or calculated independently of the PAPR. This may be, for example, by a separate, dedicated air density measuring instrument. A PAPR can be enabled to allow the user 6 to input the air density via a man-machine-interface such as a keypad or a touch screen. In this embodiment, the electronic control unit would not need to perform any air density calculations when applying the air density compensation procedure.
[0053] A PAPR in accordance with this embodiment of the present invention can also be enabled to allow the atmospheric pressure, ambient temperature, or ambient humidity, or preferably a combination of these parameters to be inputted into the electronic control unit via a suitable interface. The electronic control unit can be enabled to calculate the ambient air density prior to performing the air density compensation procedure. This method would require the user 6 to measure the parameters independently from the PAPR using suitable measuring instruments.
[0054] Air density compensation may be achieved by the user 6 inputting the altitude into the electronic control unit. The altitude can be obtained by the user 6 taking a measurement with a suitable instrument, or by reference to a map or GPS system. The electronic control unit can be enabled to estimate the ambient pressure and hence an approximation of air density at the given altitude by using pre-programmed information stored in its memory.
[0055] Although in the above-described examples and embodiments of the present invention the electrical characteristic of the electric motor 22 used to control the volumetric airflow is voltage, t is easily envisaged that the current or power output of the electric motor 22 could be used as an alternative, in both the calibration process and during use.
[0056] The headpiece 1 may have a variety of configurations. Although a hood is illustrated in FIG. 1 , the headpiece 1 could be a helmet, a mask, or a full suit, provided it covers at least the orinasal area of the user's face, to direct air to the user's breathing zone 7 . Full face respirators or half face mask respirators may be used as headpieces in conjunction with the embodiment of the present invention. Alternative ways of supporting the turbo unit 2 on a user's body 6 or otherwise are also within the scope of the present disclosure. For example, a backpack-type support may be provided for the turbo unit 2 .
[0057] Generally when using a helmet or hood in a PAPR, a higher constant airflow is desired, than when a mask is used. Where the user 6 may change between helmets and masks, or where the turbo unit 2 is shared between multiple users, it is desirable to have a range of substantially uniform volumetric airflows. The range of substantially uniform volumetric airflows may be continuously variable between a first airflow rate and a second airflow rate, or may be a series of discrete steps between the first and second airflow rates. For example, a system may be set to a first predetermined airflow value for use with a PAPR and to a second, lower, predetermined airflow value for use with a mask.
[0058] A PAPR with air density compensation as described above may also be designed with smaller and lighter batteries, and smaller and lighter or lower profile filters. The turbo unit 2 may be fitted with more than one filter 4 in the airflow path, to remove particles and/or gases and vapours from the ambient air before the air is delivered to the user 6 . The filter or filters 4 may be inside the turbo unit 2 or fitted to the outside of the turbo unit 2 . The battery 10 , may be attached to the turbo unit 2 as illustrated in FIG. 1 or may be remote from the turbo unit 2 and connected by a suitable cable.
[0059] The motor used in the embodiments described above is a three-phase square-wave brushless direct-current motor. Alternatively, a segmented commutator brushed direct current motor may be used. As the equations EQ.1, EQ.2 and EQ.3 are known to be true for both the brushed and brushless types of motors. Consequently, most types of direct current motors known within the respirator industry could be used in the blower 20 of the present invention. Other non-direct current types of motors that are know in the art for PAPR applications could be used as an alternative to that in the embodiment described above. Alternative motor control methods, such as pulse width modulation are also envisaged as being within the scope of the present invention. | A method of controlling a powered air purifying respirator blower system to deliver a substantially uniform volumetric airflow to a user ( 6 ) includes the steps of determining one of (a) ambient air density or (b) ambient air temperature and ambient air pressure, and adjusting an electrical characteristic of the electric motor ( 22 ) in response to said determination and said at least two calibration values. The powered air purifying respirator blower system may include a fan ( 21 ) powered by an electric motor ( 22 ), the motor being controlled by an electronic control unit ( 23 ) for delivering a forced flow of filtered air to a user ( 06 ). The electronic control unit ( 23 ) may include at least two calibration values for the electrical characteristics of the electric motor ( 22 ) stored therein. The system may include at least one sensor ( 26 ) adapted to be in communication with the electronic control unit and arranged to determine one of (a) ambient air density or (b) ambient air temperature and ambient air pressure. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of and claims the benefit of U.S. patent application Ser. No. 10/405,169 having a filing date of Apr. 2, 2003 now U.S. Pat. No. 7,476,347, which is continuation-in-part of U.S. patent application Ser. No. 10/106,741 filed Mar. 26, 2002, now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 09/682,440 filed Sep. 4, 2001, now U.S. Pat. No. 6,592,369, which is a continuation-in-part of U.S. patent application Ser. No. 09/670,364 filed Sep. 26, 2000, now abandoned, the entire contents of which are hereby incorporated by reference. The application further claims the benefit of U.S. Provisional Patent Application Ser. No. 60/237,523 filed Oct. 4, 2000; U.S. Provisional Patent Application Ser. No. 60/201,705 filed May 3, 2000, and U.S. Provisional Patent Application Ser. No. 60/164,893 filed Nov. 10, 1999.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a continuous tooth making system in accordance with the invention;
FIG. 2 is a cross-sectional side view of an integral tooth and denture base in accordance with the invention;
FIG. 3 is a schematic representation of an information collection, denture forming and information transmission system in accordance with the invention;
FIG. 4 is a top view a schematic representation of device making system in accordance with the invention;
FIG. 5 is a side view a schematic representation of the device making system shown in FIG. 4 ;
FIG. 6 is a cross-sectional end view schematic representation of a denture made in the device making system shown in FIGS. 4 and 5 ; and
FIG. 7 is a schematic representation of a spray head forming a device in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides integrally connected dental devices. The invention is now described with more particular reference to FIGS. 1 through 7 . With more particular reference to FIG. 1 is seen a schematic view of a continuous tooth making system 10 having source of polymerizable material 12 feeding a strip of polymerizable material 14 between rotating molds 16 and 18 to form artificial teeth 20 , 24 , 26 , 28 , 30 , 32 , 34 , 36 and 38 . The artificial teeth drop onto and are carried by moving belt 22 .
With more particular reference to FIG. 2 is seen an integral tooth and denture base 100 having an artificial tooth portion 112 integrally formed with denture base portion 114 .
In a preferred embodiment of the invention a polymerizable material 12 made be placed in polymerizable denture base material and light cured to form integral tooth and denture base 100 . During polymerization of the polymerizable dental material it is believed that the dental material flows between the artificial tooth and the denture base while polymerizing. Preferably a cross-linked system is formed. After polymerization of the polymerizable dental materials, there is no detectable interface in the region of the integral connection of the artificial tooth to the denture base. In a preferred embodiment of the temperature of the denture base is below temperatures at which the material of the artificial tooth is flowable. Initially there is a detectable interface between the artificial tooth material to the denture base material.
Integral connections, as used herein, refers to adjacent regions of a polymerized product that are flowable while they are polymerized. For example, when heated adjacent regions of a polymerizable artificial tooth (containing monomer and oligomer) and a polymerizable denture base (containing monomer and oligomer) become flowable, and flow while they polymerize. Thus, in the initial stage of polymerization, monomer and oligomer flow from the polymerizable artificial tooth into the adjacent polymerizable denture base. Similarly, monomer and oligomer flow from the polymerizable denture base into the adjacent polymerizable artificial tooth.
The invention provides a dental device, having an artificial tooth and a denture base. The artificial tooth is integrally connected to the denture base. In a preferred embodiment of the invention the artificial tooth is preferably shaped by a continuous molding method. Alternatively the artificial tooth is transfer molded or injection molded. The dental device is formed from polymerizable dental material, which may include one or more initiating systems to cause them to harden promptly.
Thus, as described above in discussing FIG. 2 , for a preformed artificial tooth placed into a denture base, if the temperature of the denture base is below temperatures at which the material of the artificial tooth is flowable, then initially there will be a detectable interface between the artificial tooth to the denture base. During polymerization of the polymerizable dental material it is believed that the dental materials flow between the artificial tooth and the denture base. After polymerization of the polymerizable dental material, there is no detectable interface in the region of the integral connection of the artificial tooth to the denture base.
However, if the temperature of the denture base is at or above temperatures at which the material of the artificial tooth is flowable, then initially there will not be a detectable interface between the artificial tooth to the denture base. During polymerization of the polymerizable dental material it is believed that the dental materials flow between the original artificial tooth and the original denture base. After polymerization of the polymerizable dental material, there is no detectable interface in the region of the integral connection of the artificial tooth to the denture base. In the dental device the artificial tooth is integrally connected to the denture base. The dental device is preferably formed from an artificial tooth having tooth material and a submerged tooth surface. A portion of the tooth material flows through the submerged surface into the adjacent denture base. The adjacent denture base includes denture base material. A portion of the denture base material flows through the submerged surface of the artificial tooth whereby the submerged surface of the tooth is assimilated into the tooth material and the adjacent denture base material to form an integral connection between the artificial tooth and the denture base. The flow of tooth and denture base materials typically occurs during polymerization. When polymerization is complete cross-sections of an artificial tooth integrally connected to a denture base at the position of the pre-flowing tooth surface and the adjacent pre-flowing denture base are without a detectable residue of the pre-flowing tooth surface contacting the denture base material. When polymerization is complete cross-sections of an artificial tooth integrally connected to a denture base at the position of the pre-flowing tooth surface and the adjacent pre-flowing denture base have flexural strength and flexural modulus which are each effectively an average of the flexural strength and flexural modulus of the adjacent materials.
Light curable polymerizable dental materials preferably include a light sensitizer, for example camphorquinone, Lucirin TPO, or methyl benzoin which causes polymerization to be initiated upon exposure to activating wavelengths of light; and/or a reducing compound, for example tertiary amine. A room temperature or heat activating catalyst system is preferably included in the polymerizable dental material. For example a peroxide capable of producing free radicals when activated by a reducing agent at room temperature or by heating. Preferred peroxides include benzyl peroxide and lauroyl peroxide.
Compositions useful in accordance with the invention may further include fillers, pigments, stabilizers, plasticizers and fibers. Preferably, these polymerizable dental compositions include from about 2 to about 95 percent by weight filler particles. More preferably, these compositions include from about 10 to about 85 percent by weight filler. Nanocomposites and ceramers may be formed from these composites. The fillers preferably include both organic and inorganic particulate fillers to further reduce polymerization shrinkage, improve wear resistance and modify the mechanical and physical properties.
A preferred embodiment of the invention uses a high strength dental polymeric material formed by light curing polymerizable dental material shaped into at least a portion of a denture base or tooth. Preferably the polymerizable dental material has a flexural modulus of at least 250,000 psi and a flexural strength of at least 7,000 psi. Preferably a denture of the invention comprises a denture base and a tooth integrally connected and comprising an interpenetrating polymer network polymeric matrix and at least 0.1 percent by weight of self-lubricating particles having a particle size less than 500 microns effectively bonded to and distributed in the polymeric matrix. Preferably the integral connection of the denture base and a tooth is effectively greater than a bond strength of 4,480 psi.
“Wax-like material” as used herein refers to material which is flowable (fluid) above 40° C. and becomes dimensionally stable (solidifies: i.e. is nonfluid) at least at and below 23° C., within 5 minutes. Thus, wax-like material is flowable when it is at and above 40° C., and becomes dimensionally stable when it is at and below 23° C. Flowable wax-like material having a temperature from 100° C. to 40° C., becomes dimensionally stable within 5 minutes by cooling by exposure to an ambient temperature between 23° C. and 0° C. Flowable wax-like material having a temperature from 100° C. to 40.° C., becomes dimensionally stable within (in order of increasing preference) 2, 1, 0.5 or 0.3 minutes by cooling by exposure to an ambient temperature between 23° C. and 0° C.
“Wax-like spray material” as used herein refers to material which is fluid at temperatures of fluidity of the wax-like spray material, and dimensionally stable (solidifies: i.e. is nonfluid) at temperatures of dimensional stability of the wax-like spray material, which is adapted to be spayed as a fluid, and adapted to solidify from a fluid spray to being dimensionally stable within 5 minutes of the fluid spray contacting a substrate which is at temperatures of dimensionally stability of the wax-like spray material. Preferably, wax-like spray material (in order of increasing preference) is flowable (fluid) within the range of 1° C. to 100° C.; 2° C. to 80° C.; 4° C. to 60° C.; or 5° C. to 50° C. above the highest temperature of the temperatures of dimensionally stability of the wax-like spray material. Preferably, wax-like spray material becomes dimensionally stable within (in order of increasing preference) 2, 1, 0.5, 0.3 or 0.1 minute(s) by cooling by contacting a substrate at temperatures of dimensionally stability of the wax-like spray material. Preferably, a dental product is formed from wax-like spray material within an enclosure at an average ambient temperature within the enclosure between 0° C. and 80° C. More preferably, the average ambient temperature within the enclosure is between 15° C. and 50° C. Most preferably, the average ambient temperature within the enclosure is between 20° C. and 40° C.
“High strength dental polymeric material” as used herein refers to material having a polymeric matrix having a flexural modulus of at least 250,000 psi and a flexural strength of at least 5,000 psi. Optionally, high strength dental polymeric material includes reinforcing filler. However, the polymeric matrix alone (without any reinforcing filler) has a flexural modulus of at least 250,000 psi and a flexural strength of at least 5,000 psi. Preferably high strength dental polymeric material has a polymeric matrix having a flexural modulus of at least 300,000 psi and a flexural strength of at least 7,000 psi. More preferably high strength dental polymeric material in order of increasing preference has a polymeric matrix having a flexural modulus of at least 350,000 psi and a flexural strength of at least 12,000 psi. Artificial teeth and denture base both made of high strength dental polymeric material are integrally connected in dental products including full dentures, partial dentures and bridges during polymerization of polymerizable dental material.
“Flexural strength, and flexural modulus” as used herein refers to results of testing according to ASTM D790 (1997). “Notched impact strength” as used herein is also referred to as “notched Izod impact resistance” and refers to results of testing according to ASTM D256 (1997). “Un-notched impact strength” as used herein refers to results of testing according to ASTM D4812 (1993).
Integral dental devices in accordance with a preferred embodiment of the invention have at least one artificial tooth integrally connected to the denture base, and are formed of high strength dental polymeric material. The integral connection of each artificial tooth to the denture base provides superior strength in joining artificial teeth to denture base compared to prior art dental devices. The integral connection of each artificial tooth to the denture base eliminates the need for a coating of a bonding agent there between in prior art dental devices. The integral connection of each artificial tooth to the denture base provides superior sealing at the margins (outer surfaces) in joining artificial teeth to denture base compared to prior art dental devices.
With more particular reference to FIG. 3 is seen system 200 having information collection 212 and dental product forming 214 with information transmission 216 from information collection 212 to dental product forming 214 . Information collection 212 provides three-dimensional digital information representative of a portion of a patient's mouth. Information collection 212 may for example be the apparatus for producing a three-dimensional digital model disclosed by Sachdeva in U.S. Pat. No. 6,512,994, incorporated herein by reference in its entirety. Alternatively, Information collection 212 may be the impression tray scanning apparatus disclosed by Hultgren in U.S. Pat. No. 6,2000,135, incorporated herein by reference in its entirety.
Digital information or data representative of a tooth enamel and shader outer surfaces are prepared, for example as disclosed in U.S. Pat. No. 6,174,168 (incorporated herein by reference in its entirety) or retrieved from memory of a computer loaded with CAD/CAM software program. This data and three-dimensional digital information from information collection 212 representative of a portion of a patient's mouth, which may both be in the form of the numerical coordinates of a spray path program, are collected by a memory device and may be down loaded or transferred to a floppy disk. The spray path program may be used to display and edit features of the dental product to be formed. The edited spray path program may be stored on a floppy disk and down loaded into the memory (such as a digital storage unit) of control system 330 of dental product making system 300 . The spray path program is used to direct and control the machine in the fabrication of the dental product. The spray path program forms the lower surface of the dental product using the three-dimensional digital information from information collection 212 representative of a portion of a patient's mouth. The spray path program forms the upper outer surface of the dental product using the digital information representative of tooth enamel outer surfaces.
Information transmission 216 may be in digital form, and carried for example on diskette or transferred via a telephone system, such as the internet. Dental product forming 214 may, for example, be by liquid jet deposition of pigmented photopolymerizable (light curable) material. Information collection 212 may, for example, be by scanning a patient's mouth or scanning a mold (or an impression) of a patient's mouth. Preferably, information collection 212 provides information about a patient's mouth in machine readable form.
In accordance with a preferred embodiment of the invention is provided a denture made by a process comprising: collecting digital information regarding a mouth, and forming a denture using the information. Preferably the forming of the denture comprises computer aided manufacture. The collecting digital information regarding a mouth is preferably by scanning at least a portion of the mouth or by taking an impression of at least a portion of the mouth and scanning the impression. The denture is formed using the information at the same or at a location remote to the collecting of digital information regarding a mouth. Thus, the invention provides a denture made by a process comprising: collecting digital information regarding a mouth at a first location, and forming a denture using the information at a second location. Preferably the process further comprises transferring the digital information from the first location to the second location through a telephone system. Preferably the process further comprises storing the digital information on a disk and transferring the disk from the first location to the second location.
With more particular reference to FIGS. 4 and 5 is seen dental product making system 300 having jet and curing system 312 above support surface 314 . A denture layer 316 C is formed by spraying and curing the polymerizable material from jet and curing system 312 onto support surface 314 . Jet and curing system 312 is incrementally moved in a plane above support surface 314 by horizontal actuators 320 and 321 . For each increment jet and curing system 312 is moved in a plane above support surface 314 jet and curing system 312 is moved laterally across at least a portion of support surface 314 by lateral actuators 318 and 319 .
Vertical actuator 324 is connected by actuator 326 to frame 328 . Frame 328 is connected to support surface 314 and horizontal actuators 320 and 321 . After jet and curing system 312 is incrementally moved through at least a portion of a plane above support surface 314 by horizontal actuators 320 and 321 , vertical actuator 324 lowers support surface 314 and horizontal actuators 320 and 321 a distance corresponding to the height of the added layer of polymerizable material sprayed and polymerized.
Control system 330 received information from input and communication system 332 . Control system 330 is connected to horizontal actuators 320 and 321 , lateral actuators 318 and 319 and vertical actuator 324 through horizontal actuator electrical conductors 320 C and 321 C, lateral actuator electrical conductors 318 C and 319 C and vertical actuator electrical conductor 324 C, respectively. Control system 330 controls actuator movement of horizontal actuators 320 and 321 , lateral actuators 318 and 319 and vertical actuator 324 .
Control system 330 is connected to light sources 340 and 342 through light sources electrical conductors 340 C and 342 C. Control system 330 controls the emission of curing light from light sources 340 and 342 .
Control system 330 is connected through control valve electrical conductor 346 C to control valve for reservoir 346 . Control system 330 controls the flow of fluid from reservoir 346 by opening and closing of a valve reservoir 346 . Fluid flowing from reservoir 346 sprays onto denture layer 316 C. Denture forming fluid from reservoir 346 is light curable polymerizable material. With more particular reference to FIG. 6 is seen denture 316 having a denture base and artificial teeth formed on surface 314 in integrally connected layers 316 A, 316 B and 316 C.
With more particular reference to FIG. 7 is seen a spray and curing head system 400 having spray and curing head 412 . Spray and curing head 412 may be used in place of jet and curing system 312 in dental product making system 300 . Transparent support 414 may be used in place support surface 314 , in dental product making system 300 .
As spray and curing head 412 is moved laterally in direction of arrow A, a spray of denture base forming polymerizable material from reservoir 416 R is sprayed through heating nozzle 416 N onto denture base material layer 416 forming an incremental depth delta D of polymerizable material. The added incremental depth of polymerizable material delta D is then light cured. Some of the light for curing is emitted from curing light 442 . As the incremental depth (delta D) layer of polymerizable material is light cured it becomes integrally connected to polymeric denture base material layer 416 . Denture base forming polymerizable material from reservoir 416 R is formed by following the procedure of Preparation 3 below.
Polymeric denture base material 416 is supported by nonpolymerizable wax layer 450 . Nonpolymerizable wax layer 450 is formed by spraying nonpolymerizable wax from reservoir 450 R through heating nozzle 450 N onto transparent support 414 . Nonpolymerizable wax layer 450 serves as a scaffold for polymeric denture base material layer 416 .
In the upper portion of polymeric denture base material layer 416 sections of denture base forming polymerizable material from reservoir 416 R are replaced by tooth forming polymerizable material sprayed from reservoir 460 R is through heating nozzle 460 N onto the adjacent portion of layer 416 . This forms an incremental depth delta D of polymerizable material having sections of tooth forming polymerizable material in the layer of denture base forming polymerizable material. The added incremental depth of polymerizable material delta D is then light cured. Tooth forming polymerizable material sprayed from reservoir 460 R is formed by following the procedure of Preparation 6 below.
Above the polymeric denture base material layer 416 only the sections of tooth forming polymerizable material continue to be sprayed from reservoir 460 R is through heating nozzle 460 N to incrementally form teeth. Each incremental depth delta D of polymerizable material in the sections of tooth forming polymerizable material incrementally form teeth above the layer of denture base forming polymerizable material. These added incremental depths of polymerizable material delta D are light cured. Over the polymeric denture base material layer 416 and over outer layer of each section of each tooth polymerizable sealant is sprayed from reservoir 462 R through heating nozzle 462 N to incrementally form sealed teeth and seal denture base.
Thus, a denture is formed in accordance with a preferred embodiment of the invention by, incrementally providing polymerizable material in the shape of a denture having a denture base and artificial teeth, and curing the polymerizable material to form a polymeric denture wherein the denture base and artificial teeth are integrally connected. So, a denture is formed in accordance with the invention for example by spraying liquid polymerizable material at between 60 and 80° C. into the shape of a denture having a denture base and artificial teeth, and curing the polymerizable material during and after solidifying and cooling to ambient temperature (about 23° C.), to form a polymeric denture. The polymerizable material sprayed is preferably in the form of a focused jet sprayed from a container. Preferably a family of containers is provided each having polymerizable material with a different shade of color. Some of the containers have shades of color for denture base. Others have shades of color for forming artificial teeth. These may include filler.
Location identifying markers may be placed in the patient's mouth and/or on a cast of the patient's mouth. The markers may be used to vary the thickness of the denture base.
In a preferred embodiment a first layer of deposit dots is built up and polymerized, followed by second layer is built up and polymerized followed by subsequent layers to form a dental prosthesis. Preferred dental prostheses are teeth and dentures having integrally formed teeth and denture base.
Preferably a plurality of containers each enclosing a liquid (or readily liquifiable) pigmented photopolymerizable (light curable) material having a color (or shade) different from the color (or shade) of the material in the other containers. A plurality of colors of material are combined to control the shade the denture base and each tooth of a denture formed in accordance with the invention. Information about the color of a patient's teeth (or skin) may be used to select a color of teeth to be formed in a partial or full denture for the patient in accordance with the invention.
In a preferred embodiment of the invention a denture is made by collecting digital information regarding a mouth, and forming a denture using the information. The digital information regarding a mouth may be collected at a first location, and the denture formed at a second location using the information. Polymerizable material is used to form the shape of a denture base and artificial teeth of the denture. The polymerizable material is cured to form a polymeric denture wherein the denture base and artificial teeth are integrally connected. The polymerizable material is sprayed into the shape of the denture having a denture base and artificial teeth, before curing the polymerizable material to form the polymeric denture.
In a preferred embodiment of the invention computer-control is used to rapidly manufacture dental devices by dispensing a first liquid wax-like polymerizable material at a first set of selected locations of a target surface. The first wax-like polymerizable material is polymerized to form at least a portion of a first polymeric layer of the dental device. The second liquid wax-like polymerizable material is dispensed at a second set of selected locations of a target surface. The second wax-like polymerizable material is polymerized to form at least a portion of a second polymeric layer of the dental device. The liquid wax-like polymerizable material may be dispensed by spraying. Preferably the first wax-like polymerizable material has a first color and said second wax-like polymerizable material has a second color. Additional layers are dispensed and polymerized to complete a dental device.
In a preferred embodiment of the invention provides a process for producing a three-dimensional object from a computer data base, comprising the steps of: dispensing and polymerizing layers of wax-like polymerizable material at controlled locations to form a three-dimensional object. Preferably, at least one of said layers of wax-like polymerizable material is effectively different from another of said layers of wax-like polymerizable material in a characteristic selected from the group consisting of color, texture and composition.
A preferred embodiment of the invention provides a denture by collecting digital information regarding a mouth, and forming a denture using the information. The collection of digital information regarding a mouth may be at a first location, and the formation a denture using the information may be at a second location. Preferably the digital information is the transferred from the first location to the second location through a telephone system, or while being stored on a disk that is transferred from the first location to the second location.
A preferred embodiment of the invention provides a denture by providing polymerizable material in the shape of a denture having a denture base and artificial teeth, and curing the polymerizable material to form a polymeric denture wherein the denture base and artificial teeth are integrally connected. This may be done by spraying polymerizable material into the shape of a denture having a denture base and artificial teeth, and curing the polymerizable material to form a polymeric denture.
In the following examples, unless otherwise indicated, all parts and percentages are by weight; Lucirin TPO refers to 2,4,6-trimethylbenzoyldiphenylphosphine oxide made by BASF, and the visible light curing unit used was an Eclipse visible light curing unit, sold by Dentsply International, providing about 30 milliwatts/cm 2 of from 350 to 450 nm light.
Preparation 1
Preparation of Oligomer
A reactor was charged with 1176 grams of trimethyl-1,6-diisocyanato-hexane (5.59 mol) and 1064 grams of bisphenol A propoxylate (3.09 mol) under dry nitrogen flow and heated to about 65° C. under a positive nitrogen pressure. To this reaction mixture, 10 drops of catalyst dibutyltin dilaurate were added. The temperature of the reaction mixture was maintained between 65° C. and 140° C. for about 70 minutes and followed by additional 10 drops of catalyst dibutyltin dilaurate. A viscous paste-like isocyanate end-capped intermediate product was formed and stirred for 100 minutes.
To this intermediate product, 662 grams (5.09 mol) of 2-hydroxyethyl methacrylate and 7.0 grams of BHT as an inhibitor were added over a period of 70 minutes while the reaction temperature was maintained between 68° C. and 90° C. After about five hours stirring under 70° C., the heat was turned off, and oligomer was collected from the reactor as semi-translucent flexible solid and stored in a dry atmosphere.
Preparation 2
Preparation of Monomer
A reaction flask was charged with 700 grams of 1,6-diisocyanatohexane and heated to about 70° C. under a positive nitrogen pressure. To this reactor were added 1027 grams of 2-hydroxyethyl methacrylate, 0.75 gram of catalyst dibutyltin dilaurate and 4.5 grams of butylated hydroxy toluene (BHT). The addition was slow and under dry nitrogen flow over a period of two hours. The temperature of the reaction mixture was maintained between 70° C. and 90° C. for another two hours and followed by the addition of 8.5 grams of purified water. One hour later, the reaction product was discharged as clear liquid into plastic containers and cooled to form a white solid and stored in a dry atmosphere.
Preparation 3
Preparation of Polymerizable Denture Base Plate Material
A light curable polymerizable material was prepared by stirring at 85° C. a liquid of 98.0 grams of TBDMA oligomer of Preparation 1, 0.35 gram of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (Lucirin TPO made by BASF), 1.5 gram of solution containing 8.3% camphorquinone (CQ), 25% ethyl 4-dimethylaminobenzoate (EDAB) and 66.7% 1,6-hexanediol dimethacrylate (HDDMA), 0.1 gram of red acetate fibers and 0.05 gram of pigment.
Preparation 4
Preparation of Polymerizable Wax-Like Denture Contour Material
A light curable wax-like polymerizable dental material was prepared by stirring at 85° C. a liquid mixture of 50.5 grams of oligomer of Preparation 1, 45.0 grams of monomer of Preparation 2 and 4.0 grams of stearyl acrylate from Sartomer. To this mixture were added 0.35 gram of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin TPO), 0.1 gram of red acetate fibers and 0.05 gram of pigment concentrates. The polymerizable wax-like material formed becomes flowable at 65 to 68° C.
Preparation 5
Preparation of Polymerizable Denture Set-Up Material
A light curable polymerizable material was prepared by stirring at 85° C. a liquid mixture of 84.5 grams of oligomer of Preparation 1 and 15.0 grams of monomer of Preparation 2. To this mixture, 0.35 gram of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin TPO), 0.1 gram of red acetate fibers and 0.05 gram of pigment were added.
Preparation 6
Preparation of Polymerizable Wax-Like Artificial Tooth Resin
A light curable wax-like polymerizable dental material was prepared by stirring at 85° C. a liquid mixture of 50 grams of oligomer of Preparation 1, 30.0 grams of monomer of Preparation 2 and 20 grams of monomer of Preparation 2. To this mixture were added 0.35 gram of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin TPO), and 0.05 gram of pigment concentrates. The polymerizable wax-like material formed becomes flowable at 65 to 70° C.
Preparation 7
Preparation of Monomer
A reaction flask was charged with 168 grams of 1,6-diisocyanatohexane and heated to about 70° C. under a positive nitrogen pressure. To this reactor were added 228 grams of 2-hydroxyethyl acrylate, 0.12 gram of catalyst dibutyltin dilaurate and 0.86 grams of butylated hydroxy toluene (BHT). The addition was slow and under dry nitrogen flow over a period of two hours. The temperature of the reaction mixture was maintained between 70° C. and 85° C. for another three hours and followed by the addition of 0.9 grams of purified water. One hour later, the reaction product was discharged as clear liquid into plastic containers and cooled to form a white solid and stored in a dry atmosphere.
Preparation 8
Preparation of Monomer
A reaction flask was charged with 47.7 grams of p-tolyl isocyanate and heated to about 46° C. under a positive nitrogen pressure. To this reactor were added 48.13 grams of 2-hydroxyethy methacrylate, 0.06 gram of catalyst dibutyltin dilaurate and 0.30 grams of butylated hydroxy toluene (BHT). The addition was under dry nitrogen flow over a period of 40 minutes while the temperature of the reaction mixture was raised to 78° C. and maintained between 72° C. and 78° C. for another 1.3 hours. The reaction product was discharged as clear liquid into a plastic container and cooled to form a semi-opaque off white solid and stored in a dry atmosphere.
EXAMPLES 1A AND 1B
Table 1 shows the components and Table 2 shows the properties of the compositions of Examples 1A through 1B. The compositions of Examples 1A through 1B were prepared by mixing the components shown in Table 1 at 95° C.
TABLE 1
Example 1A
Example 1B
(grams)
(grams)
Titanium dioxide
0.385
0
Iron oxide
0.0499
0.002
Red-Brown Pigment Blend
0.0132
0.0012
Ultramarine Blue Pigment
0
0.0028
Black Dry Color Blend
0.0134
0
a blend of 82.99% ZnO, 16.18% Magnesium
0.194
0.05
carbonate, 0.62% Lithium sulfate and 0.21%
Sulfur, (sublimed powder). [115 Phosphor]
dihydroxy terepthalate acid ester
0.08
0.024
[FLU-L-BLU]
Monomer of Preparation 2
40.4
17.2
Monomer of Preparation 7
28.0
24.6
Monomer of Preparation 8
24.6
Oligomer of Preparation 1
68.16
41.6
Lucirin TPO
0.6
0.32
Camphorquinone
0.32
0.212
N,N-dimethyl-aminoneopentyl acrylate
1.11
0.74
Methacrylic Acid
0.55
0.368
Butylated Hydroxytoluene
0.03
0.02
γ-methacryloxypropyl-silane
0.39
0.26
silanated fumed silica*** (SiO 2 )
28.54
6
silanated barium aluminoflurosilicate
228.39
168
glass (BAFG)**
silanated barium aluminoflurosilicate
114.19
116
glass (BAFG)*
*Barium glass particles having an average particle size of from about 1 to about 10 micrometers.
**Barium glass particles having an average particle size of from about 0.1 to about 1 micrometers.
***Fumed silica having an average particles size of from about 0.01 to about 0.04 micrometers.
The physical properties of the material of Examples 1A and 1B were tested and results listed in Table 2:
TABLE 2
Property
Example 1A
Example 1B
Localized Wear - mm 3
0.021
Flexural Strength - psi
19,600
17,330
Flexural Modulus - kpsi
1,625
1,580
Compressive Strength - MPa
358**
Water Sorption - μg/mm 3
14.9
**Compressive Strength was measured using 50 kN load cell set to run at 2,000 pounds with crosshead speed at 2 inches (50.8 mm)/per minute. Compressive strength testing specimens were prepared by following the procedure of U.S. Pat. No. 6,387,981. Each composite was packed into a 4 mm inside diameter glass tube, capped with silicone rubber plugs and axially compressed at about 0.28 MPa for 15 minutes, then light cured for 10 minutes in Eclipse light curing unit (voltage at 37.5 V, blowers at 80 percent). Cured samples were cut on a diamond saw to form cylindrical plugs 8 mm long and stored in distilled water at 37° C. for 24 hours and then measured for compressive strength.
A three body cyclic abrasion wear machine (Leinfelder/University of Alabama in vitro) was used to determine volume loss (cubic mm at 400,000 cycles), as a measure of the wear resistance of the polymerized composite compositions of Examples 1A and 1B.
Water sorption of the polymerized composite compositions of Examples 1A and 1B was measured according to ISO 4049. The samples were cured for 10 minutes in the Eclipse light curing unit (voltage at 37.5 V, blowers at 80% from 5:30-10:00 minutes). Flexural Strength and Flexural Modulus of the polymerized composite compositions of Examples 1A and 1B were measured by using three-point bend test on Instron bending unit according to ASTM D790 (1997). Samples were cured in metal molds in an Eclipse light curing unit for 10 minutes (voltage at 37.5 V, blowers at 80% from 5.5-10 minutes).
EXAMPLE 2
Continuous Tooth Making
Two steel disks each has a cylindrical outer face with a sequence of tooth mold halves therein. The two steel disks are rotated so that they are in contact along their outer cylindrical faces. The corresponding tooth mold halves on each disk are aligned while their portions of the cylindrical outer faces are in the contact. A sheet of polymerizable wax-like material at 60° C., formed by following the procedure of Preparation 6, is continuously fed between the aligning outer faces of the two rotating steel disks, each at 37° C. The corresponding tooth mold halves on each disk shape 0.5 g to 2 g portions of the polymerizable wax-like material into artificial teeth as they rotate into alignment with each other.
EXAMPLE 3
Multiple Layered Tooth Making
Each of two steel mold halves has fourteen half tooth molds therein. The two steel mold halves (each at 37° C.) are positioned in contact, with the corresponding half tooth molds aligned, and a sheet of polymerizable wax-like composite material (at 60° C.) positioned between the aligned faces of the two mold halves. The polymerizable wax-like composite material is formed by following the procedure of Example 1B. The corresponding tooth mold halves shape 0.3 g portions of the polymerizable wax-like composite material into each of the enamels of artificial teeth as they are aligned with each other. One steel mold half (without enamels of artificial teeth) is removed and an additional steel mold half (at 37° C.) applied in its place, so that the mold halves are in contact along their mold outer faces. The additional steel mold also has fourteen half tooth molds therein. A sheet of polymerizable wax-like composite material at 60° C., formed by following the procedure of Example 1A, is positioned between the two mold halves. The polymerizable wax-like composite material is forced into the tooth mold cavities. The corresponding tooth mold halves shape 1 g portions of the polymerizable wax-like composite material (at 60° C.) into each of the artificial tooth bodies. Each artificial tooth body combines with the enamel in its mold cavity to form a two layer artificial tooth.
The fourteen teeth formed are positioned into a molded denture base of material prepared by following the procedure of Preparation 3, and light cured by impinging light thereon for 60 seconds from a Spectrum 800 light curing unit (sold by Dentsply International Inc), followed by curing for 10 minutes in a Triad 2000 light curing unit (sold by Dentsply International Inc). The adjacent surfaces of the teeth and the denture base combine during polymerization to form an integral denture.
EXAMPLE 4
Continuous Multiple Layered Tooth Making
Each of two steel disks has a sequence of fourteen half teeth molds in its cylindrical outer face. The two steel disks (each at 37° C.) are rotated so that they are in contact along their outer cylindrical faces, with the corresponding half tooth molds aligned, as a sheet of polymerizable wax-like composite material (at 60° C.) continuously fed between the aligned faces of the two disks. The polymerizable wax-like composite material is formed by following the procedure of Example 1B. The corresponding tooth mold halves shape 0.3 g portions of the polymerizable wax-like composite material into each of the enamels of artificial teeth as they are rotated into alignment with each other. One steel disk without enamels of artificial teeth is removed and an additional steel disk (at 37° C.) put in its place, so that the mold halves are in contact along their mold outer faces as they are rotated. The additional steel disk also has fourteen half tooth molds therein. A sheet of polymerizable wax-like composite material at 60° C., formed by following the procedure of Example 1A, is continuously fed between the two disks. The polymerizable wax-like composite material is forced into the tooth mold cavities. The corresponding tooth mold halves shape 1 g portions of the polymerizable wax-like composite material (at 60° C.) into artificial tooth bodies. Each artificial tooth body combines with the enamel in its mold cavity to form a two layer artificial tooth.
The fourteen teeth formed are positioned into a molded denture base of material prepared by following the procedure of Preparation 4, and light cured by impinging light thereon for 10 minutes in an Eclipse light curing unit, sold by Dentsply International Inc. The adjacent surfaces of the teeth and the denture base combine during polymerization to form an integral denture.
EXAMPLE 5
Preparation of a Denture without Forming a Mold Cavity of a Denture Base
A plaster cast of a patient's mouth is coated with a release agent (e.g., Al-Cote and Isolant sold by Dentsply International Inc. or Teflon solution such as Krytox from Dupont) and heated to 55° C. in an incubator. An arch-shaped baseplate resin containing 14 grams of the product of Preparation 3 is applied and shaped onto the warm cast. The resin is shaped and flowed to fully cover the cast, using finger pressure and trimming to form a baseplate. The baseplate is cured for 10 minutes in the visible light curing unit. A sufficient quantity of the product of Preparation 5 is formed into a rope. The rope is applied to the baseplate. Artificial teeth formed by following the procedure of Example 3 are then pressed into the rope with the thickness of the rope adapted to adequately cover the appropriate surfaces of the teeth to provide support. Melted product of Preparation 4 from an about 87° C. wax pot is applied by using an electric spatula between the teeth and the baseplate to fully embed teeth and to flow into fissures between teeth and to smooth the outer surface of the denture. Hot air from a small nozzle hot air gun may also be applied to let the product of Preparation 4 flow into fissures between teeth and smooth the outer surface of the denture. The lingual and buccal surfaces of the denture are contoured, trimmed and carved using a spatula. The denture is placed in a patient's mouth for try-in at a dental office, the tooth positions are adjusted. The uncured teeth are carved, trimmed, melted and softened to adjust their horizontal and vertical positions and shapes. The denture back (tissue side) is filled with fresh plaster and allowed to set. TRIAD Air Barrier Coating is painted on the dentureand cured in an Eclipse visible light curing unit (sold by Dentsply International) for 10 minutes. The artificial teeth are integrally connected to the denture base. When cured, the denture is washed with water to remove all traces of Air Barrier Coating. The denture is then finished and polished.
EXAMPLE 6
Preparation of Oligomer
A reactor was charged with 150 grams of 1,6-diisocyanatohexane and 200 grams of bisphenol A propoxylate under dry nitrogen flow and heated to about 56° C. under positive nitrogen pressure. To this reaction mixture, 0.12 gram of catalyst dibutyltin dilaurate was added. The temperature of the reaction mixture was maintained between 65° C. and 80° C. for about 3.5 hours. To this isocyanate end-capped intermediate product, 82.96 grams of 2-hydroxyethyl methacrylate and 2.15 grams of BHT as an inhibitor were added over a period of 50 minutes while the reaction temperature was maintained between 55° C. and 75° C. After about five hours stirring, the heat was turned off, and oligomer was collected from the reactor as semi-translucent flexible solid and stored in a dry atmosphere.
Preparation of Wax-Like Spray Tooth Making Material
Wax-like Spray Tooth Making Material is formed by mixing the at from 85° C. 29.5 g oligomer made by following the above procedure of this example (for Preparation of Oligomer), 19.7 g Cyclohexane dimethanol diacrylate, 1.4 g Shading Pigments, 0.1 percent camphorquinone, 0.1 g 2,4,6-trimethylbenzoyl-diphenylphosphine oxide,
18.6 g silanated barium aluminoflurosilicate glass (BaBFAISiO 4 ): a mean particle size from 4 to 7 (micron) and a maximum particle size of 50 (micron), 26.7 g silanated barium aluminoflurosilicate glass (BaBFAISiO 4 ): a mean particle size of 0.92-0.96 (micron) and a maximum particle size of 3.75 (micron), 3.9 g silanated fumed silica (SiO 2 ). The polymerized product has 0.013 mm 3 wear volume loss at 400,000 cycles. The cooled material is then light cured by impinging light thereon for 30 seconds from a light curing unit (Spectrum 800 sold by Dentsply International Inc).
It should be understood that while the present invention has been described in considerable detail with respect to certain specific embodiments thereof, it should not be considered limited to such embodiments but may be used in other ways without departure from the spirit of the invention and the scope of the appended claims. | This invention relates to methods for making a three-dimensional dental prosthesis using ink-jet printing systems. An ink-jet printer is used to discharge light-curable, wax-like polymerizable material in a layer-by-layer manner to build-up the prosthesis. The methods are particularly useful for making integrated dentures containing a set of artificial teeth. The denture base and set of teeth are made of light-curable, wax-like polymerizable materials comprising a mixture of monomer, oligomer, and light sensitizer. The wax-like materials are dimensionally stable in their uncured states. The denture base and artificial teeth are later light-cured to form a polymerized denture product having high flexural modulus and flexural strength. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a tumbler dryer with a container for articles to be dried (such as clothes or other fabrics), which is arranged to be traversed by hot air during the drying process and where, at the beginning of the drying process, the temperature of the exhaust air from the container increases relatively rapidly and thereafter increases more slowly or remains constant, and where, towards the end of the drying process, the rate of increase of the temperature starts increasing.
In tumbler dryers it is of importance to be able to terminate the drying process when the moisture content of the articles has reached the desired value. If the drying is interrupted too early, the moisture content is too high with the consequent apparent disadvantages. If the drying is interrupted too late, this involves an unnecessarily high energy consumption, and the too low moisture content of the articles will increase their propensity to wrinkle and make them difficult to iron, and further the risk of static electric charging of the articles will increase. There are therefore considerable advantages to be gained if the drying process can always be terminated at such a time that the dried articles have the desired moisture content. The desired value of the moisture content may vary between, for example, 1-3% (for normal dry laundry) and 8-11% (for iron dry laundry), depending on the subsequent treatment to which the dried laundry is intended to be subjected.
It is previously known to provide tumbler dryers with a simple time program which interrupts the drying after a preset time. Since the rate of drying is very much dependent on several factors, for example the amount of articles to be dried in the container and the material of the articles, it is impossible in practice to predict and set, in a certain case, the drying time which in that particular case gives the desirable moisture content. The dried laundry will therefore have too high or (more often) too low a moisture content, resulting in the above-mentioned disadvantages.
Further, it is known to arrange a temperature sensor which senses the temperature of the exhaust air from the drum-washer. When the tumbler dryer is started, this temperature first increases relatively rapidly and then becomes constant or increases more slowly, while the main portion of the water content of the laundry is driven off. Towards the end of the drying, the temperature starts rising again (or starts rising more rapidly). It is known to arrange members which are influenced by the temperature sensor and which automatically terminate the drying process (the supply of hot air to the drum) when the temperature of the exhaust air during the final stage of the drying has reached a predetermined value, for example 60° C., which may then be suitably selected so that a certain moisture content in the laundry is obtained at full load of the tumbler dryer. However, there is no clear relationship between moisture content and switch-off temperature, and therefore it is not possible in each individual case, by setting the switch-off temperature, to determine what moisture content the laundry will have at the end of the drying. Further, it has proved that when the drum of the machine is only partly filled, the drying will take place more rapidly, and when the exhaust air reaches the switch-off temperature, the moisture content of the laundry is considerably lower than what is the case at full load. At partial load, the drying will therefore be interrupted too late, which results in the disadvantages mentioned in the introduction.
It is also known to sense the temperature of the articles to be dried and the temperature of the air current, and terminate the drying when the difference between these two temperatures drops below a predetermined limit value. In another known method, the drying is terminated when the rate of change of the temperature of the articles or of the exhaust air exceeds a predetermined value. Both these methods involve the drawback that the moisture content of the articles towards the end of the drying becomes greatly dependent on the amount of articles in the container.
To avoid the drawbacks with the above-mentioned methods, it is known to arrange electrodes in the drum and measure the resistance between the electrodes continuously during the drying process. During the rotation of the drum the articles are brought into contact with the electrodes, and the measured resistance becomes dependent on the resistivity of the articles and thus on the moisture content of the articles. As the drying progresses the moisture content is reduced, the resistivity increases and thus the measured resistance value also increases. When this value has reached a predetermined level, the drying is interrupted. However, this method involves several disadvantages. Particularly at low moisture content, it is difficult or impossible to determine, with sufficient accuracy, the moisture content by measuring the resistance in the described manner. Further, the mechanical-electrical design will be complicated (slip rings are required for transmitting the measuring signal). In case of mixed load, for example synthetic and cotton garments, the synthetic garments will dry first. It has proved that in this case the drying is normally not interrupted until the last cotton garment has become dry. The synthetic garments will then become dried to too great an extent, and synthetic material is often very sensitive to this. Another disadvantage of the method of measuring resistance is that the measured resistance, in addition to being influenced by the moisture content of the articles, may also be greatly influenced by lime deposits, etc., on the measuring electrodes and by the conductivity and the degree of purity of the water.
The invention aims to provide a tumbler dryer in which, in a simple and reliable manner and with great accuracy, a preset moisture content of the articles is obtained at the end of the drying process. The resulting moisture content shall be able to be set at different values. It should, as far as possible, be independent of the amount of articles in the drum and of the material of the articles, and it should also be independent of the temperature of the inlet air, which may be influenced by variations in the mains voltage, etc.
What characterises a tumbler dryer according to the invention will be clear from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the invention will be described in greater detail with reference to the accompanying drawings.
FIG. 1 shows schematically an example of a tumbler dryer according to the invention.
FIG. 2 shows in more detail the control circuits of the tumbler dryer according to FIG. 1.
FIG. 3 shows the temperature of the exhaust air as a function of the time during a drying process.
FIG. 4 shows an example of a flow chart for the program for the microprocessor included in the control circuits according to FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a tumbler dryer with a container for articles to be dried in the form of the perforated rotary drum TR. The inlet air is supplied through an air channel LI and then passes through an electric heating element E. After passing through the drum TR, the air stream passes through the exhaust channel LU. A fan F is arranged in said channel, which fan drives the air stream through the channels and the drum. Further, a temperature sensor G is arranged at the exhaust channel LU. Said sensor may consist of a thermistor, a thermocouple or other suitable sensor, and it is located so as to emit a signal which is a measure of the temperature T of the exhaust air. The fan and the drum are driven by a common electric motor M which, as the element E, is supplied from a control unit S.
The operating members of the tumbler dryer are connected to the control unit and consist of a start button ST and a moisture selector FV. The latter is schematically shown as four switches activated by a common handle, or the like, each of said switches being able to assume two positions. In one position the switch supplies a positive voltage (which may be a logical "one") to the control unit S, and in the other position the switch supplies the voltage zero (a logical "zero"). With the help of the selector FV and its four switches, the desirable moisture content may be set at 2 4 =16 different positions. A microswitch LK is adapted to be influenced by the lid of the tumbler dryer and thus supplies the control circuits with information whether the lid is opened or closed.
FIG. 2 shows in more detail an example of the design of control unit S in FIG. 1. The core of the control unit is the microprocessor MP, for example of the Texas Instruments 9940 type. The processor receives information from the moisture selector FV about the set moisture content, from the lid switch LK, from the start knob ST and from the temperature sensor G about the temperature of the exhaust air. The sensor G is connected to the processor via an analog-digital convertor A/D. If necessary, of course, components LK, ST and FV may be connected to the processor via members which convert the signals from these components into signals adapted to the processor.
The processor is pre-programmed to store and process information from members FV, LK, ST and G (see further flow chart in FIG. 4 and, as a result, emit signals for switching on and off element E and motor M. These signals are emitted via output members U1 and U2 to contactors R1 and R2, by means of which the motor and the element may be connected or disconnected from the mains voltage (220 V). Output members U1 and U2 may comprise optoswitches for obtaining galvanic separation and amplifiers for operating the contactors. These are shown in FIG. 2 as electromagnetic electric switches, but as an alternative they may consist of static coupling members, for example thyristors.
FIG. 3 shows the temperature T of the exhaust air as a function of the time t during a drying procedure in a tumbler dryer. At t=O, the drying is started, the motor M and the element E are switched on, and a stream of hot air is blown through the drum TR. The temperature T of the exhaust air first increases relatively rapidly. According as the air channels, the drum and the articles are heated, the rate of increase of the temperature decreases and at time t 1 it reaches a relatively constant level T'. The continuous curve in FIG. 3 shows a typical characteristic at full load. For the time t 1 -t 2 , the main part of the water contents of the articles is driven off. When there is only a small amount of water left, the temperature T starts increasing (at t=t 2 ) and approaches a new limit value which is considerably higher than T' if the hot air injection is not interrupted.
If there is a smaller quantity of articles in the drum, the entire drying process proceeds more rapidly that what is shown in FIG. 3. Further, the interval t 1 -t 2 , at which the temperature T is constant, may be shortened or completely disappear (see the dash-dotted curve in FIG. 3). However, as in the continuous-line curve, the temperature first increases relatively rapidly, The rate of increase first decreases successively and then (at t=t 2 '), when the major part of the water has been driven off, starts increasing again.
The invention is based on the realization that very considerable advantages are gained if the drying is terminated when the temperature has risen by a predetermined amount above the temperature which prevailed when the rate of increase of the temperature started increasing. The continuous-line full load curve in FIG. 3 shows that the rate of increase of the temperature starts increasing at t=t 2 . The temperature (T') at this time is stored, and when (at t=t 3 ) the temperature has risen by a predetermined amount T 2 above the stored value, that is when T=T'+T 2 , the supply of hot air to the drum is interrupted. At partial load, the temperature (T") is in the same way stored at the time (t 2 ') when the rate of increase of the temperature starts increasing, and when (at t=t 3 ') the temperature has risen by the predetermined amount T 2 above the stored temperature T", the supply of hot air is interrupted.
It has proved that, largely independent of the amount of the articles and the material included (synthetic fibres, cotton, etc.), there is a very good correspondence between the temperature increase T 2 in FIG. 3 and the moisture content of the articles at the end of the drying. By designing the tumbler dryer so that a value of T 2 may be set prior to the drying which corresponds to the desirable moisture content at the end of the drying and so that the drying process is interrupted when the temperature of the exhaust air has increased by the set amount above the temperature which prevailed when the rate of increase of the temperature started rising, it is thus possible to obtain a desired moisture content at all times with great accuracy, independent of the amount of articles and independent of the material or materials of which the articles consist. It has also proved that in this way the desired moisture content is obtained with great accuracy also at such variations of the temperature and velocity of the inlet air that may be caused by, for example, variations in the mains voltage.
It has been found that in a typical machine the following relationship prevails between moisture content and temperature increase T 2 :
______________________________________moisture content T.sub.2percent °C.______________________________________1-3 15 8-11 315 1______________________________________
Thus, the moisture selector FV may be graded by moisture content or with another suitable text but be designed so that the microprocessor is supplied with a value of T 2 which corresponds to the set moisture content.
FIG. 4 shows an example of a flow chart for the program for the microprocessor MP in FIG. 2 and by means of which the tumbler dryer may be controlled so that the function according to the invention is obtained. First the desired value of T 2 is set by means of moisture selector FV, and then the start button ST is pressed. The program is then started and the motor M is switched on. Thereafter it is checked if the lid of the machine is closed. If that is the case, the element E is switched on. Thereafter it is checked whether the variable Δ 3 T is greater or equal to the set amount T 2 . This variable is (see further below) equal to the temperature increase above the temperature (e.g. T' or T" in FIG. 3) at which the rate of increase of the temperature starts rising. Δ 3 T is set to zero at the beginning of the program and therefore Δ 3 T<T 2 until the drying process is to be terminated. The program therefore returns to the control "Lid closed" and runs around this loop until Δ 3 T≧T 2 , when the program goes to "Stop", element E and motor M then being switched off. If, before this, the program finds out that the lid is not closed, the program also proceeds to "Stop", and the motor and the element are switched off.
In addition to the main program described above, the program also includes a calculating program for calculating the variable Δ 3 T. This program is also started when the start button is activated. The program is arranged to sense the temperature T at times 0, τ, 2τ, 3τ, etc. (see FIG. 3), that is, the sampling interval is τ. τ may, for example, be 10 seconds. The calculating program operates with the following variables:
T--temperature at the time of sensing.
T 1 --temperature at the preceding sensing occurrence.
Δ 1 T--immediately preceding value of the temperature increase during a sampling interval.
Δ 2 T--the difference between the last and the immediately preceding value of the temperature increase during a sampling interval.
Δ 3 T--the difference between the present temperature and the temperature (e.g. T' in FIG. 3) at which the rate of increase of the temperature starts increasing.
Δt--time elapsed since the immediately preceding sensing of the temperature.
Upon starting, i.e. at t=0, the variables Δ 2 T and Δ 3 T are set to zero, and T1 is set equal to T. For as long as Δt<τ(τ is the sampling interval, see FIG. 3) thereafter, the program runs around in a loop. At t=τ, Δt=τ and the program computes and stores Δ 1 T=T-T 1 , which is the temperature increase during the first sampling interval. After the time Δ, i.e. at t=τ the program proceeds and computes Δ 2 T=T-T 1 -Δ 1 T. T-T 1 is the temperature increase during the interval t=τ until t=2τ. Δ 2 T is an approximate measure of the second differential of the temperature with respect to the time. Since the temperature at the initial stage increases successively slower, Δ 2 T is negative at this stage. The condition Δ 2 T>0 is therefore not fulfilled and the program takes the right-hand direction in the figure and stores the current values of Δ 1 T and T 1 . After the time τ, i.e. at t=3τ, a renewed computation of Δ 2 T is made. For as long as Δ 2 T≦0, the program runs around once every sampling interval in the loop now described. At t=t 2 (or t=t 2 ') in FIG. 3, however, the rate of increase of the temperature starts increasing. Δ 2 T then becomes positive and the program continues downwards in FIG. 4. First T 1 =T is set, that is, the stored value of the variable T 1 constitutes the temperature level (T' or T" in FIG. 3) above which the temperature increase T 2 shall be measured. The program therefore enters a closed loop and causes the quantity Δ 3 T to become computed once every sampling interval. For Δ 3 T, Δ 3 T=T-T 1 , where Δ 3 T is a measure of the temperature increase above the reference level stored as the variable T 1 .
When Δ 3 T amounts to the set value of T 2 , the drying is interrupted in the manner described above with reference to the description of the main program.
The above-described embodiment of a tumbler dryer according to the invention is merely an example and many other embodiments are feasible within the scope of the invention. The computing program for fixing the time at which the rate of increase of the temperature starts rising may, of course, be different from that described above and may, for example, be made more sophisticated such that the effect of minor random temperature fluctuations is eliminated. Similarly, the program of the machine may be extended so that only the element E is switched off at time t 3 (t 3 ') in FIG. 3. After this time, thus, non-heated air is blown through the drum, thus cooling the articles. The machine may then be arranged to stop when the temperature of the exhaust air has dropped to a suitable predetermined value, for example 25° C. Possibly, this cool-down stage may be succeeded by a stage at which the motor is run intermittently during short intervals to prevent wrinkling of the articles. | To secure a desired value, preferably adjustable in advance, of the moisture content at the end of the drying process, independent of the amount of articles to be dried and of the material of these articles, a tumbler dryer may be provided with a temperature sensor (G) which senses the temperature (T) of the exhaust air from the drum (TR). The tumbler dryer is provided with control members (S) which determine the value of the temperature at the time when the rate of increase of the temperature during the latter stage of the drying process starts increasing, and which terminates the supply of hot air to the drum when the temperature has risen by a preset amount, corresponding to the desired moisture content, above said value. (FIG. 1.) | 3 |
COPYRIGHT NOTICE
[0001] A portion of the disclosure of this patent document, including Appendices, contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to an apparatus (an article of manufacture) and method of use. The present invention particularly relates to structure restraint systems and accessories used in conjunction therein. The present invention more particularly relates to a device, system and method of using a structure restraint system to solve the problem of roof and/or structure damage due to inclement weather, natural forces and acts of God.
DESCRIPTION OF THE PRIOR ART
[0003] Internal restraint systems are commonly used in modern buildings to resist wind, earthquake and other loads. Especially in south Florida and the Gulf of Mexico, which had record hurricanes in 2004, the building codes are increasingly becoming required to enable buildings and structures for 140 MPH (miles per hour) wind loads.
[0004] Accordingly, it is understood that one skilled in the art would know that most new building codes in high-wind areas require the structure to be physically connected contiguously from the roof to the foundation. The old art uses “hurricane clips” to tie the rafters or trusses to the top of the bearing wall and the bearing wall then anchored to the foundation. This generally works well but not when needed in emergencies during the time of high wind and/or other natural forces exceed normal design specifications, i.e. the few days during which the hurricane path is close enough to impart destructive wind forces exceeding design strength. It is expensive and inefficient to design and build buildings and/or structures (houses, offices, warehouses, storage buildings, industrial plants, retail stores, aircraft hangars, etc.) for the maximum need (140 MPH or higher) when this strength is only needed a rarely for a few days at a time. Additionally, older homes were designed to withstand much lower speed winds and need an external emergency restraint system to enhance the roof's resistance to 140 MPH wind force, such as this invention accomplishes.
[0005] Also, previous devices and systems also do not prevent the loss of typical residential roof shingles. The problem to be solved is preventing roof shingles from being “stripped” from a sloped roof by the high winds for short periods of time. Thus, a need exists in the industry for a device and system that may be quickly installed externally to be used in these relatively short durations of high climatic forces. Versions of this new and useful invention solve this need.
[0006] U.S. Pat. No. 6,722,085 discloses a Mobile Home Tie-Down Apparatus.
[0007] No prior art is known to this inventor that discloses a selectably attachable emergency device and/or system installed externally over the structural skeleton that makes it possible to restrain roof shingles, roofs and buildings/structures under emergency climatic conditions while attached, then released, removed and stored for future use during normal climatic conditions. Since versions of the device and system are only utilized during the actual times needed, the aesthetics of the building/structure are unchanged during average wind conditions. This new and useful invention solves the problems of securely restraining roof shingles, roofs, and buildings/structures, alone or in combination, during emergency climatic periods when needed while not affecting the artistic elements of the building/structure when not needed.
BRIEF SUMMARY OF THE INVENTION
[0008] It is an object of the benefits and features of versions of this invention to help prevent the “stripping” of shingles from building/structure roofs during high winds.
[0009] It is another object of the benefits and features of versions of this invention to help restrain the roof, roof system and building/structure during high winds and other types of inclement weather with a releasably attached external structure restraint system that may be removed and stored when not needed.
[0010] At least one, some or all of the objects of this invention are achieved, in several embodiments, with this new and useful emergency external structure restraint device and system. This external structure restraint device and system is lightweight, compact when stored and of simple construction that is easy to make and use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the manner in which the above-recited and other advantages and objects of versions of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
[0012] FIG. 1 is a sectional view of an embodiment of the external structure restraint device and system constructed in accordance with one embodiment of the present invention, showing an eave with no overhang. Eaves with overhangs may also be used.
[0013] FIG. 2 is a plan view of an embodiment of the external structure restraint device and system constructed in accordance with one embodiment of the present invention.
[0014] FIG. 3 is a sectional view of an alternate embodiment showing the plurality of earth anchors connected to tension members attached to the external roof net, tightened for emergency use.
[0015] FIG. 4 is a plan view of an alternate embodiment showing the plurality of earth anchors connected to tension members attached to the external roof net, tightened for emergency use.
[0016] FIG. 5 is a plan view showing the continuous ridge cushion(s) and continuous eave cushion(s) under the external roof net.
[0017] FIG. 6 is a sectional view of an arch-type structure with the external roof net used with or without additional tension members and earth anchors or alternately earth anchoring into the foundation of the structure.
[0018] FIG. 7 is a sectional view of a structure with crawl space on pier foundations with at least one earth anchor set in a predetermined location upwind to resist a particular wind force vector.
[0019] While the present invention will be described with reference to the details of the embodiments of the invention shown in the drawings (and some embodiments not shown in the drawings), these details are not intended to limit the scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The apparatus of the invention is conveniently fabricated in the preferred embodiment by conventional and standard methods of fastening, weaving, winding, seaming, installing, joining and finishing in the metal, wire, netting, textile and earth anchoring fabrication arts using conventional and standard materials.
[0021] For example, the external structure restraint device and system and incorporated components may be fabricated from wood, aluminum, steel, stainless steel and/or other like metals or any other suitable material as will be readily apparent to one of ordinary skill in the art. Versions of the present invention (or components of) may also be fabricated in best mode from non-metallic materials for lighter weight, reduced cost and resistance to corrosion. These non-metallic materials include, among others, conventional polymers such as, for example, polystyrene, polycarbonate, polyurethane, polyethylene, phenol formaldehyde resins, polybutylene, Teflon and the like.
[0022] Plastics (any one of a large and varied group of materials consisting wholly or in part of combinations of carbon with hydrogen, oxygen, nitrogen and other organic and inorganic elements; while solid in the finished state, at some stage in its manufacture, it is made liquid, and thus capable of being formed into various shapes, usually through the application of heat and/or pressure), such as monomer (one unit—the building block for polymer molecules) or polymer (many monomer units strung together to make long molecules) used in polymerization (the process of combining short molecules to make long molecules) may be used.
[0023] Thermoplastics (plastics that can be repeatedly softened and hardened by heating and cooling) as well as Thermosets (plastics that are cross-linked during polymerization and cannot be softened without degrading some linkages) may also be used.
[0024] Thermoplastic resin types such as crystalline (thermoplastics containing areas of dense molecular alignments known as crystallinity), amorphous (thermoplastics with no crystallinity in the solid state), liquid crystal polymers (LCPs) (stiff, rod-like structures organized in large paralleled arrays in both melted and solid states) may also be used.
[0025] All components may be referenced in plural for convenience, as only at least one of all components are necessary, if desired, for proper operation and use in other embodiments. Ideally, all components (or some components) are fabricated from non-metallic materials as previously mentioned above. Other materials and methods that can be used are stainless steel cables, textile threads made from materials standard in the textile industry such as nylon webbing, nylon thread, Kevlar thread, cotton thread, canvas material, nets and/or netting materials made from any of the above-referenced materials, which is meant to be illustrative and not intended to be limiting as to the types of materials that may be used to practice versions of the invention. These materials may be formed into thread, strap, rope, net, web, band, cord, string, leash, belt, braid, mesh and pliable membranes.
[0026] The earth anchor may be fabricated from suitable metal in the form of screw-anchors for mobile homes, flap-type anchors, concrete foundation or other type means for anchoring. For example, an earth anchor such as one available by General Supply, 3902 Hanna Circle—Suite A, Indianapolis, Ind. 46241, Phone: (317) 856-4300, Toll Free: (800) 479-2754, Fax: (317) 856-1012, Email: customersvc@generalsupplyinc.com, the ¾″×30″ E-Z Set Anchor by Tie Down Engineering. Other Tie Down Engineering, Inc. (5901 Wheaton Drive, Atlanta, Ga. 30336) models that may be used are models MI 2H, MI 2H6, MI 22, MRA, MRAX 48 and related accessories, which are listed as illustrative only and not intended to be limiting as to the types of earth anchors that may used to practice versions of the invention. Appendix A attached also list other anchors which may be used, which are listed as illustrative only and not intended to be limiting as to the types of earth anchors that may used to practice versions of the invention. All anchors with suitable resistance to the desired climatic forces may be used. All components of the device and/or system are of sufficient strength to resist the desired climatic forces, i.e., wind speeds of 100 MPH, 120 MPH, 140 MPH or higher or any desired wind resistance strength.
[0027] Now, an overall description of the method of making and using one version of the invention will be described in detail. In one embodiment, as depicted in FIG. 1 and FIG. 2 , at least one tension member, of sufficient strength to resist the desired climatic forces, further comprising a first tension member 10 (with a roof end 12 and an earth end 13 ) is attached to an attachment means 40 on an earth anchor means 41 (typically a mobile home screw-type anchor). The roof end 12 of the first tension member 10 is attached to the top tension member 14 over an eave cushion 20 disposed over the first roof eave 33 (with or without overhang) at the top of the bearing wall 32 which bears on the foundation 33 . The top tension member 14 then is looped over the roof surface 30 and perpendicular to the roof ridge 31 over a ridge cushion 21 and then to another eave cushion 20 on the second roof eave 34 (with or without overhang), attached to the second tension member 15 which is attached to the attachment means 40 on another earth anchor means 41 .
[0028] An optional means for adjusting 11 (such as a ratchet, pulley, friction device, come-along, turnbuckle and/or other suitable adjusting/tensioning device) may be used to tighten the system after installation to the desired-tautness. The means for adjusting may also be a spring-biased locking knob (with or without a plurality of longitudinally disposed apertures on an elongated length-adjustable bar), belt-buckle (with or without a plurality of longitudinally disposed apertures on an elongated length-adjustable bar), snap, fastener, touch-fastener (Velcro), quick-release mechanism or any other means for adjusting, all well known in the art as of today.
[0029] Alternately, the external tension member may be one continuous tension member 16 (as shown in FIG. 7 ) comprising the first tension member 10 , top tension member 14 and second tension member 15 and optional bottom tension member 17 all combined to comprise a single tension member, with or without a means for adjusting.
[0030] To install and use one version of the invention on a structure, typically the operator would first install the two earth anchors 41 on opposite ends of the structure as shown in FIG. 1 and FIG. 2 . Then, for example as shown in FIG. 1 , the first end of an external continuous tension member 16 (comprising the first tension member 10 , top tension member 14 and second tension member 15 all combined, without the optional bottom tension member 17 in this example, to comprise a single tension member) is attached to the attachment means 40 on an earth anchor means 41 . The continuous tension member 16 is looped over the eaves ( 33 and 34 with or without overhang(s)) and roof ridge 31 and over the eave cushions 20 and ridge cushion 21 after first positioning the cushions in a preconfigured arrangement under the continuous tension member 16 , and then attached to the other earth anchor means 41 , also depicted in FIG. 1 and FIG. 2 . The at least one means for adjusting 11 (previously integrated into the continuous tension member 16 ) is tightened and the system is ready for use.
[0031] To uninstall and remove this version of the invention from the structure, if desired, the above-referenced installation procedure is reversed.
[0032] Another embodiment uses an external net anchored to at least one, a plurality or several earth anchor means as shown in FIG. 3 , for the external tension member. The size of the net openings may be of any size but should be scaled to cover the average size of a residential roof shingle when used on houses, as shown in FIG. 4 . For instance, the net opening could be sized to accommodate a typical residential roof shingle such as the standard 3-tab Sentinel Shingles manufactured by GAF Materials Corp. 1361 Alps Road, Wayne, N.J. 07470, (973)628-3000, which has an exposed surface of about 5 inches and about 13 inches wide. A net, for example, with openings of about 3 inches square would be sufficient for use in this application. Netting products such as those made by Global Net Service, Shengqun Zhou, 5-404 Nantong Road, Taizhou, Jiangsu Province, China 225300, Tel: 86-13901431072, Fax: 86-523-6666567, Email: sales@global-net-service.com may be used in versions of this invention. Nets have the advantage of allowing the high wind force to penetrate the net's surface (as do pliable mesh membranes, which also may be used) while restraining the roof shingles underneath the external net or external pliable mesh membrane from separating from the sub-roof, well known in the art.
[0033] These include fishing nets, fish nets, gillnets ropes, twines, cargo nets, construction and safety nets, sports nets, fishnets, hammocks, farming nets and ready to use nets which may be used in versions of the invention. Other types that may be used include: twisted knotted polyethylene & nylon nets, single strand, very strong and flexible and easily repaired, available in single or double knot; braided knotted nylon netting, which is more abrasion resistant than twisted netting, not quite as strong as twisted netting, more difficult to repair, more expensive, available in many colors and sizes (as are most nets); knotless nettings available in many sizes, lengths, and depths; monofilament nylon fishing net which is very similar to the twine commonly used in fishing reels, more abrasion resistant than multifilament netting, easily cleaned of debris, available in single, double knot, absorbs very little water (valuable in hurricane rains), available in many colors and sizes, all of which are listed as illustrative only and not intended to be limiting as to the types of nets or mesh pliable membranes that may used to practice versions of the invention.
[0034] All types of tie downs (as they are commonly known in the industry), with or without a means for adjusting, may be used as the tension member(s), such as those available at www.Alibaba.com on the World Wide Web (WWW). These include ratchet tie downs, industrial safety belts, lashing strap belts, high-intensity polyester belts, web sling belts, polyester webbing slings, rigging hardware, wire rope, chains, synthetic fiber lifting slings, steel wire ropes and rigging, cargo lashings, bungee cords, tow ropes, luggage straps and buckles which are listed as illustrative only and not intended to be limiting as to the types of tie downs that may used to practice versions of the invention.
[0035] The attachment means 40 for the external tension member tie downs to the earth anchors may be hooks, carabiners (such as those available at Rapid Response Gear at www.rapidresponse.com, (888) 600-9116, manufactured by Omega Pacific, the modified D'biner, built from certified, aircraft-quality aluminum-alloy bar stock with internally-threaded gate-lock locking mechanisms which mean that the even under load, the locking mechanisms can still be manipulated by hand and eliminates sticking gates, UL Classified, meets and exceeds NFPA 1983 L, ANSI/OSHA strength and construction requirements and standards), hand-tied knots, clamps, friction-type locks and other similar attachment hardware may be used, which are listed as illustrative only and not intended to be limiting as to the types of tie downs that may used to practice versions of the invention.
[0036] To install and use another version of the invention on a structure, as shown in FIG. 3 and FIG. 4 , typically the operator would first install a plurality of earth anchors 41 around the perimeter of the structure in a preconfigured arrangement and locations. Then, for example, the first end of a plurality of external first tension members 10 , are attached to the attachment means 40 on a plurality earth anchor means 41 . The plurality of external tension members 10 are attached to a net means 15 (as shown in FIG. 4 ) which is spread over entire roof surface 30 , the eaves ( 33 and 34 with or without overhang(s)) and roof ridge 31 and over a plurality of eave cushions 20 and ridge cushions 21 (the cushions may be continuously disposed on the entire roof ridge 31 and roof eaves 33 and 34 , with or without overhang(s), as shown in FIG. 5 ) after first positioning the cushions in a preconfigured arrangement and locations under the external net means 15 , and then attached to the other plurality of earth anchor means 41 , also depicted in FIG. 3 , FIG. 4 and FIG. 5 . The at least one means for adjusting 11 (previously integrated into the plurality of tension members 10 ) is tightened sufficiently and the system is ready for use. Or, both tension members in combination with a net may be used as shown in FIG. 4 . Or, solely an external net may be used directly attached to the earth anchor means 41 via the attachment means 40 .
[0037] To uninstall and remove this version of the invention from the structure, if desired, the above-referenced installation procedure is reversed.
[0038] Another embodiment of the invention is depicted in FIG. 7 . This version is made and installed as previously described and may use at least one earth anchor 41 located upwind from the wind force and connected to an external continuous tension member 16 , using the optional bottom tension member 17 under the crawl space 35 . This version may also use an external net means 15 , with or without an external continuous tension member 16 , alone or in combination. A bottom edge protector 22 may also be used in this version as shown in FIG. 7 .
[0039] The above-referenced device and system is not limited to the enumeration of parts or exact details of construction disclosed herein, as these are merely examples and not meant to be limiting. The shape, number and sizes of each external tension member, external net and/or net means, earth anchors, earth anchor means, attachment means and all other components may be varied so as to accommodate specific items and use thereof. The size, shape and materials of construction of the various components can be varied as desired.
[0040] For example many buildings are designed using CAD (computer aided design) software programs, such as AutoCAD, available from Autodesk, Inc., 111 McInnis Parkway, San Rafael, Calif. 94903, USA, Phone: 415-507-5000, Fax: 415-507-5100. The CAD program can be combined with CAM (computer aided manufacturing) such as that available from BobCAD-CAM software, CADCAMDepot.com, 1981 Dunloe Circle, Dunedin, Fla. 34698. Toll Free Phone: 877-880-4488, International: 727-735-0584.
[0041] The CAD-CAM software enables a 3 dimensional (3-D) building/structure roof design to be integrated into the manufacturing process of the roof net or mesh pliable membrane to be used. Thus, the roof net may be manufactured to the precise tolerances and shape of the roof. Thus CAD-CAM enables versions of the invention to be practiced on more complex roof structures that involve several ridges, valleys, eaves, etc. as needed by the operator. Nonlinear, round, curved and any other shape roofs may utilize versions of the invention. It is understood that these CAD-CAM techniques are well known to one skilled in the art and may be used to practice versions of the invention.
[0042] Another embodiment of the invention may be used for aircraft hangars. This embodiment can be used for any aircraft hangar shape, but for illustrative purposes, FIG. 6 depicts an arch-shaped hangar 16 on a foundation 33 . In this application, this version of the device and system may comprise solely an external net 15 , with or without cushions, attached to a plurality of earth anchors, made and installed in a similar manner as the above-referenced roof eave and roof ridge type system. This embodiment may use external tension members and external netting or only use the external netting itself to restrain the structure and attached to the earth anchors. The attachment means 42 may be integrated into the existing concrete foundation 33 , as shown with the external tension member and/or external netting in dotted lines connected to an attachment means 42 in the foundation 33 (also referred to as a footer or footing in the industry). This attachment means could be an eye bolt, U bolt, bent rebar or similar hardware is either installed when the foundation concrete is poured in liquid form prior to hardening or installed after the foundation concrete has hardened by drilling and securing with epoxy glue, expandable anchors, “red eyes” and other type concrete anchors, all well known in the industry.
[0043] The foregoing objects, benefits and advantages of versions of the invention are illustrative of those which can be addressed by versions of the invention and not intended to be limiting or exhaustive of the possible advantages that can be realized. These and other advantages will be apparent from the description herein or can be learned from practicing versions of the invention, both as embodied herein as examples or as modified in view of any variations which may be apparent to those of ordinary skill in the art. Therefore, the invention resides in the novel devices, methods, arrangements, systems, combinations and improvements herein shown and described as examples and not limited therein.
[0044] It is also understood that whenever and/or is used in this patent application it means any combination or permutation of all, one, some, a plurality or none of each of the item or list mentioned, which is not intended to be limiting but merely for example and illustration. It is also understood that (s) designates either singular or plural. It is also understood that that “or” is an inclusive “or” to include all items in a list and not intended to be limiting and means any combination or permutation of all, one, some, a plurality or none of each of the item or list mentioned. It is also understood that “including” means “including but not limited to” any combination or permutation of all, one, some, a plurality or none of each of the item or list mentioned.
[0045] As will be apparent to persons skilled in the art, such as an architect, engineer, designer, fabricator, net designer and other similar artisans skilled in the art, various modifications and adaptations of the structure and method of use above-described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the claims. Although the foregoing invention has been described in detail by way of illustration and example, it will be understood that the present invention is not limited to the particular description and specific embodiments described but may comprise any combination of the above elements and variations thereof, many of which will be obvious to those skilled in the art. Additionally, the acts and actions of fabricating, assembling, using, and maintaining the preferred embodiment of this invention is well known by those skilled in the art. Instead, the invention is limited and defined solely by the following claims.
[0046] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Appendix A
3 pages after this page, 16A, 16B and 16C
[0047]
[0000]
Approved Tie Down Assemblies
Number
Manufacturer
Product
1086 B-A
EPCO Mobile Home Products
EPCO Ground Hog Mobile Home Anchors
1308 S. Kalamazoo Avenue
Models: RH61-6, RH-51-6, DRH51-6, DRH61-6
Marshall, MI 49068
1087 B-A
Stromberg Carlson Products
“Huggor” Mobile Home Tie Down
PO Box 164
Models: 48/S, 48/D, T4-36S, T4-36D
226 E. 16th Street
Traverse City, MI 49684
1088 B-A
Transtationary Foundation
Transtationary Foundation Systems
Systems
20131 James Couzens Highway
Detroit, MI 48235
1102 B-A
Barker Manufacturing Company
MH Pier/Tie Down Device
730 E. Michigan Avenue
Models: MHAP-12, MHAP-13, MHAP-14, MHAP-15, and
Battle Creek, MI 49016
MHAP-16
1107 B-A
Imperial Stamping Co., Inc.
MHA Corporation Home Anchors and Accessories
23852 Reedy Drive
Models: MHA-SB-2, MHA-SB-3, MHA-SB-4, MHA-SB-6, MHA-
Elkhart, IN 46514.
SB-7, MHA-SB-8, MHA-MHA-SB-10, MHA-SB-12, MHA-SB-15-
36, MHA-SB-15-48, MHA-SB-16, MHA-SB-17, MHA-SB-20,
MHA-SB-21, MHA-SB-22, MHA_SB-26, MHA-SB-46, MHA-SB,
MHA-2, MHA-4, MHA-6, MHA-8, MHA-10, MHA-12, MHA-14,
MHA-16, MHA-20, MHA-21, MHA-22, MHA-24, MHA-26, MHA-
33, MHA-39, MHA-40, MHA-56, and MHA-58
Doc. 92-071
1189 B-MH
Anchor Sur
Mobile Home Anchoring System
Div. of Poly Foan Int'l.
1218 Lime Street
PO Box 684
Fremont, OH 43420
1196 B-MH
Barker Manufacturing Co.
Stable Safe MH Tie Down
730 E. Michigan Avenue
PO Box 460
Battle Creek, MI 49016
1198 B-MH
American Skirting Co.
The Crabline Tie Down Assembly
6560 Bethuy Road
Anchorville, MI 48004
B-94-637
Tie Down Engineering, Inc.
Mobile home anchors.
5901 Wheaton Drive
Models: MI 2H, MI 2H6, MI 22, MRA, MRAX 48, and related
Atlanta, GA 30336
accessories.
PA-96-004
Home Pride, Inc.
Mobile home anchors:
2976 Lee Highway, Unit 2
Models: HP-1, HP-3, HP-4, HP-10, HP-12, HP-13, HP-14,
Bristol, VA 24201
HP-17, HP-30.
Doc. 96-32
The anchoring system consists of steel disk anchors, steel
concrete anchors, expansion bolts, strapping, and related
accessories.
PA-96-001
Minute Man Anchors, Inc.
Manufactured housing tiedowns:
305 West King Street
Models: 650-DH 5/8, 4636-DH 3/4, 36X-DH, THDH,
East Flat Rock, NC 28726
650-DH 3/4, 4430-DH 5/8, 48X-DH, THDHLS, 650-DH 11/16,
4430-DH 11/16, 36-DH, FCI W/S, 636-DH 5/8, 4430-DH 3/4,
210-DH, FCII W/S, 636-DH 3/4, 4450-DH 5/8, 210-PDH, BUC
W/S, 672-DH 3/4, 4450-DH 11/16, 210-JDH, SBNB, 860-DH
3/4, 4450-DH 3/4, 100-DH, MMASD2 MMA STRAP.
Doc. 96-33
The anchoring system consists of earth auger anchors,
strapping, cross drives, buckles, and related accessories.
PA-94-001
Hydroflo Systems, Inc.
Earth Anchor:
3729 Linden, S. E.
Developed to stabilize the inward bow or deflection of
Wyoming, MI 49548
masonry block or concrete walls caused by lateral earth
pressure resulting from backfill against the wall.
PA-97-001
GOP Industry
Mobile Home Anchor:
19266 Berden
Four-hole chain connector link used as an extension in their
Harper Woods, MI 48225
patented Crab Line Tie Downs for mobile home installations.
PA-99-001
Frenchy's Skirting, Inc.
Manufactured Housing Tie-Down:
34111 Michigan Avenue
Model: 031933
Wayne, MI 48184
Provides anchorage to withstand wind forces and uplift.
PA-99-003
Tie Down Engineering Inc.
Foundation/Anchoring System
5901 Wheaton Drive
Model: Dirt System #59007
Atlanta, GA 30336
Concrete System #59008
Vector Dynamics - Doundation/Anchoring System
Provides foundation/achoring system for manufactured
housing and modular buildings to resist wind loads as
designated by HUD Code (MHCSS 3280 306).
1474-BA
Tie Down Engineering, Inc.
ABS FOUNDATION PADS:
5901 Wheaton Drive
Part #59300 - 2 sq. ft.
Atlanta, GA 30336
Part #59301 - 2.5 sq. ft.
(404) 344-0000
Part #59302 - 3 sq. ft.
Submission PA-00-0001
BEAM CLAMPS:
Part #59002 - Swivel Strap Connector
Part #59003 - 3″ Swivel Strap Frame Connector (beam clamp)
Part #59004 - 4″ Swvel Strap Frame Connector (beam clamp)
Part #59005 - Adjustable Swivel Strap Frame Connector
(clamp)
Part #59011 - Flange Beam Clamp
Part #59009 - Longitudinal Beam Clamp
STABILIZER PLATE:
Part #59291
1488-BA
Benchmark Resources, Inc.
Benchmark Insulated Concrete Wall System
70 S. Grey Road
The Benchmark Insulated Concrete Wall System is an
Auburn Hills, MI 48326
extruded polystyrene form with cold-formed stell channel and
Submission PA-00-0002
steel bar reinforced concrete wall system to be used both
below grade and above grade residential and light commercial
applications.
1489-BA
Tie Down Engineering, Inc.
Vector Dynamics - Foundation/Anchoring System for
5901 Wheaton Drive
manufactured housing and modular buildings to resist wind
Atlanta, GA 30336
loads as designated by HUD Code (MHCSS 3280 306).
(404) 344-0000
Amend Product Approval No. 1464-BA to add 18 inch round
Submission PA-00-0003
foundation pier option.
1490-BA
Tie Down Engineering, Inc.
Part No. 59013 - Tube
5901 Wheaton Drive
Part No. 59272 - Longitudinal Beam Clamp
Atlanta, GA 30336
Part No. 59282 - Longitudinal Link
(404) 344-0000
Part No. 59310 - Foundation Pad
Submission PA-00-
Part No. 59277 - Foundation Pad (Concrete)
Part No. 59373 - Foundation Pad (Concrete) | An device, system and method of using is disclosed to provide a releasably attached external tension member(s), earth anchor(s), net(s), means for adjusting and means for attaching to the earth anchor(s) to accomplish an emergency structure restraint system. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a shielding terminal to be connected with an end of a shielded cable and to a method for mounting a shielding terminal to an end of a shielded cable.
[0003] 2. Description of the Related Art
[0004] A known shielding terminal is illustrated in FIGS. 8 and 9 and has an inner terminal “a” for connection with a mating terminal, an outer terminal “c” that accommodates the inner terminal “a” and a dielectric element “b” provided between the inner and outer terminals “a” and “c”. The inner terminal “a” is crimped into connection with an end of a core “e” of a shielded cable “d”, and the outer terminal “c”” is crimped into connection with ends of a braided wire “f” and a sheath “g”.
[0005] A shielding terminal of the type shown in FIGS. 8 and 9 must have a large fastening force to the shielded cable “d” to prevent the shielded cable “d” from being detached from the shielding terminal in response to a pulling force on the shielded cable “d”. Conventionally, biting blades have been formed to project from the outer surface of the inner terminal “a”. The biting blades bite in the inner surface of the dielectric element “b” to prevent the shielded cable “d” from being detached from the shielding terminal.
[0006] The conventional shielding terminal has a groove formed behind the biting blades in the inner surface of the dielectric element. Thus, sufficient force to prevent the detachment may not be obtained due to a possible insufficient degree of engagement. Accordingly, there is a demand for a further improvement.
[0007] The present invention was developed in view of the above situation and an object thereof is to provide a shielding terminal and a mounting method that achieve a larger fastening force of the shielding terminal to a shielded cable.
SUMMARY OF THE INVENTION
[0008] The invention is directed to a shielding terminal that can be connected with an end of a shielded cable. The shielding terminal comprises an inner terminal for connection with a core of the shielded cable and an outer terminal for connection with a shield layer of the shielded cable. The outer terminal at least partly accommodates the inner terminal with a dielectric element provided between the inner and outer terminals. The shielding terminal further comprises a lock mountable in or on the outer terminal for preventing the inner terminal from coming out.
[0009] A force may act to move the inner terminal out of the dielectric element, such as when the core is pulled. However, the inner terminal is locked in the outer terminal by the lock and is prevented from coming out of the dielectric element. Therefore, a fastening force to the shielded cable can be strengthened.
[0010] A preferred embodiment of the shielding terminal is constructed for connection with an end of a shielded cable that comprises a core, an insulating layer surrounding the core, a braided wire surrounding the insulating layer and a sheath on the outer surface of the braided wire. The shielding terminal comprises an inner terminal to be connected with the core and an outer terminal to be connected with the braided wire. The outer terminal accommodates the inner terminal and a dielectric element that is provided between the inner and outer terminals. A lock is mounted in the outer terminal to prevent the inner terminal from coming out of the outer terminal. More particularly, an opening may be formed in part of a circumferential surface of the outer terminal, and the lock may be mounted at least partly in the opening. The lock mounted in the opening in the circumferential surface of the outer terminal prevents the shielding terminal from becoming larger.
[0011] A shield plate may be mounted on or provided in the lock. The shield plate preferably is connectable with the shield layer and/or the outer terminal. A shielding performance can be improved by providing the shield plate in the opening where no shield member has been present.
[0012] The lock preferably is formed with a locking edge that can be locked with a rear portion of the inner terminal, and preferably with a connection portion of the inner terminal.
[0013] The lock preferably comprises latching means for latching the lock with the inner and/or outer terminals. The latching means may comprise hooks that engage at least one crimping portion of the outer terminal.
[0014] The lock may comprise locking means for engagement with a sheath of the shielded cable and/or with the dielectric member.
[0015] The invention also is directed to a method for mounting, assembling or connecting a shielding terminal with an end of a shield cable. The method comprises connecting an inner terminal with a core of the shielded cable. The method then comprises connecting an outer terminal with a shield layer of the shielded cable and at least partly accommodating the inner terminal with a dielectric element provided between the inner and outer terminals. The method then includes mounting a lock in or on the outer terminal for preventing the inner terminal from coming out.
[0016] The lock preferably is mounted in an opening formed in part of a circumferential surface of the outer terminal.
[0017] Preferably, a shield plate is mounted on or in the lock. The shield plate preferably is connected with the shield layer and/or the outer terminal.
[0018] These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is an exploded perspective view of one embodiment of the present invention.
[0020] [0020]FIG. 2 is an exploded side view partly in section of this embodiment.
[0021] [0021]FIG. 3 is a front view of a lock member.
[0022] [0022]FIG. 3A is front view of an alternative to the lock shown in FIG. 3.
[0023] [0023]FIG. 3B is a cross sectional view taken a long line 3 B- 3 B in FIG. 3A.
[0024] [0024]FIG. 4 is a vertical section showing a mounting operation of the locking member.
[0025] [0025]FIG. 5 is a vertical section showing an assembled state of a shielding terminal and a shielded cable.
[0026] [0026]FIG. 6 is a rear view showing the assembled state.
[0027] [0027]FIG. 7 is a bottom view showing the assembled state.
[0028] [0028]FIGS. 8 and 9 are a perspective view and a plan view of a prior art shielding terminal connected with a shielded cable.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] A female shielding terminal in accordance with the invention is identified by the numeral 10 in FIGS. 1 - 7 . The female shielding terminal 10 can be crimped, folded or bent into connection with an end of a shielded cable 1 . The shielded cable 1 has a known structure with a core 2 formed by bundling a plurality of strands. An insulating layer 3 surrounds the core 2 , and a shield layer, such as a braided wire 4 or a shield film surrounds the insulating layer 3 . A sheath 5 made of a rubber or the like surrounds the braided wire 4 , as shown in FIGS. 1 and 2. An end of the shielded cable 1 is processed by stripping off an end of the sheath 5 . The exposed section of the braided wire 4 then is folded back on the sheath 5 , and an exposed end of the insulating layer 3 is cut off to expose the core 2 .
[0030] The shielding terminal 10 is comprised of an inner terminal 11 , an outer terminal 12 , a dielectric element 13 and a locking member 14 , as shown in FIGS. 1 and 2.
[0031] The inner terminal 11 is formed by bending a metallic plate, and includes opposite front and rear ends. A substantially rectangular tubular female connecting portion 15 is formed at the front end, and transversely arranged inner crimping pieces 16 are formed behind the connecting portion 15 for crimped connection with the core 2 of the shielded cable 1 . Contact pieces 17 are formed at opposite side surfaces of the connecting portion 15 , and are configured for connection with a tab (not shown) of a mating male inner terminal. The contact pieces 17 cantilever forward and are bent so that facing surfaces at the leading ends of the contact pieces 17 bulge inwardly. The contact pieces 17 are resiliently or elastically deformable in directions that cause their leading ends to move toward and away from each other as the tab of the mating terminal is insertable therebetween.
[0032] The bottom wall of the rear end of the connecting portion 15 is cut off, and one or more biting blades 18 are formed at the bottom edges of the left and right side walls near the rear end. The biting blades 18 bite in the bottom wall of the dielectric element 13 when the connecting portion 15 is pressed into the dielectric element.
[0033] The outer terminal 12 also is formed by bending a metallic plate and has opposite front and rear ends. A large substantially rectangular tubular accommodating portion 20 is formed at the front end of the outer terminal 12 , and a covering wall 21 is formed rearward of the accommodating portion 20 . The covering wall 21 is closed on three sides, but has an open bottom. An outer crimping portion 23 is formed to the rear of the covering wall 21 and can be crimped, folded or bent into connection with a folded section of the braided wire 4 of the shielded cable 1 . The outer crimping portion 23 has two transversely arranged outer crimping pieces 24 that are wound or folded at least partly around the folded section of the braided wire 4 such that an end of one crimping piece 24 is placed substantially over the end of the other. The crimped outer crimping portions 23 have an arcuate upper surface with a small curvature, a substantially semicircular bottom surface, and substantially parallel left and right surfaces.
[0034] Wedge-shaped projections 25 are formed at the base ends of the two outer crimping pieces 24 and on the outer crimping piece 24 which is placed more inside the other in its wound state. Further, stabilizers 26 project laterally outward from the bottom edges of the left and right side walls of the covering wall 21 .
[0035] The dielectric element 13 is made of an insulating material, such as a synthetic resin, and electrically insulates the inner and outer terminals 11 , 12 from each other. The dielectric element 13 has a shape that conforms to the inner and outer terminals 11 , 12 and preferably is in the form of a substantially rectangular tube with a thick wall that can be fit into the front end of the accommodating portion 20 of the outer terminal 12 . An accommodating hole 28 is defined inside the dielectric element 13 , and is dimensioned to accommodate the connecting portion 15 of the inner terminal 11 . A flange 29 is formed at the front surface of the dielectric element 13 and can be brought into abutment against the front edge of the accommodating portion 20 of the outer terminal 12 . A terminal insertion opening 30 is defined at the front end of the accommodating hole 28 for receiving the tab of the mating terminal. Further, the lower half of the rear end of the dielectric element 13 is cut off to conform to the configuration of the accommodating portion 20 of the outer terminal 12 .
[0036] A metal lock 32 is formed by cutting the upper surface of the accommodating portion 20 of the outer terminal 12 and bending the cut portion inward and obliquely backward. Additionally, a lock hole 33 is formed in the upper surface of the dielectric element 13 for receiving the metal lock 32 of the outer terminal 12 .
[0037] The lock 14 is made e.g. of a synthetic resin and is mounted in an area that extends substantially from an opening 22 of the covering wall 21 of the outer terminal 12 to the outer crimping portion 23 . The lock 14 includes a narrow base plate 40 and has a front portion that is sufficiently narrow to be fit closely into the opening 22 of the covering wall 21 (see FIG. 7). Two mounting plates 41 project substantially normal to the opposite side edges of the rear end of the base plate 40 . The mounting plates 41 are formed to surround the crimped outer crimping portion 23 from its bottom surface to its left and right side surfaces. Hooks 42 extend inward at the upper ends of the mounting plates 41 and engage the left and right corners of the upper surface of the crimped outer crimping portion 23 . The mounting plates 41 are resiliently or elastically deformable such that their upper ends move toward and away from each other.
[0038] The base plate 40 is thicker at the front end than at the rear end, and a locking step 44 is defined at the rear of the upper surface of the front end. The locking step 44 engages the end of the sheath 5 of the shielded cable 1 that is covered by the folded section of the braided wire 4 and engages the front part of the crimped outer crimping portion 23 .
[0039] A front half of the front end of the base plate 40 is thinned in the widthwise center of its lower surface to form a gate. The upper edge of the front surface of this gate defines a locking edge 45 that is engageable with the bottom of the rear end of the connecting portion 15 of the inner terminal 11 . Further, left and right side edges 46 of the front surface of the gate engage edges left by cutting off the portions of the dielectric element 13 and the accommodating portion 20 of the outer terminal 12 , as shown in FIG. 5.
[0040] Left and right side walls 48 stand from the left and right side edges of the front end of the base plate 40 , and a portion of an assembly of the inner terminal 11 and the shielded cable 1 from the end of the insulating layer 3 to the inner crimping pieces 16 can be accommodated between the side walls 48 .
[0041] The end of the shielded cable 1 is processed as described above, and the inner crimping pieces 16 of the inner terminal 11 are crimped, folded or bent into connection with the end of the core 2 . The dielectric element 13 then is inserted into the accommodating portion 20 of the outer terminal 12 from the front. The insertion of the dielectric element 13 deforms the metal lock 32 . However, the metal lock 32 is restored resiliently toward its original shape to fit into the locking hole 33 when the flange 29 contacts the front edge of the accommodating portion 20 , as shown in FIG. 4. As a result, the dielectric element 13 is fixed at the front end of the accommodating portion 20 .
[0042] Subsequently, the inner terminal 11 is inserted into the accommodating portion 20 of the outer terminal 12 from behind, and is pushed into the accommodating hole 28 of the dielectric element 13 that is fixed in the accommodating portion 20 . More particularly, the inner terminal 11 is pushed by a jig inserted through the opening 22 of the covering wall 21 . At this stage, the biting blades 18 press against and bite into the bottom wall of the accommodating hole 28 . As a result, the inner terminal 11 is partly locked.
[0043] The outer crimping pieces 24 of the outer terminal 12 then are crimped and wound at least partly around the folded section of the braided wire 4 for fastened to the folded section of the braided wire 4 and the end of the sheath 5 . At this time, the projections 25 bite into the braided wire 4 to achieve a stronger fastening of the outer crimping pieces 24 .
[0044] Finally, as indicated by the arrow in FIG. 4, the lock 14 is mounted in the area extending from the opening 22 of the covering wall 21 of the outer terminal 12 to the outer crimping portion 23 . More particularly, the opposite side walls 48 on the base plate 40 are inserted into the opening 22 of the covering wall 21 . Simultaneously, the opposite mounting plates 41 move along the crimped outer crimping portion 23 and widen the spacing between the opposed mounting plates 41 . When the side walls 48 are inserted sufficiently to contact the ceiling surface of the accommodating portion 20 of the outer terminal 12 , the hooks 42 of the mounting plates 41 pass the corners of the upper surface of the outer crimping portion 23 . Thus, the hooks 42 engage the corners of the upper surface of the outer crimping portion 23 and the mounting plates 41 are restored as shown in FIG. 6. Preferably simultaneously, the locking step 44 engages the end of the sheath 5 and the front part of the outer crimping portion 23 ; the rear edges of the side walls 48 engage the front end of the sheath 5 ; the left and right side edges 46 at the front surface of the gate engage the cut-off portions of the dielectric element 13 and the outer terminal 12 from behind; and the front ends of the side walls 48 engaged the rear end of the upper part of the dielectric element 13 .
[0045] In this way, the lock 14 is fixed in the outer terminal 12 and will not move downward, forward or backward. Additionally, the lock 14 covers the opening 22 of the covering wall portion 21 of the outer terminal 12 and the outer crimping portion 23 .
[0046] At this time, the locking edge 45 at the leading end of the lock 14 faces and lockingly engages the bottom end of the rear end of the connecting portion 15 of the inner terminal 11 . Thus, a pulling force on the core 2 of the shielded cable 1 is resisted by the engagement of the rear end of the connecting portion 15 with the locking edge 45 of the lock 14 to prevent the inner terminal 11 from coming out of the dielectric element 13 .
[0047] As described above, a “double-locking construction” is realized by providing the lock 14 for locking the inner terminal 11 in the outer terminal 12 . This effectively prevents the inner terminal 11 from coming out of the dielectric element 13 and strengthens a fastening force to the shielded cable 1 .
[0048] Further, the lock 14 is mounted mainly by being fitted in the opening 22 of the covering wall 21 . Thus, the lock 14 prevents the entire shielding terminal 10 from becoming larger despite the provision of the lock 14 , as shown in FIGS. 3A and 3B.
[0049] The shielding performance of the terminal 10 can be improved by incorporating at least one shield into the lock 14 . The shield may be disposed at portions of the lock 14 that will engage the shield layer 4 of the shielded cable 1 and/or the outer terminal 12 . For example, a metal coating 47 can be applied to lower surface regions of the base plate 40 , outer surface regions of the mounting plates 41 and upper and outer surface regions of the hooks 42 . Thus, a continuous shielding will extend across the open bottom of the covering wall 21 and substantially continuously between the accommodating portion 20 and the crimping pieces 24 . Alternatively, a separate metal plate (not shown) can be insert molded into the lower portions of the lock 14 for extending across the open bottom of the covering wall 21 .
[0050] The present invention is not limited to the above described and illustrated embodiments. For example, following embodiments are also embraced by the technical scope of the present invention as defined in the claims. Beside the following embodiments, various changes can be made without departing from the scope and spirit of the present invention as defined in the claims.
[0051] If a metallic plate is mounted as a shield plate in the locking member and part thereof is electrically connected with the outer terminal or another shield wall, the shield plate can also be provided at the opening of the covering wall portion where no shield member has been present. As a result, shielding performance can be improved.
[0052] Although the female shielding terminal is illustrated in the foregoing embodiment, the present invention is similarly applicable to male shielding terminals. | A shielding terminal has a lock ( 14 ) mounted in an area extending from an opening ( 22 ) of a covering wall ( 21 ) to an outer crimping portion ( 23 ) of an outer terminal ( 12 ), and is fixed with respect to the outer terminal ( 12 ) by mounting plates ( 41 ) wrapping around the outer crimping portion ( 23 ). At this stage, a locking edge ( 45 ) at the leading end of the lock ( 14 ) faces a bottom end of the rear end of a connecting portion ( 15 ) of an inner terminal ( 11 ) so as to be engageable therewith for locking. Accordingly, even if the inner terminal ( 11 ) tries to come out of a dielectric element ( 13 ) upon action of a pulling force on a core ( 2 ) of a shielded cable ( 1 ), the rear end of the connecting portion ( 15 ) comes into contact with the locking edge ( 45 ) of the lock ( 14 ) to prevent such a movement. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a flame retardant composition and the like, and particularly to a halogen-free flame retardant composition containing no antimony, phosphorus and phosphorus compounds at all, a halogen-free flame-retardant resin composition of environmental flameproof type made of the flame retardant composition, which is slow in spreading fire during incipient fire and causes little carbon monoxide (CO) during combustion while having high flame retardance, and molded products, electric wires, cables, fiber or fiber post-processed products made of the resin composition.
[0003] 2. Description of the Related Art
[0004] Resin using halogen compounds and antimony compounds together has widely been used for conventional flame-retardant materials. However, in recent years, with regard to halogen flame-retardant materials, the influence on the environment is regarded as a problem and the use thereof tends to be prohibited or restricted due to regulation in Europe; therefore, the development of halogen-free flame-retardant materials is in progress in each company.
[0005] Phosphorus-containing compounds are principally considered as halogen-free flame-retardant materials, and phosphorus flame retardants such as red phosphorus and phosphate are used; but yet the occurrence of phosphine gas during the use of red phosphorus is pointed out, and the problem is bleed-out during molding with regard to phosphate.
[0006] Thus, a halogen-free flame-retardant resin composition using magnesium hydroxide is proposed for the purpose of preventing secondary disasters such as fuming, toxicity and corrosion during combustion as described in Japanese Unexamined Patent Publication No. 01-141929, for example.
SUMMARY OF THE INVENTION
[0007] Generally, flame resisting is surmised as incomplete combustion, and flame resisting mechanism brings a possibility of causing oxygen (O 2 ) concentration to be diluted due to emission of harmful gas in large quantities. Flameproofing of plastics is important for causing no fires, while carbon monoxide poisoning and oxygen deficiency frequently take a precious life in the case of considering a real fire. Thus, the development of flame-retardant materials has been demanded, such as to cause as little carbon monoxide during combustion as possible.
[0008] However, due to incomplete combustion of materials as flame resisting mechanism, conventional flame-retardant plastics result in O 2 dilution due to the occurrence of gas in large quantities and the occurrence of harmful CO, and are accompanied by the occurrence of fuming and soot in large quantities. That is to say, while flameproofing is performed, CO as a problem after fire breaking tends to increase, and it is pointed out that the increase of CO is a problem in view of disaster prevention; therefore, materials are expected which have high flame retardance and decrease the occurrence of fuming, CO and soot after combustion is caused. Also, soot is a direct problem such as harmful inhalation and closed our sight during fire breaking, and additionally it is reportedly pointed out that soot is a factor of global warming. Here, high flame retardance signifies UL94 Test V0 ( 1/32″).
[0009] The Building Standard Law of Japan prescribes that heating for 5 minutes be the condition, and in fact it is extremely important that the maximum combustion be not caused within 5 minutes; for example, arrival time of the maximum smoke concentration and the maximum heat generation rate is not less than 5 minutes, which leads to the delay of O 2 dilution. Accordingly, the realization of flame-retardant materials in which CO occurrence is little and fuming is restrained is also conceived to be the advent of an epoch-making technique.
[0010] The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a halogen-free flame retardant composition containing no antimony, phosphorus and phosphorus compounds at all, a halogen-free flame-retardant resin composition of environmental type ideal for disaster prevention made of the flame retardant composition, which causes little carbon monoxide (CO) during combustion while having high flame retardance, and molded products, electric wires, cables, fiber or fiber post-processed products made of the resin composition.
[0011] In order to achieve the above-mentioned object, the inventors of the present invention have made earnest studies, and as a result, found that a mixture of a specific resin having an average particle diameter of not more than 1000 μm and metal hydrate brings high flame retardance and allows harmful carbon monoxide to be restrained from occurring. The present invention has been completed.
[0012] That is, the present invention provides a flame retardant composition comprising a mixture of (A) a resin having an average particle diameter of not more than 1000 μm selected from wholly aromatic polyamide, polyimide, polyamideimide, a copolymer of the wholly aromatic polyamide, the polyimide or the polyamideimide or a mixture of the above mentioned polymers and (B) a metal hydrate.
[0013] Also, the present invention provides a flame-retardant resin composition containing the above-mentioned flame retardant composition in an amount of 50 to 200 parts by mass with respect to 100 parts by mass of a thermoplastic resin or a thermosetting resin.
[0014] Also, the present invention provides molded products, electric wires, cables, fiber or fiber post-processed products made of the above-mentioned flame-retardant resin composition.
[0015] The present invention can provide a flame-retardant resin composition which is flame-retardant, high in an LOI value and slight in the occurrence amount of harmful CO. In addition, molded products to be obtained have no anisotropy and favorable appearance.
[0016] The use of a specific resin having an average particle diameter of not more than 1000 μm together with metal hydrate develops high synergistic effect, which has not been capable of being produced in each single system. Therefore, products of environmental type ideal for disaster prevention, which are halogen-free flame-retardant materials, are slow in spreading fire during incipient fire and restrain CO from occurring while having high flame retardance, can particularly be realized in the case of being made into molded products, electric wires, cables and fiber.
[0017] A flame retardant composition, a flame-retardant resin composition, molded products, electric wires, cables, fiber or fiber post-processed products of the present invention are conceived to be halogen-free flame-retardant materials of real environmental type, which are free from environmental burden such as phosphoric acid elution during use and abandonment, by reason of containing no phosphorus at all to bring no fear that phosphoric acid is eluted by water under the use environment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Resin having an average particle diameter of not more than 1000 μm as an (A) component used in the present invention forms a char layer on the surface of molded products and has the function of restraining spreading fire and fuming during incipient fire. The resin is at least one kind selected from wholly aromatic polyamide, polyimide, polyamideimide, a copolymer thereof or a mixture thereof; these resins may be used singly or in proper combination of not less than two kinds. When the average particle diameter of the above-mentioned resin exceeds 1000 μm, a resin in a flame retardant composition is not melted at molding temperature of a thermoplastic resin in the case of blending the flame retardant composition with the thermoplastic resin, so that resin pellets can not be produced. The average particle diameter of the resin in a flame retardant composition is preferably not more than 800 μm, more preferably not more than 300 μm.
[0019] These resin particles can also be obtained by pulverizing films, sheets and molded products made of the above-mentioned resin. Pulverizing means and pulverizing methods are not particularly limited but known methods can be performed.
[0020] Here, a wholly aromatic polyamide is such that at least not less than 85 mol %, preferably 100 mol %, of amide bonds are obtained from an aromatic diamine component and an aromatic dicarboxylic acid component. Specific examples thereof include wholly aromatic polyamides such as polyparaphenylene terephthalamide, polymetaphenylene terephthalamide, polymetaphenylene isophthalamide and polyparaphenylene isophthalamide; aromatic polyamides in which aromatic diamine is bonded by groups such as ether group and contains two phenyl groups, such as 3,3′-oxydiphenylene diamine and 3,4′-oxydiphenylene diamine; or copolymers of the above-mentioned aromatic polyamides, such as a poly-3,3′-oxydiphenylene terephthalamide/polyparaphenylene terephthalamide copolymer and a poly-3,4′-oxydiphenylene terephthalamide/polyparaphenylene terephthalamide copolymer.
[0021] A polyimide is a resin produced by condensation polymerization of aromatic tetracarboxylic dianhydride and diamine, or the like, and is excellent in heat resistance, chemical resistance and electrical insulating properties. The polyimide may be either a thermosetting polyimide or a thermoplastic polyimide, and yet a thermoplastic polyimide is preferable in term of formation of a char layer stable in molding.
[0022] A polyamideimide is a resin produced by reaction of trimellitic anhydride and diisocyanate, or trimellitic chloride anhydride and diamine, and is so excellent in heat resistance as to be capable of being subjected to thermoforming, and is excellent in chemical resistance and electrical insulating properties.
[0023] The metal hydrate as a (B) component has the function of allowing flame retardance and tracking resistance. Examples of metal hydrate include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, and the like. These metal hydrates can be used in the shape of powdery and granular material, flake or fiber. Among them, magnesium hydroxide or aluminum hydroxide is preferable and aluminum hydroxide is particularly preferable. The metal hydrates may be used singly or in proper combination of not less than two kinds.
[0024] In the present invention, it is important to blend a mixture of a specific resin having an average particle diameter of not more than 1000 μm as the (A) component and (B) metal hydrate, and in the case of blending either of them singly, flame retardance is insufficiently improved and the maintenance of shrink resistance is not intended. The mass ratio of the (A) component/the (B) component is preferably 1/99 to 80/20, more preferably 2/98 to 50/50. When the ratio of the (A) component is less than 1, flame retardance is deteriorated and the occurrence amount of CO during combustion is increased. On the other hand, when the ratio of the (A) component exceeds 80, moldability during blending a resin is deteriorated.
[0025] In a flame retardant composition of the present invention, plasticizer, pigment, filler, foaming agent, crystalline nucleating agent, lubricant, processing aid, antistatic agent, antioxidant, ultraviolet absorbing agent, heat stabilizer and surface-active agent can be blended as required in addition to the above-mentioned (A) and (B) components in a range of not deteriorating the object of the present invention.
[0026] Examples of the thermoplastic resin to be used in the present invention include polyolefins such as polyethylene, polypropylene and polybutylene; methacrylates such as polymethyl methacrylate; polystyrenes such as polystyrene, ABS resin and AS resin; polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate, polyethylene naphthalate (PEN) and poly-1,4-cyclohexyldimethylene terephthalate (PCT); polyamides selected from nylons and nylon copolymers such as polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polydodecaneamide (nylon 12), polyhexamethylene terephthalamide (nylon 6T), polyhexamethylene isophthalamide (nylon 6I), polycaproamide/polyhexamethylene terephthalamide copolymer (nylon 6/6T), polyhexamethylene adipamide/polyhexamethylene terephthalamide copolymer (nylon 66/6T) and polyhexamethylene adipamide/polyhexamethylene isophthalamide copolymer (nylon 66/6I); polyvinyl chlorides; polyoxymethylenes (POM); polycarbonates (PC); polyphenylene sulfides (PPS); modified polyphenylene ethers (PPE); polyetherimides (PEI); polysulfones (PSF); polyethersulfones (PES); polyketones; polyether nitriles (PEN); polyether ketones (PEK); polyether ether ketones (PEEK); polyether ketone ketones (PEKK); polyimides (PI); polyamideimides (PAI); fluororesins; modified resins such that these resins are modified, or mixtures of these resins with each other or other resins.
[0027] Examples of the thermosetting resin include phenols, epoxy resins, epoxy acrylates, polyesters (such as unsaturated polyesters), polyurethanes, diallyl phthalates, silicone resins, vinyl esters, melamines, polyimides, polybismaleimide triazine resins (BT resins), cyanates (such as cyanate esters), copolymers thereof, modified resins such that these resins are modified, or mixtures of these resins with each other or other resins.
[0028] With regard to the blending ratio of a flame retardant composition to a thermoplastic resin or thermosetting resin, a flame retardant composition is preferably contained in an amount of 50 to 200 parts by mass, more preferably 60 to 150 parts by mass, with respect to 100 parts by mass of a thermoplastic resin or thermosetting resin. The content of the flame retardant composition of not less than 50 parts by mass allows high flame retardance, while the content of not more than 200 parts by mass does not cause flowability necessary for molding to be lost. With regard to the resin composition containing a flame retardant composition of the present invention by the above-mentioned amount, carbon monoxide (CO) concentration in the whole combustion gas by a cone calorimeter in conformity to ISO 5660 becomes not more than 0.01 (g/kg).
[0029] In a flame-retardant resin composition of the present invention, plasticizer, pigment, filler, foaming agent, crystalline nucleating agent, lubricant, processing aid, antistatic agent, antioxidant, ultraviolet absorbing agent, heat stabilizer and surface-active agent can be blended as required in addition to the above-mentioned flame retardant composition and thermoplastic or thermosetting resin in a range of not deteriorating the object of the present invention. Also, reinforced fibers such as aramid fiber, glass fiber, carbon fiber, ceramic fiber and fluorine fiber, and fillers such as silica, talc, clay, alumina, mica and vermiculite may be blended unless the object of the present invention is deteriorated.
[0030] A flame retardant composition of the present invention can be obtained by dry-blending the above-mentioned resin having an average particle diameter of not more than 1000 μm and metal hydrate.
[0031] With regard to a flame-retardant resin composition, shapes of pellet, chopped strand or granule, and a minor axis of 0.1 to 5 mm and a major axis of 0.3 to 10 mm are appropriate for injection molding, extrusion molding, blow molding and film molding. Alternatively, masterbatch in which a flame retardant composition of the present invention is incorporated into a resin at high concentration can also be produced.
[0032] A flame-retardant resin composition of the present invention is subject to various kinds of molding such as injection molding, extrusion molding, blow molding, film molding, press molding and pultrusion, to which composition secondary fabrication is further added as required to obtain molded products, electric wires and cables. The above-mentioned addition agents such as plasticizer is blended as required with the molded products, to which desirable properties are also allowed.
[0033] Alternatively, a flame-retardant resin composition of the present invention is subject to various kinds of spinning steps such as melt spinning and liquid crystal spinning, to which composition secondary fabrication is further added as required to obtain fiber, and additionally desired post-processing is performed therefor as required to allow fiber post-processed products.
[0034] Molded products, electric wires, cables, fiber or fiber post-processed products made of a flame-retardant resin composition of the present invention can be used for all applications in which high flame retardance and electrical characteristics are requested, and are appropriately utilized for insulating materials for electricity.
[0035] Molded products, fiber or fiber post-processed products made of a flame-retardant resin composition of the present invention are appropriately utilized also for, beginning with electric wires and cables, electrical and electronic parts such as connector, plug, arm, socket, cap, rotor and motor parts, machine components such as a plate, bearing, gear, cam, pipe and barstock, AV and OA equipment parts such as a speaker cone, bush, washer, guide, pulley, facing, insulator, rod, bearing cage, cabinet, bearing, rod, guide, gear, parts and members for building, stopper for fittings and building materials, guide, sash roller, angle; additionally, helmet, plastic model parts, core materials for tire, reel parts for fishing outfit, seals, packings and gland packing.
EXAMPLES
[0036] The present invention is hereinafter described more specifically by using Examples and yet is not limited to only the following Examples. Each physical property value in the following examples and comparative examples is measured as described below.
[0037] (LOI Value)
[0038] LOI value was measured in accordance with JIS L 1091 method.
[0039] (Flame Retardance)
[0040] Flame retardance was evaluated with a test piece (bar sample) having a thickness of 1/32 inch in conformity to the vertical flame test prescribed in UL94 of US. UL standard.
[0041] (CO Occurrence Amount)
[0042] CO concentration (%) in the whole combustion gas was measured when a test piece of a length of 100 mm×a side of 100 mm×a thickness of 3 mm was heated at a heat intensity of 50 kW/m 2 for 15 minutes in conformity to ISO 5660 by using a cone calorimeter III apparatus manufactured by Toyo Seiki Seisaku-sho, Ltd.
[0043] (Average Particle Diameter)
[0044] Average particle diameter was measured by a laser analytical scattering method.
Example 1
[0045] 3% by mass of a polyparaphenylene terephthalamide (PPTA) having an average particle diameter of 200 μm and 97% by mass of aluminum hydroxide (Al(OH) 3 : 99.5% by mass, Na 2 O: 0.25% by mass) having an average particle diameter of 10 μm were dry-blended at 600 rpm for 1 minute by a Henschel mixer. 50% by mass of the blend and 50% by mass of a linear low-density polyethylene (LLDPE) (trade name: NEOZEX2540R prime polymer) were melt-kneaded at a cylinder temperature of 280° C. and a screw speed of 220 rpm by a twin-screw extruder having a screw diameter of 45 mm manufactured by Toshiba Machine Co., Ltd. to form strand-shaped gut. The formed gut was cooled by a cooling bath and thereafter granulated by a cutter to obtain pellets. The obtained pellets were molded at a barrel temperature of 280° C. by using an injection molding machine IS100 manufactured by Toshiba Machine Co., Ltd. to obtain a molded product. The results of evaluating the molded product by the above-mentioned methods are shown in Table 1. Consequently, it is confirmed that flame retardance of the molded product subject to injection molding is remarkably improved.
Example 2
[0046] 3% by mass of a polyimide having an average particle diameter of 60 μm and 97% by mass of aluminum hydroxide (Al(OH) 3 : 99.5% by mass, Na 2 O: 0.25% by mass) having an average particle diameter of 10 μm were dry-blended at 600 rpm for 1 minute by a Henschel mixer. 50% by mass of the blend and 50% by mass of a linear low-density polyethylene (LLDPE) (trade name: NEOZEX2540R prime polymer) were blended to obtain pellets in the same manner as in Example 1, which obtained pellets were subject to injection molding to obtain a molded product. The results of evaluating the molded product by the above-mentioned methods are shown in Table 1. Consequently, it is confirmed that flame retardance of the molded product subject to injection molding is remarkably improved.
Comparative Example 1
[0047] 3% by mass of a polyimide having an average particle diameter of 5000 μm and 97% by mass of aluminum hydroxide (Al(OH) 3 : 99.5% by mass, Na 2 O: 0.25% by mass) having an average particle diameter of 10 μm shown in Table 1 were dry-blended at 600 rpm for 1 minute by a Henschel mixer. 50% by mass of the blend and 50% by mass of a linear low-density polyethylene (LLDPE) (trade name: NEOZEX2540R prime polymer) were extruded in the same manner as in Example 1, and then surge and vent-up were caused, so that pellets could not be obtained.
Comparative Example 2
[0048] 3% by mass of a polyphenylene sulfide (PPS) having an average particle diameter of 100 μm and 97% by mass of aluminum hydroxide (Al(OH) 3 : 99.5% by mass, Na 2 O: 0.25% by mass) having an average particle diameter of 10 μm shown in Table 1 were dry-blended at 600 rpm for 1 minute by a Henschel mixer. 50% by mass of the blend and 50% by mass of a linear low-density polyethylene (LLDPE) (trade name: NEOZEX2540R prime polymer) were blended to obtain pellets in the same manner as in Example 1, which obtained pellets were subject to injection molding to obtain a molded product. The results of evaluating the molded product by the above-mentioned methods are shown in Table 1. Consequently, flame retardance is deteriorated and CO occurrence amount is increased.
Comparative Example 3
[0049] 50% by mass of aluminum hydroxide (Al(OH) 3 : 99.5% by mass, Na 2 O: 0.25% by mass) having an average particle diameter of 10 μm and 50% by mass of a linear low-density polyethylene (LLDPE) (trade name: NEOZEX2540R prime polymer) shown in Table 1 were blended to obtain pellets in the same manner as in Example 1, which obtained pellets were subject to injection molding to obtain a molded product. The results of evaluating the molded product by the above-mentioned methods are shown in Table 1. Consequently, flame retardance was deteriorated.
Comparative Example 4
[0050] 50% by mass of a polyimide having an average particle diameter of 60 μm and 50% by mass of a linear low-density polyethylene (LLDPE) (trade name: NEOZEX prime polymer) shown in Table 1 were blended and extruded in the same manner as in Example 1, and attempted to be subject to injection molding but yet a predetermined product could not be obtained due to nozzle clogging.
[0051] The results in Table 1 showed that the case of only resin powder and only aluminum hydroxide did not bring a flame retardant satisfying both moldability and flame retardance. The case where the melting point of a resin blended with a flame retardant was low (PPS: 320° C.) brought poor flame retardance, and the case where resin particle diameter was too large brought poor molding. In examples of the present invention, the effects were excellent in flame retardance, LOI value and CO occurrence amount.
[0000]
TABLE 1
particle
diameter
Examples
Comparative Examples
components
(μm)
1
2
1
2
3
4
formulations
aromatic
100
3
polyamide
polyimide
60
3
100
polyimide
3000
3
PPS
50
3
aluminum
10
97
97
97
97
100
hydroxide
LLDPE
100
100
100
100
100
100
evaluations
flame
V0
V0
—
HB
HB
—
retardance
(UL94)
LOI
33
32
—
25
22
—
CO
not
not
—
5.3
0.5
—
occurrence
more
more
amount
than
than
(g/kg)
0.01
0.01
unit: part by mass
[0052] A flame retardant composition for a resin of the present invention is a halogen-free flame retardant, so that the blending with various kinds of resins allows flame retardance, and a flame-retardant resin composition to be obtained has excellent flame retardance and low smoking, so that the development into electrical applications around high voltage is greatly expected, such as electric wires, cables, transformers and resistors. | To provide a halogen-free flame retardant composition containing no antimony, phosphorus and phosphorus compounds at all, a non-halogen flame-retardant resin composition of environmental type ideal for disaster prevention made of the flame retardant composition, which causes little carbon monoxide (CO) during combustion while having high flame retardance, and molded products, electric wires, cables, fiber or fiber post-processed products made of the resin composition. The flame retardant composition comprises a mixture of (A) a resin having an average particle diameter of not more than 1000 μm selected from wholly aromatic polyamide, polyimide, polyamideimide, a copolymer of the wholly aromatic polyamide, the polyimide or the polyamideimide or a mixture of the above mentioned polymers and (B) a metal hydrate. The flame-retardant resin composition contains 50 to 200 parts by mass of the flame retardant composition to 100 parts by mass of a thermoplastic resin or a thermosetting resin. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a composite high frequency component and a mobile communication apparatus including the same, and more particularly to a composite high frequency component which can be used in three different communication systems and a mobile communication apparatus including the same.
[0003] [0003] 2 . Description of the Related Art
[0004] At present, as a mobile communication apparatus, a triple band portable telephone has been proposed which can be operated in plural frequency bands, for example, DCS (Digital Cellular System) and PCS (Personal Communication Services) which can be operated in the 1.8 GHz band, and GSM (Global System for Mobile communications) operative in the 900 MHz band.
[0005] [0005]FIG. 6 is a block diagram showing an example of the front end portion of a prior art triple band portable telephone. In this case, DCS and PCS using the 1.8 GHz band are employed as the first and second communication systems operative at adjacent frequencies, GSM operative in the 900 MHz band is employed as the third communication system applicable at a different frequency from the first and second communication systems.
[0006] The front end portion of the triple band portable telephone is provided with an antenna 1 , a diplexer 2 , first through third switches 3 through 5 having three ports, and first and second filters 6 and 7 . The diplexer 2 has the function of coupling a transmitting signal by DCS, PCS, or GSM in the case of transmitting, and distributing a receiving signal to DCS, PCS, or GSM in the case of receiving.
[0007] The first high frequency switch 3 switches the transmitting section side of DCS and PCS to the receiving section side of DCS and PCS and vice versa. The second high frequency switch 4 has the function of switching the receiving section Rxd side of DCS and the receiving section Rxp side of PCS and vice versa. The third high frequency switch 5 has the function of switching the transmitting section Txg side of GSM and the receiving section Rxg side thereof.
[0008] The first filter 6 has the function of passing a transmitting-receiving signal by DCS and PCS and attenuating second and third higher harmonics, and the second filter 7 functions in passing a transmitting-receiving signal by GSM and attenuating the third higher harmonic.
[0009] Hereinafter, the operation of a triple band portable telephone that operates by DSC will now be described. In the case of transmission, by connection of the transmitting section Txdp common to DCS and PCS by means of the first high frequency switch 3 , a transmitting signal from the transmitting section Txdp is sent to the first filter 6 . The transmitting signal that is passed through the first filter 6 is wave-associated in the diplexer 2 and sent through an antenna 1 . In the case of receiving, a receiving signal received through the antenna 1 is separated into its component waves in the diplexer 2 . The receiving signal from the antenna 1 is sent to the first filter 6 which is on the DCS and PCS side. With the first high frequency switch 3 , the receiving section side is turned on so that the receiving signal passed through the first filter 6 is sent to the second high frequency switch 4 . The receiving section Rxd of DCS is connected by means of the second high frequency switch 4 , so that the receiving signal passed through the second high frequency switch 4 is sent to the receiving section Rxd of DCS. When PCS is used, the transmission and-reception is achieved by a similar operation.
[0010] The case of GSM will now be described below. In the case of transmission, the transmitting section Txg is connected by means of the third high frequency switch 5 , so that a transmitting signal from the transmitting section Txg is sent to the second filter 7 . The transmitting signal passed through the second filter 7 is wave-associated in the diplexer 2 and sent through the antenna 1 . In the case of receiving, a receiving signal received through the antenna 1 is wave-branched in the diplexer 2 , and the receiving signal from the antenna 1 is sent to the second filter 7 which is on the GSM side. By connection of the receiving section Rxg by means of the third high frequency switch 5 , the receiving signal passed through the second filter 7 is sent to the receiving section Rxg.
[0011] However, in the above-described prior art triple band portable telephone mobile communication apparatus, the two high frequency switches are provided on the first and second communication system side, where the systems are operative at adjacent frequencies. Accordingly, the insertion loss due to the two high frequency switches occurs in the receiving sections. Thus, a problem exists in that the insertion loss is increased.
[0012] Further, the area which is occupied by the high frequency switches is large, and the circuit substrate is voluminous. As a result, there is also a problem in that the size of the triple band portable telephone (mobile communication apparatus) is large.
SUMMARY OF THE INVENTION
[0013] To overcome the above described problems, one embodiment of the present invention provides a composite high frequency component, comprising: a front end portion comprising a first communication system and a second communication system operative at adjacent frequencies to each other and a third communication system operative at a frequency different from those of the first and second communication systems; a diplexer for coupling a transmitting signal from said first, second and third communication systems in the case of transmission and for distributing a receiving signal to said first, second and third communication systems in the case of reception; a first high frequency switch having four ports for separating into a transmitting section common to said first and second communication systems, a receiving section of said first communication system, and a receiving section of said second communication system; a second high frequency switch having three ports for separating into transmitting and receiving sections of said third communication system; a first filter for passing a transmitting-receiving signal by said first and second communication systems; and a second filter for passing a transmitting-receiving signal by said third communication system.
[0014] According to the above described structure and arrangement, the two high frequency switches, that is, the first high frequency switch having the four ports and the second high frequency switch having the three ports are included. Thus, only the first high frequency switch are provided in the receiving path for the first and second communication systems operative at adjacent frequencies. As a result, the insertion loss in the receiving sections is reduced.
[0015] The two high frequency switches included in the composite high frequency component can be formed of the five-diodes. Thus, the composite high frequency component can be miniaturized and produced inexpensively.
[0016] In the above described composite high frequency component, the on-off of the first high frequency switch may be controlled with a first controlling power supply connected to the transmitting section side common to the first and second communication systems, a second controlling power supply connected to the receiving section side of the first communication system, and a third controlling power supply connected to the receiving section side of the second communication system; and the on-off of the second high frequency switch may be controlled with a fourth controlling power supply connected to the transmitting section side of the third communication system, and a fifth controlling power supply connected to the receiving section side of the third communication system.
[0017] According to the above described structure and arrangement, the on-off of the first high frequency switch is controlled by means of the first through third controlling power supplies, and the on-off of the second high frequency switch by means of the fourth and fifth controlling power supplies. Thus, in transmission by the first and second communication systems operative at adjacent frequencies, all the three diodes constituting the first high frequency switch having the four ports are turned on. Thus, the higher harmonic distortion of the composite high frequency component can be reduced.
[0018] In the above described-composite high frequency component, the on-off of the first high frequency switch may be controlled with first and second controlling power supplies connected to two selected from the transmitting section side common to the first and second communication systems, the receiving section side of the first communication system, and the receiving section side of the second communication system; and the on-off of the second high frequency switch may be controlled with a third controlling power supply connected to one of the transmitting section side of the third communication system and the receiving section side of the third communication system.
[0019] According to the above described structure and arrangement, the on-off of the first high frequency switch is controlled by means of the first and second controlling power supplies, and the on-off of the second high frequency switch by means of the third controlling power supply. Accordingly, in receiving by either one of the first and second communication systems which are in the post-stage of the first high frequency switch, or in receiving by the third communication system which is in the post-stage of the second high frequency switch, the voltages applied to the first and second controlling power supplies provided for the first high frequency switch, and the voltage applied to the third controlling power supply provided for the second high frequency switch become 0V. As a result, the consumption current of the composite high frequency component can be reduced.
[0020] In the above described composite high frequency component, at least one of the first and second filters may be arranged in the post-stage on the transmitting section side of the first and second high frequency switches.
[0021] According to the above described structure and arrangement, at least one of the first and second filters is arranged in the post-stage, or on the transmitting section side, of the high frequency switch. Thus, the distortion of a transmitting signal caused by a high-power amplifier, can be attenuated. Thus, the insertion loss in the receiving sections can be improved.
[0022] In the above described composite high frequency component, the diplexer, the first and second high frequency switches, and the first and second filters may be integrated with a ceramic multi-layer substrate formed by laminating a plurality of ceramic sheet layers.
[0023] According to the above described structure and arrangement, the diplexer, the high frequency switches, and the filters, which constitute the composite high frequency component, are integrated into the ceramic multi-layer substrate formed by lamination of ceramic plural sheet layers. Accordingly, the matching-adjustment between the diplexer and the respective high frequency switches can be easily achieved. It is unnecessary to provide a matching circuit between the diplexer and the high frequency switches and between the high frequency switches and the filters.
[0024] Accordingly, since the number of elements can be reduced, the circuit substrate for forming a microwave circuit with plural signal paths can be miniaturized.
[0025] In the above described composite high frequency component, the diplexer may comprise a first inductance element, and a first capacitance element; the first high frequency switch may comprise a first switching element, a second inductance element, and a second capacitance element; the second high frequency switch may comprise a second switching element, a third inductance element, and a third capacitance element; the first filter may comprise a fourth inductance element and a fourth capacitance element; the second filter may comprise a fifth inductance element and a fifth capacitance element; and the first and second switching elements, the first through fifth inductance elements, and the first through fifth capacitance elements may be contained in or mounted onto the ceramic multi-layer substrate, and connected with a connecting means formed inside of the ceramic multi-layer substrate.
[0026] According to the above described structure and arrangement, the diplexer is composed of the first inductance elements and the first capacitance elements, each of the first through third high frequency switches of the first and second switching elements, the second inductance elements, and the second capacitance elements, each of the first ad second filters of the third inductance elements and the third capacitance elements. They are contained in or mounted onto the ceramic multi-layer substrate and connected with the connecting means. Thus, the composite high frequency component can be formed by use of one ceramic multi-layer substrate, and can be further miniaturized. In addition, the loss due to the wiring between its elements can be improved.
[0027] Further, with the wavelength shortening effects, the strip-line electrodes which become the respective inductance elements can be shortened. Thus, the insertion losses due to these strip-line electrodes can be improved. As a result, the composite high frequency component can be miniaturized, and the reduction of the loss can be realized.
[0028] Another preferred embodiment of the present invention provides a mobile communication apparatus including any one of the above described composite high frequency components.
[0029] The above described mobile communication apparatus includes the composite high frequency component of the present invention, which is small in size and has a low loss. Accordingly, the mobile communication apparatus having the composite high frequency component mounted thereto can be miniaturized and enjoy high quality operation.
[0030] Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0031] [0031]FIG. 1 is a circuit diagram of a composite high frequency component according to a first embodiment of the present invention.
[0032] [0032]FIG. 2 is an exploded perspective view of a part of the composite high frequency component shown in FIG. 1.
[0033] [0033]FIG. 3 is a circuit diagram of a composite high frequency component according to a second embodiment of the present invention.
[0034] [0034]FIG. 4 is a block diagram of a composite high frequency component according to a third embodiment of the present invention.
[0035] [0035]FIG. 5 is a block diagram showing a part of a mobile communication apparatus including the composite high frequency component shown in FIG. 1.
[0036] [0036]FIG. 6 is a block diagram showing the front end portion of a generally-used triple band portable telephone (mobile communication apparatus).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] [0037]FIG. 1 is a circuit diagram of a first embodiment of a composite high frequency component according to the present invention. A composite high frequency component 10 , which constitutes partially a front end portion corresponding to a first, second, and third communication system, namely, DCS (1.8 GHz band), PCS (1.8 GHz band), and GSM (900 MHz band). The front end portion is composed of a diplexer 11 , a first high frequency switch 12 having four ports, a second high frequency switch 13 having three ports, and first and second filters 14 and 15 .
[0038] An antenna 1 is connected to the first port P 11 of diplexer 11 . The first port P 41 of first filter 14 is connected to the second port P 12 of diplexer 11 , and the first port P 51 of second filter 15 is connected to the third port P 13 of diplexer 11 .
[0039] The first port P 21 of first high frequency switch 12 is connected to the second port P 42 of the first filter 14 . The transmitting section Txdp common to DCS and PCS is connected to the second port P 22 of the first high frequency switch 12 . The receiving section Rxd of DCS is connected to the third port P 23 of first high frequency switch 12 . The receiving section Rxp of PCS is connected to the fourth port P 24 of first high frequency switch 12 .
[0040] Further, the first port P 31 of second high frequency switch 13 is connected to the second port P 52 of the second filter 15 . The transmitting section Txg of GSM is connected to the second port P 32 of the second high frequency switch 13 . The receiving section Rxg of GSM is connected to the third port P 33 of the second high frequency switch 13 .
[0041] The diplexer 11 is composed of first inductors L 11 and L 12 which are first inductance elements, and first capacitors C 11 through C 15 which are first capacitance elements.
[0042] The first capacitors C 11 and C 12 are connected in series between the first port P 11 and the second port P 12 , and their common node is,grounded through a series combination of the first inductor L 11 and the first capacitor C 13 .
[0043] A parallel circuit comprising the first inductor L 12 and the first capacitor C 14 is connected between the first port P 11 and the third port P 13 . This parallel circuit at the third port P 13 is grounded through the first capacitor C 15 .
[0044] The first high frequency switch 12 is composed of first diodes D 11 through D 13 which are first switching elements, second inductors L 21 through L 25 which are second inductance elements, and second capacitors C 21 through C 25 which are second capacitance elements.
[0045] The first diode D 11 is connected between the first port P 21 and the second port P 22 such that its cathode is at the first port P 21 . A series circuit comprising the second inductor L 21 and the second capacitor C 21 is connected in parallel with the first diode D 11 .
[0046] The anode of the first diode D 11 is grounded through a series combination of the second inductor L 22 and the second capacitor C 22 . The common node between the second inductor L 22 and the second capacitor C 22 is provided with a first controlling terminal Vc 1 .
[0047] The second inductor L 23 is connected between the first port P 21 and the third port P 23 . The second inductor L 23 at the third port P 23 is grounded through a series combination of the first diode D 12 and the second capacitor C 23 (with the anode of diode D 12 being connected to third port P 23 ). The common node between the cathode of the first diode D 12 and the second capacitor C 23 is provided with a second controlling terminal Vc 2 .
[0048] The second inductor L 24 is connected between the first port P 21 and fourth port P 24 . The second inductor L 24 at the fourth port P 24 is grounded through a series combination of the first diode D 13 and the second capacitor C 24 (with the anode of diode D 12 being connected to fourth port P 24 ). The common node between the cathode of the first diode D 13 and the second capacitor C 24 is provided with a third controlling terminal Vc 3 .
[0049] The first port P 21 is grounded through a series combination of the second inductor L 25 and the second capacitor C 25 . The common node between the second inductor L 25 and the second capacitor C 25 is grounded through a resistor R.
[0050] The second high frequency switch 13 is composed of second diodes D 21 and D 22 which are second switching elements, third inductors L 31 trough L 33 which are third inductance elements, and third capacitors C 31 through C 33 which are third capacitance elements.
[0051] The second diode D 21 is connected between the first port P 31 and the second port P 32 such that its cathode is at the first port P 31 . A series circuit comprising the third inductor L 31 and the third capacitor C 31 is connected in parallel with the second diode D 21 .
[0052] The anode of the second diode D 21 is grounded through a series combination of the third inductor L 32 and the third capacitor C 32 . The common node between the third inductor L 32 and the third capacitor C 32 is provided with a fourth controlling terminal Vc 4 .
[0053] The third inductor L 33 is connected between the first port P 31 and the third port P 33 . The third inductor L 33 at the third port P 33 is grounded through a series combination of the second diode D 22 and the third capacitor C 33 . The common node between the cathode of the second diode D 22 and the third capacitor C 33 is provided with a fifth controlling terminal Vc 5 .
[0054] The first filter 14 is composed of a fourth inductor L 41 which is a fourth inductance element, and fourth capacitors C 41 and C 42 which are fourth capacitance elements.
[0055] The fourth inductor L 41 is connected in series between the first port P 41 and the second port P 42 . The fourth capacitor C 41 is connected in parallel with the fourth inductor L 41 . The fourth inductor L 41 at the second port P 42 is grounded through the fourth capacitor C 42 .
[0056] The second filter 15 is composed of a fifth inductor L 51 which is a fifth inductance element, and fifth capacitors C 51 and C 52 which are fifth capacitance elements.
[0057] The fifth inductor L 51 is connected in series between the first port P 51 and the second port P 52 . The fifth capacitor C 51 is connected in parallel with the fifth inductor L 51 . The fifth inductor L 51 at the second port P 52 is grounded through the fifth capacitor C 52 .
[0058] [0058]FIG. 2 is an exploded perspective view of a part of the composite high frequency component having the circuit arrangement shown in FIG. 1. The composite high frequency component 10 contains a ceramic multi-layer substrate 16 . The ceramic multi-layer substrate 16 contains the first inductors L 11 and L 12 , and the first capacitors C 11 through C 15 which make up the diplexer 11 , the second inductors L 21 and L 23 through L 25 , the second capacitors C 21 , C 22 , and C 25 of the first high frequency switch 12 , the third inductors L 31 and L 33 , and the third capacitors C 31 and C 32 of the second high frequency switch 13 , the fourth inductor L 41 and the fourth capacitors C 41 and C 42 which constitute the first filter 14 , and the fifth inductor L 51 and the fifth capacitors C 51 and C 52 which constitute the second filter 15 , respectively, tough they are not shown in the figure.
[0059] On the surface of the ceramic multi-layer substrate 16 , the first diodes D 11 through D 13 , the second inductor L 22 , the second capacitors C 23 and C 24 which constitute the first high frequency switch 12 , and the second diodes D 21 and D 22 , the third inductor L 32 , and the third capacitor C 33 which constitute the second high frequency switch 13 , are mounted in the form of chip elements.
[0060] Twelve external terminals Ta through Tl are formed to extend from a side face onto a bottom of the ceramic multi-layer substrate 16 by screen printing or the like. The five external terminals Ta through Te are formed on one long-side portion of the ceramic multi-layer substrate 11 , the five external terminals Tg through Tk are formed on the other long-side portion of the ceramic multi-layer substrate 11 , and the remaining two external terminals Tf and Tl are formed on the opposite short-side portions of the ceramic multi-layer substrate 11 , respectively, by screen printing or the like.
[0061] The external terminals Ta through Tl are used as the port P 11 of the diplexer 11 , the second and third ports P 22 , P 23 , P 32 , and P 33 of the first and second high frequency switches 12 and 13 , the first through fifth controlling terminals Vc 1 , Vc 2 , Vc 3 , Vc 4 , and Vc 5 of the first and second high frequency switches 12 and 13 , and terminals for grounding.
[0062] A metallic cap 17 covers the ceramic multi-layer substrate 16 in such a manner as to coat the surface of the ceramic multi-layer substrate 16 . In this case, the metallic cap 17 is connected to the external terminals Tf and Tl applicable as terminals for grounding which are provided on the respective opposite short-side portions of the ceramic multi-layer substrate 16 .
[0063] The operation of the composite high frequency component 10 having the circuit arrangement shown in FIG. 1 will be now described. First, if a transmitting signal by DCS or PCS (1.8 GHz band) is transmitted, 1V is applied to the first controlling terminal Vc 1 , 1V is applied to the second controlling terminal Vc 2 , and 1V is applied to the third controlling terminal Vc 3 , respectively, in the first high frequency switch 12 , so that the first port P 21 and the second port P 22 of the first high frequency switch 12 are connected, and thereby, the transmitting signal by DCS or PCS is passed through the first high frequency switch 12 , the first filter 14 , and the diplexer 11 , and sent through the antenna 1 . In this case, the first filter 14 allows the transmitting signal by DCS or PCS to pass and attenuates the second and third higher harmonics.
[0064] On the other hand, in the second high frequency switch 13 , 0V is applied to the fourth controlling terminal Vc 4 , and 1V is applied to the fifth controlling terminal vc 5 , respectively, so that the second high frequency switch 13 is cut off.
[0065] Further, in the case that a transmitting signal by GSM (900 MHz band) is transmitted, 1V is applied to the fourth controlling terminal Vc 4 , and 0V is applied to the fifth controlling terminal Vc 5 , respectively, in the second high frequency switch 13 so that the first port P 31 and second port P 32 of the second high frequency switch 13 are connected, and thereby, the transmitting signal by GSM is passed through the second high frequency switch 13 , the second filter 15 , and the diplexer 11 , and sent through the antenna 1 by GSM. In this case, the second filter 15 allows the transmitting signal to pass and attenuates the third higher harmonic.
[0066] On the other hand, in the first high frequency switch 12 , 0V is applied to the first controlling terminal Vc 1 , 0V is applied to the second controlling terminal Vc 2 , and 0V is applied to the third controlling terminal Vc 3 , respectively, so that the first high frequency switch 12 is cut off.
[0067] Further, in the case that a receiving signal by DCS is received, 0V is applied to the first controlling terminal Vc 1 , 0V is applied to the second controlling terminal Vc 2 , and 1V is applied to the third controlling terminal Vc 3 , respectively, in the first high frequency switch 12 , so that the first port P 21 and the third port P 23 of the first high frequency switch 12 are connected, and thereby, the receiving signal by DCS received through the antenna 1 is passed through the diplexer 11 , the first filter 14 , and the first high frequency switch 12 , and sent to the receiving section Rxd of DCS. In this case, the first filter 14 allows the receiving signal by DCS to pass and attenuates the second and third higher harmonics.
[0068] In the second high frequency switch 13 , 0V is applied to the fourth controlling terminal Vc 4 , and 1V is applied to the fifth controlling terminal Vc 5 , respectively, so that the second high frequency switch 14 is cut off.
[0069] Further, in the case that the receiving signal by PCS is received, 0V is applied to the first controlling terminal Vc 1 , 1V is applied to the second controlling terminal Vc 2 , and 0V is applied to the third controlling terminal Vc 3 , respectively, in the first high frequency switch 12 , so that the first port P 21 and the fourth port P 24 of the first high frequency switch 12 are connected, and thereby, the receiving signal by PCS received through the antenna 1 is passed through the diplexer 11 , the first filter 14 , and the first high frequency switch 12 , and sent to the receiving section Rxp of PCS. In this case, the first filter 14 allows the receiving signal by PCS to pass and attenuates the second and third higher harmonics.
[0070] On the other hand, in the second high frequency switch 13 , 0V is applied to the fourth controlling terminal Vc 4 , and 1V is applied to the fifth controlling terminal Vc 5 , respectively, so that the second high frequency switch 13 is cut off.
[0071] Further, in the case that a receiving signal by GSM is received, 0V is applied to the fourth controlling terminal Vc 4 , and 1V is applied to the fifth controlling terminal Vc 5 , respectively, in the second high frequency switch 13 , so that the first port p 31 and the third port P 33 of the second high frequency switch 13 are connected, and thereby, the receiving signal by GSM received through the antenna 1 is passed through the diplexer 11 , the second filter 15 , and the second high frequency switch 13 , and sent to the receiving section Rxg by GSM. In this case, the second filter 15 allows the receiving signal by GSM to pass and attenuates the third higher harmonic.
[0072] In the first high frequency switch 12 , 0V is applied to the first controlling terminal Vc 1 , 0V is applied to the second controlling terminal Vc 2 , and 0V is applied to the third controlling terminal Vc 3 , respectively, and thereby, the first high frequency switch 12 is cut off.
[0073] Since the above-described composite high frequency component of the first embodiment includes two high frequency switches, that is, the first high frequency switch having the four ports and the second high frequency switch having the three ports, it is possible that only the first high frequency switch is provided in the receiving path of the first and second communication systems operative at adjacent frequencies, and thereby, the insertion loss in the receiving sections is reduced.
[0074] The two high frequency switches which constitute the composite high frequency component are advantageously formed using five diodes. This enables the miniaturization of the composite high frequency switch and production at low cost.
[0075] Further, the on-off of the first high frequency switch is controlled by means of-the first through third controlling power supplies, and the on-off of the second high frequency switch is controlled by means of the fourth and fifth controlling power supplies. Thus, in the case of transmission by DCS or PCS (which may be operative at adjacent frequencies), all of the three diodes making up the first high frequency switch having the four ports are turned on. As a result, the higher harmonic distortion of the composite high frequency component can be reduced.
[0076] The diplexer, the first and second high frequency switches, and the first and second filters, which constitute the composite high frequency component, are integrated into the ceramic multi-layer substrate formed by laminating the ceramic sheet layers. Thus, the matching, attenuation, and isolation characteristics of the respective elements can be assured, and thereby, a matching network disposed between the diplexer and the first and second high frequency switches becomes unnecessary.
[0077] Accordingly, the composite high frequency component can be miniaturized. For example, the diplexer, the first and second high frequency switches, and the first and second filters can be integrated into the ceramic multi-layer substrate with a size of 6.3 mm×5 mm×2 mm.
[0078] Further, the diplexer is made up of the first inductors and the first capacitors. The first high frequency switch is composed of the first diodes, the second inductors, and the second capacitors. The second high frequency switch is composed of the second diodes, the third inductors, and the third capacitors. The first filter is formed of the fourth inductor and the fourth capacitors. The second filter is composed of the fifth inductor, and the fifth capacitors. They are contained in or mounted onto the ceramic multi-layer substrate, and connected by use of a connecting apparatus which is formed inside the ceramic multi-layer substrate. Thus, the composite high frequency component can be formed on one ceramic multi-layer substrate, that is, the component can be miniaturized. In addition, any losses caused by wiring between elements can be improved. As a result, the overall loss of the composite high frequency component can be reduced.
[0079] Further, owing to the wavelength shortening effect, the lengths of the strip-line electrodes, which are the first through fifth inductors, can be shortened. Thus, the insertion loss, caused by these strip-line electrodes, can be improved. As a result, the miniaturization and low loss of the composite high frequency component can be realized.
[0080] [0080]FIG. 3 is a circuit diagram of the composite high frequency component according to a second embodiment of the present invention. The composite high frequency component 20 is composed of a diplexer 11 , first and second high frequency switches 12 and 13 , and first and second filters 14 and 15 .
[0081] The arrangements of the diplexer 11 and the first and second filters 14 and 15 are the same as those in the composite high frequency component 10 of the first embodiment shown in FIG. 1. Their detailed description will be omitted.
[0082] The first high frequency switch 12 is composed of the first diodes D 11 through D 13 which are first switching elements, the second inductors L 21 through L 25 which are second inductance elements, and the second capacitors C 21 through C 25 which are second capacitance elements.
[0083] The first diode D 11 is connected between the first port P 21 and the second port P 22 such that its cathode is at the first port P 21 . A series circuit comprising the second inductor L 21 and the second capacitor C 21 is connected in parallel with the first diode D 11 .
[0084] Further, the anode of the first diode D 11 is grounded through a series combination the second inductor L 22 and the second capacitor C 22 . The common node between the second inductor L 22 and the second capacitor C 22 is provided with the first controlling terminal Vc 1 .
[0085] The second inductor L 23 is connected between the first port P 21 and the third port P 23 . The second inductor L 23 at the third port P 23 is grounded through a series combination the first diode D 12 and the second capacitor C 23 . The common node between the cathode of the first diode D 12 and the second capacitor C 23 is grounded through the resistor R.
[0086] The first diode D 13 is connected between the first port P 21 and the fourth port P 24 such that its cathode is at the first port P 21 . A series circuit comprising the second inductor L 24 and the second capacitor C 24 is connected in parallel with the first diode D 13 .
[0087] The anode of the first diode D 13 is grounded through a series combination the second inductor L 25 and the second capacitor C 25 . The common node between the second inductor L 25 and the second capacitor C 25 is provided with the second controlling terminal Vc 2 .
[0088] The second high frequency switch 13 is composed of the second diodes D 21 and D 22 which are second switching elements, the third inductors L 31 through L 33 which are third inductance elements, and third capacitors C 31 through C 33 which are third capacitance elements.
[0089] The second diode D 21 is connected between the first port P 31 and the second port P 32 such that its cathode is at the first port P 31 . A series circuit comprising the third inductor L 31 and the third capacitor C 31 is connected in parallel with the second diode D 21 .
[0090] The anode of the second diode-D 21 is grounded through a series combination the third inductor L 32 and the third capacitor C 32 . The common node between the third inductor L 32 and the third capacitor C 32 is provided with the third controlling terminal Vc 3 .
[0091] The third inductor L 33 is connected between the first port P 31 and the third port P 33 . The third port P 33 side of the third inductor L 33 is grounded through a series combination the second diode D 22 and the third capacitor C 33 . The common node between the cathode of the second diode D 22 and the third capacitor C 33 is grounded through the resistor R.
[0092] Hereinafter, the operation of the composite high frequency component 20 having the circuit arrangement shown in FIG. 3 will be described. If a transmitting signal by DCS or PCS (1.8 GHz) is transmitted, 1V is applied to the first controlling terminal Vc 1 and 0V is applied to the second controlling terminal Vc 2 , respectively, in the first high frequency switch 12 , so that the first port P 21 and the second port P 22 of the first high frequency switch 12 are connected, and thereby, the transmitting signal by DCS or PCS is passed through the first high frequency switch 12 , the first filter 14 , and the diplexer 11 , and sent through the antenna 1 . In this case, the first filter 14 allows the transmission signal by DCS and PCS to pass and attenuates the second and third harmonics.
[0093] In the second high frequency switch 13 , 0V is applied to the third controlling terminal Vc 3 so that the second high frequency switch 13 is cut off.
[0094] Further, in the case that a transmitting signal by GSM (900 MHz band) is transmitted, 1V is applied to the third controlling terminal Vc 3 in the second high frequency switch 13 so that the first port P 31 and the second port P 32 of the second high frequency switch 13 are connected, and thereby, the transmitting signal by GSM is passed through the second high frequency switch 13 , the second filter 15 , and the diplexer 11 , and sent through the antenna 1 . In this case, the second filter 15 allows the transmitting signal by GSM to pass and attenuates the third harmonic.
[0095] On the other hand, in the first high frequency switch 12 , 0V is applied to the first controlling terminal Vc 1 , and 0V is applied to the second controlling terminal Vc 2 , respectively, so that the first high frequency switch 12 is cut off.
[0096] Further, if a receiving signal by DCS is received, 0V is applied to the first controlling terminal Vc 1 , and 0V is applied to the second controlling terminal Vc 2 , respectively, in the first high frequency switch 12 , so that the first port P 21 and the third port P 23 of the first high frequency switch 12 are connected, and thereby, the receiving signal by DCS received through the antenna 1 is passed trough the diplexer 11 , the first filter 14 , and the first high frequency switch 12 , and sent to the receiving section Rxd of DCS. In this case, the-first filter 14 allows the receiving signal by DCS to pass and attenuates the second and third harmonics.
[0097] On the other hand, in the second high frequency switch 13 , 0V is applied to the third controlling terminal Vc 3 so that the second high frequency switch 13 is cut off.
[0098] Further, if a receiving signal by PCS is received, 0V is applied to the first controlling terminal Vc 1 , and 1V is common to the second controlling terminal Vc 2 , respectively, in the first high frequency switch 12 , so that the first port P 21 and the fourth port P 24 of the first high frequency switch 12 are connected, and thereby, the receiving signal by PCS received through the antenna 1 is passed through the diplexer 11 , the first filter 14 , and the first high frequency switch 12 , and sent to the receiving section Rxp of PCS. In this case, the first filter 14 allows the receiving signal by PCS to pass and attenuates the second and third higher harmonics.
[0099] On the other hand, in the second high frequency switch 13 , 0V is applied to the third controlling terminal Vc 3 , so that the third high frequency switch 13 is cut off.
[0100] Further, in the case that a receiving signal by GSM is received, 0V is applied to the third controlling terminal Vc 3 in the second high frequency switch 13 , so that the first port P 31 and the third port P 33 of the second high frequency switch 13 are connected, and thereby, the receiving signal by GSM received through the antenna 1 is passed through the diplexer 11 , the second filter 15 , and the second high frequency switch 13 , and sent to the receiving section Rxg of GSM. In this case, the second filter 15 allows the receiving signal by GSM to pass and attenuates the third higher harmonic.
[0101] In the first high frequency switch 12 , 0V is applied to the first controlling terminal Vc 1 , and 0V is applied to the second controlling terminal Vc 2 , respectively, so that the first high frequency switch 12 is cut off.
[0102] In the composite high frequency component according to the above-described second embodiment, the on-off of the first high frequency switch is controlled by means of the first and second controlling power supplies, and the on-off of the second high frequency switch is controlled by means of the third controlling power supply. Thus, when DCS, which is in the post-stage of the first high frequency switch, and GSM in the post-stage of the second high frequency switch operate to receive, the voltages to-be applied to the first and second controlling power supplies with which the first high frequency switch is provided, and the voltage to be applied to the third controlling power supply with which the second high frequency switch is provided become 0V. As a result, the consumption current of the composite high frequency component can be reduced.
[0103] [0103]FIG. 4 is a block diagram of the composite high frequency component according to the third preferred embodiment of the present invention. The composite high frequency component 30 is different from the composite high frequency component 10 of the first embodiment (FIG. 1) in the arrangement and position of the first and second filters 14 and 15 .
[0104] The first filter 14 is arranged in the post-stage or on the transmitting section side of the first high frequency switch 12 , i.e., on the transmitting section Txdp side common to DCS and PCS. The second filter 15 is provided between the second high frequency switch 13 and the transmitting section Txg of GSM which is in the post-stage or on the transmitting section side of the second high frequency switch 13 .
[0105] In the above-described composite high frequency component of the third embodiment, each filter is arranged in the post-stage or on the transmitting section side of the high frequency switch, i.e., between the high frequency switch and the transmitting section. Thus, in transmission, distortions in high-power amplifiers provided in the transmitting sections can be reduced by means of the filters, respectively. Thus, an insertion loss on the receiving side can be improved.
[0106] [0106]FIG. 5 is a block diagram showing a part of the configuration of a triple band portable telephone (a type of mobile communication apparatus) and illustrates, as an example, a combination of DCS and PCS operative in the 1.8 GHz band and GSM in the 900 MHz band. The triple band portable telephone 40 is provided with the antenna 1 and the composite high frequency component 10 (FIG. 1).
[0107] The antenna 1 is connected to port P 11 of the composite high frequency component 10 . Ports P 22 , P 23 , P 24 , P 32 , and P 33 are connected to the transmitting section Txdp common to DCS and PCS, the receiving section Rxp of PCS, the receiving section Rxd of DCS, the transmitting section Txg of GSM, and the receiving section Rxg of GSM, respectively.
[0108] In the above-described triple band portable telephone, the composite high frequency component which is small in size and has a low loss is employed. Thus, the mobile communication apparatus having the composite high frequency component mounted thereon can be miniaturized and enjoy high quality operation.
[0109] If the composite high frequency components 20 and 30 (FIGS. 2 and 3) are employed instead of the composite high frequency component 10 , respectively, similar effects can be obtained.
[0110] While the invention has been particularly shown and described with reference to preferred embodiments 15 thereof, it will be understood by those skilled in the art that the forgoing and other changes in form and details may be made therein without departing from the spirit of the invention. | A composite high frequency component, comprising: a first high frequency switch having a first common port and firsts second, and third communication ports, wherein: the first communication port is operable to connect to respective transmitting sections of first and second communication systems which operate in substantially the same frequency band, the second communication port is operable to connect to a receiving section of the first communication system, the third communication port is operable to connect to a receiving section of the second communication system, and the first high frequency switch has a transfer characteristic for passing signals between the first common port and the first, second and third communication ports which are in the frequency band of the first and second communication systems as a function of at least one first control signal; a second high frequency switch having a second common port and fourth and fifth communication ports, wherein: the fourth communication port is operable to connect to a transmitting section of a third communication system which operates in a different frequency band than the first and second communication systems, the fifth communication port is operable to connect to a receiving section of the third communication system, and the second high frequency switch has a transfer characteristic for passing signals between the second common port and the fourth and fifth communication ports which are in the frequency band of the third communication system as a function of at least one second control signal; a first filter having a transfer characteristic for passing signals in the frequency band of the first and second communication systems, one end of the first filter being coupled to the first common port of the first high frequency switch; a second filter having a transfer characteristic for passing signals in the frequency band of the third communication system, one end of the second filter being coupled to the second common port of the second high frequency switch; and a diplexer having a third common port and first and second input/output ports, wherein: the third common port is operable to at least one of receive and transmit signals from an antenna, the first input/output port is coupled to an opposite end of the first filter, the second input/output port is coupled to an opposite end of the second filter, and the diplexer has a transfer characteristic for passing signals: (i) between the third common port and the first input/output port which are in the frequency band of the first and second communication systems, and (ii) between the third common port and the second input/output port which are in the frequency band of the third communication system. | 7 |
FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a contact arrangement for a vacuum switching tube having a contact carrier and a contact piece that is joined to the contact carrier in a vacuum using a soldering material.
RELATED TECHNOLOGY
A method for manufacturing a contact arrangement for a vacuum chamber is described in German Patent Document No. 196 32 573 A1, in which the contact carrier in a vacuum is coated with a contact layer through sintering an appropriate powder and its subsequent solidifying. It is further known to solder a contact carrier to a contact piece in a vacuum using a soldering material that is arranged in between, by melting the soldering material and pressing contact carrier and contact piece together. Mechanical, frictional-locking bonds between contact piece and contact carrier are also known, reference being made, by way of example, to German Patent Document No. 44 47 391 C1 and German Patent Document No. 195 34 398 A1.
In FIGS. 1 a and 1 b , there is a schematic illustration of a known method for producing a soldered connection between a contact carrier 1 and a contact piece 10 using an intermediate layer of a soldering material 11 , for example a soldering disk. In this context, contact piece 10 is preferably provided with a saucer-shaped recess 101 , into which are set soldering disk 11 and then contact carrier 1 at its mounting end. After being heated in the vacuum, soldering disk 11 melts and produces soldered connection 30 between contact carrier 1 and contact piece 10 . In this method, it is disadvantageous that in the hanging arrangement of contact piece 10 on contact carrier 1 , a sufficient positive locking between contact piece and contact carrier must be present during the production of the soldered connection in order to prevent contact piece 10 from falling away in the melting of the soldering disk. In the hanging arrangement, in the case of larger contact pieces, it is frequently necessary, during the soldering process in the vacuum, to employ auxiliary structures in order to prevent the contact piece from falling away or, on the other hand, to provide for a supplementary positive locking of contact piece 10 on contact carrier 1 .
SUMMARY OF THE INVENTION
An objective of the present invention is to provide a method by which a contact arrangement having soldered bonding sites can be manufactured reliably and more simply using a smallest possible optimal quantity of soldering material.
The present invention provides a method by which the contact piece is directly pressed flat onto the contact carrier, leaving a gap along the contact surface, and the soldering material is arranged in areas directly bordering on the gap of the contact surface between the contact piece and the contact carrier, and subsequently, in a vacuum, through applying heat, the soldering material is brought to the melting point and the melted soldering material penetrates into the gap of the contact surfaces between the contact carrier and the contact piece.
The method according to the present invention can be applied with particular advantage to the manufacture of contact arrangements for vacuum switching tubes. The method according to the present invention makes it possible for the contact surface between contact carrier and contact piece to be wetted with soldering material on virtually its entire surface, i.e., sufficiently. In addition, the bond between contact carrier and contact piece is strengthened through the melted soldering material rising in the gap—the annular gap—between contact carrier and contact piece, the gap being mainly vertical and, towards the exterior, adjoining the contact surface between contact carrier and contact piece. Depending on the type of configuration, an optimal dosing is possible of the quantity of soldering material that is required to achieve the sufficient soldered connection between contact carrier and contact piece. In particular, the method according to the present invention makes it possible, in a simple manner, to produce a contact carrier having a contact piece hanging from it, i.e., in the hanging position. Applying the method according to the present invention to the production of vacuum switching tubes makes it possible to manufacture, for example, all of the soldering points of a preassembled vacuum switching tube in one processing step, i.e., in one oven cycle.
According to one version of the present invention, a contact piece is used that has a planar, saucer-shaped recess, into which the contact carrier at its mounting end is set, an annular gap between contact piece and contact carrier being formed at the planar gap of the contact surface, and the soldering material being placed in ring-like fashion around the contact carrier at the annular gap emerging between contact carrier and contact piece, so that after the melting, the soldering material is pulled by gravity and capillary action into the annular gap and the gap along the saucer-shaped recess. In this variant of the method according to the present invention, a virtually full-surface wetting of the contact surface between the contact carrier and the contact piece is achieved by the molten soldering material flowing and pressing into the gap from the sides. In addition, however, as a result of the solder collecting in the lateral vertical gaps, a good bond of great stability is achieved between contact carrier and contact piece.
According to a further version of the present invention, however, it is also possible to introduce the soldering material via bore holes that lead through the contact carrier to the contact surface between the contact carrier and contact piece. According to one version of the present invention, a contact piece is used that has a planar, saucer-shaped recess, into which the contact carrier at its mounting end is set, and, additionally, a contact carrier is used, which has at least one bore hole running through the contact carrier to the contact surface having the saucer-shaped recess, and the soldering material is poured into the bore holes of the contact carrier so that, after the melting, due to gravity and capillary action, the soldering material presses into the gap along the saucer-shaped recess, including into the circumferential annular gap.
For these process techniques, the solder can be placed into the bore holes of the contact carrier in the form, for example, of wire. In addition, these bore holes make possible an improved degasification of the space between the contact piece and contact carrier.
In a further embodiment of the method, it is proposed that a contact piece may be used that has a planar, saucer-shaped recess, into which the contact carrier at its mounting end is set, and a contact carrier be used, which, at its contact surface adjoining the saucer-shaped recess, has at least one recess, and the soldering material be poured into the recess of the contact carrier, so that, after the melting, the soldering material penetrates, due to gravity and capillary action, into the gap along the saucer-shaped recess, including into the peripheral annular gap.
In all of these cases, during the soldering, an oversupply of soldering material rises up again through the vertical gaps and bore holes, so that an optimal wetting and dosing of the soldering material is possible.
A further example of a method according to the present invention provides setting a contact piece into a saucer-shaped recess of a contact carrier and applying the soldering material in the form of a soldering paste onto the contact piece and over the annular gap end between the contact carrier and contact piece, so that, after the melting, the soldering material is pulled by gravity and capillary action into the gap along the saucer-shaped recess.
Here, too, it is possible to fix the contact piece on the contact carrier without a positive-locking or frictional connection. This variant is designed especially for securing contacts in the non-hanging position. As a solder paste, it is preferred to use one having a silver or copper base, the binding agent or binders evaporating during the heating-up process in a vacuum, leaving no residue. During the time when the soldering material is in a molten liquid state in a vacuum, the contact piece is held by the surface tension of the soldering material and/or the latter's adhesive force, so that precise positioning is also assured.
To achieve a good contact soldering and sufficient stability of the bond between contact piece and contact carrier, it is proposed that an amount of soldering material be used such that, after the complete wetting of the gap between contact carrier and contact piece, the remaining molten mass of solder is used to seal the solder supply points, for example, as a residual plug seals the solder supply points.
Thus the method according to the present invention makes it possible to satisfactorily manufacture soldered connections between contact pieces and contact carriers even in a hanging arrangement, the method being particularly advantageous when applied in connection with vacuum switching tubes. The method according to the, present invention can be refined and applied in that the contact arrangement composed of contact carrier, contact piece, and soldering material is preassembled into a unit having further components constituting the vacuum switching tube, components that are bonded to each other at soldering points using soldering material, along with a second contact arrangement, a shielding part, cover parts, insulating parts, and a bellows, and the preassembled unit being placed into a vacuum soldering oven, one of the two contact arrangements being in the hanging position of the contact piece and, under the influence of the vacuum, the simultaneous melting of all of the soldering material being effected at all of the soldering locations by heat, so that all of the soldered connections of the vacuum switching tube are produced in one process step.
According to the present invention, therefore, the soldering points of a piece to be connected, i.e., specifically, of the contact piece having a contact carrier, can be produced both in the hanging position as well as in the standing position. Since the soldering material penetrates into the gap between contact piece and contact carrier only after melting, there is no falling away due to excessive solder melting, which is the case when the soldering material is arranged beforehand between contact carrier and contact piece. For carrying out the method according to the present invention, at least for the soldered connection to be generated in the hanging position, a mechanical, clamping bond or mechanical positive-locking fit is sufficient to avoid a falling away of the contact piece from the contact carrier during the production of the soldered connection.
In order to prevent a not-yet-soldered contact piece from falling away from the contact carrier during a soldering process in the hanging position, the proposal is made to provide for a mechanical and/or friction-locking and/or form-locking bond at least in areas between the contact piece in the contact carrier by configuring them appropriately outside of the contact surfaces of contact piece and contact carrier forming the planar gap, the bond being produced in the assembly of contact piece and contact carrier. A mechanical bond of this type between contact piece and contact carrier can be provided, for example, through creating a profiling at least in areas on the lateral surface of the contact carrier and/or, if appropriate, also on the interior-side lateral surface of the recess of the contact piece, to achieve a light clamping of the contact carrier in a saucer-shaped recess of the contact piece for sufficient stability in the hanging position. This profiling, for example, can be provided as milled knobs or knurls having fins and depressions, or also, for example, by only a single profiling in the shape of a protruding rise on the lateral surface of the contact carrier.
In the assembly of the contact carrier and contact piece, instead of achieving a mechanically stable bond for a hanging position using a skeleton form, a flanging, or profiling, the contact pieces and contact carriers to be bonded to each other can also be joined using a friction- and positive-locking bond, such as in a bayonet lock. The minimal annular gap remaining in this context can be supplied, for example, from a soldering material supply—deposit—on the contact carrier using sufficient solder, for example using a corresponding piece of soldering wire.
The projections or grooves of a bayonet lock of this type can be shaped so as to taper into a slight cone, so that by twisting the contact piece in a contact carrier made of soft copper, a clamping screw connection is achieved having a good supporting capacity. In this context, it is possible to achieve a good, planar, and friction-locking bond between the contact piece and the contact carrier. At the same time, the groove of the bayonet lock bond can function as the solder supply channel and then as the soldered connection point for the two parts to be bonded subsequently, using solder.
The contact carriers and the contact pieces, in accordance with the application purpose and the load of the vacuum switching tube, can be made from known materials, such as were described in the documents mentioned above regarding the related art.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is explained in further detail below in exemplary embodiments with reference to the drawings, in which:
FIGS. 1 a and 1 b show a schematic depiction of the contact soldering of a contact piece to a contact carrier using a soldering disk in accordance with the related art, before (FIG. 1 a ) and after (FIG. 1 b ) the soldering process;
FIGS. 2 a and 2 b show a schematic depiction of the contact soldering of contact carrier and contact piece using soldering material disposed on the outside of the contact arrangement, before (FIG. 2 a ) and after (FIG. 2 b ) the soldering process;
FIGS. 3 a and 3 b show a schematic depiction of a contact soldering of contact piece to contact carrier using soldering material fed through the contact carrier, before (FIG. 3 a ) and after (FIG. 3 b ) the soldering process;
FIGS. 4 a and 4 b show a variant of the method shown in FIG. 3 a and 3 b;
FIG. 5 shows a variant of the method shown in FIG. 4 a;
FIG. 6 shows a contact soldering for bonding a contact piece to the contact carrier using soldering paste, in a schematic depiction in the standing position;
FIG. 7 shows a schematic cross-section of the vacuum switching tube after a completed contact soldering;
FIGS. 8 a , 8 b , and 8 c show a contact arrangement having a contact carrier FIG. ( 8 a ) and a contact piece (FIG. 8 b ), as well as a top view of the contact piece having a bayonet lock (FIG. 8 c ).
DETAILED DESCRIPTION
In FIG. 7, by way of example, a vacuum switching tube is depicted in schematic form having two contact arrangements, of which first contact arrangement 2 , 20 is fixedly arranged on the housing and second contact arrangement 1 , 10 is positioned in the housing so as to be movable by a bellows 7 . If a soldered connection between contact carrier 1 and contact piece 10 or contact carrier 2 and contact piece 20 cannot be produced in the standing position, i.e., the contact piece is placed onto the contact carrier from above, the problem arises to devise a more reliable method for producing the soldered connection of the contact arrangement in the hanging arrangement of the contact piece. For this purpose, as a rule, according to the related art, an effective positive locking and/or frictional locking is necessary, so that in response to melting the soldering material located, as in FIGS. 1 a , 1 b , between the contact surfaces to be bonded, contact piece 10 does not float or slide. If, as a consequence of the saucer-shaped recess 101 , see FIGS. 1 a , 1 b , the lateral overlap of contact piece 10 is used for the positive locking and frictional locking, then no soldered connection can form in this lateral area since no molten solder, or an insufficient amount, penetrates here.
According to the proposal of the present invention, see FIGS. 2 a and 2 b , between the parts to be bonded to each other, namely contact piece 10 and contact carrier 1 , first a sufficient positive-locking or mechanically supportive connection is produced, for example by configuring the contact piece so as to have a saucer-shaped recess 101 , into which is fitted the contact carrier at its mounting end, which can be correspondingly shaped. However, it is particularly advantageous to provide for a profiling 105 at least in areas on the lateral surface of the contact carrier and/or the single-sided lateral surface of the contact piece, to achieve a light clamping effect of the contact carrier in saucer-shaped recess 101 of the contact piece for a sufficient stability in the hanging position. The profiling can be shaped, for example, as milled knobs 105 having fins and depressions. Thus an adequate positive-locking bond between contact piece 10 and contact carrier 1 is created, a contact gap between the two parts remaining along saucer-shaped recess 101 , which is composed of annular gap RS, running to the outside, and planar gap FS. At the exterior circumference of the contact arrangement, where the contact gap between contact piece 10 and contact carrier 1 ends, soldering material 11 , for example in an annular shape as soldering wire, is placed on the edge of contact piece 10 adjacent to contact carrier 1 . Contact carrier 1 , prepared in this manner, contact piece 10 , which is pressed down, and soldering material 11 , placed externally, are heated in a vacuum in a vacuum chamber, so that soldering material 11 melts and penetrates into gap RS between contact piece 10 and contact carrier 1 and, consequently, it is pulled into gap FS between the contact surfaces, leading to the complete or near complete, wetting by molten solder of the contact surface between contact carrier and contact piece. At the same time, solder also remains, down to the upper external edge of contact piece 10 , and there forms a remaining plug 11 a , sealing the gap to the outside, resembling a hollow channel made of soldering material. Using the method according to the present invention, it is possible also to fill the vertical gaps at the side between contact piece 10 and the contact carrier using molten solder and thus to produce a significantly improved, strengthened bond between the parts. The bonding surface wetted by soldering material is designated as 30 .
In the variant in FIGS. 3 a and 3 b , provision is also made at first for a light positive locking between contact piece 10 and contact carrier 1 , i.e., without a soldering foil in between or, for example, a profiling, as in FIGS. 2 a and b . For this purpose, contact piece 10 is configured, for example, using a saucer-shaped recess 101 , into which contact carrier 1 is set. The mechanical bond produced in this manner by frictional locking and/or positive locking is sufficient to prevent contact piece 10 in the hanging position from falling out before and during the production of the soldered connection. Contact carrier 1 itself has at least one, as in FIG. 4 a , or, for example, two, as in FIG. 3 a , bore holes 102 , 103 running in the axial direction parallel to the axis, the bore holes functioning to receive soldering material 11 , for example, in the form of soldering wire. Bore holes 102 , 103 penetrate to the contact surface at the contact piece. After the parts, preassembled in this manner, are placed into a vacuum chamber, in a vacuum, and heat is applied, soldering material 11 melts and, due to gravity and capillary action, penetrates into the gap formed between the contact surfaces of contact piece 10 and contact carrier 1 along saucer-shaped recess 101 , and fills up the gap, also ascending at the lateral edges up to the upper edge, as in FIGS. 3 b and 4 b . The contact surface between contact carrier and contact piece is completely and adequately wetted in turn by the soldering material, and at the same time the bond between contact carrier and contact piece is strengthened by the rising soldering material at the external vertical gaps between contact piece and contact carrier. The quantity of solder is measured such that a residue of soldering material remains in the shape of a hollow channel 11 a at the foot of bore holes 102 , 103 , sealing them. In the event that bore holes 102 , as in FIG. 4 a , lead directly to the outside, they also function for improved degasification of the space between contact piece and contact carrier. To produce bond 30 between contact carrier 1 and contact piece 10 , a relatively small quantity of solder is necessary in the application of the method according to the present invention.
In FIG. 5, a further possible configuration of the preceding arrangement of soldering material is depicted partially outside the contact surfaces between contact carrier and contact piece to be bonded to each other in the contact soldering, contact carrier 1 having a recess 104 at its side facing contact piece 10 , the recess receiving the soldering material. Here, as well, the contact arrangement, preassembled as depicted in FIG. 5, is placed into a vacuum chamber, and there, in a vacuum, soldering material 11 is brought to the melting point through the application of heat, as a result of which it penetrates into the adjoining gaps between contact piece 10 and contact carrier 1 and, in accordance with the supply of solder, also rises into the lateral vertical gaps, thus producing the desired stable bond.
For standing arrangements of the contact soldering of a contact piece 20 to a contact carrier 2 , an arrangement in accordance with FIG. 6 is proposed, in which contact piece is also placed directly into a recess 21 on the upper side of contact carrier 2 . In this manner, a positive-locking grip is already provided. The soldering material, however, is not placed into the gap between contact piece 20 and contact carrier 2 , but rather on top, for example, as soldering paste 11 in a layer. During the heating procedure in a vacuum, the binding agent and binders of the soldering paste evaporate and the soldering material in a molten state can penetrate into the contact gap between contact carrier 2 and contact piece 20 along recess 21 and thus produce the desired contact soldering in this area.
In FIGS. 8 a and b , the contact arrangement is depicted having a contact carrier 1 in the form of a moving conductor and a contact piece 10 having a cup-shaped recess 101 , which is configured for a mechanical bond in the form of a bayonet lock. In FIG. 8 c , the top view of contact piece 10 having recess 101 and two lugs 107 protruding to the inside are depicted, which are shaped so as to protrude on the cylindrical interior side of recess 101 . Contact carrier 1 on the lateral surface in the area coming into contact with contact piece 10 has oppositely oriented grooves 106 arranged so as to run slightly diagonally, into which contact piece 10 having its lugs 107 can be introduced in a screw-like fashion. Via a short rotation, contact piece 10 is then firmly pressed onto contact carrier 1 . The remaining gap can then also be filled using solder, as is explained in FIGS. 2 a and 2 b , or also using solders from a solder repository, as is depicted, for example, in FIGS. 3 a , 4 a , 5 , and the soldered connection is produced.
The bayonet lock between contact piece and contact carrier can also have two or more beveled grooves and protuberances situated on the periphery, the grooves being able to be configured either on the contact carrier or on the contact piece, and the lugs then on the respective other part. For further improving the fixing of the contact piece on the contact carrier using a bayonet lock, the groove/grooves can also be given a slightly conical shape, i.e., tapering at the end, so that during the rotation of the parts to be joined with each other, a firm, gripping screw connection is achieved in the contact carrier made of a soft copper. In addition, n contact carrier can also be used as a solder supply channel and also forms a good solder connection area between the contact carrier and contact piece.
In FIG. 7, a vacuum switching tube is schematically depicted having a fixedly arranged contact carrier 2 , and having a contact piece 20 fixedly joined via a soldered connection 31 , as well as having a contact arrangement, movable in the axial direction of the arrow, including contact carrier 1 and contact piece 10 , fixedly joined via the soldered connection 30 , for example, as in FIG. 2 b . The housing is composed of pot-like cover parts 5 and 6 , an insulator 8 being arranged in between. The one pot-like cover is soldered to stationary contact carrier 2 in the area of connecting surfaces 32 —soldering points. Other pot-like cover 6 is secured at movable contact carrier 1 , specifically via two soldering points 34 , 36 , a bellows 7 being connected in between. Pot-like covers 6 , 5 are also connected to the insulator via soldering points 35 , 33 . On the interior side of contact pieces 10 , 20 , shielding part 4 having getter ring 3 is arranged for shielding the metal vapor arc, retaining the radiation heat, and dissipating the latter in the covers, as well as for sufficiently shielding the insulator from condensing metal vapor.
Using the method according to the present invention for the possibility of the contact soldering of contact piece 10 to the contact carrier in the latter's hanging position, as is explained in FIGS. 3 a through 5 , it is possible to reassemble the vacuum tube depicted in FIG. 7 and its components, to arrange the corresponding soldering material in the area of the contact gap of contact piece 10 and contact carrier 1 as well as at all connection points to be soldered 31 , 32 , 33 , 34 , 35 , 36 , and then to place the assembly, preassembled in this manner, into a vacuum soldering oven, and there, in a vacuum, through the application of heat, to produce all of the soldering connections in one working cycle—an oven cycle. | A method for manufacturing a contract arrangement for a vacuum switching tube having a contact carrier and a contact piece joined to the contact carrier in a vacuum using soldering material. The contact carrier is made of electrically highly conductive material, for example, copper, and the contact piece is made of a flame-resistant sintering material containing copper. The contact piece is pressed flat directly onto the contact carrier, generating a gap along the contact surface, and the soldering material is arranged on areas directly bordering the gap of the contact surface between the contact piece and the contact carrier. Subsequently, in a vacuum through the application of heat, the soldering material is brought to the melting point, and the molten soldering material penetrates into the gap of the contact surfaces between the contact carrier and the contact piece. | 7 |
This is a continuation of co-pending application Ser. No. 517,691, filed Oct. 24, 1974, which is a continuation of co-pending application Ser. No. 386,693, filed Aug. 8, 1973, which is a continuation of co-pending application Ser. No. 191,023, filed Oct. 20, 1971, all of which are, in turn, now abandoned.
BACKGROUND OF THE INVENTION
Heretofore in order to vacuum clean a surface in a dry state, to provide for steam cleaning of surfaces or to dye or tint surfaces, separate machines were utilized with the consequent expense and storage and maintenance problems. Such machines performed only separate tasks and were used individually, separate and apart from each other.
It is an object of the present invention to provide one unit which will vacuum wet as well as dry materials, will provide for steam cleaning and for dyeing or tinting surfaces as, for example, textile or fabric surfaces while at the same time extracting and reclaiming all excess liquid in the form of water or as a dye or tint.
It is a further object of the present invention to provide a cleaning device which will vacuum dry materials such as dirt, ashes, sawdust, as well as wet materials, without any change in the filtering system.
It is still another object of the present invention to provide a cleaning device having an attachment that may be used by hand manipulation for cleaning small or hard to reach areas.
The foregoing objects and others are set forth in the following detailed description of the invention. It is to be understood that this description and the drawings are for exemplary purposes and are not intended to in any way limit the invention as shown by the scope of the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
The apparatus of the invention will be more clearly explained by reference to the attached drawings in which
FIG. 1 represents a perspective view of the apparatus taken slightly from the above showing the lid storage of the hand tools;
FIG. 2 is a cross-sectional view of the apparatus, showing the relative positioning of the various components;
FIG. 3 is an end cross-section of the machine taken along the line A--A of FIG. 2;
FIG. 4 is an end cross-section taken along the line B-B of FIG. 2; and
FIG. 5 is a view of one embodiment of a wand or hand tool which may be used for the multipurpose operations of the device.
Turning now to the drawings, reference numeral 10 indicates generally the cabinet for the machine which has a cabinet 12 equipped with a hinged lid 14. Four universally swivelled wheels, two of which are shown at 16 and 18, support the cabinet. The lid 14 is adapted for storage of the hand operated attachments, represented by wand 20.
Reference numeral 22 indicates, generally, the vacuum section of the device and 24 the steaming and/or dyeing section.
Cabinet 12 is divided into an upper, or tank section 26 and a lower, or works section 28 by a divider 30, which is fitted into the sides of cabinet 12.
The vacuum section of the machine comprises a vacuum tank 32 and a vacuum pump or motor 34 having an air inlet port 36 and an outlet 38. Inlet 36 extends through the side of cabinet 12 and is equipped at the outer end thereof with a female receptacle which is adapted to receive in air-tight relation a male portion 40 fitted with flexible hose 42. The inner portion of inlet member 36 has a downwardly extending nozzle to deflect incoming air in the direction shown by the arrows.
Vacuum tank 32 is connected to the vacuum motor 34 by means of a standpipe 44 having an opening in the top and bottom thereof. A baffle 48 spaced from the bottom of the tank is situated on the standpipe 44 near to the top of such standpipe and extends across the length and width of the tank and prevents overflow of material or dirt entering the standpipe 44.
As will be more clearly explained as the description proceeds, the vacuum section of the machine is designed for routine cleaning, i.e., simple dust pick-up and the like, and also to pick up moisture from a steaming and/or dyeing operation. Standpipe 44, baffle 48 and filter 46 are designed into the equipment to assure that extraneous matter is prevented from entraining in the air-stream to the vacuum motor.
The steaming and/or dyeing section of the apparatus of the invention comprises generally, a liquid storage vessel or tank 50, a liquid circulating motor pump 52, and a heat exchanger 54. The liquid storage tank 50, which is affixed to and rests upon divider 30, is equipped with a filtered outlet 56 and an inlet 58. Pump 52 when activated by switching means, not shown, circulates liquid from tank 50 through outlet orifice 56, piping 60 and piping 62 to heat exchanger 54. In this electrically powered heat exchanger some of the liquid is converted to steam, when the device is switched to the steaming cycle, and is delivered through pipe 64 and female connector 66.
In order to utilize the machine of this invention when cleaning, steaming, or dyeing corner areas or along borders of an area, a wand or hand-held attachment 20 is provided, as shown in FIG. 5. When not in use the wand is maintained in position under the cover of the machine as shown in FIG. 1. The wand has a nozzle 80 adapted to be inserted into pipe 81 which leads to the vacuum tank 32. When the switch is activated for vacuum cleaning, the cleaning is accomplished through the orifice at 82 and the dirt passes into the vacuum tank through tube 83. When the switch is activated for directing steam or dye to the desired area of a rug, drape, fabric, or the like, the steam or dyeing liquid passes through the flexible tube 68 into the connection 85 and around through pipeline 86 out the orifice 87. As a consequence the hand-held attachment or wand 20 has in one compact unit both the means for accomplishing a vacuum cleaning operation and the steam for a dyeing operation.
In the event that a liquid from tank 50 such as a dye solution, for example, instead of water vapor or steam is required for the operation being carried out, heat exchanger 54 is cut out of the electrical circuit, or reduced to a level which is below the boiling temperature of water and a liquid is delivered by pump 52 through pipe 64, coupling 66 and 70 and flexible hose 68. A valve mechanism, indicated at 72 regulates the amount of liquid delivered to flexible hose 68 for application to the desired area. Excess liquid, and unconverted water during a steaming operation, is recycled by means of pump 52 and line 74 to tank 50.
As another feature of the unique combination of this invention the air outlet 38 from motor or vacuum pump 34 is arranged so that prior to exhaust through the associated cabinet exit 38a (FIG. 2) the flow of cooling air is over and around pump 52, an arrangement which is very beneficial as to the longevity of operation of the pump 52.
The device of the invention is electrically operated throughout, that is vacuum motor 34, water pump 52 and heat exchanger 54 are electrically powered. The usual electrical connections and switching combinations are provided such that these elements may be operated singly or in any combination. The electrical circuitry required to accomplish this is well known in the art and forms no part of the invention.
The versatility and flexibility of the apparatus of the invention is thus obvious from the foregoing description. For example, a vacuuming or cleaning operation is accomplished by connecting the flexible hose 42 from the wand to coupler 40, 36 and powering vacuum motor 34. If a steam cleaning operation is desired, either before or after a vacuum cleaning, flexible hose 68 and connector 70 are coupled to connector 66, heat exchanger 54 is energized and circulating pump 52 is again activated and any condensed steam is picked up and deposited in vacuum tank 32 where baffle 48 and standpipe 40 prevents its entrainment with the air stream to vacuum motor 34. When a solution of a detergent or a dye is placed in tank 50, the proper quantity at the desired temperature is delivered to the wand by means of flexible hose 68, coupler 70-66, pipe 64, heat exchanger 54, pipe 62, motor 52, pipe 60 and inlet 56. Again actuation of the vacuum unit permits the operator to pick up the excess suds or dye which is deposited in the liquid section of tank 32, as was explained above.
Thus it will be seen that this invention provides a unique combination of elements which is highly flexible and versatile and which includes a vacuuming operation, a steaming operation and a dyeing operation in one portable compact unit. | A cleaning apparatus providing in one unit, a vacuum cleaner for cleaning wet as well as dry surfaces, and a liquid reservoir with means for converting the liquid into steam. Means are also provided for applying steam to a surface while reclaiming excess deposits of steam into the unit through the vacuum system. The application and reclamation system may also be utilized to dye or tint surfaces. | 3 |
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 10/349,351, filed Jan. 22, 2003 now U.S. Pat. No. 6,872,841, which in turn is a continuation of U.S. patent application Ser. No. 10/177,147, filed Jun. 21, 2002, now issued as U.S. Pat. No. 6,566,393, the disclosures of all of which are incorporated by reference herein in their entirety.
STATEMENT OF GOVERNMENT SUPPORT
This invention was made with government support under NIH grant CA 17625-24. The Government has certain rights to this invention.
FIELD OF THE INVENTION
The present invention concerns water-soluble etoposide or podophyllotoxin analogs such as 4-beta-[(4″-benzamido)-amino]-4′-demethyl-epipodophyllotoxins and their 4′-ester derivatives, pharmaceutical formulations containing the same, and the use thereof to treat cancer.
BACKGROUND OF THE INVENTION
Etoposide (1) and Teniposide (2) are semisynthetic glucosidic cyclic acetals of podophyllotoxin (3) currently used in the chemotherapy for various types of cancer
(Jardine. (1980) Anticancer Agents Based on Natural Products Models ; Academic Press: New York, p. 319, Issell. (1982) Cancer Chemother. Pharmacol . 7:73). Another epipodophyllotoxin derivative, GL-331, has been developed and tested in phase II clinical trials against various cancers (Lee et al. (1995) Food and Drug Analysis . 3:209). Interestingly, although podophyllotoxin inhibits the assembly of microtubules, the primary action mode of its 4β-congeners, the epipodophyllotoxins, is to inhibit the catalytic activity of topoisomerase II by stabilizing the covalent topoisomerase II-DNA cleavable complex, cause DNA strands breaking and eventually lead to cell death (Osheroff et al. (1991) BioEssays 13:269, Alton & Harris (1993) Br. J. Haematol . 85:241–245, Cho et al. (1996) J. Med. Chem . 39:1383–1395, MacDonald et al. (1991) DNA Topoisomerase in Cancer ; Oxford University Press: New York, p. 119).
Major problems associated with etoposide and teniposide include acquired drug-resistance and poor water-solubility. U.S. Pat. No. 6,566,393 to Lee et al. describes unique etoposide analogs such as 4-beta-[(4″-benzamido)-amino]-4′-demethyl-epipodophyllotoxins to potentially overcome the drug-resistance problem. There remains a need for new etoposide analogs with anticancer and antitumor activity and more importantly, with improved water-solubility.
SUMMARY OF THE INVENTION
A first aspect of the present invention is a compound according to Formula I:
wherein:
X is a linking group selected from the group consisting of —O—, —S—, —NH—, —CO—, —CH═N—, or CH 2 NH—, and in one preferred embodiment is —NH—;
R 1 is a covalent linkage between X and Y, or is loweralkyl, loweralkenyl, or phenyl, and when phenyl is unsubstituted or is substituted from one to four times with loweralkyl, hydroxy, alkoxyl, alkylogen, or alkylamino, alkyoxycarbonyl, amino, halogen, nitro, or nitrile, and in one preferred embodiment R 1 is phenyl;
Y is none, —NHCO—, —CONH—, —OCO—, or —COO—;
Z is —(CH 2 ) n R 3 , where n is 0 to 8, and in which —(CH 2 ) n — may be incorporated in Z as a five-, six-, seven-, or eight-membered rings, for example:
where the material in brackets represents group Y, and R 3 is a loweralkyl, loweralkenyl, aryl, lower alkylamino, lower alkenylamino, or arylamino;
R 2 is —OR 4 , —NR 4 R 5 , —OCOR 4 , —OCOOR 4 , —OCOSR 4 , or —OCONR 4 R 5 , where R 4 and R 5 are selected from lower alkylamino, lower alkenylamino, or arylamino;
or a pharmaceutically acceptable salt thereof.
A further aspect of the present invention is a pharmaceutical formulation comprising a compound as described above in a pharmaceutically acceptable carrier (e.g., an aqueous carrier).
A still further aspect of the present invention is a method of treating a cancer, comprising administering to a human or animal subject in need thereof a treatment effective amount (e.g., an amount effective to treat, slow the progression of, etc.) of a compound as described above. Examples of cancers that may be treated include, but are not limited to, skin cancer, lung cancer including small cell lung cancer and non-small cell lung cancer, testicular cancer, lymphoma, leukemia, Kaposi's sarcoma, esophageal cancer, stomach cancer, colon cancer, breast cancer, endometrial cancer, ovarian cancer, central nervous system cancer, liver cancer and prostate cancer.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully hereinafter. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety.
The term “alkyl” or “loweralkyl” as used herein refers to C1 to C4, C6 or C8 alkyl, which may be linear or branched and saturated or unsaturated.
“Cycloalkyl” is specified as such herein, and is typically C3, C4 or C5 to C6 or C8 cycloalkyl.
“Alkenyl” or “loweralkenyl” as used herein likewise refers to C1 to C4 alkenyl, and alkoxy or loweralkoxy as used herein likewise refers to C1 to C4 alkoxy.
“Alkoxy” as used herein refers to linear or branched, saturated or unsaturated oxo-hydrocarbon chains, including for example methoxy, ethoxy, propoxy, isopropoxy, butoxy, and t-butoxy.
“Alkylogen” as used herein means alkyl or loweralkyl in which one, two, three or more (e.g., all) hydrogens thereon have been replaced with halo. Examples of alkylogen include but are not limited to trifluoromethyl, chloromethyl, 2-chloroethyl, 2-bromoethyl, and 2-iodoethyl. Alkylogens may also be referred to as haloalkyl or perhaloalkyl (e.g. fluoroalkyl; perfluoroalkyl).
The term “aryl” as used herein refers to C3 to C10 cyclic aromatic groups such as phenyl, naphthyl, and the like, and includes substituted aryl groups such as tolyl.
“Halo” as used herein refers to any halogen group, such as chloro, fluoro, bromo, or iodo.
The term “hydroxyalkyl” as used herein refers to C1 to C4 linear or branched hydroxy-substituted alkyl, i.e., —CH 2 OH, —(CH 2 ) 2 OH, etc.
The term “aminoalkyl” as used herein refers to C1 to C4 linear or branched amino-substituted alkyl, wherein the term “amino” refers to the group NR′R″, wherein R′ and R″ are independently selected from H or lower alkyl as defined above, i.e., —NH 2 , —NHCH 3 , —N(CH 3 ) 2 , etc.
The term “oxyalkyl” as used herein refers to C1 to C4 oxygen-substituted alkyl, i.e., —OCH 3 , and the term “oxyaryl” as used herein refers to C3 to C10 oxygen-substituted cyclic aromatic groups.
The term “alkylenedioxy” refers to a group of the general formula —OR′O—, —OR′OR′—, or —R′OR′OR′— where each R′ is independently alkyl.
“Treat” or “treating” as used herein refers to any type of treatment that imparts a benefit to a patient afflicted with a disease, including improvement in the condition of the patient (e.g., in one or more symptoms), delay in the progression of the disease, prevention or delay of the onset of the disease, etc.
“Pharmaceutically acceptable” as used herein means that the compound or composition is suitable for administration to a subject to achieve the treatments described herein, without unduly deleterious side effects in light of the severity of the disease and necessity of the treatment.
“Inhibit” as used herein means that a potential effect is partially or completely eliminated.
The present invention is concerned primarily with the treatment of human subjects, but may also be employed for the treatment of other animal subjects (i.e., mammals such as dogs, cats, horses, etc. or avians) for veterinary purposes. Mammals are preferred, with humans being particularly preferred.
A. Active Compounds.
Active compounds of the present invention may be produced by the procedures described herein or variations thereof which will be apparent to those skilled in the art. Novel methods useful for producing active compounds included herein are also an aspect of the present invention.
U.S. Pat. No. 6,566,393 to Lee et al. describes the general synthetic methods for C4 side chain extension and synthetic methods for C4′ side chain addition are described below is as follows:
Compounds of Formula I as noted above can be produced in the manner described above, or modifications thereof which will be apparent to those skilled in the art. Particularly preferred embodiments of the present invention are: (i) compounds of Formula IIa:
wherein:
X is a linking group selected from the group consisting of —O—, —S—, —NH—, —CO—, —CH═N—, and CH 2 NH—;
R 1 is a covalent linkage between X and Y, or is loweralkyl, loweralkenyl, or phenyl, and when phenyl is unsubstituted or is substituted from one to four times with loweralkyl, hydroxy, alkoxyl, alkylogen, alkylamino, alkyoxycarbonyl, amino, halogen, nitro, or nitrile;
Y is none, —NHCO—, —CONH—, —OCO—, or —COO—;
Z is —CHR 2 (CH 2 ) n R 3 , where n is 0 to 8, or —(CH 2 ) n — is incorporated into Z as a five-, six-, seven-, or eight-membered ring; R 2 is H, and R 3 is a loweralkyl, loweralkenyl, aryl, lower alkylamino, lower alkenylamino, or arylamino;
or a pharmaceutically acceptable salt thereof; or
(ii) compounds of Formula IIb:
wherein:
X is a linking group selected from the group consisting of —O—, —S—, —NH—, —CO—, —CH═N—, or CH 2 NH—, and in one preferred embodiment is —NH—;
R 1 is a covalent linkage between X and Z, or is loweralkyl, loweralkenyl, or phenyl, and when phenyl is unsubstituted or is substituted from one to four times with loweralkyl, hydroxy, alkoxyl, alkylogen, alkylamino, alkyoxycarbonyl, amino, halogen, nitro, or nitrile;
Y is none, —NHCO—, —CONH—, —OCO—, or —COO—;
Z is —(CH 2 ) n R 3 , where n is 0 to 8, or —(CH 2 ) n — is incorporated into Z as a five-, six-, seven-, or eight-membered ring,. R 3 is a loweralkyl, loweralkenyl, aryl, lower alkylamino, lower alkenylamino, or arylamino;
R 12 is —OR 4 , —NR 4 R 5 , —OCOR 4 , —OCOOR 4 , —OCOSR 4 , or —OCONR 4 R 5 , where R 4 and R 5 are selected from the group consisting of lower alkylamino, lower alkenylamino, and arylamino;
or a pharmaceutically acceptable salt thereof.
Note that an important feature of compounds of Formula IIa above is that, in substituent Z, R 2 is H. Note that an important feature of compounds of Formula IIb above is the group R 12 at the c4′ position. In both compounds of Formula IIa and IIb, R 1 is preferably phenyl, X is preferably —NH—, and Y is prefereably —CONH—. R 12 is preferably —OCOCH 2 N(CH 3 ) 2 .
Examples of active compounds of the present invention that can be produced by the procedures described above include, but are not limited to:
4′-O-Demethyl-4β-[4″(tyramido)-anilino]-4-desoxy-podophyllotoxin
4′-O-Demethyl-4β-[4″-(phenylethylamido)-anilino]-4-desoxy-podophyllotoxin
4′-O-Demethyl-4β-{[4″-(2′″-dimethylamino)-ethylamido]-anilino}-4-desoxy-podophyllotoxin
4′-O-Demethyl-4β-{[4″-(4′″-methyl-piperazyl)-amido]-anilino}-4-desoxy-podophyllotoxin
4′-O-Demethyl-4β-{[4″-(4′″-piperidinopiperidyl)-amido]-anilino}-4-desoxy-podophyllotoxin
4′-O-Demethyl-4β-{[4″-N-(4′″-amino-1′″-benzylpiperidine)-amido]-anilino}-4-desoxy-podophyllotoxin
4′-O-Demethyl-4β-{[4″-(4′″-nitrophenyl-piperazyl)-amido]-anilino}-4-desoxy-podophyllotoxin
4′-O-Demethyl-4β-{[4″-N-(3′″-aminoquinuclidine)-amido]-anilino}-4-desoxy-podophyllotoxin
4′-O-Demethyl-4′-(N′,N′-dimethyl-glycyl)-4β-(4″-fluoroanilino)-4-desoxy-podophyllotoxin
4′-O-Demethyl-4′-[(2′″-dimethylamino)-ethoxyl]-4β-(4″-fluoroanilino)-4-desoxy-podophyllotoxin
4′-O-Demethyl-4′-[(2′″-dimethylamino)-ethylamino]-4β-(4″-fluoroanilino)-4-desoxy-podophyllotoxin
B. Formulations and Pharmaceutically Acceptable Salts.
The term “active agent” as used herein, includes the pharmaceutically acceptable salts of the compound. Pharmaceutically acceptable salts are salts that retain the desired biological activity of the parent compound and do not impart undesired toxicological effects. Examples of such salts are (a) acid addition salts formed with inorganic acids, for example hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid and the like; and salts formed with organic acids such as, for example, acetic acid, oxalic acid, tartaric acid, succinic acid, maleic acid, fumaric acid, gluconic acid, citric acid, malic acid, ascorbic acid, benzoic acid, tannic acid, palmitic acid, alginic acid, polyglutamic acid, naphthalenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid, naphthalenedisulfonic acid, polygalacturonic acid, and the like; and (b) salts formed from elemental anions such as chlorine, bromine, and iodine.
Active agents used to prepare compositions for the present invention may alternatively be in the form of a pharmaceutically acceptable free base of active agent. Because the free base of the compound is less soluble than the salt, free base compositions are employed to provide more sustained release of active agent to the target area. Active agent present in the target area which has not gone into solution is not available to induce a physiological response, but serves as a depot of bioavailable drug which gradually goes into solution.
The compounds of the present invention are useful as pharmaceutically active agents and may be utilized in bulk form. More preferably, however, these compounds are formulated into pharmaceutical formulations for administration. Any of a number of suitable pharmaceutical formulations may be utilized as a vehicle for the administration of the compounds of the present invention.
The compounds of the present invention may be formulated for administration for the treatment of a variety of conditions. In the manufacture of a pharmaceutical formulation according to the invention, the compounds of the present invention and the physiologically acceptable salts thereof, or the acid derivatives of either (hereinafter referred to as the “active compound”) are typically admixed with, inter alia, an acceptable carrier. The carrier must, of course, be acceptable in the sense of being compatible with any other ingredients in the formulation and must not be deleterious to the patient. The carrier may be a solid or a liquid, or both, and is preferably formulated with the compound as a unit-dose formulation, for example, a tablet, which may contain from 0.5% to 95% by weight of the active compound. One or more of each of the active compounds may be incorporated in the formulations of the invention, which may be prepared by any of the well-known techniques of pharmacy consisting essentially of admixing the components, optionally including one or more accessory ingredients.
The formulations of the invention include those suitable for oral, rectal, topical, buccal (e.g., sub-lingual), parenteral (e.g., subcutaneous, intramuscular, intradermal, or intravenous) and transdermal administration, although the most suitable route in any given case will depend on the nature and severity of the condition being treated and on the nature of the particular active compound which is being used.
Formulations suitable for oral administration may be presented in discrete units, such as capsules, cachets, lozenges, or tablets, each containing a predetermined amount of the active compound; as a powder or granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water or water-in-oil emulsion. Such formulations may be prepared by any suitable method of pharmacy which includes the step of bringing into association the active compound and a suitable carrier (which may contain one or more accessory ingredients as noted above).
In general, the formulations of the invention are prepared by uniformly and intimately admixing the active compound with a liquid or finely divided solid carrier, or both, and then, if necessary, shaping the resulting mixture. For example, a tablet may be prepared by compressing or molding a powder or granules containing the active compound, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing, in a suitable machine, the compound in a free-flowing form, such as a powder or granules optionally mixed with a binder, lubricant, inert diluent, and/or surface active/dispersing agent(s). Molded tablets may be made by molding, in a suitable machine, the powdered compound moistened with an inert liquid binder.
Formulations suitable for buccal (sub-lingual) administration include lozenges comprising the active compound in a flavoured base, usually sucrose and acacia or tragacanth; and pastilles comprising the compound in an inert base such as gelatin and glycerin or sucrose and acacia.
Formulations of the present invention suitable for parenteral administration conveniently comprise sterile aqueous preparations of the active compound, which preparations are preferably isotonic with the blood of the intended recipient. These preparations may be administered by means of subcutaneous, intravenous, intramuscular, or intradermal injection. Such preparations may conveniently be prepared by admixing the compound with water or a glycine buffer and rendering the resulting solution sterile and isotonic with the blood.
Formulations suitable for rectal administration are preferably presented as unit dose suppositories. These may be prepared by admixing the active compound with one or more conventional solid carriers, for example, cocoa butter, and then shaping the resulting mixture.
Formulations suitable for topical application to the skin preferably take the form of an ointment, cream, lotion, paste, gel, spray, aerosol, or oil. Carriers which may be used include vaseline, lanoline, polyethylene glycols, alcohols, transdermal enhancers, and combinations of two or more thereof.
Formulations suitable for transdermal administration may be presented as discrete patches adapted to remain in intimate contact with the epidermis of the recipient for a prolonged period of time. Formulations suitable for transdermal administration may also be delivered by iontophoresis (see, for example, Pharmaceutical Research 3:318 (1986)) and typically take the form of an optionally buffered aqueous solution of the active compound. Suitable formulations comprise citrate or bis\tris buffer (pH 6) or ethanol/water and contain from 0.01 to 0.2M active ingredient.
C. Methods of Use.
In addition to the compounds of the formulas described herein, the present invention also provides useful therapeutic methods. For example, the present invention provides a method of inducing cytotoxicity against tumor cells, or treating a cancer or tumor in a subject in need thereof.
Cancer cells which may be inhibited include cells from skin cancer, small cell lung cancer, non-small cell lung cancer, testicular cancer, lymphoma, leukemia, Kaposi's sarcoma, esophageal cancer, stomach cancer, colon cancer, breast cancer, endometrial cancer, ovarian cancer, central nervous system cancer, liver cancer and prostate cancer.
Subjects which may be treated using the methods of the present invention are typically human subjects although the methods of the present invention may be useful for veterinary purposes with other subjects, particularly mammalian subjects including, but not limited to, horses, cows, dogs, rabbits, fowl, sheep, and the like. As noted above, the present invention provides pharmaceutical formulations comprising the compounds of formulae described herein, or pharmaceutically acceptable salts thereof, in pharmaceutically acceptable carriers for any suitable route of administration, including but not limited to oral, rectal, topical, buccal, parenteral, intramuscular, intradermal, intravenous, and transdermal administration.
The therapeutically effective dosage of any specific compound will vary somewhat from compound to compound, patient to patient, and will depend upon the condition of the patient and the route of delivery. As a general proposition, a dosage from about 0.1 to about 50 mg/kg will have therapeutic efficacy, with still higher dosages potentially being employed for oral and/or aerosol administration. Toxicity concerns at the higher level may restrict intravenous dosages to a lower level such as up to about 10 mg/kg, all weights being calculated based upon the weight of the active base, including the cases where a salt is employed. Typically a dosage from about 0.5 mg/kg to about 5 mg/kg will be employed for intravenous or intramuscular administration. A dosage from about 10 mg/kg to about 50 mg/kg may be employed for oral administration.
The present invention is explained in greater detail in the following non-limiting examples.
EXAMPLE 1
Experimental. The compounds 5–6 were synthesized from podophyllotoxin (3) as outlined in Scheme 1 according to previous published methods. 4′-demethyl-epipodophyllotoxin (DMEP) was synthesized from podophyllotoxin stereoselectively using the methanesulphonic acid/sodium iodide reagents (Kamal et al. (2000) Bioorg. Med. Chem. Lett . 10:2059) followed by nucleophilic substitution with water. This intermediate was subjected to nucleophilic displacement by 4-amino benzoic acid to afford intermediate 7. Compounds 5 and 6 were synthesized from condensation of 7 with the corresponding amines by employing reagents dicyclohexylcarbodiimide (DCC) and 4-(dimethylamino) pyridine (DMAP).
The compounds 9–14 were synthesized from 4β-arylamino-podophyllotoxin derivatives with simple esterification in the presence of DCC and DMAP.
All melting points were taken on Fisher-Johns and Mel-Temp II melting point instruments and are uncorrected. IR spectra were recorded on a Perkin-Elmer 1320 spectrophotometer. 1 H NMR spectra were obtained using Bruker AC-300 and WM 250 NMR spectrometers with TMS as the internal standard. All chemical shifts are reported in ppm. FABMS and HRFABMS spectral analyses were determined on a JOEL HX-110 instrument. Analytical thin-layer chromatography (TLC) was carried out on Merck precoated aluminum silica gel sheets (Kieselgel 60 F-254). Optical rotations were measured with a JASCO DIP-1000 polarimeter. All target compounds were characterized by 1 H and IR spectral analyses and MS analyses.
EXAMPLE 2
General Preparation of 4′-demethyl-desoxypodophyllotoxins (5–6). To a solution of 7 (0.1 mmol) in tetrahydrofuran (3 ml) was added dicyclohexylcarbodiimide (DCC, 22 mg, 0.11 mmol). After 15 minutes, an appropriate amine (0.1 mmol) was added to the reaction mixture and the mixture was stirred at ambient temperature overnight. The suspension was diluted with 10 ml EtOAc and was filtered. After the solvent was removed under reduced pressure, the crude product was chromatographed on the FlahElute system using a 12M silica cartridge and the elute solvent: EtOAc:hexanes 1:1.
4′-O-Demethyl-4β-[4″(tyramido)-anilino]-4-desoxy-podophyllotoxin (5): yield 82%; mp 173–175° C.; [α] 25 D −103.0 (c=0.1, acetone); IR (film) 1767 (lactone), 1695 (amide), 1470, 1448, 1382 (aromatic C═C), 1122 (phenol) cm −1 ; MS m/e: 638 [M] + ; 1 H NMR (acetone-d 6 ) δ 7.72 (d, J=8.7 Hz, 2 H, 3″, 5″-H), 7.07 (d, J=8.7 Hz, 2 H, 2′″, 6′″H), 6.84 (s, 1 H, 5-H), 6.78 (d, J=8.7 Hz, 2 H, 2″, 6″-H), 6.76 (d, J=8.7 Hz, 2 H, 3′″, 5′″-H), 6.54 (s, 1 H, 8-H), 6.39 (s, 2 H, 2′, 6′-H), 5.98 (dd, J=2.4, 0.9 Hz, 2H, —OCH 2 O—), 5.06 (m, 1 H, 1-H), 4.60 (d, J=4.5 Hz, 1H, 4-H), 4.40 (t, J=7.8 Hz, 1H, 11-H), 3.85 (t, J=7.8 Hz, 1 H, 11-H), 3.70 (s, 6 H, 3′, 5′-OCH 3 ), 3.50 (m, 2 H, —NH—CH 2 —), 3.26 (m, 2 H, 2, 3-H), 2.79 (t, J=7.8 Hz, 2 H, —CH 2 —Ph—). Anal. (C 36 H 34 N 2 O 9 .2.1/4 H 2 O) C, H, N.
4′-O-Demethyl-4β-[4″-(phenylethylamido)-anilino]-4-desoxy-podophyllotoxin (6): yield 84%; mp 166–167° C.; [α] 25 D −96.0 (c=0.1, acetone); IR (film) 1732 (lactone), 1463 (aromatic C═C), 1120 (phenol) MS m/e: 621 [M−1] + ; 1 H NMR (CDCl 3 ) δ 7.50 (d, J=8.4 Hz, 2 H, 3″, 5″-H), 7.25–7.12 (m, 5 H, 2′″-6′″H), 6.67 (s, 1H, 5-H), 6.44 (d, J=8.4 Hz, 2 H, 2″, 6″-H), 6.41 (s, 1 H, 8-H), 6.23 (s, 2H, 2′, 6′-H), 5.84 (dd, J=11.4, 0.9 Hz, 2 H, —OCH 2 O—), 4.65 (d, J=3.3 Hz, 1 H, 1-H), 4.45 (d, J=4.2 Hz, 1 H, 4-H), 4.22 (t, J=7.5 Hz, 1 H, 11-H), 3.78 (t, J=3.9 Hz, 1 H, 11-H), 3.65 (s, 6 H, 3′, 5′-OCH 3 ), 3.55 (m, 2 H, —NH—CH 2 —), 3.08–2.90 (m, 2H, 2, 3-H), 2.82 (t, J=6.9 Hz, 2 H, —CH 2 —Ph). Anal. (C 36 H 34 N 2 O 8 .2 H 2 O) C, H, N.
General Preparation of 4′-demethyl-desoxypodophyllotoxins (8–14). To a solution of appropriate arylamino-podophyllotoxin derivatives (0.2 mmol) in dichloromethane (10 ml) were added DCC (62 mg, 0.3 mmol), DMAP (24 mg, 0.2 mmol) and the corresponding carbonylic acids (0.3 mmol). The reaction mixture was stirred under nitrogen at room temperature for 24 h. Then, the suspension was filtered, concentrated, and purified with the FlashElute system using EtOAc:hexanes:Et 3 N as eluant. The hydrochloride salts were obtained by treating the amines with 4.0 N hydrogen chloride in dioxane. Primary and secondary amines were afforded by deprotection with p-TsOH in CH 2 Cl 2 .
4′-O-Demethyl-4′-(N′,N′-dimethyl-glycyl)-4β-(4″-nitroanilino)-4-desoxy-podophyllotoxin (8): yield 90%; mp 179–180° C.; [α] 25 D −252.0 (c=0.05, acetone); IR (film) 1740 (lactone) 1719 (ester) 1455, 1369, 1365 (aromatic C═C) cm −1 ; MS m/e: 605 [M−1] + ; 1 H NMR (CDCl 3 ) δ 8.11 (d, J=9.3 Hz, 2 H, 3″, 5″-H), 6.74 (s, 1 H, 5-H), 6.56 (d, J=9.0 Hz, 2 H, 2″, 6″-H), 6.53 (s, 1 H, 8-H), 6.32 (s, 2 H, 2′, 6′-H), 5.95 (dd, J=4.8, 1.5 Hz, 2 H, —OCH 2 O—), 4.79 (m, 1 H, 1-H), 4.68 (d, J=4.8 Hz, 1H, 4-H), 4.38 (m, 1 H, 11-H), 3.79 (m, 1 H, 11-H), 3.67 (s, 6 H, 3′, 5′-OCH 3 ), 3.45 (s, 2 H, —CO—CH 2 —), 2.41 (s, 6 H, —N(CH 3 ) 2 ).
4′-O-Demethyl-4′-(N′,N′-dimethyl-glycyl)-4β-(4″-fluoroanilino)-4-desoxy-podophyllotoxin (9): yield % 84%; mp 127–129° C.; [α] 25 D −101.0 (c=0.1, acetone); IR (film) 1742 (lactone) 1376, 1365 (aromatic C═C) cm −1 ; MS m/e: 577 [M−1] + ; 1 H NMR (acetone-d 6 ) δ 6.94 (dd, J=8.7, 8.7 Hz, 2 H, 3″, 5″-H), 6.82 (s, 1 H, 5-H), 6.75 (dd, J=9.0, 4.5 Hz, 2 H, 2″, 6″-H), 6.55 (s, 1 H, 8-H), 6.47 (s, 2 H, 2′, 6′-H), 5.97 (dd, J=6.9, 1.0 Hz, 2 H, —OCH 2 O—), 4.91 (m, 1 H, 1-H), 4.64 (d, J=4.8 Hz, 1 H, 4-H), 4.42 (t, J=7.2 Hz, 1 H, 11-H), 3.92 (t, J=7.2 Hz, 1 H, 11-H), 3.68 (s, 6 H, 3′, 5′-OCH 3 ), 3.39 (s, 2 H, —CO—CH 2 —), 3.32 (m, 1 H, 2-H), 3.18 (m, 1 H, 3-H), 2.35 (s, 6 H, —N(CH 3 ) 2 ).
4′-O-Demethyl-4′-(N′,N′-dimethyl-glycyl)-4β-(4″-nitroanilino)-4-desoxy-podophyllotoxin hydrochloride (10): yield 92%; mp 201–202° C.; [α] 25 D −118.0 (c=0.2, acetone); IR (film) 1740 (lactone) 1369, 1365 (aromatic C═C) cm −1 ; 1 H NMR (CD 3 OD) δ 8.11 (d, J=9.3 Hz, 2 H, 3″, 5″-H), 6.77 (s, 1 H, 5-H), 6.72 (d, J=9.3 Hz, 2 H, 2″, 6″-H), 6.54 (s, 1 H, 8-H), 6.46 (s, 2 H, 2′, 6′-H), 5.94 (d, J=4.5 Hz, 2 H, —OCH 2 O—), 4.89 (m, 1 H, 1-H), 4.68 (d, J=4.8 Hz, 1 H, 4-H), 4.36 (m, 1 H, 11-H), 3.74 (m, 1 H, 11-H), 3.71 (s, 2 H, —CO—CH 2 —), 3.66 (s, 6 H, 3′, 5′-OCH 3 ), 3.29 (m, 2H, 2, 3-H), 2.92 (s, 6 H, —N(CH 3 ) 2 ).
4′-O-Demethyl-4′-(N′,N′-dimethyl-glycyl)-4β-(4″-fluoroanilino)-4-desoxy-podophyllotoxin hydrochloride (11): yield 97%; mp 162–163° C.; [α] 25 D −117.0 (c=0.05, acetone); IR (film) 1738 (lactone) 1373, 1365 (aromatic C═C) cm −1 ; 1 H NMR (CD 3 OD) δ 6.83 (dd, J=8.7, 8.7 Hz, 2 H, 3″, 5″-H), 6.68 (s, 1 H, 5-H), 6.58 (dd, J=9.0, 4.5 Hz, 2 H, 2″, 6″-H), 6.44 (s, 1 H, 8-H), 6.40 (s, 2 H, 2′, 6′-H), 5.86 (d, J=7.8 Hz, 2 H, —OCH 2 O—), 4.72 (m, 1 H, 1-H), 4.63 (d, J=4.8 Hz, 1 H, 4-H), 4.35 (t, J=7.2 Hz, 1 H, 11-H), 3.88 (t, J=7.2 Hz, 1 H, 11-H), 3.65 (s, 6 H, 3′, 5′-OCH 3 ), 3.59 (s, 2H, —CO—CH 2 —), 3.30 (m, 2 H, 2, 3-H), 2.98 (s, 6 H, —N(CH 3 ) 2 ).
4′-O-Demethyl-4′-glycyl-4β-(4″-fluoroanilino)-4-desoxy-podophyllotoxin (13): yield % 25% (from NPF); mp 133–135° C.; [α] 25 D −69.0 (c=0.1, acetone); IR (film) 1740 (lactone) 1378, 1365 (aromatic C═C) cm −1 ; MS m/e: 549 [M−1] + ; 1 H NMR (CD 3 OD) δ 6.89 (dd, J=8.7, 8.7 Hz, 2 H, 3″, 5″-H), 6.75 (s, 1 H, 5-H), 6.63 (dd, J=9.0, 4.5 Hz, 2 H, 2″, 6″-H), 6.51 (s, 1 H, 8-H), 6.44 (s, 2 H, 2′, 6′-H), 5.92 (d, J=4.5 Hz, 2 H, —OCH 2 O—), 4.67 (m, 1 H, 1-H), 4.53 (d, J=4.5 Hz, 1 H, 4-H), 4.41 (m, 1 H, 11-H), 3.90 (m, 1 H, 11-H), 3.69 (s, 6 H, 3′, 5′-OCH 3 ), 3.30 (s, 2 H, —CO—CH 2 —), 3.28 (m, 1 H, 2-H), 3.08 (m, 1 H, 3-H).
4′-O-Demethyl-4′-sarcrosyl-4β-(4″-fluoroanilino)-4-desoxy-podophyllotoxin (14): yield % 38% (from NPF); mp 138–139° C.; [α] 25 D −104.0 (c=0.2, acetone); IR (film) 1734 (lactone) 1457, 1365 (aromatic C═C) cm −1 ; MS m/e: 563 [M−1] + ; 1 H NMR (CD 3 OD) δ 6.90 (dd, J=8.7, 8.7 Hz, 2 H, 3″, 5″-H), 6.73 (s, 1 H, 5-H), 6.63 (dd, J=8.7, 4.5 Hz, 2 H, 2″, 6″-H), 6.48 (s, 1 H, 8-H), 6.35 (s, 2 H, 2′, 6′-H), 5.92 (dd, J=4.5, 1.5 Hz, 2 H, —OCH 2 O—), 4.75 (d, J=4.2 Hz, 1 H, 1-H), 4.56 (d, J=4.8 Hz, 1 H, 4-H), 4.39 (t, J=7.2 Hz, 1 H, 11-H), 3.90 (t, J=7.2 Hz, 1 H, 11-H), 3.70 (s, 6 H, 3′, 5′-OCH 3 ), 3.31 (s, 2 H, —CO—CH 2 —), 3.16 (m, 1 H, 2-H), 3.09 (m, 1 H, 3-H), 2.43 (s, 3H, —NH(CH 3 )).
EXAMPLE 3
Biological Assay and Results. The compounds 5–6, 8–14 were evaluated for their inhibition against KB and 1-resistant KB-7d cells and ability to induce cellular protein-linked DNA breaks (PLDB) (Table 1). Most compounds effectively inhibited the KB cell growth, and more notably, retained the inhibition against the 1-resistant KB-7d cells.
TABLE 1
Induction of protein-linked DNA breaks and inhibition of tumor cells by 5–6 and 8–14.
KB
KB-7d
% PLDB
ED 50 b
ED 50 b
Comp.
R
R′
formation a
(μg/ml)
(μg/ml)
1
H
100
0.5
>10
4
H
228
0.33
2
5
H
275
0.025
0.8
6
H
227
0.035
0.5
8
219
0.4
8
9
165
0.4
8.0
10
156
2
10
11
102
0.9
10
12
161
0.2
2
13
199
0.35
10
14
172
1
9
a % PLDB formation was determined by the SDS/potassium precipitation method. Percentage values were levels of protein-linked DNA breaks induced by drug treatment relative to the VP-16 control set arbitrarily at 100%. The values reflected effects at the concentration of 5 μg/ml.
b ED 50 was the concentration of drug that afforded 50% reduction in cell number after a 3-day incubation.
The foregoing is illustrative of the present invention, and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein. | Etoposide analogs with improved water-solubility such as 4′-O-Demethyl-4′-(N′,N′-dimethyl-glycyl)-4β-(4″-nitroanilino)-4-desoxy-podophyllotoxin (8) and 4′-O-Demethyl-4′-(N′,N′-dimethyl-glycyl)-4β-(4″-fluoroanilino)-4-desoxy-podophyllotoxin (9) are described, along with pharmaceutical formulations containing the same, methods of use thereof, and intermediates and methods of making the same. | 2 |
This application claims the benefit of U.S. Provisional Application No. 60/186,185, filed Mar. 01, 2000 U.S. Provisional Application No. 60/159,465, filed Oct. 13, 1999. This application is a continuation-in-part of U.S. application Ser. No. 09/071,523, filed May 01, 1998, U.S. Pat. 6,276,700 B1, issued Aug. 21, 2001, which application claims the benefit of U.S. Provisional Application No. 60/045,490 filed May 02, 1997.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention most generally relates to gravity driven vehicles such as downhill racing carts. More particularly this invention relates to maneuverable, steerable gravity driven vehicles Most particularly, the invention relates to a stable, durable gravity driven vehicle which is steerable, has at least two wheels or two skis or a combination of wheels and skis and at least one brake, is ridden in a prone, face down, face forward position and which may be ridden on varied surface terrain such as dirt, grass or snow. Even more particularly this invention relates to the mechanism for suspension of the wheels and/or skis which is configured to provide precise control in turns especially the carving of turns, by the skis, while descending on snow cover.
2. Description of Related Art
Although there are various patents disclosing embodiments for devices which permit movement over a surface, the following patents known to the inventors hereof, do not in any manner suggest or teach the Gravity Driven Steerable Wheeled or ski equipped Vehicle disclosed and claimed by applicants in the instant application for patent.
U.S. Pat. No. 3,887,210 to Funke discloses a four wheeled, downhill racing cart with a steel frame and a driver's seat mounted on the frame for use on various surfaces. The rider of the cart must sit in an upright position with feet forward. The cart is steered by applying pressure with the feet to pedals attached to the front axle assembly. There is a braking mechanism which is triggered by leaning forward in the seat and engaging a braking member which is suspended from the seat frame. When the seat is leaned forward and the braking member is engaged, a plate is lowered to contact the ground surface and apply braking by frictionous contact with the ground. A rubber pad is fastened to the underside of the braking plate for braking engagement with the surface over which the cart is traveling. The cart does have handle bars, however, they are not used at all for steering control of the vehicle. The handles appear to be used for holding on and keeping the rider with the cart. The device also has carry hooks on the front handle assembly for towing of the device to the starting area. Additionally, the device can be fitted with a “roll-bar” attachment.
U.S. Pat. No. 4,098,519 to Reid, Jr. device looks most like the known “flexible flyer” type of snow sled. This wheeled sled has four wheels and may be ridden on a variety of surfaces in a sitting or prone position. The body of the device is not inclined and is composed of several, separate, wooden slats. There are slots in the body of the device for gripping when riding in a seated position. However, the prone position would be preferred in order for the user to operate the two hand brakes installed on the handle bars at the front of the device. The device is steered by way of crossed steering bars pivoted to each of the rear axle brace, front axle brace, and steering handle. The steering bars are connected diagonally to opposite positions on the front and rear axles such that the axle braces are pivoted in opposite directions as the steering handle is moved—this minimizes turning radius. Springs return the steering handle to a neutral, centered position when there is no pressure on the steering handle. The hand brakes act on the front wheels. This device does not have any sort of tow hook for pulling the sled to a starting position. There is no restraining device or harness on this, or any of the previously described sleds. There is also no “roll-bar” or any sort of plate or device to prevent injury or to keep the sled from tipping over.
U.S. Pat. No. Des. 331,031 to Janoff discloses a design for a land sled. Design patents cover only the look of the device depicted in the Figures and no real description of the device is included in a design patent. This particular land sled differs from the two previously described devices in several ways. It has two large roller type wheels, instead of four smaller wheels. It is capable of being steered by either the hands or feet and can be ridden sitting in an upright position (steering with the feet) or in a prone position (steering with the hands). The steering appears to be accomplished in a way similar to that of known “flexible flyer” type snow sleds—by pushing and/or pulling the large handle bar extending across the front of the device. There are also slots along the side of the sled, towards the back, for gripping when using the sled from a seated position. There does not appear to be any sort of incline to the main body of the sled, on which one would sit or lay prone, although it is difficult to determine much about the mechanics of a device from a design patent.
U.S. Pat. No. 5,354,081 to Huffman et. al. discloses a stunt-riding toy for use on a variety of surfaces including snow. The device may be fitted with four wheels, or skis. This vehicle has a seat and also must be operated from a sitting position, with the feet placed on plates near the front of the device. The device is quite narrow and is steered mainly by leaning in the direction it is desired to turn. The front foot plates also serve as a brake and a means to keep the vehicle from leaning too far and tipping over. If the vehicle leans too far, the plates will contact the ground surface, apply braking pressure and prevent further tipping. The device has two handles and a rear hand cable brake which pulls a plate into contact with the wheels when the hand brake is engaged. The handles are positioned near the rear of the device, close to the seat so that the rider's arms hang down along the rider's side to grip the handles, and keep the rider in an upright position.
The invention has the particular objectives, features and advantages of: 1) a steerable gravity driven vehicle; 2) that such vehicle is ridden in a prone, face forward position; 3) that such vehicle has at least one brake; 4) that such vehicle has a plurality of wheels, most preferably four (4) wheels however the sled having three (3) wheels—the single wheel preferably located between the legs of the driver—is also disclosed and is within the scope of the disclosure of the invention; 5) that such vehicle may alternatively have a combination of skis and wheels providing for enhanced performance for use on snow covered terrain; 6) that such vehicle may alternatively have at least one ski forward or in the front position of the vehicle and a slide pan toward the rear portion of the vehicle; 7) that such vehicle may alternatively have at least 3 skis, wherein either one ski is forward or in the front position of the vehicle or toward the rear portion of the vehicle; 8) that such vehicle as described in 1) though 7) above may have incorporated therein the mechanism for suspension of the wheels and/or skis which is configured to provide precise control in turns especially the carving of turns, by the skis, while descending on snow cover; and 9) that such vehicle as described in 1) through 4) above may be retrofitted with components in order to create the vehicle(s) described in 5), 6), 7) and 8) above.
The patents noted herein provide considerable information regarding the developments that have taken place in this field of non-motorized vehicle technology. Clearly the instant invention provides many advantages over the prior art inventions noted above. Again it is noted that none of the prior art meets the objects of the gravity driven vehicle in a manner like that of the instant invention. None of them is as effective and as efficient as the instant Gravity Driven Steerable Vehicle for maneuvering down steep, varied surface terrain and none of them are operated from the prone face down and face forward position.
SUMMARY OF THE INVENTION
The most fundamental objects and advantages of the invention are: 1) a steerable gravity driven vehicle; 2) that such vehicle is ridden in a prone, face down, face forward position; 3) that such vehicle has at least one brake; 4) that such vehicle has at least two wheels or skis/slide pan or a combination thereof; 5) that such vehicle has a steering suspension mechanism which provides for the carving, by the steerable skis, of precise turns on snow covered surfaces: and 6) a kit of components which are used to retrofit a wheeled vehicle to one with wheels, skis, pan or a combination of wheels, skis or pan.
It should be noted that where there are three (3) wheels on the vehicle, the third wheel may be located either at the front or the rear of the vehicle. The third wheel may be the same size as the other two wheels, or may be large or smaller. The third wheel may be independently steerable, or steerable in cooperation with the steering of the other two wheels.
The vehicle may have independent mechanical, air actuated or hydraulic actuated brakes and may have independent hydraulic shock absorbers on some or all wheels. But the vehicle need not have shock absorbers at all, or may have shock absorption only for the front wheels, for example. The vehicle also may have an attachment for the picking up of the vehicle by, for example, a ski chair lift, and which may be a part of the driver/operator restraint system acting to keep the operator's legs from drifting off of the vehicle especially in a sharp turn maneuver. The attachment for picking up the vehicle may further serve to protect the rider should the vehicle roll over. However, this attachment is not fundamental to the invention.
A primary object of the invention is to provide a gravity driven steerable vehicle comprising a chassis and a riding surface on which a rider is oriented in a prone, face down, face forward position, at least two wheels or skis or combination thereof, means for steering the vehicle, means for causing deceleration or halting of motion of the vehicle, and means for harnessing the rider onto and into the vehicle.
Another primary object of the invention is to provide means for steering each wheel independently.
A further primary object of the invention is to provide means for absorbing shock exerted on said vehicle caused by the vehicle passing over rough terrain.
Another object of the invention is to provide means for towing the vehicle to the top of an incline, and means for assisting the rider in staying on the vehicle and protecting the rider if the vehicle were to roll over.
Yet another object of the invention is to provide such a vehicle further comprising four wheels.
Another object of the invention is to provide such a vehicle having three wheels.
A still further object is to provide a safety brake which actuates upon release of the hand grips for operation and parking safety if a rider were to fall off of the vehicle during operation of the vehicle.
A yet still further object is to provide a means for automatically causing the vehicle to hold a constant turn which actuates upon the occasion if a rider were to fall off of the vehicle during operation of the vehicle.
A fundamental object of this invention is to provide a means or mechanism for suspension of the wheels and/or skis which means or mechanism is comprises a single a-arm pivotably attached to an axle at an axle pivot point and a shock absorber connecting end pivotably connected to one end a shock absorber and which shock absorber other end pivotably connected to said axle. The suspension system may be provided preferably independent for each wheel or ski or on only the front axle of the vehicle. The suspension system configured to provide precise control in turns especially the carving of turns, by the skis, while descending on snow covered terrain.
Another fundamental object of the invention is to provide a ski assembly having front end and a ski rear end, a ski running surface and a ski upward-facing surface and having a ski brake assembly configured to cause, when said brake assembly is operator actuated, a brake blade to extend below said ski running surface at said ski rear end thereby engaging the terrain surface upon which the ski is running. There may also be provided a brake return assembly preferably using springs to return said brake blade to a non-braking position.
These and further objects of the present invention will become apparent to those skilled in the art after a study of the present disclosure of the invention and with reference to the accompanying drawings which are a part hereof, wherein like numerals refer to like parts throughout, and in which:
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a combination of a top plan view, a side plan view and a front plan view of the vehicle all of which are illustrating the body curvatures, the rider inclined riding surface/bed and the like;
FIG. 2 shows a top plan view of the vehicle, showing, in shadow the axle, steering, and wheel spindles;
FIG. 3 shows a top plan view of the three (3) wheeled embodiment of the vehicle;
FIG. 4 is a detail view of the assembly axle with an air/oil shock used in the wheel suspension;
FIG. 5 is a detail view of the assembly axle with a coil/oil shock used in the wheel suspension;
FIG. 6 is a detail view of the hydraulic rear wheel brake system;
FIG. 7 is a detail view showing the steering linkage in association with the prone steering position of the rider;
FIG. 8 is a detail view showing the right rear wheel spindle;
FIG. 9 is a detail view showing the right front wheel spindle;
FIG. 10 the two views illustrate detail of the tow-bar assembly which also is a part of the rider restraint system;
FIGS. 11A, 11 B and 11 C are a top plan view, and side plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a wheeled vehicle retrofitted with skis on the front and wheels to the rear;
FIGS. 12A, 12 B and 12 C are a top plan view, and side plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a wheeled vehicle retrofitted with skis on the front and skis on the rear;
FIGS. 13A, 13 B and 13 C are a top plan view, and side plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a wheeled vehicle retrofitted with skis on the front and a slide pan to the rear which slide pan has grooves directed from front to rear which provide lateral stabilizing of the vehicle and which has a suspension system and a piston actuator which actuates braking by pressing the shovel/blade into the snow surface;
FIGS. 14A and 14B is a combined and sectioned drawing of a top plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a braking system for a vehicle having wheels in the rear;
FIGS. 15A and 15B is a combined and sectioned drawing of a top plan view and a rear plan view respectively showing, in shadow, substantially all of the components and their relationship and which illustrates a braking system for a vehicle having wheels in the front;
FIGS. 16A and 16B is a top plan view and a rear plan view respectively which illustrates in the partial top plan view in shadow the front skis assembled to the front a-arm and also illustrating in shadow the steering linkage, the front brake system and the front suspension system and particularly in FIG. 16B is illustrated the “canting” of the skis;
FIG. 17 is a partial rear plan view of the attachment of a rear ski with brake components and showing, in shadow, the “unloaded” attitude of the ski and the relative positions of the suspension components and the fully loaded shock absorber compressed attitude of the ski and the relative positions of the suspension components;
FIG. 18 is a partial top plan view of the left rear ski attached to the rear axle illustrating the a-arm attachment to the ski post, the a-arm pivot point on the axle, the connection of the a-arm to the shock absorber which is attached to the axle at the shock absorber pivot location and also showing the brake blade, brake arm, brake cylinder;
FIG. 19 is a side plan view of the ski assembly of the invention, which shows, in shadow, the change in position of the brake components of the braking assembly; and
FIG. 19A is a top view of section AA which illustrates the detail of the brake return spring assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following is a description of the preferred embodiment of the invention. It is clear that there may be variations in the size and the shape of the gravity driven wheeled vehicle, in the materials used in the construction and in the orientation of the components. Most importantly, the teaching of the wheeled version of the gravity driven vehicle is applicable to the version having skis or pans mounted in place of some or all of the wheels and which is used as a gravity driven vehicle on snow or ice covered downhill terrain. The stability in the absorbing of shock from uneven surface conditions and the stability and performance while making turns while going downhill derives from the combination of the steering and suspension geometry and the inherent shape of the skis mounted in place of the wheels and tires.
A. The Wheeled Gravity Driven Vehicle:
In order to most simply and clearly characterize the essential features of the invention reference is made to drawing FIGS. 1, 1 A, 1 B, 2 , 3 , 6 and 10 in which the essential elements of the invention are identified by numerals (not in a circle). FIGS. 4, 5 , 7 , 8 and 9 are details of various elements which are well known to the ordinary skilled artisan.
It is also important to note that the instant vehicle invention may have one wheel in front and one wheel in the rear. It is also possible to have three wheels with the single wheel either in the front or in the rear of the vehicle. Steering may be effected by using either the front wheel(s) or the rear wheel(s) or both. Braking combinations are likewise possible—front wheel, rear wheel or both.
With reference now to particularly FIGS. 1, 2 , 3 , 6 , 10 , 14 A, 14 B, 15 A and 15 B there is illustrated a four wheeled gravity driven steerable wheeled vehicle 10 . There is a chassis 12 having chassis front portion 12 A, chassis rear portion 12 B, chassis underside 12 C and chassis top side 12 D. A rider riding surface 14 is on chassis top side 12 D and is configured to cause a rider on rider riding surface 14 to be oriented in a prone, face down, face forward position. There is provided a means for attaching, 16 , a rear axle assembly 16 A substantially at chassis rear portion 12 B. There is also means for mounting, 18 , a front axle assembly 18 A substantially at chassis front portion 12 A.
Provided also is a means for steering, 20 , gravity driven steerable wheeled vehicle 10 or three-wheeled vehicle 40 by the rider when the rider is positioned on rider riding surface 14 . There are rear wheel hub and spindle assemblies 22 integral with rear axle assembly 16 A. Wheels and tires 23 are normally mounted to the wheel hub. Front wheel hub and spindle assemblies 24 are integral with front axle assembly 18 A.
A braking system or means for causing deceleration and halting of motion 26 of vehicle 10 when vehicle 10 (or 40 ) has motion is provided. Braking system 26 may be hydraulic, mechanical or a combination of the two and braking may be of all wheels or some of the wheels.
In order to help the rider stay on vehicle 10 or 40 , there is a means for harnessing 28 the rider onto and into rider riding surface 14 when the rider is positioned on the vehicle. To provide additional comfort for the rider and to improve the stability of the vehicle while moving, there may be provided means for absorbing shock 20 exerted on each of the front wheels and tires 23 attached to each of the two front wheel hub and spindle assemblies 24 thereby damping shock caused by vehicle 10 passing over rough terrain, between front wheels and tires 23 and front axle assembly 18 A. There may also be means for absorbing shock 32 exerted on each of the rear wheels and tires 23 attached to each of the two rear wheel hub and spindle assemblies 22 thereby further damping shock.
In order to get wheeled vehicle 10 or 40 or ski equipped vehicle 10 A or 40 A up a ski slope for example, there is provided a combination rear roll bar and transport bail 34 . When the rider is on the vehicle, bar 34 is in the lowered position providing the rider with a roll bar and an object against which pressure may be applied when the rider is in a sharp turn. Bar 34 is placed in a second position which permits attachment to a lift such as a ski lift.
In order to discuss some of the engineering features, reference is again made to the drawings including FIGS. 4-19. The drawings show simply the preferred embodiments of the wheeled and the ski equipped vehicle which have the following preferred specifications:
FIG. 1 shows a top, side, and front plan view of the vehicle, illustrating the body curvatures, the rider inclined riding surface/bed including the 11″ diameter high speed pneumatic, tubeless tires in the preferred embodiment of the vehicle, which are designed for motor vehicle racing at speeds in excess of 100 mph and which provide excellent traction and a soft but firm ride.
Advanced four wheel “A” arm air spring, oil damped suspension—independent four wheel suspension with air/oil shocks or with coil/oil shocks is provided and yields a smooth, stable ride over surfaces with irregularities ranging from wash board to large bumps. However, not all four wheels need have suspension, possibly only the front wheels might have suspension. Also, the vehicle could be made in either a four-wheeled or three wheeled embodiment. In either embodiment, the suspension is not essential. FIG. 3 illustrates a three (3) wheeled embodiment of the vehicle. FIG. 4 shows a detail view of the assembly axle with an air/oil shock used in the wheel suspension, and FIG. 5 shows a detail view of the assembly axle with a coil/oil shock used in the wheel suspension.
Independent hydraulic braking is provided from dual, real wheel, hydraulic disk brakes, designed for motor vehicle racing at speeds to 150 mph and operated with a single hand lever. These brakes give smooth, uniform and powerful braking capability whether with a four or three-wheeled embodiment. The braking system could be modified for a three-wheeled embodiment. FIG. 6 is a detail view of the hydraulic rear wheel brake system.
For the detail of the braking system used with the ski equipped version of the vehicles 10 A or 40 A, reference is made to FIGS. 16-19. Particularly, FIGS. 16A and 16B illustrates in the partial top plan view in shadow front skis 70 A assembled to the front a-arm 32 A and also illustrating in shadow the steering linkage, the front brake system 80 including brake return system 88 and the front suspension system 30 and particularly in FIG. 16B is illustrated the “canting” of the skis 70 A;
FIG. 17 shows the attachment of a rear ski assembly 70 A i.e, the ski assembly having ski brake assembly 80 as a part of ski assembly 70 and also shows, in shadow, the “unloaded” attitude of ski assembly 70 A and the relative positions of the suspension components and the fully loaded shock absorber 32 B compressed attitude of the ski and the relative positions of the suspension components, i.e., a-arm 32 A and the piston of absorber 32 B;
FIG. 18 shows a left rear ski 70 A attached to means for absorbing shock 32 which is attached to the rear axle 31 , the manner of the a-arm 32 A attachment to the ski post 72 , the a-arm pivot point 32 A 3 on the axle 31 , the connection of the a-arm shock attachment end 32 A 2 to the shock absorber end 32 B 1 which shock absorber is attached to the axle at the shock absorber pivot location 32 B 2 and also showing the brake blade 84 , brake arm 82 , and the brake cylinder 81 . FIG. 19 is a view of the ski assembly 70 A of the invention, which shows, in shadow, the change in position of the brake components of the braking assembly 80 . FIG. 19A is a top view of section AA which illustrates the detail of the brake return spring assembly 88 along with return springs 88 A.
There is provided a combination rear roll bar and transport bail. This bar is hinged so that locked in the folded down position, it tends to confine the legs of the rider and further resists overturning of the vehicle. When this bar is in the unfolded or up position it is useful as a tow or lift bar which may be attachable to a ski lift as an example of use. However, it is possible to have an embodiment of the vehicle without this feature. FIG. 10 illustrates detail of the tow-bar assembly which also is a part of the rider restraint system.
The prone (lying down) low center of gravity design provides control and good visibility. It is also possible that this low position may add to the level of safety for the rider. The extremely low center of gravity provides a relatively stable and safe ride—overturning is nearly impossible.
There is provided a safety harness which enhances control, stability and rider safety, and which is shown illustrated in FIGS. 2 and 3. The shoulder harness provides rider stability and contributes to rider safety by keeping the rider in place on the vehicle.
There is also an automatic brake which actuates upon release of the hand grips for operation and parking safety. This feature is not essential to the basic embodiment of the invention, however this is an important additional feature. With this safety braking mechanism, the vehicle will be stopped if the rider were to fall off of the vehicle at some point during the operation of the vehicle. Additional to the automatic brake system there may also be a means for causing the vehicle to go into a constant tight turn mode of operation if the rider loses control or if the rider fall from the vehicle while in motion.
The surface of the vehicle on which the rider lays is comprised of a closed cell body pad for rider comfort. There is an elevated chest rest and thick foam mat which provide additional rider comfort and visibility.
In the preferred embodiment, the body and chassis of the vehicle is made from light weight foam core fiberglass reinforced construction. The strong, rigid, impact resistant foam filled fiberglass body with aluminum inserts provides a single framework for attachment of all components. Fiberglass body, plated steel parts, and extensive use of aluminum provide optimum protection from the elements, and from impact damage.
The steering and braking mechanism is a ball bearing bicycle style steering and braking assembly which is positive, responsive and familiar to all to control, thus making learning to ride, and riding the vehicle easier and more comfortable. FIGS. 7 and 15A provide, in combination a detail view showing the prone steering linkage. Substantially the same steering system as shown is FIGS. 7 and 15A is also used in the ski equipped vehicles as shown in FIGS. 11A, 12 A, 13 A and 16 A.
There are provided precision bearings on all four axles in one embodiment. Independent rear axles provide maximum maneuverability in a four wheeled embodiment. The vehicle may be provided with precision wheel hubs, with pre-lubricated ball bearings, which are maintenance free. In a preferred embodiment the suspension and steering spindle bearings are formed of woven TEFLON or NOMEX and are designed to withstand high impact forces and hostile environments, and provide long life with no maintenance. FIG. 2 shows a top, side, and front plan view of the vehicle showing, in shadow, the axle, steering, and wheel spindles. Also, FIGS. 8 and 9 show a detail view showing the right rear wheel spindle and a detail view showing the right front wheel spindle.
The preferred steering post ball bearings and linkage ball rod ends provide maintenance free, smooth, zero back lash response. Each vehicle may be provided with elastomer bumper strips in the front and the rear which provide impact protection for the vehicle and rider. The preferred steering post, wheel, and front and rear axle assemblies can be removed intact should maintenance be required, thus reducing time and cost of any necessary maintenance.
In a preferred embodiment, the vehicle chassis has a ramp-shaped underbody and detachable covers which offer protection for axles, steering linkage, and suspension from road obstacles. Each vehicle in the preferred embodiments has strong, impact resistant fiberglass fenders which protect the rider from track dirt and contact with the wheels or skis when riding.
Following is a general description of the many technical features and the advantages achieved by the presently disclosed invention. It is material provided to further enhance the level of disclosure and present all of the presently known advantages achieved because of the technical features of the invention.
General Discussion:
A. The Gravity Driven Vehicle with Skis or Combination of Skis and Wheels or Slide Pan
While much of the following description is presented as a description of a wheeled vehicle similar to the vehicle of the present invention as described above but which has been retrofitted or specially constructed to result in the vehicle for use on snow covered terrain. It is important to note that the vehicle basically as described above but modified for use on snow may be custom made rather than created from a wheeled version by means for retrofitting the wheeled version. All of the disclosure above is applicable to the disclosure of the ski version of the vehicle except of course that portion which relates to the specifics of the braking system and some aspects of the steering systems.
1. Retro Fit Kits/Ski Version
The retrofit kit is used in conjunction with the gravity driven wheeled vehicle of the present invention or other like products to make the product easily adaptable for use in snow covered conditions. The details of the systems described below apply as a retrofit package or basically describe the components and the function when applied to a gravity driven vehicle custom designed and dedicated for use only on snow. I.e., a wheeled vehicle may be retrofitted with the combination of skis or slide pans or custom designed and built in the same manner. FIGS. 11-13 and 16 illustrate the vehicle with skis in the front and wheels to the rear, skis both front and rear, and skis in front and a slide pan with braking to the rear respectively. It should further be noted that the use of skis and slide pan or slide pans is interchangeable in that they both provide the sliding surface upon which the vehicle rides when in descent on a snow covered surface. A slide pan or ski may be used in any combination in the front in the rear or both front and rear locations of the vehicle.
Front Steering System—FIGS. 11-13 and 16
A unique discovery during the course of the development efforts to create the winter or snow covered terrain version of the gravity driven vehicle occurred in the integration of the skis onto the existing single swing arm suspension design of the wheeled product. As a consequence of the advanced four wheel “A” arm air spring, oil damped suspension—independent four wheel suspension with air/oil shocks or with coil/oil shocks as illustrated in at least FIGS. 4, 5 , and the multiple views of FIGS. 11-16 there achieved a smooth, stable ride over surfaces with irregularities ranging from wash board to large bumps. With the mounting of skiis to the A-arm or the wishbone portion of the suspension system, the position or attitude of the outer edge of all skis due to the single arm geometry when there is no rider on the sled and the shocks are operating properly, causes the outer edge of all skis to be constantly engaged with the ground or snow surface. When the sled is being ridden the loading of the shocks, depending on how they are set, causes the skis to change to a more flat or level attitude relative to the snow or to the ground surface. This attitude only reaches a substantially flat attitude if there is extreme loading on the sled body and does so to absorb shock to the sled and rider. After such levels of loading and impulse types of shocks to the sled, the sled always returns to the outer edge engagement posture. Substantially because of this characteristic of ski attitude or the inward canting of the skis when the sled is being ridden, on a modest downhill terrain put in particular when travelling on steeper downhill and upon initiation of turns, the lower or downhill ski becomes more heavily loaded tending to increase the flatness orientation relative to the snow surface yet still resulting in the outer edge carving into the snow. I.e., the outer edge of the ski carves into the snow and as it becomes increasingly loaded the suspension slightly counters the digging or carving action but continues to engage the snow surface. The upper ski or uphill ski, particularly the outer edge, with the lesser loading while in the turn it is still partially canted inwardly, carves as well and even more aggressively because of this canted attitude of the uphill ski in the turn. Alternatively described, the uphill ski acts somewhat as an anchor as this engagement becomes more unloaded in an aggressive turn, the a-arm extends its full travel maintains constant engagement with the snow due to the fact the lower or downhill ski is flattening allowing the attitude of the uphill ski to remain in constant contact with the snow. This unexpected performance characteristic or functionality provides benefits such as for example: the carving action of both skis constantly counterbalancing each other provides tremendous control and maneuverability in virtually every snow condition; and under conditions of heavy loading of the downhill ski, the digging and tipping tendency of the sled is reduced dramatically. To provide further control and maneuverability a keel component may be added to the ski bottoms.
A. The front ski retrofit is attached to the existing front a-arm (wishbone) assembly of the wheeled version with either a double or the single arm/linkage geometry by utilizing the existing fastening system. When fixed to the suspension linkage the ski has the ability to pivot from an axis perpendicular to the axle allowing the tip and heal to pivot in opposition to one another, upwards and downwards and is limited in its pivot by a stop mechanisms mounted to either the ski or the mounting system. The width and length of the selected skis and the forward or rearward positioning of the pivot point is established based upon the terrain and the specific performance requirements desired. The steering geometry has been designed to create a carving action when the skis are turned by the steering linkage. I.e., upon causing a turn using the steering mechanism both ski tips rise slightly, the tails sink slightly and the inner edge of the ski opposite of the direction of the turn and the outer edge of the ski in the direction of the turn tilt slightly downwards into the snow or ice surfaces. These edges can also be described as the ski edges on the inner radius of the turn.
Brake System—FIGS. 13, 16 - 19
B. The independently or simultaneously actuated right and left, rear, front or rear and front, or independent rear and front combined brakes or single brake actuation unit whether one or divided mechanism is integrated in to the front ski and trailing or sliding pan or ski assemblies that are part of the vehicle/mountain sled retrofit package. The actuation of the mountain sled brake is either mechanical, hydraulic, servo-mechanical, pneumatic or a combination of these technologies. When this solution is used as a retrofit it is intended, whenever and wherever possible, that the existing actuation system or systems be utilized.
Rear Tracking and Control System—FIG. 13
C. The rear brake system or systems is/are integrated into an under body pan covering a portion or all of the sled under body from approximately the middle of the sled length and some distance forward of the rear axle location mounting surfaces and is attached or nearly meets the sled underside and extends sufficiently across the width of the sled in the front in a fixed or in a limited manner with a hinge or slide like interface allowing the pan from the hinge point rearwards to move up and down or to slide or flatten out across the under face of the sled a distance equal to the translated stroke distance of an internally mounted shock system. The pan will be a complete cover with a downward sloping straight or radiused lead edge, running from the mounted or hinged or meeting leading edge and transitioning to a gliding surface that runs almost parallel to the underside of the body or sled frame. The rear pan or ski assemblies will be covering a single or double shock absorption mechanism able to operate independent of or together with each other and the braking mechanism that will be substantially a swing arm or linearly actuated arm or blade that will when actuated protrude out from the pan or ski below their running surfaces and into the snow or ice surface at a positive, negative or right angle to the pan or running surface and will be depth adjustable equal to the geometry and stroke of the actuation. This pan or ski (if chosen) as seen from behind is profiled to provide maximum lateral grip and stability when either turning or gliding. The geometries are optimized to address snow condition and terrain.
Benefits
D. Commercial: The winter retrofit package allows an owner of a summer mountain sled the simplified and flexible solution of utilizing at a minimum a sled body with an integral frame or a sled body with a separate frame. Additionally, depending upon the components of the winter retrofit package, many more of the basic of summer mountain sled components can be used in retrofitting the summer sled for winter recreation such as the axle, suspension, steering and braking systems.
E. Technical: The retrofitted summer sled steering, braking, and rear tracking and control systems provide in the sled retrofitted for winter use all of the already known benefits of summer/wheeled sled including superior control and stability for a snow sledding experience.
2. Alternative Ski Version—Studded Tires
The condition of downhill ice packed or ice covered roadways, trails, paths, etc. presents a braking, steering and control challenge for both a conventional summer mountain sled and a winter mountain sled of any form or configuration. The operational challenge is to provide a sled with a steering and braking solution that handles these conditions. The following embodiment of the invention and declared benefits address this challenge.
A mountain sled equipped with four wheel or three wheel independent or simultaneous braking systems will have its standard tires replaced with slick or profiled tires that have been retrofitted or produced to order with studs, nails, screws, etc. fixed to, inserted into or imbedded in the rolling surface of the tire and protruding from the rolling face of the tire sufficiently to provide contact and grip in the existing ice or ice packed condition on the running surface. The selection of each tire profile and cleat material, cleat geometry and cleat placement and number of cleats is dependent solely on the application surface and can be changed and optimized accordingly to best suit the exact requirements of each downhill surface.
Benefits Alternative Ski Version—Studded Tire Version
This solution has the distinct benefit of providing exceptional control on most every downhill ice covered or ice packed roadway, trail, path, etc. running surface.
I. Due to the fact that only the tires used for summer sport are replaced with tires having studs or nails (or the like) mounted to the tread portion of the tire to provide improved friction interface between the sled and the running surface. All other subsystems, steering, suspension and braking remain the same for the studded tire version as for the summer tire version. The resulting sled has substantially all of the performance advantages of the summer wheeled vehicle.
I Double Arm Independent Suspension (Upper and Lower Control Arm Design)
The challenge of providing superior handling and control of a gravity driven mountain sled is to offer the best technology to achieve differing optimized operating results to meet the demands of the conditions and requirements of various terrains. The integration of certain solutions in a mountain sled with tires or with winter attachments such as in various presented solutions is primarily possible due to the combination of certain existing technologies, materials and compact componentry and by integrating them into various suspension geometries. The advent of small components coming from the mountain bike industry, has permitted mountain sledding to move from being basically unsophisticated toys to sophisticated sports equipment.
Integrated into the mountain sled is a suspension system that displays when viewed from the side (from sled rear to front or front to rear) a suspension geometry that is trapezoidal in form (parallelogram) with all four joints forming pivots and the two sled side, upper and lower fastening points/pivots are fixed in some manner firmly to the sled frame or uni-body or axle system or combination thereof and the spindle or the ski assembly or ski pan assembly is fixed somewhere on the fixed member connecting the outboard pivot points of the trapezoid. As part of this design and resisting loading of the trapezoidal design is an arm that extends at an angle away from one of the inboard trapezoid pivot locations and is an integral mechanical arm to which a shock absorber is attached to the end of arm and to a fixed point on the body, frame or axle system and both ends of the shock absorber can pivot. This geometry allows the upright mounting face for the spindle or ski or pan to move the spindle or ski or snow pan assembly upward and downward when the sled is pointed straight forward and when the sled itself has certain load exerted and released such that the tire, ski or pan maintains complete contact of its lower running surface with the operating surface, the running surface remains parallel with itself as it is loaded and unloaded. The longitudinal motion of the entire assembly is limited by the stroke of the shock absorber and the operating envelope of the related mechanics. This design permits minimal axial motion of the contact running surface as it is loaded and unloaded called scrubbing. This scrubbing action is considerably less than that witnessed by the solution already presented in the claim from TSI with a single arm solution.
Benefits
This solution gives the clear benefits of
II. Maintaining constant and maximum contact of the entire running face of the tire, ski, and pan solutions with the running surface.
III. Reduces scrubbing and non-uniform wear of the running surfaces of the tires, skis and pans.
IV. Simplifies steering geometry compound angles allowing maximization of ski contact and carving benefits. This system is highly recommended for applications utilizing skis and sliding pan systems.
II Integrated Body & Frame Solution
The body design and construction for the instant vehicle represents the latest form of taking the idea of monocoque or body integral frames and eliminating the need for conventional frames and separate bodies for use in mountain sled, sleds and sled product applications. This idea utilizes the fiberglass upper and lower body components known as or halves and sandwiches them together and imbeds inserts to add strength, to bond the halves, to stiffen the body and to take maximum advantage of the collective strength of each system. This solution accommodates and allows the fiberglass to be a connecting structure through the use of adhesives and epoxies that are part of the normal fiber-glassing process of dissimilar materials. This permits the combination of a variety of materials that would not otherwise be combined in a conventional fame/body construction. The imbedded materials then are optimized for their ability to retain fasteners, to choose material that accommodates extreme variations in temperature, adequately spread load across the fiberglass surface and eliminating extra material where it is unnecessary.
Benefits
The benefits from such a solution are;
I. Provides singular body and frame system, simplifying assembly, inventory and repair.
II. Makes maximum use of the strength and stiffness of each system.
III. Allow adaptability and design modifications when new materials come available without requiring the whole design be changed.
There are additional subsystems which may be incorporated into the gravity driven vehicle of each of the embodiments described such as for example:
Rollover protection
Steering damping
Accessories such as headlights, speedometer
Adjustable steering ratios
Prone sled body angle support system
Complete braking system i.e., one system for the front and one for the rear which may use two (2) independent master cylinders and brake circuits.
Detail Relative to the Suspension System, the Ski Assembly and The Braking System
Suspension geometry action and performance contribution to tracking and steering control: The existing, previously disclosed single A-arm suspension geometry provides the ability to present the outer edge of four skis, when mounted to a two opposing arm axle assemblies, to the snow at an angle to the running surface which delivers significant unique, maneuvering and steering control performance in most all snow conditions. This performance results from the fact that a carving geometry of the skis to the snow occurs. This engagement with the running surface is equally as consistent improves as the sled is underway and is caused to turn through the steering linkage. In a turn or as one is traversing a downhill slope the outboard or downhill ski receives increased load and the ski engages more with the snow/ice running surface until such time that the load on this ski begins to overcome the resisting force of the shock attached to the shock anchor point on the A-arm and the axle. As the resisting force (ajustable) is gradually overcome the A-arm begins to pivot at the A-arm pivot and ski assembly begins to move toward a flatter orientation with the snow. This action helps to avoid over powering the engagement of the downhill ski downhill edge and helping to avoid overturning. Simultaneously, the uphill ski is less loaded but still has its outer edge engaged in the snow and creates a scrapping action on the adjacent downhill snow/ice as well as packing what ever loose snow is present under the underside of the ski. This uphill ski performance improves as the downhill ski continues to flatten in respect to the running surface and loading. Additionally, the underside of any and all skis can be equipped with various geometry keels to assist in linear or turn tracking of all skis as they, under suspension applied compressive loads, present more ski surface and the keels to the running surface. There are always limits to this performance resulting from excessive speed and surface conditions, etc.
Ski Pivot Action and Performance Contribution:
The Ski foot and post pivot allows any ski when traveling over uneven surfaces to follow the terrain contour more closely. The swing motion allowed by this feature is limited by the presence of bumpers mounted on the ski foot which contact ski post extensions when pivot travel limits are reached. This function delivers another benefit because of the ability to allow the ski to follow the terrain more closely that being it causes the brake mounted on the attached ski assembly to achieve more consistent contact with running surface.
Braking Alternative A: Brake Action and Performance Contribution:
The brake assembly developed by the applicants provides superior braking action in various snow and ice conditions. The brake assembly has a hydraulic piston actuated lever equipped with a brake blade. This brake is actuated through the introduction of hydraulic pressure into the input port, the pressure causes the piston shaft to extend from the cylinder in the direction of the rear of the ski, the shaft is attached to the brake lever which begins to pivot at the brake lever pivot and rotates the lever with the attached blade toward the running surface until such point that the full stroke piston and the lever has been reached. The developed solution looked to achieve maximum force, with limited space by using a short stroke cylinder and applying multiple ratio motion at the brake tip. Currently, the solution developed provides practically two inches of travel at the brake tip. The solution utilizes external extension springs to assist the brake return when no longer under hydraulic pressure. The solution is further supported by the presence of an expansion tank mounted to and on the non-pressure side of the brake actuation cylinder. The expansion cylinder is partially filled with the same fluid used to actuate the piston and then securely plugged. This expansion tank provides three benefits, closed system that does not allow air to enter the non-pressurized side of the system and contaminate the pressurized side of the system if air were to get by the piston seals, this non-pressurized side of the system could be used to introduce opposing pressure by filling it with more fluid and when compared with an open ended system where an air vent is present to relieve pressure this solution eliminates the likelihood of drawing contaminants such as water into the cylinder or by the piston seals into the pressurized fluid side of the system.
Braking Alternative B: Brake Action and Performance Contribution:
The brake assembly developed by the applicants provides superior braking action in various snow and ice conditions. The brake assembly depicted in print number(s) ______ shows a hydraulic piston actuated lever equipped with a brake blade. This brake is actuated through the introduction of hydraulic pressure into the input port, the pressure causes the piston shaft to retract extend from the fully extended position away from the rear end of the ski, the shaft is attached to the brake lever which begins to pivot at the brake lever pivot and rotates the lever with the attached blade upwards away from and out of the running surface until such point that the full stroke piston and the lever has been fully retracted. The developed solution looked to achieve maximum force, with limited space by using a short stroke cylinder and applying multiple ratio motion at the brake tip. Currently, the solution developed provides practically two inches of travel at the brake tip. The solution utilizes external extension springs to assist the brake return when no longer under hydraulic pressure. The solution is further supported by the presence of an expansion tank mounted to and on the non-pressure side of the brake actuation cylinder. The expansion cylinder is partially filled with the same fluid used to actuate the piston and then securely plugged. This expansion tank provides three benefits, closed system that does not allow air to enter the non-pressurized side of the system and contaminate the pressurized side of the system if air were to get by the piston seals, this non-pressurized side of the system could be used to introduce opposing pressure by filling it with more fluid and when compared with an open ended system where an air vent is present to relieve pressure this solution eliminates the likelihood of drawing contaminants such as water into the cylinder or by the piston seals into the pressurized fluid side of the system.
The gap between the rear end of the ski and the brake blade is critical. The development of this ski brake determined that when braking, the disturbed running surface, snow, ice, etc. needs to find a place to release the braking loads and if this release location is readily available between the blade and the ski it will escape at that point, evidenced through the plume, rooster tail that gets larger the larger the gap and the higher the speed. Conversely, when the gap is reduced to a minimum the loads, forces, energy is then captured under the ski and greatly increases brake drag and brake performance.
While these additional subsystems are not being described in detail herein, it is certainly within the skill of the ordinary artisan in the field of mechanics and mechanical design to understand and implement many types of mechanisms or systems addressing the incorporation of any or all of the above subsystems into any one of the vehicles as described as the instant invention.
It is thought that the present gravity driven steerable vehicle, for use in riding or racing primarily down hill over varied terrain, and many of its attendant advantages is understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts thereof without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred or exemplary embodiment thereof.
Elements of the Invention
10 A four wheeled gravity driven steerable vehicle
10 A A four ski equipped gravity driven steerable vehicle
12 a chassis having
12 A chassis front portion,
12 B chassis rear portion,
12 C chassis underside and
12 D chassis top side;
14 a rider riding surface on said chassis top side 12 D configured to cause a rider to said ride riding surface 14 to be oriented in a prone, face down, face forward position;
16 means for attaching a rear axle assembly 16 A substantially at said chassis rear portion 12 B;
16 A a rear axle assembly
18 means for mounting a front axle assembly 18 A substantially at said chassis front portion 12 A;
18 A a front axle assembly
20 means for steering said gravity driven steerable wheeled vehicle 10 by said rider when said rider is positioned on said rider riding surface 14 ;
22 rear wheel hub and spindle assemblies integral with said rear axle assembly 16 A;
23 wheels and tires
24 front wheel hub and spindle assemblies integral with said front axle assembly 18 A.
26 braking system or means for causing deceleration and haulting of motion of said vehicle 10 when said vehicle has motion.
28 means for harnessing the rider onto and into said rider riding surface 14 when said rider is positioned on said vehicle 10
30 means for absorbing shock exerted on each said front wheels and tires 23 attached to each said two front wheel hub and spindle assemblies 24 thereby damping shock caused by said vehicle 10 passing over rough terrain, between said front wheels and tires 23 and said front axle assembly 18 A;
32 means for absorbing shock exerted on each said rear wheels and tires 23 attached to each said two rear wheel hub and spindle assemblies 22 thereby damping shock caused by said vehicle 10 passing over rough terrain, between said rear wheels and tires 23 and said rear axle assembly 16 A;
31 axle component
32 A a-arm
32 A 1 wheel and ski assembly attachment end
32 A 2 Shock absorber pivotal attachment end
32 A 3 a-arm pivot attached to axle 31
32 B shock absorber
32 B 1 shock absorber a-arm end
32 B 2 shock absorber axle pivotable attachment end
34 combination rear roll bar and transport bail
40 A three wheeled gravity driven steerable wheeled vehicle
40 A A gravity driven steeable vehicle with two skis in front and two wheels in the rear
70 ski assembly without ski braking assembly for attaching to a-arm
71 ski front end
71 A ski rear end/tail,
71 B ski running surface and
71 C ski upward-facing surface
72 ski post
74 ski foot
76 ski pivot
70 A ski assembly with ski braking assembly
80 ski braking assembly
84 brake blade
84 A gap between brake blade and ski rear end
82 brake arm
83 brake arm pivot
81 brake cylinder
85 brake cylinder mounting and pivot bracket
85 A brake cylinder pivot
86 sealed brake cylinder reservoir
88 brake return assembly
88 A brake return springs
88 B | A gravity driven steerable vehicle having wheels, or skis or a combination of wheels and skis for recreational use, most particularly on surfaces such as pavement, artificial hard-pack turf, mountain slopes, dirt roads, grass and hard-packed or non-packed snow. The vehicle has at least three (3) but preferably four (4) wheels, or skis or a combination of wheels and skis which may or may not be on independent axles one from the other and which may or may not be each independently shock suspended. There is also a steering mechanism for steering the vehicle and a driver compartment portion for containing a driver of the vehicle in a prone face-down and face-forward position. The vehicle is steerable by the driver from the prone face-down and face-forward position. The mechanism for suspension of the wheels and/or skis is configured to provide precise control in turns especially the carving of turns, by the skis, while descending on snow covered terrain. The attitude of the skis relative to the snow surface changes upon initiation of a turn and while in the turn to increase the edgeing of the skis thereby enhancing the turning characteristics of the vehicle. The vehicle may further have a braking system for slowing or stopping the vehicle and a harness apparatus for harnessing the driver onto and into the vehicle. | 0 |
PRIORITY
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 61/588,932, filed Jan. 20, 2012, entitled “Thin Airfoil Ceiling Fan Blade,” the disclosure of which is incorporated by reference herein.
BACKGROUND
[0002] A variety of fan systems have been made and used over the years in a variety of contexts. For instance, various ceiling fans are disclosed in U.S. Pat. No. 7,284,960, entitled “Fan Blades,” issued Oct. 23, 2007; U.S. Pat. No. 6,244,821, entitled “Low Speed Cooling Fan,” issued Jun. 12, 2001; U.S. Pat. No. 6,939,108, entitled “Cooling Fan with Reinforced Blade,” issued Sep. 6, 2005; and U.S. Pat. No. D607,988, entitled “Ceiling Fan,” issued Jan. 12, 2010. The disclosures of each of those U.S. patents are incorporated by reference herein. Additional exemplary fans are disclosed in U.S. Pat. No. 8,079,823, entitled “Fan Blades,” issued Dec. 20, 2011; U.S. Pat. Pub. No. 2009/0208333, entitled “Ceiling Fan System with Brushless Motor,” published Aug. 20, 2009; and U.S. Pat. Pub. No. 2010/0278637, entitled “Ceiling Fan with Variable Blade Pitch and Variable Speed Control,” published Nov. 4, 2010, the disclosures of which are also incorporated by reference herein. It should be understood that teachings herein may be incorporated into any of the fans described in any of the above-referenced patents, publications, or patent applications
[0003] A fan blade or airfoil may include one or more upper air fences and/or one or more lower air fences at any suitable position(s) along the length of the fan blade or airfoil. Merely exemplary air fences are described in U.S. Pat. Pub. No. 2011/0081246, entitled “Air Fence for Fan Blade,” published Apr. 7, 2011, the disclosure of which is incorporated by reference herein. Alternatively, any other suitable type of component or feature may be positioned along the length of a fan blade or airfoil; or such components or features may simply be omitted.
[0004] The outer tip of a fan blade or airfoil may be finished by the addition of an aerodynamic tip or winglet. Merely exemplary winglets are described in U.S. Pat. No. 7,252,478, entitled “Fan Blade Modifications,” issued Aug. 7, 2007, the disclosure of which is incorporated by reference herein. Additional winglets are described in U.S. Pat. No. 7,934,907, entitled “Cuffed Fan Blade Modifications,” issued May 3, 2011, the disclosure of which is incorporated by reference herein. Still other exemplary winglets are described in U.S. Pat. No. D587,799, entitled “Winglet for a Fan Blade,” issued Mar. 3, 2009, the disclosure of which is incorporated by reference herein. In some settings, such winglets may interrupt the outward flow of air at the tip of a fan blade, redirecting the flow to cause the air to pass over the fan blade in a perpendicular direction, and also ensuring that the entire air stream exits over the trailing edge of the fan blade and reducing tip vortex formation. In some settings, this may result in increased efficiency in operation in the region of the tip of the fan blade. In other variations, an angled extension may be added to a fan blade or airfoil, such as the angled airfoil extensions described in U.S. Pat. No. 8,162,613, entitled “Angled Airfoil Extension for Fan Blade,” issued Apr. 24, 2012, the disclosure of which is incorporated by reference herein. Other suitable structures that may be associated with an outer tip of an airfoil or fan blade will be apparent to those of ordinary skill in the art. Alternatively, the outer tip of an airfoil or fan blade may be simply closed (e.g., with a cap or otherwise, etc.), or may lack any similar structure at all.
[0005] The interface of a fan blade and a fan hub may also be provided in a variety of ways. For instance, an interface component is described in U.S. Pat. No. 8,147,204, entitled “Aerodynamic Interface Component for Fan Blade,” issued Apr. 3, 2012, the disclosure of which is incorporated by reference herein. In addition, or in the alternative, the fan blade may include a retention system that couples the tip of a fan blade to an attachment point on the fan hub via a cable running through the fan blade, such as that disclosed in U.S. Pat. Pub. No. 2011/0262278, published Oct. 27, 2011. Alternatively, the interface of a fan blade and a fan hub may include any other component or components, or may lack any similar structure at all.
[0006] Fans may also include a variety of mounting structures. For instance, a fan mounting structure is disclosed in U.S. Pat. No. 8,152,453, entitled “Ceiling Fan with Angled Mounting,” issued Apr. 10, 2012, the disclosure of which is incorporated herein. Of course, a fan need not be mounted to a ceiling or other overhead structure, and instead may be mounted to a wall or to the ground. For instance, a fan may be supported on the top of a post that extends upwardly from the ground. Examples of such mounting structures are shown in U.S. Design Pat. No. D635,237, entitled “Fan with Ground Support,” issued Mar. 29, 2011, the disclosure of which is incorporated by reference herein; U.S. Design Pat. No. D641,075, entitled “Fan with Ground Support and Winglets,” issued Jul. 5, 2011, the disclosure of which is incorporated by reference herein; and U.S. Pat. App. No. 61/720,077, entitled “Fan Mounting System,” filed Oct. 30, 2012, the disclosure of which is incorporated by reference herein. Alternatively, any other suitable mounting structures and/or mounting techniques may be used in conjunction with embodiments described herein.
[0007] It should also be understood that a fan may include sensors or other features that are used to control, at least in part, operation of a fan system. For instance, such fan systems are disclosed in U.S. Pat. No. 8,147,182, entitled “Ceiling Fan with Concentric Stationary Tube and Power-Down Features,” issued Apr. 3, 2012, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 8,123,479, entitled “Automatic Control System and Method to Minimize Oscillation in Ceiling Fans,” issued Feb. 28, 2012, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2010/0291858, entitled “Automatic Control System for Ceiling Fan Based on Temperature Differentials,” published Nov. 18, 2010, the disclosure of which is incorporated by reference herein; U.S. Provisional Patent App. No. 61/165,582, entitled “Fan with Impact Avoidance System Using Infrared,” filed Apr. 1, 2009, the disclosure of which is incorporated by reference herein; and U.S. Pat. App. No. 61/720,679, entitled “Integrated Thermal Comfort Control System Utilizing Circulating Fans,” filed Oct. 31, 2012, the disclosure of which is incorporated by reference herein. Alternatively, any other suitable control systems/features may be used in conjunction with embodiments described herein.
[0008] In some settings, it may be desirable to replicate or approximate the function of a winglet in a component that may be located at a position on a fan blade other than at the free end of the fan blade. For instance, such components are disclosed in U.S. Pat. Pub. No. 2011/0081246, entitled “Air Fence For Fan Blade,” published Apr. 7, 2011, the disclosure of which is incorporated by reference herein. Such a component may provide an effect on fan efficiency similar to the effect provide by a winglet, albeit at one or more additional regions of the fan blade. In particular, such a component or accessory may serve as an aerodynamic guide or air fence, interrupting slippage of air along the length or longitudinal axis of the fan blade; and redirecting the air flow to a direction perpendicular to the longitudinal axis of the fan blade, above and/or below the fan blade.
[0009] In some ceiling fans, flat planar blades are used by inclining the blades at an angle of approximately ten to twenty degrees from the horizontal to displace airflow in a downward direction. These flat blades might not be aerodynamically efficient in some settings. Accordingly, to move a given volume of air, the fan must operate at a higher speed, thereby consuming more electricity. In addition, these flat blades might be manufactured from wood or fiberboard, harvested from trees, such as Monterey Pine, which typically take 25-30 years to reach maturity. Since the regrowth time of the raw materials may exceed the lifespan of the ceiling fan, continued production in this manner is not an environmentally sustainable practice.
[0010] While flat planar blades have been used, attempts have been made to improve upon ceiling fan blade designs. For example, Parker, et al, U.S. Pat. No. 6,039,541, issued Mar. 21, 2000, describes a ceiling fan blade that includes the SD7032, GM15, MA409, and Hibbs 504 airfoils. Airfoils of this type may operate with higher coefficients of lift versus angle of attack at Reynolds numbers greater than 100,000. In the instance of a fan blade with a chord length of 10.16 centimeters (4 inches) and blade span with the root located 22.5 centimeters (9 inches) from the center of rotation and a tip located 76.2 centimeters (30 inches) from the center of rotation, operating at 50 rotations per minute may experience Reynolds numbers ranging from 8,000 at the root to 28,000 at the tip. While at 200 rotations per minute, the fan blade may experience Reynolds numbers ranging from 33,000 at the root to 110,000 at the tip. At speeds below 180 rotations per minute, the entire blade may experience Reynolds numbers less than 100,000. Accordingly, the airfoils described by Parker, et al. may operate below their optimal performance under the majority of operating conditions for the ceiling fan. Furthermore, airfoil blades of the types disclosed in Parker, et al. may increase manufacturing complexity since the airfoil thickness has a teardrop profile and varies substantially from leading edge to trailing edge. In some instances, to create this teardrop profile the blade must be manufactured by plastic injection molding or, alternatively, machined from a flat sheet material, which may result in significant wastage. Thus, a need exists for an improved blade design that offers optimal airflow performance at the low Reynolds numbers experienced by a ceiling fan and is capable of being manufactured by simple techniques using sustainable materials.
[0011] While several systems and methods have been made and used for ceiling fan blades, it is believed that no one prior to the inventors has made or used the invention described in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] While the specification concludes with claims which particularly point out and distinctly claim this technology, it is believed this technology will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:
[0013] FIG. 1 depicts a front perspective view of an exemplary fan having a plurality of exemplary ceiling fan blades attached thereto;
[0014] FIG. 2 depicts an exploded perspective view of the fan of FIG. 1 ;
[0015] FIG. 3 depicts an side elevation view of the fan of FIG. 1 ;
[0016] FIG. 4 depicts a plan view of the exemplary ceiling fan blade of FIGS. 1-3 ;
[0017] FIG. 4A depicts a cross-sectional view of the ceiling fan blade of FIG. 4 taken along section line A-A of FIG. 4 ;
[0018] FIG. 4B depicts a cross-sectional view of the ceiling fan blade of FIG. 4 taken along section line B-B of FIG. 4 ;
[0019] FIG. 4C depicts a cross-sectional view of the ceiling fan blade of FIG. 4 taken along section line C-C of FIG. 4 ;
[0020] FIG. 5 depicts a combination cross-sectional view of the blade sections shown in FIGS. 4A-4C , showing the relative curvature of each section;
[0021] FIG. 6 depicts a front elevation view of the fan blade of FIGS. 1-5 ;
[0022] FIG. 7 depicts a perspective view of an alternative fan having a plurality of exemplary ceiling fan blades attached thereto;
[0023] FIG. 8 depicts an exploded perspective view of the fan of FIG. 7 ;
[0024] FIG. 9 depicts a plan view of the exemplary fan blade of FIG. 7 ; and
[0025] FIG. 10 depicts an elevation view taken from a root end of the fan blade of FIG. 9 .
[0026] The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the technology may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present technology, and together with the description serve to explain the principles of the technology; it being understood, however, that this technology is not limited to the precise arrangements shown.
DETAILED DESCRIPTION
[0027] The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.
[0028] I. Exemplary Fan Overview
[0029] Referring to FIG. 1 , a fan ( 10 ) of the present example comprises a support ( 20 ), a motor ( 30 ) (shown in FIG. 2 ), and a plurality of fan blades ( 50 ). While three fan blades ( 50 ) are shown, it should be understood that any other suitable number of fan blades ( 50 ) may be used. Fan blades ( 50 ) of the present example may define a fan diameter ranging from approximately 0.5 meters (1.64 feet), inclusive, to approximately 5 meters (16.4 feet), inclusive. In the present example, fan blades ( 50 ) define a fan diameter of approximately 1.5 meters (4.92 feet). Alternatively, fan ( 10 ) and/or fan blades ( 50 ) may have any other suitable dimensions.
[0030] Support ( 20 ) is configured to be coupled to a surface or other structure at a first end such that fan ( 10 ) is substantially attached to the surface or other structure. Support ( 20 ) of the present example comprises an elongate metal tube-like structure that couples fan ( 10 ) to a ceiling, though it should be understood that support ( 20 ) may be constructed and/or configured in a variety of other suitable ways as will be apparent to one of ordinary skill in the art in view of the teachings herein. In one merely exemplary version, support ( 20 ) is configured to couple to an electrical junction box (not shown) located within or on a ceiling. With support ( 20 ) comprising an elongate metal tube, wires or other power supply or control members are extended through support ( 20 ) to motor ( 30 ). By way of example only, support ( 20 ) need not be coupled to a ceiling or other overhead structure, and instead may be coupled to a wall or to the ground. For instance, support ( 20 ) may be positioned on the top of a post that extends upwardly from the ground. Alternatively, support ( 20 ) may be mounted in any other suitable fashion at any other suitable location. This includes, but is not limited to, the teachings of the patents, patent publications, or patent applications cited herein. By way of example only, support ( 20 ) may be configured in accordance with the teachings of U.S. Pat. Pub. No. 2009/0072108, entitled “Ceiling Fan with Angled Mounting,” published Mar. 19, 2009, the disclosure of which is incorporated by reference herein. As yet another alternative, support ( 20 ) may have any other suitable configuration.
[0031] As shown in FIG. 2 , fan ( 10 ) of the present example includes a motor ( 30 ) that is coupled to fan blades ( 50 ). Motor ( 30 ) of the present example is coupled to fan blades ( 50 ) via fasteners ( 32 ). Fasteners ( 32 ) may include screws, bolts, clips, clamps, and/or any other suitable fastener ( 32 ) for coupling fan blades ( 50 ) to motor ( 30 ). Alternatively, fasteners ( 32 ) may be omitted and fan blades ( 50 ) may be adhesively attached or integrally formed with a portion of motor ( 30 ) such that fan blades ( 50 ) rotate when motor ( 30 ) is operated. In the present example, a blade shoe ( 40 ) is interposed between motor ( 30 ) and each fan blade ( 50 ). In some versions, blade shoe ( 40 ) may comprise a rubber, synthetic rubber, or other vibratory buffering material such that fan blades ( 50 ) are substantially isolated from vibrations of motor ( 30 ) and/or other portions of fan ( 10 ). Alternatively, blade shoe ( 40 ) may comprise a plastic, metal, wood, composite, and/or any other material. Of course it should be understood that blade shoe ( 40 ) is merely optional and may be omitted.
[0032] In some versions, motor ( 30 ) comprises an AC induction motor having a drive shaft, though it should be understood that motor ( 30 ) may alternatively comprise any other suitable type of motor (e.g., a permanent magnet brushless DC motor, a brushed motor, an inside-out motor, etc.). In the present example, motor ( 30 ) is fixedly coupled to support ( 20 ) and is configured to rotate fan blades ( 50 ) relative to support ( 20 ) such that air is propelled by fan ( 10 ) away from the structure to which support ( 20 ) is coupled. In an alternative version, shown in FIGS. 7-10 , a hub ( 430 ) may be included in addition to, or instead of, blade shoes ( 40 ). In the version shown in FIGS. 7-10 , hub ( 430 ) comprises an annular member having a plurality of holes ( 432 ) disposed about the circumference to which fan blades ( 50 ) may be coupled. Hub ( 430 ) is coupled to motor ( 30 ) such that rotation of hub ( 430 ) by motor ( 30 ) rotates fan blades ( 50 ). Of course motor ( 30 ) may be constructed in accordance with at least some of the teachings of U.S. Pat. Pub. No. 2009/0208333, entitled “Ceiling Fan System with Brushless Motor,” published Aug. 20, 2009, the disclosure of which is incorporated by reference herein. Furthermore, fan ( 10 ) may include control electronics that are configured in accordance with at least some of the teachings of U.S. Pat. Pub. No. 2010/0278637, entitled “Ceiling Fan with Variable Blade Pitch and Variable Speed Control,” published Nov. 4, 2010, the disclosure of which is incorporated by reference herein. Of course, motor ( 30 ), blade shoe ( 40 ), and/or hub ( 430 ) may have any other suitable components, configurations, functionalities, and operability, as will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0033] In the present example, fan ( 10 ) further includes a top cover ( 34 ). Top cover ( 34 ) comprises a dome-shaped component configured to enclose the top of motor ( 30 ). Top cover ( 34 ) of the present example is attached to support ( 20 ) to form a dome over the top of motor ( 30 ) when motor ( 30 ) is coupled to support ( 20 ). In some versions, top cover ( 34 ) is threadably coupled to support ( 20 ). In other versions, top cover ( 34 ) may be integrally formed with support ( 20 ), coupled via fasteners (not shown), or otherwise attached to support ( 20 ) and/or motor ( 30 ). When fan blades ( 50 ) of the example shown in FIGS. 1-3 are coupled to motor ( 30 ), fan blades ( 50 ) and top cover ( 34 ) substantially enclose motor ( 30 ), as seen best in FIG. 1 .
[0034] Fan blades ( 50 ) of the example shown in FIGS. 1-6 each include an arcuate cutout ( 54 ) at a root end ( 52 ) of each fan blade ( 50 ). When fan blades ( 50 ) are coupled to motor ( 30 ), arcuate cutouts ( 54 ) form a cylindrical aperture ( 56 ). A semi-transparent lens ( 48 ) is inserted into aperture ( 56 ). A sensor (not shown) is mounted within aperture ( 56 ) and is configured to receive infrared signals from a remote control (not shown) or other source. The sensor is coupled to a motor control module that is operable to control fan ( 10 ). Fan ( 10 ) may be further configured in accordance with at least some of the teachings of the fan systems disclosed in U.S. Pat. Pub. No. 2009/0097975, entitled “Ceiling Fan with Concentric Stationary Tube and Power-Down Features,” published Apr. 16, 2009, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2009/0162197, entitled “Automatic Control System and Method to Minimize Oscillation in Ceiling Fans,” published Jun. 25, 2009, the disclosure of which is incorporated by reference herein; U.S. Pat. Pub. No. 2010/0291858, entitled “Automatic Control System for Ceiling Fan Based on Temperature Differentials,” published Nov. 18, 2010, the disclosure of which is incorporated by reference herein; and U.S. Provisional Patent App. No. 61/165,582, entitled “Fan with Impact Avoidance System Using Infrared,” filed Apr. 1, 2009, the disclosure of which is incorporated by reference herein Still further configurations for lens ( 48 ), arcuate cutouts ( 54 ), aperture ( 56 ), and the sensor will be apparent to one of ordinary skill in the art in view of the teachings herein. Of course, it should be understood that lens ( 48 ), arcuate cutouts ( 54 ) and aperture ( 56 ) are merely optional and may be omitted.
[0035] While some merely exemplary features of fan ( 10 ) have been described herein, it should be understood that fan ( 10 ) may have other features, components, and/or configurations as will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0036] II. Exemplary Fan Blades
[0037] A single fan blade ( 50 ) is shown plan form in FIG. 4 having a root end ( 52 ), a tip ( 70 ), a leading edge ( 80 ) and a trailing edge ( 90 ). Sections A-A, B-B, and C-C are shown in FIG. 4 and correspond to cross-sectional FIGS. 4A , 4 B, and 4 C, respectively. Sections A-A, B-B, and C-C will be discussed in greater detail below. As noted above, root end ( 52 ) of the present example comprises an arcuate cutout ( 54 ) configured to permit lens ( 48 ) be inserted in a central aperture ( 56 ) formed when fan blades ( 50 ) are mounted. Root end ( 52 ) further includes a pair of openings ( 58 ) that permit fasteners ( 32 ) to extend therethrough to couple fan blade ( 50 ) to motor ( 30 ) and/or hub ( 42 ). As shown in FIGS. 1-3 , root end ( 52 ) of the present exemplary fan blade ( 50 ) comprises a domed sector that corresponds to an approximately 120 degree sector of a dome for the present fan ( 10 ) having three fan blades ( 50 ). The domed sector of root end ( 52 ) is substantially flat, or parallel, relative to the plane of rotation for fan blades ( 50 ) at or near arcuate cutout ( 54 ). The domed sector curves upwardly toward motor ( 30 ) and/or support ( 20 ). Root end ( 52 ) may of course include an approximately 180 degree, 90 degree, 60 degree, 45 degree and/or any other sector portion of a dome or may omit a domed sector end. Of course other root ends ( 52 ) will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0038] Fan blade ( 50 ) also includes a transition region ( 60 ) extending from root end ( 52 ), shown best in FIGS. 4 and 6 . In the present example, transition region ( 60 ) comprises a first portion ( 62 ), an inflection portion ( 64 ), and a second portion ( 66 ). First portion ( 62 ) comprises an extension of the domed sector of root end ( 52 ) that terminates at inflection portion ( 64 ). Inflection portion ( 64 ) of the present example comprises a quasi-parabolic shaped portion that extends from leading edge ( 80 ) to trailing edge ( 90 ) and transitions fan blade ( 50 ) from the upwardly extending domed shape of first portion to a planar portion. Second portion ( 66 ) extends from inflection portion ( 64 ) and transitions fan blade ( 50 ) from the planar inflection portion ( 64 ) to the downwardly curved root airfoil profile ( 100 ), shown in FIG. 4A . By way of example only, a non-dimensional matrix of coordinates in Table 1 below generally describes the surface formed by transition region ( 60 ) and airfoil profile ( 100 ). It should be understood that the domed sector of root end ( 52 ) is omitted from the coordinates in Table 1. In addition, the Z coordinate corresponds to the vertical height of the point at the transition point from root end ( 52 ) (e.g., a height of 0 corresponds to where root end ( 52 ) ends and transition region ( 60 ) beings), the X coordinate corresponds to the longitudinal distance from a central point about which blade ( 50 ) rotates, and the Y coordinate corresponds to the chord-wise position, where negative coordinates approach trailing edge ( 90 ) and positive coordinates approach leading edge ( 80 ).
[0000]
TABLE 1
Z
X
Y
0
0.0892
−0.01
0
0.0991
−0.009
0
0.1072
−0.008
0
0.1145
−0.007
0
0.1209
−0.006
0
0.1263
−0.005
0
0.1305
−0.004
0
0.1337
−0.003
0
0.1358
−0.002
0
0.137
−0.001
0
0.1373
0
0
0.1366
0.001
0
0.1351
0.002
0
0.1327
0.003
0
0.1294
0.004
0
0.1252
0.005
0
0.1201
0.006
0
0.1141
0.007
0
0.1071
0.008
0
0.0989
0.009
0
0.0888
0.01
0.005
0.0986
−0.01
0.005
0.1273
−0.009
0.005
0.1897
−0.008
0.005
0.1452
−0.007
0.005
0.1471
−0.006
0.005
0.1521
−0.005
0.005
0.1564
−0.004
0.005
0.1595
−0.003
0.005
0.1614
−0.002
0.005
0.1621
−0.001
0.005
0.1617
0
0.005
0.1602
0.001
0.005
0.1578
0.002
0.005
0.1544
0.003
0.005
0.1501
0.004
0.005
0.145
0.005
0.005
0.139
0.006
0.005
0.1322
0.007
0.005
0.1248
0.008
0.005
0.1166
0.009
0.01
0.4002
−0.007
0.01
0.3408
−0.006
0.01
0.286
−0.005
0.01
0.1931
−0.004
0.01
0.1902
−0.003
0.01
0.1913
−0.002
0.01
0.1909
−0.001
0.01
0.1892
0
0.01
0.1863
0.001
0.01
0.1824
0.002
0.01
0.1776
0.003
0.01
0.1718
0.004
0.01
0.1653
0.005
0.01
0.1581
0.006
0.01
0.1503
0.007
0.01
0.1421
0.008
0.015
0.4724
−0.007
0.015
0.4133
−0.006
0.015
0.3586
−0.005
0.015
0.3085
−0.004
0.015
0.2616
−0.003
0.015
0.2246
−0.002
0.015
0.2212
−0.001
0.015
0.2175
0
0.015
0.2126
0.001
0.015
0.2067
0.002
0.015
0.2
0.003
0.015
0.1926
0.004
0.015
0.1846
0.005
0.015
0.1762
0.006
0.015
0.1675
0.007
0.015
0.1585
0.008
0.02
0.5299
−0.007
0.02
0.4852
−0.006
0.02
0.4308
−0.005
0.02
0.3807
−0.004
0.02
0.3352
−0.003
0.02
0.2942
−0.002
0.02
0.2551
−0.001
0.02
0.2442
0
0.02
0.2369
0.001
0.02
0.2289
0.002
0.02
0.2204
0.003
0.02
0.2115
0.004
0.02
0.2023
0.005
0.02
0.1929
0.006
0.02
0.1834
0.007
0.02
0.1745
0.008
0.025
0.5627
−0.006
0.025
0.5024
−0.005
0.025
0.4526
−0.004
0.025
0.4072
−0.003
0.025
0.3662
−0.002
0.025
0.3296
−0.001
0.025
0.2975
0
0.025
0.2696
0.001
0.025
0.2502
0.002
0.025
0.2395
0.003
0.025
0.2297
0.004
0.025
0.2203
0.005
0.025
0.2117
0.006
0.025
0.2042
0.007
0.025
0.1988
0.008
0.03
0.5734
−0.005
0.03
0.5241
−0.004
0.03
0.4789
−0.003
0.03
0.438
−0.002
0.03
0.4014
−0.001
0.03
0.3692
0
0.03
0.3412
0.001
0.03
0.3175
0.002
0.03
0.2977
0.003
0.03
0.2818
0.004
0.03
0.2696
0.005
0.03
0.2614
0.006
0.03
0.2566
0.007
0.03
0.2548
0.008
0.035
0.595
−0.004
0.035
0.5502
−0.003
0.035
0.5095
−0.002
0.035
0.473
−0.001
0.035
0.4408
0
0.035
0.4128
0.001
0.035
0.3891
0.002
0.035
0.3693
0.003
0.035
0.3535
0.004
0.035
0.3414
0.005
0.035
0.333
0.006
0.035
0.328
0.007
0.035
0.3264
0.008
0.04
0.6211
−0.003
0.04
0.5808
−0.002
0.04
0.5445
−0.001
0.04
0.5124
0
0.04
0.4844
0.001
0.04
0.4606
0.002
0.04
0.4409
0.003
0.04
0.4252
0.004
0.04
0.4133
0.005
0.04
0.4051
0.006
0.04
0.4005
0.007
0.04
0.3994
0.008
[0039] Of course, it should be understood that other configurations for transition region ( 60 ) and/or other regions of fan blade ( 50 ) may be used. For instance, if root end ( 52 ) omits a domed sector, then fan blade ( 50 ) may omit first portion ( 62 ) and, in some versions, inflection portion ( 64 ), having only second portion ( 66 ) transition to root airfoil profile ( 100 ) directly. Still further constructions for transition region ( 60 ), etc., will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0040] Referring now to FIG. 4A , a cross-sectional root airfoil profile ( 100 ) is shown taken along section A-A of FIG. 4 . Root airfoil profile ( 100 ) comprises a top surface ( 102 ), a bottom surface ( 104 ), a leading edge ( 106 ), and a trailing edge ( 108 ). Root airfoil profile ( 100 ) of the present example comprises a curved airfoil having a substantially constant thickness ( 110 ) and a substantially constant radius of curvature ( 120 ). By way of example only, thickness ( 110 ) may range from approximately 1 millimeter (0.03937 inches), inclusive, to approximately 5 millimeters (0.19685 inches), inclusive. In the example shown, thickness ( 110 ) is approximately 4 millimeters (0.15748 inches) though this is merely one embodiment. Still further values for thickness ( 110 ) will be apparent to one of ordinary skill in the art in view of the teachings herein. Also by way of example only, radius of curvature ( 120 ) is measured from a center point ( 118 ) and may range from approximately 2 meters (6.56167 feet), inclusive, to approximately 5 meters (16.4042 feet), inclusive. In the example shown, radius of curvature ( 120 ) is approximately 3.7 meters (12.1391 feet). Still further values for radius of curvature ( 120 ) will be apparent to one of ordinary skill in the art in view of the teachings herein. In the example shown in FIG. 4A , root airfoil profile ( 100 ) is defined when radius of curvature ( 120 ) is swept through a root angle ( 122 ). Root angle ( 122 ) of the present example is approximately 14 degrees, though it should be understood that this is merely exemplary and other smaller and/or larger root angles ( 122 ) will be apparent to one of ordinary skill in the art in view of the teachings herein. Furthermore, leading edge ( 106 ) and trailing edge ( 108 ) comprise rounded surfaces connecting top surface ( 102 ) to bottom surface ( 104 ), though this is merely optional. Leading edge ( 102 ) and trailing edge ( 104 ) of the present example form rounded surfaces having a radius of curvature substantially equal to thickness ( 110 ). Thus, as shown in FIG. 4A , a substantially constant thickness root airfoil profile ( 100 ) is formed.
[0041] FIG. 4B depicts a cross-sectional intermediate airfoil profile ( 200 ) taken along section B-B of FIG. 4 at an approximate midpoint between root airfoil profile ( 100 ) and tip airfoil profile ( 300 ), discussed in greater detail below. It should be understood that while the term intermediate is used, it does not necessarily connote that the shape, size, or values defining intermediate airfoil profile ( 200 ) are in between those of root airfoil profile ( 100 ) and tip airfoil profile ( 300 ). Intermediate airfoil profile ( 200 ) of the present example comprises a top surface ( 202 ), a bottom surface ( 204 ), a leading edge ( 206 ), and a trailing edge ( 208 ). Intermediate airfoil profile ( 200 ) of the present example is substantially identical to root airfoil profile ( 100 ) and has a substantially identical thickness ( 110 ) and is defined by a substantially identical radius of curvature ( 120 ) with the exception that radius of curvature ( 120 ) is swept through an intermediate angle ( 222 ). By way of example only, intermediate angle ( 222 ) is approximately 12.5 degrees, though of course other smaller and/or larger intermediate angles ( 222 ) will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0042] FIG. 4C shows a cross-sectional tip airfoil profile ( 300 ) taken along section C-C of FIG. 4 at an approximate tip ( 70 ) of fan blade ( 50 ). Tip airfoil profile ( 300 ) of the present example comprises a top surface ( 302 ), a bottom surface ( 304 ), a leading edge ( 306 ), and a trailing edge ( 308 ). Tip airfoil profile ( 300 ) of the present example is substantially identical to root airfoil profile ( 100 ) and has a substantially identical thickness ( 110 ) and is defined by a substantially identical radius of curvature ( 120 ) with the exception that radius of curvature ( 120 ) is swept through a tip angle ( 322 ). By way of example only, tip angle ( 322 ) is approximately 7 degrees, though of course other smaller and/or larger tip angles ( 322 ) will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0043] FIG. 5 depicts a composite overlay of the cross-sections of FIGS. 4A-4C . As noted above, root airfoil profile ( 100 ), intermediate airfoil profile ( 200 ), and tip airfoil profile ( 300 ) are substantially identical in shape and thickness with the exception of each being formed by sweeping radius of curvature ( 120 ) to various angle ( 122 , 222 , 322 ). In some versions, the tip angle ( 322 ) is a minimum value for the angles through which radius of curvature ( 120 ) is swept while root angle ( 122 ) is a maximum value for fan blade ( 50 ). Though, it should be understood that tip angle ( 322 ) need not necessarily be the minimum value for the angles through which radius of curvature ( 120 ) is swept and/or root angle ( 122 ) need not necessarily be the maximum value for the angles through which radius of curvature ( 120 ) is swept. In addition, or in the alternative, angles ( 122 , 222 , 322 ) may linearly increase in value from tip angle ( 322 ) to root angle ( 122 ). In other versions, angles ( 122 , 222 , 322 ) may increase in value logarithmically, parabolically, cubically, and/or in any other manner from tip angle ( 322 ) to root angle ( 122 ). Referring briefly to FIG. 6 , fan blade ( 50 ) is also configured to have a blade rise angle ( 98 ). In the example shown, blade rise angle ( 98 ) corresponds to the angle formed between the plane in which the fan rotates and the top surface of fan blade ( 50 ). Thus, the absolute height of each fan blade ( 50 ) increases from root end ( 52 ) to tip ( 70 ). By way of example only, blade rise angle ( 98 ) may be an angle of approximately 0 degrees, inclusive, to approximately 20 degrees, inclusive. More specifically, blade rise angle ( 98 ) may be from 2.5 degrees, inclusive, to 5 degrees, inclusive. In the example shown, blade rise angle ( 98 ) is approximately 3.8 degrees. Still further configurations for airfoil profiles ( 100 , 200 , 300 ) and/or fan blade ( 50 ) will be apparent to one of ordinary skill in the art in view of the teachings herein. By way of example only, flaps, slats, extensions, electrical or mechanical actuators, and/or other features may be added to fan blades ( 50 ).
[0044] Fan blade ( 50 ) of the present example is manufactured from thin sheets of material laminated together. For instance, fan blade ( 50 ) may be constructed by combining individual sheets with adhesive between each layer and forcing the sheets together under pressure in a shaped mold to form fan blade ( 50 ) shown in FIGS. 1-6 . By way of example only, fan blade ( 50 ) may be manufactured using 7 layers of 0.5 millimeter (0.019685 inches) thick bamboo veneer that are compressed together as described above. Of course other thicknesses and/or number of layers may be used. Alternatively, other types of wooden veneer may be used or may be combined with other woods to form composite fan blades ( 50 ). In yet a further alternative, fan blade ( 50 ) may be formed from of a thermoplastic resin that is injected into a mold for fan blade ( 50 ) to achieve the desired profile. Further still, fan blade ( 50 ) may be formed from a single layer of plastic that is heated and bent or inserted into a mold to form the profile of fan blade ( 50 ). In still a further alternative, fan blade ( 50 ) may be formed from layers of fiberglass matting or carbon fiber composite materials combined with epoxy resins. In yet another alternative, layers of wood veneer or other materials (e.g., carbon fiber, fiberglass, etc.) may initially be layered within a mold and plastic or another resin may be injected or otherwise added to form fan blade ( 50 ). Of course still further constructions for fan blade ( 50 ) will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0045] III. Exemplary Alternative Fan
[0046] FIGS. 7-10 depict an alternative fan ( 400 ) having a support ( 410 ), a motor ( 420 ), a hub ( 430 ), and a plurality of fan blades ( 450 ). Support ( 410 ) and motor ( 420 ) of the present example may be constructed in substantial accordance with support ( 20 ) and motor ( 30 ) described above. Hub ( 430 ), shown best in FIG. 8 , comprises an annular member disposed about and coupled to motor ( 420 ) such that rotation of motor ( 420 ) rotates hub ( 430 ). Hub ( 430 ) further includes a plurality of holes ( 432 ) to which fasteners ( 434 ) may be coupled to substantially fixedly coupled fan blades ( 450 ) with hub ( 430 ). Accordingly, when motor ( 420 ) rotates, fan blades ( 450 ) and hub ( 430 ) also rotate. It should be understood that additional components, such as grommets or other vibratory-reducing members may be included between fan blades ( 450 ) and hub ( 430 ) and/or between hub ( 430 ) and motor ( 420 ). In the present example, fan ( 400 ) further includes a top cover ( 412 ) having a circular center (not shown) and a plurality of rectangular fan extensions ( 414 ). In the present example, rectangular fan extensions ( 414 ) curve downwardly relative to support ( 410 ) and are configured to nest within top recesses ( 454 ) formed in fan blades ( 450 ), described below, to form a substantially smooth transition between top cover ( 414 ) and fan blades ( 450 ).
[0047] A circular bottom cover ( 416 ) includes a plurality of upwardly projecting L-shaped tabs ( 418 ) disposed about the circumference of bottom cover ( 416 ) and a central lens ( 419 ). Lens ( 419 ) may be constructed in accordance with lens ( 48 ) described above. Bottom cover ( 416 ) is configured to couple to a bottom portion of fan blades ( 450 ) via tabs ( 418 ) inserting into recesses (not shown) formed in fan blades ( 450 ) and then being rotated such that an axial projection from each tab locks into the recesses. Accordingly, when bottom cover ( 416 ) is coupled to fan blades ( 450 ), a substantially smooth lower surface for fan ( 400 ) is formed. Of course it should be understood that bottom cover ( 416 ) may couple to fan blades ( 450 ) through other attachment members, such as screws, bolts, clips, clamps, straps, resilient tabs, etc. In addition, or in the alternative, bottom cover ( 416 ) may be directly coupled to motor ( 420 ). Fan ( 400 ) may be further configured in accordance with the teachings of fan ( 10 ) described above or in any other manner as will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0048] Referring now to FIGS. 9-10 , fan blade ( 450 ) of the present example comprises a root end ( 452 ), a tip ( 470 ), a leading edge ( 480 ), and a trailing edge ( 490 ). Fan blade ( 450 ) of the present example comprises airfoil profiles that substantially correspond to airfoil profiles ( 100 , 200 , 300 ) described above. In the present example, however, fan blade ( 450 ) comprises an alternative root end ( 452 ) and transition region ( 466 ). Transition region ( 466 ) of the present example comprises a tapered portion of fan blade ( 450 ) that transitions from root end ( 452 ) to airfoil profiles ( 100 , 200 , 300 ) for fan blade ( 450 ). Root end ( 452 ) of the present example includes a top recess ( 454 ) configured to receive a respective extension ( 414 ) therein. Thus, when extensions ( 414 ) are nested within respective top recesses ( 454 ) a substantially smooth transition is formed from top cover ( 414 ) to fan blades ( 450 ) for fan ( 400 ). In addition, one or more openings ( 456 ) are formed through a lower portion of root end ( 452 ) to permit fasteners ( 434 ) therethrough to substantially fixedly coupled fan blade ( 450 ) to hub ( 430 ) described above.
[0049] Root end ( 452 ) is further includes a recessed ledge ( 458 ) and an outer lip ( 460 ) disposed on opposing ends of root end ( 452 ). As shown in FIGS. 8-9 , recessed ledge ( 458 ) corresponds to the side of fan blade ( 450 ) with leading edge ( 480 ) while outer lip ( 460 ) corresponds to the side of fan blade ( 450 ) with trailing edge ( 490 ). Accordingly, when fan blades ( 450 ) are assembled for fan ( 400 ), recessed ledge ( 458 ) nests with and below outer lip ( 460 ) of the fan blade ( 450 ) to form a substantially smooth and continuous surface from one fan blade ( 450 ) to the next. In the present example, fan blades ( 450 ) have root ends ( 452 ) with recessed ledges ( 458 ) and outer lips ( 460 ) disposed approximately 120 degrees from each other such that three fan blades ( 450 ) may be combined to form a substantially continuous fan blade structure (as shown in FIG. 7 ). Of course it should be understood that other angular relationships may be used as well (e.g., 180 degrees for a dual fan blade ( 450 ) assembly, 90 degrees for a four fan blade ( 450 ) assembly, 60 degrees for a five fan blade ( 450 ) assembly, etc.). In addition, or in the alternative, fasteners (not shown) may be used to couple corresponding recessed ledges ( 458 ) and outer lips ( 460 ) together for fan blades ( 450 ). Further still, rubber grommets (not shown) or other vibratory-reducing members may be interposed between corresponding recessed ledges ( 458 ) and outer lips ( 460 ) to vibrationally isolate fan blades ( 450 ) from one another. In the present example, a pair of rib members ( 462 ) are provided within root end ( 452 ) to reinforce or otherwise provide additional rigidity to root end ( 452 ), though these are merely optional. Still further constructions for root end ( 452 ) and/or fan blade ( 450 ) will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0050] Fan blade ( 450 ) of the present example is manufactured by a thermoplastic resin that is injected into a mold for fan blade ( 450 ) to achieve the desired profile. Alternatively, fan blade ( 450 ) may be formed from thin sheets of material laminated together and anchored to a thermoplastic or other material root end ( 452 ). For instance, fan blade ( 450 ) may be constructed by combining individual sheets with adhesive between each layer and forcing the sheets together under pressure in a shaped mold to form fan blade ( 450 ) shown in FIGS. 9-10 and anchored to root end ( 452 ). In one version, fan blade ( 450 ) may be manufactured using 7 layers of 0.5 millimeter (0.019685 inches) thick bamboo veneer that are compressed together as described above. Of course other thicknesses and/or number of layers may be used. Alternatively, other types of wooden veneer may be used or may be combined with other woods to form composite fan blades ( 450 ). Further still, fan blade ( 450 ) may be formed from a single layer of plastic that is heated and bent or inserted into a mold to form the profile of fan blade ( 450 ) which is subsequently joined to root end ( 452 ). In still a further alternative, fan blade ( 450 ) may be formed from layers of fiberglass matting or carbon fiber composite materials combined with epoxy resins. In yet another alternative, layers of wood veneer or other materials (e.g., carbon fiber, fiberglass, etc.) may initially be layered within a mold and plastic or another resin may be injected or otherwise added to form fan blade ( 450 ). Of course still further constructions for fan blade ( 450 ) will be apparent to one of ordinary skill in the art in view of the teachings herein.
[0051] It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.
[0052] Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometrics, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not necessarily required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings. | A fan blade comprising a root end, a blade region, and a transition region. Wherein each of the root end and blade region comprise a unique profile, and wherein the transition region comprises a profile which transitions the root end profile to the blade region profile. The root end profile comprises a substantially convex top surface, a substantially concave domed sector, and reliefs to allow for the root end to be coupled with a similarly shaped fan hub extrusion. The blade region profile comprises a substantially convex top surface and bottom surface which terminate at a leading edge and trailing edge. The blade region slopes upward along a length of the blade region and terminates at a curved tip. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to U.S. Provisional Application Ser. No. 60/601051, filed on Aug. 13, 2004.
BACKGROUND OF THE INVENTION
[0002] a. Field of the Invention
[0003] This invention relates in general to the field of material handling equipment and in particular to medical material handling apparatus and more particularly to the construction of a tray and cover for primary use in the medical field.
[0004] b. Description of the Prior Art
[0005] There exists a problem in the prior art in the efficient, sterile and convenient storage and transfer of various medical equipment, drugs, specimens, vials, and other such medical paraphernalia and materials. In the past a simply constructed fiberglass tray having a bottom with four sides extending upward therefrom has been employed for the storage and transfer of the described medical materials. Such simply constructed trays usually have an open top.
[0006] One problem associated with the prior art trays is that the fiberglass generates small particles that can contaminate whatever is being stored in the trays. Continual usage and transfer of the trays exacerbate the particle generation and resulting contamination problem. Decontamination of the prior art fiberglass trays by the generally known and used methods in the medical field can cause deterioration of the fiberglass and make it more susceptible to the particle generation problem. For example, both usage and decontamination can cause deterioration of the fiberglass finish coat exposing the glass and resin under the finish coat which can then result in particles of glass and resin. Equally important is that prior art fiberglass trays have been known to fracture. Even a small fracture during usage can generate talc, resin, glass and other particles that can and will contaminate the interior of the prior art trays and the contents within the tray
[0007] Additional problems are associated with the prior art trays is that the open top does not prevent the entrance of other contaminates and does not provide for security and/or tamper evidence of the materials being stored in the trays.
[0008] Another prior art tray comprises the tray being made from stainless steel. While stainless steel trays do provide for decontamination and are generally superior to fiberglass trays, they are expensive, heavy and can generate metallic particles. Moreover, if stainless steel trays incorporate a provision for stacking one on top of another, they become especially expensive.
[0009] Thus, there exists the need for a tray construction that allows for convenient, secure, ready accessibility to the interior thereof, that lessens the problem of contamination, that allows for decontamination without deterioration of the tray itself, and that can be used with a transfer cart, or that can be used for general purposes. These needs have been a long standing problem in the prior art which are overcome by the present invention.
SUMMARY OF THE INVENTION
[0010] The present invention accomplishes the above-stated objectives as well as others, as may be determined by a fair reading and interpretation of the entire specification herein including the drawings and the claims, which comprises a unique medical storage and transfer tray having a storage member, a removable front side, and a cover member. In a preferred embodiment, the storage member includes a bottom surface, two vertical side members connected to a vertical back member, and a removable front member. The cover member includes a vertical front member connected to a top member with the front member having an inwardly extending bottom edge. In another embodiment, one or more dividing members are provided to divide the space within the inventive tray into one or more discrete compartments. Other unique features are described in the following description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion taken in conjunction with the following drawings, in which:
[0012] FIG. 1 is an isometric rendering of the storage member comprising the inventive tray;
[0013] FIG. 2 is an isometric view of the body of the storage member or tray showing various details of the tray body;
[0014] FIG. 3 is an isometric illustration of a removable front member of the tray;
[0015] FIG. 4 is a partial view of the fit up of the front member to an “L” shaped groove in a side member;
[0016] FIG. 5 is a partial view of the fit up of a tray dividing member to a “U” shaped groove in a side member;
[0017] FIG. 6 is an isometric drawing of one embodiment of the cover member;
[0018] FIG. 7 is an isometric drawing of another embodiment of the cover member;
[0019] FIG. 8 is a partial top view of the lockable feature of the cover and the tray body; and,
[0020] FIG. 9 is plan view of the rear of the tray and the attached cover.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention.
[0022] Reference is now made to the drawings, wherein like characteristics and features of the present invention shown in the various figures are designated by the same reference numerals.
[0023] Reference is now made to FIGS. 1 and 2 which comprise an isometric view of the inventive tray apparatus 10 comprising the tray body 11 having a cover 34 attached thereto, and an isometric view of the tray body 11 , respectively. The tray body 11 includes a bottom 12 , one side member 13 , an opposite side member 14 , and a back member 15 ; the back and side members being integrally attached to the bottom 12 along a horizontal edge thereof such that an open three sided box like structure is formed. The actual dimensions of the box-like structure are of course not critical to the invention. However, for purposes of explanation and as an example, the body 11 may be approximately 18 inches in depth, approximately 12 inches in width, and approximately five inches high. In a preferred embodiment, the box-like structure or body 11 , is formed from clear or transparent, rigid plastic that is injection molded in one piece. The transparency allows any objects stored in the inventive apparatus to be viewed without the necessity of having to open the tray 10 . In order to assist in automatic or machine assisted loading of a plurality of vials, ampoules or other such objects, it is preferable that the top surface of the bottom member 12 be provided with a friction reducing medium or a physical surface treatment such an embossment having rounded edges that allow vials or ampoules to easily slide there along when for example the vials or ampoules are mass loaded into a tray by a pushing technique.
[0024] It is preferred that the plastic material from which the body 11 of the tray 10 is made comprises injectable plastic, for example a polycarbonate, that is not filled with a material such as fiber glass or other particle generating filler. Non-filled injectable plastic completely eliminates the prior art problem of talc, glass, resin and metallic particles being generated by use, handling, transfer and decontamination of the tray. Additionally, injection molding allows for substantially parallel inside and outside surfaces of the walls of sides 13 , 14 and back member 15 of the tray 10 and substantial perpendicularity with the bottom member 12 . Such parallelism and perpendicularity further allows for close toleranced and convenient attachment of a front 28 A and intermediate or dividing 28 B panels and cover 34 to the tray body 11 that is important for safe storage and proper insertion and arranging of small diameter vials and ampoules within the tray 10 . The plastic material can also be specially adapted to accommodate different needs, e g. general storage trays, autocavable trays, and trays exposed to sub freezing temperatures. Suitable plastics include but are not limited to polyphenylsulfone and polycarbonate S X, the latter being available from the General Electric Company.
[0025] Plastic trays are preferred because of further advantages associated with plastic, i.e. it allows for color coding, allows for venting perforations that do not generate particles, and any plastic particles that are generated do not comprise medical contamination.
[0026] The tops of the side members 13 , 14 and the back member 15 are provided with a ledge 16 that extends around and internal to the side and back members and is located an appropriate distance below the top edges 17 of a rim 20 . (See FIG. 2 ) The ledge 16 stops a small distance from the front edges 25 of sides 13 and 14 so as to form a small lip or protruding member 21 that in combination with the rim 20 of the back member provides front to rear containment of another tray 10 when stacked on the ledge 16 of a first tray 10 . Side to side containment being obtained by inside edges of the rim 20 of sides 13 and 14 directly above the ledge 16 . The bottom of each tray 10 is configured to fit within the ledge 16 of another tray 10 such as by providing another rim or footer that fits within the rim 20 . The ledge 16 further provides a surface for fitting a cover member to the tray body 11 so as to completely enclose the tray 10 .
[0027] The top edges 17 of the rim 20 of the side members 13 , 14 can be provided with elongated members 18 that extend outwardly in the direction of top edge 17 for an appropriate distance and serve as handles to allow lifting or otherwise moving of the tray 10 . The back member 15 is likewise provided with an extending handle member 19 which is further provided with a slot or groove 22 at the approximate center of handle 19 , the bottom surface of the groove 22 being positioned to lie in the plane of the ledge 16 . An opening 23 is provided through the bottom surface of groove 22 within the extending portion of handle 19 .
[0028] Each side 13 and 14 is provided with a plurality of pairs of vertical grooves 24 (relative to the bottom member) spaced along the inner surface of each side 13 and 14 . Each groove 24 of each pair of grooves being located opposite each other such that the distance from the front edge 24 of sides 13 and 14 of each pair of grooves is the same. One or more of the grooves 24 can have an “L” shaped cross sectional configuration 24 A. Others can have “U” shaped cross sectional configuration 24 B. Preferably, the first one or two pairs of grooves 24 A, back from the front edges 25 of sides 13 and 14 , have the “L” configuration. The different configurations of grooves 24 A and 24 B are shown in FIG. 2 .
[0029] The grooves 24 A and 24 B do not extend to the bottom member 12 , but rather stop a short distance above the bottom member 12 where the bottom of the grooves intersect with the inside surface of sides 13 and 14 . The purpose of the non continual length of grooves 24 A and 24 B is to provide a flush surface directly below the grooves that comprises the interior surface of sides 13 and 14 . A flush surface is important when small vials or ampoules are being loaded into the tray 10 . In this way, the small vials or ampoules do not hang up within the grooves or are affected in their movement by the edges of the grooves.
[0030] FIG. 2 illustrates the outer surface of side 14 and applies equally to the outer side of side 13 . The wall of sides 13 and 14 are relatively thin and can approximately equal the width of ledge 16 and such that the rim 20 extends outward from the walls. A plurality of ribs 32 is provided at the location of the grooves 24 on the outside of sides 13 and 14 in order to provide stiffness to sides 13 and 14 and to maintain the relative thinness of the walls of sides 13 and 14 . In this manner, the tray body 11 is able to be made stiff but relatively light in weight. Moreover, the ribs 32 allow the depth of the grooves 24 to exceed the thickness of the walls of sides 13 and 14 . Additional reinforcing ribs can be provided at the corners of tray body 11 .
[0031] FIG. 3 shows a front member or panel 28 A that is preferably fitted to the grooves 24 A in sides 13 and 14 having the “L” shaped configuration. Front member 28 A is a separate part from tray body 11 . Front member 28 A is also clear or translucent and can be injection molded from a rigid type of plastic having features as described above. Front member 28 A essentially comprises a planer member having a pair of “U” shaped slots or grooves 29 in the front or back surface thereof and extend in a vertical direction and located at a small distance inward from the ends 31 . Front member 28 A is intended to be removably attached to the tray body 11 such that it forms the front side of the tray 10 . The bottom portion 30 of the ends 31 is cut away so as to effectively eliminate the groove 29 at the cut away portion 30 . Thus, grooves 29 do not extend to the bottom edge of front member 28 A but stop at the beginning of the cut away portion 30 . The combination of the non-grooved portion 30 and the non-continuous length of grooves 24 A allow the front member 28 A to be inserted in grooves 24 A and yet allow the bottom edge of front member 28 A to come in contact with and rest on the upper surface of tray bottom 12 . In other words the unique configuration of grooves 24 A and 29 allow the front panel 28 A to be inserted in grooves 24 A for the full height of the sides 13 and 14 and for the full height of front panel 28 A such that the top edge of front panel 28 A substantially lies in the plane of ledge 16 and the bottom edge of panel 28 A rests on the upper surface of bottom member 12 .
[0032] FIG. 4 illustrates a top view of the front panel 28 A fitted to an “L” shaped groove 24 A in a side member 13 or 14 . Although FIG. 4 illustrates such attachment as applied to one side 13 or 14 of tray body 11 , it is to be understood that the same attachment applies to the opposite side. In installing the front member 28 A, the “U” shaped grooves 29 of the front member 28 A are aligned with the “L” shaped grooves 24 A in the side members 13 and 14 and inserted in a downward direction until the bottom edge meets with the top surface of bottom member 12 . The interlocking fit up of the front member 28 A with the side members 13 and 14 , shown in FIG. 4 , results from the configurations 24 A and 29 of the respective grooves, and provides further structural rigidity to the tray 10 . While some clearance space is necessary between the interlocking grooves 24 A and 29 in order to assemble the two members, modern injection molding can allow for tight or close tolerances that provide for very small clearances such that upon assembly, a relatively rigid structure of the tray 10 is effectuated. Additional rigidity can be obtained by utilizing the same interlocking fit up by fitting a second removable panel 28 A in a second pair of “L” shaped grooves 24 A located an appropriate distance toward the back side of body 11 and spaced from the first panel 28 A.
[0033] One or more front to rear space dividing panels 28 B can be incorporated in the tray 10 . In a simpler embodiment, as partially shown in FIG. 5 , the dividing panels 28 B do not have the interlocking fit up as the front one or two panels 28 A. The dividing panels 28 B can simply comprise a planer member without any grooves that fit within the “U” shaped grooves 24 B in side members 13 and 14 . The “U” shaped grooves 24 B are also non-continuous in length as with the grooves 24 A. The dividing panels 28 B do however incorporate the cut away portion 30 in the same manner as per the front panel 28 A. Thus. as with the front panels 28 A, the top edge of the dividing panels 28 B lies in the plane of the ledge 16 when the dividing panels 28 B are fully inserted in the tray body 11 , and the bottom edge of the panel 28 B rests on the upper surface of tray bottom 12 .
[0034] The front to rear space between two interlocking panels 28 A, or an interlocking panel 28 A and a non-interlocking panel 28 B, can be further divided into side to side spaces by providing full length grooves 24 C in the front and or back surfaces of the panels 28 A and or 28 B. and inserting a plain panel 28 C in the grooves 24 C. The cross sectional configuration of grooves 24 C can either be the “L” or the “U” shaped configuration. Thus, the side to side dividing panels 28 C and the grooves 24 C do not incorporate the cut away portion 30 . Rather the side edges of panels 28 C and their respective grooves 24 C extend the full height of the panels.
[0035] The divided interior spaces in tray 10 are of course intended be used for storage and to allow separation of different types of vials and other medical paraphernalia. This feature allows for a plurality of separate compartments within a single tray 10 . For example, the divided spaces can be sized to fit vial receiving stands that contain vials in a particular order and location. Additional uses for the inventive tray 10 and the divided spaces can be readily envisioned.
[0036] Front panels or members 28 A and or dividing panels 28 b can be provided with one or more openings through the face of the panels. This feature is shown in phantom in FIG. 3 . The openings which can be square, rectangular or round, can allow for access into the tray 10 or its divided compartments when the front panel 28 A or dividing panels 28 B are inserted in place in to tray body 11 .
[0037] A cover 34 for the inventive tray 10 is shown in FIG. 6 . In one embodiment, the cover 34 A is preferably made from stainless steel sheet metal formed to include a planer top member 35 and a planar front member 36 The cover 34 A is appropriately dimensioned such that the top member 35 rests on the ledge 16 (provided at the top of the sides 13 and 14 and back members 15 ) and within the rim 20 , thereby covering the open top of tray body 11 while the front member 36 fits over the open front of tray body 11 . In this manner the inventive tray 10 is completely encased and any medical paraphernalia contained therein is free from possible contamination. In a further embodiment 34 B of a stainless steel cover, another planer member 37 extends a relatively short distance from the bottom of the front member 37 back in the direction of and parallel to top member 35 . The purpose of the backwardly extending planer member 37 is to fit under the front edge of the bottom 12 of tray body 11 so as to further secure the cover to the tray body 11 .
[0038] The width of the top member 35 of cover 34 A and 34 B is slightly smaller that the distance between the outside of ledges 16 and inside the rim 20 , so as to fit therebetween and rest thereon. In attaching the cover 34 A or 34 B to the tray body 11 , the top planer member 35 is inserted in slots 32 provided below the small lips 21 , which lips serve to comprise non-ledged portions of the front and top of the sides 13 and 14 of the tray body 11 , and then pushed rearward until contact is made with the rim 20 of the back member 15 . Both the slots 32 and the backwardly extending planer member 37 , serve to prevent the covers 34 A and 34 B from inadvertently being lifted off the tray body 11 . The cut outs 38 in the front of cover 34 A and 34 B provide clearance for the small lips 21 .
[0039] Yet another embodiment 34 C of the stainless steel cover 34 comprises a cover that is configured the same as a plastic cover 39 and attached to tray body 11 in the same manner as described below.
[0040] In another embodiment, a cover 34 D is made from a rigid transparent or translucent plastic as described above having a top planar member 40 that is generally configured the same as top member 35 of the stainless steel embodiments so as to provide a proper fit up with the tray body 11 . See FIG. 7 . In this embodiment 34 D, the front face 41 is provided with the “U” shaped grooves 29 and the cut away portions 30 as with the plastic front panel 28 A. Thus, the grooves 29 of the plastic cover 34 D fit within the “L” shaped grooves 24 A in the tray body 11 and in the same manner as the front plate member 28 A. In attaching the plastic cover 34 D to the tray body 11 , the front face member 39 is inserted in the “L” shaped grooves 24 A in each side member 13 and 14 and then lowered until the top member 40 rests on the ledges 16 . With the plastic cover embodiment, a front plate 28 A is not used. However, if it is desired to utilize a front plate member 28 A in addition to the front plate 41 of the plastic cover 34 D, a second pair of “L” shaped grooves 24 A can be provided in side members 13 and 14 a small distance from the first pair of “L” shaped grooves 24 A, back toward the back member 15 . The second pair of “L” shaped grooves 24 A is then used to fit the front plate member 28 A.
[0041] With all embodiments of the cover 34 , an extending tab 43 having a through opening 44 at the rearmost location of cover 34 or 38 is configured to fit with the slot or groove 22 provided in the back handle 19 of back member 15 when the cover 34 is placed on the tray body 11 . At this time, the through opening 44 in tab 43 aligns with the through opening 23 in the back handle 19 . In this manner when the cover 34 is placed on tray body 11 , a lock can be inserted in the openings 23 and 44 to prevent unauthorized entry into the covered tray 10 . Moreover, with the present invention and because of the location of the lockable feature, the lock does not interfere with stacking feature of the inventive trays 10 or otherwise interfere with the containment features of the tray 10 .
[0042] In a preferred embodiment the bottom external surface of bottom member 12 of tray body is provided with footer or rim that extends around the bottom member 12 and is indented a small distance so as to rest on and fit within the ledge 16 of another tray 10 . In this manner, one tray 10 can be stacked on another tray 10 with the footer of the upper tray 10 resting on and fitting within the ledges 16 of the lower tray 10 and, as explained above provides for front to rear and side to side containment of stacked trays 10 . In order to remove an intermediate tray 10 from a stack of trays 10 , it is a simple matter to slightly lift the upper tray or trays 10 to allow the intermediate tray 10 to clear the footer from the ledge 16 and allow the intermediate tray 10 to be removed from the stack.
[0043] In accordance with the above, an improved tray is disclosed that can be used as a standard in the fields of medicine, biotech, pharmaceuticals and others where the advantages of different types of plastic can be utilized to their fullest extent. Indeed, the versatility of the inventive tray fulfills the storage and handling needs of many fields including those requiring sterile conditions.
[0044] While the invention has been described, disclosed, illustrated and shown in certain terms or certain embodiments or modifications which it has assumed in practice, the scope of the invention is not intended to be nor should it be deemed to be limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the description of the invention and the drawings here appended. | Medical tray and cover apparatus includes a tray body having an open top and an open front; the cover is removable and covers the tray top and front. The tray body includes a plurality of oppositely disposed grooves that provide for the insertion of closure and divider panels. The tray grooves are configured to allow the tray to be loaded with ampoules or vials without being snagged by the grooves. The trays are transparent so that its contents are visible without removing the cover. The trays are stackable with the cover in place. The trays are lockable such that the ability to stack the trays is not interfered with. The tray and cover eliminate particle generation from use and wear that can contaminate the contents of the tray. The tray and cover are capable of being autoclaved. | 0 |
This application is a continuation of U.S. application Ser. No. 10/980,137, filed Nov. 1, 2004, now allowed, which is a divisional of U.S. application Ser. No. 10/125,106, filed Apr. 18, 2002, now U.S. Pat. No. 6,841,150, which is a continuation of U.S. application Ser. No. 09/573,989, filed May 17, 2000, now U.S. Pat. No. 6,429,013, which claims the benefit of priority under 35 U.S.C. §119 (e) to U.S. Provisional Patent Application 60/149,850, filed Aug. 19, 1999.
FIELD OF INVENTION
The present invention relates to methods and compositions for directing adipose-derived stromal cells cultivated in vitro to differentiate into cells of the chondrocyte lineage and particularly to such directed lineage induction prior to, or at the time of, their implantation into a recipient or host for the therapeutic treatment of pathologic conditions in humans and other species.
BACKGROUND OF THE INVENTION
Mesenchymal stem cells (MSCs) are the formative pluripotent blast or embryonic-like cells found in bone marrow, blood, dermis, and periosteum that are capable of differentiating into specific types of mesenchymal or connective tissues including adipose, osseous, cartilaginous, elastic, muscular, and fibrous connective tissues. The specific differentiation pathway which these cells enter depends upon various influences from mechanical influences and/or endogenous bioactive factors, such as growth factors, cytokines, and/or local microenvironmental conditions established by host tissues.
In prenatal organisms, the differentiation of MSCs into specialized connective tissue cells is well established; for example embryonic chick, mouse or human limb bud mesenchymal cells differentiate into cartilage, bone and other connective tissues (Caplan A I (1981) In: 39th Annual Symposium of the Society for Developmental Biology, ed by S. Subtelney and U Abbott, pp 3768. New York, Alan R Liss Inc; Elmer et al.(1981) Teratology, 24:215-223; Hauschka S. D. (1974) Developmental Biology (1974) 37:345-368; Solursh et al. (1981) Developmental Biology, 83:9-19; Swalla et. al. (1986) Developmental Biology, 116:31-38. In addition, a clonal rat fetus calvarial cell line has also been shown to differentiate into muscle, fat, cartilage, and bone (Goshima et al. (1991) Clin Orthop Rel Res. 269:274-283. The existence of MSCs in post-natal organisms has not been widely studied with the objective of showing the differentiation of post-embryonic cells into several mesodermal phenotypes. The few studies which have been done involve the formation of bone and cartilage by bone marrow cells following their encasement in diffusion chambers and in vivo transplantation (Ashton et al. (1980) Clin Orthop Rel Res, 151:294-307; Bruder et al.(1990) Bone Mineral, 11:141-151, 1990). Recently, cells from chick periosteum have been isolated, expanded in culture, and, under high density conditions in vitro, shown to differentiate into cartilage and bone (Nakahara et al. (1991) Exp Cell Res, 195:492-503). Rat bone marrow-derived mesenchymal cells have been shown to have the capacity to differentiate into osteoblasts and chondrocytes when implanted in vivo (Dennis et al.(1991) Cell Transpl, 1:2332; Goshima et al.(1991) Clin Orthop Rel Res. 269:274-283). Work by Johnstone et al. U.S. Pat. No. 5,908,784 has shown the ability of mesenchymal cells derived from skin to differentiate into cells biochemically and phenotypically similar to chondrocytes.
The adult bone marrow microenvironment is a potential source for these hypothetical mesodermal stem cells. Cells isolated from adult marrow are referred to by a variety of names, including stromal cells, stromal stem cells, mesenchymal stem cells (MSCs), mesenchymal fibroblasts, reticular-endothelial cells, and Westen-Bainton cells (Gimble et al. November 1996) Bone 19(5): 421-8). In vitro studies have determined that these cells can differentiate along multiple mesodermal or mesenchymal lineage pathways. These include, but are not limited to, adipocytes (Gimble, et al. (1992) J. Cell Biochem. 50:73-82, chondrocytes; Caplan, et al. (1998) J Bone Joint Surg. Am. 80(12):1745-57; hematopoietic supporting cells, Gimble, et al. (1992) J. Cell Biochem. 50:73-82; myocytes, Prockop, et al. (1999) J. Cell Biochem. 72(4):570-85; myocytes, Charbord, et al.(1999) Exp. Hematol. 27(12):1782-95; and osteoblasts, Beresford et al. (1993) J. Cell Physiol. 154:317-328). The bone marrow has been proposed as a source of stromal stem cells for the regeneration of bone, cartilage, muscle, adipose tissue, and other mesenchymal derived organs. The major limitations to the use of these cells are the difficulty and risk attendant upon bone marrow biopsy procedures and the low yield of stem cells from this source.
Adipose tissue offers a potential alternative to the bone marrow as a source of multipotential stromal stem cells. Adipose tissue is readily accessible and abundant in many individuals. Obesity is a condition of epidemic proportions in the United States, where over 50% of adults exceed the recommended BMI based-on their height. Adipocytes can be harvested by liposuction on an outpatient basis. This is a relatively non-invasive procedure with cosmetic effects that are acceptable to the vast majority of patients. It is well documented that adipocytes are a replenishable cell population. Even after surgical removal by liposuction or other procedures, it is common to see a recurrence of adipocytes in an individual over time. This suggests that adipose tissue contains stromal stem cells which are capable of self-renewal.
Pathologic evidence suggests that adipose-derived stromal cells are capable of differentiation along multiple mesenchymal lineages. The most common soft tissue tumor, liposarcomas, develop from adipocyte-like cells. Soft tissue tumors of mixed origin are relatively common. These may include elements of adipose tissue, muscle (smooth or skeletal), cartilage, and/or bone. Just as bone forming cells within the bone marrow can differentiate into adipocytes or fat cells, the extramedullary adipocytes are capable of forming osteoblasts (Halvorsen WO 99/28444).
Cartilage is a hyperhydrated structure with water comprising 70% to 80% of its weight. The remaining 20% to 30% comprises type II collagen and proteoglycan. The collagen usually accounts for 70% of the dry weight of cartilage (in “Pathology” (1988) Eds. Rubin & Farber, J. B. Lippincott Company, PA. pp. 1369-1371). Proteoglycans are composed of a central protein core from which long chains of polysaccharides extend. These polysaccharides, called glycosaminoglycans, include: chondroitin-4-sulfate, chondroitin-6-sulfate, and keratan sulfate. Cartilage has a characteristic structural organization consisting of chondrogenic cells dispersed within an endogenously produced and secreted extracellular matrix. The cavities in the matrix which contain the chondrocytes are called cartilage lacunae. Unlike bone, cartilage is neither innervated nor penetrated by either the vascular or lymphatic systems (Clemente (1984) in “Gray's Anatomy, 30. sup.th Edit,” Lea & Febiger).
Three types of cartilage are present in mammals and include: hyaline cartilage; fibrocartilage and elastic cartilage (Rubin and Farber, supra). Hyalne cartilage consists of a gristly mass having a firm, elastic consistency, is translucent and is pearly blue in color. Hyaline cartilage is predominantly found on the articulating surfaces of articulating joints. It is found also in epiphyseal plates, costal cartilage, tracheal cartilage, bronchial cartilage and nasal cartilage. Fibrocartilage is essentially the same as hyaline cartilage except that it contains fibrils of type I collagen that add tensile strength to the cartilage. The collagenous fibers are arranged in bundles, with the cartilage cells located between the bundles. Fibrocartilage is found commonly in the annulus fibrosis of the invertebral disc, tendinous and ligamentous insertions, menisci, the symphysis pubis, and insertions of joint capsules. Elastic cartilage also is similar to hyaline cartilage except that it contains fibers of elastin. It is more opaque than hyaline cartilage and is more flexible and pliant. These characteristics are defined in part by the elastic fibers embedded in the cartilage matrix. Typically, elastic cartilage is present in the pinna of the ears, the epiglottis, and the larynx.
The surfaces of articulating bones in mammalian joints are covered with articular cartilage. The articular cartilage prevents direct contact of the opposing bone surfaces and permits the near frictionless movement of the articulating bones relative to one another (Clemente, supra). Two types of articular cartilage defects are commonly observed in mammals and include full-thickness and partial-thickness defects. The two-types of defects differ not only in the extent of physical damage but also in the nature of repair response each type of lesion elicits.
Full-thickness articular cartilage defects include damage to the articular cartilage, the underlying subchondral bone tissue, and the calcified layer of cartilage located between the articular cartilage and the subchondral bone. Full-thickness defects typically arise during severe trauma of the joint or during the late stages of degenerative joint diseases, for example, during osteoarthritis. Since the subchondral bone tissue is both innervated and vascularized, damage to this tissue is often painful. The repair reaction induced by damage to the subchondral bone usually results in the formation of fibrocartilage at the site of the full-thickness defect. Fibrocartilage, however, lacks the biomechanical properties of articular cartilage and fails to persist in the joint on a long term basis.
Partial-thickness articular cartilage defects are restricted to the cartilage tissue itself. These defects usually include fissures or clefts in the articulating surface of the cartilage. Partial-thickness defects are caused by mechanical arrangements of the joint which in turn induce wearing of the cartilage tissue within the joint. In the absence of innervation and vasculature, partial-thickness defects do not elicit repair responses and therefore tend not to heal. Although painless, partial-thickness defects often degenerate into full-thickness defects.
In accordance with the present invention it has been observed by the inventors that when human adipose tissue-derived stromal cells are associated in a three-dimensional format they can be induced to commit and differentiate along the chondrogenic pathway when contacted in vitro with certain chondroinductive agents or factors. The three dimensional format is critical to the in vitro chondrogenesis of the invention and the cells are—preferably condensed together, for example, as a packed or pelleted cell mass or in an alginate matrix. This invention presents examples of methods and composition for the isolation, differentiation, and characterization of adult human extramedullary adipose tissue stromal cells along the chondrocyte lineage and outlines their use for the treatment of a number of human conditions and diseases. This in vitro process is believed to recapitulate that which occurs in vivo and can be used to facilitate repair of cartilage in vivo in mammals.
SUMMARY OF INVENTION
The present invention provides methods and composition for consistent and quantitative induction of stromal cells derived from subcutaneous, mammary, gonadal, or omental adipose tissues into fully functional chondrocytes. The methods comprise incubation of isolated adipose tissue-derived stromal cells, plated at densities of 500 to 20,000 cells/cm 2 in a chemically defined culture medium having or supplemented with (1) a chondroinductive agent that can activate any cellular transduction pathway leading to the mature chondrocyte phenotype; (2) an antibiotic; (3) a nutrient supplement such as fetal bovine serum or horse serum; (4) ascorbate or related vitamin C analogue; and (5) a glucocorticoid or another chemical agent capable of activating the cellular glucocorticoid receptor.
The present invention also provides a method for differentiating adipose tissue derived stromal cells into chondrocytice cells by pelleting stromal cells in medium such as DMEM or alpha-MEM or RPMI 1640 and supplementing the medium with (1) a chondroinductive agent that can activate any cellular transduction pathway leading to the mature chondrocyte phenotype; (2) an antibiotic; (3) a nutrient supplement such as fetal bovine serum or horse serum; (4) ascorbate or related vitamin C analogue; and (5) a glucocorticoid or another chemical agent capable of activating the cellular glucocorticoid receptor.
The present invention also provides a method for differentiating adipose tissue derived stromal cells into chondrocytic cells by suspending the cells in a calcium alginate or other biocompatible lattice or matrix capable of supporting chondrogenesis in a three dimensional configuration.
The present invention provides methods for determining the ability of these culture conditions and agents to direct the differentiation and function of the adipose tissue-derived stromal cells, for the transduction of viral vectors carrying regulatory genes into the stromal cells, for the transfection of plasmid vectors carrying regulatory genes into the stromal cells, for the tracking and detection of functional proteins encoded by these genes, and for developing biomechanical carriers for the re-introduction of these cells into a living organism.
This invention further provides methods for the introduction of these chondrocytes into cartilage defect areas for repair.
The methods and composition have use in drug discovery for compounds and proteins with relevance to the differentiated cell-related disease states and traumatic injuries including but not limited to: anterior crucia ligament tears, full-thickness articular cartilage defects, partial-thickness articular cartilage defects.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the immunodetection of collagen type II in human adipose stromal cells from monolayer cultures. Phase contrast microscopy is used in the upper panel; Immunofluorescence is used in the lower panel.
FIG. 2 shows immunodetection of collagen type II in human adipose stromal cells from pellet cultures. Phase contrast microscopy is used in the upper panel; Immunofluorescence is used in the lower panel.
FIG. 3 shows immunodetection of collagen type II in human adipose stromal cells from alginate cultures. Phase contrast microscopy is used in the upper panel; Immunofluorescence is used in the lower panel.
FIG. 4 shows Collagen type VI expression when cells were cultured in an alginate matrix at 2 weeks without TGF-beta (control) and with TGF-beta.
FIG. 5 shows a Western blot of results when cells were grown as monolayers or in an alginate suspension for the expression of different proteins including: collagen type VI, link, aggrecan, collagen type I, and actin.
DETAILED DESCRIPTION OF INVENTION
The present invention provides methods and a composition for the differentiation and culture of adipose tissue-derived stromal cells into chondrocytes. The cells produced by the methods of invention are useful in providing a source of fully differentiated and functional cells for research, transplantation, and development of tissue engineering products for the treatment of human disease and traumatic injury repair. Thus, in one aspect, the invention provides a method for differentiating adipose tissue-derived stromal cells into chondrocytes comprising culturing stromal cells in a composition which comprises a medium capable of supporting the growth and differentiation of stromal cells into functional chondrocytes. This invention further provides methods for the introduction of these chondrocytes into cartilage defect areas for repair.
“Adipose stromal cells” refers to stromal cells that originate from adipose tissue. By “adipose” is meant any fat tissue. The adipose tissue may be brown or white adipose tissue, derived from subcutaneous, omental/visceral, mammary, gonadal, or other adipose tissue site. Preferably, the adipose is subcutaneous white adipose tissue. Such cells may comprise a primary cell culture or an immortalized cell line. The adipose tissue may be from any organism having fat tissue. Preferably, the adipose tissue is mammalian, most preferably the adipose tissue is human. A convenient source of adipose tissue is from liposuction surgery, however, the source of adipose tissue or the method of isolation of adipose tissue is not critical to the invention. If stromal cells are desired for autologous transplantation into a subject, the adipose tissue will be isolated from that subject.
“Chondrocytes (cartilage cells)” refers to cells that are capable of expressing characteristic biochemical markers of chondrocytes, including but not limited to collagen type II, chondroitin sulfate, keratin sulfate and characteristic morphologic markers of smooth muscle, including but not limited to the rounded morphology observed in culture, and able to secrete collagen type II, including but not limited to the generation of tissue or matrices with hemodynamic properties of cartilage in vitro.
Any medium capable of supporting stromal cells in tissue culture may be used. Media formulations that will support the growth of fibroblasts include, but are not limited to, Dulbecco's Modified Eagle's Medium (DMEM), alpha modified Minimal Essential Medium (αMEM), and Roswell Park Memorial Institute Media 1640 (RPMI Media 1640) and the like. Typically, 0 to 20% Fetal Bovine Serum (FBS) or 1-20% horse serum will be added to the above media in order to support the growth of stromal cells and/or chondrocytes. However, a defined medium could be used if the necessary growth factors, cytokines, and hormones in FBS for stromal cells and chondrocytes are identified and provided at appropriate concentrations in the growth medium. Media useful in the methods of the invention may contain one or more compounds of interest, including, but not limited to antibiotics mitogenic or differentiative compounds for stromal cells. The cells will be grown at temperatures between 31° C. to 37° C. in a humidified incubator. The carbon dioxide content will be maintained between 2% to 10% and the oxygen content between 1% and 22%. Cells will remain in this environment for periods of up to 4 weeks.
Antibiotics which can supplemented into the medium include, but are not limited to penicillin and streptomycin. The concentration of penicillin in the chemically defined culture medium is about 10 to about 200 units per ml. The concentration of streptomycin in the chemically defined culture medium is about 10 to about 200 ug/ml.
Glucocorticoids that can be used in the invention include but are not limited to hydrocortisone and dexamethasone. The concentration of dexamethasone in the medium is about 1 to about 100 nM. The concentration of hydrocortisone in the medium is about 1 to about 100 nM.
As used herein the terms “chondroinductive agent” or “chondroinductive factor” refers to any natural or synthetic, organic or inorganic chemical or biochemical compound or combination or mixture of compounds, or any mechanical or other physical device, container, influence or force that can be applied to human adipose tissue-derived stromal cells so as to effect their in vitro chondrogenic induction or the production of chondrocytes. The chondroinductive agent is preferably selected, individually or in combination, from the group consisting of (i) a glucocorticoid such as dexamethasone; (ii) a member of the transforming growth factor-β superfamily such as a bone morphogenic protein (preferably BMP-2 or BMP-4), TGF-β1, TGF-β2, TGF-β3, insulin-like growth factor (IGF), platelet derived growth factor (PDGF), epidermal growth factor (EGF), acidic fibroblast growth factor (aFBF), basic fibroblast growth factor (bFBF), hepatocytic growth factor (HGF), keratocyte growth factor (KGF), osteogenic proteins (OP-1, OP-2, and OP-3), inhibin A or chondrogenic stimulating activity factor (CSA); (iii) a component of the collagenous extracellular matrix such as collagen I (particularly in the form of a gel); and (iv) a vitamin A analogue such as retinoic acid and; (v) ascorbate or other related vitamin C analogue.
The concentration of transforming growth factor-beta is about 1 to about 100 ng/ml. The concentration of retinoic acid is about 0.1 to about 1 ug/ml.
Examples of compounds that are stromal cell mitogens include but are not limited to transforming growth factor β; fibroblast growth factor, bone morphogenetic protein and stromal cell differentiating factors include but are not limited to dexamethasone, hydrocortisone, transforming growth factor β, fibroblast growth factor, and bone morphogenetic protein and the like.
Preferably, the adipose tissue derived stromal cells are isolated from the adipose tissue of the subject into which the final differentiated cells are to be introduced. However, the stromal cells may also be isolated from any organism of the same or different species as the subject. Any organism with adipose tissue can be a potential candidate. Preferably, the organism is mammalian, most preferably the organism is human.
The present invention also provides a method for differentiating adipose derived stromal cells into chondrocytic cells by suspending the cells in a calcium alginate or another biocompatible lattice or matrix capable of supporting chondrogenesis in a three dimensional configuration. Examples of lattice materials include (1) calcium alginate, a polysaccharide of cross linked L-glucuronic and D-mannuronic acid, at concentrations of between 1% to 4%; (2) fibrin; (3) collagen type II; or (4) agarose gel. The lattices or matrixes containing the cells are transferred to culture dishes containing: (1) a chondroinductive agent that can activate any cellular transduction pathway leading to the mature chondrocyte phenotype; (2) an antibiotic; (3) a nutrient supplement such as fetal bovine serum or horse serum; (4) ascorbate or related vitamin C analogue; and (5) a glucocorticoid or another chemical agent capable of activating the cellular glucocorticoid receptor.
The adipose tissue derived stromal cells may be stably or transiently transfected or transduced with a nucleic acid of interest using a plasmid, viral or alternative vector strategy. Nucleic acids of interest include, but are not limited to, those encoding gene products which enhance the production of extracellular matrix components found in cartilage; examples include transforming growth factor β, bone morphogentic protein, activin and insulin-like growth factor.
The transduction of viral vectors carrying regulatory genes into the stromal cells can be performed with viral vectors (adenovirus, retrovirus, adeno-associated virus, or other vector) purified by cesium chloride banding or other method at a multiplicity of infection (viral units:cell) of between 10:1 to 2000:1. Cells will be exposed to the virus in serum free or serum-containing medium in the absence or presence of a cationic detergent such as polyethyleneimine or Lipofectamine™ for a period of 1 hour to 24 hours (Byk T. et al. (1998) Human Gene Therapy 9:2493-2502; Sommer B. et al. (1999) Calcif. Tissue Int. 64:45-49).
The transfection of plasmid vectors carrying regulatory genes into the stromal cells can be introduced into the cells in monolayer cultures by use of calcium phosphate DNA precipitation or cationic detergent methods (Lipofectamine™, DOTAP) or in three dimensional cultures by incorporation of the plasmid DNA vectors directly into the biocompatible polymer (Bonadio J. et al. (1999) Nat. Med. 5:753-759).
For the tracking and detection of functional proteins encoded by these genes, the viral or plasmid DNA vectors will contain a readily detectable marker gene, such as the green fluorescent protein or beta-galactosidase enzyme, both of which can be tracked by histochemical means.
For the development of biomechanical carriers for the re-introduction of the stromal cells into a living organism, the carriers include but are not limited to calcium alginate, agarose, types I, II, IV or other collagen isoform, fibrin, poly-lactic/poly-glycolic acid, hyaluronate derivatives or other materials (Perka C. et al. (2000) J. Biomed. Mater. Res. 49:305-311; Sechriest V F. et al. (2000) J. Biomed Mater. Res. 49:534-541; Chu C R et al. (1995) J. Biomed Mater. Res. 29:1147-1154; Hendrickson D A et al. (1994) Orthop. Res. 12:485-497).
Another object of the invention is to provide for the identification and study of compounds that enhance the differentiation of adipose tissue derived stromal cells into chondrocytes. Compounds which enhance differentiation may be of value in the treatment of partial or full cartilage defects, osteoarthritis, traumatized cartilage, cosmetic surgery of inborn defects including cleft palate or deviated septum. Methods include but are not limited to the development of three-dimensional in vitro cultures maintaining adipose tissue-derived stromal cells as chondrocytes that can be subsequently exposed to novel compounds of interest.
Any compound may be tested for its ability to affect the differentiation of adipose tissue derived stromal cells into chondrocytes. Appropriate vehicles compatible with the compound to be tested are known to those skilled in the art and may be found in the current edition of Remington's Pharmaceutical Sciences (1995, Mack Publishing Co., Easton, Pa.) the contents of which are incorporated herein by reference.
The features and advantages of the present invention will be more clearly understood by reference to the following examples, which are not to be construed as limiting the invention.
EXPERIMENTAL
Differentiation of Adipose Tissue-Derived Stromal Cells into Chondrocytes
Example 1
In Vitro Chondrogenesis Using Dexamethasone
Stromal cells are isolated from human subcutaneous adipose tissue according to methods described in “ Methods and Composition of the Differentiation of Human Preadipocytes into Adipocytes ” Ser. No. 09/240,029 Filed Jan. 29, 1999. These cells are plated at a density of 500 to 20,000 cells per cm 2 . The present invention contemplates that the creation of a precartilage condensation in vitro promotes chondrogenesis in mesenchymal progenitor cells derived from human adipose tissue. This is accomplished by methods including, but not limited to:
(1) The pellet culture system, which was developed for use with isolated growth plate cells (Kato et al. (1988) PNAS 85:9552-9556; Ballock & Reddi, J. Cell Biol . (1994) 126(5):1311-1318) and has been used to maintain expression of the cartilage phenotype of chondrocytes placed in culture (Solursh (1991) J. Cell Biochem. 45:258-260). (2) The alginate suspension method, where cells are maintained in a calcium alginate suspension to prevent cell-cell contact and maintain a characteristic rounded morphology promoting the maintenance or acquisition of the chondrocyte phenotype.
Human adipose tissue-derived cells are isolated as described above. For pellet cultures, aliquots of 200,000 cells were centrifuged at 500 g for 10 minutes in sterile 15 ml conical polypropylene tubes in DMEM with 10% fetal bovine serum, 50 ng/rl ascorbate-2-phosphate, 100 nM dexamethasone (DEX) and then incubated at 37° C. in a 5% CO 2 incubator for up to 3 weeks. For alginate cultures, cells were suspended at a density of 1 million cells per ml in 1.2% calcium alginate and maintained in DMEM with 10% fetal bovine serun, 50 ng/ml ascorbate-2-phosphate, 100 nM dexamethasone (DEX) and then incubated at 37° C. in a 5% CO 2 incubator for up to 3 weeks. After 2 or 4 weeks, the cells were isolated, fixed and analyzed for chondrocyte lineage markers by immunohistochemistry with appropriate antibody reagents or by staining with toluidine blue to detect the presence of sulfated proteoglycans in the extracellular matrix.
Results obtained with an antibody detecting a representative chondrocyte marker protein, collagen II, are shown in FIGS. 1-3 . The cells maintained in pellet culture ( FIG. 2 ) or calcium alginate ( FIG. 3 ) stained positive by immunofluorescence for the intracellular presence of the collagen II protein. These results are to be contrasted with identical analysis of adipose tissue-derived cells maintained for 3 weeks in monolayer culture as shown in FIG. 1 ; here, no staining whatsoever is observed. Immunohistochemical results with an antibody reagent detecting the chondrocyte marker protein, collagen VI, are shown in FIG. 4 . Adipose tissue-derived stromal cells were maintained in 1.2% calcium alginate and maintained in DMEM with 10% fetal bovine serum, 50 ng/ml ascorbate-2-phosphate, 100 nM dexamethasone (DEX) in the absence or presence of transforming growth factor β (10 ng/ml) and then incubated at 37° C. in a 5% CO 2 incubator for up to 2 weeks. Immunohistochemistry revealed a dense deposition of the collagen VI protein surrounding those cells maintained in the presence, but not the absence, of transforming growth factor β.
Polymerase chain reaction results detecting representative gene markers associated with chondrogenesis are shown in FIG. 5 . Adipose tissue-derived stromal cells were maintained in 1.2% calcium alginate (Alg) or in monolayer (Mono) cultures and maintained in DMEM with 10% fetal bovine serum, 50 ng/ml ascorbate-2-phosphate, 100 nM dexamethasone (DEX) in the absence (TGFβ−) or presence (TGFβ+) of transforming growth factor β (10 ng/ml) for a period of 4 weeks. Total RNA was isolated from the individual cultures and used in polymerase chain reactions with primers specific for collagens types I or VI, the proteoglycan link (Link) protein, aggrecan, or actin. The collagen markers and actin were detected under all growth conditions. However, the link mRNAs were most abundant under alginate suspension conditions and aggrecan was only present under alginate conditions in the presence of TGFβ.
These results demonstrate that, through a combination of creating an in vitro cell condensation and adding the appropriate permissive factors, we are able to produce the expression of chondrocyte markers consistent with chondrogenesis in cells from subcutaneous adipose tissue.
Example 2
Preparation of Synthetic Cartilage Patch
Following proliferation, the chondrogenic cells still having chondrogenic potential may be cultured in an anchorage-independent manner, i.e., in a well having a cell contacting, cell adhesive surface, in order to stimulate the secretion of cartilage-specific extracellular matrix components.
Heretofore, it has been observed that chondrogenic cells proliferatively expanded in an anchorage-dependent manner usually dedifferentiate and lose their ability to secrete cartilage-specific type II collagen and sulfated proteoglycan. (Mayne et al. (1984) Exp. Cell. Res. 151(1): 171-82; Mayne et al. (1976) PNAS 73(5): 1674-8; Okayama et al. (1976) PNAS 73(9):3224-8; Pacifici et al. (1981) J. Biol Chem. 256(2): 1029-37; Pacifici et al. (1980) Cancer Res. 40(7): 2461-4; Pacifici et al. (1977) Cell 4: 891-9; von der Mark et al. (1977) Nature 267(5611):531-2; West et al. (1979) Cell 17(3):491-501; Oegama et al. (1981) J. Biol. Chem. 256(2):1015-22; Benya et al. (1982) Cell 30(1):215-24).
It has been discovered that undifferentiated chondrogenic cells, when seeded into, and cultured in a well having a cell contacting surface that discourages adhesion of cells to the cell contacting surface, the cells redifferentiate and start to secrete cartilage-specific collagen and sulfated proteoglycans thereby to form a patch of synthetic cartilage in vitro (U.S. Pat. Nos. 5,902,741 and 5,723,331).
In addition, it has been found that culturing the cells in a pre-shaped well, enables one to manufacture synthetic cartilage patches of pre-determined thickness and volume. It is appreciated, however, that the volume of the resulting patch of cartilage is dependent not only upon the volume of the well but also upon the number of chondrogenic cells seeded into the well. Cartilage of optimal pre-determined volume may be prepared by routine experimentation by altering either, or both of the aforementioned parameters.
A. Preparation of Pre-shaped Well.
Several approaches are available for preparing pre-shaped wells with cell contacting, cell adhesive surfaces.
The cell contacting surface of the well may be coated with a molecule that discourages adhesion of chondrogenic cells to the cell contacting surface. Preferred coating reagents include silicon based reagents i.e., dichlorodimethylsilane or polytetrafluoroethylene based reagents, i.e., Teflon® Procedures for coating materials with silicon based reagents, specifically dichlorodimethylsilane, are well known in the art. See for example, Sambrook et al. (1989) “Molecular Cloning A Laboratory Manual”, Cold Spring Harbor Laboratory Press, the disclosure of which is incorporated by reference herein. It is appreciated that other biocompatible reagents that prevent the attachment of cells to the surface of the well may be useful in the practice of the instant invention.
Alternatively, the well may be cast from a pliable or moldable biocompatible material that does not permit attachment of cells per se. Preferred materials that prevent such cell attachment include, but are not limited to, agarose, glass, untreated cell culture plastic and polytetrafluoroethylene, i.e., Teflon® Untreated cell culture plastics, i.e., plastics that have not been treated with or made from materials that have an electrostatic charge are commercially available, and may be purchased, for example, from Falcon Labware, Becton-Dickinson, Lincoln Park, N.J. The aforementioned materials, however, are not meant to be limiting. It is appreciated that any other pliable or moldable biocompatible material that inherently discourages the attachment of chondrogenic cells may be useful in the practice of the instant invention.
The size and shape of the well may be determined by the size and shape of the articular cartilage defect to be repaired. For example, it is contemplated that the well may have a cross-sectional surface area of 25 cm.sup.2. This is the average cross-sectional surface area of an adult, human femoral chondyle. Accordingly, it is anticipated that a single piece of synthetic cartilage may be prepared in accordance with the invention in order to resurface the entire femoral chondyle. The depth of the well is preferably greater than about 0.3 cm and preferably about 0.6 cm in depth. The thickness of natural articular cartilage in an adult articulating joint is usually about 0.3 cm. Accordingly, the depth of the well should be large enough to permit a cartilage patch of about 0.3 cm to form. However, the well should also be deep enough to contain growth medium overlaying the cartilage patch.
It is contemplated also that a large piece of cartilage prepared in accordance with the invention may be “trimmed” to a pre-selected size and shape by a surgeon performing surgical repair of the damaged cartilage. Trimming may be performed with the use of a sharp cutting implement, i.e., a scalpel, a pair of scissors or an arthroscopic device fitted with a cutting edge, using procedures well known in the art.
The pre-shaped well preferably is cast in a block of agarose gel under aseptic conditions. Agarose is an economical, biocompatible, pliable and moldable material that can be used to cast pre-shaped wells, quickly and easily. As mentioned above, the dimensions of the well may dependent upon the size of the resulting cartilage plug that is desired.
A pre-shaped well may be prepared by pouring a hot solution of molten LT agarose (BioRad, Richmond, Calif.) into a tissue culture dish containing a cylinder. The cylinder having dimensions that mirror the shape of the well to be formed. The size and shape of the well may be chosen by the artisan and may be dependent upon the shape of the articular cartilage defect to be repaired. Once the agarose has cooled and solidified around the cylinder, the cylinder is carefully removed with forceps. The surface of the tissue culture dish that is exposed by the removal of the cylinder is covered with molten agarose. This seals the bottom of the well and provides a cell adhesive surface at the base of the well. When the newly added molten LT agarose cools and solidifies, the resulting pre-shaped well is suitable for culturing, and stimulating the redifferentiation of proliferated chondrogenic cells. It is appreciated, however, that alternative methods may be used to prepare a pre-shaped well useful in the practice of the invention.
B. Growth of Cartilage Patch.
Proliferated chondrogenic cells in suspension may be seeded into and cultured in the pre-shaped well. The cells may be diluted by the addition of cell culture medium to a cell density of about 1×10 5 to 1×10 9 chondrogenic cells per ml. A preferred cell culture medium comprises DMEM supplemented with 10% fetal bovine serum.
Within about four hours of seeding the chondrogenic cells into the well, the cells may coalesce to form a cohesive plug of cells. After about 4-10 days, the cells will start to secrete cartilage-specific sulfated proteoglycans and type II collagen. After prolonged periods of time in culture the collagen expressed by the chondrogenic cells in the well will be predominantly type II collagen. It is contemplated however, that the cohesive plug of cells formed within four hours may be removed from the well and surgically implanted into the cartilage defect. It is anticipated that the undifferentiated chondrogenic cells subsequently may redifferentiate in situ thereby to form synthetic cartilage within the joint.
It is contemplated that chondrocytic differentiation or stimulatory factors may be added to the chondrogenic cells in the pre-shaped well to enhance or stimulate the production of articular cartilage specific proteoglycans and/or collagen (Luyten & Reddi (1992) in “Biological Regulation of the Chondrocytes”, CRC Press, Boca Raton, Ann Arbor, London, and Tokyo, p.p. 227-236). Preferred growth factors include, but are not limited to transforming growth factor-β (TGF-β), insulin-like growth factor (IGF), platelet derived growth factor (PDGF), epidermal growth factor (EGF), acidic fibroblast growth factor (aFBF), basic fibroblast growth factor (bFBF), hepatocytic growth factor; (HGF) keratinocyte growth factor (KGF), the bone morphogenic factors (BMPs) i.e., BMP-1, BMP-2, BMP-3, BMP-4, BMP-5 and BMP-6 and the osteogenic proteins (OPs), i.e. OP-1, OP-2 and OP-3. Preferred concentrations of TGF-β, IGF, PDGF, EGF, aFBF, bFBF, HGF, and KGF, range from about 1 to 100 ng/ml. Preferred concentrations of the BMP's and OP's range from about 1 to about 500 ng/ml.
However, these particular growth factors are not limiting. Any polypeptide growth factor capable of stimulating or inducing the production of cartilage specific proteoglycans and collagen may be useful in the practice of the instant invention.
In addition, it is contemplated that ascorbate may be added to the chondrogenic cells in the pre-shaped well to enhance or stimulate the production of cartilage specific proteoglycans and collagen. Preferred concentrations of ascorbate range from about 1 to about 1000 g/ml.
Example 3
Surgical Repair of Articular Cartilage Defect
Cartilage defects in mammals are readily identifiable visually during arthroscopic examination or during open surgery of the joint. Cartilage defects may also be identified inferentially by using computer aided tomography (CAT scanning), X-ray examination, magnetic resonance imaging (MRI), analysis of synovial fluid or serum markers or by any other procedures known in the art. Treatment of the defects can be effected during an arthroscopic or open surgical procedure using the methods and compositions disclosed herein.
Accordingly, once the defect has been identified, the defect may be treated by the following steps of (1) surgically implanting at the predetermined site, a piece of synthetic articular cartilage prepared by the methodologies described herein, and (2) permitting the synthetic articular cartilage to integrate into pre-determined site.
The synthetic cartilage patch optimally has a size and shape such that when the patch is implanted into the defect, the edges of the implanted tissue contact directly the edges of the defect. In addition, the synthetic cartilage patch may be fixed in placed during the surgical procedure. This can be effected by surgically fixing the patch into the defect with biodegradable sutures, i.e., (Ethicon, Johnson & Johnson) and/or by applying a bioadhesive to the region interfacing the patch and the defect. Preferred bioadhesives include, but are not limited to: fibrin-thrombin glues similar to those disclosed in Fr. Pat. No. 2 448 900; Fr. Pat. No. 2 448 901 and EP.S.N. 88401961.3 and synthetic bioadhesives similar to those disclosed in U.S. Pat. No. 5,197,973. It is contemplated, however, that alternative types of sutures and biocompatible glues may be useful in the practice of the invention
In some instances, damaged articular cartilage maybe surgically excised prior the to implantation of the patch of synthetic cartilage. Additionally, the adhesion of the synthetic cartilage patch to the articular cartilage defect may be enhanced by treating the defect with transglutaminase (Ichinose et al. (1990) J. Biol. Chem. 265(3):13411-13414; Najjar et al. (1984) in “Transglutaminases”, Boston, Martinuse-Nijhoff). Initially, the cartilage defect is dried, for example by using cottonoid, and filled with a solution of transglutaminase. The solution is subsequently removed, for example, by aspiration, leaving a film containing transglutaminase upon the cartilage. The synthetic cartilage patch is implanted subsequently into the defect by the methods described above.
In addition the synthetic cartilage may be useful in the repair of human articular cartilage defects. Accordingly, chondrogenic cells may be differentiated from human adipose tissue-derived stromal cells, i.e, human subcutaneous adipose tissue.
Surgical procedures for effecting the repair of articular cartilage defects are well known in the art. See for example: Luyten & Reddi (1992) in “Biological Regulation of the Chondrocytes”, CRC Press, Boca Raton, Ann Arbor, London, & Tokyo, p.p. 227-236, the disclosure of which is incorporated by reference herein.
The above demonstrates a culture system in which human adipose tissue-derived stromal cells differentiate into hypertrophic chondrocytes. Since all components are defined, the system can be used for studies of the effects of growth factors etc. on the progression of chondrogenesis. In vitro systems have been used by us and others to show that these cell populations have osteogenic and adipocytic potential. We demonstrate here that this population has chondrogenic potential. This has clinical applicability for cartilage repair.
The invention also provides a process for inducing chondrogenesis in human adipose tissue-derived stromal cells by contacting such cells with a chondroinductive agent in vitro where the stromal cells are associated in a three dimensional format.
The invention also provides a process for using in vitro differentiated chondrocytes from adipose-derived stromal cells in the repair of cartilage tissue in mammals, including humans.
In the above methods, the stromal cells are preferably isolated, culture expanded human adipose tissue-derived stromal cells in a chemically defined environment and are condensed into close proximity, such as in the form of a three dimensional cell mass, e.g. packed cells or a centrifugal cell pellet. Further, the contacting preferably comprises culturing a pellet of human adipose tissue-derived stromal cells in a chemically defined medium which comprises DMEM with 10% serum, 50 ng/ml ascorbate-2-phosphate, 10 −7 M dexamethasone. The differentiated cells are then introduced into the surgery site to repair cartilage. Since all components of the system are defined, the system can be used as a product for cartilage repair in mammals, including man and horses. | Methods and compositions for directing adipose-derived stromal cells cultivated in vitro to differentiate into cells of the chondrocyte lineage are disclosed. The invention further provides a variety of chondroinductive agents which can be used singly or in combination with other nutrient components to induce chondrogenesis in adipose-derived stromal cells either in cultivating monolayers or in a biocompatible lattice or matrix in a three-dimensional configuration. Use of the differentiated chondrocytes for the therapeutic treatment of a number of human conditions and diseases including repair of cartilage in vivo is disclosed. | 2 |
BACKGROUND OF THE INVENTION
The invention relates generally to control systems for controlling the cyclical motion of fluidically driven members. More specifically, the invention relates to a control system for controlling straight-line shear for cutting gobs from a stream of molten glass in a glassware forming machine.
The use of shears for cutting gobs from a stream of molten glass falling from a feeder of a glassware forming machine is well-known in the prior art. Such shears are generally of either the arcuate or straight-line type, each type having a cyclically oscillating single pair of opposed blades associated with a single stream of molten glass. An example of a prior art double gob shear assembly of the straight-line type is shown in U.S. Pat. No. 4,174,647, dated Nov. 20, 1979, and assigned to the assignee of the present invention. Prior art shears are generally activated by pneumatic (or fluidic) means interconnected in a complex arrangement of various valves and cylinders.
The present invention relates to an improvement over the prior art control system of commonly assigned U.S. Pat. No. 4,467,431, the disclosure of which is incorporated by reference herein. Such patent discloses a control system for pneumatically driven straight-line shears (such as shears of the type disclosed in the U.S. Pat. No. 4,174,647 patent cited above), such control system incorporating a series of sensors which produce signals representing predetermined shear positions in each shear cycle. As illustrated in FIGS. 5 and 6 at the U.S. Pat. No. 4,467,431 and the text discussing these Figures, such prior art system incorporates four sensors--a return delay sensor, a zero crossover sensor, an overlap sensor, and a cushion sensor, each of which produces an output signal at a predetermined point of the travel of the shears, for controlling various aspects of the shears' operation in accordance with the method disclosed therein. The shears are pneumatically driven in the forward (cutting) and reverse direction by selectively energizing and deenergizing (or reversing) the cylinder assembly of FIG. 3. The timing of this energization and deenergization, and hence the motion profile of the shears, is determined by the timing of the return sensor and overlap sensor signals, as well as by a return delay time which is added to the return sensor signal to determine the off time of the shears' pneumatic drive.
As illustrated in FIGS. 6 and 7 of the U.S. Pat. No. 4,467,431 and discussed at column 6, lines 17 and following, the return delay time is calculated by a circuit which incorporates an up/down counter, the count from which decrements or increments as a function of the overlap signal from the previous cycle. When an overlap sensor signal occurs (signifying that the shears have travelled at least as far as such sensor), a "count down" command is produced causing the return delay time to be decremented; the converse happens if such sensor is not triggered in the previous cycle. Although this system provided excellent performance as compared with prior art shears control systems, the continual incrementing and decrementing of the return delay time has imposed a limitation on the accuracy with which shears travel could be controlled.
As an improvement to the assignee's commercial system based upon the invention of the U.S. Pat. No. 4,467,431, an additional, "excess overlap" sensor was included in the sensor housing in order to detect the travel of the shears blades beyond the desired point of maximum overlap to a predetermined point at which an alarm is triggered warning the operator that a reset of the drive electronics or other corrective action is required. Other improvements, not directly relevant to the present invention, are the inclusion of a further sensor which detects the return of the shears to a given, small interval from the base-line or equilibrium position, and the incorporation of a "cushion delay" circuit which acts in cooperation with such further ("park") sensor to enable the operator to adjust the cushioning of the shears return stroke. This drastically reduced the possibility of excessive impact in the system illustrated in the U.S. Pat. No. 4,467,431.
Accordingly, it is a principal object of the invention to provide an improved system for controlling the operation of pneumatically driven straight-line shears. In particular, it is desired to improve the accuracy with which the maximum travel of the shears can be controlled.
Another object is to reduce the normal variation of shears travel, thereby providing more reliable gob drop characteristics and other performance advantages.
SUMMARY OF THE INVENTION
In furthering the above and additional objects, the invention provides a control system for controlling the cyclical operation of fluidically driven shears for severing gobs from a stream of molten glass, including means for energizing the shears fluidic drive to cause the shears to move towards each other; means for reversing the energizing means; zero crossover sensor means for producing first and second signals at the respective times in each cycle when the shears pass their zero crossover positions; means for defining a deadband period relative to the time of said first signal; and means for adjusting the time of reversing the energizing means if said second signal occurs outside of the deadband period. The adjusting means delays the time of reversing the energizing means if said second signal occurs before the deadband period, and advances the time of reversing the energizing means if said second signal occurs after the deadband period. No adjustment is made if said second signal occurs during said deadband period.
Advantageously, means are provided for altering the deadband period. This adjustment can be both in the beginning of said deadband period, and the duration of such period.
Such control system may further include means for defining an "excessive bandwidth" period which is wider than the deadband period, and an alarm means for signalling to the operator if the second signal occurs outside of such excessive bandwidth period. The control system may further include means for defining a maximum time allowed between said first and second signals, and for disabling the energizing means if the second signal occurs after this time is exceeded.
The preferred embodiment of the invention comprises an improved apparatus and method for controlling the shears of a glassware forming machine sharing many of the same features as disclosed in commonly assigned U.S. Pat. No. 4,467,431. Such improved control system includes means for energizing the shears to cause them to move towards each other, a return sensor for producing a return signal output when the shears are at a first predetermined position in each cycle, a return delay timer responsive to such return signal output for producing a delayed output for reversing the energizing means, and a zero crossover sensor for producing first and second signals at the respective times in each cycle in which said shears pass their zero crossover positions. In addition to the above elements, all found in the system of U.S. Pat. No. 4,467,431, the control system includes means for defining a deadband period relative to the time of said first signal, and means for detecting whether or not said second signal occurs within said deadband period and for adjusting the time of said delayed output in the event said second signal occurs outside of said deadband period.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and additional aspects of the invention are illustrated in the following detailed description of the preferred embodiment, which should be taken together with the drawings in which:
FIG. 1 is a circuit schematic diagram of a "deadband" control circuit in accordance with the invention;
FIG. 2 is a graph of shear blade motion vs. time;
FIG. 3 is a plot of the width of the zero crossover pulse over a number of cycles with no servocontrol of overlap;
FIG. 4 is the pulse width of the zero crossover pulse over a number of cycles, with servocontrol;
FIG. 5 is an interpolated plot of shears overlap displacement as related to the pulse width of the zero crossover pulse;
FIG. 6 is a plot of displacement over a number of shear cycles, with various settings of the "deadband" circuit of FIG. 1; and
FIG. 7 is a prior art graph of shear blade motion vs. time, for the shears control system of U.S. Pat. No. 4,467,431 as improved subsequently to the filing of such patent.
DETAILED DESCRIPTION
Reference should now be had to FIGS. 2 and 7, which respectively represent the shears motion control characteristics of the present invention, and the characteristics of a prior art system. These figures plot the distance travelled by the shears in the vertical axis, against time on the horizontal axis. The prior art plot of FIG. 7 is quite similar to FIG. 6 of U.S. Pat. No. 4,467,431, but includes an additional Excess Overlap sensor signal which is issued in response to the shears travelling a certain distance beyond the desired overlap displacement. The significance of the various other signals shown in FIG. 7 and their functioning in regulating shears overlap displacement is disclosed in the U.S. Pat. No. 4,467,431.
FIG. 2 gives a shears motion profile characteristic in accordance with the present invention. Not directly relevant to the present invention is the more rapid "cushioning" of the shears return motion. The phenomenon underlying the present invention is the empirically proven correlation between the pulse width of the Zero Crossover Signal (t o , t 1 , or t 2 ) and the overlap displacement (d o , d 1 , or d 2 , respectively). Applicants have observed that these characteristics remain correlated within a small error over a large number of shears cycles; cf. discussion of FIG. 5, below.
Reference is made in the specification and claims hereof to "first" and "second" signals indicating the respective times in each cycle in which the shears have passed their Zero Crossover position. In the preferred embodiment, such signals comprise the leading and trailing edges of the Zero Crossover pulse, respectively. However, it is certainly possible to employ other types of signals for this purpose.
Referring now to FIG. 1, there is shown a schematic of a deadband control circuit embodying the principles of the invention. As illustrated in FIG. 2, the Zero Crossover signal is a pulse which goes low during the period of overlap of the shears. During this period, the counting/dividing system comprising elements U1, U2, U9, and U6 is released for counting. U1 and U2, respectively, divide the 100 KHz input signal by 100 (1 KHz out) and 2 (500 Hz out). (Similarly, frequency divider U3 provides a 1 KHz output signal.) U9 is a five stage Johnson counter having ten decoded outputs (pins 3, 2, 4, 7, 10, 1, 5, 6, 9, and 11, respectively). In an operative embodiment of the invention, element U9 comprised a CD4017B type counter/divider of Radio Corporation of America. The positive clock transitions at input CP advances the U9 counters one count every 2 milliseconds. At the end of five steps (10 milliseconds), output 10 goes high providing data for flip flops U5 and U7. On the next selected high to low transition (determined by the operator's setting of a jumper 55 from bus 58) at the CP input to FF U7, shift register U4 is loaded. Illustratively, U4 consisted of a CD4015B type 4-stage shift register of Radio Corporation of America. The loading of U4, which has four parallel-output registers, permits these registers to advance one stage each millisecond. On the pulse selected by the setting of jumper 65, FF U7 is reset; thus FF U7 is set for 1, 2, 3, or 4 milliseconds.
Reference should now be had to U.S. Pat. No. 4,467,431, and in particular to FIG. 7 and the specification starting at column 6, line 17. In the system of the present invention, the "Return Delay Timer" circuit 14 of U.S. Pat. No. 4,467,431 FIG. 7 is modified by eliminating the Overlap Sensor-Optical coupler 252 input to FF 254, and replacing this with the Overlap signal from the circuit of FIG. 1 of the present application. Additionally, the "count inhibit" input of up/down counter 225, which is connected to the common negative level in the prior art circuit of the U.S. Pat. No. 4,467,431, is disconnected therefrom and connected to the Inhibit output of FF U8. The Overlap output of FF U7 provides a 1, 2, 3, or 4 msec pulse during which the adjustment direction of the "return delay" circuit is set for "down". If the Zero Crossover pulse ends (reverts to high) during the time FF U7 is set, FF U8 will be set and its Inhibit output will go high which inhibits the "return delay" counter from any change. Advantageously, in the event a correction of the return delay period is enabled, the circuit (U.S. Pat. No. 4,467,431 FIG. 7) counts up or down by a time change of 0.04 msec per cycle. This is a finer resolution than the 0.1 msec per cycle of the prior art. (cf. column 7, lines 27-30 of U.S. Pat. No. 4,467,431). FF U8 is reset at the end of the "start delay" period, "ON" point 204 in FIG. 7, for the next cycle.
Although the deadband circuit of FIG. 1 is designed to operate in conjunction with the "Return Delay Timer" circuit of FIG. 7 from U.S. Pat. No. 4,467,431, it should be noted that the "deadband" principle of the present invention has broader applicability. That is, it may be used with other schemes for determining the deactuation time of a shears drive assembly, and not just the Return Sensor-Return Delay arrangement of U.S. Pat. No. 4,467,431.
In the configuration of FIG. 1, FF U5 is connected via line 59 to counter/divider U9 to be set on a count of 13 (26 milliseconds) and reset on the next count of 2 (4 msec.). The output of FF U5 provides an "Excess Overlap" signal at a predetermined duration of the Zero Overlap signal. Thus, if the Zero Crossover pulse width exceeds the predetermined value, i.e. its trailing edge occurs outside of a bandwidth period defined by this value, an "excess overlap" signal is generated. Naturally, this bandwidth period is wider than the deadband period. The circuit may incorporate a plurality of circuits of this type, e.g. to indicate whether the second signal occurs at an unduly early point (before the deadband period), or to have more than one "excess overlap" level--perhaps one level which issues an alarm and another, higher, level which shuts the shears down. Each of these would utilize appropriate jumper settings, as discussed below with reference to FIG. 5.
The technique of the invention makes use of the observed tendency of pneumatically driven straight line shears of the type shown in commonly assigned U.S. Pat. No. 4,174,647, to exhibit a well defined range of Zero Crossover values. FIG. 3 shows that over a large number of shears cycles, during which the Zero Crossover pulse width drifted upwards due to friction, wear, and other factors, this signal followed a natural bandwidth on the order of 1 millisecond. During these measurements, the shears were not subject to servocontrol of overlap displacement. This natural bandwidth provides a good basis for setting the "deadband" period in the circuit of FIG. 1, by indicating how "tight" a control over Zero Crossover is compatible with the natural properties of the system.
FIG. 4 illustrates Zero Crossover pulse width measurements taken over a number of shears cycles using the circuit of FIG. 1 for servocontrol of Zero pulse width, with the jumper 65 set for a 1 msec. deadband interval, and a 0.04 msec. time change. The Zero Crossover pulse width varied as shown between upper and lower boundaries of 21.2 msec. and 20.3 msec.--a bandwidth of 0.9 msec. With reference to FIG. 2, this corresponds to a variation of the Return Delay within interval 119, and a variation of the Off point (start of actuation pulse 117 for the Retract solenoid) between extremes 122 and 123.
FIG. 5 plots pulse width against overlap displacement, and shows a curve fit to various groups 161-166 of readings taken over a large number of cycles with the "deadband" circuit of FIG. 1, each group corresponding to a different setting of the jumper 55. The regular pattern of these readings permits the fitting of a curve 170 which provides a well defined correlation between Zero pulse width and overlap displacement. Thus, it is possible to design the pulse width characteristics of a deadband control circuit such as that of FIG. 1 in accordance with known overlap displacement characteristics. This can be used to set "excess overlap" Zero Crossover pulse widths at which an alarm can be provided, or more extreme values at which the system should be shut down (the Excess Overlap signal from FF U5 of FIG. 1 is designed to shut the system down), taking into account prior knowledge of suitable overlap displacements for these actions. On receiving an "excess overlap" alarm, the operator can reset the "deadband" circuit to test whether the problem arises from the drive electronics vs. a valve malfunction or the like.
FIG. 6 shows overlap displacement variation over a number of shears cycles, at successive settings of the jumper 55 (FIG. 1). This clearly illustrates the flexibility of the operator's control over overlap displacement using the circuit of FIG. 1.
Applicants have observed that tracking Zero Crossover pulse widths during ongoing operation of the shears provides an excellent basis for diagnosing system performance. One may correlate the "signatures" of the Zero Crossover values with various types of fluidic drive malfunctions (faulty valves, piston seal leakage, etc.) and other problems, and use this to alert the operator to problems in advance of any serious impairment.
While reference has been made to specific embodiments, it will be apparent to those skilled in the art that various modifications and alterations may be made thereto without departing from the spirit of the present invention. Therefore, it is intended that the scope of this invention be ascertained by reference to the following claims. | A control system for controlling the operation of the shears of a glassware forming machine. The control system incorporates sensors which produce signals representative of predetermined shear positions in each shear cycle, and in particular, makes use of the correlation between the duration of a Zero Crossover Signal and the point of maximum overlap of the shears. The system adjusts the time of deactuation of a fluidic drive assembly, and therefore, the overlap displacement, if the termination of the Zero Crossover pulse falls outside a defined "deadband". The Zero Crossover signal may also be monitored to provide alarm signals or shut the system down. | 2 |
FIELD OF THE INVENTION
[0001] The invention generally relates to compositions, articles and methods for scavenging by-products of an oxygen scavenging reaction.
BACKGROUND OF THE INVENTION
[0002] It is well known that limiting the exposure of an oxygen-sensitive product to oxygen maintains and enhances the quality and “shelf-life” of the product. In the food packaging industry, several means for regulating oxygen exposure have already been developed.
[0003] These means include modified atmosphere packaging (MAP) for modifying the interior environment of a package; gas flushing; vacuum packaging; vacuum packaging combined with the use of oxygen barrier packaging materials; etc. Oxygen barrier films and laminates reduce or retard oxygen permeation from the outside environment into the package interior.
[0004] Another method currently being used is through “active packaging.” The inclusion of oxygen scavengers within the cavity or interior of the package is one form of active packaging. Typically, such oxygen scavengers are in the form of sachets which contain a composition which scavenges the oxygen through chemical reactions. One type of sachet contains iron compositions which oxidize. Another type of sachet contains unsaturated fatty acid salts on a particulate adsorbent. Yet another type of sachet contains metal/polyamide complex.
[0005] One disadvantage of sachets is the need for additional packaging operations to add the sachet to each package. A further disadvantage arising from the use of some sachets is that certain atmospheric conditions (e.g., high humidity, low CO 2 level) in the package are required in order for scavenging to occur at an adequate rate.
[0006] Another means for limiting the exposure to oxygen involves incorporating an oxygen scavenger into the packaging structure itself. This achieves a more uniform scavenging effect throughout the package. This may be specially important where there is restricted air circulation inside the package. In addition, such incorporation can provide a means of intercepting and scavenging oxygen as it passes through the walls of the package (herein referred to as an “active oxygen barrier”), thereby maintaining the lowest possible oxygen level throughout the package.
[0007] One attempt to prepare an oxygen-scavenging wall involves the incorporation of inorganic powders and/or salts. However, incorporation of these powders and/or salts causes degradation of the wall's transparency and mechanical properties such as tear strength. In addition, these compounds can lead to processing difficulties, especially in the fabrication of thin films, or thin layers within a film structure. Even further, the scavenging rates for walls containing these compounds are unsuitable for some commercial oxygen-scavenging applications, e.g. Such as those in which sachets are employed.
[0008] Other efforts have been directed to incorporating a metal catalyst-polyamide oxygen scavenging system into the package wall. However, this system does not exhibit oxygen scavenging at a commercially feasible rate.
[0009] Oxygen scavengers suitable for commercial use in films of the present invention are disclosed in U.S. Pat. No. 5,350,622, and a method of initiating oxygen scavenging generally is disclosed in U.S. Pat. No 5,211,875. Both applications are incorporated herein by reference in their entirety. According to U.S. Pat. No. 5,350,622, oxygen scavengers are made of an ethylenically unsaturated hydrocarbon and transition metal catalyst. The preferred ethylenically unsaturated hydro-carbon may be either substituted or unsubstituted. As defined herein, an unsubstituted ethylenically unsaturated hydrocarbon is any compound which possesses at least one aliphatic carbon-carbon double bond and comprises 100% by weight carbon and hydrogen. A substituted ethylenically unsaturated hydrocarbon is defined herein as an ethylenically unsaturated hydrocarbon which possesses at least one aliphatic carbon-carbon double bond and comprises about 50%-99% by weight carbon and hydrogen. Preferable substituted or unsubstituted ethylenically unsaturated hydrocarbons are those having two or more ethylenically unsaturated groups per molecule. More preferably, it is a polymeric compound having three or more ethylenically unsaturated groups and a molecular weight equal to or greater than 1,000 weight average molecular weight.
[0010] Preferred examples of unsubstituted ethylenically unsaturated hydrocarbons include, but are not limited to, diene polymers such as polyisoprene, (e.g., trans-polyisoprene) and copolymers thereof, cis and trans 1,4-polybutadiene, 1,2-polybutadienes, (which are defined as those polybutadienes possessing greater than or equal to 50% 1,2 microstructure), and copolymers thereof, such as styrene-butadiene copolymer. Such hydrocarbons also include polymeric compounds such as polypentenamer, polyoctenamer, and other polymers prepared by cyclic olefin metathesis; diene oligomers such as squalene; and polymers or copolymers with unsaturation derived from dicyclopentadiene, norbornadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 4-vinylcyclohexene, or other monomers containing more than one carbon-carbon double bond (conjugated or non-conjugated).
[0011] Preferred substituted ethylenically unsaturated hydrocarbons include, but are not limited to, those with oxygen-containing moieties, such as esters, carboxylic acids, aldehydes, ethers, ketones, alcohols, peroxides, and/or hydroperoxides. Specific examples of such hydro-carbons include, but are not limited to, condensation polymers such as polyesters derived from monomers containing carbon-carbon double bonds, and unsaturated fatty acids such as oleic, ricinoleic, dehydrated ricinoleic, and linoleic acids and derivatives thereof, e.g. esters. Such hydrocarbons also include polymers or copolymers derived from (meth)allyl (meth)acrylates. Suitable oxygen scavenging polymers can be made by trans-esterification. Such polymers are disclosed in WO 95/02616, incorporated herein by reference as if set forth in full. The composition used may also comprise a mixture of two or more of the substituted or unsubstituted ethylenically unsaturated hydrocarbons described above. While a weight average molecular weight of 1,000 or more is preferred, an ethylenically unsaturated hydrocarbon having a lower molecular weight is usable, provided it is blended with a film-forming polymer or blend of polymers.
[0012] As will also be evident, ethylenically unsaturated hydrocarbons which are appropriate for forming solid transparent layers at room temperature are preferred for scavenging oxygen in the packaging articles described above. For most applications where transparency is necessary, a layer which allows at least 50% transmission of visible light is preferred.
[0013] When making transparent oxygen-scavenging layers according to this invention, 1,2-polybutadiene is especially preferred for use at room temperature. For instance, 1,2-polybutadiene can exhibit transparency, mechanical properties and processing characteristics similar to those of polyethylene. In addition, this polymer is found to retain its transparency and mechanical integrity even after most or all of its oxygen capacity has been consumed, and even when little or no diluent resin is present. Even further, 1,2-polybutadiene exhibits a relatively high oxygen capacity and, once it has begun to scavenge, it exhibits a relatively high scavenging rate as well.
[0014] When oxygen scavenging at low temperatures is desired, 1,4-polybutadiene, and copolymers of styrene with butadiene, and styrene with isoprene are especially preferred. Such compositions are disclosed in U.S. Pat. No. 5,310,497 issued to Speer et al. on May 10, 1994 and incorporated herein by reference as if set forth in full. In many cases it may be desirable to blend the aforementioned polymers with a polymer or copolymer of ethylene.
[0015] Other oxygen scavengers which can be used in connection with this invention are disclosed in U.S. Pat. Nos. 5,075,362 (Hofeldt et al.), 5,106,886 (Hofeldt et al.), 5,204,389 (Hofeldt et al.), and 5,227,411 (Hofeldt et al.), all incorporated by reference herein in their entirety. These oxygen scavengers include ascorbates or isoascorbates or mixtures thereof with each other or with a sulfite, often sodium sulfite.
[0016] Still other oxygen scavengers which can be used in connection with this invention are disclosed in PCT patent publications WO 91/17044 (Zapata Industries) and WO94/09084 (Aquanautics Corporation), both incorporated by reference herein in their entirety. These oxygen scavengers include an ascorbate with a transition metal catalyst, the catalyst being a simple metal or salt or a compound, complex or chelate of the transition metal; or a transition metal complex or chelate of a polycarboxylic or salicylic acid or polyamine, optionally with a reducing agent such as ascorbate, where the transition metal complex or chelate acts primarily as an oxygen scavenging composition.
[0017] Yet other oxygen scavengers which can be used in connection with this invention are disclosed in PCT patent publication WO 94/12590 (Commonwealth Scientific and Industrial Research Organisation), incorporated by reference herein in its entirety. These oxygen scavengers include at least one reducible organic compound which is reduced under predetermined conditions, the reduced form of the compound being oxidizable by molecular oxygen, wherein the reduction and/or subsequent oxidation of the organic compound occurs independent of the presence of a transition metal catalyst. The reducible organic compound is preferably a quinone, a photoreducible dye, or a carbonyl compound which has absorbence in the UV spectrum.
[0018] Sulfites, alkali metal salts of sulphites, and tannins, are also contemplated as oxygen scavenging compounds.
[0019] As indicated above, the ethylenically unsaturated hydrocarbon is combined with a transition metal catalyst. While not being bound by any particular theory, the inventors observe that suitable metal catalysts are those which can readily interconvert between at least two oxidation states. See Sheldon, R. A.; Kochi, J. K.; “ Metal-Catalyzed Oxidations of Organic Compounds” Academic Press, New York 1981.
[0020] Preferably, the catalyst is in the form of a transition metal salt, with the metal selected from the first, second or third transition series of the Periodic Table. Suitable metals include, but are not limited to, manganese II or III, iron II or III, cobalt II or III, nickel II or III, copper I or II, rhodium II, III or IV, and ruthenium II or III. The oxidation state of the metal when introduced is not necessarily that of the active form. The metal is preferably iron, nickel or copper, more preferably manganese and most preferably cobalt. Suitable counterions for the metal include, but are not limited to, chloride, acetate, stearate, palmitate, caprylate, linoleate, tallate, 2-ethylhexanoate, neodecanoate, oleate or naphthenate. Particularly preferable salts include cobalt (II) 2-ethylhexanoate and cdbalt (II) neodecanoate. The metal salt may also be an ionomer, in which case a polymeric counterion is employed. Such ionomers are well known in the art.
[0021] The ethylenically unsaturated hydrocarbon and transition metal catalyst can be further combined with one or more polymeric diluents, such as thermoplastic polymers which are typically used to form film layers in plastic packaging articles. In the manufacture of certain packaging articles well known thermosets can also be used as the polymeric diluent.
[0022] Polymers which can be used as the diluent include, but are not limited to, polyethylene terephthalate (PET), polyethylene, low or very low density polyethylene, ultra-low density polyethylene, linear low, density polyethylene, polypropylene, polyvinyl chloride, polystyrene, and ethylene copolymers such as ethylene-vinyl acetate, ethylene-alkyl (meth) acrylate s, ethylene-(meth)acrylic acid and ethylene-(meth) acrylic acid ionomers. Blends of different diluents may also be used. However, as indicated above, the selection of the polymeric diluent largely depends on the article to be manufactured and the end use. Such selection factors are well known in the art.
[0023] Further additives can also be included in the composition to impart properties desired for the particular article being manufactured. Such additives include, but are not necessarily limited to, fillers, pigments, dyestuffs, antioxidants, stabilizers, processing aids, plasticizers, fire retardants, anti-fog agents, etc.
[0024] The mixing of the components listed above is preferably accomplished by melt-blending at a temperature in the range of 50° C. to 300° C. However alternatives such as the use of a solvent followed by evaporation may also be employed. The blending may immediately precede the formation of the finished article or preform or precede the formation of a feedstock or masterbatch for later use in the production of finished packaging articles.
[0025] Although these technologies offers great potential in packaging applications, it has been found that oxygen scavenging structures can sometimes generate reaction byproducts which can affect the taste and smell of the packaged material (i.e. organoleptic properties), or raise food regulatory issues. These by-products can include acids, aldehydes and ketones.
[0026] The inventors have found that this problem can be minimized by the use of zeolites (such as organophilic zeolites) which absorb odor-causing reaction byproducts. The zeolites can be incorporated into one or more layers of a multilayer film or container which includes an oxygen scavenging layer. However, one of ordinary skill in the art will readily recognize that the present invention is applicable to any oxygen scavenging system that produces by-products such as Acids, aldehydes, and ketones.
[0027] Definitions
[0028] “Film” (F) herein means a film, laminate, sheet, web, coating, or the like which can be used to package a product.
[0029] “Zeolite” herein refers to molecular sieves, including alumino-phosphates and aluminosilicates with a framework structure enclosing cavities occupied by large ions and/or water molecules, both of which have considerable freedom of movement permitting ion exchange and reversible dehydration. The framework may also contain other cations such as Mn, Ti, Co, and Fe. An example of such materials are the titanosilicate and titanoaluminosilicate molecular sieves. Unlike amor-phous materials, these crystalline structures contain voids of discrete size. A typical naturally occurring zeolite is the mineral faujasite with formula
[0030] Na 13 Ca 11 Mg 9 K 2 Al 55 Si 137 O 384 .235H 2 O.
[0031] Ammonium and alkylammonium cations may be incorporated in synthetic zeolites, e.g. NH 4 , CH 3 NH 3 , (CH 3 ) 2 NH 2 , (CH 3 ) 3 NH, and (CH 3 ) 4 N. Some zeolites have frameworks of linked truncated octahedra (Beta-cages) characteristic of the structure of sodalite. Numerous synthetic zeolites are available.
[0032] “Oxygen scavenger” (OS) and the like herein means a composition, article or the like which consumes, depletes or reacts with oxygen from a given environment.
[0033] “Actinic radiation” and the like herein means any form of radiation, such as ultraviolet radiation or electron beam irradiation, disclosed in U.S. Pat. No. 5.211,875 (Speer et al.).
[0034] “Polymer” and the like herein means a homopolymer, but also copolymers thereof, including bispolymers, terpolymers, etc.
[0035] “Ethylene alpha-olefin copolymer” and the like herein means such heterogeneous materials as linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE) and very low and ultra low density polyethylene (VLDPE and ULDPE); and homogeneous polymers such as metallocene catalyzed polymers such as EXACT (TM) materials supplied by Exxon, and TAFMER (TM), materials supplied by Mitsui Petrochemical Corporation. These materials generally include copolymers of ethylene with one or more comonomers selected from C 4 to C 10 alpha-olefins such as butene-1 (i.e., 1-butene), hexene-1, octene-1, etc. in which the molecules of the copolymers comprise long chains with relatively few side chain branches or cross-linked structures. This molecular structure is to be contrasted with conventional low or medium density polyethylenes which are more highly branched than their respective counterparts. Other ethylene/alpha-olefin copolymers, such as the long chain branched homogeneous ethylene/alpha-olefin copolymers available from the Dow Chemical Company, known as AFFINITY. (TM) resins, are also included as another type of ethylene alpha-olefin copolymer useful in the present invention.
[0036] As used herein, the term “polyamide” refers to polymers having amide linkages along the molecular chain, and preferably to synthetic polyamides such as nylons. Furthermore, such term encompasses both polymers comprising repeating units derived from monomers, such as caprolactam, which polymerize to form a polyamide, as well as copolymers of two or more amide monomers, including nylon terpolymers, also referred to generally as “copolyamides” herein.
[0037] “LLDPE” herein means linear low density polyethylene, which is an ethylene alpha olefin copolymer.
[0038] “EVOH” herein means ethylene vinyl alcohol copolymer.
[0039] “EVA” herein means ethylene vinyl acetate copolymer.
SUMMARY OF THE INVENTION
[0040] In one aspect of the invention, an article of manufacture comprises an oxygen scavenger and a zeolite.
[0041] In a second aspect of the invention, a package comprisesan article and a container into which the oxygen sensitive article is disposed, the container including a component comprising an oxygen scavenger and a zeolite.
[0042] In a third aspect of the invention, a method of making an article of manufacture having reduced migration of by-products of an oxygen scavenging reaction comprises providing an article comprising an oxygen scavenger and a zeolite and exposing the article to actinic radiation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The invention may be further understood with reference to the drawings wherein FIGS. 1 through 5 are schematic cross-sections of various embodiments of a film of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] The invention can be used to make various articles of manufacture, compounds, compositions of matter, coatings, etc. Two preferred forms are sealing compounds, and flexible films, both useful in packaging of food and non-food products.
[0045] It is known to use sealing compounds in the manufacture of gaskets for the rigid container market. Large, wide diameter gaskets are typically made using a liquid plastisol. This plastisol is a highly viscous, liquid suspension of polymer particles in a plasticizer. In the manufacture of metal or plastic caps, lids, and the like, this liquid plastisol is applied to the annulus of a container such as a jat, and the container with the applied plastisol is “fluxed” in an oven to solidify the plastisol into a gasket. The result is a gasket formed around the annulus of the container.
[0046] Smaller gaskets are typically made for use in beer crowns in bottles. A polymer melt is applied by cold molding to the entire inner surface of the crown. Both PVC and other polymers are used in this application.
[0047] Discs for plastic caps are typically made by taking a ribbon of gasket material and making discs, and inserting the discs into the plastic cap.
[0048] In all of these applications, the use of an oxygen scavenger and zeolite beneficially provides removal of oxygen from the interior environment of the container, while controlling undesirable by-products of the oxygen scavenging reaction.
[0049] Thus, a gasket includes a polymeric composition, an oxygen scavenger, and a zeolite. The gasket adheres a metal or plastic lid or closure to a rigid or semi-rigid container, thus sealing the lid or closure to the container.
[0050] Referring to FIG. 1, a multilayer film 10 is shown, having layer 12 and layer 14 .
[0051] [0051]FIG. 2 shows a multilayer film with layers 12 , 14 , and 16 . Layers 12 , 14 , and 16 are preferably polymeric.
[0052] Layer 12 comprises a zeolite. Preferred materials are the molecular sieves of the type disclosed in U.S. Pat. No. 4,795,482 (Gioffre et al.), incorporated herein by reference in its entirety. Also useful in the present invention are zeolites supplied by the Davison division of W.R.Grace &, Co.-Conn. Preferred particle sizes for zeolites used in the present invention are between 0.1 and 10 micrometers, and more preferably between 0.5 and 3 micrometers.
[0053] Layer 14 comprises an oxygen scavenger, preferably a polymeric oxygen scavenger, more preferably one of the materials described above.
[0054] Layer 16 comprises an oxygen barrier material, such as ethylene vinyl alcohol copolymer (EVOH), Saran (vinylidene chloride copolymer), polyester, polyamide, metal, silica coating, etc.
[0055] [0055]FIG. 3 shows a laminated film in which a three layer film is adhered to a second film. Layers 32 , 34 , and 36 correspond functionally and compositionally to 12 , 14 , and 16 respectively of FIG. 2, and layer 38 is an intermediate layer which can comprise any polymeric material such as polyolefin, more preferably ethylenic polymers such as ethylene/alpha-olefin and ethylene/unsaturated ester copolymers, more preferably ethylene/vinyl acetate copolymer. Layer 31 represents a conventional adhesive such as polyurethane adhesive. Comparative 2 in Table 6 exemplifies the laminated film of FIG. 3.
[0056] [0056]FIG. 4 shows a laminated film in which a four layer film is adhered to a second film. Layers 42 , 44 , 46 and 48 correspond functionally and compositionally to layers 32 , 34 , 36 and 38 respectively of FIG. 3. Layer 49 is an innermost heat sealable layer which can comprise any polymeric material such as polyolefin, more preferably ethylenic polymers such as ethylene/alpha-olefin and ethyene/unsaturated ester copolymers, such as ethylene vinyl acetate copolymer. Layer 46 provides oxygen barrier to the film structure, and adheres to layer 48 by means of conventional adhesive 41 . This adhesive corresponds to layer 31 of FIG. 3, and is shown simply as a thickened line. Examples 2 and 3 of Table 6 exemplify the laminated film of FIG. 4.
[0057] [0057]FIG. 5 shows a nine layer film. Example 1 and Comparative 1 in Table 2 exemplify the film of FIG. 5.
[0058] Layer 57 is an abuse-resistant layer useful as an outermost layer of a film when used in a packaging application.
[0059] Layers 54 and 56 correspond functionally and compositionally to layers 14 and 16 respectively of FIGS. 2 and 3, as well as to layers 44 and 46 respectively of FIG. 4.
[0060] Layers 52 , 53 , 58 and 59 comprise an adhesive. The adhesive is preferably polymeric, more preferably acid or acid anhydride-grafted polyolefins. In addition, these layers can comprise a zeolite.
[0061] Layer 55 comprises a heat resistant material. This can be any suitable polymeric material, preferably an amide polymer such as nylon 6 , or a polyester such as polyethylene terephthalate.
[0062] Layer 51 comprises a heat sealable material. This can be any suitable polymeric material, preferably an olefinic polymer such as an ethylenic polymer, more preferably an ethylene alpha olefin copolymer. In addition, layer 51 can further comprise a zeolite.
[0063] The invention may be further understood by reference to the examples shown below. Table 1 identifies the materials used in the examples. The remaining tables describe the films made with these materials, and organoleptic or migration data resulting from testing some of these films.
TABLE 1 MATERIAL TRADENAME SOURCE DESCRIPTION PE 1 Dowlex ™ 3010 Dow LLDPE, an ethylene/ 1- octene copolymer with a density of 0.921 gm/cc PE 2 Dowlex ™ 2244 A Dow LLDPE, an ethylene/ 1- octene copolymer with a density of 0.916 gm/cc PE 3 Poly-eth 1017 Chevron low density polyethylene PE 4 AC-9A Allied polyethylene powder AB 1 10,075 ACP Sy- Tecknor 89.8% low density loid ™ antiblock Color polyethylene (Exxon LD concentrate 203.48) + 10% synthetic amorphous silica (Syloid ™ 74X6500 from Davison Chemical) + 0.2% calcium stearate PP 1 Escorene Exxon polypropylene PP292.E1 Z 1 10414-12 zeolite Colortech masterbatch of 80% concentrate LLDPE and 20% UOP Abscents ® 3000 zeolite Z 2 10417-12 zeolite Colortech masterbatch of 80% concentrate LLDPE and 20% UOP Abscents ® 2000 zeolite Z 3 USY zeolite Grace zeolite Davison Z 4 ZSM-5 zeolite Grace zeolite Davison Z 5 ZN-1 Grace zeolite Davison Z 6 X5297H Engelhard titanium silicate zeolite AD 1 Plexar ™ 107 Quantum anhydride-grafted EVA AD 2 Adcote 530 and Morton mixture of silane, isocy- Coreactant 9L23 Inter- anate, glycol, and alkyl national acetate PA 1 Ultramid ™ KR BASF nylon 6 4407-F (polycaprolactam) OB 1 LC-H101BD Evalca ethylene/vinyl alcohol copolymer with 38 mole % ethylene OS 1 RB-830 JSR 1,2-polybutadiene OS 2 VISTALON ™ Exxon ethylene-propylene-diene 3708 terpolymer OS 3 VECT0R ™ 8508- Dexco styrene/butadiene copoly- D mer with 30% by weight of the styrene comonomer, and 70% by weight of the butadiene comonomer EV 1 MU-763 Quantum ethylene/vinyl acetate copolymer EV 2 PE 1375 Rexene ethylene/vinyl acetate copolymer with 3.6 wt. % vinyl acetate comonomer EV 3 LD-318.92 Exxon ethylene/vinyl acetate co- polymer with 9 wt. % vinyl acetate comonomer EB 1 Lotryl 30BA02 Atochem ethylene/butyl acrylate copolymer with 30 wt. % butyl acrylate copolymer PI 1 benzophenone Sartomer photoinitiator PI 2 benzoylbiphenyl — photoinitiator TC 1 TENCEM ™ 170 OMG cobalt neodecanoate, a transition metal catalyst TC 2 cobalt oleate Shepherd a transition metal catalyst F 1 50m-44 Mylar ™ Dupont Saran-coated polyethylene terephthalate film
[0064] Certain materials were blended together for some of the film structures, and these blends are identified as follows:
PEB 1 =90% PE 1 +10% AB 1 .
PEB 2 =90% PE 1 +10% PEB 3 .
PEB 3 =80% PE 3 +20% PE 4 .
PPB 1 =60% PP 1 +40% EB 1 .
PPB 2 =40% PP 1 +60% EB 1 .
OSB 1 =76.5% OS 1 +13.5% OS 2 +9.2% EV 1 +0.5% Pl 1 +0.3% TC 1 .
OSB 2 =50% OS 3 +40% PE 3 +8.54% EV 1 +0.90% TC 1 +0.50% PI 1 +0.05% calcium oxide+0.01% antioxidant (Irganox 1076).
OSB 3 =60% OS 3 +38.83% EV 3 +1.06% TC 2 +0.10% Pl 2 +0.01% antioxidant (Irganox 1076).
OSB 4 =40% OS 3 +58.83% EV 3 +1.06% TC 2 +0.10% Pl 2 +0.01% antioxidant (Irganox 1076).
ZB 1 =87% PE 1 +10% AB 1 +3% Z 1 .
ZB 2 =90% PE 2 +10% Z 1 .
ZB 3 =90% PE 2 +10% Z 2 .
ZB 4 =90% PE 2 +6% PE 3 +2% PE 4 +1% Z 3 +1% Z 4
ZB 5 =80% PE 2 +20% Z 2 .
ZB 6 =80% PE 3 +20% Z 2 .
[0065] In Table 2, a nine-layer film structure in accordance with the invention, and a comparative film, are disclosed. These were each made by coextrusion of the layers.
TABLE 2 EXAMPLE STRUCTURE 1 PEB 1 /AD 4 /OB 1 /AD 4 /OSB 1 /AD 4 /PA 1 /AD 4 /ZB 2 COMP. 1 PEB 1 /AD 4 /OB 1 /AD 4 /OSB 1 /AD 4 /PA 1 /AD 4 /PEB 1
[0066] The target (and approximate actual) gauge (in mils) of each layer of the nine-layer film is shown below. Layer 9 would preferably form the food or product contact layer in a typical packaging application.
layer layer layer layer layer layer layer layer layer 1 2 3 4 5 6 7 8 9 1.35 0.20 0.50 0.20 0.50 0.20 1.00 0.20 1.35
[0067] The films of Example 1 and Comparative 1 were subjected to food law migration tests to evaluate whether zeolites could reduce the concentration of extractables. The films were triggered by ultraviolet light according to the procedure disclosed in U.S. Pat. No. 5,211,875. The films were converted into 280 cm 2 pouches and the pouches were filled with a food simulant. The filled pouches were then retorted at 100° C. for 30 minutes and stored at 50° C. for 10 days. The food simulant was decanted from the pouches and analyzed. Table 3 shows a list of potential extractables. Table 4 shows the concentration of the same extractables, where the films were extracted with 8% ethanol solution as the food simulant. Table 5 shows the concentration of the same extractables, where the films were extracted with water as the food simulant. In both Tables 4 and 5, the concentration of each extractable is in units of nanograms/milliliter. Zeolites can reduce the concentration of certain extractables which could cause regulatory issues.
TABLE 3 ABBREVIATION DESCRIPTION E 1 benzophenone E 2 triphenyl phosphine oxide E 3 Permanax ™ WSP (antioxidant)* E 4 dilauryl thiodipropionate E 5 methyl formate E 6 ethyl formate E 7 methanol E 8 formaldehyde E 9 acetaldehyde E 10 acetone E 11 acrolein (2-propenal) E 12 propanal
[0068] [0068] TABLE 4 EX. E 1 E 2 E 3 E 4 E 5 E 6 E 7 E 8 E 9 E 10 1 21 21 <10 <5 <600 <300 3,310 1,400 6,700 100 COMP. 1 <20 40 <10 <5 <600 <300 2,960 1,600 7,800 80
[0069] [0069] TABLE 5 EX. E 1 E 2 E 3 E 4 E 5 E 6 E 7 E 8 E 9 E 10 1 22 13 <10 <5 <600 <300 <600 320 780 50 COMP. 1 21 16 <10 <5 <600 <300 <600 310 730 50
[0070] In Table 6, two five-layer laminate structures in accordance with the invention, and one comparative four-layer laminate structure, are disclosed. The two five-layer structures were each made by laminating a coextruded four-layer film, using a conventional adhesive, to a second film (=layer 5 ). The comparative structure was made by laminating a coextruded three-layer film, using a conventional adhesive, to a second film (=layer 4 ).
TABLE 6 EXAMPLE STRUCTURE 2 PE 2 /ZB 2 /OSB 2 /EV 2 //AD 2 //F 1 3 PE 2 /ZB 3 /OSB 2 /EV 2 //AD 2 //F 1 COMP. 2 PE 2 /OSB 2 /EV 2 //AD 2 //F 1
[0071] The target (and approximate actual) gauge (in mils) of each layer of the laminate structures of the invention was:
layer 1 layer 2 layer 3 layer 4 adhesive layer 5 0.20 0.20 0.50 1.00 (minimal) 0.50
[0072] The target (and approximate actual) gauge (in mils) of each layer of the comparative laminate structures was:
layer 1 layer 2 layer 3 adhesive layer 4 0.40 0.51 1.04 (minimal) 0.50
[0073] The film of Examples 2 and 3 were subjected to food law migration tests to evaluate whether zeolites could remove oxidation by-products. Their efficacy was compared with Comparative 2. The list of extractables can be found in Table 3. The test results from the extraction of the films with Miglyol 812 (available from Huls America), a fatty food simulant, are summarized in Table 7. Zeolites can reduce the concentration of certain extractables which could cause regulatory issues.
TABLE 7 Migrant (ppb) COMP. 2 EX. 2 EX. 3 E 9 <Q.L. <Q.L. <Q.L. E 10 <Q.L. <Q.L. <Q.L. E 11 <D.L. <D.L. <D.L. E 1 980 1000 +/− 5 875 +/− 23 E 8 <D.L. <D.L. <D.L. E 12 <D.L. <D.L. <D.L.
[0074] D.L.=detection limit=50 parts per billion (food equivalent).
[0075] Q.L.=quantifiable limit=150 parts per billion (food equivalent).
[0076] In Table 8, three five-layer laminate structures in accordance with the invention, and one comparative five-layer laminate structure, are disclosed. The five-layer structures were each made by laminating a coextruded four-layer film, using a conventional adhesive, to a second film (=layer 5 ).
TABLE 8 EXAMPLE STRUCTURE 4 PE 2 /ZB 2 /OSB 3 /EV 2 //AD 2 //F 1 5 PE 2 /ZB 3 /OSB 3 /EV 2 //AD 2 //F 1 6 PE 2 /ZB 4 /OSB 3 /EV 2 //AD 2 //F 1 COMP. 3 PE 2 /PEB 2 /OSB 3 /EV 2 //AD 2 //F 1
[0077] The target (and approximate actual) gauge (in mils) of each layer of the laminate structures of the invention and the comparative was:
layer 1 layer 2 layer 3 layer 4 adhesive layer 5 0.15 0.15 0.50 1.00 (minimal) 0.50
[0078] Sliced turkey breast was stored in packages made from the films of Examples 4, 5, 6 and Comparative 3. A sensory panel tasted the turkey slices to evaluate whether or not zeolites can reduce the off-flavor caused by byproducts of the oxygen-scavenging reaction.
[0079] The films were triggered by ultraviolet light according to the procedure disclosed in U.S. Pat. No. 5,211,875. The films were converted into packages on a Multivac® R7000 packaging machine. Cryovac® T6070B film was used as the bottom web of the packages. Each package contained one slice of turkey. Each package was flushed with a gas mixture consisting of 99% N 2 and 1% O 2 . Packages were stored in the dark for 7 days at 40° F.
[0080] A sensory panel rated the taste of the turkey slices. The scale ranged from 1 to 6, with 1 indicating extreme off-flavor and 6 indicating no off-flavor. The average scores are summarized in Table 9. In some cases, zeolites can reduce the off-flavor caused by the byproducts of the oxygen-scavenging reaction.
TABLE 9 Film Average Score 4 2.3 5 3.9 6 2.5 COMP. 3 2.6
[0081] In Table 10, two five-layer laminate structures in accordance with the invention, and two comparative five-layer laminate structure, are disclosed. The five-layer structures were each made by laminating a coextruded four-layer film, using a conventional adhesive, to a second film (=layer 5 ).
TABLE 10 EXAMPLE STRUCTURE 7 ZB 5 /PPB 1 /OSB 4 /ZB 6 //AD 2 //F 1 COMP. 4 PE 2 /PPB 1 /OSB 4 /PE 2 //AD 2 //F 1 8 ZB 5 /PPB 2 /OSB 4 /ZB 6 //AD 2 //F 1 COMP. 5 PE 2 /PPB 2 /OSB 4 /PE 2 //AD 2 //F 1
[0082] The target (and approximate actual) gauge (in mils) of each layer-of the laminate structures of the invention and the comparative was:
layer 1 layer 2 layer 3 layer 4 adhesive layer 5 0.15 0.15 0.50 1.00 (minimal) 0.50
[0083] Sliced turkey breast was stored in packages made from the films of Examples 7 and 8 and Comparatives 4 and 5. A sensory panel tasted the turkey slices to evaluate whether or not zeolites can reduce the off-flavor caused by the byproducts of the oxygen-scavenging reaction.
[0084] The films were triggered by ultraviolet light according to the procedure disclosed in U.S. Pat. No. 5,211,875. The films were converted into packages on a Multivac® R7000 packaging machine. Cryovac® T6070B film was used as the bottom web of the packages. Each package contained one slice of turkey. Each package was flushed with a gas mixture consisting of 99% N 2 and 1% O 2 . Packages were stored in the dark for 7days at 40° F.
[0085] A sensory panel rated the taste of the turkey slices. The scale ranged from 1 to 6, with 1 indicating extreme off-flavor and 6 indicating no off-flavor. Table 11 summarizes the percentage of the panelists which did not taste an off-flavor (i.e. a score of 6) in the packaged turkey slices. In some cases, zeolites can significantly reduce the off-flavor caused by the byproducts of the oxygen-scavenging reaction.
TABLE 11 Percentage of Panelist which did not taste an off-flavor in the Film packaged turkey 7 39% COMP. 4 17% 8 17% COMP. 5 13%
[0086] A headspace gas chromatography (GC) method was used to determine the ability of a material to absorb aldehydes. The material (either 6 to 7 mg of powder or 25 mm disk of LLDPE film containing 4% absorber) was placed in a headspace GC vial (22 mL), and 2 μL of an aldehyde mixture containing about 0.1% each of the indicated aldehydes in methanol was injected into each vial. The vials were incubated at 80° C. for 1 hour and were injected into a GC. The data in Table 12 shows the percent change in the aldehyde concentration for each material relative to an appropriate control (vial with no absorber or LLDPE disk).
TABLE 12 Percent of Aldehydes Absorbed by Candidate Absorbers Sample Propenal Pentanal Hexanal Heptanal Octanal Percent Chance Relative to Aldehyde Control Z 5 −77 4 −18 −21 −28 Z 6 −57 −93 −99 −100 −100 Percent Change Relative to LLDPE Control Z 4 −95 n/t c −100 −85 n/t Z 3 −92 n/t −77 −100 n/t
[0087] The data in Table 12 shows that various zeolites are capable of reducing the migration of aldehydes. In addition, due to specificity of various materials it can be seen that blends of materials can be advantageous.
[0088] Films of the invention can been made by any conventional means, including coextrusion, lamination, extrusion coating, or corona bonding, and then optionally irradiated and/or oriented. They can be made heat shrinkable through orientation or tenterframing if desired, at orientation ratios of 1:2 to 1:9 in either or both of the machine and transverse directions. For shrink applications, they can be made to have a free shrink of at least 10%, more preferably at least 20%, most preferably at least 30%, in either or both directions at 90° C.
[0089] Gasket compositions of the invention can be made by any conventional process, including, but not limited to, extrusion compounding for thermoplastic compositions, and conventional mixing equipment for plastisol compositions. The gasket compositions of the invention can then be formed into gaskets on lids by any conventional process, including but not limited to, cold molding processes, inserted discs, application of liquid plastisols via pressurized nozzles followed by solidification in an oven, etc.
[0090] Various changes and modifications may be made without departing from the scope of the invention defined below. For example, a blend of different zeolites can be used in the same article (e.g. film or sealing compound). In films, although it is preferred that the zeolite be used in the film and as a packaging material such that the zeolite is disposed closer to the contents of the package, which can be food or any oxygen-sensitive product, than the oxygen scavenger, there may be applications where the zeolite is disposed “outside of” the oxygen scavenger, such that the oxygen scavenger-containing layer is disposed closer to the contents of a package made from the film, than the zeolite-containing layer. The zeolite can alternatively be disposed on both sides of the oxygen scavenger. Also, within the same film, a first zeolite can be used in a first layer, and a second zeolite, different from the first zeolite, can be used in another layer of the film.
[0091] Alternatively, the zeolite, in addition to or instead of the arrangements described above, can be disposed in the same layer or layers as the oxygen scavenging material. Thus, by way of example, any of layers 14 , 34 , 44 , and 54 of the examples and figures can include any suitable percent, by weight of the layer, of a zeolite. A preferred blend of oxygen scavenging and zeolite in such a blend layer is between 95% and 99.5% oxygen scavenger, and between 0.5% and 5% zeolite. Any suitable polymeric materials can be employed in films containing the zeolites, and are not limited to those listed herein.
[0092] The amount of zeolite used in a film of the present invention is preferably between 0.1% and 5% of the layer in which it occurs; These percentages are based on the zeolite material (e.g. zeolite) per se, with suitable adjustment to be made if the zeolite material is used as a masterbatch with another material such as polyethylene. Above 5% of the layer, optics of the film can be compromised to some extent, although the film can still be used in many applications. In end-use applications where optics are not a critical feature of the package, such as opaque films or gaskets for containers, higher amounts of zeolites can be beneficially used.
[0093] Zeolites disclosed herein can be used with or in films or coatings, or absorbed into a variety of other supports for scavenging or other uses, such as a layer or coating on another object, or as a bottle cap or bottle liner, as an adhesive or non-adhesive insert, sealant, gasket, fibrous matte or other inserts, or as a non-integral component of a rigid, semi-rigid, or flexible container. | An article of manufacure includes an oxygen scavenger and a zeolite. The article can be in the form of e.g. a film or sealing compound. A package can be made from the article for containing an oxygen-sensitive article such as food. The zeolite reduces migration of odor causing by-products of the oxygen scavenging process. A method of making an article of manufacture having reduced migration of by-products of an oxygen scavenging reaction includes providing an article including an oxygen scavenger and a zeolite; and exposing the article to actinic radiation. | 1 |
BACKGROUND OF THE INVENTION
The invention relates to pneumatic tires which have improved wet traction and handling characteristics as well as improved noise and irregular wear characteristics.
This application is somewhat related to copending applications U.S. Ser. Nos. 07/666,816; 07/666,811; D667,100; 07/666,329; 07/666,328; and 07/666,815 incorporated herein by reference, and filed on even date herewith.
Irregular wear has become a problem in tires in recent years due mainly to the expanding use of front wheel drive and the use of new suspension systems and braking systems. Design changes directed toward the irregular wear problem and wet traction problems have sometimes caused handling problems and tire noise problems.
Hydroplaning of tires on wet pavement has long been a problem in the prior art. Various tire designs, adapted to channel water away from the tire, and thereby maintain rubber contact with the road have been tried by the prior art to correct this problem. Although prior art rain tire designs have improved wet traction, it is a continuing goal in the art to further improve wet traction.
It is an object of the present invention to provide a pneumatic tire having improved wet traction while having good handling, improved noise and improved irregular wear characteristics.
Other objects of the invention will be apparent from the following description and claims.
Definitions
"Aqua Channel" refers to an extra wide circumferential groove with angled (non parallel), rounded groove walls designed specifically to channel water out of the footprint of the tire.
"Aspect Ratio" of the tire means the ratio of its section height to its section width.
"Bead" means that part of the tire comprising an annular tensile member wrapped by ply cords and shaped, with or without other reinforcement elements such as flippers, chippers, apexes, toe guards and chafers, to fit the design rim.
"Carcass" means the tire structure apart from the belt structure, tread, undertread, and sidewall rubber over the plies, but including the beads.
"Crown" refers to the circumferentially outermost portion of the carcass substantially within the width limits of the tread.
"Design rim" means a rim having a specified configuration and width.
"Directional tread" refers to a tread design which has a preferred direction of rotation in the forward direction of travel.
"Equatorial plane (EP)" means the plane perpendicular to the tire's axis of rotation and passing through the center of its tread.
"Footprint" means the contact patch or area of contact of the tire tread with a flat surface at zero speed and under design load and pressure.
"Footprint Net-to-gross" refers to the actual footprint of a deflected tire and is the ratio of the ground contacting surface area of the tread to the total tread footprint area including the groove void area.
"Groove" means an elongated void area in a tread that may extend circumferentially or laterally about the tread in a straight, curved, or zig-zag manner Grooves ordinarily remain open in the tire footprint. Circumferentially and laterally extending grooves sometimes have common portions and may be subclassified as "wide" or "narrow". Grooves may be of varying depths in a tire. If such narrow or wide grooves are of substantially reduced depth as compared to wide circumferential grooves which they interconnect, they are regarded as forming "tie bars" tending to maintain a rib-like character in the tread region involved.
"Sipes" refer to small slots molded into ribs of tire that subdivides the tread surface and improves traction characteristics. Sipes tend to close completely in a tire footprint.
"Slots" are elongated void areas formed by steel blades inserted into a cast or machined mold or tread ring. Slots ordinarily remain open in a tire footprint. In the appended drawings, slots are illustrated by single lines because they are so narrow.
"Logarithmic spiral" refers to a spiral that has a gradually expanding arc, as opposed to a substantially constant arc as in for example an Archemedic spiral (i.e. as seen in a phonograph record).
"Lugs" refer to discontinuous radial rows of tread rubber in direct contact with the road surface.
"Normal load and inflation pressure" refers to the specific design inflation pressure and load assigned by the appropriate standards organization for the design rim and service condition for a tire of specific size. Examples of standards are the Tire and Rim Association Manual and the European Tire and Rim Technical Organization.
"Open angle" refers to a groove wall angle which causes the groove to be wider at the top as compared to its width at the tread base.
"Pitch" refers to the circumferential distance from one design feature in the tread pattern to the next similar design feature.
"Pitch boundary" refers to a substantially lateral line in the circumference of the tire that defines the beginning or end of the pitch. The pitch boundary may sometimes be defined by the center of a lateral groove. A pitch boundary "shift" refers to a circumferential displacement of the line.
"Radial" and "radially" are used to mean directions radially toward or away from the axis of rotation of the tire.
"Shoulder" refers to the upper portion of sidewall just below the tread edge.
"Sidewall" means that portion of a tire between the tread and the bead.
"Tie-Bar" refers to an extra thickness of rubber at the bottom of a slot such that, in the locations where the extra rubber is present, the slot depth is less than the slot depth at all other locations. Tie-bars stabilize a lug by limiting the independent movement of two portions of a lug that are separated by slots, while traction properties that are inherent in the use of slots are provided.
"Tread" means a molded rubber component which, when bonded to a tire casing, includes that portion of the tire that comes into contact with the road when the tire is normally inflated and under normal load.
"Tread width" means the arc length of the road contacting tread surface in the axial direction, that is, in a plane parallel to the axis of rotation of the tire.
SUMMARY OF THE INVENTION
A pneumatic tire for use on paved surfaces having a net-to-gross ratio of 50% to 80% and an aspect ratio of 0.35 to 0.80 is provided. The tire tread is divided into at least two annular portions, each annular portion having a plurality of block elements separated by lateral grooves. Each block element is continuous in its own annular portion of the tire and has substantially circumferentially aligned notches in leading and trailing groove walls, each of which is defined laterally by a narrow bridge of rubber and the circumferential notches and lateral grooves define lugs. Slots containing tie bars are present in each lug from the shoulder of the tire to its midportion, and the slots and the narrow bridges of rubber permit limited independent movement of the lugs.
In the illustrated embodiment, the tire has conventional construction and comprises a pair of annular beads, carcass plies wrapped around the annular beads, the tread disposed over the carcass plies in a crown area of the tire and sidewalls disposed between the tread and beads. The tread is directional and has a net-to-gross ratio of 50% to 70% and an annular aqua channel having a width of about 10% to 20% of the total treadwidth based on the footprint of the tire.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a portion of a tire of the invention.
FIG. 2 illustrates a cross section of the tire.
FIG. 3 illustrates a lug of the tire.
FIG. 3A illustrates an alternative lug of the tire.
FIG. 4 illustrates a portion of the tread pattern of the tire showing the curved pitch.
FIG. 5 illustrates a footprint produced by the tire illustrated in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
With reference now to FIG. 1, in the illustrated embodiment tire 10 has a tread portion 11 which is divided into two parts, 11a, 11b by aqua channel 12. Curved lateral grooves 14 initiate in aqua channel 12 and take an uninterrupted arcuate path to shoulder 20. Circumferential notches 16 intersect lateral grooves 14 forming lugs 18.
Those skilled in the art will recognize that a similar tread pattern can be used on a pneumatic tire without employing an aqua channel.
In the embodiment of tire 10, lugs or lug segments 18 between pairs of lateral grooves 14 may be characterized as a single element or block since lug segments 18 are connected to each other by bridges 19. In certain locations, the tread depth of the slots is about 0.53 cm (0.21 in) and are not as deep as the grooves (about 0.79 cm (0.31 in) or greater). The rubber between the bottom of the slot, in these locations, and the tread base are known as tie bars 38. Thus bridge 19 connects the leading portion 37 of one lug with the trailing portion 39 of an adjacent lug, and together with tie bars 38 provide a continuous connection between lugs from the shoulder to the center of the tire.
In the prior art, it has been shown that long lateral lugs are particularly prone to irregular wear, presumably because of the distortion of the lug and the resulting squirm when part of a lug is in a footprint and part of the lug is outside the footprint. In the lug configuration of tire 10, although bridges 19 tie the lugs 18 together into one continuous block, providing lateral stability to the tire, the small amount of rubber employed in bridges 19 and slots 17 allow the lugs limited independent movement as parts of the lug enter or leave the footprint, reducing the amount of squirm and consequent irregular wear. The lateral stability attributed to the bridges provides good handling and cornering properties.
Bridges 19 also substantially eliminate groove wander since they prevent the circumferential notches 16 from locking into longitudinal road grooves.
Bridges 19 also maintain the width of notches 16 in the footprint, assuring the widest possible flow path for the longitudinal grooves. Tie bars 38 and bridges 19 cause each set of lugs between a pair of lateral grooves to act together, stiffening the tread and reducing relative strain of individual lugs.
For basically the same reason that a rubber band hums when it is stretched and released, it is believed that at least some tire noise is caused by the acceleration of the lugs when the lug is released from a footprint and the lug is restored from distortion. Since lugs 18 are tied together and support one another, it is believed that the amount of distortion of the lugs is minimized and that the acceleration of the lug coming out of the footprint is damped, in both cases reducing the noise of the tire.
Each annular portion of the tread has an S-shaped lateral groove 14.
It should be noted that the lugs 18a adjacent to aqua channel 12 are contoured into the aqua channel, forming a part of the aqua channel such that the aqua channel has a curved U shape (having a rounded bottom and curved sides) substantially as shown in FIG. 2, and that the lateral grooves 14 initiate well into the aqua channel.
When driving on wet roads, the presence of the lateral grooves in the aqua channel substantially facilitates the flow of water from the aqua channel into the lateral grooves and out of the footprint of the tire through the shoulder. The curvature of the lateral grooves is such that the center or initial portion 14a of a lateral groove is in the leading edge of the footprint initiating the flow of water before the rest of the lateral groove enters the footprint. As the main portion of the lateral groove 14 enters the footprint, water in lateral groove 14 is expelled through the shoulder area with great force. Accordingly, the tread of the tire of the invention is directional since, if the tire is mounted such that the center portion 14a of the lateral groove enters the footprint last, water would be channeled toward, instead of away from the aqua-channel 12.
In the illustrated embodiments the tread has a designed total net-to-gross ratio of 45% to 70%, preferably 45% to 60%. In the part of the tread that touches the road (i.e. excluding the aqua channel), the tread has a net-to-gross ratio of about 60% to 90%, preferably 68% to 80% and in the illustrated embodiments about 73%. In the illustrated embodiment the overall design net-to-gross ratio is about 55%. It is believed that the high traction properties of the tire, even when the overall net to gross is very low, is partially attributable to the fact that there is a large amount of rubber in contact with the road in the portions of the tire that contact the road.
The design width of aqua channel 12 may comprise about 15-30% of the total tread width based on the tire design. In the illustrated embodiment, the design width of the aqua channel is about 25% of the overall tread width.
In a tire footprint under design load and pressure, the width of the aqua channel is 10%-22%, preferably about 15%, and the overall footprint net to gross is about 50% to 70%, preferably about 55 to 65%. In the illustrated embodiment the footprint net to gross is about 60%. In the contact patch, the part of the tire that touches the road (the footprint excluding the aqua channel), the net-to-gross is about 60%-80% preferably 65% to 75%. In the illustrated embodiment the contact patch net-to-gross is about 70%.
The depth of the aqua channel may comprise 78% to 100%, preferably 82% to 92% of the total tread depth (about 0.91 cm (0.36 in)). By total tread depth it is meant the distance from the tread base to the land area of a lug. In the illustrated embodiment the aqua channel depth is about 83% of the total tread depth or about 0.13 cm (0.05 in) less than the total depth. This depth has been chosen since it insures that the aqua channel will be present throughout the tread life of the tire since the tread wear indicators have a thickness of 0.16 cm (0.06 in).
The tire of the invention may be made to utilize a β pitch sequence, an RPAH sequence or any other pitching that is found to be acceptable for a given road surface or purpose.
Pitching as it relates to tires, is well characterized by the prior art as illustrated by U.S. Pat. No. 4,474,223 to Landers and references cited therein.
In the illustrated embodiments each nominal rib of the tire has 61-64 lugs that are divided into random pitch arrangements which contain small, medium, and large pitches. The ratio of pitch sizes may depend on the size of the tire. The ratio of the length of a small pitch to the length of a medium pitch is about 1.1 to 1.23, and the ratio of the length of a small pitch to the length of a large pitch is about 1.2 to 1.53. In the illustrated embodiment a small pitch represents a length of about 22.6 mm, a medium pitch is about 29.1 mm and a large pitch is about 40.1 mm. Because of the curvature of lateral grooves 14, the pitch boundary is curved.
In the embodiment of tire 10, tread portions 11a and 11b are skewed. By skewed it is meant there is a pitch boundary shift between tread portion 11a and tread portion 11b. Because of the pitch boundary shift, the lugs in the two portions of the tire enter into the footprint at different times reducing the amplitudes of the various sound frequencies generated by the tire during its rotation. It is believed that skewing shifts the phase angles of the sound waves generated by the two portions of the tire reducing tire noise by destructive interference and reduction in the amplitudes of the various frequencies at given instants in time. The pitch boundary shift may be approximately a 1/2 small pitch or a small pitch shift, a 1/2 medium pitch or a medium pitch shift, a 1/2 large pitch or a large pitch shift.
In the illustrated embodiment a 1/2 medium pitch shift is preferred.
The S-shape of the lateral groove extends the lateral groove deep into the shoulder area 20 and causes lateral groove 14 to curve into shoulder 20 at an angle. The curvature of the groove at the shoulder reduces the contact impact of the lugs at the shoulder area as the lug enters the footprint, because of a transitional entering of the lug into the footprint, thereby further reducing the noise of the tire.
With reference now to FIG. 2 the carcass of the tire may comprise at least one high turn up ply 27 and at least one low turn up ply 29 to improve the stiffness of tire sidewall 22.
With reference now to FIG. 3, in a preferred embodiment lug 18 may be shaped to have a leading edge groove wall 24 having an open angle of 3° to 8°, preferably about 5°, and a trailing edge groove wall 26 having an open angle of 0° to 2°, preferably about 1° Accordingly, the lugs have a trapezoidal shape having a base corresponding to the tread base 32 and a top corresponding to the land area 34 of the lug. The large open angle on the leading edge is believed to improve irregular wear properties because the angle of impact of the lug into the footprint is reduced. The open angle also has a buttressing effect on the lug, stabilizing the leading edge increasing its stiffness. Increased stiffness and a lower angle of impact reduces the amount of energy absorbed by the lug as it enters the footprint, limiting the distortion of the lug, and reducing squirm. Reduced squirm reduces irregular wear.
Also, the wider groove area at the top of the groove may enhance the flow of water out of the footprint.
The smaller angled trailing edge is believed to help maintain braking traction. The smaller angle provides a sharper element edge which keeps water from flowing under the element.
In the illustrated embodiment, because of manufacturing considerations, the trailing groove wall has an angle of 0°.
In addition, to help noise properties, and to enhance irregular wear properties leading edge 28 and trailing edge 30 may be rounded or radiused. In the illustrated embodiment, a radius of 0.15 cm (0.06 in) to 0.25 cm (0.10 in) preferably 0.20 cm (0.08 in) is used. The rounding of the edges is also believed to reduce the effects of squirming by allowing the lug to roll or rotate into the footprint.
It has been discovered that rounding the edges of the lugs also improves the grind appearance of the tire.
FIG. 3A illustrates an alternative embodiment of lug 18A which has a sharp trailing edge 30a. A sharper trailing edge is believed to be advantageous in those applications where enhanced braking traction is desired.
With reference again to FIG. 2, a cross section of the tire illustrates that the depth of aqua channel 12 may be less than 100% of the tread depth. In general it is believed that the aqua channel functions as desired when its depth is 78% to 100% of the total tread depth.
The contour of the tread, as best illustrated in FIG. 2 is an approximation to a portion of a logarithmic spiral from the equatorial plane of the tire to its shoulder. The ratio of the radius at the shoulder to the radius at the centerline is 0.28 to 0.48, preferably about 0.38. It is believed that this contour of the tread causes a more even distribution of weight in the footprint of the tire which theoretically improves traction and wear properties.
With reference now to FIG. 4, it can be seen that the curved lateral groove 14 causes a natural shift between each lug 18 along a lateral groove. That is, the lugs are not lined up laterally. Since lugs 18 are slightly shifted relative to one another, the lugs enter the footprint during rotation of the tire at different times, and since it is believed that the entry and exit of a lug from a footprint is the primary cause of tire noise, it is believed that noise is dispersed.
It can also be seen that the curvature of the lateral grooves corresponds to a curvature in the shape of the leading and trailing edges of lugs 18. Accordingly, when a lug 18 enters a footprint as the tire rotates, a relatively small edge or point 40 enters the footprint first, leading the way for the larger land area of the center of the lug. It is believed that the shape of the lug further reduces noise and irregular wear because the lug is eased or pried into the footprint by the small leading edge. The curved leading edges 28 of the lugs reduce or spread out the contact impact of the lug by its transitional loading.
It is believed that the noise of the tire can be further reduced by using a tread compound that undergoes a small amount of distortion or is slow to react or rebound either because of its stiffness or because of its relatively high hysteresis, which also reduces acceleration of a lug as it comes out of the footprint. Preferably, such a tread compound will retain good traction properties.
A preferred tread compound used in the tire is an SIBR rubber of the type as described in copending U.S. patent application Ser. No. 07/363,811, filed Jun. 9, 1989, now abandoned, and Ser. No. 07/213,019 filed Jun. 29, 1988 now U.S. Pat. No. 5,047,483, issued Sep. 10, 1991, incorporated herein by reference.
With reference now to FIG. 5, a footprint of the tire illustrated in FIG. 1 shows an overall oval shape which is typical of most well made passenger tires. The footprint comprises two base to base trapezoidally shaped contact patches. There is no collapse in the leading and trailing parts of the footprint as is typical of many prior art tires having a wide center groove. Those skilled in the art will recognize that trapezoidal shaped footprint patches that have less obtuse angles and approach the shape of a rectangle may also be desirable, and the invention is not limited by the embodiment shown.
Since the carcass and belt of the tire are conventional and are the same as those used in Eagle® GT+4 Tires and comprise 2 polyester carcass plies and 2 steel belts it is believed that the stability of the footprint, despite the wide aqua-channel, is due in part to lateral stability provided by the curved grooves in the tread. The shape of the tread lugs causes each lug to interact with a large number of radial carcass cords (contact force is spread over a large area). In the illustrated embodiment, the shape of the lugs causes each lug to interact with about 11/2 to 21/2 times as many radial reinforcement cords as and non curved lug of similar size. In the tread design where bridges 19 are used, bridges 19 further enhance the lateral stability of the tire.
Surprisingly, it has been found that when the tires of the invention are mounted backwards (i.e. with the tread design directionally opposite to the direction which provides optimum wet traction), superior performance in snow is achieved. It is believed that superior traction in snow is obtained for the same reasons that superior wet braking is achieved, i. e. the low trailing groove wall angle and the curved tread design give the tire superior biting properties.
The invention is further illustrated with reference to the following examples.
EXAMPLE 1
This example compares wet and dry slide properties of a tire of the invention (A) and a similar tire made without an aqua channel (B) to a commercially available rain tire (Uniroyal Tigerpaw™) as a control. The results are normalized to control equal 100.
__________________________________________________________________________ResultsWet 20 Wet 40 Wet 60 Dry 40ConstPeak Slide Peak Slide Peak Slide Peak Slide__________________________________________________________________________Control100 100 100 100 100 100 100 100A 124+ 123+ 132+ 111+ 125+ 101= 106+ 111+B 113+ 112+ 123+ 97- 119+ 78- 105+ 107+__________________________________________________________________________ Note: + means better than the control within a 95% confidence level = means equal to the control within a 95% confidence level - means worse than the control within a 95% confidence level
All tests were made on an asphalt surface. The results under the heading Wet 20 indicates the normalized length of the slide when full braking was initiated at 44 kph (28 mph) on a wet asphalt surface. The headings of the other tests are similarly descriptive.
For wet traction, the aquachannel appears to have a significant effect. The average peak and slide ratings were 11 to 12% higher with the aquachannel than without. The aquachannel appears to have little effect on dry traction.
The aquachannel used in this test was the narrower, shallower design illustrated in FIG. 1. The lateral and annular grooves had the configuration illustrated in FIG. 2.
EXAMPLE 2
This example illustrates a snow handling test. This test measures the "g"s encountered during acceleration, deceleration (on braking), and cornering. Measurements were made using instruments or were calculated from the data obtained. The control is an Invicta GS tire, #2 is a tire of the invention made using an SIBR rubber tread compound, #3 is a tire of the invention made using the same tread rubber as the control which was mounted backwards, #4 is the same tire as #3 mounted in the intended direction, and #5 is a Michelin XA4 tire. All tires were size P205/70R14.
______________________________________ Control #2 #3 #4 #5______________________________________Acceleration .17 .17 .17 .15 .15Deceleration .42 .42 .39 .40 .39Cornering .28 .28 .28 .26 .28______________________________________
A difference of 0.02 is the detectable limit of the test. Higher numbers show better results. The data indicates that, for these parameters, the tire of the invention is at least equivalent to all season tires now in use.
The same tires were evaluated subjectively in a packed snow handling test with the following results.
______________________________________SUBJECTIVE PACKED SNOW HANDLING______________________________________AMBIENT TEMP: 0-6 DATE: 1-30-91 DRIVER: NealeSUFRACE TEMP: 5-9 Control #2 #3 #4 #5______________________________________ACCEL: TRACTION 5 5 5 4.5 4.5ACCEL: YAW 5 5 4.5 5 4STABILITYACCEL: 0-50 m 7.95 7.92 8.06 8.41 8.34TIME-SECONDS 7.94STANDARD DEV.BRAKE: TRACTION 5 5 4.5 4.5 4.5LAT. TRACTION 5 5 5 4 5FRONTLAT. TRACTION 5 5 5.5 4 5.5REAR______________________________________Control Good straight line, slow front response then rear slideSet 2 Similar to ControlSet 3 Initial turn-in good, little rear slide, good balance.Set 4 Followed ruts, slow to turn-in, then rear slide, less trip.Set 5 Mich . . . Good lat grip, good overall balance, good turn in.______________________________________
In the subjective packed snow handling, the driver rated the performance of each tire subjectively. Higher numbers in the subjective ratings indicate better results.
EXAMPLE 3
In a different size (as compared to Example 2), the "g" measurements and subjective snow handling tests were repeated comparing an Arriva tire as a control (size P185/70R13), (#2) Corsa GT as a second control, (#3) the tire of the invention, and (#4) a Michelin X4A. As in example 2, "g"s were measured, and the driver provided his subjective conclusions.
______________________________________ Control #2 #3 #4______________________________________Acceleratin .17 .15 .14 .13Deceleration .42 .39 .40 .39Cornering .29 .30 .25 .27______________________________________
General Test Details
1. Wheels 5×13
2. 29 psi inflation
3. Vehicle: Corolla
The acceleration, deceleration and cornering data, as measured by the instruments, seems to indicate that, except that Arriva was measurably better than the Michelin XA4, the four tires had comparable properties.
The subjective rating given by the driver is tabulated below, along with the driver's comments.
______________________________________SUBJECTIVE PACKED SNOW HANDLING - T74______________________________________AMBIENT TEMP: 18-20 DATE: 1-27-91 Driver: NealeSURFACE TEMP 16-18 Control #2 #3 #4______________________________________ACCEL: Traction 5 4.5 4 4ACCEL: YAW 5 4 4.5 4STABILITYACCEL: 0-50 m 7.78 8.47 8.78 8.83TIME-SECONDS 7.78BRAKE: TRACTION 5 5 5 5LAT. TRACTION: 5 4.5 4 4.5FRONTLAT. TRACTION 5 4.5 4 4.5REAR______________________________________Control Good balance, slt o.s.Set #2 Push, then rear slide, followed rutsSet #3 Less lat grip, straight line down slightly but didn't follow ruts as badly as Set #2Set #4 Like Control but less grip, poor on following ruts______________________________________
In the subjective ratings, the higher numbers indicate the best results.
The Arriva had a good balance between straight line and lateral grip. The Corsa GT, while generating good lateral readings on the G-Analyst, understeered for the first third of the turn, then proceeded to oversteer around the rest of the turn. The tire of the invention just lacked lateral grip and usually finished the turn in a four wheel slide. The Michelin also had a good balance of traction, just at a lower limit than the Arriva.
EXAMPLE 4
Tires of the invention, along with a set of Invicta GS controls and Michelin XA4 tires, were tested for wet handling.
In the test, an Invicta GS was used as a control, a tire of the invention made without bridges between lugs was set #2, a tire of the invention made using bridges laterally between lugs was set #3, and a Michelin XA4 was set #4.
______________________________________WET HANDLING - FRONT WHEEL & 4 WHEEL DRIVEDRIVER: STOLL CON- TROL #2 #3 #4______________________________________AVG LAP TIME 57.93 56.64 56.37 58.62S.D. .19 .08 .03 .14Circle Lat Gs .669 .690 .700 .642S.D. .003 .004 .003 .001STRAIGHT LINE 5 5.5 5.5 4.5HYDROPLANINGLATERAL 5 5.5 5.5 4.5HYDROPLANINGSTEERING 5 5.5 6 4.5RESPONSEOVERSTEER 5 5 5.5 4.5OFF THROTTLE 5 5 5.5 4.5OVERSTEERTRACTION 5 5 5.5 4TRANSITIONLATERAL GRIP 5 6 5.5 4.5BRAKING TRACTION 5 7 6.5 5.5ACCELERATION 5 6 5.5 4.5TRACTION______________________________________ General Test Details 1. Wheels 5.5X14JJ stamped steel. 2. Inflation: 35 psi, F&R. 3. Load: Driver. 4. Vehicle Characteristics: Stock, aligned to OE specs.
Comments
Set 1. (Control) Lots of off-throttle oversteer. Car gets real squirrely in transients. Poor F/R balance in braking--lots of rear bias. Also, lots of understeer while powering out of corners.
Set 2. Braking grip is phenomenal compared to last set...quantum-leap improvement. Tires have more stopping power than car has brakes. Also, very good grip in cornering+acceleration. Tires feel like they have much better road contact.
Set 3. Most precise steering of all sets. Very good braking. Excellent controllability in transients, minimal O/S, good acc. grip in powering out of corners, good cornering grip.
Set 4. Tires are just slippery all over. Not predictable or smooth. Car pushes a lot under power, but rear gets real loose in transients off-throttle. Not great braking....only marginally better than controls.
Conclusions
Sets 2 and 3 were the best overall. Set 2 had braking, cornering, and acceleration grip that was far superior to the controls; it was also better than any of the sets as well. Set 3 had wet grip that was nearly equal to that of set 2, and was actually superior to set 2 for oversteer parameters. Set 3 also had a steering feel that was more precise and responsive than any other set. Further, set 3 was the fastest set tested, on both the 200' circle as well as the handling course itself. It was a very easy set to drive fast in the wet.
While specific embodiments of the invention have been illustrated and described, it will be recognized by those skilled in the art that the invention may be variously modified and practiced without departing from the spirit of the invention. The invention is limited only by the following claims. | A directional pneumatic tire having improved wet traction is provided. The tread is divided into two annular portions, each annular portion comprising a plurality of block elements separated by lateral grooves. The block elements extend continuously from a shoulder area of the tire to a mid portion of the tread. The block elements have substantially circumferentially aligned notches in leading and trailing groove walls, wherein each notch is defined laterally by a narrow bridge of rubber. The tread has curved lateral grooves to direct water from the footprint to the shoulder area of the tire to help prevent hydroplaning. The pitch boundaries between annular portions of block elements may be skewed. The curved lateral grooves and the skewing reduce noise properties of the tire. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a fluid coupling for transmitting torque from a driving member to a driven member via a fluid medium to cause the driven member to rotate. More specifically, the invention relates to a fluid coupling for transmitting rotation force from an internal combustion engine to a cooling fan.
2. Description of the Background Art
In water cooling type engines, air passing through a radiator causes heat to be radiated from cooling water. Therefore, the higher the flow rate of air passing through the radiator the better the heat radiating effect. When the vehicle is running at moderate or relatively high speeds, a sufficient amount of cooling air is forced against the front surface of the radiator. However, when the vehicular speed is low, or when the engine operates in the idling condition, the amount of cooling air is insufficient. In order that sufficient cooling air is introduced to the radiator in these cases, a cooling fan which rotates in accordance with rotation of the engine is arranged behind the radiator.
When rotation speed of the cooling fan becomes high, air resistance also becomes high, so that noise becomes great as well as the force required for rotating the fan. On the other hand, when the vehicular speed becomes high, the cooling fan does not need to draw so large an amount of air into the radiator since a large volume of air is forced against the front surface of the radiator due to air resistance to vehicle motion. For that reason, various systems have been proposed, which prevent the rotation speed of a cooling fan from increasing when the rotation speed reaches a certain value, or which cause a cooling fan to rotate only when it is required. Such systems include a fluid coupling, a fan clutch, a fan coupling and so forth.
Generally, a fluid coupling comprises a disc for receiving rotation force from an engine, and a wheel to which a cooling fan is attached. The wheel is designed to rotate in accordance with rotation of the disc via viscous resistance of silicone oil which passes through a labyrinth groove formed between circumferential surface portions of the disc and wheel. When rotation speed of the disc becomes greater than a predetermined value, the viscous resistance becomes insufficient relative to rotation speed of the disc, so that the rotation speed of the wheel does not become greater than a predetermined value.
The fan coupling has a fluid coupling which is combined with a bimetal thermostat, a sliding valve and so forth. The sliding valve is open and closed in accordance with expansion and contraction of the bimetal which expands and contracts in accordance with temperature, to adjust amount of working fluid introduced into a working chamber from a fluid storage chamber. The working fluid introduced into the working chamber is further introduced into a labyrinth groove, so that viscous resistance is produced between the disc and the wheel. In this way, the fan coupling causes the fluid coupling to operate in response to temperature of engine coolant.
In conventional fan couplings, there is a disadvantage in that, when the engine speed is rapidly increased from the engine idling condition, rotation speed of the cooling fan is rapidly increased which produces fan noise and causes power loss in the engine.
In order to overcome the aforementioned problems, Japanese Utility-Model First (unexamined) Publication (Jikkai Sho.) No. 60-58930 and (Jikkai Hei.) No. 1-131033 disclose improved fan couplings.
However, these disclosed systems have a relatively complicated valve mechanism which uses a spring or the like. Therefore, the construction thereof is not only complicated, but also many parts and high manufacturing accuracy are required. As a result, manufacturing becomes complicated, and manufacturing costs increase.
SUMMARY OF THE INVENTION
It is therefore a principal object of the present invention to provide a fluid coupling which can reduce rotation speed of a driven unit relative to that of a driving unit when the engine speed is rapidly increased.
It is another object of the present invention to provide a fluid coupling as above-mentioned which is simple in construction.
In order to accomplish the aforementioned and other objects, a fluid coupling includes a valve means for reducing working fluid passing through a viscous resistance generation portion, by which a driven unit rotates in response to rotation of a driving unit, to reduce rotation speed of the driven unit relative to that of the driving unit when the engine speed is rapidly increased.
According to one aspect of the present invention, a fluid coupling for transmitting rotation force from a driving unit to a driven unit, comprises:
a drive shaft connected to a driving unit to rotate by means of the driving unit;
a housing rotatably supported on the drive shaft and supporting thereon a driven unit, the housing defining therein an internal space;
dividing means for dividing the internal space into first and second fluid chambers;
a rotary member connected to the drive shaft to rotate together therewith and received within the second fluid chamber, the rotary member being cooperative with the housing to form a viscous resistance generating portion in the second fluid chamber, the viscous resistance generating portion receiving working fluid in the second fluid chamber for generating viscous resistance, by which the housing rotates in response to rotation of the rotary member; and
valve means for allowing the working fluid in the first fluid chamber to be introduced into the second fluid chamber, to adjust amount of the working fluid passing through the viscous resistance generating portion for varying a ratio of rotation speed of the housing to that of the rotary member, the valve means including a through opening formed in one surface of the dividing means and a valve member pivotably supported on the surface, the pivotal direction of the valve member being essentially perpendicular to the plane of the surface of the dividing means, the valve member opening the through opening when no load is applied thereto and closing the through opening when force applied thereto by rotation of the housing becomes greater than a predetermined value.
According to another aspect of the present invention, a fluid coupling for transmitting rotation force from a driving unit to a driven unit, comprises:
a drive shaft connected to a driving unit to rotate by means of the driving unit;
a housing rotatably supported on the drive shaft and supporting thereon a driven unit, the housing defining therein an internal space;
dividing means for dividing the internal space into first and second fluid chambers, the dividing means including a major disc portion which extends essentially perpendicular to the rotation axis of the housing, and an annular flange portion which projects essentially parallel to the rotation axis of the housing from the circumferential edge of the major disc portion;
a rotary member connected to the drive shaft to rotate together therewith and received within the second fluid chamber, the rotary member being cooperative with the housing to form a viscous resistance generating portion in the second fluid chamber, the viscous resistance generating portion receiving working fluid in the second fluid chamber for generating viscous resistance, by which the housing rotates in response to rotation of the rotary member; and
valve means, provided on the annular flange portion, for allowing the working fluid in the first fluid chamber to be introduced into the second fluid chamber, to adjust a volume of working fluid passing through the viscous resistance generating portion for varying a ratio of a rotation speed of the housing to that of the rotary member, the valve means being closed when force applied thereto by rotation of the housing becomes greater than a predetermined value so as to reduce the volume of working fluid passing through the viscous resistance generating portion.
According to further aspect of the present invention, a fluid coupling for transmitting rotation force from a driving unit to a driven unit, comprises:
a drive shaft connected to a driving unit to rotate by means of the driving unit;
a housing rotatably supported on the drive shaft and supporting thereon a driven unit, the housing defining therein an internal space;
dividing means for dividing the internal space into first and second fluid chambers, the dividing means including a major disc portion which extends essentially perpendicular to the rotation axis of the housing;
a rotary member connected to the drive shaft to rotate together therewith and received within the second fluid chamber, the rotary member being cooperative with the housing to form a viscous resistance generating portion in the second fluid chamber, the viscous resistance generating portion receiving working fluid in the second fluid chamber for generating viscous resistance, by which the housing rotates in response to rotation of the rotary member; and
valve means, provided on the major disc portion, for allowing the working fluid in the first fluid chamber to be introduced into the second fluid chamber, to adjust a volume of working fluid passing through the viscous resistance generating portion for varying a ratio of a rotation speed of the housing to that of the rotary member, the valve means being closed when force applied thereto by rotation of the housing becomes greater than a predetermined value so as to reduce the amount of the working fluid passing through the viscous resistance generating portion.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiments of the invention. However, the drawings are not intended to imply limitation of the invention to a specific embodiment, but are for explanation and understanding only.
In the drawings:
FIG. 1 is a sectional view of a fan coupling to which the first preferred embodiment of a fluid coupling, according to the present invention, is applied;
FIG. 2(A) is a plan view showing a valve mechanism used for the fan coupling of FIG. 1, which is viewed along the arrow 2(A) of FIG. 1;
FIG. Z(B) is a plan view showing the valve mechanism of FIG. 2(A), which is viewed along the arrow 2(B) of FIG. 2(A);
FIG. 2(C) is a perspective view showing the valve mechanism of FIG. 2(A);
FIG. 3 is a perspective view showing the second preferred embodiment of a valve mechanism which is applied to the fan coupling of FIG. 1;
FIG. 4 is a perspective view showing the third preferred embodiment of a valve mechanism which is applied to the fan coupling of FIG. 1;
FIG. 5 is a sectional view of a fan coupling to which the fourth preferred embodiment of a fluid coupling, according to the present invention, is applied; and
FIG. 6 is a plan view showing a valve mechanism used for the fan coupling of FIG. 5, which is viewed along the arrow 6 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, particularly to FIG. 1, there is shown a fan coupling to which the first preferred embodiment of a fluid coupling, according to the present invention, is applied.
As shown in FIG. 1, the fan coupling generally comprises a drive shaft 10 serving as an input means and a housing 12 serving as an output means for transmitting rotation force to a cooling fan 13 which is secured to the periphery of the housing 12. The drive shaft 10 is composed of a flange portion 10a and a shaft portion 10b. The housing 12 comprises a body member 14 and a wheel member 16. The flange portion 10a of the drive shaft 10 is secured to a V belt pulley arranged on the side of an internal combustion engine (not shown) to receive driving force from a crankshaft of the engine via the V belt pulley. The body member 14 of the housing 12 is rotatably supported on the shaft portion 10b of the drive shaft 10 via a bearing 18. The wheel member 16 of the housing 12 is secured to the body member 14 thereof such that the outer periphery of the wheel member 16 engages the circumferential inner surface of the body member 14 by way of a caulking, thereby a space is formed within the housing 12.
The wheel member 16 is integrally formed with an annular projecting portion 16a which projects inwardly from the inner surface of the wheel member 16 and which is concentric to the center thereof and spaced therefrom by a predetermined distance. This annular projecting portion 16a supports the periphery of a partition plate 20 by which the space formed within the housing 12 is divided into a storage chamber 22 and a working chamber 24.
The housing 12 receives a disc member 26 in the working chamber 24. The disc member 26 is secured to the end of the shaft portion 10b of the drive shaft 10 at the center thereof so as to receive rotation force from the engine via the drive shaft 10. The disc member 26 is integrally formed with a plurality of concentric annular projecting portions 26a which project from the circumferential surface portion of the disc member 26 toward the wheel member 16 and which are separated from each other at predetermined intervals. In addition, the wheel member 16 is integrally formed with a plurality of concentric annular projecting portions 16b which project from the circumferential surface portion of the wheel member 16 toward the disc member 26 and which are separated from each other at essentially the same intervals as that of the disc member 26. The distance between the adjoining annular projecting portions 26a of the disc member 26 is designed to be greater than the widths of the annular projecting portions 16b. The distance between the adjoining annular projecting portions 16b of the wheel member 16 are also designed to be greater than the widths of the annular projecting portions 26a. Therefore, when the annular projecting portions 26a or 16b of one of the disc member 26 and the wheel member 16 are inserted into groove formed between the other annular projecting portions 16b or 26a, there are spaces between the adjoining projecting portions 16b and 26a. The top ends of the projecting portions 26a of the disc member 26 are so arranged as to be separated from the bottoms of grooves formed between the projecting portions 16b of the wheel member 16 at a predetermined distance. On the other hand, the top ends of the projecting portions 16b of the wheel member 16 are also so arranged as to be separated from the bottoms of grooves formed between the projecting portions 26a of the disc member 26 at a predetermined distance. With this arrangement, a labyrinth groove 28 serving as a viscous resistance generating portion is formed between the circumferential surface portions of the disc member 26 and wheel member 16.
The wheel member 16 has a fluid passage 30 which establishes a fluid communication between the storage chamber 22 and the labyrinth groove 28 for returning working fluid passing through the labyrinth groove 28 to the storage chamber 22. In addition, the partition plate 20 has a through opening 32 which establishes a fluid communication between the storage chamber 22 and the working chamber 24. The through opening 32 is open and closed by means of a valve plate 34. One end of the valve plate 34 is connected to a rotary shaft 36 mounted on the wheel member 16 at essentially the center thereof. The rotary shaft 36 is also connected to the centrally located end portion of a spiral bimetal 38, the circumferentially located end portion of which is connected to a projection arranged on the outside of the wheel member 16, so that the valve plate 34 rotates in accordance with expansion and contraction of the spiral bimetal 38. As is well known, the bimetal is designed to expand and contract in accordance with temperature. Therefore, the valve plate 34 opens and closes the through opening 32 in accordance with variation of temperature.
An essentially disc-shaped bulkhead 40 is arranged between the partition plate 20 and the disc member 26. The bulkhead 40 is integrally formed with a ring-shaped flange portion 42 which extends vertically from the circumferential edge of the bulkhead 40. The circumferential edge of the flange portion 42 is secured to the outside wall of the projecting portion 16a of the wheel member 16, so that the working chamber 24 is divided into a first fluid chamber 24a formed between the partition plate 20 and the bulkhead 40, and a second fluid chamber 24b in which the labyrinth groove 28 is arranged.
As can be seen clearly from FIGS. 2(A) to 2(C), an essentially rectangular through opening 44 extending in a circumferential direction of the flange portion 42 is formed in the flange portion 42. The through opening 44 is designed to be open and closed by means of a valve mechanism 46. The valve mechanism 46 comprises an essentially rectangular valve member 48 and a stopper piece 50. The valve member 48 and the through opening 44 are simultaneously formed by way of the stamping. The stopper piece 50 extends so as to traverse the through opening 44, and the both end portions thereof are secured to the flange portion 42. The stopper piece 50 serves to prevent the valve member 48 from distorting outwards to exceed the maximum distorting position. The valve member 48 is formed so that the direction from the free end portion 48a to the fixed end portion 48b is the same as the direction of rotation of the housing 12. The valve member 48 is distorted inwardly so as to open the through opening 44 when no load is applied thereto. When the housing 12 rotates at rapid acceleration, centrifugal and inertial forces are applied to the working fluid in the first fluid chamber 24a, so that the valve member 48 is designed to deform toward its closed position by the working fluid to which the centrifugal and inertial forces are applied. In addition, the fixed end portion 48b is formed with a pair of cut-out portions establishing suitable elastic force of the valve member, which is biased to assume a position which is bent inward of the circumference of the flange 42, as shown in FIG. 2(c).
With this construction, the operation of the first preferred embodiment of a fluid coupling, according to the present invention, is described below.
Torque transmitted from the disc member 26, which rotates with the drive shaft 10 serving as the input means, to the housing 12 serving as the output means, may be expressed as a function of the flow rate of the working fluid in the working chamber 24. That is, when only slight working fluid exists in the labyrinth groove 28, the difference between rotation speeds of the input means 10 and the output means 12 is maximum, and as the amount of the working fluid increases, the difference decreases.
In a case where the engine performs usual operation after warming up, the valve plate 34 opens the though opening 32, so that the working fluid in the storage chamber 22 is introduced into the first fluid chamber 24a. When working fluid is present in the labyrinth groove 28, torque is transmitted from the disc member 26 to the housing 12 by means of viscous resistance caused by the working fluid passing though the labyrinth groove 28, so that the housing 12 rotates according to rotation of the disc member 26. When the housing 12 rotates, centrifugal force is applied to the working fluid in the first fluid chamber 24a so that thrusting force is applied to the valve member 48 of the valve mechanism 46. In this case, the thrusting force is less than the elastic force of the valve member 48 itself, so that the valve member 48 remains to open the through opening 44. Therefore, the working fluid in the first fluid chamber 24a passes through the through opening 44 as shown by the arrows of FIG. 2(C) to be rapidly introduced into the second fluid chamber 24b. The working fluid introduced into the second fluid chamber 24b is further introduced into the labyrinth groove 28, so that torque continues to be transmitted from the disc member 26 to the housing 12 by means of viscous resistance caused by the working fluid passing though the labyrinth groove 28. In this way, the cooling fan 13 may obtain usual rotation force.
On the other hand, in a case where the engine speed is rapidly accelerated from an engine idling condition, the rotation speed of the drive shaft 10 rapidly increases, which temporarily causes rapid increase in the rotation of the housing 12 due to working fluid remaining in the labyrinth groove 28. In this case, centrifugal force is not only applied to the working fluid in the first fluid chamber 24a, but inertial force is also applied to the working fluid along the inner surface 42a of the flange portion 42 of the bulkhead 40. therefore, a composite force composed of the centrifugal and inertial forces causes the valve member 48 to deform outwardly against its own elastic force until the valve member 48 comes into contact with the stopper piece 50 to close the through opening 44. In this way, fluid communication between the first and second fluid chambers 24a and 24b is blocked, so that the amount of the working fluid introduced into the labyrinth groove 28 is decreased. Therefore, it is possible to prevent the rotation speed of the cooling fan 13 from excessively increasing, that is, so-called "overshooting" of the cooling fan 13 can be prevented when the engine speed is rapidly increased from an engine idling condition.
As mentioned above, in this embodiment, "overshooting" of the cooling fan 13 can be prevented when the engine is rapidly accelerated. In addition, the construction of the valve mechanism 46 is very simple, and the number of parts thereof is less than that of conventional valve mechanisms. Specifically, since the valve member 48 may be formed by only stamping out the flange portion 42, the process for manufacturing the valve mechanism 46 becomes very easy. In addition, since the elastic force of the valve member 48 may be adjusted by changing the width and length of the fixed end portion 48b, it can be applied to different sizes of fluid couplings and so forth.
Fig. 3 shows the second preferred embodiment of a valve mechanism which can be applied to a fluid coupling, according to the present invention. In this embodiment, an essentially rectangular through opening 60 is formed in the flange portion 42, and a valve member 64 of a valve mechanism 62 is not integrated with the flange portion 42. The valve member 64 has a curved rectangular shape, and the bottom area thereof is less than open area of the through opening 60. One end portion 64b of the valve member 64 is secured to the flange portion 42 at a location neighboring the through opening 60 by way of welding, so that the direction from the free end portion 64a to the fixed end portion 64b is same as that of rotation of the housing 12. The valve member 64 is integrally formed with a thick weight portion 66.
In this embodiment, the same effect as that of the first preferred embodiment can be obtained. In addition, since the weight of the valve member 64 and the area of the valve member 64 which is interfered with the working fluid are increased, the valve member 64 can deform outwardly i.e. toward its closed position, relatively easily. Furthermore, the valve member 64 and the weight portion 66 can deform so that the free end portion 64a passes through the through opening 60.
FIG. 4 shows the third preferred embodiment of a valve mechanism which can be applied to a fluid coupling according to the present invention. In this embodiment, the construction is basically same as that of the second preferred embodiment except that the bottom areas of a valve member 74 and a weight portion 76 of a valve mechanism 72 are greater than open area of a through opening 70 formed in the flange portion 42. The valve member 74 and the weight portion 76 have a sector-shaped cross-section, so that the free end portion 74a is greater than the fixed end portion 74b. Therefore, when the valve member 74 deforms outwardly, the circumference surface portion of the valve member 74 comes into contact with the flange portion 42 around the through opening 70, so that essentially perfect blocking of the fluid communication between the first and second fluid chambers 24a and 24b can be performed. Therefore, the rotation of the cooling fan 13 can be surely stopped.
FIG. 5 shows a fan coupling to which the fourth preferred embodiment of a fluid coupling, according to the present invention, is applied. The construction of this embodiment is essentially similar to that of the first preferred embodiment except that the bulkhead 40 for dividing the working chamber 24 into the first and second fluid chamber 24a and 24b is not used, and that a partition plate 80 and a check valve 82 are substituted for the partition plate 20 and the valve mechanism 46, respectively. The partition plate 80 has an essentially cylindrical projecting portion 84 which projects toward the storage chamber 22. The projecting portion 84 serves to define a valve receiving portion 86 on the side of the working chamber 24. the top surface 84a of the projecting portion 84 has an essentially rectangular through opening 88 which is open and closed by means of the valve plate 34. The valve receiving portion 86 receives the check valve 82 therein. As can be seen clearly from FIG. 6, the check valve 82 generally comprises a cylindrical body member 90 and a disc-shaped valve plate 92. The body member 90 has a mounting piece 90a which extends from the periphery of the body member 90 toward the central point of the partition plate 80 in parallel to the partition plate 80. The valve plate 92 is supported on the mounting piece 90a of the body member 90 via an elastic leg portion 92a. When no load is applied to the valve plate 92, it is biased to be inclined in an open position. In addition, the body member 90 has a stopper piece 90b which extends inwardly from the periphery of the body member 90 at a location opposing to the mounting piece 90a in parallel to the partition plate 80. In this embodiment, the interior and exterior of the check valve 82 may serve as the first and second fluid chambers 24a and 24b, respectively.
With this construction, the operation of the fourth preferred embodiment of a fluid coupling, according to the present invention, is described below.
In a case where the engine performs usual operation after warming up, the valve plate 34 opens the through opening 88, so that the working fluid in the storage chamber 32 is introduced into the interior of the check valve 82. Torque is transmitted from the disc member 26 to the housing 12 by means of viscous resistance caused by the working fluid passing through the labyrinth groove 28, so that the housing rotates according to rotation of the disc member 26. When the housing 12 rotates, centrifugal force is applied to the working fluid in the check valve 82, so that thrusting force is applied to the valve plate 92 of the check valve 82. In this case, the thrusting force is less than the elastic force of the leg portion 92a of the valve plate 92, so that the valve plate 92 remains opened. Therefore, the working fluid in the check valve is introduced into the working chamber 24. The working fluid introduced into the working chamber 24 is further introduced into the labyrinth groove 28, so that torque continues to be transmitted from the disc member 26 to the housing 12 by means of viscous resistance caused by the working fluid passing though the labyrinth groove 28. In this way, the cooling fan 13 may obtain usual rotation force.
On the other hand, in a case where the engine speed is rapidly accelerated from the engine idling condition, rotation speed of the drive shaft 10 is rapidly increased, which causes temporary, rapid increase in the rotation speed of the housing 12 due to the working fluid remaining in the labyrinth groove 28. In this case, centrifugal force applied to the working fluid in the check valve 82 becomes greater than the elastic force of the leg portion 92a of the valve plate 92 itself. Therefore, the leg portion 92a of the valve plate 92 deforms against the reaction force itself so that the valve plate 92 is closed. In this way, the fluid communication between the storage chamber 22 and the working chamber 24 is blocked, so that the amount of working fluid introduced into the labyrinth groove 28 is decreased. Therefore, it is possible to prevent the rotation speed of the cooling fan 13 from excessively increasing, that is, "overshooting" of the cooling fan 13 can be prevented when the engine speed is rapidly increased. As a result, though the engine speed rapidly increased, it is possible to decrease noise caused by the cooling fan 13 as well as engine power loss.
While the present invention has been disclosed in terms of the preferred embodiment in order to facilitate better understanding thereof, it should be appreciated that the invention can be embodied in various ways without departing from the principle of the invention. Therefore the invention should be understood to include all possible embodiments and modification to the shown embodiments which can be embodied without departing from the principle of the invention as set forth in the appended claims. | A fluid coupling includes a valve unit for reducing working fluid introduced into a labyrinth-groove to adjust a ratio of a rotation speed of a cooling fan to that of an internal combustion engine, when the engine speed is rapidly increased. The valve unit comprises a through opening formed in one surface of a partition member which divides an internal space within a housing into two fluid chambers, and a valve plate pivotably supported on the surface of the partition member. The pivotal axis of the valve member is on a plane essentially same as that of the surface of the partition member. When no load is applied to the valve member, the valve member is positioned such that the through opening remains open, and, when force applied thereto by rotation of the housing becomes greater than a predetermined value, the valve member is moved so as to close the through opening. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention generally relates to a semiconductor device, and more particularly, to a resistance random access memory (“RRAM”) device and method for fabricating the same.
[0003] 2. Background of the Invention
[0004] RRAM is a memory device using materials with variable electrical resistance characteristics in accordance with external influences. Since the resistance will not change even after the power source has been disconnected, RRAM is a non-volatile memory device.
[0005] As other memory devices, RRAM includes a number of memory cells, each coupled to a word line and a bit line. A RRAM cell may include a bottom electrode for bit line connection, a top electrode for word line connection, and a resistive film as a variable resistor between the bottom and top electrode. The resistive film may be programmed to have high resistance or low resistance in two-state memory circuits to store one bit of data per cell, or a number of resistance-determined states in multi-state memory circuits to store multiple bits of data in a single cell. In order to have multiple resistance-determined states, the resistive film may need to provide high resistance value so that the memory may have more operation window to perform multi-bit memory operations.
BRIEF SUMMARY OF THE INVENTION
[0006] One example consistent with the invention provides a memory which comprises a number of word lines in a first direction, a number of bit lines in a second direction, each coupled to at least one of the word lines, and a number of memory elements, each coupled to one of the word lines and one of the bit lines. Each memory element comprises a top electrode for connecting to a corresponding word line, a bottom electrode for connecting to a corresponding bit line, a resistive layer on the bottom electrode, and at least two separate liners, each liner having resistive materials on both ends of the liner and each liner coupled between the top electrode and the resistive layer.
[0007] In another example, a method for fabricating a memory comprises the steps of providing a number of word lines in a first direction, providing a number of bit lines in a second direction, forming a top electrode for connecting to a corresponding word line, forming a bottom electrode for connection a corresponding bit line, forming a resistive layer on the bottom electrode, and forming at least two separate liners, each liner having resistive materials on both ends of the liner and each liner coupled between the top electrode and the resistive layer.
[0008] Another example consistent with the invention provides a method for fabricating a memory, which comprises the steps of: providing a number of word lines in a first direction, providing a number of bit lines in a second direction, forming a bottom electrode, depositing an oxide layer on the bottom electrode, forming an insulating layer on the oxide layer, patterning the insulating layer, the oxide layer and the bottom electrode, thereby leaving a portion of the bottom electrode uncovered and sides of the oxide layer exposed, forming two separate liners on the uncovered bottom electrode and along the exposed sides of the oxide layer, forming resistive materials on both ends of each liner, and forming a resistive layer on the uncovered bottom electrode.
[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended, exemplary drawings. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0011] In the drawings:
[0012] FIG. 1 is a cross-sectional view of one exemplary memory cell in accordance of the present invention;
[0013] FIG. 2 is a sectional view of a memory cell in FIG. 1 showing an exemplary manufacturing method according to the present invention;
[0014] FIG. 3 a sectional view of a memory cell in FIG. 1 showing an exemplary manufacturing method according to the present invention;
[0015] FIG. 4 is a sectional view of a memory cell in FIG. 1 showing an exemplary manufacturing method according to the present invention;
[0016] FIG. 5 is a sectional view of a memory cell in FIG. 1 showing an exemplary manufacturing method according to the present invention;
[0017] FIG. 6 is a sectional view of a memory cell in FIG. 1 showing an exemplary manufacturing method according to the present invention; and
[0018] FIG. 7 is a sectional view of a memory cell in FIG. 1 showing an exemplary manufacturing method according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to FIG. 1 , a memory cell 100 may be formed on an integrated circuit substrate 102 . The memory 100 may include a bottom electrode 104 and a top electrode 106 . A resistive layer 136 is formed on portions of the bottom electrode 104 . Between the bottom electrode 104 and top electrode 106 , there are an oxide layer 108 and a resistive structure. The resistive structure may include two L-shaped liners 120 separated by an oxide layer 114 and a layer 112 of metal or metal oxide materials. Each L-shaped liner 120 may include a first oxide liner 122 , a metal liner 124 , as well as a second oxide liner 126 . The metal liner 124 for each L-shaped liner 120 has two resistive ends 132 and 134 . Each resistive end 132 or 134 is made of either the same or different resistive materials.
[0020] Resistive materials may include chalcogenide alloy material, magnetroresistive materials, and polymer materials. Chalcogenide alloy materials may change between the crystalline and amorphous states with application of heat. Under high temperature, over 600° C. for example, the chalcogenide becomes liquid. Once cooled, it is frozen into an amorphous glass-like state and its electrical resistance is high. On the other hands, by heating the chalcogenide to a temperature between its crystallization point and its melting point, it may transform into a crystalline state with a much lower resistance. Since the crystalline and amorphous states of chalcogenide alloy materials may be distinguished in accordance with their different electrical resistivity values, this forms the basis by which data is stored. For example, the amorphous, high resistance state may be used to represent a binary 1, and the crystalline, low resistance state represents a binary 0. Chalcogenide alloy materials may be made of a mixture of germanium, antimony and tellurium called, GST. Chalcogenide alloy materials may be deposited by physical vapor deposition (PVD) sputtering or magnetron-sputtering method with reactive gases, such as Ar, N2, or He, at pressure of 1 mTorr to 100 mTorr. The deposition may be performed at room temperature. The collimator with aspect ratio of 1 to 5 may be used to improve the fill-in performance. In addition, to improve the fill-in performance, the DC bias of tens of volts to hundreds of volts may also be used. The post deposition annealing treatment with vacuum or N2 ambient, may improve the crystallize state of chalcogenide alloy materials. The temperature for annealing treatment may range from 100° C. to 400° C. with time of less than 30 minutes.
[0021] Magnetroresistive materials may have variable magnetization directions with application of a magnetic field. Due to the magnetic tunnel effect, the electrical resistance of the magnetroresistive materials changes depending on the magnetization direction. Therefore, memory cells using such materials may store data by the magnetization states and the data stored therein can be sensed by measuring the electrical resistance of the cells. Magnetroresistive materials may include colossal magneto resistive (“CMR”) thin films and oxidation thin films having Perovskite structure. CMR thin films may be formed by PVD sputtering or magnetron-sputtering method with reactive gases, such as Ar, N2, O2 or He at the pressure of 1 mTorr to 100 mTorr. The deposition temperature may range from room temperature to 600° C., depending on the post deposition treatment condition. The collimator with aspect ratio of 1 to 5 may improve the fill-in performance. In addition, the DC bias of tens of volts to hundreds of volts may also be used to improve the fill-in performance. Further, a magnetic field of tens of gauss to Tesla may be applied to improve the magnetic crystallize state. The post deposition annealing treatment with vacuum or N2 ambient or O2/N2 mixed ambient may improve the crystallize state of CMR materials. In addition, a buffer layer of YBaCuO3 with thickness of 30 nm to 200 nm may be deposited before deposition of CMR materials to improve the crystallize of CMR materials. Similarly, the oxidation thin films having Perovskite structure may be deposited by same method discussed above or formed by oxidation discussed below.
[0022] Polymer materials may have variable polarization states with application of an electric field. Since the electrical resistance of a polymer changes in accordance with the orientation of polarization of the polymer, the data stored in memory cells using polymer materials can be sensed by measuring the electrical resistance of the cells. Polymer materials may include tetracyanoquinodimethane (TCNQ) or PCBM [[6,6]-phenyl C61-butyric acid methyl ester]. Polymer materials may be formed by thermal evaporation, e-beam evaporation or MBE evaporation. A solid-state TCNQ and dopant pellets are co-evaporated in a single chamber where materials are mixed and deposited on wafers. There may be no reactive chemistries or gases. The deposition may be performed at pressure of 10-4 Torr to 10-10 Torr. The wafer temperature may range from room temperature to 200° C. The post deposition annealing treatment with vacuum or N2 ambient may improve the composition of polymer materials. The temperature for the annealing treatment may range from room temperature to 300° C. with time less than 1 hour. In addition, polymer materials may be formed by spin coating of the doped TCNQ solution with rotation of less than 100 rpm.
[0023] FIGS. 2-7 are sectional views of a non-volatile memory cell showing an exemplary method of fabricating a memory cell of FIG. 1 . Referring to FIG. 2 , conductive materials are deposited on a substrate 102 and patterned to form bottom electrodes 104 for bit line connection. In one example, the conductive materials are metals that may be subject to oxidation, such as Al, W, Ti, Ni or Cu. Inter-metal dielectric deposition is then performed to overlay bottom electrodes 104 with a layer of oxide 108 by chemical mechanical planarization. An insulating material 202 , such as silicon nitride in one example, is subsequently formed on the oxide layer 108 . The structure of FIG. 2 is patterned by vaporization to form the structure of FIG. 3 where portions of the bottom electrodes 104 are uncovered and side of the oxide layer 108 are exposed.
[0024] Referring to FIG. 4 , an oxide liner 122 is formed on the uncovered bottom electrode 104 and along the exposed sides of the oxide layer 108 by oxide liner deposition. Following that, a metal liner deposition is performed to form a metal liner 124 on the oxide liner 122 . In one example, the metal liner is made of metals that may be subject to oxidation, such as Al, W, Ti, Ni or Cu. A second oxide liner 126 is then formed on the metal liner 124 by another oxide liner deposition. Subsequently, vaporization for blanket etching is performed to form the structure of the L-shaped liner 120 .
[0025] Referring to FIG. 5 , resistive materials are formed on both ends of each metal liner 124 as well as on the uncovered portion of the bottom electrode 104 . In one example where the metal liner 124 and the bottom electrode 104 are made of metals that are subject to oxidation, the surface of metal may be oxidized to form metal oxides, at both ends 132 and 134 , and a metal oxide layer 136 on the uncovered bottom electrode 104 . Oxidation may be done by, for example, thermal oxidation having temperature ranging from 200° C. to 700° C. with pure O2 or N2/O2 mixed gas at pressure of several mTorr to 1 atmosphere. Another example of oxidation is plasma oxidation where an RF or DC source plasma with pure O2 or Ar/O2 mixed gas or Ar/N2/O2 mixed gas with pressure of 1 mTorr to 100 mTorr may be used to oxidize the surface of metal. The oxidation temperature may range from room temperature to 300° C. depending on the degree of plasma oxidation.
[0026] Referring to FIG. 6 , a layer 112 of either metal or metal oxides is deposited on the metal oxide layer 136 . A layer 114 of oxide is then formed on the layer 112 by chemical mechanical planarization. Following that, the insulating layer 122 and the resistive end 132 of the metal liner 124 may be removed by [conventional oxide CMP (planarize layer 114 , a oxide layer, then removed layer 124 )].
[0027] Referring to FIG. 7 , oxidation may be performed again to form metal oxides at the ends 132 of each metal liner 124 . By oxidation in different environment, the characteristics of the metal oxides at the ends 132 may be different from those of the metal oxides at the ends 134 . Then, a conductive material such as metal materials may be deposited on the structure of FIG. 7 for word line connection to form the structure of FIG. 1 .
[0028] With the structure of FIG. 1 , each of the resistive ends 132 and 134 forms a resistor (R 132 , R 134 ) which may provide high resistance due to its small area. The resistors R 132 and R 134 are connected in series, which are together connected in parallel with the other pair of the resistors R 132 and R 134 . In addition, the resistive layer 136 also forms a resistor R 136 in series with combination of the resistors R 132 and R 134 . In the case where the layer 112 is made of resistive materials, the layer 112 may also provide a resistor R 112 which is connected in series between resistor R 136 and combination of the resistors R 132 and R 134 . Since the resistance ends 132 and 134 have very small area, they may provide high resistance, thus resulting in more operation window to perform multi-bit memory reading and writing operations.
[0029] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. | A memory comprises a number of word lines in a first direction, a number of bit lines in a second direction, each coupled to at least one of the word lines, and a number of memory elements, each coupled to one of the word lines and one of the bit lines. Each memory element comprises a top electrode for connecting to a corresponding word line, a bottom electrode for connecting to a corresponding bit line, a resistive layer on the bottom electrode, and at least two separate liners, each liner having resistive materials on both ends of the liner and each liner coupled between the top electrode and the resistive layer. | 6 |
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