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FIELD OF INVENTION
This invention is an improved dryer-cleaner apparatus and process having a primary use and benefit in cotton gins. The combination apparatus is intended to be positioned in a cotton gin adjacent the beginning of the ginning process for the purposes of enhancing the drying of the raw cotton and more efficiently removing trash. The ultimate goals are to increase output or “turnout” and to improve the quality or grade of the final cotton product. The invention also includes a new and novel design for grid fingers for the dryer that enhances the separation of trash from the cotton and minimizes the possibility of clogging of the dryer by the trash or cotton.
BACKGROUND OF INVENTION
Cotton gins are the physical facilities that receive raw field seed cotton, its burrs and seed as well as dirt, plant stems, leaves and other trash for processing into a clean cotton fiber which is then baled for shipment to a textile plant. The existing processes and equipment contained in modern cotton gins are well depicted in the Cotton Ginners Handbook , Agricultural Handbook No. 503, of the United States Department of Agriculture, December 1994, the contents of which are incorporated herein by reference as if fully set forth herein in accord with the provisions of MPEP §608.01(p)[R-1].
The conventional ginning process is summarily illustrated in FIG. 1 which is labeled “Prior Art.” It depicts a module 12 of field seed cotton bolls that were compacted in the field and brought to the cotton gin. A module feeder (not shown) fragments and disperses the compacted cotton 12 into the individual bolls and transmits them through a large diameter pipe and a rock and green boll trap (not shown) for delivery to a dryer 16 . Prior to reaching the dryer 16 , heated air from a fan and heater is also delivered to the cotton within the pipe. The purpose of the drying is to reduce the moisture content of the raw cotton to facilitate subsequent cleaning and removal of trash. This dried cotton is then drawn into another air duct for delivery to one (or, in many cases, two) cleaners 20 which remove a portion of the burrs, stems and other trash. As depicted, the cleaner 20 is an overhead, inclined cylinder type, although other types are used in various gins. These overhead cleaners 20 remove much of the trash from the cotton before it is passed to a stick or stick and burr extractor (not shown) that removes additional burrs, stems, and trash. From the extractor, additional heated air may be added to the system to dry the cotton down to a 6 or 7% moisture level before it reaches the gin stand 22 which separates the cotton fiber from the seed. From the gin stand 22 , the cotton fiber is drawn into a pneumatic conveyor for transfer to one or more lint cleaners 24 which have the job of removing the remaining pin trash from the cotton before it is baled in the press 26 .
In this typical gin process, it is well known that the lint cleaners, in removing the trash, break some of the fiber which becomes a fuzz like substance called motes that is removed with the trash. In addition, some of the broken fiber is not separated, but is carried to the bale press. The resulting known problems includes a fiber loss as well as a reduction in the grade of the cotton due to a shorter fiber length. Consequently, if more trash could be earlier removed so that the use of the lint cleaners could be reduced or minimized, both fiber output and cotton grade could be enhanced.
Another problem in this typical process results from the fact that after the drying step, the raw cotton is immediately transferred back into a high pressure, pnuematic conduit in which it is compacted. This compaction of the cotton results in further entrapment of the cotton trash within the fiber and renders the inclined cylinder cleaners less efficient thereby increasing the need for and use of the lint cleaners. The compaction also results is carrying trash through several additional steps to the lint clearer so as to increase the wear on the machinery and increase the horsepower requirements of the process.
SUMMARY OF INVENTION
To solve or minimize the above identified problems, the present invention includes a combination dryer-cleaner that enhances the trash removal problem at the beginning of the ginning process and minimizes the need for or use of multiple saw-type lint cleaners. Specifically, the combination includes a single unit dryer-cleaner assembly that enables the cotton to be more efficiently dried and then transmitted from the dryer to the cleaner without the use of piping, conduits or conveyers which would entrap the trash and render the cleaning far more difficult. The dryer-cleaner unit also includes a novel design of T shaped grid bars that enhance the drying process and avoid clogging of the air passages so as to maximize air flow and drying.
Accordingly, the objectives of this invention are to provide a product and process that solves the above identified problems and achieves one or more of the following results:
1. avoids compacting the cotton and entrapping trash therein after it has been dried for ginning;
2. enhances moisture removal and increases the drying efficiency by breaking apart compressed wads of field cotton and exposing more surface area;
3. more efficiently removes trash from the cotton at the beginning of the ginning process;
4. reduces waste and increases the quantity of cotton fiber obtained from the raw cotton;
5. reduces and minimizes the need to use lint cleaners which damage fiber length and quality and impose higher power requirements upon the ginning process;
6. reduces the wear upon fans and conduits and reduces the power requirements for ginning cotton by early removal of trash in the ginning process; and
7. improves the quality and grade of the cotton processed by the cotton gin.
DESCRIPTION OF THE DRAWINGS
The manner in which these objectives and other desirable characteristics can be obtained from this invention is explained in the following specification and attached drawings in which:
FIG. 1 is a process diagram illustrating the prior art process of ginning of cotton;
FIG. 2 is a process diagram illustrating the preferred process of our invention which is a modification of the process of FIG. 1;
FIG. 3 is a side elevational view, partially in section, of a preferred embodiment of the combination dryer-cleaner of our invention;
FIG. 4 is a perspective view of a preferred embodiment of our grid bar improvement to the dryer element of our invention;
FIG. 4 a is an elevational view depicting the spacing of the T beams used to form the shelves within the dryer, and
FIG. 5 is a side elevational view of the far or opposite side of the preferred embodiment of FIG. 3 depicting the pulleys and drive belts for driving the dryer and cleaner.
DETAILED DESCRIPTION
The preferred embodiment of this invention is depicted in a schematic diagram of FIG. 2 which has some similarities to that of FIG. 1 labeled “Prior Art.” As in the prior art, the ginning process of this embodiment begins with the module feeder 12 or suction shed in which the raw field seed cotton is delivered to piping for transfer to the dryer-cleaner unit 18 of our invention. As in the prior art standard practice, heated air is forced into the piping just ahead of the dryer which in this case is a combination 18 of a vertical dryer 40 mounted upon a horizontal cleaner 70 . This unit is best depicted in FIG. 3 .
The dryer 40 comprises a rectangular housing 42 that receives raw cotton from pneumatic piping at its top section and discharges it at the bottom into the horizontal cleaner 70 . The cotton comes into the housing 42 with a high volume and velocity of heated air and is dried as it passes downward to the cleaner 70 at the bottom of the dryer 40 . As the cotton is blown into the cleaner 70 , it engages a first rotating, wad busting elongated cylinder 44 which breaks up and disperses any remaining compacted wads of cotton into individual bolls and thrusts the cotton bolls against an adjacent inclined grid bar shelf 48 upon which it slides down to engage another wad busting cylinder 44 having paddles 46 formed of angle iron welded thereto. During this drying process, the cotton is repeatedly thrust against the upper end of each of the grid bar shelves 48 upon which it slides downward to be engaged by the next cylinder paddle 46 and is again thrust over and upward towards the top of the next shelf 48 as depicted in FIG. 3 . The resulting circuitous route of the descending cotton assists in the removal of moisture and in dislodging embedded trash. As the cotton slides down the shelves 48 towards the cylinders 44 , air is permitted to pass through the cotton bolls and through elongated spaces 51 formed in the shelves 48 . This enhances the drying of the cotton.
FIG. 4 illustrates the details of a preferred embodiment of the shelves 48 that facilitates this drying function. Each shelf 48 is comprised of a plurality of parallel, spaced apart T beam grids 50 . They depend downwardly at an angle of about 60 degrees from the interior wall of the housing 42 of the dryer and are cut so as to terminate just above an associated paddle cylinder 44 . Preferably, these T beams 50 are economically formed of extruded aluminum and have a substantial resistance to bending deflection by virtue of the web section 50 a depending from the flange or deck top 50 b above the web.
The T bars are economically and simplistically mounted to the wall of the housing 42 by a primary bracket 52 and spacer brackets 54 . The primary bracket 52 has a flange 52 a that is affixed to the walls of the housing 42 by bolts as shown in FIG. 4 . From the wall, the bracket extends inwardly and then downwardly at a 60 degree angle. This downward support section 52 b provides an elongated support for the bottom surfaces of the flange 50 b of the T beams 50 . At the lower end of the downward support section 52 b , the bracket is bent back towards the wall of the housing 42 and then terminates in another flange 52 d . A plurality of lower spacer brackets 54 support the flange 52 d away from the wall to maintain the 60 degree angle of the support section 52 b with respect to the wall of the housing 42 .
The primary bracket 52 is provided with elongated slots 56 which receive the web 50 a of the T bars and permit the bottom surfaces of the deck or flange 50 b to engage and rest against the support section 52 b of the bracket 52 . A notch 58 on the web 50 a of the T beam engages the end of the elongated slot 56 to restrain the T bar against sliding movement down the surface. Finally, a locking plate 60 with apertures is used to lock the top end of the T beams 50 against pivotal movement about notch 58 and to maintain them in place. To facilitate attachment of the locking plate 60 , the apertures 62 may be threaded. Alternatively, locking nuts 64 may be used as shown in FIG. 4 .
As shown in FIG. 4 a , the flanges 50 b have squared edges 50 c and are spaced apart to permit the air to freely flow there through. We have found that the squared edges 50 c minimize clogging of the spaces 51 between the T beams by either cotton or trash—a fact that results in better air flow through the cotton and the spaces and results in improved drying.
By the time the cotton has reached the bottom of the dryer, its moisture has been reduced and the trash has, at this point in the process, the least tendency to cling to the cotton. Consequently, we have discovered that much of the trash can be best removed from the cotton by directly running it through a cleaner 70 and without re-compacting the cotton and trash by transferring it to a distant cleaner through piping. To that end, and as shown in FIG. 3, the cleaner 70 of our invention is positioned directly below the dryer 40 . Other than positioning and having a large access opening to the dryer 40 within the system, the cleaner 70 may be a conventional multi-cylinder horizontal line cleaner having a plurality of spike cylinders 74 that extend to the outside of the housing where they are rotatably driven by a belt and pulley system.
Preferably, the access opening between the dryer 40 and the cleaner 70 extends for the entire width of the dryer 40 and across at least one third of its length. As shown in FIG. 3, the cotton and any associated trash flows downward past the left side of the bottom paddle cylinder and into the cleaner 70 in an unobstructed manner and without compaction.
Upon reaching the cleaner 70 , the cotton is picked up by the spikes 72 on a conventional rotating spike cylinder 74 and is dragged across a plurality of spaced apart elongated cylinder grid bars 76 which are preferably arranged to define semi-circular pattern of a radius just greater than that of the spikes 72 of the cylinders 74 . The cotton is dragged across the grid bars 76 so that any trash associated with the cotton then drops through the spaced apart bars 76 and falls downward into a hopper 78 . As is customary in the art of cylinder cleaners, a plurality of cylinders 74 are provided. Preferably, the hopper 78 terminates in an auger type conveyer 80 that carries the trash to a rotary airlock 82 . This rotary air lock 82 passes the accumulated trash out of the hopper.
The side of the dryer-cleaner opposite to that of FIG. 3 is depicted in FIG. 5 . It illustrates one concept for supplying power to the dryer 40 and cleaner 70 . That power is supplied through a motor 86 which is connected by belt 90 to a pulley 88 that is constrained for rotation with the shaft (unnumbered) of the first spike cylinder 74 . A first, single pulley wheel 97 is also constrained for rotation with this shaft and, through a series of short belts 100 and a plurality of double pulley wheels 98 , drives each of the spike cylinders 74 of the cleaner 70 . The last spike cylinder 74 is driven by a single pulley 97 and a single belt because further transmission of the rotational motion is not needed.
The rotary motion of the first spike cylinder 74 of the cleaner also carries a pulley wheel on the opposite side which is tied to a first pulley wheel 92 of the lower wad busting cylinder 44 . This belt is not shown because the pertinent portion of FIG. 3 was broken away to depict the internal portion of the cylinders. As earlier mentioned, however, the lower wad busting cylinder 44 carries a single belt 94 that is serpentined through pulley wheels 92 of each of the other wad busting cylinders 44 and an idler pulley which is unnumbered. Thus, a single motor 86 supplies rotary power to the entire dryer-cleaner unit 18 .
Those skilled in the art will appreciate that this invention may take many forms. For example, instead of using the inclined shelf cleaner of FIG. 4, one could use a horizontal shelf cleaner—and still meet the invention's objective of avoiding compaction and entrapment of the trash in the cotton. In addition, the dryer and cleaner could be separated by a distance as long as an enlarged, preferably rectangular ducting were used to convey the cotton from the dryer to the cleaner without compaction or further entrapment of trash. Similarly, the dryer's T-beam shelves could be supported with different brackets and at different angles other than that disclosed in the preferred embodiment. Finally, other types of cleaners could be used below the dryer as a substitute for the horizontal cleaner disclosed. Those skilled in the art will appreciate that the width of the dryer-cleaner, the number of cylinders as well as the rotary speed of the unit are design variables that, at least in part, will be dependent upon the anticipated capacity of the entire gin equipment.
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This application discloses an improved dryer-cleaning apparatus for use in a cotton gin. It includes a dryer having rotating paddle cylinders for moving the cotton through the dryer and then discharging the cotton directly into the cleaner without compaction or entrapment of the trash within the raw cotton.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an anisotropic bonded magnet which is made by compression molding to obtain a high density and a high magnetic powder alignment and also relates to its production method.
2. Description of the Related Art
Bonded magnets are made of magnet powders embedded in organic resin or metallic resin. They have lower levels of magnetic energy compared to their fully densified counterparts such as sintered magnets.
Bonded magnets, which have excellent formability, can be formed in complex shapes with close mechanical tolerances as well as are free from cracking. Because of the above mentioned advantages, their application area is rapidly spreading.
They may be formed by extrusion, compression, and injection molding.
Injection molding has advantages in forming complex shapes and integrated components with high precision. Injection molding can form the most complicated shapes among three mentioned molding methods. However the magnet has low magnetic energy because the volume fraction of magnet powder is limited to under 60 to 65 percent to provide good flowability in the process.
Extrusion molding has merit during continuous production to provides a low cost magnet. Also extrusion molding gives better magnetic energy than injection molding due to the volume fraction of magnet powder of 70 to 75 percent.
Compression molding gives the highest magnetic energy because of maximum volume fraction of 80 to 90 percent. It can also produce magnets of complex shape.
As mentioned previously, the major shortcoming of the bonded magnet is its low maximum energy product. Recently anisotropic magnet powders with high maximum energy product have been developed to overcome the mentioned shortcomings. However compression molding which is suitable for anisotropic magnet powder has not been established facing the difficulty of contradiction of high density and magnet powder alignment.
Here, anisotropic magnet powder is an aggregation of fine magnet particles which consist of uniaxial crystals and have unidirectional magnetization. Magnet powder alignment means to align the magnetization of each particle to an applied magnetic field.
To solve the difficulty described above, the following technology concerning compression molding has been proposed.
In Japanese patent application Laid- Open (Kokai) No. 1-205403, warm molding is proposed in order to utilize a resin softening phenomenon before curing reaction is set forth. The compound consists of melt spun magnet powder and thermosetting resin.
The patent application discloses that high density is attained by use of a heating temperature of 30 to 100° C. at which the softening phenomenon occurs before curing reaction. Above 100° C. curing has begun before the magnet was sufficiently densified. Further, adhesion of resin to the mold is observed.
Using a compound which consists of Nd 14 Fe 76 Co 5 B 5 melt spun powder and epoxy resin, a bonded magnet with (BH)max of 10.3-11.2 MGOe and density of 6.7 to 7.1 g/cm 3 was attained by compression molding at 45 to 77° C.
However the magnet shows a relatively low maximum energy product of 11.2 MGOe in spite of high density of 7.1 g/cm 3 , because the melt spun rare earth magnet powder is isotropic.
Furthermore, the applied resin shows poor thermal durability due to its low melting point.
In Japanese patent application Laid- Open (Kokai) No. 2-116104, compression molding below curing temperature followed by curing is proposed. The molding temperature is set between softening point and about 50° C. higher in order to increase flowability of the resin. In this embodiment a bonded magnet with maximum energy product of 9.0 MGOe and density of 6.1 g/cm 3 was obtained.
A compound consists of ortho-cresol novolak type epoxy resin with a melting point of 40° C. and rare earth magnet powder was compression-molded at 100° C. followed by curing at 120° C. The patent application discloses that the magnet which has superior thermal durability and relatively high magnetic property with high density are obtained by forming at an elevated temperature to keep the softening state of the resin. However the magnet shows considerably low maximum energy product of 9.0 MGOe because of low density of 6.1 g/cm 3 . Furthermore the invention requires a curing process after compression molding.
Japanese patent application Laid- Open (Kokai) No. 4-11702 proposes fine resin powder which enables high magnetic property by means of reducing the amount of resin to that of magnet powder. In the invention compression molding with a magnetic field is disclosed.
The particle size of the magnet powder is from 0.1 to 500 μm, which is ordinary for this kind of use, and the particle size of the resin powder is chosen to be one tenth of the magnet powder. When they are mixed into a compound, fine resin powder covers the surface of magnet powder evenly by electro-static force. In the invention, a bonded magnet is manufactured in a single process, namely, curing is performed at the same time as compression molding. In at least one of the embodiments, a magnetic field of 15,000 Oe is applied in the compression molding.
In embodiment 1, a compound of barium ferrite magnet powder and fine polymethylmethacrylate powder with the particle size of 0.05 to 0.06 μm was compression-molded with the applied magnetic field of 15000 Oe. Curing reaction proceeds simultaneously with the molding. The obtained bonded magnet had the density of 3.40 g/m 3 and (BH)max of 1.35 MGOe.
In embodiment 3, a compound of NdFeB magnet powder (MQ powder A) and fine polymethylmethacrylate powder with the particle size of 0.05 to 0.06 μm was compression-molded with the applied magnetic field of 5000 Oe. Curing reaction proceeds simultaneously with the molding. The magnet had the density of 5.49 g/cm 3 and (BH)max of 7.3 MGOe.
In the embodiments, anisotropic powder such as hexagonal plate shaped barium ferrite or elongated NdFeB powder is used. Applied magnetic field aligns the direction of magnetization of the anisotropic powder and thus increases the maximum energy product of the bonded magnet.
In spite of the statements that the invention provides good magnetic property and high density because of reduced amount of resin, the obtained bonded magnets have low maximum energy product and low density. Therefore this invention is considered rather to combine molding and curing processes into one production step.
Japanese patent application Laid- Open (Kokai) No. 4-349603 proposes micro-capsules made of thermal polymerized resin which contains lubricant. The capsule coats the surface of magnet powder and reduces frictional resistance of the compound at the mold surface to obtain a high densified magnet. Furthermore the capsule avoids galling of mold by the compound.
In embodiment 1, a compound of (Pr, Sm)Co magnet powder are compression-molded with an applied magnetic field of 24 kOe and cured at 180° C. A bonded magnet with maximum energy product of 15.0-15.7 MGOe and density of 6.82-6.95 g/cm 3 was obtained.
However the invented process had not attained sufficient maximum energy product in spite of its high density. It may be due to low degree of magnet powder alignment although compression molding is carried out in a magnetic field of as high as 24 kOe. Another problem in this invention is that the manufacturing process of the compound becomes quite complicated. Furthermore, high density brings less amount of resin as binder and causes brittleness of the bonded magnet as well as low flowability in molding.
The major shortcoming of the bonded magnet is low maximum energy product. Therefore development of suitable compression molding has been anticipated to improve maximum energy product. The problem in compression molding of a bonded magnet was contradiction of high density and magnet powder alignment. The problem has not been solved in spite of various inventions as described previously.
SUMMARY OF THE INVENTION
To solve the problem three major aspects should be considered. First, to use anisotropic NdFeB powder with high maximum energy product; second, to increase the volume fraction of magnet powder and reduce the volume of void in the bonded magnet by compression molding; third, to achieve high degree of magnet powder alignment, preferably to the limit of theoretical value of perfect alignment.
However these three aspects contradict one another. Increased volume fraction of magnet causes deterioration of alignment. Anisotropic powder is apt to aggregate and disturb alignment.
An object of the invention is to offer a method of compression molding which achieves both high density and good magnet powder alignment and provide a bonded magnet with excellent magnetic property at an economical cost. It also gives good thermal durability to the magnet.
Compression molding utilizing NdFeB powder has been studied to solve the problem previously discribed and the following results are obtained;
(1) high degree of magnet powder alignment is obtained by applying both magnetic field and pressure at the moment when the resin is melted into liquid state, preferably at the point that viscosity is lowest. This method has been lead by the characteristics of curing process of thermosetting resin in which the resin melts into liquid for a short period of time before hardened by curing reaction.
(2) During the compression molding, curing proceeds keeping magnet powder alignment to the applied field because the pressure is applied hydrostatically due to liquid state of resin.
(3) Rotation and movement of magnet powder in the liquid resin brought by applied magnetic field accelerate the evacuation of the gas contained in compound or generated by melting reaction.
(4) Applying pulse field is effective to magnet powder alignment.
(5) Reduced pressure helps degassing after resin is melted into liquid state.
(6) Curing can be done by applying further heating and increased pressure in compression molding. Heating temperature above 120° C., preferably above 150° C., required to obtain thermal durability of the bonded magnet, because the resin with good thermal durability has relatively high temperature for softening, melting, and curing. This molding temperature also shortens the curing time and leads improvement of production rate.
Present invention is established based on the results described above. The crucial point of the invention is to carry out compression molding with applying magnetic field at the moment when thermosetting resin melts into liquid. The mold used is equipped with temperature and magnetic field control system.
The inventive production process is as follows:
To prepare compound which consists of anisotropic NdFeB magnet powder and thermosetting resin, fill it in a mold equipped with control system for temperature and magnetic field, raise the temperature above the curing point, apply magnetic field to align the magnet powder magnetization at the moment that the resin melts into liquid state, simultaneously apply pressure to form desired shape and keep the state to finish curing reaction.
Details of the present invention is described as follows;
Anisotropic magnet powder is used to produce anisotropic boned magnet with good magnetic property. The kinds of anisotropic magnet powder are R1--Co type magnet, R2--Fe--B type magnet, and R3--Fe--N type magnet. R1 and R3 contain at least one kind of rare earth element including Sm. R2 contains at least one kind of rare earth element including Nd.
R1--Co type magnet includes Sm--Co magnet, Sm--Co type magnet in which part of Sm is substituted by at least one element from Nd, Pr, Y, Ce, or Dy, and Sm--Co--Cu--Fe type magnet powder to which at least one element of Zr, Hf, or Ti are added, R2--Fe--B type magnet includes Nd--Fe--B magnet, Nd--Fe--B type magnet in which part of Nd is substituted by at least one element of Pr, Y, or Dy, and Nd--Fe--B--Co magnet and Nd--Fe--B--Co type magnet to which at least one element of Ga, Zr, Hf, Al, Cu, Mn, Si or Ti are added.
Nd--Fe--B magnet powder is prepared by the following process. Magnet powder is melt spun, then formed by hot hydrostatic isotropic press. After forming it is plastic deformed and mechanically crushed and ground into powder.
Another preparation method is HDDR (Hydrogenation, disproportionation, desorption and recombination) treatment.
Generally the powder produced by HDDR treatment has nearly spherical particles which is hard to magnetically align.
The present invention is especially effective in achieving high degree of magnetic alignment for HDDR treated powder.
R3--Fe--N type magnet includes Sm--Fe--N type magnet, Sm--Fe--Co--N type magnet and Sm--Fe--V--N type magnet.
Magnet powder can be finely ground and granulated into pellets. Fine ground magnet particles are less resistant in rotation and easily aligned by applied field.
Epoxy resin, phenol resin, and melamine resin are some instances of thermosetting resin. The present invention does not need to limit the softening temperature from 30 to 70° C. as required in Japanese patent application Laid- Open (Kokai) No. 1-205403 and can apply to thermosetting resin with softening point above 70° C. For good thermal durability, resin with softening point above 120° C., preferably above 150° C., is required.
Thermosetting resin used in the present invention must be solid state powder at room temperature. Solid state has advantage in supplying constant amount of powder into the mold and therefore the quality of product such as density, magnetic property and dimensions are kept constant. Solid state is also preferable from the standpoint of easy handling of the powder.
Small amount of additives can be mixed to the thermosetting resin as needed. The kind of additive is a lubricant chosen from zinc stearate, aluminum stearate, alcohol lubricant, and coupling agent such as silane coupling agent, titan coupling agent, and hardening agent such as 4.4'-diaminodiphenylsulfone (DDS), and cure accelerator such as TTP-S (trade name of a product of Hokko chemical Co.) These additives control the timing of molding, enhance the adhesion of melted resin to magnet powder, and provide easy mold release.
The compound is prepared by uniformly mixing 80-90 vol % of anisotropic magnetic powder and 10-20 vol % of thermosetting resin by kneading machine. If necessary 0.1-2.0 vol % of lubricant, hardening agent, cure accelerator, or coupling agent can be added.
In present invention not only a compound described above but those compounds described in Japanese patent application Laid- Open 2-27801, 4-349602 and 4-349603 in which the magnet powder coated by thermosetting resin or lubricant can be used.
Now the means to solve the contradiction of high density and magnet powder alignment is described in detail.
Molding apparatus used for the present invention is shown in FIG. 2 through FIG. 6. Controlling device of the mold temperature is shown in FIGS. 2 and 3. FIG. 2 shows a schematic illustration of a vertical magnetic field molding apparatus which consists of a die 22a with a built-in heater 22d, compression device 23 which apply pressure to the upper punch 22b and the lower punch 22c in vertical direction, and an electromagnet 21 which generates a magnetic field along the compression direction. The vertical magnetic field molding is applied for molding of ring magnets with radial magnetization or cylindrical magnets with axial magnetization.
FIG. 3 shows schematic illustration of a horizontal magnetic field molding apparatus which consists of a die 22a with a built-in heater 22d, compression device 23 which applies pressure to the upper punch 22b and the lower punch 22c in a vertical direction, and an electromagnet 21 which generates a magnetic field at right angles to the compression direction. The horizontal magnetic field molding is for rectangular parallelepiped magnets or ring magnets with axial magnetization.
FIG. 4 shows a horizontal magnetic field molding apparatus which has a rotary pump 24 to evacuate gases contained in the melted resin by reducing the pressure inside the mold via die 22a.
FIG. 5 shows a molding apparatus which has ultrasonic oscillatior 25 to apply ultrasonic vibration inside the mold which consists of the die 22a, upper punch and lower punch in addition to the apparatus shown in FIG. 4.
FIG. 6 shows a schematic illustration of a molding apparatus which consists of a die 22a with a built-in heater 22d, compression device 23 which applies pressure to the upper punch 22b and the lower punch 22c in a vertical direction, an electromagnet 21 which generates a magnetic field along the compression direction and a coreless coil 26 around the die 22a to generate a static magnetic field above 10 kOe or a pulse magnetic field above 10 kOe, preferably a pulse magnetic field above 25 kOe.
After filling the compound into the mold at a set temperature, a magnetic field is started to apply to align the magnetization of the powder. The thermosetting resin in the compound filled in the mold is gradually melted into liquid from solid state. In the alignment process the degree of magnetic alignment is determined by the readiness of rotation and movement of the magnet particles in the liquid resin and by the intensity and time duration of applied magnetic field. Theoretically all magnetizing directions of the powder are aligned unidirectionally.
In FIGS. 7 and 8 models for the state of magnetization direction of the powder in liquid resin 36 which is melted by heater 31 before and after magnetic alignment process are shown. FIG. 7 shows before the application of magnetic field by the electromagnet 32, FIG. 8 after the application of field. The direction of magnetic field 33 is at right angles to the direction of vertical compression 34. Magnetization of the powder is aligned from random direction 35a in FIG. 7 before application of the magnetic field to unidirection 35b which is the same direction as the applied magnetic field 33 in FIG. 8. FIG. 8 shows 100% of alignment in which all magnetizations are aligned unidirectionally.
To obtain high degree of alignment it is important to increase mobility of magnet powder when a magnetic field is applied. The highest mobility in the liquid resin are obtained when the viscosity of resin is lowest.
The viscosity of the melt resin (ρ) is a function of both heating temperature (T) and heating time (t). It is measured by Curelastometer or flow tester. The heating time for minimum viscosity at a given heating temperature is obtained by the function above.
FIG. 9 shows time dependency of the melt thermosetting epoxy resin viscosity at heating temperatures of 100, 120, 160, and 180° C. It is seen that less heating time is required for minimum viscosity (ρ min) as the heating temperature increases. At minimum viscosity the highest degree of alignment is obtained. Also applying pressure to densify the magnet at minimum viscosity range brings less disturbance in alignment compared to the alignment obtained at more viscous state. The reason is that the pressure becomes hydrostatic in liquid.
Application of a magnetic field requires a certain duration of time to obtain good magnetic alignment. It is because the viscosity of resin shows minimum after certain time at given heating temperature as seen in FIG. 9. Thus magnetic field application should be started right after filling the mold and should be kept while thermosetting resin softens and melt into liquid state. It must be kept after loading of the pressure which is started at the moment of lowest viscosity, in order to overcome disturbance caused by pressure.
Application of high intensity of magnetic field is required for high degree of magnetic alignment. In present invention more than 10 kOe of static magnetic field is required. It is because that a magnetic field of less than 10 kOe is insufficient in aligning powder magnetization. Similarly for applying pulse magnetic field, a magnetic field more 10 kOe is necessary. In this case more than 25 kOe is desirable.
It is favorable to apply ultrasonic vibration with frequency of 20 to 50 kHz to obtain high degree of alignment. A frequency below 20 kHz can not oscillate magnet particles in viscous melt resin sufficiently. A frequency above 50 kHz can not give enough magnitude of amplitude to the powder and thus efficiency of energy transmission to the magnet powder is lowered.
In compression molding with magnetic field, pressure is an important factor to improve the magnetic property of the bonded magnet by means of achieving highdensity. A greater molding pressure provides higher density of bonded magnet, although the lifetime of the mold is shortened. In the present invention the required pressure is between 4.0 and 10.0 ton/cm 2 , preferably between 6.0 and 8.0 ton/cm 2 . At a pressure below 4.0 ton/cm 2 it is not possible to obtain desired density and the magnetic property. On the other hand at a pressure above 10.0 ton cm 2 the life of the mold decreases drastically. Furthermore degassing the air contained in compound or the generated gas by melting is required to achieve higher density. Degassing is applied at either stage described as follows. One is to apply degassing after preforming a compact at low pressure and before melting by heating. The other is to apply degassing from liquid resin after melting. For the latter case, a molding apparatus shown in FIG. 4 is used.
In the former case of degassing from preformed compact before melting, preforming is carried out at a pressure of 1.0-4.0 ton/cm 2 after filling a compound into the mold. At a pressure below 1.0 ton/cm 2 degassing effect is not notable. On the other hand at a pressure above 4.0 ton/cm 2 degassing becomes ineffective because the gas is trapped in the preformed compact.
In the later case of degassing from melt resin, gases generated in melting process and adsorbed on the surface of magnet powder is removed as the powder rotates and moves by applied magnetic field in the melt resin.
It is desirable that the gas bubbles in the melt resin is degassed by evacuating inside the mold to vacuum. The pressure is set to be 10-500 torr. for degassing. At a pressure below 10 torr. it is not desirable because evacuation of melt resin occurs as well as the gas. On the other hand at a pressure above 500 torr. degassing does not proceed.
After compression molding with applied magnetic field curing is performed by maintaining the elevated temperature. In this invention molding process united with curing process offers two advantages. One is to increase production rate. Another is to keep close dimensional tolerances of bonded magnet because it is cured in the mold free from dimensional changes. Needless to say that curing may be done after taking a magnet from the mold and put into a curing furnace.
Now the characteristics of the bonded magnet produced by the present invention are described.
Theoretical limit of maximum energy product of a bonded magnet is determined by the maximum energy product and volume fraction of magnet powder. The intrinsic maximum energy product of powder is noted as X (MGOe), so that the maximum energy product of fully densified sinterd magnet X100 equals to X. The maximum energy product of bonded magnet in which the volume fraction of magnet powder is V (vol. %) is noted as Xv (MGOe).
FIG. 10 shows an ideal magnetic property of a fully densified magnet which consists of 100 vol % of magnet powder. Applied field (H) is taken as abscissa and magnetization (M) and magnetic flux density (B) as ordinate. Thick lines show B-H curve and thin lines M-H curve. In the figure, the area 51a in second quadrant gives the area (X100 ) of maximum energy product ((BH)max).
FIG. 11 shows a magnetic property of bonded magnet which consists of Vvol % of magnet powder and (100-V) vol % of resin powder. The magnetization of the bonded manget decreases by the magnetization (M) corresponds to (100-V) % of resin powder compared to that of the magnet with 100 vol % of magnet powder. As a consequence, B in B-H curve decreses. In the figure, the area 52a gives the area (Xv) of maximum energy product ((BH)max) for the bonded magnet. As seen in the figure, the maximum energy product ((BH)max) of the bonded magnet is proportional to the square of the volume fraction of the magnet powder in the magnet. The present invention offers maximum energy product above 80% of Xv for bonded magnets. ##EQU1## Where, V1 denotes volume fraction of magnet powder in a bonded magnet, and take value between 80 and 90%. X1 denotes maximum energy product of magnet powder and X1 is desirable to be more than 30 MGOe.
The maximum energy product of the anisotropic bonded magnet is desirable to be more than 20.0 MGOe.
The present invention offers high degree of magnet powder alignment and high volume fraction of magnet powder by applying both magnetic field and pressure at the moment when the resin is melted into liquid state in the compression molding using anisotropic magnet powder. It also offers high density by degassing the air contained in compound or the generated gas by melting. Furthermore, good alignment of magnet powder is given by application of ultrasonic vibration and pulse magnetic field. As a consequence a anisotropic bonded magnet with more than 80% of theoretical limit of maximum energy product is produced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows principle of the invention.
FIG. 2 shows schematic diagram of vertical magnetic field compression molding apparatus with heating system.
FIG. 3 shows schematic diagram of horizontal magnetic field compression molding apparatus with heating system.
FIG. 4 shows schematic diagram of horizontal magnetic field compression molding apparatus with degassing and heating system.
FIG. 5 shows schematic diagram of horizontal magnetic field compression molding apparatus with degassing ultrasonic vibrating and heating system.
FIG. 6 shows schematic diagram compression molding apparatus with pulse and steady magnetic field apply system and heating system.
FIG. 7 shows direction of magnetization of the magnet powder in the heated mold before magnetic field application.
FIG. 8 shows direction of magnetization of the magnet powder in the heated mold after magnetic field application.
FIG. 9 shows time dependency of viscosity of the liquid epoxy resin at given temperatures.
FIG. 10 shows (BH)max on BH curve of the magnet consist of 100% magnet powder (for example, sintered magnet).
FIG. 11 shows (BH)max on BH curve of the magnet consist of V % magnet powder and (100-V) % resin.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments according to the present invention will be described.
First, preparation method of the compound is given as follows.
Compounds were prepared by mixing magnet powder and thermosetting resin in a set ratio. As for magnet powder, four kinds of powder were used: high Co containing NdFeB type by HDDR treatment, low Co containing NdFeB type by HDDR treatment, SmFeN type mechanically ground after nitriding, and ground SmCo type magnet. As for thermosetting resins, two kinds were prepared to mix with above four kinds of magnet powder.
The preparation method of the thermosetting resin is given as follows. Epoxy resin powder (trade name Epicoat 1004 manufactured by Shell Epoxy Co.) as a main powder, diaminodiphenylmethane (DDM, a product of Wako Pure Chemical Co.) as hardening agent at a ratio of 0.05 against epoxy resin powder weight of unity, TPP-S (trade name of product of Hokko Chemical Co.) as cure accelerator at a ratio of 0.02 against epoxy resin powder weight of unity, and Hext S (trade name of a product of Hext Japan Co.) as internal mold releasing agent at a ratio of 0.022 against epoxy resin powder weight of unity were blended at an elevated temperature and then crushed into compound powder, then 0.5 wt. % of coupling agent was added. Hereafter this compound will be referred as compound A.
By similar manner, a powder using low-molecular-weight epoxy resin powder (trade name Epicoat 801 manufactured by Shell Epoxy Co.) was prepared. Hereafter this compound will be referred as compound B. Compound A is used in the embodiments 1-a to 6-2-c and compound A and B were used in the embodiment 7-a, b, respectively.
Next, the preparation method of the four kinds of magnet powders will be described in order of high Co containing NdFeB type, low Co containing NdFeB type, SmFeN type, and SmCo type magnet powder.
High Co containing NdFeB type alloy with a composition of Nd 12 .5 Fe 59 .1 Co 20 .5 B 6 .1 Ga 1 .8 was melted in a 30 kg VIM (vacuum induction melting) furnace and cast into an ingot. The ingot was heat-treated for the soaking time of 40 hour at 1100° C. in 200 torr. argon pressure in vacuum furnace, then crushed into lumps with about 30 mm diameter. The material was subjected to HDDR treatment in which hydrogenation at 800° C. for three hours at pressurized hydrogen atmosphere of 13 kg/cm 2 , desorption at 800° C. for 1 hour in a vacuum of 3×10-5 torr., and qenching were carried out. As a result, aggregation of fine powder was obtained. It was lightly ground in a mortar, ground in n-hexane in a ball mill, and classified into a powder with below 212 μm grain.
The magnetic properties of the powder obtained in the above manner measured by VSM (vibrating sample magnetometer) were as follows: maximum energy product (BH)max is 36.0 MGOe, residual magnetic flux Br 12.8 kG, and coercive force iHc 11.5 kOe. Hereafter the powder will be referred to as NdFeBtype magnet powder P1H.
Low Co containing NdFeB type allow has a composition of Nd 12 .3 Fe 76 .0 Co 5 .0 B 6 .0 Ga 0 .5 Nb 0 .2. It was melted in a 30 kg VIM furnace and casted into an ingot. The ingot was heat-treated for the soaking time of 40 hour at 1100° C. in 200 torr. rgon pressure in vacuum furnace, then crushed into lumps with about 30 mm diameter. The material was subjected to HDDR treatment in which hydrogenation at 800° C. for three hours at pressurized hydrogen atmosphere of 0.4 kg/cm 2 , desorption at 800° C. for 1 hour in a vacuum of 5×10- -5 torr., and quenching were carried out. As a result, aggregation of fine powder was obtained. It was lightly ground in a mortar, ground in n- hexane in a ball mill, and classified into a powder with below 212 μm grain.
The magnetic properties of the powder obtained in the above manner measured by VSMare as follows: maximum energy product (BH)max is 40.0 MGOe, residual magnetic flux Br 13.2 kG, and coercive force iHc 14.0 kOe. Hereafter the powder will be referred as NdFeB type magnet powder P1L.
SmFeN type alloy has the chemical composition of the magnet powder was Sm 9 .0 Fe 77 .0 N 13 .6. An alloy with a chemical composition of Sm 12 .0 Fe 88 .0 was melted in a 30 kg VIM furnace and cast into an ingot. The ingot was crushed into lumps with about 30 mm diameter, nitrided at 450° C. for three hours in ammonia decomposed gas, heat-treated at 450° C. for 1 hour in argon atmosphere to homogenize nitrogen concentration, then ball-milled in n-hexane into powder with the diameter from 1 to 3 μm.
The magnetic properties of the powder obtained in the above manner measured by VSM are as follows: maximum energy product (BH)max is 35.0 MGOe, residual magnetic flux Br 13.0 kG, and coercive force iHc 8.8 kOe. Hereafter the powder will be referred to as NdFeB type magnet powder P2.
SmCo type alloy has a composition of Sm 10 .8 Co 54 .5 Cu 6 .2 Fe 25 .9 Zr 2 .7. It was melted in a 30 kg VIM furnace and cast into an ingot. The ingot was homogenized at 1180° C. for a soaking time of 30 hour in argon atmosphere, aged at 800° C. f 24 hour in argon atmosphere, and then mechanically crushed into lumps with about 30 mm diameter, ball-milled in n-hexane into a powder with the diameter below 30 μm.
The magnetic properties of the powder obtained in the above manner measured by VSM are as follows: maximum energy product (BH)max is 31.0 MGOe, residual magnetic flux Br 12.0 kG, and coercive force iHc 11.5 kOe. Hereafter the powder will be referred as NdFeB type magnet powder P3.
These examples and comparative examples were formed to a rectangular parallelepiped with the size of 10×10×7 mm.
EXAMPLE 1 SERIES
The example 1-a, 1-b, 1-c were manufactured with NdFeB type magnet powder (P1H), SmFeN type (P2), and SmCo type (P3) as for magnet powder, respectively.
The magnet powder and the thermosetting resin (A) were mixed into compounds to the ratio of 83 volume % and 17 volume %, respectively. Compression molding was carried out with a horizontal magnetic field molding apparatus as shown in FIG. 11b in the following manner.
The compound was filled in the mold which temperature was kept to 150° C. A magnetic field of 16 kOe as applied after filling the mold. Compression was started 15 seconds after starting the application of the magnetic field at a pressure of 8.0 ton/cm 2 . After 24 seconds of compression, application of magnetic field and compression were stopped.
In the process, the thermosetting resin was melted by keeping the temperature of the mold to 150° C. When its viscosity is the lowest, the magnetization of the powder is aligned in a short duration of time and at the same time the composite of melted resin and the magnet powder is densified. Then magnetic field application and the compression were stopped when crosslinking of the resin had proceeded and the viscosity started to increase. At last the bonded magnet was taken out from the mold and cured at 150° C. fr 30 minutes.
These examples, and comparative example 1 and 2, were formed to a rectangular parallelepiped with the size of 10×10×7 mm.
Comparative example 1-1 compared to example 1 was manufactured in the same manner as that of example 1 except the molding temperature was kept at room temperature.
Comparative example 1-2 compared to example 1 was manufactured in the same manner as that of example 1 except the molding temperature was kept at 70° C. andcompression time of 30 seconds.
The maximum energy product (BH)max of example 1-a,b,c, comparative example 1-1-a,b,c, and 1-2-a,b,c are shown in table 1. The values in the parentheses are the rate in percent to the theoretical value for the given anisotropic magnet powder.
TABLE 1______________________________________ type of magnet NdFeB type bonded SmFeN type SmCo type magnet bonded magnet bonded magnetexample maximum energy product (BH)max (MGOe)______________________________________example 1 19.8 19.5 17.1 (80%) (81%) (80%) comparative 12.0 10.0 9.0 example 1-1 (48%) (42%) (42%) comparative 13.0 10.5 9.5 example 1-2 (53%) (44%) (44%)______________________________________
As shown in table 1, the maximum energy product of about 20 MGOe was obtained for the NdFeB type and SmFeN type, and about 17 MGOe for SmCo type bonded magnet. Example 1-a,b,c are superior to the comparative examples in all types of magnets. Furthermore, all values for examples are attained more than 80% of their theoretical value while comparative examples have only 42-63% of theoretical value. These results show that the present invention brings high magnet powder alignment to bonded magnets.
EXAMPLE 2 SERIES
The compound and the apparatus are the same as those of example 1 series.
The compound was filled in the mold which temperature was kept to 150° C. then preformed at a pressure of 3.0 ton/cm 2 . A magnetic field of 16 kOe was applied after filling the mold. Compression was started 15 seconds after starting the application of the magnetic field at a pressure of 8.0 ton/cm 2 . After 24 seconds of compression, application of magnetic field and compression were stopped.
Then the bonded magnet was taken out from the mold and cured at 150° C. for 30 minutes.
The preformed compound was given to compression molding in the same manner as the example 1 series were compression-molded except the molding temperature was kept at room temperature and the compression time was 30 seconds.
Then the bonded magnet was taken out from the mold and cured at 150° C. for 30 minute similar to example 1 series.
The maximum energy product (BH)max of example 2-a,b,c, comparative example 2-a,b,c are shown in table 2. The values in the parentheses are the rate in percent to the theoretical value for the given anisotropic magnet powder.
TABLE 2______________________________________ type of magnet NdFeB type bonded SmFeN type SmCo type magnet bonded magnet bonded magnetexample maximum energy product (BH)max (MGOe)______________________________________example 1 20.0 20.0 17.4 (81%) (84%) (82%) comparative 12.0 10.0 9.0 example 1-1 (49%) (42%) (42%)______________________________________
As shown in table 2, the values of example 2-a,b,c are improved by 0.0-0.5 MGOe from those of example 1-a,b,c, respectively, while the values of comparative example 2 series remain the same as those of the comparative example 1-1 series. It is presumed that bridging of the magnet powder is suppressed by preforming so that high density is attained, because the improvement is notable in SmFeN type bonded magnet which has finer particle powder susceptible for bridging. Also, in compression molding at room temperature the improvement by preforming is not seen.
Furthermore, all values for examples are attained 81-84% of their theoretical value while comparative examples have only 42-49% of theoretical value. These results show that the present invention brings high magnet powder alignment to bonded magnets.
EXAMPLE 3 SERIES
The compound and the apparatus are the same as those of example 1 series.
The magnets were manufactured in the same manner as example 1 series except they were cured in the mold at the temperature of 150° C. for 5 minutes without taking out from the mold. During the curing the pressure was kept to 8.0 ton/cm 2 . Comparative example 3 series were manufactured in the same manner as example 1 series. They were taken out from the mold and curing was carried out at the temperature of 150° C. for 30 minutes.
The maximum energy product (BH)max of example 3 series, and comparative example 3 series are shown in table 3.
TABLE 3______________________________________ type of magnet NdFeB type bonded SmFeN type SmCo type magnet bonded magnet bonded magnetexample maximum energy product (BH)max (MGOe)______________________________________example 3 19.7 19.6 17.0 comparative 19.8 19.4 17.2 example 3remarks none of the example 3 and comparative example 3 shows any crack or chipping-off______________________________________
As shown in table 3, the maximum energy product of the obtained magnets are equivalent in same type of magnet regardless of the difference in curing process. Also, all magnets show no crack nor chip-off. However curing in the mold saves successive curing step and reduce curing time from 30 minutes to 5 minutes.
EXAMPLE 4 SERIES
In these examples the compound used is same as that of example 1 series. As the molding apparatus the one with degassing system shown in FIG. 4 was used.
The compound was filled in the mold which temperature was kept to 150° C. A magnetic field of 16 kOe was applied after filling the mold. Compression was started 15 seconds after starting the application of the magnetic field at a pressure of 8.0 ton/cm 2 . At the same time degassing was started by reducing the pressure inside the mold. The pressure was reduced to 450 torr by rotary pump. The degassing, the magnetic field and compression were applied simultaneously at the temperature of 150° C. They were stopped when crosslinking of the resin had proceeded and the viscosity started to increase. Then the bonded magnet was taken out from the mold and cured at 150° C. for 30 minutes.
The maximum energy product (BH)max of example 4 series are shown in table 4.
TABLE 4______________________________________ type of magnet NdFeB type bonded SmFeN type SmCo type magnet bonded magnet bonded magnetexample maximum energy product (BH)max (MGOe)______________________________________example 4 20.2 20.5 17.6 (83%) (84%) (83%)______________________________________
As shown in table 4, maximum energy product of bonded magnets are improved by degassing to the extend of 0.4-1.0 MGOe. The obtained values are 83-84% of their theoretical value and superior to those of example 1 by as much as 3%.
These results shows that the degassing brings high density to bonded magnets.
EXAMPLE 5 SERIES
In these examples the compound used is the same as that of example 1 series. As the molding apparatus the one with degassing and ultrasonic vibration system shown in FIG. 5 was used.
The compound was filled in the mold which temperature was kept to 150° C. A magnetic field of 16 kOe was applied after filling the mold. At the same time ultrasonic of 20 kHz was started to apply. Compression was started 15 seconds after starting the application of the magnetic field at a pressure of 6.5 ton/cm 2 . The magnetic field and compression were applied simultaneously at the temperature of 150° C. They were stopped when crosslinking of the resin had proceeded and the viscosity started to increase. Then the bonded magnet was taken out from the mold and cured at 150° C. for 30 minutes.
The maximum energy product (BH)max of example 5 series are shown in table 5.
TABLE 5______________________________________ type of magnet NdFeB type bonded SmFeN type SmCo type magnet bonded magnet bonded magnetexample maximum energy product (BH)max (MGOe)______________________________________example 5 21.1 20.7 17.8 (85%) (86%) (84%)______________________________________
As shown in table 5, maximum energy product of bonded magnets are improved by ultrasonic vibration to the extent of 0.7-1.3 MGOe. The obtained values are 84-86% of their theoretical value and superior to those of example 1 by as much as 4-5% These results show that the ultrasonic vibration brings high density and high magnet powder alignment to bonded magnets.
The ultrasonic vibration brings another advantage that the molding pressure can be reduced from 8.0 to 6.5 ton/cm 2 to obtain the same level of maximum energy product as that of example 1 series and the lifetime of the mold is extended.
EXAMPLE 6 SERIES
In this series example 6-1-a,b,c were manufactured with pulse magnetic field and example 6-2-a,b,c with pulse field superimposed on steady magnetic field applied. Vertical molding apparatus used for the example 6-1-a,b,c is shown in FIG. 2.
The compound was filled in the mold which temperature was kept to 150° C. 1 second after the filling the mold repeated pulse magnetic field of 50 kOe was started to apply. One cycle of the pulse consists of applied time of 0.1 sec. and the interval of 2 sec. At the same time compression was started. The compression molding was carried out at the pressure was 8.0 ton/cm 2 . The magnetic field and compression were applied simultaneously at the temperature of 150° C. They were stopped when crosslinking of the resin had proceeded and the viscosity started to increase. Then bonded magnet was taken out from the mold and cured at 150° C. for 30 minute.
Example 6-2-a,b,c were manufactured in the same manner as the example 6-1-a,b,c except the applied magnetic field was steady field of 16 kOe superimposed on pulse magnetic field of 50 kOe.
The comparative sample 4 series were manufactured without applying pulse magnetic field but steady field of 16 kOe.
The maximum energy product (BH)max of example 6-1-a,b,c, 6-2-a,b,c and comparative example 4-a,b,c are shown in table 6.
TABLE 6______________________________________ type of magnet NdFeB type bonded SmFeN type SmCo type magnet bonded magnet bonded magnetexample maximum energy product (BH)max (MGOe)______________________________________example 6-1 1.3 17.7 15.3 example 6-2 17.9 18.0 15.8 comparative 17.0 17.2 15.0 example 4______________________________________
As shown in table 6, the maximum energy product of the example 6-1a,b,c, which are manufactured with pulse field, are greater than that of example 4-a,b,c, which is with steady field, to the extent of 0.3-0.5 MGOe, respectively. The maximum energy product of examples 6-2-a,b,c which are manufactured with pulse field superimposed on steady field, are greater than that of examples 4-a,b,c, which is with steady field, to the extent of 0.8-0.9 MGOe, respectively.
EXAMPLE 7
Examples 7-a was manufactured with NdFeB type magnet powder (P1L) as the magnet powder and resin (A) as thermosetting resin. The magnet powder (P1L) and the thermosetting resin (A) were mixed into compounds to the ratio of 83 volume % and 7 volume %, respectively.
Examples 7-b was manufactured with NdFeB type magnet powder (P1L) as the magnet powder and resin (B) as thermosetting resin. The magnet powder (P1L) and the thermosetting resin (B) were mixed into compounds to the ratio of 83 volume % and 17 volume %, respectively.
The molding apparatus and manufacturing conditions were the same as for example 1 series except for the molding pressure increased to 8.5 ton/cm 2 .
The maximum energy product (BH)max of example 7-a,b are shown in table 7.
TABLE 7______________________________________ type of resin thermosetting resin (A) thermosetting resin (B) (Epicoat 1004) (Epicoat 801)example maximum energy product (BH)max (MGOe)______________________________________example 7 20.7 23.0______________________________________
As shown in table 7, example 7-a has maximum energy product of 20.7 MGOe which is higher than that of example 1-a. This is due to the high molding pressure. Example 7-b has the highest maximum energy product of 23.0 MGOe among those in example 1 to 6 series. This is due to the low molecular weight resin powder used in example 7-b.
The present invention offers anisotropic boned magnet with excellent magnetic property, more specifically more than 80% of theoretical value of maximum energy product for a given volume fraction V % of magnet. As a result, bonded magnets with the maximum energy of more than 20 MGOe are obtained.
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Compression molding suitable anisotropic magnet powder had not been established facing the difficulty of contradiction of high density and magnet powder alignment. By applying both magnetic field and pressure at the moment when the resin is melted into liquid state by heating, both high density and a high degree of magnet powder alignment are attained. Furthermore, application of degassing and ultrasonic vibration were found to be effective. An anisotropic bonded magnet with the maximum energy of more than 20 MGOe, in other words, more than 80% of the theoretical value of maximum energy product, is obtained.
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FIELD OF THE INVENTION
The invention relates to microcellular polyurethane elastomers and a process for making them. The elastomers are valuable for a variety of uses, most notably in automotive applications and footwear.
BACKGROUND OF THE INVENTION
Microcellular polyurethane elastomers are well known. They have fine, evenly distributed cells, and densities that are low compared with solid urethane elastomers yet high compared with flexible polyurethane foam. Microcellular polyurethane elastomers are used in automotive parts (e.g., bumpers and armrests), gaskets, vibration damping applications, and footwear.
While many ways to make microcellular polyurethane elastomers have been revealed, most approaches fit into two categories: the "one-shot" method and the "prepolymer" method. In the one-shot method, all of the components (polyols, polyisocyanate, blowing agents, surfactant, catalyst, chain extenders) are combined and reacted in a single step. In contrast, the prepolymer approach pre-reacts the polyisocyanate with a polyol to make a "prepolymer" (the "A" side) that is subsequently combined with the remaining reactants including any chain extenders (the "B" side), in a second step to make the elastomer. As U.S. Pat. No. 4,559,366 illustrates, it can be beneficial to make a "quasiprepolymer" by using an by reacting the polyol with enough polyisocyanate to produce a mixture of isocyanate-terminated prepolymer and free polyisocyanate. Such quasiprepolymers are commonly used to boost the available NCO content of the "A" side.
It is also known to prepare prepolymers ("A" sides) from isocyanates and polyol-chain extender mixtures. For example, U.S. Pat. No. 5,658,959 teaches to make an isocyanate-terminated prepolymer from MDI, dipropylene glycol, a polyoxypropylated/ethoxylated glycerine, and a polyoxypropylated/ethoxylated glycol (see Example 1). The reference polyols have up to 35 wt. % of ethylene oxide content, but an undisclosed degree of "endcapping" or primary hydroxyl group content (see column 5, lines 17-38). The reference is also silent regarding the unsaturation level of the polyols. U.S. Pat. No. 5,618,967 contains a similar disclosure. In sum, these references suggest that neither the unsaturation level nor the primary hydroxyl content of the polyols is important.
U.S. Pat. No. 5,284,880 also shows (see, e.g., column 13, lines 30-45) a prepolymer made from an isocyanate, a polyol, and a chain extender (dipropylene glycol). This reference teaches, however, that the "A" side polyol must be a "polyether containing predominately secondary hydroxyl groups" (see Abstract; col. 2, lines 4-5; and col. 4, lines 28-54). This reference is also silent regarding any need for a low-unsaturation polyol.
The benefits of polyols with low levels of unsaturation (<0.020 meq/g) for polyurethanes generally and for microcellular polyurethane elastomers in particular are known. U.S. Pat. Nos. 5,677,413 and 5,728,745, for example, describe microcellular polyurethanes made from polyols having unsaturations less than about 0.010 meq/g. The '745 patent makes the elastomers by either the prepolymer method (see Example 8 and Table 6 of the reference) or by the one-shot approach (see Examples 9-11 and Table 8 of the reference). The prepolymers of Example 8 are reaction products of polyoxypropylene diols or triols with 4,4'-MDI. No chain extender is used to make the prepolymer. In Examples 9-11, high-primary, low-unsaturation polyols are used. The references teach several advantages of using low-unsaturation polyols, including good resilience, low compression set, and reduced shrinkage; these advantages are particularly important for shoe soles.
U.S. Pat. No. 5,106,874 teaches prepolymer and one-shot approaches to making noncellular elastomers from low-unsaturation polyols. The prepolymers are generally made by reacting polyoxyalkylene polyols with an excess of polyisocyanate. The reference teaches that chain extenders can be included in the prepolymer (column 7, lines 49-52). However, none of the actual examples includes a chain extender reacted into the "A" side, and no microcellular elastomers are made.
U.S. Pat. No. 5,696,221 teaches to make polyurethane/urea elastomers by reacting prepolymers with a chain extender. The prepolymers include a diol having a molecular weight less than 400 in addition to a low-unsaturation, polyoxypropylene diol. The reference does not disclose microcellular elastomers.
Despite the well-recognized benefits of using low-unsaturation polyols in formulating microcellular polyurethane elastomers, some problems remain with the conventional one-shot and prepolymer approaches. As noted in U.S. Pat. No. 4,559,366, the one-shot approach cannot easily be used with 4,4'-diphenylmethane diisocyanate (4,4'-MDI), a ubiquitous raw material for shoe sole elastomers, because it is not readily miscible with other reactants, and it solidifies at room temperature (see col. 1 of the reference).
The prepolymer approach, however, also has drawbacks. Formulating high-quality, low-density elastomers, especially ones that have densities less than 0.5 g/cm 3 , is difficult. An obvious way to reduce density is to increase the amount of blowing agent (usually water). However, this increases the urea content of the elastomer, reduces elongation, and reduces flexibility. Adding more chain extender into the "B" side helps to maintain good hardness at lower densities, but this can cause poor processability and premature phase separation. As Comparative Example 8 (below) shows, such products often have an undesirable incidence of surface defects and internal splitting.
While it is known to include some chain extender in the "A" side, little or nothing is known about the benefits of doing so in the context of making microcellular elastomers based on low-unsaturation polyols, particularly those having a high content of primary hydroxyl groups.
In sum, the industry would benefit from better ways to make microcellular polyurethane elastomers, especially low-density elastomers. A preferred approach would use the low-unsaturation polyols now known to confer significant physical property advantages to urethanes. A valuable process would be easy to practice, yet would overcome the drawbacks of the conventional one-shot and prepolymer methods, particularly in formulating low-density elastomers.
SUMMARY OF THE INVENTION
The invention is a breakthrough process that enables formulators of microcellular elastomers to achieve densities below 0.5 g/cm 3 without sacrificing good processing latitude or excellent elastomer properties. The process comprises reacting a resin component ("B" side) with an isocyanate-terminated prepolymer ("A" side), optionally in the presence of a blowing agent, a surfactant, and a catalyst. The resin component includes a first chain extender and a first high-primary, low-unsaturation polyol. The key component, however, is the prepolymer, which is made by reacting a polyisocyanate, a second high-primary, low-unsaturation polyol, and a second chain extender. The second chain extender reacted into the "A" side comprises from about 5 to about 60 equivalent percent of the total chain extender.
I surprisingly found that pre-reacting the right proportion of a chain extender component into an "A" side that also includes a high-primary, low-unsaturation polyol as part of the prepolymer is the key to making low-density (less than 0.5 g/cm 3 ) microcellular elastomers while avoiding problems with poor processing or inferior physical properties. The process is easy to practice, and provides lighter, high-quality polyurethane products, including protective sports equipment, arm rests or steering wheels for the auto industry, and midsoles or shoe soles for footwear.
DETAILED DESCRIPTION OF THE INVENTION
In the process of the invention, the resin component ("B" side) comprises a first high-primary, low-unsaturation polyol, and a chain extender.
Polyols useful in the process of the invention are prepared by ring-opening polymerization of cyclic ethers, and include epoxide polymers, oxetane polymers, tetrahydrofuran polymers, and the like. The polyols can be made by any desired method; however, the ultimate product must have both low unsaturation and a high content of primary hydroxyl groups. Preferred are polyether polyols made by polymerizing epoxides, especially propylene oxide and/or ethylene oxide. Particularly preferred are propylene oxide-based polyols that are capped or tipped with oxyethylene groups.
The polyol has a high content of primary hydroxyl end groups. Such polyols are normally made by tipping or capping the ends of an polyoxypropylene polyol with oxyethylene units. By "high-primary," we mean polyols having at least about 50% primary hydroxyl groups. More preferably, the polyols have at least about 65% primary hydroxyl groups; most preferred are polyols having at least about 75% primary hydroxyl groups. High primary hydroxyl group content is important; as Comparative Example 6 below shows, poor elastomers result when a low-primary polyol is used in the process of the invention.
The polyol also has low unsaturation. By "low-unsaturation," we mean less than about 0.02 meq/g of unsaturation as measured by standard methods, such as ASTM D-2849-69, "Testing of Urethane Foam Polyol Raw Materials." Preferred polyols have unsaturations less than about 0.01 meq/g; most preferred are polyols having unsaturations less than about 0.007 meq/g. Polyols with very low unsaturation levels are conveniently made via double metal cyanide catalysis as described, for example, in U.S. Pat. Nos. 5,470,813 and 5,482,908, the teachings of which are incorporated herein by reference.
The polyol preferably has an average hydroxyl functionality less than about 3. A more preferred range is from about 1.8 to about 3.0. In addition, the polyol preferably has a number average molecular weight within the range of about 500 to about 50,000. A more preferred range is from about 1000 to about 6000; most preferred is the range from about 2000 to about 6000.
The polyol preferably has an oxyethylene content of at least about 5 wt. %, more preferably from about 10 to about 20 wt. %, which can be present internally, as a tip, or as an endcap. Preferably, most of the oxyethylene content is located toward the end of the polyol to provide for the desirable high content of primary hydroxyl groups.
The high-primary, low-unsaturation polyol is typically the major component of the "B" side. Generally, it comprises at least about 40 wt. % of the resin component. A preferred range is from about 45 to about 90 wt. %, more preferably from about 50 to about 70 wt. % of the resin component.
The resin component also includes a chain extender. Useful chain extenders have at least two active hydrogens, and include low molecular weight diols, diamines, aminoalcohols, dithiols, or the like. Preferably, the chain extenders have number average molecular weights less than about 400, more preferably less than about 300. Diols are preferred chain extenders. Suitable chain extenders include, for example, ethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, 1,4-butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, neopentyl glycol, cyclohexanedimethanol, 1,6-hexanediol, ethylene diamine, ethanedithiol, and the like, and mixtures thereof. Particularly preferred are dipropylene glycol, ethylene glycol, and 1,4-butanediol. A minor proportion of chain extender having 3 or more active hydrogens (e.g., glycerine) can be included if desired.
The chain extender is a minor "B" side component. Typically, it comprises less than about 30 wt. % of the resin component. A preferred range is from about 1 to about 20 wt. %, more preferably from about 3 to about 10 wt. % of the resin component.
The resin component optionally includes additional polyols, which may or may not be low-unsaturation or high-primary polyols. Preferably, the resin component includes a polymer polyol. Suitable polymer polyols include the well-known variety prepared by in situ polymerization of vinyl monomers in a base polyol to give a stable dispersion of polymer particles in the base polyol, such as styrene-acrylonitrile (SAN) polymer polyols. Other suitable polymer polyols include PIPA and PHD polyols, which are--like the SAN polymer polyols--commercially available. These polymer polyols have polymer solids contents generally in the range of about 5 to about 50 wt. %. When a polymer polyol is included, it is preferred to use an amount within the range of 5 to about 45 wt. % based on the total amount of resin component.
An isocyanate-terminated prepolymer ("A" side) reacts with the resin component ("B" side) in the process of the invention. The prepolymer is the reaction product of a polyisocyanate, a second high-primary, low-unsaturation polyol, and a second chain extender.
The polyisocyanate is an aromatic, aliphatic, or cycloaliphatic isocyanate that contains at least two free NCO groups. Suitable polyisocyanates include diphenylmethane diisocyanates (MDIs), polymeric MDIs, MDI variants, toluene diisocyanates, hexamethylene diisocyanate, isophorone diisocyanate, and the like, and mixtures thereof. Preferred polyisocyanates are 4,4'-MDI, other MDI blends that contain a substantial proportion of the 4,4'-MDI isomer, and modified MDIs made by reacting MDI with itself of another component to introduce carbodiimide, allophanate, urea, urethane, biuret, or other linkages into the structure (MDI variants). Particularly preferred are 4,4'-MDI, carbodiimide-modified MDIs, and mixtures thereof. The amount of polyisocyanate used is preferably the amount needed to give an NCO-terminated prepolymer or quasiprepolymer having a free NCO content within the range of about 15 to about 30 wt. %, more preferably from about 20 to about 28 wt. %.
The prepolymer includes a second high-primary, low-unsaturation polyol, which may be the same as or different from the first high-primary, low-unsaturation polyol. The second polyol has the same general characteristics as the first, however, i.e., low unsaturation (less than about 0.02 meq/g) and a high content (at least about 50%) of primary hydroxyl groups. The high-primary, low-unsaturation polyol is a minor "A" side component. The isocyanate-terminated prepolymer preferably comprises from about 1 to about 10 wt. % of the prepolymer component; a more preferred range is from about 2 to about 8 wt. %,
The prepolymer also includes a chain extender. This chain extender (the "second" chain extender) may be the same as or different from the chain extender used in the resin component (the "first" chain extender). Otherwise, the second chain extender fits the above description of the first chain extender. The second chain extender, which is reacted into the "A" side, comprises from about 5 to about 60 equivalent percent of the total chain extender. Preferably, the second chain extender comprises from about 10 to about 40 equivalent percent of the total chain extender; a most preferred range is from about 15 to about 35 equivalent percent.
The amount of chain extender used to make the prepolymer is important. If less than about 5 equivalent percent is present, foam splitting, surface defects, and other problems result (see Comparative Example 8). On the other hand, if more than about 60 equivalent percent of the total chain extender is present in the "A" side, excessive heat can be generated, which can lead to unwanted gellation of the prepolymer.
While most prepolymers are simply reaction products of a polyisocyanate and a polyol, the present invention incorporates a chain extender into the prepolymer. I surprisingly found that pre-reacting 5 to 60 equivalent percent of the total chain extender into the "A" side, in combination with using a high-primary, low-unsaturation polyol, is the key to making low-density (less than 0.5 g/cm 3 ) microcellular elastomers while avoiding problems with poor processing or inferior physical properties. This simple step is crucial for providing lighter, high-quality polyurethane 1, products, particularly midsoles or shoe soles for footwear.
The prepolymer is generally made by combining the second polyol, second chain extender, and polyisocyanate in any desired order, and heating the mixture at a temperature and for a time effective to produce an isocyanate-terminated prepolymer. Usually, it is preferred to react the polyisocyanate and the high-primary, low-unsaturation polyol together for a short time before introducing the second chain extender. Heating then continues until the prepolymer reaches the desired content of free NCO groups. In another preferred mode, all or part of the second chain extender is included at the start of the prepolymer-forming reaction.
After the prepolymer has been made, it is combined with the resin component using conventional techniques to make the microcellular elastomer. The resin component is a well-blended mixture of the first low unsaturation polyol, the first chain extender, and other optional components such as blowing agents, surfactant, catalysts, and the like. The elastomers can be made by hand casting or machine. The "A" and "B" side components are combined, rapidly mixed, and injected or poured into open or closed molds. The formulations described herein are well suited for use with commercial equipment (such as the Gusbi molding machine) for making midsoles and shoe soles by closed molding techniques.
Preferably, the process of the invention is performed in the presence of a blowing agent. Suitable blowing agents are those well known in the art of formulating microcellular polyurethane elastomers. They include "physical" blowing agents, such as low-boiling halocarbons (e.g., CFCs, HCFCs, methylene chloride) or hydrocarbons (e.g., butane, pentane), inert gases (e.g., nitrogen, argon, carbon dioxide), or the like, and "reactive" blowing agents, such as water and other active-hydrogen compounds that react with NCO groups to liberate gases. Mixtures of blowing agents can be used. Water is a particularly preferred blowing agent. The blowing agent is used in an amount needed to produce a microcellular elastomer having a density of less than 0.5 g/cm 3 . Preferably, the resulting elastomer has a density within the range of about 0.02 to about 0.4 g/cm 3 ; most preferred is the range from about 0.1 to about 0.3 g/cm 3 .
The process optionally includes other conventional urethane foam components, such as surfactants, blowing catalysts, urethane-forming catalysts, pigments, UV stabilizers, crosslinkers, antioxidants, other polyols, and/or other additives. These optional ingredients are preferably mixed thoroughly with the resin component before reacting it with the "A" side to make the elastomer.
The process of the invention offers advantages for elastomer processing. "Moving" the right amount of chain extender into the "A" side component gives improved control over reactivity and flowability during elastomer processing because a significant fraction of the total reaction happens before the elastomer is formulated. The process also offers wide processing latitude. As the examples below demonstrate, excellent products can be made over a broad temperature range (40-60° C.) and a broad index range (95 to 105), and demold times are short (<7 min).
The process also offers physical property advantages. In the past, it was difficult to make microcellular elastomers with densities less than 0.5 g/cm 3 (especially ones with densities less than 0.3 g/cm 3 ) while avoiding problems with product quality. Microcellular elastomers made using the process of the invention have excellent tensile and tear strength, good skin quality, and no internal splits. As the examples below show, the process of the invention makes it possible to formulate--with ease--excellent elastomers
The following examples merely illustrate the invention. Those skilled in the art will recognize many variations that are within the spirit of the invention and scope of the claims.
EXAMPLES 1-5 and COMPARATIVE EXAMPLE 6
Preparation of Microcellular Polyurethane Elastomers
A Gusbi machine is used to mold 10-mm microelastomer plaques by reaction injection molding mixtures of the "A" and "B" -side components described below at 35° C. Mold temperatures are in the 40-60° C. range. The products are tack-free in less than one minute. Physical properties appear in Table 1.
As the table shows, microcellular elastomers with densities less than 0.27 g/cm 3 and an excellent balance of properties are available from the process of invention. In each example of the invention, the "A" side includes a chain extender (dipropylene glycol) and a high-primary, low-unsaturation polyol. Comparative Example 6 demonstrate s the importance of using a "high-primary" polyol. Low unsaturation alone is not enough to give good products at such low densities.
______________________________________FormulationResin component ("B" side) pbw______________________________________Low-unsaturation polyol (see Table 1) 58Polymer polyol.sup.1 35Water 1.1Ethylene glycol 5.2Dabco EG catalyst.sup.2 0.2X-8154 catalyst.sup.2 1.0BL-17 catalyst.sup.2 0.2T-120 catalyst.sup.2 0.02DC-193 surfactant.sup.3 0.25LK-221 emulsifier.sup.2 0.75Pigment (e.g., carbon black or TiO.sub.2) 1.2B-75 stabilizer.sup.4 1.0Prepolymer ("A" side; 24 wt. % NCO)4,4'-MDI 80Carbodiimide-modified MDI 8Low-unsaturation polyol (see Table 1) 5Dipropylene glycol 7______________________________________ .sup.1 SANtype, 43 wt. % solids content, hydroxyl number 20 mg KOH/g .sup.2 product of Air Products; .sup.3 product of Dow Corning; .sup.4 product of CibaGeigy.
TABLE 1______________________________________Microcellular Polyurethane ElastomersExample 1 2 3 4 5 C6______________________________________Resin polyol A-4220 A-4220 A-4220 A-2220 A-4220 A-3201Prepolymer A-4220 A-4220 A-4220 A-2220 A-2220 A-3201polyolA/B side (w/w) 0.53 0.55 0.58 0.55 0.55 0.55Index 0.95 1.00 1.05 1.00 1.00 1.00(NCO/OH)Physical PropertiesDensity 0.265 0.265 0.265 0.265 0.265 0.265(g/cm.sup.3)Hardness 61 62 62 60 60 58(Asker C)Tensile 19.4 20.8 23.2 16.4 19.2 *strength(kg/cm.sup.2)Elongation (%) 307 255 296 319 324 *Split tear 2.3 2.6 2.6 1.9 2.1 *(kg/cm,10 mm)______________________________________ A-4220 is Accuflex 4220 polyol, a polyoxypropylene diol having Mn = 4000, about 20 wt. % oxyethylene content (5% internal, 15% cap), and a primary hydroxyl group content of about 85%; A2220 is Accuflex 2220 polyol, a polyoxypropylene diol having Mn = 2000, about 20 wt. % oxyethylene conten (5% internal, 15% cap), and a primary hydroxyl group content of about 85% A3201 is Accuflex 3201 polyol, a #polyoxypropylene diol having Mn = 3000 about 10 wt. % internal oxyethylene content; all are products of ARCO Chemical. *Sample cracks and cannot be tested.
EXAMPLE 7
The procedure of Examples 1-5 is followed, except that the prepolymer is made using 52 parts of 4,4'-MDI, 4 parts of dipropylene glycol,and 3 parts of Accuflex 4220 polyol.
The resulting midsoles, which can be molded easily over a broad temperature range of 40 to 60° C., are excellent. Physical properties: density: 0.26 g/cm 3 ; Asker C hardness: 60-65; split tear strength: 2.0 kg/cm; tensile strength: 19 kg/cm 2 . Demold time is less than 7 min., and no skin peeling or internal splitting is evident.
COMPARATIVE EXAMPLE 8
In this example, all of the chain extender to be used is included in the resin component ("B" side).
The procedure of Example 7 is followed, with the following changes. The resin blend contains 1.5 parts of water and 12.5 parts of ethylene glycol. The prepolymer is made using 81 parts of 4,4'-MDI, 46 parts of Accuflex 4220 polyol, and no chain extender.
The resulting midsoles are poor. Physical properties: density: 0.26 g/cm 3 ; Asker C Hardness: 60-65 ;split tear strength: 1.6 kg/cm; tensile strength; 17 kg/cm 2 . Demold time is 7 min. or more. Many of the samples have poor skin quality, which is evident upon demolding. In addition, many of the parts have internal splits.
The preceding examples are meant only as illustrations; the following claims define the scope of the invention.
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Microcellular elastomers and a process for making them are disclosed. The process comprises reacting a resin component ("B" side) with an isocyanate-terminated prepolymer ("A" side). Pre-reacting the right proportion of chain extender into an "A" side that also includes a high-primary, low-unsaturation polyol is the key to making low-density (less than 0.5 g/cm 3 ) microcellular elastomers while avoiding problems with poor processing or inferior physical properties. The process is easy to practice, and provides lighter, high-quality polyurethane products, including protective sports equipment, arm rests or steering wheels for the auto industry, and midsoles or shoe soles for footwear.
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FIELD OF THE INVENTION
This invention relates to an internal combustion engine with cylinders arranged in a V configuration and a sound deadening jacketing of the engine body.
BACKGROUND OF THE INVENTION
It is an object of the present invention to provide a jacketing structure which is advantageous for engines of this kind and at the same time is compact, which can be produced and mounted in an economically viable fashion, which does not in any way obstruct the servicing of the engine, and finally ensures an optimum degree of muffling. These objects are achieved in accordance with the present invention by the fact that two carriers of plate form are gripped between the confronting parts of a cylinder housing and the outwardly projecting rims of said carriers constitute a frame which surrounds the engine body from all sides, a plurality of deadening shells conforming to the shape of the engine body bearing in sealed fashion against the same frame with the interposition of at least one vibration deadening insert, and these shells being secured to the body of the engine with the intermediary of spacer elements providing a vibration dampening support.
In the case of internal combustion engines with rows of cylinders arranged in V-formation and a blower which sends cooling air into the gap between the machine body and the jacketing, an advantageous arrangement is achieved by the fact that the sound deadening shell is arranged at each longitudinal side of the rows of cylinders in such a way that the free ends thereof extend to the lower zone of the crank case and defines with the side walls thereof an outlet slot for the cooling air.
A further advantageous form of the invention is achieved by the fact that all free standing outer walls of the crankcase are provided with at least a layer of sound deadening material directly applied thereto, and the two deadening shells arranged along the cylinder rows are equipped at their inner walls with a layer of sound deadening material. By this means a very long sound deadening trajectory or path is defined between the crankcase and the deadening shells, this trajectory reaching to the outlet slot and assisting in the high amount of reduction of the vibrations and noise at the outlet end of the cooling air conduction system of the engine. The deadening layer at the outer walls of the crankcase thus fulfills a second function, namely to reduce the radiation of body noise from these walls.
Another advantageous feature of the invention lies in the fact that the blower is arranged at a narrow side of the engine and the driving shaft of the blower wheel is mounted at the uppermost part in the gap between the V-form cylinder rows, the deadening shell at this side being provided with two inlet ports for cooling air. By this arrangement the cooling air is always inducted at the highest part of the engine so that scarcely any heavy polluted air can be drawn into the system.
It is advantageous in accordance with another feature of the invention that the two inlet ports are provided at their inner walls in each case with a layer of sound deadening material. An optimal effective long deadening run, with a deflection through 90°, is provided for in this way at the inlet side of the cooling air conduction system, without calling for any additional installation space.
In engines of the type which have concavity in the crank case for accommodating an externally mounted additional appliance, for example a starter, in an advantageous arrangement the concavity is closed by a cover which is provided with a layer of sound deadening material at its outer wall. By this means the deadening trajectory at the exhaust side of the cooling air conduction system is not retracted in any way by the concavity and therefore does not detrimentally affect the degree of muffling. Moreover, it reduces the radiation of sound from the starter itself.
A further feature of the invention provides that the air filter and the oil cooler are arranged inside the cover at the topmost part of the engine and are exposed directly to the air stream from the blower. Scarcely any grossly polluted air can then be passed to the air filter, and the oil cooler will therefore invariably receive compartively cool air.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a longitudinal section through the internal combustion engine;
FIG. 2 is a vertical cross section taken along the line II--II in FIG. 1;
FIG. 2A is a partially schematicized sectional view of only the platelike carriers and associated seal taken along the line IIA--IIA in FIG. 2;
FIG. 3 is a partial horizontal section taken along the line III--III of FIG. 2;
FIG. 4 is a side elevation seen in the direction of arrow A in FIG. 1; and
FIGS. 5 and 6 show details in section and on an enlarged scale.
DETAILED DESCRIPTION
The internal combustion engine which is illustrated in the drawings is an air cooled injection engine having eight cylinders inclined to the vertical and arranged in a conventional V-8 configuration. Th engine comprises a crankcase 10 having a crankshaft 12 rotatably mounted therein, the individual cylinders 14 with cylinder heads 16 and control gear covers 18 being connected to the crankcase 10 in a conventional manner. The fuel feed from a tank (not shown) is effected by an injection pump 20 driven by the crankshaft 12 and this pump 20 supplies fuel to the injection nozzle of each individual cylinder through a compression conduit. Combustion air is supplied through an air filter 22 which is connected to the inlet ports of the cylinders 14 through two pipes 24. Combustion gases are evacuated through two exhaust pipes 26.
A flywheel 28 is secured to one end of the crankshaft 12 and has fixing surfaces 28a and 28b for coupling means (not shown) used, in association with fastening screws (also not shown), for coupling the internal combustion engine to the plant which is to be driven.
Two oil coolers 30 are provided, one being associated with each bank or row of cylinders. In addition, en electric starter 32 is arranged externally in a concavity of the crankcase. These parts are of a known form and effect and, therefore, need not be further described.
The following arrangement has been developed for quieting the noise in this V-type engine caused by vibration of the parts.
The free external surfaces of the crankcase 10 have applied thereto, for example by cementing, sound deadening layers 34, 36, 38 conforming to the shape of these surfaces. An extension 40 of dished form connected to crankcase 10 to form an extension of the latter and enclosing the control gearing is also provided with a sound deadening layer 42.
The engine has a cooling air blower 45 of known type and this is arranged at the top between the two rows of cylinders. The shaft 44a of the rotor blower wheel 4 is driven from the crankshaft 12 through gearing in the manner illustrated. The casing 46 of the blower 45 is fastened to the crankcase 10 by means not illustrated, for example as by a flange and bolts securing the flange to the casing 10.
Moreover, two plate-like carriers 48 are provided, each one of which is secured between the cylinder head 16 and the cover 18 of the four cylinders of a V-row by the same means which are used to fasten the elements 18, 16, 14. Each carrier 48 has openings in the surface thereof for free passage of the various functioning parts. Outwardly directed rims 48a of the parts 48 are generally horizontally aligned (FIGS. 2 and 6) to encircle the body of the engine from all sides to define a frame, the rim parts being, for example, welded or soldered together. The rim, which is rectangular in shape externally has a fixed position in space, and thus also in relation to the various elements of the engine, because of the connection between the carriers 48 and the body of the engine. A sealing rib 50 of rubber or the like is pushed on to the outer rim 48a.
A cover sheet 52 is provided to cover all engine parts from above. The rectangular rim 52a thereof is secured to the sealing rib 50. The anchorage of the sealing rib 50 and cover sheet 52 to the engine body is explained below. In any event, the cover sheet 52 is readily releasable from the engine body.
The zone 52b (FIG. 4) of the cover sheet 52 enclosing the blower casing 46 is formed and shaped so as to be spaced closely to the periphery of the blower casing 46. The blower casing 46 is enclosed from below by the sheet part 58 having a deadening layer 58b thereon, this sheet being formed with two channels approximately tangential to the blower casing and having inlet ports 58a for the cooling and combustion air. The connection between the deadening shell 58, the sealing rib 50 and the crankcase 10 or the deadening layer 38 is preferably effected by adhesive means.
Spaced at a specific distance along each side of the crankcase 10 is an elongated deadening shell 60. A number of spacer elements 62,64 of rubber or the like are used to anchor the deadening shell to the crankcase 10. Preferably the elements 62,64 are cemented to the parts 60 and 10. The upper edge 60a of these shells 60 engage the sealing rib 50 and are thereby orientated in relation to the engine body. The lower edge of each shell 60 defines, with the outside of the crankcase 10, an open gap 60b thus providing two outwardly directed outlet slots for exhaust air. The cooling air which is drawn in by the blower 45 through the inlet ports 58a is directed against the cylinders of the two rows, flows over the hot outer parts thereof, and exits through the outlet slots 60b to the exterior.
The air filter 22 for the combustion air and the two oil coolers 30 are also arranged at the uppermost part of the engine approximately opposite the blower 45 and thereby exposed to the still relatively cool air flow from blower ports 44,46. The starter 32 is enclosed in the cavity 10a by means of a cover 70 which is connected in readily detachable fashion with the crankcase 10 (by means not shown). Cemented to the outer side of cover 70 is a deadening layer 70a which supplements the deadening layers of the crankcase 10. The two shells 60 are also provided internally with a deadening layer 60c. Thus, in this way there are very long sound deadening passages (that is to say, conduits equipped with sound deadening layers) both at the inlet and the outlet side of the cooling air blower. This produces a very high degree of sound muffling of all the noise which is produced in the engine. The jacketing of the crankcase 10 by sound deadening layers and the closure of the upper part of the machine by the cover sheet 52 together ensure that the noise radiated from the engine body itself is effectively muffled, even in the case of an internal combustion engine with a V-cylinder arrangement. Thus, parts of the deadening shells covering parts of the engine which require servicing are at the same time so devised that they can be readily dismounted for servicing purposes. The rim 48a of carrier 48 which is stationary, forms a base and carries the sealing means, further facilitates a replacement of the removed shells without difficulty in the correct position after the repair work or the like has been carried out.
When the shells 60 are detached, the spacer elements 62, 64 must be released from the engine body or from the wall 10 and re-cemented after repair or servicing of the engine. FIG. 5 shows that buffer elements, known per se, can be used for detachable anchorage of the shells 60. Such elements 162 made of rubber or the like are firmly connected to two metallic plates 162a and 162b, for example being vulcanized thereto. The buffer elements 162 are connected firmly to wall 10 by means of screws 164, while a screw 166 is used for detachable connection of the deadening shell 60,60c to the buffer 162.
Again, each cover plate could, for example, be connected in readily detachable fashion to the rim 48a through the agency of a manually operable closure flap. Another form of readily detachable construction is shown in FIG. 6. In this case, a number of spaced angle pieces 52w are secured to sheet 52, for example being welded to it. A number of angle pieces 60w are also welded to sheet 60. A very readily detachable anchorage of the cover sheet 52 to the engine is then achieved through the agency of screws 170 and spacer sleeves 168.
The exhaust pipes 26 may -- depending on specific requirements or differing engine constructions -- be guided directly to the exterior through the cemented deadening jacketing 42, or an arrangement can be so devised that the exhaust pipes 26 are directed towards the outlet slots 60b so that the combustion gases together with the hot cooling air stream can escape through these outlet slots.
Each of the deadening layers referred to above may, for example, consist of one or more layers of rock wool which are held together internally or externally with a thin foraminated covering of woven fabric or the like. The deadening layer is preferably secured to the associated surface by cementing through the agency of a heat resistant adhesive. Deadening layers of this nature are known per se and need not therefore be set out or illustrated in more detail at this juncture.
Finally, it is to be noted that the noise deadening jacketing of the machine only projects to an insignificant extent beyond the periphery of the engine and consequently does not call for any appreciable increase in the installation space for the jacketed engine.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.
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An internal combustion engine having the cylinders thereof arranged in a V-formation and having a sound deadening material jacketing the body of the engine. Two plate-like carriers are gripped between the confronting parts of the cylinder housing and the outwardly projecting rims thereof to constitute a frame which surrounds the engine body from all sides. A plurality of deadening shells conforming to the shape of the engine body bear in sealed fashion against the frame with the interposition of at least one vibration deadening insert. These shells are secured to the body of the engine with the intermediary of spacer elements providing a vibration dampening support.
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FIELD OF THE INVENTION
[0001] The present invention relates to an ink composition, suitable for use in an inkjet printing process.
BACKGROUND ART
[0002] Trimethylol-propane (TMP) is a well known co-solvent for use in aqueous inkjet inks. This kind of polar non-volatile polyhydric alcohols is commonly used as a stabilizing ink fraction to obtain print head jet-reliability. Moreover this particular compound effectively assists in preventing print media deformation of inkjet prints.
[0003] It was observed that also in latex-containing pigmented aqueous inks, i.e. aqueous inks comprising a dispersion of polymer particles (latex) and pigment particles, TMP acts as a stabilizing and a deformation-preventing co-solvent, even in the case of high speed/productive inkjet printing.
[0004] However, this co-solvent fraction also has to fulfill other requirements, like rheological and penetration properties of the ink on more or less absorbing media, i.e. a broad media range comprising plain papers, inkjet-coated and offset-coated media. Typically TMP-containing aqueous inks show a too low viscosity (i.e. to enable a stable ink-jet process) when using an effective amount of TMP from 10 weight % up to approximately 25 weight % and a functionally desired latex resin concentration of about 6 weight % together with approximately 4 weight % of one of the CMYK-pigments. All concentrations are indicated relative to the total weight of the ink composition.
[0005] It is a disadvantage of the prior art ink compositions that by increasing the latex-resin concentrations and/or the addition of thickening co-solvents like especially glycerol, to reach the optimal jet-viscosity of the ink required by the print head, provides ink recipes with lack of tolerance towards the mentioned media range to be printed on with good print quality and robustness.
[0006] It is therefore an object of the present invention to provide an ink composition that overcomes or at least mitigates the above stated disadvantage, i.e. to provide an ink composition that shows improved print robustness while maintaining print head reliability and print quality on a wide media range.
SUMMARY OF THE INVENTION
[0007] The object is at least partly achieved by providing an ink composition comprising a dispersion of resin particles in water (i.e. a latex), a colorant and a co-solvent fraction for stabilizing the dispersion, wherein the co-solvent fraction comprises at least one branched polyhydric alcohol and/or at least one (poly)ether modified branched polyhydric alcohol, and between 0.1 and 5 weight % polyvinylpyrrolidone having a weight average molecular weight of at least 5000 g/mol.
[0008] The inventors have found that if polyvinylpyrrolidone (PVP) is added to the basic recipe of latex-resin, colorant (e.g. a pigment), at least one branched polyhydric alcohol and/or at least one (poly)ether modified branched polyhydric alcohol, and water, the lack of tolerance regarding latex-resin concentration and thickening additives in view of the mentioned media range to be printed on improves, while retaining good print quality, adhesion and robustness on said media range. In this way robust look and feel films can be realized also on less absorbing media, like the offset coated gloss, silk and matt ones with a better freedom towards recipe variation of latex and the concentrations of the ingredients.
[0009] Without wanting to be bound to any theory it is believed that the good solubility of the branched polyhydric alcohol (e.g. TMP) and/or a (poly)ether modified branched polyhydric alcohol in the aqueous ink and its compatibility with the latex and pigment dispersion hinder a clean film separation and may cause inclusions of co-solvents into the film. The high molecular PVP apparently enhances the separative effect on the media gradually leading to clean film formation without such inclusions.
[0010] Furthermore, the addition of PVP increases the viscosity of the ink composition compared to the basic ink recipe, which provides design freedom of ink compositions in terms of concentration of latex particles, pigment particles and other additives that influence the viscosity (e.g. less latex, pigment and thickening additives are needed for obtaining an ink showing good jet reliability). Said components can therefore be used in functional amounts instead of in amounts needed for satisfying other ink criteria (e.g. the concentration of latex particles does not need to be increased to satisfy viscosity criteria of the ink composition).
[0011] In an embodiment, the co-solvent fraction further comprises at least one linear polyhydric alcohol.
[0012] In an embodiment, at least one linear polyhydric alcohol is selected from the group consisting of glycerol, 1,2,6-hexanetriol, diethylene glycol, triethylene glycol, tetra-ethylene glycol and dipropylene glycol.
[0013] Such linear polyhydric alcohols provide a longer nozzle open time (humectant function) and may also influence the viscosity of the ink composition, which may again be tuned with the PVP concentration in the ink composition.
[0014] In an embodiment, the at least one branched polyhydric alcohol and/or the at least one (poly)ether modified branched polyhydric alcohol comprises between 3 and 9 carbon atoms and 3 OH-groups.
[0015] In an embodiment, the at least one branched polyhydric alcohol and/or the at least one (poly)ether modified branched polyhydric alcohol satisfies the following formula:
[0000]
[0000] wherein:
R 1 , R 2 , R 3 and R 4 may be independently selected from —H; —OH; —CH 3 and —O—[CH 2 —CH 2 —O]—[CH 2 —CH(CH 3 )—O] q —[CH(CH 3 )—CH 2 —O] r —H, wherein p, q and r are integers selected independently of one another in a range of between 0 and 25; with the proviso that at least two of the R 1 -R 4 groups are independently of one another selected from the group consisting of —OH, and —O—[CH 2 —CH 2 —O] p —[CH 2 —CH(CH 3 )—O] q —[CH(CH 3 )—CH 2 —O] r —H, wherein p, q and r have the above described meaning.
[0016] In the present embodiment, —O—[CH 2 —CH 2 —O] p —[CH 2 —CH(CH 3 )—O] q —[CH(CH 3 )—CH 2 —O] r —H, represents a (poly)ether moiety comprising polyethyleneoxide groups (PEO, also termed ethoxylate groups) if p>0 and polypropylene oxide groups (PPO, also termed propoxylated groups) if q>0 and/or r>0.
[0017] In case q=0 and r=0, the (poly)ether moiety is a homopolymeric polyethyleneoxide group.
[0018] In case p=0, the (poly)ether moiety is a homopolymeric polypropylene oxide group.
[0019] In accordance with the present embodiment, the (poly)ether modification of the branched polyhydric alcohol may comprise substitution by a copolymeric group comprising ethylene oxide (EO) and propylene oxide (PO) moieties, these moieties may be arranged in a block copolymeric arrangement, in an alternating copolymeric arrangement, in a periodic copolymeric arrangement or in a random copolymeric arrangement.
[0020] In an embodiment, the at least one branched polyhydric alcohol and/or the at least one (poly)ether modified branched polyhydric alcohol has a number average molecular weight (M n ) of less than 1000 g/mol, preferably between 200 and 800 g/mol, more preferably between 200-600 g/mol.
[0021] If branched polyhydric alcohols and/or (poly)ether modified branched polyhydric alcohols having a number average molecular weight of more than 1000 g/mol are used, the ink absorption in the media may be disturbed.
[0022] In an embodiment, the at least one branched polyhydric alcohol is selected from the group consisting of trimethylol propane, trimethylol ethane, pentaerithritol and neopentylglycol.
[0023] In an embodiment, the at least one (poly)ether modified branched polyhydric alcohol is selected from the group consisting of: trimethylol propane ethoxylate, trimethylol ethane ethoxylate, pentaerithritol ethoxylate, neopentylglycol ethoxylate, trimethylol propane propoxylate, trimethylol ethane propoxylate, pentaerithritol propoxylate and neopentylglycol propoxylate.
[0024] In an embodiment, the polyvinylpyrrolidone has a weight average molecular (M W ) weight of at least 7500 g/mol, preferably at least 10000 g/mol, more preferably between 10000 g/mol and 30000 g/mol.
[0025] In an embodiment, the polyvinylpyrrolidone is present in an amount of between 0.2 and 3 weight %, preferably between 0.3 and 1.5 weight % relative to the total ink composition.
[0026] In an embodiment, the ink composition comprises:
[0000] 0.5-20 wt % of water dispersed resin particles;
0.5-15 wt % of a colorant;
5-20 wt % of at least one linear polyhydric alcohol;
5-30 wt % of at least one branched polyhydric alcohol and/or at least one (poly)ether modified branched polyhydric alcohol;
0.1-5 wt % polyvinylpyrrolidone having a weight average molecular weight of between 5000 g/mol and 30000 g/mol, wherein all amounts are relative to the total ink composition.
[0027] In an embodiment, the ink composition comprises:
[0000] 20-80 wt % water;
0.5-20 wt % of water dispersed resin particles;
0.5-15 wt % of a colorant;
5-20 wt % of at least one linear polyhydric alcohol selected from the group consisting of glycerol, 1,2,6-hexanetriol, diethylene glycol, triethylene glycol, tetra-ethylene glycol and dipropylene glycol;
5-30 wt % of a at least one branched polyhydric alcohol selected from the group consisting of trimethylol propane, trimethylol ethane pentaerithritol, neopentylglycol and/or at least one (poly)ether modified branched polyhydric alcohol selected from the group consisting of trimethylol propane ethoxylate, trimethylol ethane ethoxylate, pentaerithritol ethoxylate, neopentylglycol ethoxylate, trimethylol propane propoxylate, trimethylol ethane propoxylate, pentaerithritol propoxylate, and neopentylglycol propoxylate; and
0.1-3 wt % polyvinylpyrrolidone having a weight averaged molecular weight (M W ) of at least 7500 g/mol, wherein all amounts are relative to the total ink composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention will become more fully understood from the detailed description given herein below and accompanying schematical drawings which are given by way of illustration only and are not limitative of the invention, and wherein:
[0029] FIG. 1 shows a schematic representation of an inkjet printing system.
DETAILED DESCRIPTION
Ink Composition
[0030] An (aqueous) ink composition according to the present invention comprises a dispersion of resin particles in water (i.e. a latex), a colorant and a co-solvent fraction for stabilizing the dispersion, wherein the co-solvent fraction is a mixture of a linear polyhydric alcohol and a branched polyhydric alcohol, wherein the ink composition further comprises between 0.1 and 5 weight % polyvinylpyrrolidone having a weight average molecular weight of at least 10000 g/mol. The components of the inks will be described in detail in the next sections.
Dispersion of Resin Particles
[0031] The inkjet ink according to the present invention contains a water-dispersible resin in view of the pigment fixability to recording media. As the water-dispersible resin, a water-dispersible resin excellent in film formability (image formability) and having high water repellency, high waterfastness, and high weatherability is useful in recording images having high waterfastness and high image density (high color developing ability).
[0032] Examples of the water-dispersible resin include synthetic resins and natural polymer compounds.
[0033] Examples of the synthetic resins include polyester resins, polyurethane resins, polyepoxy resins, polyamide resins, polyether resins, poly(meth)acrylic resins, acryl-silicone resins, fluorine-based resins, polyolefin resins, polystyrene-based resins, polybutadiene-based resins, polyvinyl acetate-based resins, polyvinyl alcohol-based resins, polyvinyl ester-based resins, polyvinyl chloride-based resins, polyacrylic acid-based resins, unsaturated carboxylic acid-based resins and copolymers such as styrene-acrylate copolymer resins, and styrene-butadiene copolymer resins.
[0034] Examples of the natural polymer compounds include celluloses, rosins, and natural rubbers.
[0035] Examples of commercially available water-dispersible resin emulsions include: Joncryl 537 and 7640 (styrene-acrylic resin emulsion, made by Johnson Polymer Co., Ltd.), Microgel E-1002 and E-5002 (styrene-acrylic resin emulsion, made by Nippon Paint Co., Ltd.), Voncoat 4001 (acrylic resin emulsion, made by Dainippon Ink and Chemicals Co., Ltd.), Voncoat 5454 (styrene-acrylic resin emulsion, made by Dainippon Ink and Chemicals Co., Ltd.), SAE-1014 (styrene-acrylic resin emulsion, made by Zeon Japan Co., Ltd.), Jurymer ET-410 (acrylic resin emulsion, made by Nihon Junyaku Co., Ltd.), Aron HD-5 and A-104 (acrylic resin emulsion, made by Toa Gosei Co., Ltd.), Saibinol SK-200 (acrylic resin emulsion, made by Saiden Chemical Industry Co., Ltd.), and Zaikthene L (acrylic resin emulsion, made by Sumitomo Seika Chemicals Co., Ltd.), acrylic copolymer emulsions of DSM Neoresins, e.g. the NeoCryl product line, in particular acrylic styrene copolymer emulsions NeoCryl A-662, NeoCryl A-1131, NeoCryl A-2091, NeoCryl A-550, NeoCryl BT-101, NeoCryl SR-270, NeoCryl XK-52, NeoCryl XK-39, NeoCryl A-1044, NeoCryl A-1049, NeoCryl A-1110, NeoCryl A-1120, NeoCryl A-1127, NeoCryl A-2092, NeoCryl A-2099, NeoCryl A-308, NeoCryl A-45, NeoCryl A-615, NeoCryl BT-24, NeoCryl BT-26, NeoCryl XK-15, NeoCryl X-151, NeoCryl XK-232, NeoCryl XK-234, NeoCryl XK-237, NeoCryl XK-238-NeoCryl XK-86, NeoCryl XK-90 and NeoCryl XK-95 However, the water-dispersible resin emulsion is not limited to these examples.
[0036] The content of the water-dispersible resin added in the ink of the present invention is preferably from 1-40 weight % based on the total weight of the ink, and it is more preferably from 1.5-30 weight %, and it is still more preferably from 2-25 weight %.
[0037] Even more preferably, the amount of the water-dispersible resin contained in the inkjet ink, as a solid content, is 2.5 weight % to 15 weight %, and more preferably 3 weight % to 7 weight %, relative to the total ink composition.
[0038] In an embodiment, the ink composition according to the present invention comprises two or more water-dispersible resins selected from the above cited synthetic resins, synthetic copolymer resins and natural polymer compounds in admixture with each other.
Colorant
[0039] The colorant may be a pigment or a mixture of pigments, a dye or a mixture of dyes or a mixture comprising pigments and dyes.
[0040] In the inkjet ink according to the present invention, a pigment is primarily used as a water-dispersible colorant in view of the weatherability, and, for the purpose of controlling color tone, a dye may be contained within the range not impairing the weatherability. The pigment is not particularly limited and may be suitably selected in accordance with the intended use.
[0041] Specific pigments which are preferably usable are listed below.
[0042] Examples of pigments for magenta or red include: C.I. Pigment Red 1, C.I. Pigment Red 2, C.I. Pigment Red 3, C.I. Pigment Red 5, C.I. Pigment Red 6, C.I. Pigment Red 7, C.I. Pigment Red 15, C.I. Pigment Red 16, C.I. Pigment Red 17, C.I. Pigment Red 22, C.I. Pigment Red 23, C.I. Pigment Red 31, C.I. Pigment Red 38, C.I. Pigment Red 48:1, C.I. Pigment Red 48:2 (Permanent Red 2B(Ca)), C.I. Pigment Red 48:3, C.I. Pigment Red 48:4, C.I. Pigment Red 49:1, C.I. Pigment Red 52:2; C.I. Pigment Red 53:1, C.I. Pigment Red 57:1 (Brilliant Carmine 6B), C.I. Pigment Red 60:1, C.I. Pigment Red 63:1, C.I. Pigment Red 64:1, C.I. Pigment Red 81. C.I. Pigment Red 83, C.I. Pigment Red 88, C.I. Pigment Red 101(colcothar), C.I. Pigment Red 104, C.I. Pigment Red 106, C.I. Pigment Red 108 (Cadmium Red), C.I. Pigment Red 112, C.I. Pigment Red 114, C.I. Pigment Red 122 (Quinacridone Magenta), C.I. Pigment Red 123, C.I. Pigment Red 139, C.I. Pigment Red 44, C.I. Pigment Red 146, C.I. Pigment Red 149, C.I. Pigment Red 166, C.I. Pigment Red 168, C.I. Pigment Red 170, C.I. Pigment Red 172, C.I. Pigment Red 177, C.I. Pigment Red 178, C.I. Pigment Red 179, C.I. Pigment Red 185, C.I. Pigment Red 190, C.I. Pigment Red 193, C.I. Pigment Red 209, C.I. Pigment Red 219 and C.I. Pigment Red 222, C.I. Pigment Violet 1 (Rhodamine Lake), C.I. Pigment Violet 3, C.I. Pigment Violet 5:1, C.I. Pigment Violet 16, C.I. Pigment Violet 19, C.I. Pigment Violet 23 and C.I. Pigment Violet 38.
[0043] Examples of pigments for orange or yellow include: C.I. Pigment Yellow 1, C.I. Pigment Yellow 3, C.I. Pigment Yellow 12, C.I. Pigment Yellow 13, C.I. Pigment Yellow 14, C.I. Pigment Yellow 15, C.I. Pigment Yellow 15:3, C.I. Pigment Yellow 17, C.I. Pigment Yellow 24, C.I. Pigment Yellow 34, C.I. Pigment Yellow 35, C.I. Pigment Yellow 37, C.I. Pigment Yellow 42 (yellow iron oxides), C.I. Pigment Yellow 53, C.I. Pigment Yellow 55, C.I. Pigment Yellow 74, C.I. Pigment Yellow 81, C.I. Pigment Yellow 83, C.I. Pigment Yellow 93, C.I. Pigment Yellow 94, C.I. Pigment Yellow 95, C.I. Pigment Yellow 97, C.I. Pigment Yellow 98, C.I. Pigment Yellow 100, C.I. Pigment Yellow 101, C.I. Pigment Yellow 104, C.I. Pigment Yellow 408, C.I. Pigment Yellow 109, C.I. Pigment Yellow 110, C.I. Pigment Yellow 117, C.I. Pigment Yellow 120, C.I. Pigment Yellow 128, C.I. Pigment Yellow 138, C.I. Pigment Yellow 150, C.I. Pigment Yellow 151, C.I. Pigment Yellow 153 and C.I. Pigment Yellow 183; C.I. Pigment Orange 5, C.I. Pigment Orange 13, C.I. Pigment Orange 16, C.I. Pigment Orange 17, C.I. Pigment Orange 31, C.I. Pigment Orange 34, C.I. Pigment Orange 36, C.I. Pigment Orange 43, and C.I. Pigment Orange 51.
[0044] Examples of pigments for green or cyan include: C.I. Pigment Blue 1, C.I. Pigment Blue 2, C.I. Pigment Blue 15, C.I. Pigment Blue 15:1, C.I. Pigment Blue 15:2, C.I. Pigment Blue 15:3 (Phthalocyanine Blue), C.I. Pigment Blue 16, C.I. Pigment Blue 17:1, C.I. Pigment Blue 56, C.I. Pigment Blue 60, C.I. Pigment Blue 63, C.I. Pigment Green 1, C.I. Pigment Green 4, C.I. Pigment Green 7, C.I. Pigment Green 8, C.I. Pigment Green 10, C.I. Pigment Green 17, C.I. Pigment Green 18 and C.I. Pigment Green 36.
[0045] In addition to the above pigments, when red, green, blue or intermediate colors are required, it is preferable that the following pigments are employed individually or in combination thereof. Examples of employable pigments include: C.I. Pigment Red 209, 224, 177, and 194, C.I. Pigment Orange 43, C.I. Vat Violet 3, C.I. Pigment Violet 19, 23, and 37, C.I. Pigment Green 36, and 7, C.I. Pigment Blue 15:6.
[0046] Further, examples of pigments for black include: C.I. Pigment Black 1, C.I. Pigment Black 6, C.I. Pigment Black 7 and C.I. Pigment Black 11. Specific examples of pigments for black color ink usable in the present invention include carbon blacks (e.g., furnace black, lamp black, acetylene black, and channel black); (CI Pigment Black 7) or metal-based pigments (e.g., copper, iron (CI Pigment Black 11), and titanium oxide; and organic pigments (e.g., aniline black (CI Pigment Black 1).
[0047] The amount of the colorant contained in the inkjet ink, as a solid content, is preferably 0.5 weight % to 15 weight %, more preferably 0.8 weight % to 10 weight %, and even more preferably between 1 weight % and 6 weight %. When the amount of the water-insoluble pigment is less than 0.5 weight %, the color developing ability and image density of the ink may degrade. When it is more than 15 weight %, unfavorably, the viscosity of the ink is increased, which may cause degradation of ink ejection stability.
Cosolvent Fraction
[0048] The cosolvent fraction in accordance with the present invention is intended to stabilize the dispersed particles present, thus improving print head jet-reliability and for effectively preventing paper deformation. A cosolvent fraction capable of achieving the above comprises at least one branched polyhydric alcohol and/or at least one (poly)ether modified branched polyhydric alcohol.
[0049] Examples of suitable branched polyhydric alcohols are (but not limited to): trimethylol propane (TMP), trimethylol ethane (TME), pentaerithritol and neopentylglycol.
[0050] Examples of suitable (poly)ether modified branched polyhydric alcohols are (but are not limited to): trimethylol propane ethoxylate, trimethylol ethane ethoxylate, pentaerithritol ethoxylate, neopentylglycol ethoxylate, trimethylol propane propoxylate, trimethylol ethane propoxylate, pentaerithritol propoxylate, and neopentylglycol propoxylate.
[0051] For improving the print robustness while maintaining other properties, such as ink absorption, the number average molecular weight (M n ) of the (poly)ether modified polyhydric alcohol preferably does not exceed 1000 g/mol.
[0052] The molar mass of the (poly)ether modified polyhydric alcohol depends on the degree of substitution of the corresponding polyhydric alcohol and the (poly)ether chain length (see Formula 1):
[0000] Neopentyl glycol (Molar weight=104 g/mol): R 1 =R 2 =—H; R 3 =R 4 =—OH; maximum degree of substitution is 2;
Trimethylol ethane (Molar weight=120 g/mol): R 1 =—H; R 2 =R 3 =R 4 =—OH; maximum degree of substitution is 3;
Trimethylol propane (Molar weight=144 g/mol): R 1 =—CH 3 ; R 2 =R 3 =R 4 =—OH; maximum degree of substitution is 3
Pentaerithritol (Molar weight=136 g/mol): R 1 =R 2 =R 3 =R 4 =—OH; maximum degree of substitution is 4.
[0053] Commercially available (Sigma Aldrich) (poly)ether modified branched polyhydric alcohols are (but are not limited to): pentaerithritol ethoxylate having a molar mass of 270 g/mol and 797 g/mol respectively; trimethylol ethoxylate having a molar mass of 170 g/mol, 450 g/mol, 730 g/mol and 1014 g/mol, respectively; trimethylol propoxylate having a molar mass of 308 g/mol; pentaerithritol propoxylate having a molar mass of 426 g/mol and 624 g/mol respectively; and neopentyl glycol ethoxylate having a molar mass of 192 g/mol.
[0054] The average number of ethoxylate (p) or propoxylate groups (q+r) (see Formula 1) of the above disclosed (poly)ether modified branched polyhydric alcohols are given in Table 1.
[0055] Note that the length of individual (poly)ether chains (R 1 -R 4 in Formula 1) depends on the degree of substitution as described above. For example if the degree of substitution of pentaerithritol ethoxylate having a molar mass of 270 g/mol is 3, the length of each (poly)ether chain is 1.
[0000]
TABLE 1
average number of ethoxylate (p) or propoxylate groups (q +
r) of (poly)ether modified branched polyhydric alcohols.
Molar mass
p, q, r (Form. 1) 1
Pentaerithritol ethoxylate
270
p = 3, q = r = 0
797
p = 15, q = r = 0
Trimethylol ethoxylate
170
p = 0.6, q = r = 0
450
p = 7, q = r = 0
730
p = 13.3, q = r = 0
1014
p = 19.7, q = r = 0
Trimethylol propolylate
308
p = 0, q + r = 2.8
Pentaerithritol propoxylate
426
p = 0, q + r = 4.9
624
p = 0, q + r = 8.3
Neopentyl glycol ethoxylate
192
p = 2, q = r = 0
[0056] The cosolvent fraction may comprise one or more branched polyhydric alcohols and/or one or more (poly)ether modified branched polyhydric alcohol.
[0057] The cosolvent fraction may further comprise at least one linear polyhydric alcohol.
[0058] Examples of suitable linear polyhydric alcohols are (but not limited to): glycerin, 1,2,6-hexanetriol, diethylene glycol, triethylene glycol, tetra-ethylene glycol and dipropylene glycol.
[0059] The cosolvent fraction may comprise one or more linear polyhydric alcohols.
[0060] The total amount of the cosolvent fraction ranges from 10 weight % to 50 weight % relative to the total ink composition, preferably from 20 weight % to 45 weight %, more preferably from 30 weight % to 40 weight %.
Polyvinylpyrrolidone
[0061] The ink composition according to the present invention comprises a small amount (between 0.1 and 5 weight %) of high molecular (weight average molecular weight of at least 5000 g/mol) polyvinylpyrrolidone (PVP).
[0062] As a rule of thumb, it can be said that the higher the weight average molecular weight is, the lower the concentration in the ink composition needs to be to obtain the desired effect.
[0063] Commercially available PVP is PVP K25, a PVP having a weight average molecular weight (M w ) of 24000 g/mol, and PVP K15, a PVP having a weight average molecular weight (M w ) of 10000 g/mol, both of which can be obtained at Sigma Aldrich.
Other Additives
[0064] It is preferable that the ink of the present invention contains a surfactant in order to improve an ink ejection property and/or the wettability of the surface of a recording medium, and the image density and color saturation of the image formed and reducing white spots therein. To improve the spreading of the ink on the surface of recording medium and to reduce puddling, it is preferable to adjust the dynamic surface tension (measured at 10 Hz) of the ink composition to 35 mN/m or lower, preferably to 34 mN/m or lower, more preferably to 33 mN/m or lower, even more preferably to 32 mN/m or lower by the surfactant. The static surface tension of the ink composition is preferably below 30 mN/m (measured at 0.1 Hz). Examples of surfactants are not specifically limited and are well known in the art.
Receiving Media
[0065] Suitable receiving media for use in a printing process using an ink or set of inks (Cyan, Magenta, Yellow and blacK, CMYK) according to the present invention are not particularly limited to any type. The receiving medium may be suitably selected depending on the intended application.
[0066] Suitable receiving media may range from strongly water absorbing media such as plain paper (for example Océ Red Label) to non-water-absorbing media such as plastic sheets (for example PE, PP, PVC and PET films). To optimize print quality, inkjet coated media are known, which media comprise a highly water absorbing coating.
[0067] Of particular interest in the context of the present invention are Machine Coated (MC) media (also known as offset coated media) and glossy (coated) media. MC media are designed for use in conventional printing processes, for example offset printing and show good absorption characteristics with respect to solvents used in inks used in such printing processes, which are usually organic solvents. MC and glossy media show inferior absorption behavior with respect to water (worse than plain paper, better than plastic sheets), and hence aqueous inks.
Printing Process
[0068] A printing process in which the inks according to the present invention may be suitably used is described with reference to the appended drawings shown in FIG. 1 .
[0069] FIG. 1 shows that a sheet of a receiving medium, P, is transported in a direction for conveyance as indicated by arrows 50 and 51 and with the aid of transportation mechanism 12 . Transportation mechanism 12 may be a driven belt system comprising one (as shown in FIG. 1 ) or more belts. Alternatively, one or more of these belts may be exchanged for one or more drums. A transportation mechanism may be suitably configured depending on the requirements (e.g. sheet registration accuracy) of the sheet transportation in each step of the printing process and may hence comprise one or more driven belts and/or one or more drums. For a proper conveyance of the sheets of receiving medium, the sheets need to be fixed to the transportation mechanism. The way of fixation is not particularly limited and may be selected from electrostatic fixation, mechanical fixation (e.g. clamping) and vacuum fixation. Of these vacuum fixation is preferred.
[0070] The printing process as described below comprises the following steps: media pre-treatment, image formation and drying and fixing. Optionally the printing process comprises a post treatment step, which is not described here.
Media Pre-Treatment
[0071] To improve the spreading and pinning (i.e. fixation of pigments and water-dispersed polymer particles) of the ink on the receiving medium, in particular on slow absorbing media, such as machine coated media, the receiving medium may be pretreated, i.e. treated prior to printing an image on the medium. The pre-treatment step may comprise one or more of the following:
preheating of the receiving medium to enhance spreading of the used ink on the receiving medium and/or to enhance absorption of the used ink into the receiving medium; primer pre-treatment for increasing the surface tension of receiving medium in order to improve the wettability of the receiving medium by the used ink and to control the stability of the dispersed solid fraction of the ink composition (i.e. pigments and dispersed polymer particles). Primer pre-treatment may be performed by coating the receiving medium with a pre-treatment liquid. The pre-treatment liquid may comprise water as a solvent, one or more cosolvents, additives such as surfactants and at least one compound selected from a polyvalent metal salt, an acid and a cationic resin. As an application way of the pre-treatment liquid, any conventionally known methods can be used. Specific examples of an application way include: a roller coating, an ink-jet application, a curtain coating and a spray coating; corona or plasma treatment.
[0075] FIG. 1 shows that the sheet of receiving medium P may be conveyed to and passed through a first pre-treatment module 13 , which module may comprise a preheater, for example a radiation heater, a corona/plasma treatment unit, a gaseous acid treatment unit or a combination of any of the above. Optionally and subsequently, a predetermined quantity of the pre-treatment liquid is applied on the surface of the receiving medium P at pre-treatment liquid applying member 14 . Specifically, the pre-treatment liquid is provided from storage tank 15 of the pre-treatment liquid to the pre-treatment liquid applying member 14 composed of double rolls 16 and 17 . Each surface of the double rolls may be covered with a porous resin material such as sponge. After providing the pre-treatment liquid to auxiliary roll 16 first, the pre-treatment liquid is transferred to main roll 17 , and a predetermined quantity is applied on the surface of the receiving medium P. Subsequently, the receiving medium P on which the pre-treatment liquid was supplied may optionally be heated and dried by drying member 18 which is composed of a drying heater installed at the downstream position of the pre-treatment liquid applying member 14 in order to decrease the quantity of the water content in the pre-treatment liquid to a predetermined range. It is preferable to decrease the water content in an amount of 1.0 weight % to 30 weight % based on the total water content in the provided pre-treatment liquid provided on the receiving medium P.
Image Formation
[0076] Image formation is performed in such a manner that, employing an inkjet printer loaded with inkjet inks, ink droplets are ejected from the inkjet heads based on the digital signals onto a print medium.
[0077] Although both single pass inkjet printing and multi pass (i.e. scanning) inkjet printing may be used for image formation, single pass inkjet printing is preferably used since it is effective to perform high-speed printing. Single pass inkjet printing is an inkjet recording method with which ink droplets are deposited onto the receiving medium to form all pixels of the image by a single passage of a receiving medium underneath an inkjet marking module.
[0078] In FIG. 1, 11 represents an inkjet marking module comprising four inkjet marking devices, indicated with 111 , 112 , 113 and 114 , each arranged to eject an ink of a different color (e.g. Cyan, Magenta, Yellow and blacK). The nozzle pitch of each head is e.g. about 360 dpi. In the present invention, “dpi” indicates a dot number per 2.54 cm.
[0079] An inkjet marking device for use in single pass inkjet printing, 111 , 112 , 113 , 114 , has a length of at least the width of the desired printing range, indicated with double arrow 52 , the printing range being perpendicular to the media transport direction, indicated with arrows 50 and 51 . The inkjet marking device may comprise a single print head having a length of at least the width of said desired printing range. The inkjet marking device may also be constructed by combining two or more inkjet heads, such that the combined lengths of the individual inkjet heads cover the entire width of the printing range. Such a constructed inkjet marking device is also termed a page wide array (PWA) of print heads.
[0080] In image formation by ejecting an ink, an inkjet head (i.e. print head) employed may be either an on-demand type or a continuous type inkjet head. As an ink ejection system, there may be usable either the electric-mechanical conversion system (e.g., a single-cavity type, a double-cavity type, a bender type, a piston type, a shear mode type, or a shared wall type), or an electric-thermal conversion system (e.g., a thermal inkjet type, or a Bubble Jet type (registered trade name)). Among them, it is preferable to use a piezo type inkjet recording head which has nozzles of a diameter of 30 μm or less in the current image forming method.
[0081] FIG. 1 shows that after pre-treatment, the receiving medium P is conveyed to upstream part of the inkjet marking module 11 . Then, image formation is carried out by each color ink ejecting from each inkjet marking device 111 , 112 , 113 and 114 arranged so that the whole width of the receiving medium P is covered.
[0082] Optionally, the image formation may be carried out while the receiving medium is temperature controlled. For this purpose a temperature control device 19 may be arranged to control the temperature of the surface of the transportation mechanism (e.g. belt or drum) underneath the inkjet marking module 11 . The temperature control device 19 may be used to control the surface temperature of the receiving medium P, for example in the range of 30° C. to 60° C. The temperature control device 19 may comprise heaters, such as radiation heaters, and a cooling means, for example a cold blast, in order to control the surface temperature of the receiving medium within said range. Subsequently and while printing, the receiving medium P is conveyed to the down stream part of the inkjet marking module 11 .
Drying and Fixing
[0083] After an image has been formed on the receiving medium, the prints have to be dried and the image has to be fixed onto the receiving medium. Drying comprises the evaporation of solvents, in particular those solvents that have poor absorption characteristics with respect to the selected receiving medium.
[0084] FIG. 1 schematically shows a drying and fixing unit 20 , which may comprise a heater, for example a radiation heater. After an image has been formed, the print is conveyed to and passed through the drying and fixing unit 20 . The print is heated such that solvents present in the printed image, to a large extent water, evaporate. The speed of evaporation and hence drying may be enhanced by increasing the air refresh rate in the drying and fixing unit 20 . Simultaneously, film formation of the ink occurs, because the prints are heated to a temperature above the minimum film formation temperature (MFT). The residence time of the print in the drying and fixing unit 20 and the temperature at which the drying and fixing unit 20 operates are optimized, such that when the print leaves the drying and fixing unit 20 a dry and robust print has been obtained. As described above, the transportation mechanism 12 in the fixing and drying unit 20 may be separated from the transportation mechanism of the pre-treatment and printing section of the printing apparatus and may comprise a belt or a drum.
[0085] Hitherto, the printing process was described such that the image formation step was performed in-line with the pre-treatment step (e.g. application of an (aqueous) pre-treatment liquid) and a drying and fixing step, all performed by the same apparatus (see FIG. 1 ). However, the printing process is not restricted to the above-mentioned embodiment. A method in which two or more machines are connected through a belt conveyor, drum conveyor or a roller, and the step of applying a pre-treatment liquid, the (optional) step of drying a coating solution, the step of ejecting an inkjet ink to form an image and the step or drying an fixing the printed image are performed. It is, however, preferable to carry out image formation with the above defined in-line image forming method.
EXAMPLES
Materials
[0086] All chemicals were obtained from Sigma Aldrich and used as received, unless stated otherwise.
[0087] The receiving media used in the examples are Black Label 80 gsm (plain paper obtained from Océ), machine coated media TC+(Top Coated Plus Gloss obtained from Océ) and TCproS (Top Coated Pro Silk obtained from Océ).
Experimental and Measurement Methods
Surface Tension
[0088] The surface tension is measured using a Sita bubble pressure tensiometer, model SITA online t60, according to the (maximum) bubble pressure method. The surface tension of the liquids to be tested (e.g. inks according to the present invention) is measured at 30° C. unless otherwise indicated. The static surface tension is determined at a frequency of 0.1 Hz. The dynamic surface tension is determined at a frequency of 10 Hz.
Viscosity
[0089] The viscosity is measured using a Haake Rheometer, type Haake Rheostress RS 600, with a flat plate geometry at a temperature of 32° C. unless otherwise indicated. The viscosity is measured at shear rates ({dot over (γ)}) in the range of between 10 s −1 and 1000 s −1 , unless otherwise indicated.
Fusing Experiments
[0090] Fusing experiments are performed with a Ricoh Fuser, model 592 of Ricoh Company LTD. The Ricoh fuser comprises a rotatable drum (fuse drum) having a diameter of 20 cm and a page-wide Halogen fuse lamp having a power of approximately 750 W. The fuse lamp is arranged at a position opposite to the fuse drum at a distance of 3 cm. The Ricoh fuser can be operated at settings from 1 to 10. Each setting corresponding to a rotation speed of the fuse drum: e.g. settings 4 and 6 correspond to fuse drum rotational speeds of 20 RPM and 35 RPM respectively.
[0091] The rotation speed of the fuse drum increases with an increasing Ricoh fuse setting. The exposure time to fuse radiation of a sheet of recording medium transported by the fuse drum decreases with an increasing Ricoh fuse setting, hence the applied fuse energy decreases with increasing Ricoh fuse setting. All fusing experiments performed with inks according to the present invention were performed under the same conditions.
Robustness
[0092] Directly after fusing an ink image to a sheet of recording media, the ink layer is rubbed with a teat for Pasteur pipettes made of PVC (Volac Red Teat, art. Number D813 obtained from Poulten & Graf Ltd). The robustness of the print is (visually) judged based on the damage imparted to the ink layer and valued from 0 to 10, wherein:
[0000] 10 represents an excellent print robustness: no damage imparted to the ink layer;
7-9 represents a good print robustness: some matting effect of the rubbed area;
4-6 represents a sufficient print robustness: minor visual damage imparted to the ink layer;
1-3 represents a weak print robustness: substantial visual damage imparted to the ink layer;
0 represents a bad print robustness: completely removed ink layer after rubbing.
Preparation of Ink Compositions
Comparative Example A
[0093] 85 grams of NeoCryl A-662 latex (obtained from DSM, 40 weight % latex, the latex particles having an average particle diameter D50 of ±100 nm; the latex resin having a T g of 97° C. and a MFFT>90° C.), 82.5 grams of Neocryl XK237 latex (obtained from DSM, 40 weight % latex, the latex resin having an MFFT 8° C.), 271.4 grams of Pro-Jet Cyan APD 1000 pigment dispersion (14 weight % pigment dispersion, obtained from FujiFilm Imaging Colorants), 123 grams of glycerol (obtained from Sigma Aldrich), 154 grams of trimethylolpropane (obtained from Sigma Aldrich), 17 grams of a surfactant mix comprising Tegowet 240 (obtained from Evonik industries), Dynol 607 (obtained from Air Products) and BYK 348 (obtained from BYK), wherein the mass ratio of Tegowet 240: Dynol 607: BYK 348 was 1:2.5:1. and 267.1 grams of demineralized water were mixed in a vessel, stirred for approximately 60 minutes and filtered over a Pall Profile Star absolute glass filter having a pore size of 1 μm. The obtained ink composition is shown in Table 2.
Example 1
[0094] The procedure of comparative example A was repeated and 4 grams of polyvinylpyrrolidone having a molecular weight of approximately 24.000 grams/mol (PVP K25 obtained from Sigma Aldrich) was added. The amounts of the constituents were slightly modified to obtain an ink composition having a viscosity similar to the ink composition according to comparative example A. The obtained ink composition is shown in Table 2.
Example 2
[0095] The procedure of example 1 was repeated, wherein PVP K25 was replaced by 8 grams of PVP K15 (polyvinylpyrrolidone obtained from Sigma Aldrich and having a molecular weight of approximately 10.000 grams/mol). The amounts of the constituents were slightly modified to obtain an ink composition having a viscosity similar to the ink composition according to comparative example A and example 1. The obtained ink composition is shown in Table 2.
Comparative Example B
[0096] The procedure of comparative example A was repeated, wherein TMP was replaced by 154 grams of pentaerythritol ethoxylate (¾ EO/OH, i.e. 3 out of 4 —OH groups of pentaerythritol have been (poly)ether modified) obtained from Sigma Aldrich. The amounts of the constituents were slightly modified to obtain an ink composition having a viscosity similar to the ink composition according to the other examples. The obtained ink composition is shown in Table 2.
Example 3
[0097] The procedure of comparative example B was repeated and 4 grams of polyvinylpyrrolidone having a molecular weight of approximately 24.000 grams/mol (PVP K25 obtained from Sigma Aldrich) was added. The amounts of the constituents were slightly modified to obtain an ink composition having a viscosity similar to the ink composition according to comparative example B. The obtained ink composition is shown in Table 2.
Robustness Experiments
Example 4
[0098] The inks according to comparative examples A and B and examples 1-3 were applied to the above described print substrates, by rod coating an ink layer having a thickness of 8 μm. The wet rod coat samples were subjected to the Ricoh fuser as described above and treated at a fuse setting 6 corresponding to fuse drum rotational speed of 35 RPM.
[0099] The robustness of the thus treated prints was determined in accordance with the above described method. The results are shown in Table 3.
[0000]
TABLE 2
Ink compositions of comparative examples A and
B and examples 1-3. The amounts are in weight
% relative to the total ink composition.
(comparative) examples:
compound
A
1
2
B
3
Latex 1)
A-662 2)
3.4
2.8
2.9
3.2
2.8
XK237 2)
3.3
2.8
2.9
3.2
2.8
Pigment 1)3)
3.8
3.9
3.8
3.8
3.9
Cosolvents
glycerol
12.3
12.8
12.7
12.4
12.6
TMP 4)
15.4
15.7
16
—
—
Penta 5)
—
—
—
15.4
15.9
Additive
PVP K25 6)
—
0.4
—
—
0.4
PVP K15 6)
—
—
0.8
—
—
Surfactant mix 7)
1.7
1.7
1.7
1.6
1.7
Balance water
to 100%
properties
Viscosity @ 32° C.
5
5.2
5.3
4.9
4.9
[mPa · s]
Surface tension @ 25° C.,
24-32.5
24-32.5
24-32.5
n.d.
n.d.
0.1-10 Hz [mN/m]
1) The amount of latex and pigment is the amount of solids relative to the total ink composition
2) DSM Neocryl series
3) Pro-jet Cyan APD 1000 pigment (FujiFilm Imaging Colorants)
4) Trimethylolpropane
5) Pentaerythritol ethoxylate (3/4 EO/OH), having molar mass of 270 g/mol
6) Polyvinylpyrrolidone (K25: M w ≈24000 g/mol; K15: M w ≈10000 g/mol)
7) Surfactant mix comprises Tegowet 240:Dynol 607:Byk 348 in a 1:2.5:1 ratio
[0000]
TABLE 3
Results robustness tests
Comp.
Comp.
Ex. A
Ex. 1
Ex. 2
Ex. B
Ex. 3
Black Label
6
7
7
5
7
TC + gloss
2
8
7
2
7
TCProS
3
7
7
4
7
[0100] Table 3 shows that by adding PVP to ink compositions comprising a branched polyhydric alcohol (TMP in comparative example A) or a (poly)ether modified branched polyhydric alcohol (Penta in comparative example B), the robustness of ink layers prepared under similar conditions improves significantly (compare examples 1 and 2 with comparative example A and example 3 with comparative example B).
[0101] Table 3 further shows that by using PVP having a lower molecular weight in a larger concentration in the ink composition (compare example 2 with example 1), results in a similar robustness of ink layers prepared under similar conditions. It may therefore be concluded that the molecular mass of the used PVP and its concentration in the ink composition are exchangeable parameters for designing inks also comprising a branched polyhydric alcohol or a (poly)ether modified branched polyhydric alcohol and having improved robustness characteristics.
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An ink composition includes a dispersion of resin particles in water, a colorant and a co-solvent fraction for stabilizing the dispersion, wherein the co-solvent fraction includes at least one branched polyhydric alcohol and/or at least one (poly)ether modified branched polyhydric alcohol, and between 0.1 and 5 weight % polyvinylpyrrolidone having a weight average molecular weight of at least 5000 g/mol. Such ink compositions show improved robustness on a range of print substrates. In this way robust look and feel films can be realized also on less absorbing media, like the offset coated gloss, silk and matt ones with a better freedom towards recipe variation of e.g. latex and the concentrations of the ingredients.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to application of mortar between the vertical walls of adjacent building block elements, more specifically to a tool for experienced and inexperienced workers to accurately, repeatedly, place the correct amount of mortaring cement between facing sides of adjacent blocks in construction of a wall. With the tool, blocks can be placed in a horizontal line accurately, eliminating the need to set blocks vertically and horizontally at the same time. It can be used to horizontally fill the space where a wall abuts a header, and also against an adjacent wall.
2. Description of the Prior Art
The prior art is replete with patented apparatus for applying mortar to a course of adjacent building block elements.
U.S. Pat. No. 3,764,222 patented Oct. 9, 1973 by Orthman describes a box having a bottom opening that is about as wide as a brick. A pair of guide rails on the bottom of the box are designed to guide the box for lengthwise movement along the top of a wall. A slide-out plate seals the bottom of the box. The box is filled with mortar and the plate is slid out so that the mortar is deposited on and between adjacent bricks as the box is pulled along the wall. The trailing end of the box has a liftable gate which can be set at a desired height above the bricks to control the thickness of the layer of mortar that is left behind on the top of the bricks as the box is pulled forward. Alignment members extend downward from the sides of the box so that they hug the side of the wall being built to align the box vertically and scrape the mortar overflowing to the side of the wall.
U.S. Pat. No. 3,999,920 patented Dec. 28, 1976 by Cerillo, Jr., describes a container that is positioned over the space between two adjacent bricks in a course of bricks such as on the top of a wall under construction. In the bottom of the container, positioned over the opening, is a slot that is wider than, and almost as long as, the opening between the bricks. The slot is temporarily sealed by a slide gate. Vertical bars extending downward from opposite sides of the box seal the vertical open ends of the space between the bricks. The gate is open allowing the mortar to enter the space between the bricks until the space is filled, then the gate is closed. The container is then lifted straight up from the filled space between the bricks and slid down over another empty space between bricks of the course, aligned with the space by the vertical bars which each present a convex surface toward the opening.
U.S. Pat. No. 4,311,258 patented Jan. 19, 1982 by P. Bradshaw describes a cylindrical barrel having at the front end of the barrel, a cap formed into a tubular stalk outlet cut on a bias. A plunger sealingly slides within the tube, operated by a ratchet trigger mechanism to force mortar from within the tube, out of the tube through the stalk. The tube is refilled by removing the cap and drawing the mortar into the tube by pulling the plunger in the tube toward the back end of the tube.
U.S. Pat. No. 5,114,040 patented May 19, 1992 by Brenish et al. describes a hopper having horizontally elongated, angled downward and inward, side walls which terminate in a longitudinal slot opening at the bottom of the hopper. A pair of parallel guide strips, open downward and at their ends, extend downward from the slot the length of the slot. The hopper is supported a fixed height by skids on spaced adjacent paving stones so that the guide strips extend into the space between the stones. A plunger consisting of a horizontal bar having sides of the lower half of the bar angled downward and inward at the same angle as the side walls, terminating in a flat bottom, and the sides of the upper half angled upward and inward, is held in the hopper parallel to the slot by a vertical handle, and reciprocated up and down in the cement filled hopper so that the cement is mixed and dispensed through the slot. When the bar comes in contact with the side walls of the hopper it seals the opening, and the hopper can be moved further along the space between the paving stones.
U.S. Pat. No. 5,695,560 patented Dec. 9, 1997 by R. Hession describes a hopper having two parallel exit slots, spaced apart so that each slot lays a ribbon of mortar along one edge of the top of a row of bricks as the hopper rolls along the top of the row of bricks supported by plurality of wheels riding on the bricks between the slots, and guided laterally by outboard vertically axled wheels bearing on the opposite sides of the bricks below the top of the bricks.
U.S. Pat. No. 5,996,856, patented by J. Duncan on Dec. 7, 1999 describes a container that contains a worm gear driven by an electric motor to force mortar in the container from the container into a tube having a clamp and a tube spreader assembly mounted on the end of the tube. The container is mounted on an arm that is mounted on a track follower assembly.
SUMMARY OF THE INVENTION
It is one object of the invention to provide a hand tool for applying masonry binder or filler material between adjacent masonry units in a masonry construction. It is another object of the invention that the tool extends into the space between the adjacent masonry units to the surface upon which the masonry units rest. It is another object that the binder material is added to the space as the tool is moved out of the space away from the surface upon which the masonry units rest. Other objects and advantages will become apparent to one reading the ensuing description of the invention.
A container includes a flexible tube that is elongated in cross section. The tube is at least as long as a first length of a first facing surface of adjacent, facing, spaced apart surfaces of adjacent masonry units. An opening in the tube is shorter in the elongated direction than a second length of the first facing surface normal to the first length of the first facing surface.
Another tool of the invention for inserting mortar between a first surface having a height and a width of a first masonry unit, and a second surface of a second masonry unit adjacent to, facing and spaced from the first surface, includes a container that includes a flexible elongated in cross section tube, a first opening at a first end of the tube being shorter in the elongated direction than the width of the first face unit and spaced from a shoulder on said tool a distance no longer than the height of the first masonry unit, and a second opening in the container configured for receiving mortar for passing mortar through said tube to the first opening.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention be more fully comprehended, it will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of adjacent brick masonry units.
FIG. 2 is a perspective view of a delivery element of the invention.
FIG. 3 is a cross section view of the delivery element of FIG. 2 taken along 3 — 3 , in the space between the bricks of FIG. 1, resting on a layer of mortar on another brick of a wall.
FIG. 4 is a cross section view of the delivery element of FIG. 2 taken along 4 — 4 in the space between the bricks of FIG. 1, resting on a layer of mortar on another brick of a wall as in FIG. 3 .
FIG. 5 is a perspective view of a hand piston of the invention.
FIG. 6 is a cross section view of the piston of FIG. 5 taken along 6 — 6 .
FIG. 7 is a cross section view of the piston of FIG. 5 taken along 7 — 7 .
FIG. 8 is another piston of the invention.
FIG. 9 is a cross section view of the piston of FIG. 8 taken along 9 — 9 .
FIG. 10 is a schematic view of another delivery element of the invention.
FIG. 11 is a schematic view of another delivery element of the invention in a space between bricks, resting on a layer of mortar on another brick of a wall.
FIG. 12 is a schematic view of another delivery element of the invention in a space A between bricks, being moved away from a layer of mortar on another brick of a wall.
FIG. 13 is a schematic view of another delivery element of the invention being filled with a trowel as the delivery element is in contact with a layer of cement on the top of a wall
FIG. 14 is a perspective view of another delivery element of the invention receiving a trowel.
FIG. 15 is a perspective view of the tube of a delivery element positioned for moving between facing surfaces of adjacent paving stone masonry units.
FIG. 16 is a view of the piston of FIG. 8 and a flexible tube.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining the invention in detail, it is to be understood that the invention is not limited in its application to the detail of construction and arrangement of parts illustrated in the drawings since the invention is capable of other embodiments and of being practiced or carried out in various ways. It is also to be understood that the phraseology or terminology employed is for the purpose of description only and not of limitation.
The term “mortar” used herein in the specification and in the claims is herein defined to mean masonry binder material or mansonary filler material, which includes but is not limited to mortar and cement.
Referring to FIGS. 1-7, flexible oval tube 20 of delivery element 28 is attached to radially extending shoulder 30 . Preferably the shoulder is molded as one with the tube.
Tube 20 may be made about as long 60 as the length 62 of space 36 . Length 62 is the same as, and parallels the width of brick 40 . Tube 20 may be made as high 64 as space 36 , and element 28 can be inserted to the bottom of the space to the surface upon which bricks 40 , 42 rest and then gradually drawn up as the mortar is forced out of the tube by gravity or by piston 50 .
The tube is inserted, preferably from the top, into vertical slot space 36 between bricks 40 , 42 at about centerline 46 . Shoulder 30 rests on tops 84 , 86 of the bricks.
A sufficient amount of mortar is loaded into the tube by way of opening 38 preferably to fill to the top 86 at least one of bricks 40 , 42 . FIGS. 13 and 14 show delivery elements of the invention being filled by a trowel. Other filler tools can be used.
The tube is raised or lifted up to allow the mortar to exit the tube by way of opening 52 .
The bricks can be left in their just filled position. This fills slot space 36 completely across the facing surfaces 41 , 43 of the bricks.
Less mortar can be loaded into the tube, and the bricks are then pushed together after the tube is raised from the space between the bricks, but can be pushed together while the tube is being raised. They can be pushed together 58 to move the mortar evenly over each of the adjacent brick surfaces.
A piston may be used. Hand piston 50 oval end 54 closely fits opening 38 . The piston is pushed down by handle 53 into the tube so that the piston forces the measured amount of mortar into the vertical slot space. Enlarged tip 56 keeps the hand form slipping off the handle when the piston is withdrawn from the tube.
In FIGS. 8, 9 , and 16 , hand piston paddle section 68 of piston 66 is used to push mortar into a narrow space such as a horizontal space between a top building block and a ceiling. The paddle is operated by handle 72 . Piston 66 is molded in one piece of a flexible plastic. The flexible tube 76 containing the piston and conforming to the shape of the piston can be inserted into the space next to a ceiling or wall by a hand on handle 72 without the wall interfering with the hand, by flexing the handle portion of the piston away from the wall.
In FIG. 10, delivery element 70 is held by ring 74 as flexible tube 78 is inserted onto vertical slot space 36 until shoulder 82 rests on tops 84 , 86 of bricks 40 , 42 . Then mortar is delivered into the space by the tube as piston 50 is pushed down through openings 92 , 96 and tube 78 .
The invention can also be used to deliver mortar horizontally into vertical slot space 36 by laying tube 78 sideways in opening 36 and drawing the delivery element out sideways as the mortar is delivered into the space as the piston is pushed through openings 92 , 96 and tube 78 .
In FIG. 11, delivery element 104 is resting on mortar 106 that is on top of row 108 of bricks 110 , and in the space 114 between cap stones 118 and 120 .
In FIG. 12, delivery element 124 which has been filled up through enlarged portion 138 with a quantity of mortar 156 is in space 130 between cap stones 126 , 128 . Element 124 is being removed 134 from layer 144 of mortar 154 that is on top row 148 of wall stones 150 . As delivery element 124 is removed, mortar 156 exits tube 160 at opening 164 . Tube 160 of delivery element 124 is stiff. Stones 150 are either left permanently with space 130 filled with mortar, or they may be moved closer together after tube 160 is moved out of the space.
In FIG. 13, delivery element 170 is held by movable and removable handle 174 as mortar is loaded into large upper portion 178 by tool 186 . The mortar moves by gravity into flexible tube 192 . Portion 188 of tube 192 that is between bricks 212 , 214 , is pinched to a smaller diameter than the upper portion of tube 192 of the tube as the bricks moved closer together after the tube is inserted 196 between the bricks. When the tube is lifted 200 from the space between the bricks, the tube leaves mortar in the space between the bricks. Delivery element 170 can be supplied with tube 192 of a larger length than either the height or width of standard bricks or of cap stones. The tube is cut in the field to suit the height or width of the space to be encountered and the direction at which the tube is to be inserted into and withdrawn from the space.
In FIG. 14 element 216 is receiving spade 218 .
In FIG. 15 flexible tube 220 of a delivery unit of the invention is positioned for insertion 224 between adjacent facing surfaces 226 , 228 of paving stone masonry units 232 , 234 .
Although the present invention has been described with respect to details of certain embodiments thereof, it is not intended that such details be limitations upon the scope of the invention. It will be obvious to those skilled in the art that various modifications and substitutions may be made without departing from the spirit and scope of the invention as set forth in the following claims.
Drawing Designators (Informal List)
20 flexible tube
28 delivery element
30 shoulder
36 vertical slot space
38 opening
40 brick
41 facing surface
42 brick
43 facing surface
46 centerline
F 50 piston, hand
52 opening
53 handle
54 oval end
56 enlarged tip
58 direction arrow, pushed together
60 length, arrow
62 length of space 36
64 height, arrow
66 piston
68 section of piston 66
70 delivery element
72 handle
74 ring
76 flexible tube
78 tube
82 shoulder
84 top of brick
86 top of brick
92 opening
96 opening
104 delivery element
106 mortar
108 top row
110 brick
114 space
118 cap stone
120 cap stone
124 delivery element
126 cap stone
128 cap stone
130 space
134 removed, direction arrow
138 enlarged portion
144 layer of mortar
148 top row
150 wall stone
154 mortar
156 mortar
160 tube
170 delivery element
174 handle
178 larger upper portion
186 tool
188 portion of tube 190
192 tube, flexible
196 inserted, direction arrow
200 lifted, direction arrow
212 brick
214 brick
216 delivery element
218 spade
220 flexible tube
224 insertion, direction arrow
226 facing surface
228 facing surface
232 paving stone
234 paving stone
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A container that is filled from one end with mortar includes a flexible tube at the other end that is elongated in cross section and open at one end. A shoulder on the container is spaced from the opening about the distance of the height of an opening between facing surfaces of adjacent masonry units that is to be filled with the mortar.
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BACKGROUND OR THE INVENTION
(1) Field of the Invention
This invention relates to material for non-magnetic substrates used for sliders of the magnetic heads.
(2) Description of the Prior Art
Magnetic heads used for magnetic disks ordinarily have a structure as disclosed, for example, in Japanese Patent Publication No. 57-569. In these floating type magnetic heads, a magnetic core made from a magnetic material of high permeability is fixed to the rear end portions of sliders each comprising a magnetic or non-magnetic substrate. On the lower sides of the sliders, the magnetic core has a gap for magnetic transduction. The magnetic core further has a winding for electromagnetic transduction, whereby a magnetic transducer is formed. A floating type magnetic head having such a structure is in light contact with a magnetic disk due to a spring action when the magnetic disk is stopped. When the magnetic disk is rotating, the air around the surface of the magnetic disk also moves pushing up the lower sides of magnetic head sliders.
The transducer portion of magnetic head is made, in many cases, from a soft ferrite such as Mn-Zn ferrite or Ni-Zn ferrite. When the recording density of magnetic disk is increased, it is required that the width of magnetic core and the length of the gap for magnetic transduction be made smaller, and at that time, the magnetic core is made from a magnetic thin film of permalloy or amorphous metal made by sputtering, etc. There are cases that one magnetic core is made from a soft ferrite and the other core from a magnetic thin film. When a thin film core is used a thin film of insulating material such as Al 2 O 3 may be applied on both the thin film magnetic core and sliders to obtain electrical insulation between a winding for the electromagnetic transduction and the thin film core or between coils for electromagnetic transduction. When non-magnetic slider substrates are made from a material of relatively low electrical resistance a thin film of insulating material may be applied on the sliders to obtain insulation between the sliders and the magnetic thin film core to form a magnetic transducer.
Such a magnetic head does not contact the magnetic disk when the magnetic disk is rotating because the head is buoyant due to the flow of air. The magnetic head, however, comes in contact with the magnetic disk when the magnetic disk starts or stops rotation. For example, when the magnetic disk stops rotation, the magnetic head comes in contact with the magnetic disk as follows. As the magnetic disk reduces its rotation speed, the flow speed of the air around the surface of the magnetic disk becomes slow. When buoyancy for the magnetic head is lost, the magnetic head hits the magnetic disk. As a reaction, the magnetic head jumps up and drops on the disk again. Such a movement is repeated many times (the magnetic head appears to be dragged on the magnetic disk) and there comes a final stop. Any magnetic head must be able to withstand a shock at the start or stop of the magnetic disk and such an ability of a magnetic head at such times is called its CSS resistance (CSS stands for contact-start-stop).
In order for a magnetic head to have a superior CSS resistance property, the slider portion of the magnetic head must have excellent slidability. Further, the slider portion must be flat and free from pores and have good wear resistance.
The slider portion of magnetic head has a very complex structure as shown, for example, in Japanese Patent Laid-open No. 55-163665. In order to produce a slider of such a structure at a high productivity, the material for slider must have good machinability. Further, it is desirable that chipping of the slider material during machining be as little as possible. For this purpose, it is desirable that the slider material have crystal grain particles as small as possible.
Such a magnetic head as described above its disclosed in Japanese Patent Laid-open No. 55-163665 mentioned above. The slider of this magnetic head is made from a mixture of Al 2 O 3 and TiC and the weight ratio of Al 2 O 3 to TiC is in a range of 60:40 to 80:20. Al 2 O 3 -TiC ceramics have some disadvantages for example, the low density and tendency of chipping because of low affinity between Al 2 O 3 and TiC particles. When chipped, the chips are large because of the large grain size of 4 to 5 μm.
SUMMARY OF THE INVENTION
This invention is to provide a ceramic substrate for thin film magnetic head which is hard to chip by making the relative density more than 99% through reinforcement of the bonding strength and also by making the average crystal particle diameter of about 1 μm or smaller. The ceramic substrate of this invention improves the resistance to CSS by increasing the bonding strength as aforementioned.
The ceramic substrate of this invention contains 20-55 weight % of titanium carbide as its main component, the remaining substantially consisting of aluminum oxide, and contains total 0.05-5 weight parts of silicon oxide or iron oxide to 100 weight parts of the major ceramic components.
The ceramic substrate of this invention can further contain a total of 0.05-5 weight parts of chromium oxide and/or tungsten oxide as an additive.
The titanium carbide 5-60 mol% in the major ceramic component can be substituted by carbide of zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum or tungsten or oxide of titanium, zirconium, hafnium, vanadium, niobium or tantalum. Further, 5-60 mol% of the aluminum oxide may be substituted by zirconium oxide. It is desirable to make the crystal structure of zirconium oxide tetragonal by forming a solid solution of magnesium oxide, calcium oxide or yttrium oxide of 2-10 mol% in the zirconium oxide.
DESCRIPTION OF PREFERRED EMBODIMENTS
In order to produce the ceramic substrate for the thin film magnetic head, the mixed form of aluminum oxide powder, titanium carbide powder and any additives is sintered in vacuum or inert gas, hot pressed or hot isostatically pressed (HIP). According to this invention, by adding silicon and/or iron oxide to the main ceramic component, the interfacial strength between the aluminum oxide particles and titanium carbide particles is increased. In the course of sintering, the silicon oxide and iron oxide react with titanium carbide or carbon of the graphite crucible to become silicon carbide and subsequently react again with the oxygen of the aluminium oxide to become silicon oxide and iron oxide, and it is considered that this repeated process activates the surface of the titanium carbide and aluminium oxide particles, thus achieving the strong bonding. Furthermore, by adding one or two of chromium and tungsten oxides together with the silicon and iron oxides, the bonding between the aluminium oxide and titanium carbide particles could be made stronger.
If the sum amount of the silicon and iron oxides is less than 0.05 weight parts in total, the addition is not effective, and if it is more than 5 weight parts, the hardness decreases, and therefore, the amount of these oxides is preferable to be the 0.05-5.0 weight parts.
If the total amount of the chromium and tungsten oxides is less than 0.05 weight parts, there is no effect of increasing the bonding strength of Al 2 O 3 and TiC, and if it is more than 5 weight parts, the hardness decreases, and therefore, the amount of these oxides should be 0.05-5.0 weight parts.
Also, by substituting the titanium carbide of the above composition with one or more types of Zr, Hf, V, Nb, Ta, Cr, Mo, or W carbide and furthermore, with one or more types of Ti, Zr, Hf, V, Nb or Ta nitride, the sintered structure of the above composition will have micron-sized grains. These additives are not effective at less than 5 mol% of titanium carbide, and if they are more than 60 mol%, the sintering property deteriorates, and therefore, the appropriate amount is 5-60 mol%. Also, by substituting the aluminium oxide of the above composition with zirconium oxide, the aluminium oxide phase is strengthened and the resistance to chipping is improved. Especially it is effective if 2-10 mol% of one or more types of MgO, CaO and Y 2 O 3 are dissolved in a solid solution as a stabilizer for the zirconium oxide.
The zirconium oxide does not contribute to the toughness if its added amount is less than 5 mol%, and at more than 60 mol%, the hardness is considerably decreased, and therefore, the amount of zirconium oxide is desirable to be 5-60 mol%. The amount of Y 2 O 3 , CaO and MgO is limited to 2-10 mol% because at less than 2 mol%, they are not effective for the residue of the tetragonal zirconia (residue until room temperature) which increases the toughness of ZrO 2 and at more than 10 mol%, the cubic phase appears to reduce the strength.
The ceramic substrate of this invention can be manufactured by the Hot press method and HIP (hot Isostatic Press) method which is used after the relative density was made more than 94% by sintering in a gas atmosphere furnace. But the most desirable method is to sinter to achieve the relative density of more than 98% by means of the hot press and then to increase the relative density to almost 100% by means of the hot isostatic press.
The ceramic substrate of this invention has a superior resistance to CSS because its relative density is very high at more than 99%, no pores of more than 1 μm nor chipping is detected and the hardness Hv is more than 2000 when measured with the load of 200 g.
EXAMPLE 1
To the aluminum oxide of purity 99.9% and average particle diameter 0.5 μm and titanium carbide of purity 99.5% and average particle diameter 0.6 μm, silicon, iron, chromium and tungsten oxide powder, 1st grade reagent, were added at the ratios shown in Table 1 and they were mixed for 24 hours with a ball mill. After drying, they were granulated and formed into the dimensions of 80 mm dia.×7-8 mm high under the pressure of 1 t/cm 2 .
The form was set in a graphite mold and treated at 1600° C. for 1 hour in vacuum. Subsequently it was further treated at 1500° C., 1500 atmospheric pressure and in an argon atmosphere for 1 hour. The sintered form was machined into the size of 76.2 mm dia.×4 mm thick and then the one side was lapped to 0.01S (roughness less than 0.01 μm). The lapped surface was observed for pores by using a microscope and the size of the pores were measured. The relative density was calculated on basis of the size of the holes and their distribution. The sintered form was cut with a diamond blade and the dimensions of chipping caused at the edge between the lapped surface and the cut surface were measured.
Furthermore, the fractured surface was observed through a scanning type electronic microscope and the diameter of the crystal grains was measured. The results of the above measurements are shown in Table 1.
Nos. 1, 2, 3, 4, 6, 9, 13, and 16 in Table 1 are comparison examples.
No. 1 is a conventional hot-pressed product of Al 2 O 3 -TiC, and its relative density is low at 98.5%, many pores of larger than 1 μm can be found on the lapped surface, and chipping is of more than 1 μm. Nos. 2 and 3 are the products whose density was increased by adding MgO and NiO, but still the pores and chipping are large. On the other hand, the ceramics of this invention with the additives of SiO 2 and Fe 2 O 3 were considerably improved in terms of pores and chipping. When only SiO 2 is added, No. 4 with small amount still has large pores and chippings, but in the case of No. 5 with 1% silicon oxide the relative density becomes more than 99.7% and the pores and chipping of larger than 1 μm disappear. No. 6 with 8% silicon oxide has fewer pores and chippings, but its Vickers hardness is low at 1700 while the other products have more than 2000, and therefore, it is not suited for the head substrate. In the case of Fe 2 O 3 , too, the addition of 0.05-5% improved the hardness, pores and chipping altogether.
Nos. 11-18 show the cases where Cr 2 O 3 and/or WO 3 were added in addition to the SiO 2 and Fe 2 O 3 , and still the hardness is reduced in the case of Nos. 13 and 16 which have too much addition. In case the Cr 2 O 3 and/or WO 3 were more added in comparison with the additives SiO 2 and Fe 2 O 3 , no chipping was found because the bonding strength between Al 2 O 3 and TiC was further increased.
EXAMPLE 2
In addition to the mixed composition of the Example 1, samples were prepared in the same method as for the Example 1 by mixing the carbides and nitrides of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W, and evaluated as shown in Table 2.
Nos. 1, 3, 5 and 7 in Table 2 are comparison examples.
No. 1 is a conventional hot-pressed product and its relative density is low and its particle diameter is large. If SiO 2 and Fe 2 O 3 are added to it, the relative density increases but the particle diameter is still large. Nos. 3-5 are the cases where TiC was partially substituted by ZrC, but if the substituted amount is small at 4 mol%, the particle diameter is still large, 3-4 μm. On the other hand, if the substituted amount is large, like No. 4 22.5 mol% and No. 5 74.4%, the particle diameter becomes smaller than 1 μm and the effect of ZrC substitution on micronizing the crystal particles is remarkable. But if the substituted amount is too large as in the case of No. 5, even if SiO 2 and Fe 2 O 3 are added, the density is reduced and therefore, it is not suitable for the substrate. In the case of No. 7, too, the crystal particles are made fine through the ZrC substitution, but because the SiO 2 and Fe 2 O 3 are not added, the density is low.
Nos. 6 and 8-16 are the cases where SiO 2 , Fe 2 O 3 , Cr 2 O 3 , and/or WO 3 are added and part of TiC is substituted by the nitride and carbide, and in every case, the crystal particles are of smaller than 1 μm, the relative density is high at 99.7% and no chipping and holes of more than 1 μm were found.
EXAMPLE 3
Samples were manufactured in the same method as for the Example 1 by mixing zirconium oxide and its stabilizer and the breaking strength was measured by JIS (Japanese Institute of Standards) 4-point bending test method and the relative density, etc. were also measured. The results are shown in Table 3.
Nos. 1, 2, 6 and 8 in Table 3 are comparison examples.
No. 1 is a conventional hot-pressed product and the breaking strength is low at 50 kg/cm 2 . For No. 2 with 10% of ZrO 2 added, the breaking strength slightly increases, but is still low. No. 3 is a product of this invention with the additives of SiO 2 and Fe 2 O 3 , but the strength is still low at 50 kg/m 2 . Nos. 4 to 10 are the cases where the amount of ZrO 2 and Y 2 O 3 was changed. In every case of Nos. 4, 5, 9 and 10 where ZrO 2 10% was added and the amount of Y 2 O 3 was changed to be 0, 1, 3 and 12 mol% in ZrO 2 , the breaking strength is increased in comparison with the cases where ZrO 2 was not added. But at 0 and 1 mol%, it is not so much increased (up to 60 kg/m 2 ). On the other hand, at 3 mol%, it increased to 73 kg/m 2 and at 12 mol% it decreased. This is probably because, at about 3 mol%, the tetragonal ZrO 2 completely remain and, at 12 mol%, the cubic ZrO 2 exists. In the cases of Nos. 5-8 where the amount of ZrO 2 was changed, no increase in strength is seen in the range where the amount of ZrO 2 is small, and if the amount of ZrO 2 is large, the strength increases but the hardness decreases, and therefore, not suitable for the substrate.
Nos. 13-18 are the cases where the carbide and nitride were added and are for comparison between those which have the addition to ZrO 2 and those which have not. In every case, the addition of ZrO 2 increases the breaking strength by upto 20 kg/m 2 , and it is clear that ZrO 2 improve the breaking strength.
TABLE 1__________________________________________________________________________ Existence Existence Relative of pore of chippingMixed composition (wt %) density Vickers of more of moreNo. Al.sub.2 O.sub.3 TiC Others (%) hardness than 1 μm than 1 μm__________________________________________________________________________ 1 75 25 -- 98.5 2000 Yes Yes 2 70 30 MgO: 0.5 98.8 2100 Yes Yes 3 70 30 MgO: 0.05 NiO: 1.0 99.0 2000 Yes Yes 4 70 30 SiO.sub.2 : 0.02 99.0 2050 Yes Yes 5 70 30 SiO.sub.2 : 1 >99.7 2000 No No 6 70 30 SiO.sub.2 : 8 >99.7 1700 No No 7 65 35 Fe.sub.2 O.sub.3 : 0.02 99.2 2050 Yes Yes 8 65 35 Fe.sub.2 O.sub.3 : 3 >99.7 2000 No No 9 65 35 Fe.sub.2 O.sub.3 : 8 >99.7 1800 No No10 70 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 >99.7 2100 No No11 70 30 SiO.sub.2 : 2 Cr.sub.2 O.sub.3 : 0.02 >99.7 2100 No No12 70 30 SiO.sub.2 : 2 Cr.sub.2 O.sub.3 : 1 >99.7 2000 No No13 70 30 SiO.sub.2 : 2 Cr.sub.2 O.sub.3 : 8 >99.7 1800 No No14 65 35 SiO.sub.2 : 2 WO.sub.3 : 0.02 >99.7 2000 No No15 65 35 SiO.sub.2 : 2 WO.sub.3 : 1.5 >99.7 2050 No No16 65 35 SiO.sub.2 : 2 WO.sub.3 : 8 >99.7 1700 No No17 70 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 1 WO.sub.3 : >99.7 2000 No No18 70 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 Cr.sub.2 O.sub.3 : >99.7 2000 No No__________________________________________________________________________
TABLE 2__________________________________________________________________________Mixed composition (wt %) Compound (TiC Existence Existence substitution Relative Particle of pore of of chipping amount by mol % density diameter more than more thanNo. Al.sub.2 O.sub.3 TiC in parentheses) Others (%) (μm) 1 μm 1 μm__________________________________________________________________________1 70 30 -- MgO: 0.5 NiO: 0.5 99.0 4-5 Yes Yes2 70 30 -- SiO.sub.2 : 2, Fe.sub.2 O.sub.3 : 2 >99.7 4-5 No No3 70 28 ZrC: 2(4) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 >99.7 3-4 No No4 70 20 ZrC: 10(22.5) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 >99.7 ≦1 No No5 70 5 ZrC: 25(74.4) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 99.0 ≦1 No No6 70 20 ZrC: 10(22.5) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 Cr.sub. 2 O.sub.3 : 2 >99.7 ≦1 No No7 70 20 ZrC: 10(22.5) MgO: 0.5 99.2 ≦1 No No8 70 20 VaC: 10(32.3) SiO.sub.2 : 3 ≧99.7 ≦1 No No9 70 20 Tac: 10(13.5) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 WO.sub.3 : >99.7 ≦1 No No10 70 20 HfC: 10(13.6) SiO.sub.2 : 3 >99.7 ≦1 No No11 70 15 TiN: 15(50.8) SiO.sub.2 : 3 >99.7 ≦1 No No12 70 15 ZrN: 15(36.4) SiO.sub.2 : 5 Fe.sub.2 O.sub.3 : 2 Cr.sub.2 O.sub.3 : 2 >99.7 ≦1 No No13 70 15 TaN: 15(23.5) SiO.sub.2 : 3 WO.sub.3 : 2 Fe.sub.2 O.sub.3 : >99.7 ≦1 No No14 70 10 HfC: 10(19.6) SiO.sub.2 : 2 WO.sub.3 : 3 Cr.sub.2 O.sub.3 : >99.7 ≦1 No No TiN: 10(18.2)15 70 10 ZrC: 10(22.4) SiO.sub.2 : 3 Te.sub.2 O.sub.3 : 2 >99.7 ≦ 1 No No TiN: 10(38.0)16 70 15 HfC: 10(13.8) SiO.sub.2 : 1 Fe.sub.2 O.sub.3 : 1 WO.sub.3 : >99.7 ≦1 No No VaC: 5(20.3)__________________________________________________________________________
TABLE 3__________________________________________________________________________Mixed composition (wt %) Stabilizer Compound ZrO.sub.2 (mol % to (TiC substitution (Al.sub.2 O.sub.3 substitution zirconia in in parenthesesNo. Al.sub.2 O.sub.3 in parentheses mol %) parentheses) TiC mol %) Others__________________________________________________________________________ 1 70 30 MgO: 0.5 NiO: 1.0 2 60 10(12.1) 30 MgO: 0.5 NiO: 1.0 3 70 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 4 60 10(12.1) 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 5 60 10(12.1) Y.sub.2 O.sub.3 : 0.54(3) 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 6 68 2(2.4) Y.sub.2 O.sub.3 : 0.11(3) 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 7 50 20(24.9) Y.sub.2 O.sub.3 : 1.1(3) 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 8 20 50(67.4) Y.sub.2 O.sub.3 : 2.2(3) 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 9 60 10(12.1) Y.sub.2 O.sub.3 : 0.18(1) 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 210 60 10(12.1) Y.sub.2 O.sub.3 : 2(12) 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 211 70 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 Cr.sub.2 O.sub.3 : 212 60 10(12.1) Y.sub.2 O.sub.3 : 0.54(3) 30 SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 Cr.sub.2 O.sub.3 : 213 70 20 ZrC: 10(22.5) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 214 60 10(12.1) Y.sub.2 O.sub.3 : 0.54(3) 20 ZrC: 10(22.5) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 215 70 20 TiC: 10(13.5) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 Cr.sub.2 O.sub.3 : 216 60 10(12.1) Y.sub.2 O.sub.3 : 0.54(3) 20 TiC: 10(13.5) SiO.sub.2 : 2 Fe.sub.2 O.sub.3 : 2 Cr.sub.2 O.sub.3 : 217 70 20 TiN: 10(50.5) SiO.sub.2 : 318 60 10(12.1) Y.sub.2 O.sub.3 : 0.54(3) 20 TiN: 10(50.8) SiO.sub.2 : 3__________________________________________________________________________ Existence Crystal Existence of chip- Relative particle Vickers Breaking of pore of ping of density diameter hardness strength more than more than No. (%) (μm) 200 kg (kg/m.sup.2) 1 μm 1 μm__________________________________________________________________________ 1 99.0 4-5 2000 50 Yes Yes 2 99.2 4-5 1900 55 Yes Yes 3 >99.7 ≦1 2100 50 No No 4 >99.7 ≦1 1900 57 No No 5 >99.7 ≦1 2000 73 No No 6 >99.7 ≦1 2100 52 No No 7 >99.7 ≦1 1900 75 No No 8 >99.7 ≦1 1600 80 No No 9 >99.7 ≦1 2000 60 No No 10 >99.7 ≦1 2000 50 No No 11 >99.7 ≦1 2000 50 No No 12 >99.7 ≦1 1950 72 No No 13 >99.7 ≦1 2000 52 No No 14 >99.7 ≦1 1950 74 No No 15 >99.7 ≦1 2050 50 No No 16 >99.7 ≦1 2000 69 No No 17 >99.7 ≦1 2100 53 No No 18 >99.7 ≦1 1950 71 No No__________________________________________________________________________
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A thin layer magnetic head comprising a ceramic substrate consisting essentially of 100 parts by weight of a ceramic material and 0.05 to 5 parts by weight of at least one compound from the group consisting of silicon oxide and iron oxide.
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FIELD OF THE INVENTION
This invention relates to a thermal treatment process for improving the resistance of a flux grown PPKTP (periodically poled potassium titanyl phosphate, KTiOPO 4 ) crystal to photo refractive damage and photo chromic damage when subjected to U.V., I.R. and/or visible light.
BACKGROUND OF THE INVENTION
The production of visible light (λ=400–700 nm) by means of second- harmonic generation in non-linear optical crystals is a known process. A preferred approach is to use a non-linear material which has been periodically poled. In this technique, the inherent wavelength conversion efficiency of the non-linear crystal is enhanced by imposing a periodic reversal in the orientation of the polarization of the crystal along the direction of light propagation. Potassium Titanyl Phosphate (KTP) is one non-linear crystalline material which is used in a number of applications in non-linear optics, including second- harmonic generation. For example, periodically poled potassium titanyl phosphate (PPKTP) has been used in the frequency doubling of near-infrared laser light to produce visible blue light. See, for example, WIPO Application No. 98/36109 for a detailed description of a method for transforming a crystal of KTP into (PPKTP) in order to permit quasi phase matching, which enhances conversion efficiency. Several workers with KTP have reported that, when used in frequency doubling, or other optical processes where UV, IR and/or visible light is transmitted for extended periods of time through a PPKTP crystal, whether grown by the older hydrothermal technique or by the currently preferred flux method, the crystal is subject to damage in service. Apparently this damage is caused by either or both of the input light (generally IR) and the output light (generally in the visible range or UV range) which results from the frequency doubling.
When used for frequency doubling, a variety of specific problems with the PPKTP crystal have been encountered, including photorefractive damage as manifested by:
i) changes in the size, shape and/or waist position of the frequency doubled beam and also beam astigmatism, and ii) a decline in the frequency doubled (second harmonic) beam spatial mode quality. iii) A change in the temperature at which second harmonic generation is optimal. This temperature is known as the phase matching temperature.
I will hereafter refer to these three effects as BSE for Beam Shift Effect.
Another problem is photochromic damage, one visible aspect of which is called “gray tracking”, which term is used to describe the appearance of discolored regions in the crystal. Gray tracking may be a visible indicia of increased absorption, which effect can significantly reduce the crystal's conversion efficiency and hence the laser's power output. Although the cause of photochromic damage is almost certainly not limited to the effect of the blue or other visible wavelength output light, we refer to this phenomenon as BIA for Blue Induced Absorption. This effect may also be due at least in part to the infrared pump beam which is being frequency doubled to produce the visible output light. If we consider the case of using a 976 nm IR pump laser to generate frequency doubled 488 nm blue light, the consequence of BIA is that the output power of the 976 nm gain chip has to be continuously increased over the operating life of the laser to compensate for the increased absorption (and hence reduced output) of the blue light by the PPKTP crystal. Compensation can be achieved by increasing the pump current to the gain chip, however, there is an upper limit beyond which the gain chip current cannot be safely raised without risking sudden chip failure.
It is by no means clear whether both BIA and BSE result from the same change or changes occurring in the crystal itself, but both effects are believed to occur as a result of the passage through the crystal of the pump and/or frequency doubled radiation for a prolonged period.
Over the past twenty years, a number of prior artworkers have endeavored to understand and/or solve the performance problems associated with the use of KTP and especially PPKTP for frequency conversion and other optical processes. The approaches have involved varying the crystal formation conditions, and/or treatment of the KTP crystal. To date, none of these approaches have proved wholly successful.
It seems clear that part of the problem prior artworkers have encountered in solving the KTP and PPKTP crystal degradation problem has been disagreement as to the mechanism, or more likely mechanisms, involved in such degradation. See, for example, “Nuclear Instruments and Methods in Physics Research” B, 141, pp 472–476 (1998); and J. Appl. Physics 87, 12, pp 8682–8687 (2000). At least some of the prior artworkers have postulated that the damage susceptibility of the PPKTP is due to deviation from stoichiometry (i.e., Potassium ion vacancies) in the crystal lattice. Hence, early workers tried annealing the crystal at the very high temperatures at which there would presumably be some mobility on the part of atoms present in the crystal lattice, in an effort to achieve a more uniform stoichiometry throughout the crystal. Other workers have investigated the effect of potassium non-stoichiometry on the crystal Curie temperature after high temperature (970° C.) heating in air, Appl. Phys. Lett. 67 (13) pp 1941–1943 (1995). Heating a KTP crystal in dry oxygen at 800° C., prior to poling to form PPKTP, has been reported to increase absorption at a wavelength of 500 nm., J. Appl. Phys. 73 (7), 2705 (1992), but conversely, heating in a wet Oxygen atmosphere at 800° C. is said to provide an improved crystal. Still other workers have suggested that synthesis of KTP in an Oxygen atmosphere affords a crystal having a stronger second-harmonic generation (SHG) signal, Solid State Comm. 91, 9, pp 757–759 (1994). However, later workers reported an improvement in transmission in the range 400–550 nm by growing the KTP crystals in an oxygen deficient ambient atmosphere, Appl. Phys. Lett. 69,(8) pp 1032–1034 (1996). The following review article describes much of the currently published literature on KTP and PPKTP: M. N. Satyanarayan, A. N. Deepthy and H. L. Bhat “Potassium Titanyl Phosphate and Its Isomorphs: Growth, Properties, and Applications”, Critical Reviews in Solid State and Materials Sciences, 24, 2, (1999), pp 103–189.
The extensive studies of KTP and/or PPKTP, only a few of which have been referred to above, while doubtless of scientific interest, have not provided a viable procedure for providing a KTP crystal and, in particular, a PPKTP crystal, which has a significantly reduced tendency to develop one or more of the previously enumerated problems, e.g., gray tracking, astigmatism, and other beam quality degradation when subjected to optical radiation for an extended period of service.
BRIEF DESCRIPTION OF THE INVENTION
I have found that thermal treatment (annealing) of flux grown PPKTP under a narrow range of thermal conditions significantly improves the resistance of the thus treated PPKTP crystals to the previously described deleterious photochromic and photorefractive defect formation. While the present invention will be described and exemplified primarily in the context of the conversion of near infrared light to blue visible light it is to be understood that when carrying out frequency conversion by a PPKTP crystal, the wavelength of the frequency doubled output light can be varied by an appropriate choice of input light wavelength and the size of the crystal grating period.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the Beam Shift Effect in that the beam waist shrinks and the beam waist position moves away from the source.
FIG. 2 shows the same effect by illustrating the change in beam configuration over time.
FIG. 3 shows the need to monitor and adjust the crystal operating temperature of a PPKTP crystal which has not been treated in accordance with the present invention to maintain optimum phase matching efficiency.
FIG. 4 compares the transmission of an untreated (“as is”) PPKTP crystal to a crystal that has been thermally treated (annealed) in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As previously indicated, in service the PPKTP frequency doubling crystal is known to undergo a variety of harmful changes in its performance characteristics over time. Among these changes are ones we refer to as Blue Induced Absorption (BIA) and Beam Shift Effect (BSE). Although it has not been definitely established, there is some evidence that both BIA and BSE are caused by the same or at least related changes which occur in the PPKTP crystal during operation, and that a treatment to the crystal that cures or at least ameliorates one condition will tend to ameliorate the other.
Considering first BSE, many users of blue lasers have very specific requirements for the optical beam parameters at the output of the laser, e.g., for beam waist diameter (650–750 μm) and waist location (±200 mm from the laser output window). When the PPKTP crystal undergoes changes over its operational life the beam waist will tend to decrease in diameter and move away from the laser output window. For many users these changes are not acceptable. These changes are illustrated in FIGS. 1 and 2 for an untreated crystal.
FIG. 1 shows the waist position and beam size Z and W respectively, at the start of service. As indicated above, in use the waist size will shrink and its position will tend to shift away from the laser output lens to W 1 and Z 1 , respectively. This effect is also illustrated in FIG. 2 which shows the effect of the BSE where the beam waist both shrinks and moves away from the laser output lens.
As already indicated, another BSE effect appears to be that the optimum phase matching temperature changes slightly. This results in either a loss in conversion efficiency and/or the need to provide means to both monitor the phase matching and also to adjust the temperature of the PPKTP crystal over its service life. This effect is illustrated in FIG. 3 , where to maintain optimum conversion efficiency for a PPKTP crystal over an 800 hour period of operation it was necessary to reduce the crystal temperature by 0.5° C. This imposes a non-trivial burden on the design of the laser.
We have found that all of the effects illustrated in FIGS. 1–3 are eliminated or, at least substantially ameliorated when the PPKTP crystal is treated in accordance with the present invention.
Another problem we have found to occur over the service life of the PPKTP crystal is the previously mentioned blue induced absorption (BIA). As previously discussed, this term is used to indicate the tendency of the PPKTP crystal over time to absorb an increasing percentage of the blue light generated by frequency doubling. Since the user of the laser requires a certain level of power output, such a BIA induced reduction in output over time may reduce the laser power output to an unacceptable level. BIA is usually, although not always, manifested by the appearance of so called “gray tracking” which denotes areas of darkening in the crystal. FIG. 4 illustrates the increased absorption (reduction in transmission) of an untreated (“as is”) PPKTP crystal in comparison with a PPKTP crystal annealed in accordance with the present invention at 325° C. for 16 hours. The pump laser in both cases was a semiconductor diode laser emitting at 976 nm. As can be seen, both crystals show an approximately the same initial transmissivity (normalized as 1.00). The transmissivity for each crystal then rises slightly in the first few hours of operation. However, the transmissivity of the untreated crystal almost immediately thereafter starts to decline steadily. In contrast, transmission by the PPKTP crystal, annealed in accordance with the present invention, decreases only very gradually over a prolonged period and even after 80 hours is still above its initial value. The point to be noted is that the “as is” (untreated) crystal has a steadily and significantly declining output of about 0.05%/hr. The crystal treated in accordance with the present invention shows a blue (frequency doubled wavelength) transmission decline at less than half that rate.
Four parameters define the boundaries of the novel process of the present invention in terms of providing a PPKTP crystal having improved resistance to both BSE and BIA. The process consists of annealing the PPKTP crystal where the following four parameters are kept within the hereinafter indicated ranges:
i) temperature range within which the PPKTP crystal is maintained during the annealing process; ii) duration at the annealing period; iii) composition of the atmosphere surrounding the crystal during annealing; and iv) rate at which the crystal is brought up to annealing temperature from ambient temperature (normally about 25° C.) and then back down to ambient temperature following annealing.
Discussing the above-indicated parameters in sequence we have found that:
i) the annealing temperature should be in the range of from about 200° C. up to about 400° C. Annealing at a temperature below 200° C. has been found not to produce a significant improvement in resistance within a reasonable time span to either photorefractive or photochromic damage. Conversely, annealing at a temperature above about 400° C., while effective at reducing photochromic defect formation, is undesirable in that it has been found to cause degradation in second-harmonic generation performance. Note that it is not critical that the annealing temperature be maintained absolutely constant during the annealing process; ii) to be fully effective, the annealing must be carried out for at least about 2 hours. Annealing for longer than about 60 hours is not deleterious particularly at the lower temperatures within the above-indicated range, but produces no significant additional performance enhancements for the crystal. Preferably the annealing time ranges from about 12 to about 48 hours; iii) we have found that the annealing atmosphere must contain at least 10% oxygen. Ambient air (ca. 21% O 2 ) has been found suitable and is clearly the most convenient annealing atmosphere. Providing an oxygen rich atmosphere (i.e. greater than 21% O 2 ) may reduce the anneal time required to produce the same degree of improvement in crystal performance, but at the cost of complicating the process. It does not appear that the moisture content of the annealing atmosphere has a significant positive or negative effect; and iv) to maintain good second-harmonic generation performance, while still improving the crystals resistance to damage, it is important that the heat-up and cool-down from and to ambient temperature, respectively, be relatively slow. I have found that it is important that the thermal ramp-up and ramp-down rates, which can be the same or different, be no greater than about 10° C./minute, preferably less than 10° C./minute. Heating at a rate of 15° C./minute has been found to cause substantial, thermally induced depoling of the PPKTP crystal. The minimum ramp rate, up and/or down, does not appear to be critical and is determined by practical considerations in the sense of the time required to carry out the annealing process.
To a certain extent, the lower the annealing temperature within the range 200° C. to 400° C., the longer the anneal time required to result in the same level of improvement in resistance to BIA and BSE. Conversely, it is undesirable to anneal for an extended period of time at temperatures in the range of about 360° C. to 400° C. as this tends to reduce the efficiency of second harmonic generation, although it does seem to reduce the tendency to BIA. I have found that optimum results are obtained by annealing at a temperature of from about 270° C. up to about 330° C. for a period of from at least about 12 hours up to about 60 hours and with a temperature ramp rate (both up and down) of from about 0.5° C. to about 5.0° C. per minute.
The foregoing detailed description of the invention includes passages that are chiefly or exclusively concerned with particular parts or aspects of the invention. It is to be understood that this is for clarity and convenience, that a particular feature may be relevant in more than just the passage in which it is disclosed, and that the disclosure herein includes all the appropriate combinations of information found in the different passages. Similarly, although the various figures and descriptions herein relate to specific embodiments of the invention, it is to be understood that where a specific feature is disclosed in the context of a particular figure or embodiment, such feature can also be used, to the extent appropriate, in the context of another figure or embodiment, in combination with another feature, or in the invention in general. Further, while the present invention has been particularly described in terms of certain preferred embodiments, the invention is not limited to such preferred embodiments. Rather, the scope of the invention is defined by the appended claims.
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A thermal treatment process for improving the resistance of a flux grown, periodically poled KTiOPO 4 crystal to photorefractive or photochromic damage comprising the steps of:
i) heating said crystal from ambient temperature up to an annealing temperature in the range of from about 200° C. to about 400° C.; ii) maintaining said crystal at said annealing temperature in an oxygen containing atmosphere; iii) allowing said crystal to slowly cool down from said annealing temperature to ambient temperature.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not applicable
TECHNICAL FIELD
[0005] This invention relates to the general field of sports, and more specifically toward a device that trains the user how to swing a bat effectively when playing a sport like baseball or softball.
BACKGROUND OF THE INVENTION
[0006] There are a variety of devices that have been developed to train players how to swing a bat to achieve a desired result when playing sports like baseball or softball. One of the most common training devices is a weighted bat such as that described in U.S. Patent application 2012/0220396 or weights that may be affixed to the end of the bat such as the donut weight. However, these devices do not train the player on proper orientation of the bat during a swing but merely strengthen the muscles that perform the swing. Other devices that utilize wind resistance have been developed to increase strength and include a parachute or fins attached to the end of a bat.
[0007] Other devices such as that described in U.S. Pat. No. 8,282,510 combine increased weight with a narrower hitting surface that mimics the center of a regular bat's hitting surface on the barrel. This narrower surface is intended to train the player to hit the center of the bat during a swing. However, these devices do not train a fixed orientation of the hands and wrist during a swing. More specifically this device is not designed to train the muscles that control the rotation of the wrist to maintain their orientation when swinging a bat.
[0008] U.S. Pat. No. 7,351,167 provides an adapter to be affixed to a bat that aids in maintaining the knuckles of the batter in the proper alignment during a swing. This elongated ridge that is positioned under the knuckles of the player when gripping the bat forcing the knuckles in a desired alignment when swinging. Unfortunately, the ridge creates an unnatural grip and does not prevent the rotation of the wrist when swinging the bat.
[0009] U.S. Pat. No. 7,041,017 is directed to a baseball training aid having a flat plane indicator on the knob of the device that “can be felt between the batter's wrist” that “will develop muscle memory so the user will create a level swing and develop proper hand placement on the bat”. The barrel of the bat is flat and “extends approximately 13 inches in length and extends along the longitudinal axis of the front portion of the bat.” Unfortunately, the flat plain indicator could cause injury if not used properly and is structurally different from a regulation bat used during play. In addition, the surface of the barrel has been flatted which prevents the user from creating muscle memory for hitting the center of the bat during a level swing. Consequently, this device does not distinguish on the muscle memory it creates. Meaning the muscle memory may be created for hitting the ball in the center of the bat but also for hitting the top surface creating a “pop-fly” as well as hitting the bottom surface creating a “grounder”.
[0010] Therefore, there is a need in the sports industry for a device that trains the user to maintain a desired orientation of the bat at the moment of contact, hit the ball on the center of the bat barrel, reduce rotation of the wrists during a swing and provides these characteristics in a device that closely resembles a normal regulation bat.
SUMMARY OF THE INVENTION
[0011] The present invention provides a bat swing training device comprising a bat having a means for maintaining the orientation of the bat during a swing. The device has a bottom end and a top end. The bottom end contains a knob, a non-round cylindrical-shaped handle next to the knob and a shaft next to said handle having a means for maintaining the desired orientation of the bat during a swing. The top end is a barrel next to said shaft where the ball contacts the device.
[0012] In one embodiment, the non-round cylindrical-shaped handle is approximately oval or rectangular in shape.
[0013] In another embodiment, the means for maintaining a desired bat orientation comprises a first bend in the shaft of about 45 to about 90 degrees and a second bend of about 45 to about 90 degrees wherein the first and second bends are in the plane of the handle and barrel. In one configuration of this embodiment, the first and second bends maintain the handle and barrel parallel to one another. This configuration may be a straightened “Z” with sharp corners or may be provided with more gradual corners forming an “S” shape.
[0014] In yet another embodiment, the means for maintaining a desired bat orientation comprises four bends in the shaft of about 45 to about 90 degrees wherein all four bends are in the plane of the handle and barrel. In one configuration of this embodiment, the four bends maintain the handle and barrel parallel to and in line with one another.
[0015] In still another embodiment, the means for maintaining a desired bat orientation comprises a weighted leverage bar affixed to and extending about perpendicular from said shaft.
[0016] Another aspect of this invention is a method for training a batter to swing a bat. The method comprises the steps of gripping the bat swing training device described above and swinging the device maintaining the bat in the proper orientation through the swing and directed away from an incoming ball when contacting the ball and repeating the swing until the desired orientation of the bat is maintained consistently over repeated swings.
DESCRIPTION OF THE FIGURES
[0017] FIG. 1 : (A) is a diagrammatic representation of one embodiment of the invention having two bends in the shaft, (B) is a diagrammatic representation of one embodiment of the invention having four bends in the shaft, and (C) is a diagrammatic representation of one embodiment of the invention having a weighted leverage bar.
DETAILED DESCRIPTION
[0018] Unless defined otherwise, all terms used herein have the same meaning as are commonly understood by one of skill in the art to which this invention belongs. All patents, patent applications and publications referred to throughout the disclosure herein are incorporated by reference in their entirety. In the event that there is a plurality of definitions for a term herein, those in this section prevail.
[0019] The phrase “means for maintaining a desired orientation”, “means for maintaining orientation”, “the means” or “means” as used herein refers to a configuration of the bat swing training device shaft or an element affixed to the device's shaft. When the means for maintaining the desired orientation is built into the configuration of the shaft a portion of the shaft extends from 45 to 90 degrees from the handle. During use that extension of the shaft is on the opposite side from the ball contact location on the barrel. When the means for maintaining the desired orientation is an element affixed to the shaft of the device, the weighted potion of the element extends a given distance and about 90 degrees from the handle on the opposite side from the ball contact location. In both cases, the configuration of the shaft or the element affixed to the shaft, the means acts as leverage creating a rotational force in the handle. This action requires that the user exert enough force with their grip to prevent rotation of the bat during the swing. By maintaining the orientation of the means during the swing it prevents rotation of the wrists increasing the chance of a desired contact with the ball and repeated uses of the bat swing training device results in muscle memory that will improve hitting.
[0020] The term “about” or “approximately” as used herein refer to an numerical value, amount or magnitude that may vary in a range from 1% to 15% and preferably from 5% to 10% or any specific percentage in either range.
[0021] The term “increase accuracy” as used herein refers to enabling the hitter to contact the ball at the center of the barrel, also referred to as “on the screws”, with more consistency reducing pop-up fly balls and lazy ground balls while increasing line drive hits.
[0022] The present invention provides a bat swing training device comprising a bat having a means for maintaining the orientation of the bat during a swing. The device has a bottom end and a top end. The bottom end contains a knob, a non-round cylindrical-shaped handle next to the knob and a shaft next to said handle having a means for maintaining the desired orientation of the bat during a swing. The top end is a barrel next to said shaft where the ball contacts the device.
I. Knob
[0023] The knob 2 is positioned at the base of the handle 4 of the device ( 10 , 20 and 30 ) and is provided as a stop for the hands of the user to prevent the device from inadvertently being released during a swing. It may be provided in a variety of shapes. In one embodiment, the knob 2 is round when viewed from the end of the device ( 10 , and 30 ) and oval when viewed from the side. In this configuration, the diameter of the knob 2 may be from about 40 mm to about 70 mm and has a thickness of from about 15 mm to about 30 mm. The angle formed between the knob 2 and the handle 4 may be 90 degrees. Alternatively, the side of the knob 2 contacting the handle may be sloped from the knob's perimeter edge to the handle's 4 surface. The angle created between this slope and the side of the knob 2 contacting the handle 4 may be from about 5 degrees to about 60 degrees. The diameter of the knob 2 , the thickness of the handle 4 and the angle of the slope will determine the distance the slope extends onto the handle 4 . So for example, if the knob 2 diameter is 40 mm having a thickness of 20 mm, with a handle 4 diameter of 25 mm and the slope angle from the handle 4 to the knob 2 being 30 degrees the distance along the handle 4 that the slope will occupy is about 13 mm. This distance may range from about 10 mm to about 50 mm.
[0024] The knob 2 may be made from a variety of materials including wood, polymer or metal. It may be made of the same or different material as the handle 4 , shaft 12 or barrel 18 . Preferably it is made of the same material as the handle 4 .
II. Handle
[0025] The handle 4 extends from the knob 2 and is provided in a sufficient length and texture to allow the user to securely grip the device ( 10 , 20 and 30 ) during use. The handle 4 may be provided in a variety of cross-sectional shapes. In one embodiment, the cross-section is round as is the case with regulation bats. In another embodiment, the shape aids the user in determining the orientation of the bat during a swing. For example, the cross-section may be square, oval or rectangular.
[0026] The handle 4 is straight as with regulations bats having a length that ranges from about 160 mm to about 350 mm and a diameter of about 25 mm to about 45 mm. The handle 4 may be provided with or without a textured coating for training purposes.
[0027] The handle 4 may be made from a variety of materials including wood, polymer or metal. It may be made of the same or different material as the shaft 12 or barrel 18 . Preferably it is made of the same material as the shaft 12 .
III. Means for Maintaining Orientation
[0028] The means for maintaining orientation 6 and 8 assists the user in maintaining the proper orientation of the device ( 10 , 20 and 30 ) during a swing, which results in muscle memory after repeated use of the device ( 10 , 20 and 30 ). This means 6 and 8 moves the device's ( 10 , 20 and 30 ) center of gravity from along its longitudinal axis to a fixed distance from the longitudinal axis of the handle 4 . By shifting the center of gravity the device ( 10 , 20 and 30 ) creates the normal downward gravitational force along the longitudinal axis as well as an additional rotational force exerted to the handle 4 . Moving the center of gravity may be accomplished by shifting a portion of the longitudinal axis of the shaft 12 and barrel 18 from the handle 4 or by providing a weighted element on the shaft 12 or barrel 18 that introduces rotational leverage on the handle 4 . In the latter configuration, the combination of the weighted element and the bat may be set to be the same weight as a conventional bat used by a batter if desired.
[0029] A number of configurations may be utilized to accomplish this orientation of the devices ( 10 , 20 and 30 ) center of gravity. For example, the barrel's longitudinal axis may be repositioned behind or in front of the longitudinal axis of the handle 4 , ( 10 ), a portion of the shaft 12 may be extended from the longitudinal axis of the device with sufficient weight to create rotational leverage at the handle 4 , ( 20 ) or a weighted leverage bar 8 may be affixed to the shaft 12 or barrel 18 of the device to create rotational leverage in the handle 4 , ( 30 ).
[0030] In one embodiment (see FIG. 1 A), the shaft 12 and barrel 18 are shifted from the longitudinal axis of the handle ( 10 ). This shift may be created by introducing two bends in the shaft 12 . These bends may be provided at angles ranging from about 45 degrees to about 90 degrees. The resulting configuration displaces the longitudinal axis of the handle 4 from the shaft 12 and barrel 18 from about 50 mm to about 150 mm. These bends may be sharp bends like those shown in FIG. 1A or may be more gradual forming the shape of an “S”.
[0031] In another embodiment (see FIG. 1B ), four bends are introduced into the shaft wherein the angles range from about 45 degrees to about 90 degrees ( 20 ). These bends can maintain the position of the longitudinal axis of the handle 4 and barrel 18 in alignment or may displace the longitudinal axis of the handle 4 from the shaft 12 and barrel 18 from about 50 mm to about 100 mm. In this embodiment, the handle 12 , barrel 18 and means 6 are in the same plane.
[0032] In yet another embodiment (see FIG. 1C ), a weighted leverage bar 8 having a clamping element on one end and weighted element on the other is affixed to the shaft 12 of barrel 18 of the device ( 30 ) to create the rotational leverage in the handle 4 .
[0033] In each of these embodiments the means 6 may be made from a variety of materials including polymer or metal. It may be made of the same or different material as the shaft 12 or barrel 18 . Preferably it is made of the same material as the barrel 18 and/or handle 4 .
IV. Barrel
[0034] The barrel 18 of the device ( 10 , 20 and 30 ) is constructed similarly to the barrel 18 of bats currently sold commercially or regulation bats utilized in the sports industry and are designed as the contact surface for the ball during use. The length and diameter of the barrel 18 will vary depending on the rules regulating the size, weight, shape and material of bats in the industry or for specialized play such as Little League for children or other sports that utilize a bat to hit a ball. In general, the barrel 18 of the bat usually widens from where is connects to the shaft 12 for a distance and then retains the larger diameter for a distance before terminating in the end of the device ( 10 , 20 and 30 ). The length of the barrel 18 may range from about 300 mm to about 675 mm with a diameter of about 60 mm to about 90 mm. The fixed diameter hitting surface of the barrel 18 may range in length from about 200 mm to about 350 mm.
[0035] In addition, the weight of the bat may be distributed differently among the elements depending on the desires of the batter. For example, a batter may prefer that a majority of the weight be distributed to the barrel while other may prefer that the barrel be lighter. Consequently the device of the resent invention will provide these options for the user.
Assembly
[0036] The device of the present invention may be provided in a single piece of may be constructed of multiple pieces. In a preferred embodiment the device is constructed of a single of polymer or metal that is form-molded, milled or extruded. Alternatively, the knob, handle and means may be made of one material and the shaft and barrel made of a different material or the knob, handle, and barrel may be made of one material and the means and shaft made of a different material. If more than on piece is utilized to prepare the device interlocking joints with adhesives or similar methods known in the art may be used to assure that the pieces do not come apart during use.
Use
[0037] The device may be used with automated and non-automated pitching. Before taking a batter's stance the device is held out in the position in which the user intends to contact the ball with the barrel of the device making sure that the means for maintaining orientation is about parallel to the ground. The bat is then drawn back for the swing and the user takes the batter's stance and readied for the pitch. When the pitch reaches the hitting zone after being released, the batter begins his/her swing making sure that the means for maintaining orientation is in the same position as it was when setting up for the pitch and at the moment of contacting the ball.
[0038] The induced rotational force on the handle will require that the batter securely grip the handle to prevent rotation and the orientation of the means will assist in assuring that the batter does not rotate his/her wrist when swing the device. The weight of the device may be increased with the addition of the means for maintaining orientation. More specifically, different weights may be utilized on the weighted leverage bar element or a heavier gauge material may be used in preparing the means. This will assist in increasing the force of the batter's swing when using a regulation bat.
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The present invention is a bat swing training device and methods of using the device to increase accuracy when hitting a ball with a bat. The training device has a bottom end having a knob, a handle next to the knob and a shaft next to the handle and a top end having a barrel for hitting the ball. The handle is a non-round-cylinder shape and the shaft has a means for maintaining a desired orientation of the bat at the moment of contacting a ball. The method includes the steps of gripping and swinging the training device while maintaining the desired orientation and repeating the swing improving hitting accuracy.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to beverage dispensing equipment and, in particular, to carbonating systems for beverage dispensing apparatus.
2. Background of the Invention
Post-Mix beverage dispensing equipment generally includes a carbonating tank for producing carbonated water. Such carbonating tanks typically have a still water inlet and a carbon dioxide inlet, as well as a carbonated water outlet for delivery of the carbonated water to a dispensing valve or valves. A high level of carbonation is generally desirable and a water pump is often employed for pumping the still water into the carbonation tank to provide the pressure head necessary for adequate carbonation. In high volume beverage dispensing environments, such as bottling plants or fast food restaurants, the size or cost of equipment to pressurize the carbonation tank is not a significant factor. However, beverage dispensing equipment is increasingly finding applications in low volume environments, such as private offices, and small retail outlets. The cost and size of equipment designed for such applications is always of prime concern. Therefore, a beverage dispensing apparatus that provides for high levels of carbonation, yet at a cost substantially lower than through the use of conventional carbonating systems, would be highly desirable.
SUMMARY OF THE INVENTION
The carbonating system of the present invention includes a pivotally mounted carbonating tank having a water inlet, an inlet for connecting to a pressurized source of carbon dioxide, a carbon dioxide vent outlet, and a carbonated water outlet. An electric motor is connected to the tank by an off-set or rocking mechanism for imparting a regular synchronous wave movement to the water in the tank.
As is known in the art, agitation of carbonated water results in release of the carbon dioxide dissolved therein. However, in the present invention the carbonation levels were found to be significantly improved by a gentle rocking motion being imparted to the carbonator and, hence the water contained therein. Specifically, a wave motion is created that provides for increased carbonation of the water above what would be provided by the pressure of the carbon dioxide alone.
As is known in the art, water is more easily carbonated at lower temperatures. Thus, in the preferred form of the present invention, the electric motor that imparts the motion to the carbonator also includes a fan for providing a circulation of cooled air from an evaporator over the pivotally mounted carbonating tank. As a further cooling strategy, the carbonating tank water inlet is connected to a source of pre-cooled water, such as heat exchange tubing extending in a serpentine fashion through an ice bank. The use of pre-cooled water further enhances the ability of the present invention to attain satisfactory levels of water carbonation.
DESCRIPTION OF THE DRAWINGS
A better understanding of the structure, operation, and objects and advantages of the present invention can be had in view of the following detailed description, which refers to the following figure, wherein:
FIG. 1 shows a schematic representation of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The carbonating apparatus of the present invention is seen in FIG. 1 and generally referred to by the numeral 10. Carbonating apparatus 10 includes a carbonator 12 and a pivotal mounting means 14 secured to the rigid structure of apparatus 10, such as a wall of a housing 16, shown in phantom outline. Carbonator 12 includes a water inlet 18, a carbon dioxide inlet 20, a carbonated water outlet 22, and a carbon dioxide vent outlet 24. An electric motor 26 includes a reduction drive 28 for connecting to a reciprocating means 30, which reciprocating means 30 is secured to carbonating tank 12. Motor 26 further includes a fan 32 being positioned adjacent an evaporator or cooling coil 34. As is understood by those of skill in the art, evaporator 34 is connected to a further refrigeration apparatus, such as a compressor and condenser (not shown). Vent outlet 24 includes a carbon dioxide vent solenoid 36. Inlet 20 includes a carbon dioxide control valve 38, and is connected to a source of pressurized carbon dioxide (not shown). Water inlet 18 includes a check valve 40 which is connected to a pre-cooling tank 42. Tank 42 is, in turn, connected to a source of potable water (not shown). Tank 42 is cooled, as for example, by placement in a refrigerated air space. Carbonated water outlet 22 is connected to a plurality of beverage or carbonated water dispensing valves (not shown).
A control 44 is connected to an upper liquid level switch 46 and a lower liquid level switch 48. Control 44 is also connected to vent solenoid 36, carbon dioxide solenoid 38, a manual regeneration switch 50, and a low carbonated water indicator light 52.
In operation, cooling tank 42 provides for the delivery of precooled water through inlet 18 into tank 12. As is understood in the art, check valve 40 prevents the reverse flow of carbonated water from tank 12 through inlet 18 towards the potable water source. When a sufficient volume of carbonated water has been withdrawn from carbonating tank 12, as sensed by low level sensor 48, control 44 closes carbon dioxide solenoid 38 and opens vent solenoid 36. As the water pressure from the potable water source is typically much lower than the carbon dioxide gas pressure, it can be appreciated that the coordinated closing of valve 38 and opening of valve 36 will permit the flow of water into tank 12. When sensor 46 indicates a sufficient volume of water in tank 12, control 44 then provides for the closing of valve 36 and the opening of valve 38.
Operation of motor 26, through reduction drive 28, serves to provide for a relatively slow oscillating or reciprocating movement of tank 12 about pivot 14. Thus, the carbon dioxide and water are gently mixed, in a manner below the level of agitation that would result in a release of carbon dioxide from the water, that instead provides for facilitating or enhancing the carbonation level of the resulting carbonated water. For example, in a cylindrical carbonation tank having an approximate internal volume of 3.5 liters, it was found, that pivoting movement about one end thereof through a total arc of approximately 30 degrees at 60 cycles per minute provided for a carbonation level of 3.8 volumes at 38 degrees temperature. One cycle being travel of the carbonator from, for example, a low point 15 degrees below to a high point 15 degrees above level and back to the low point. This carbonation level could be maintained with a flow rate of 400 oz. per hour. Moreover, in the present example, control 44 provided for oscillating of the carbonator five minutes each time sensor 48 signals control 44 to replenish carbonator 12 with water. The particular point of maximum carbonation is, of course, highly dependent upon the volume and structure of the carbonation tank; however, it is believed that the optimum carbonation is achieved in a manner substantially synchronous time of propagation of a wave movement of the water from one end of the tank to the other. It will be apparent to those of skill that many other cycling time approaches could be used depending upon design requirements. In particular, a constant cycling could be employed. The cyclical speed that yields maximum carbonation is, of course, highly dependent upon the volume and structure of the carbonation tank; however, it is believed that the optimum carbonation is achieved wherein the time required to move from a high position to a low one, or vice-versa, is substantially synchronous with the time it takes for a wave propagated by such motion to move from one end of the tank to the other.
In addition, the present invention can optionally include the cooling fan 32 for providing a circulation of cooled air from evaporator 34 across carbonating tank 12. In this manner, the carbonation level can be further enhanced. It will also be understood that the carbonation level can be further improved by providing pre-cooling of the water supply to tank 12, such as through the use of pre-cooling tank 42. Various other pre-cooling means can be used, such as a length of heat exchange tube extending in a serpentine fashion through an ice bank. It can be appreciated by those of skill that carbonation system 10 is most advantageously used in combination with a complete beverage dispensing equipment wherein such an ice bank is typically included.
As will be understood by those of skill in the art, various modifications can be made to the present invention and still remain within the scope thereof. For example, the point of pivotal attachment of the carbonating tank and the particular dimensions thereof are a matter of design choice.
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An apparatus for providing carbonating of water. The apparatus including a carbonating tank having a carbon dioxide inlet, a water inlet, and a carbonated water outlet. The carbonating tank is pivotally mounted to a rigid structure and connected to an electric motor for providing an undulating or rocking motion of the carbonator about its pivot mounting. The motion of the carbonating tank providing for carbonating of the water held therein.
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BACKGROUND OF THE INVENTION
The present invention relates to a freewheel to be used for the motive power transmission mechanism of vehicles, such as bicycles and motorcycles, and other machines.
In the conventional freewheel of this kind, a sprocket wheel having teeth at its periphery for engagement with a chain is provided at its inner circumferential surface, with saw-toothed ratchet teeth, and on a part of the periphery of the body which is fitted in the sprocket wheel there are provided pins which are always urged to protrude by a spring so that tips of the pins are brought into contact with the ratchet teeth. Under this arrangement, when the sprocket wheel is rotated in one direction, the body is rotated together with the sprocket wheel by engagement of the pins with the ratchet teeth, and when the wheel is rotated in the other direction or when the sprocket wheel rotates at a speed higher than the r.p.m. of the body, the pins are disengaged from the ratchet teeth so that the sprocket wheel rotates independent of the body.
In the above conventional method, in order to provide pins and ratchet teeth at the outer circumferential surface of the body, the body must have a comparatively large size. On the other and, a wheel having a smaller size raises problems with regard to manufacture and strength.
SUMMARY OF THE INVENTION
With the above discussion in mind, the present invention has been designed to eliminate the defect of the conventional freewheel by placing the ratchet part on the lateral side of the wheel and to provide a freewheel which makes it possible to dispose the ratchet mechanism always at a normal position, irrespective of the size of the sprocket wheel, to standardize the parts for simplification of manufacture, and to increase the number of pins so as to make the freewheel withstand a larger torque.
The present invention is directed to a freewheel which comprises a body member having screw threads at the peripheral surface thereof and a flange provided integrally at one end thereof. Pin-receiving holes are bored parallel with the axial center of the body. Pins or balls are fitted in the pin-receiving holes in such a manner that they are always urged to protrude outwardly therefrom by a spring. A sprocket wheel has formed in one lateral side thereof a number of pin-locking tapered grooves and is fitted on the body. A tightening ring is screwed onto the body to sandwich the sprocket wheel between the flange of the body and the tightening ring so that the sprocket wheel is supported in such a manner that it is allowed to rotate freely in only one direction.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show the construction of preferred embodiments of the present invention in which the freewheel is applied to a bicycle, and wherein
FIG. 1a, FIG. 1b and FIG. 1c are the vertical sections of different embodiments of the invention, and
FIG. 2a, FIG. 2b, FIG. 2c and FIG. 2d are drawings parts of the freewheel according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described hereinafter with reference to preferred embodiments.
In the drawing, the freewheel of the invention includes body 1. Formed on the inside of the body 1 are female screw threads 1a for screw engagement with the outer circumferential surface of a hub. The body 1 has on one lateral side thereof a flange 2, the inner surface of which supports one lateral side of a sprocket wheel. The body 1 has male screw threads 1b on its outer periphery.
One the inside of the flange 2 of the body 1, there are provided at least two pin-receiving holes 1c bored to extend parallel with the axial center of the body 1. These pin receiving holes 1c are arranged at appropriate intervals. In each pin receiving hole 1c, a spring 3 and an engagement device such as a pin 4 are fitted so that the pin 4 is urged to protrude partly outwardly from the inside surface 2a of the flange 2 by the spring force of the spring 3.
The number of the above pin-receiving holes 1c is determined according to the torque applied to the sprocket wheel. Depending on the springing force of the spring 3, a steel ball may be used in place of the pin 4.
Loosely fitted to the outer circumferential surface of the body 1 is a sprocket wheel 5 having a required number of teeth, and a number of pin locking grooves 5a are provided at equal intervals on one side of the sprocket wheel 5, i.e., on the side facing the inside surface 2a of the flange 2. The distance between the pin locking grooves 5a is made to correspond to the distance between the pin-receiving holes 1c so that all or some of the pins fitted in the pin-receiving holes 1c are simultaneously locked by or separated from the pin locking grooves 5a. The pin locking grooves 5a are of an elliptical shape and are aligned in a circumferential direction on one lateral surface of the sprocket wheel, as shown in FIG. 2a. Each of the pin locking grooves 5a is formed to have a tapered depth so that the groove 5a is deep at one end thereof and gradually becomes shallow toward the other end thereof until it finally rises to the same level as the sprocket wheel surface, as shown in FIG. 2d. Because of this configuration of the grooves 5a, both the sprocket wheel 5 and the body 1 are rotated together in only one direction by the engagement between the pins 4 and pin locking grooves 5a. In the case of rotation in the opposite direction, the pins 4 slide up the tapered surface of the grooves to release the engagement between the pins and the grooves, thus forming a type of the ratchet mechanism.
To the male screw 1b on the outer circumference of the body 1 is screwed a tightening ring. This tightening ring 7 is provided on one lateral side thereof with an annular ball-receiving groove 7a. In this ball-receiving groove 7a are placeda plurality of balls 6, and the tightening ring 7 is screwed to the male screw 1b in such a manner that ring 7 presses the balls 6 onto the adjacent lateral side of the sprocket wheel 5. Thus, the sprocket wheel 5 is rotatably supported between the tightening ring 7 and the flange 2 of the body 1. In one embodiment, the above-mentioned balls 6 are brought into tight contact with only one surface of the sprocket wheel as shown in FIG. 1c, but the balls 6 may be provided to be brought into tight contact with both surfaces of the sprocket wheel as shown in FIG. 2a and FIG. 2b. In this case, a ball-receiving groove 1d similar to the above-mentioned ball-receiving groove 7a is provided at a position radially outwardly of the pin-receiving holes 1c in the inner surface of the flange, as shown in FIG. 1a, or at a radially inwardly position of the pin-receiving holes 1c, as shown in FIG. 1b. A plurality of balls 6 are positioned in groove 1d to bring them into contact with the adjacent surface of the sprocket wheel 5. In this manner, the balls 6 are brought into contact with both lateral surfaces of the sprocket wheel to provide smooth rotation of the sprocket wheel in relation to the body and to prevent rotation problems which otherwise may be caused by a large torque. Also, the sprocket wheel is supported under pressure by balls 6 on the flange side, while it is allowed to rotate smoothly.
Moreover, annular recesses 5b may be provided on the lateral surfaces of the sprocket wheel 5 so that the balls 6 are at all times kept in contact with the same circumferential surfaces of the sprocket wheel. Furthermore, a cover C can be provided on both sides of the sprocket wheel 5 so as to cover the gap between the sprocket wheel 5 and the flange and the gap between the sprocket wheel and the tightening ring 7, thereby preventing entry of rain water, etc. into such gaps.
The present invention provides the advantages that since the ratchet mechanism is provided at one lateral side of the sprocket wheel, it becomes possible to dispose the ratchet mechanism at all time at a regular position, without regard to the size of the wheel, whereby manufacturing is made easy and the number of pins provided can easily be increased to withstand a larger torque.
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A freewheel to be used for the motive power transmission mechanism of vehicles, such as bicycles and motorcycles, and other machines, includes ratchet mechanism provided at one lateral side of a sprocket wheel.
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[0001] The present application is a continuation-in-part of U.S. patent application Ser. No. 13/270,840 filed Oct. 11, 2011. U.S. patent application Ser. No. 13/270,840 is a continuation of U.S. patent application Ser. No. 13/035,777 filed Feb. 25, 2011. U.S. patent application Ser. No. 13/035,777 claims the benefit of priority of U.S. Provisional Application No. 61/308,884, filed Feb. 26, 2010, and is also a continuation-in-part of International Patent Application No. PCT/US09/68818, filed Dec. 18, 2009. International Patent Application No. PCT/US09/68818 claims the benefit of priority of U.S. Provisional Application 61/139,470, filed Dec. 19, 2008. The present application also claims the benefit of priority of U.S. Provisional Patent Application No. 61/678,458 filed Aug. 1, 2012.
STATEMENT OF GOVERNMENT INTEREST
[0002] This invention was made with Government support under R21EY018491 awarded by the National Institutes of Health (NIH)/National Eye Institute (NEI), under R21NS064328, awarded by the NIH/National Institute of Neurological Disorders and Stroke (NINDS) and under RC2 NS69476-01 awarded by the National Institutes of Health (NIH). The Government has certain rights in the invention.
INCORPORATION BY REFERENCE OF THE SEQUENCE LISTING
[0003] This application contains, as a separate part of disclosure, a Sequence Listing in computer-readable form (filename: 44125CIP_SeqListing.txt; 4000 bytes—ASCII text file) which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0004] The present invention relates to Adeno-associated virus 9 methods and materials useful for systemically delivering polynucleotides across the blood brain barrier. Accordingly, the present invention also relates to methods and materials useful for systemically delivering polynucleotides to the central and peripheral nervous systems. The present invention also relates to Adeno-associated virus type 9 methods and materials useful for intrathecal delivery (i.e., delivery into the space under the arachnoid membrane of the brain or spinal cord) of polynucleotides. Use of the methods and materials is indicated, for example, for treatment of lower motor neuron diseases such as spinal muscle atrophy and amyotrophic lateral sclerosis as well as Pompe disease and lysosomal storage disorders. Use of the methods and materials is also indicated, for example, for treatment of Rett syndrome.
BACKGROUND
[0005] Large-molecule drugs do not cross the blood-brain-barrier (BBB) and 98% of small-molecules cannot penetrate this barrier, thereby limiting drug development efforts for many CNS disorders [Pardridge, W. M. Nat Rev Drug Discov 1: 131-139 (2002)]. Gene delivery has recently been proposed as a method to bypass the BBB [Kaspar, et al., Science 301: 839-842 (2003)]; however, widespread delivery to the brain and spinal cord has been challenging. The development of successful gene therapies for motor neuron disease will likely require widespread transduction within the spinal cord and motor cortex. Two of the most common motor neuron diseases are spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS), both debilitating disorders of children and adults, respectively, with no effective therapies to date. Recent work in rodent models of SMA and ALS involves gene delivery using viruses that are retrogradely transported following intramuscular injection [Kaspar et al., Science 301: 839-842 (2003); Azzouz et al., J Clin Invest 114: 1726-1731 (2004); Azzouz et al., Nature 429: 413-417 (2004); Ralph et al., Nat Med 11: 429-433 (2005)]. However, clinical development may be difficult given the numerous injections required to target the widespread region of neurodegeneration throughout the spinal cord, brainstem and motor cortex to effectively treat these diseases. Adeno-associated virus (AAV) vectors have also been used in a number of recent clinical trials for neurological disorders, demonstrating sustained transgene expression, a relatively safe profile, and promising functional responses, yet have required surgical intraparenchymal injections [Kaplitt et al., Lancet 369: 2097-2105 (2007); Marks et al., Lancet Neurol 7: 400-408 (2008); Worgall et al., Hum Gene Ther (2008)].
[0006] SMA is an early pediatric neurodegenerative disorder characterized by flaccid paralysis within the first six months of life. In the most severe cases of the disease, paralysis leads to respiratory failure and death usually by two years of age. SMA is the second most common pediatric autosomal recessive disorder behind cystic fibrosis with an incidence of 1 in 6000 live births. SMA is a genetic disorder characterized by the loss of lower motor neurons (LMNs) residing along the length of the entire spinal cord. SMA is caused by a reduction in the expression of the survival motor neuron (SMN) protein that results in denervation of skeletal muscle and significant muscle atrophy. SMN is a ubiquitously expressed protein that functions in U snRNP biogenesis.
[0007] In humans there are two very similar copies of the SMN gene termed SMN1 and SMN2. The amino acid sequence encoded by the two genes is identical. However, there is a single, silent nucleotide change in SMN2 in exon 7 that results in exon 7 being excluded in 80-90% of transcripts from SMN2. The resulting truncated protein, called SMNΔ7, is less stable and rapidly degraded. The remaining 10-20% of transcript from SMN2 encodes the full length SMN protein. Disease results when all copies of SMN1 are lost, leaving only SMN2 to generate full length SMN protein. Accordingly, SMN2 acts as a phenotypic modifier in SMA in that patients with a higher SMN2 copy number generally exhibit later onset and less severe disease.
[0008] To date, there are no effective therapies for SMA. Therapeutic approaches have mainly focused on developing drugs for increasing SMN levels or enhancing residual SMN function. Despite years of screening, no drugs have been fully effective for increasing SMN levels as a restorative therapy. A number of mouse models have been developed for SMA. See, Hsieh-Li et al., Nature Genetics, 24 (1): 66-70 (2000); Le et al., Hum. Mol. Genet., 14 (6): 845-857 (2005); Monani et al., J. Cell. Biol., 160 (1): 41-52 (2003) and Monani et al., Hum. Mol. Genet., 9 (3): 333-339 (2000). A recent study express a full length SMN cDNA in a mouse model and the authors concluded that expression of SMN in neurons can have a significant impact on symptoms of SMA. See Gavrilina et al., Hum. Mol. Genet., 17(8):1063-1075 (2008).
[0009] ALS is another disease that results in loss of muscle and/or muscle function. First characterized by Charcot in 1869, it is a prevalent, adult-onset neurodegenerative disease affecting nearly 5 out of 100,000 individuals. ALS occurs when specific nerve cells in the brain and spinal cord that control voluntary movement gradually degenerate. Within two to five years after clinical onset, the loss of these motor neurons leads to progressive atrophy of skeletal muscles, which results in loss of muscular function resulting in paralysis, speech deficits, and death due to respiratory failure.
[0010] The genetic defects that cause or predispose ALS onset are unknown, although missense mutations in the SOD-1 gene occurs in approximately 10% of familial ALS cases, of which up to 20% have mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1), located on chromosome 21. SOD-1 normally functions in the regulation of oxidative stress by conversion of free radical superoxide anions to hydrogen peroxide and molecular oxygen. To date, over 90 mutations have been identified spanning all exons of the SOD-1 gene. Some of these mutations have been used to generate lines of transgenic mice expressing mutant human SOD-1 to model the progressive motor neuron disease and pathogenesis of ALS.
[0011] De novo mutations in the X-linked gene encoding the transcription factor, Methyl-CpG binding protein 2 (MECP2), are the most frequent cause of the neurological disorder Rett syndrome (RTT). Hemizygous males usually die of neonatal encephalopathy. Heterozygous females survive into adulthood but exhibit severe symptoms including microcephaly, loss of purposeful hand motions and speech, and motor abnormalities which appear following a period of apparently normal development. Both male and female mouse models exhibit RTT-like behaviors [Guy et al., Nature Genetics, 27: 322-326 (2001); Chen et al., Nature Genetics 27: 327-331 (2001); and Katz et al., 5: 733-745 (2012)], but most studies have focused on males because of the shorter latency to and severity in symptoms. Despite encouraging studies on male mice, no therapeutic treatment has been shown yet to be effective in females, the more gender appropriate model.
[0012] AAV is a replication-deficient parvovirus, the single-stranded DNA genome of which is about 4.7 kb in length including 145 nucleotide inverted terminal repeat (ITRs). The nucleotide sequence of the AAV serotype 2 (AAV2) genome is presented in Srivastava et al., J Virol, 45: 555-564 (1983) as corrected by Ruffing et al., J Gen Virol, 75: 3385-3392 (1994). Cis-acting sequences directing viral DNA replication (rep), encapsidation/packaging and host cell chromosome integration are contained within the ITRs. Three AAV promoters (named p5, p19, and p40 for their relative map locations) drive the expression of the two AAV internal open reading frames encoding rep and cap genes. The two rep promoters (p5 and p19), coupled with the differential splicing of the single AAV intron (at nucleotides 2107 and 2227), result in the production of four rep proteins (rep 78, rep 68, rep 52, and rep 40) from the rep gene. Rep proteins possess multiple enzymatic properties that are ultimately responsible for replicating the viral genome. The cap gene is expressed from the p40 promoter and it encodes the three capsid proteins VP1, VP2, and VP3. Alternative splicing and non-consensus translational start sites are responsible for the production of the three related capsid proteins. A single consensus polyadenylation site is located at map position 95 of the AAV genome. The life cycle and genetics of AAV are reviewed in Muzyczka, Current Topics in Microbiology and Immunology, 158: 97-129 (1992).
[0013] AAV possesses unique features that make it attractive as a vector for delivering foreign DNA to cells, for example, in gene therapy. AAV infection of cells in culture is noncytopathic, and natural infection of humans and other animals is silent and asymptomatic. Moreover, AAV infects many mammalian cells allowing the possibility of targeting many different tissues in vivo. Moreover, AAV transduces slowly dividing and non-dividing cells, and can persist essentially for the lifetime of those cells as a transcriptionally active nuclear episome (extrachromosomal element). The AAV proviral genome is infectious as cloned DNA in plasmids which makes construction of recombinant genomes feasible. Furthermore, because the signals directing AAV replication, genome encapsidation and integration are contained within the ITRs of the AAV genome, some or all of the internal approximately 4.3 kb of the genome (encoding replication and structural capsid proteins, rep-cap) may be replaced with foreign DNA such as a gene cassette containing a promoter, a DNA of interest and a polyadenylation signal. The rep and cap proteins may be provided in trans. Another significant feature of AAV is that it is an extremely stable and hearty virus. It easily withstands the conditions used to inactivate adenovirus (56° to 65° C. for several hours), making cold preservation of AAV less critical. AAV may even be lyophilized. Finally, AAV-infected cells are not resistant to superinfection.
[0014] Multiple serotypes of AAV exist and offer varied tissue tropism. Known serotypes include, for example, AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10 and AAV11. AAV9 is described in U.S. Pat. No. 7,198,951 and in Gao et al., J. Virol., 78: 6381-6388 (2004). Advances in the delivery of AAV6 and AAV8 have made possible the transduction by these serotypes of skeletal and cardiac muscle following simple systemic intravenous or intraperitoneal injections. See Pacak et al., Circ. Res., 99(4): 3-9 (1006) and Wang et al., Nature Biotech., 23(3): 321-8 (2005). The use of AAV to target cell types within the central nervous system, though, has required surgical intraparenchymal injection. See, Kaplitt et al., supra; Marks et al., supra and Worgall et al., supra.
[0015] There thus remains a need in the art for methods and vectors for delivering genes across the BBB.
SUMMARY
[0016] The present invention provides methods and materials useful for systemically delivering polynucleotides across the BBB. The present invention also provides methods and materials useful for intrathecal delivery of polynucleotides to the central nervous system.
[0017] In one aspect, the invention provides methods of delivering a polynucleotide across the BBB comprising systemically administering a recombinant AAV9 (rAAV9) with a genome including the polynucleotide to a patient. In some embodiments, the rAAV9 genome is a self complementary genome. In other embodiments, the rAAV9 genome is a single-stranded genome.
[0018] In some embodiments, the methods systemically deliver polynucleotides across the BBB to the central and/or peripheral nervous system. Accordingly, a method is provided of delivering a polynucleotide to the central nervous system comprising systemically administering a rAAV9 with a self-complementary genome including the genome to a patient. In some embodiments, the polynucleotide is delivered to brain. In some embodiments, the polynucleotide is delivered to the spinal cord. Also provided is a method of delivering a polynucleotide to the peripheral nervous system comprising systemically administering a rAAV9 with a self-complementary genome including the polynucleotide to a patient is provided. In some embodiments, the polynucleotide is delivered to a lower motor neuron.
[0019] In another aspect, the invention provides methods of delivering a polynucleotide to the central nervous system of a patient in need thereof comprising intrathecal delivery of rAAV9 with a genome including the polynucleotide. In some embodiments, rAAV9 genome is a self-complementary genome. In some embodiments, a non-ionic, low-osmolar contrast agent is also delivered to the patient, for example, iobitridol, iohexyl, iomeprol, iopamidol, iopentol, iopromide, ioversol or ioxilan.
[0020] Embodiments of the invention employ rAAV9 to deliver polynucleotides to nerve and glial cells. In some aspects, the glial cell is a microglial cell, an oligodendrocyte or an astrocyte. In other aspects the rAAV9 is used to deliver a polynucleotide to a Schwann cell.
[0021] Use of the systemic or intrathecal delivery methods is indicated, for example, for lower motor neuron diseases such as SMA and ALS as well as Pompe disease, lysosomal storage disorders, Glioblastoma multiforme and Parkinson's disease. Lysosomal storage disorders include, but are not limited to, Activator Deficiency/GM2 Gangliosidosis, Alpha-mannosidosis, Aspartylglucosaminuria, Cholesteryl ester storage disease, Chronic Hexosaminidase A Deficiency, Cystinosis, Danon disease, Fabry disease, Farber disease, Fucosidosis, Galactosialidosis, Gaucher Disease (Type I, Type II, Type III), GM1 gangliosidosis (Infantile, Late infantile/Juvenile, Adult/Chronic), I-Cell disease/Mucolipidosis II, Infantile Free Sialic Acid Storage Disease/ISSD, Juvenile Hexosaminidase A Deficiency, Krabbe disease (Infantile Onset, Late Onset), Metachromatic Leukodystrophy, Mucopolysaccharidoses disorders (Pseudo-Hurler polydystrophy/Mucolipidosis IIIA, MPSI Hurler Syndrome, MPSI Scheie Syndrome, MPS I Hurler-Scheie Syndrome, MPS II Hunter syndrome, Sanfilippo syndrome Type A/MPS III A, Sanfilippo syndrome Type B/MPS III B, Sanfilippo syndrome Type C/MPS III C, Sanfilippo syndrome Type D/MPS III D, Morquio Type A/MPS WA, Morquio Type B/MPS IVB, MPS IX Hyaluronidase Deficiency, MPS VI Maroteaux-Lamy, MPS VII Sly Syndrome, Mucolipidosis I/Sialidosis, Mucolipidosis IIIC, Mucolipidosis type IV), Multiple sulfatase deficiency, Niemann-Pick Disease (Type A, Type B, Type C), Neuronal Ceroid Lipofuscinoses (CLN6 disease (Atypical Late Infantile, Late Onset variant, Early Juvenile), Batten-Spielmeyer-Vogt/Juvenile NCL/CLN3 disease, Finnish Variant Late Infantile CLN5, Jansky-Bielschowsky disease/Late infantile CLN2/TPP1 Disease, Kufs/Adult-onset NCL/CLN4 disease, Northern Epilepsy/variant late infantile CLN8, Santavuori-Haltia/Infantile CLN1/PPT disease, Beta-mannosidosis, Pompe disease/Glycogen storage disease type II, Pycnodysostosis, Sandhoff Disease/Adult Onset/GM2 Gangliosidosis, Sandhoff Disease/GM2 gangliosidosis—Infantile, Sandhoff Disease/GM2 gangliosidosis—Juvenile, Schindler disease, Salla disease/Sialic Acid Storage Disease, Tay-Sachs/GM2 gangliosidosis, Wolman disease.
[0022] In further embodiments, use of the systemic or intrathecal delivery methods is indicated for treatment of nervous system disease such as Rett Syndrome, Alzheimer's Disease, Parkinson's Disease, Huntington's Disease along with nervous system injury including spinal cord and brain trauma/injury, stroke, and brain cancers. In some embodiments, methods of treatment of Rett syndrome are contemplated where the methods deliver a polynucleotide to the central nervous system of a patient in need thereof by systemic delivery of rAAV9 with a genome including the polynucleotide. In some embodiments, methods of treatment of Rett syndrome are contemplated where the methods deliver a polynucleotide to the central nervous system of a patient in need thereof by intrathecal delivery of rAAV9 with a genome including the polynucleotide.
[0023] In yet another aspect, the invention provides rAAV genomes. The rAAV genomes comprise one or more AAV ITRs flanking a polynucleotide encoding a polypeptide (including, but not limited to, an SMN polypeptide) or encoding short hairpin RNAs directed at mutated proteins or control sequences of their genes. The polynucleotide is operatively linked to transcriptional control DNAs, specifically promoter DNA and polyadenylation signal sequence DNA that are functional in target cells to form a gene cassette. The gene cassette may also include intron sequences to facilitate processing of an RNA transcript when expressed in mammalian cells.
[0024] In some aspects, the rAAV9 genome encodes a trophic or protective factor. In various embodiments, use of a trophic or protective factor is indicated for neurodegenerative disorders contemplated herein, including but not limited to Alzheimer's Disease, Parkinson's Disease, Huntington's Disease along with nervous system injury including spinal cord and brain trauma/injury, stroke, and brain cancers. Non-limiting examples of known nervous system growth factors include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), neurotrophin-4/5 (NT-4/5), neurotrophin-6 (NT-6), ciliary neurotrophic factor (CNTF), glial cell line-derived neurotrophic factor (GDNF), the fibroblast growth factor family (e.g., FGF's 1-15), leukemia inhibitory factor (LIF), certain members of the insulin-like growth factor family (e.g., IGF-1), the neurturins, persephin, the bone morphogenic proteins (BMPs), the immunophilins, the transforming growth factor (TGF) family of growth factors, the neuregulins, epidermal growth factor (EGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor family (e.g. VEGF 165), follistatin, Hif1, and others. Also generally contemplated are zinc finger transcription factors that regulate each of the trophic or protective factors contemplated herein. In further embodiments, methods to modulate neuro-immune function are contemplated, including but not limited to, inhibition of microglial and astroglial activation through, for example, NFkB inhibition, or NFkB for neuroprotection (dual action of NFkB and associated pathways in different cell types.) by siRNA, shRNA, antisense, or miRNA. In still further embodiments, the rAAV9 genome encodes an apoptotic inhibitor (e.g., bcl2, bclxL). Use of a rAAV9 encoding a trophic factor or spinal cord injury modulating protein or a suppressor of an inhibitor of axonal growth (e.g., a suppressor of Nogo [Oertle et al., The Journal of Neuroscience, 23(13):5393-5406 (2003)] is also contemplated for treating spinal cord injury.
[0025] In some embodiments, use of materials and methods of the invention is indicated for neurodegenerative disorders such as Parkinson's disease. In various embodiments, the rAAV9 genome may encode, for example, Aromatic acid dopa decarboxylase (AADC), Tyrosine hydroxylase, GTP-cyclohydrolase 1 (gtpch1), apoptotic inhibitors (e.g., bcl2, bclxL), glial cell line-derived neurotrophic factor (GDNF), the inhibitory neurotransmitter-amino butyric acid (GABA), and enzymes involved in dopamine biosynthesis. In further embodiments, the rAAV9 genome may encode, for example, modifiers of Parkin and/or synuclein.
[0026] In some embodiments, use of materials and methods of the invention is indicated for neurodegenerative disorders such as Alzheimer's disease. In further embodiments, methods to increase acetylcholine production are contemplated. In still further embodiments, methods of increasing the level of a choline acetyltransferase (ChAT) or inhibiting the activity of an acetylcholine esterase (AchE) are contemplated.
[0027] In some embodiments, the rAAV9 genome may encode, for example, methods to decrease mutant Huntington protein (htt) expression through siRNA, shRNA, antisense, and/or miRNA for treating a neurodegenerative disorder such as Huntington's disease.
[0028] In some embodiments, use of materials and methods of the invention is indicated for neurodegenerative disorders such as ALS. In some aspects, treatment with the embodiments contemplated by the invention results in a decrease in the expression of molecular markers of disease, such as TNFα, nitric oxide, peroxynitrite, and/or nitric oxide synthase (NOS).
[0029] In other aspects, the vectors could encode short hairpin RNAs directed at mutated proteins such as superoxide dismutase for ALS, or neurotrophic factors such as GDNF or IGF1 for ALS or Parkinson's disease.
[0030] In some embodiments, use of materials and methods of the invention is indicated for preventing or treating neurodevelopmental disorders such as Rett Syndrome. For embodiments relating to Rett Syndrome, the rAAV9 genome may encode, for example, methyl cytosine binding protein 2 (MECP2).
[0031] The rAAV genomes of the invention lack AAV rep and cap DNA. AAV DNA in the rAAV genomes (e.g., ITRs) may be from any AAV serotype for which a recombinant virus can be derived including, but not limited to, AAV serotypes AAV-1, AAV-2, AAV-3, AAV-4, AAV-5, AAV-6, AAV-7, AAV-8, AAV-9, AAV-10 and AAV-11. The nucleotide sequences of the genomes of the AAV serotypes are known in the art. For example, the complete genome of AAV-1 is provided in GenBank Accession No. NC — 002077; the complete genome of AAV-2 is provided in GenBank Accession No. NC 001401 and Srivastava et al., J. Virol., 45: 555-564 {1983); the complete genome of AAV-3 is provided in GenBank Accession No. NC — 1829; the complete genome of AAV-4 is provided in GenBank Accession No. NC — 001829; the AAV-5 genome is provided in GenBank Accession No. AF085716; the complete genome of AAV-6 is provided in GenBank Accession No. NC — 00 1862; at least portions of AAV-7 and AAV-8 genomes are provided in GenBank Accession Nos. AX753246 and AX753249, respectively; the AAV-9 genome is provided in Gao et al., J. Virol., 78: 6381-6388 (2004); the AAV-10 genome is provided in Mol. Ther., 13(1): 67-76 (2006); and the AAV-11 genome is provided in Virology, 330(2): 375-383 (2004).
[0032] In another aspect, the invention provides DNA plasmids comprising rAAV genomes of the invention. The DNA plasmids are transferred to cells permissible for infection with a helper virus of AAV (e.g., adenovirus, E1-deleted adenovirus or herpesvirus) for assembly of the rAAV genome into infectious viral particles. Techniques to produce rAAV particles, in which an AAV genome to be packaged, rep and cap genes, and helper virus functions are provided to a cell are standard in the art. Production of rAAV requires that the following components are present within a single cell (denoted herein as a packaging cell): a rAAV genome, AAV rep and cap genes separate from (i.e., not in) the rAAV genome, and helper virus functions. The AAV rep and cap genes may be from any AAV serotype for which recombinant virus can be derived and may be from a different AAV serotype than the rAAV genome ITRs, including, but not limited to, AAV serotypes AAV-1, AAV-2, AAV-3, AAV-4, AAV-5, AAV-6, AAV-7, AAV-8, AAV-9, AAV-10 and AAV-11. Production of pseudotyped rAAV is disclosed in, for example, WO 01/83692 which is incorporated by reference herein in its entirety. In various embodiments, AAV capsid proteins may be modified to enhance delivery of the recombinant vector. Modifications to capsid proteins are generally known in the art. See, for example, US 20050053922 and US 20090202490, the disclosures of which are incorporated by reference herein in their entirety.
[0033] A method of generating a packaging cell is to create a cell line that stably expresses all the necessary components for AAV particle production. For example, a plasmid (or multiple plasmids) comprising a rAAV genome lacking AAV rep and cap genes, AAV rep and cap genes separate from the rAAV genome, and a selectable marker, such as a neomycin resistance gene, are integrated into the genome of a cell. AAV genomes have been introduced into bacterial plasmids by procedures such as GC tailing (Samulski et al., 1982, Proc. Natl. Acad. S6. USA, 79:2077-2081), addition of synthetic linkers containing restriction endonuclease cleavage sites (Laughlin et al., 1983, Gene, 23:65-73) or by direct, blunt-end ligation (Senaphthy & Carter, 1984, J. Biol. Chem., 259:4661-4666). The packaging cell line is then infected with a helper virus such as adenovirus. The advantages of this method are that the cells are selectable and are suitable for large-scale production of rAAV. Other examples of suitable methods employ adenovirus or baculovirus rather than plasmids to introduce rAAV genomes and/or rep and cap genes into packaging cells.
[0034] General principles of rAAV production are reviewed in, for example, Carter, 1992, Current Opinions in Biotechnology, 1533-539; and Muzyczka, 1992, Curr. Topics in Microbial. and Immunol., 158:97-129). Various approaches are described in Ratschin et al., Mol. Cell. Biol. 4:2072 (1984); Hermonat et al., Proc. Natl. Acad. Sci. USA, 81:6466 (1984); Tratschin et al., Mol. Cell. Biol. 5:3251 (1985); McLaughlin et al., J. Virol., 62:1963 (1988); and Lebkowski et al., 1988 Mol. Cell. Biol., 7:349 (1988). Samulski et al. (1989, J. Virol., 63:3822-3828); U.S. Pat. No. 5,173,414; WO 95/13365 and corresponding U.S. Pat. No. 5,658,776; WO 95/13392; WO 96/17947; PCT/U598/18600; WO 97/09441 (PCT/US96/14423); WO 97/08298 (PCT/US96/13872); WO 97/21825 (PCT/US96/20777); WO 97/06243 (PCT/FR96/01064); WO 99/11764; Perrin et al. (1995) Vaccine 13:1244-1250; Paul et al. (1993) Human Gene Therapy 4:609-615; Clark et al. (1996) Gene Therapy 3:1124-1132; U.S. Pat. No. 5,786,211; U.S. Pat. No. 5,871,982; and U.S. Pat. No. 6,258,595. Single-stranded rAAV are specifically contemplated. The foregoing documents are hereby incorporated by reference in their entirety herein, with particular emphasis on those sections of the documents relating to rAAV production.
[0035] The invention thus provides packaging cells that produce infectious rAAV. In one embodiment packaging cells may be stably transformed cancer cells such as HeLa cells, 293 cells and PerC.6 cells (a cognate 293 line). In another embodiment, packaging cells are cells that are not transformed cancer cells such as low passage 293 cells (human fetal kidney cells transformed with E1 of adenovirus), MRC-5 cells (human fetal fibroblasts), WI-38 cells (human fetal fibroblasts), Vero cells (monkey kidney cells) and FRhL-2 cells (rhesus fetal lung cells).
[0036] In still another aspect, the invention provides rAAV (i.e., infectious encapsidated rAAV particles) comprising a rAAV genome of the invention. In some embodiments, the rAAV genome is a self-complementary genome.
[0037] In some embodiments, the invention includes, but is not limited to, the exemplified rAAV named “rAAV SMN.” The rAAV SMN genome has in sequence an AAV2 ITR, the chicken β-actin promoter with a cytomegalovirus enhancer, an SV40 intron, the SMN coding DNA set out in SEQ ID NO: 1 (GenBank Accession Number NM — 000344.2), a polyadenylation signal sequence from bovine growth hormone and another AAV2 ITR. Conservative nucleotide substitutions of SMN DNA are also contemplated (e.g., a guanine to adenine change at position 625 of GenBank Accession Number NM — 000344.2). The genome lacks AAV rep and cap DNA, that is, there is no AAV rep or cap DNA between the ITRs of the genome. SMN polypeptides contemplated include, but are not limited to, the human SMN1 polypeptide set out in NCBI protein database number NP — 000335.1. Also contemplated is the SMN1-modifier polypeptide plastin-3 (PLS3) [Oprea et al., Science 320(5875): 524-527 (2008)]. Sequences encoding other polypeptides may be substituted for the SMN DNA.
[0038] Other rAAV9 are provided such as a rAAV9 named “scAAV9 MECP2.” Its genome has in sequence an AAV2 ITR missing the terminal resolution site, an approximately 730 bp murine MECP2 promoter fragment, SV40 intron sequences, murine MECP2 coding sequences, a bovine growth hormone polyadenylation signal sequence and an AAV2 ITR. The scAAV9 MECP2 genome lacks AAV rep and cap DNA, that is, there is no AAV rep or cap DNA between the ITRs of the genome. Yet another rAAV9 provided is a rAAV9 named “scAAV9 hMECP2.” Its genome has in sequence an AAV2 ITR missing the terminal resolution site, an approximately 730 bp murine MECP2 promoter fragment, SV40 intron sequences, human MECP2α coding sequences, a bovine growth hormone polyadenylation signal sequence and an AAV2 ITR. The scAAV9 hMECP2 genome lacks AAV rep and cap DNA, that is, there is no AAV rep or cap DNA between the ITRs of the genome. Substitution of human MECP2 promoter sequences for the corresponding murine MECP2 promoter sequences is specifically contemplated.
[0039] The rAAV of the invention may be purified by methods standard in the art such as by column chromatography or cesium chloride gradients. Methods for purifying rAAV vectors from helper virus are known in the art and include methods disclosed in, for example, Clark et al., Hum. Gene Ther., 10(6): 1031-1039 (1999); Schenpp and Clark, Methods Mol. Med., 69 427-443 (2002); U.S. Pat. No. 6,566,118 and WO 98/09657.
[0040] In another aspect, the invention contemplates compositions comprising rAAV of the present invention. In one embodiment, compositions of the invention comprise a rAAV encoding a SMN polypeptide. In another embodiment, compositions of the invention comprise a rAAV encoding a MECP2 polypeptide. In other embodiments, compositions of the present invention may include two or more rAAV encoding different polypeptides of interest.
[0041] Compositions of the invention comprise rAAV in a pharmaceutically acceptable carrier. The compositions may also comprise other ingredients such as diluents and adjuvants. Acceptable carriers, diluents and adjuvants are nontoxic to recipients and are preferably inert at the dosages and concentrations employed, and include buffers such as phosphate, citrate, or other organic acids; antioxidants such as ascorbic acid; low molecular weight polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; and/or nonionic surfactants such as Tween, pluronics or polyethylene glycol (PEG).
[0042] Titers of rAAV to be administered in methods of the invention will vary depending, for example, on the particular rAAV, the mode of administration, the treatment goal, the individual, and the cell type(s) being targeted, and may be determined by methods standard in the art. Titers of rAAV may range from about 1×10 6 , about 1×10 7 , about 1×10 8 , about 1×10 9 , about 1×10 10 , about 1×10 11 , about 1×10 12 , about 1×10 13 to about 1×10 14 or more DNase resistant particles (DRP) per ml. Dosages may also be expressed in units of viral genomes (vg). Dosages may also vary based on the timing of the administration to a human. These dosages of rAAV may range from about 1×10 11 vg/kg, about 1×10 12 , about 1×10 13 , about 1×10 14 , about 1×10 15 , about 1×10 16 or more viral genomes per kilogram body weight in an adult. For a neonate, the dosages of rAAV may range from about 1×10 11 , about 1×10 12 , about 3×10 12 , about 1×10 13 , about 3×10 13 , about 1×10 14 , about 3×10 14 , about 1×10 15 , about 3×10 15 , about 1×10 16 , about 3×10 16 or more viral genomes per kilogram body weight.
[0043] Methods of transducing nerve or glial target cells with rAAV are contemplated by the invention. The methods comprise the step of administering an intravenous or intrathecal effective dose, or effective multiple doses, of a composition comprising a rAAV of the invention to an animal (including a human being) in need thereof. If the dose is administered prior to development of a disorder/disease, the administration is prophylactic. If the dose is administered after the development of a disorder/disease, the administration is therapeutic. In embodiments of the invention, an effective dose is a dose that alleviates (eliminates or reduces) at least one symptom associated with the disorder/disease state being treated, that slows or prevents progression to a disorder/disease state, that slows or prevents progression of a disorder/disease state, that diminishes the extent of disease, that results in remission (partial or total) of disease, and/or that prolongs survival. Examples of disease states contemplated for treatment by methods of the invention are listed herein above.
[0044] Combination therapies are also contemplated by the invention. Combination as used herein includes both simultaneous treatment or sequential treatments. Combinations of methods of the invention with standard medical treatments (e.g., riluzole in ALS) are specifically contemplated, as are combinations with novel therapies.
[0045] Route(s) of administration and serotype(s) of AAV components of rAAV (in particular, the AAV ITRs and capsid protein) of the invention may be chosen and/or matched by those skilled in the art taking into account the infection and/or disease state being treated and the target cells/tissue(s).
[0046] In some embodiments, administration of the rAAV9 to the patient is contemplated to occur at postnatal day 1 (P1). In some embodiments, administration is contemplated to occur at P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14, P15, P16, P17, P18, P19, P20, P21, P22, P23, P24, P25, P26, P27, P28, P29, P30, P31, P32, P33, P34, P35, P36, P37, P38, P39, P40, P41, P42, P43, P44, P45, P46, P47, P48, P49, P50, P51, P52, P53, P54, P55, P56, P57, P58, P59, P60, P61, P62, P63, P64, P65, P66, P67, P68, P69, P70, P71, P72, P73, P74, P75, P76, P77, P78, P79, P80, P81, P82, P83, P84, P85, P86, P87, P88, P89, P90, P91, P92, P93, P94, P95, P96, P97, P98, P99, P100, P110, P120, P130, P140, P150, P160, P170, P180, P190, P200, P250, P300, P350, 1 year, 1.5 years, 2 years, 2.5 years, 3 years or older. While delivery to an individual in need thereof after birth is contemplated, intrauteral delivery and delivery to the mother are also contemplated.
[0047] Compositions suitable for systemic or intrathecal use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating actions of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, liquid polyethylene glycol and the like), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of a dispersion and by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal and the like. In many cases it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by use of agents delaying absorption, for example, aluminum monostearate and gelatin, and Tween family of products (e.g., Tween 20).
[0048] Sterile injectable solutions are prepared by incorporating rAAV in the required amount in the appropriate solvent with various other ingredients enumerated above, as required, followed by filter sterilization. Generally, dispersions are prepared by incorporating the sterilized active ingredient into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze drying technique that yield a powder of the active ingredient plus any additional desired ingredient from the previously sterile-filtered solution thereof.
[0049] Transduction with rAAV may also be carried out in vitro. In one embodiment, desired target cells are removed from the subject, transduced with rAAV and reintroduced into the subject. Alternatively, syngeneic or xenogeneic cells can be used where those cells will not generate an inappropriate immune response in the subject.
[0050] Suitable methods for the transduction and reintroduction of transduced cells into a subject are known in the art. In one embodiment, cells can be transduced in vitro by combining rAAV with the cells, e.g., in appropriate media, and screening for those cells harboring the DNA of interest using conventional techniques such as Southern blots and/or PCR, or by using selectable markers. Transduced cells can then be formulated into pharmaceutical compositions, and the composition introduced into the subject by various techniques, such as by injection into the spinal cord.
[0051] Transduction of cells with rAAV of the invention results in sustained expression of polypeptide. The present invention thus provides methods of administering/delivering rAAV (e.g., encoding SMN protein or MECP2 protein) of the invention to an animal or a human patient. These methods include transducing nerve and/or glial cells with one or more rAAV of the present invention.
[0052] Transduction may also be carried out with gene cassettes comprising tissue specific control elements. For example, promoters that allow expression specifically within neurons or specifically within astrocytes. Examples include neuron specific enolase and glial fibrillary acidic protein promoters. Inducible promoters under the control of an ingested drug may also be developed (e.g., rapamycin). By way of non-limiting example, it is understood that systems such as the tetracycline (TET on/off) system [see, for example, Urlinger et al., Proc. Natl. Acad. Sci. USA 97(14):7963-7968 (2000) for recent improvements to the TET system] and Ecdysone receptor regulatable system [Palli et al., Eur J. Biochem 270: 1308-1315 (2003] may be utilized to provide inducible polynucleotide expression. It will also be understood by the skilled artisan that combinations of any of the methods and materials contemplated herein may be used for treating a neurodegenerative disease.
[0053] The term “transduction” is used to refer to the administration/delivery of a polynucleotide (e.g., SMN DNA or MECP2 DNA) to a recipient cell either in vivo or in vitro, via a replication-deficient rAAV of the invention resulting in expression of a functional polypeptide (e.g., SMN or MECP2) by the recipient cell.
[0054] Thus, the invention provides methods of administering an effective dose (or doses, administered essentially simultaneously or doses given at intervals) of rAAV of the invention to a patient in need thereof.
[0055] In still another aspect, methods of the invention may be used to deliver polynucleotides to a vascular endothelial cell rather than across the BBB.
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] FIG. 1 depicts GFP expression in the gastrocnemius muscle of AAV9-GFP or PBS treated mice.
[0057] FIG. 2 depicts widespread neuron and astrocyte AAV9-GFP transduction in CNS and PNS 10-days-post-intravenous injection of P1 mice. (A-B) GFP and ChAT immunohistochemistry of cervical (A) and lumbar (B) spinal cord. (C) High-power magnification shows extensive co-localization of GFP and ChAT positive cells. (arrow indicates a GFP-positive astrocyte). (D) Neurons and astrocytes transduced in the hippocampus. (E) Pyramidal cells in the cortex were GFP positive. (F) Clusters of GFP positive astrocytes were observed throughout the brain. Scale bars (A-B) 200 μm, (C) 50 μm, (D-F) 50 μm.
[0058] FIG. 3 shows that intravenous injection of AAV9 leads to widespread neonatal spinal cord transduction. Cervical (a-c) and lumbar (e-k) spinal cord sections ten-days following facial-vein injection of 4×10 11 particles of scAAV9-CB-GFP into postnatal day-1 mice. GFP-expression (a, e, i) was predominantly restricted to lower motor neurons (a, e, i) and fibers that originated from dorsal root ganglia (a, e). GFP-positive astrocytes (i) were also observed scattered throughout the tissue sections. Lower motor neuron and astrocyte expression were confirmed by co-localization using choline acetyl transferase (ChAT) (b, f, j) and glial fibrillary acidic protein (GFAP) (c, g, k), respectively. A z-stack image (i-k) of the area within the box in h, shows the extent of motor neuron and astrocyte transduction within the lumbar spinal cord. Scale bars, 200 μm (d, h), 20 μm (l).
[0059] FIG. 4 shows that intravenous injection of AAV9 leads to widespread and long term neonatal spinal cord transduction in lumbar motor neurons. Z-series confocal microscopy showing GFP-expression in 21-day-old mice that received 4×10 11 particles of scAAV9-CB-GFP intravenous injections on postnatal day-1. Z-stack images of GFP (a), ChAT (b), GFAP (c) and merged (d) demonstrating persistent GFP-expression in motor neurons and astrocytes (d) for at least three-weeks following scAAV9-CB-GFP injection. Scale bar, 20 μm (d).
[0060] FIG. 5 depicts in situ hybridization of spinal cord sections from neonate and adult injected animals demonstrates that cells expressing GFP are transduced with scAAV9-CB-GFP. Negative control animals injected with PBS (a-b) showed no positive signal. However, antisense probes for GFP demonstrated strong positive signals for both neonate (c) and adult (e) sections analyzed. No positive signals were found for the sense control probe in neonate (d) or adult (f) spinal cord sections. Tissues were counterstained with Nuclear Fast Red for contrast while probe hybridization is in black.
[0061] FIG. 6 depicts cervical (A), thoracic (B) and lumbar (C) transverse sections from mouse spinal cord labeled for GFP and ChAT. The box in (C) denotes the location of (D-F). GFP (D), ChAT (E) and merged (F) images of transduced motor neurons in the lumbar spinal cord. In addition to motor neuron transductions, GFP positive fibers are seen in close proximity and overlapping motor neurons (D and F). Scale bars=(A-C) 200 μm and (F) 50 μm.
[0062] FIG. 7 depicts GFP (A), ChAT (B) and merged (C) images of a transverse section through lumbar spinal cord of a P10 mouse that had previously been injected at one day old with scAAV9 GFP. (D) represents a z-stack merged image of the ventral horn from (C). (E) shows that the scAAV9 vector resulted in more transduced motor neurons when compared to ssAAV9 vector in the lumbar spinal cord. Scale bars=(C) 100 μm and (D) 50 μm.
[0063] FIG. 8 depicts AAV9-GFP targeting of astrocytes in the spinal cord of adult-mice. (A-B) GFP immunohistochemistry in cervical (A) and lumbar (B) spinal cord demonstrating astrocyte transduction following tail-vein injection. (hatched-line indicates grey-white matter interface). (C) GFP and GFAP immunohistochemistry from lumbar spinal cord indicating astrocyte transduction. Scale bars (A-B) 100 μm, (C) 20 μm.
[0064] FIG. 9 shows that intravenous injection of AAV9 leads to widespread predominant astrocyte transduction in the spinal cord and brain of adult mice. GFP-expression in the cervical (a-c) and lumbar (e-g) spinal cord as well as the brain (m-o) of adult mice 7-weeks after tail vein injection of 4×10 12 particles of scAAV9-CB-GFP. In contrast to postnatal day-1 intravenous injections, adult tail vein injection resulted in almost exclusively astrocyte transduction. GFP (a,e), ChAT (b,f) and GFAP (c,g) demonstrate the abundance of GFPexpression throughout the spinal grey matter, with lack of co-localization with lower motor neurons and white matter astrocytes. Co-localization of GFP (i), excitatory amino acid transporter 2 (EAAT2) (j), and GFAP (k) confirm that transduced cells are astrocytes. Tail vein injection also resulted in primarily astrocyte transduction throughout the brain as seen in the cortex (m-n), thalamus (o) and midbrain. Neuronal GFP-expression in the brain was restricted to the hippocampus and dentate gyrus (m-n, FIG. 11 e - f ).
[0065] FIG. 10 depicts diagrams of coronal sections throughout the mouse brain corresponding to the approximate locations shown in ( FIG. 9 m - o ). The box in (a) corresponds to the location shown in ( FIG. 9 m ). The smaller box in (b) corresponds to ( FIG. 9 n ) and the larger box to ( FIG. 9 o ).
[0066] FIG. 11 depicts high-magnification of merged GFP and dapi images of brain regions following neonate (a-d) or adult (e-f) intravenous injection of scAAV9-CB-GFP. Astrocytes and neurons were easily detected in the striatum (a), hippocampus (b) and dentate gyrus (c) following postnatal day-1 intravenous injection of 4×10 11 particles of scAAV9-CB-GFP. Extensive GFP-expression within cerebellar Purkinje cells (d) was also observed. Pyramidal cells of the hippocampus (e) and granular cells of the dentate gyrus (f) were the only neuronal transduction within the brain following adult tail vein injection. In addition to astrocyte and neuronal transduction, widespread vascular transduction (f) was also seen throughout all adult brain sections examined. Scale bars, 200 μm (e); 100 μm (f), 50 μm (a-d).
[0067] FIG. 12 depicts widespread GFP-expression 21-days following intravenous injection of 4×10 11 particles of scAAV9-CB-GFP to postnatal day-1 mice. GFP localized in neurons and astrocytes throughout multiple structures of the brain as depicted in: (a) striatum (b) cingulate gyrus (c) formix and anterior commissure (d) internal capsule (e) corpus callosum (f) hippocampus and dentate gyrus (g) midbrain and (h) cerebellum. All panels show GFP and DAPI merged images. Schematic representations depicting the approximate locations of each image throughout the brain are shown in ( FIG. 13 ). Higher magnification images of select structures are available in ( FIG. 11 , 14 ). Scale bars, 200 μm (a); 50 μm (e); 100 μm (b-d,f-h).
[0068] FIG. 13 depicts diagrams of coronal sections throughout the mouse brain. corresponding to the approximate locations shown in FIG. 12( a - h ) for postnatal day-1 injected neonatal mouse brains. The box in (a) corresponds to the location of ( FIG. 12 a ). The smaller box in (b) corresponds to ( FIG. 12 b ) and the larger box to ( FIG. 12 c ). The larger box in (c) corresponds to ( FIG. 12 d ) while the smaller box in (c) represents ( FIG. 12 e ). Finally, (d-f) correspond to ( FIG. 12 f - h ) respectively.
[0069] FIG. 14 depicts co-localization of GFP positive cells with GAD67. Immunohistochemical detection of GFP (a,d,g,j) and GAD67 (b,e,h,k) expression within select regions of mouse brain 21-days following postnatal day-1 injection of 4×10 11 particles of scAAV9-CB-GFP. Merged images (c,f,i,l) show limited co-localization of GFP and GAD67 signals in the cingulate gyrus (a-c), the dentate gyrus (d-f) and the hippocampus (g-i), but numerous GFP/GAD67 Purkinje cells within the cerebellum(1). Scale bars, 100 μm (c), 50 μm (a-b,d-l).
[0070] FIG. 15 depicts gel electrophoresis and silver staining of various AAV9-CBGFP vector preparations demonstrates high purity of research grade virus utilized in studies. Shown are 2 vector batches at varying concentrations demonstrating the predominant 3 viral proteins (VP); VP1, 2, 3 as the significant components of the preparation. 1 μl, 5 μl, and 10 μl were loaded of each respective batch of virus.
[0071] FIG. 16 depicts direct injection of scAAV9-CB-GFP into the brain and demonstrates predominant neuronal transduction. Injection of virus into the striatum (a) and hippocampus (b) resulted in the familiar neuronal transduction pattern as expected. Co-labeling for GFP and GFAP demonstrate a lack of astrocyte transduction in the injected structures with significant neuronal cell transduction. Scale bars, 50 μm (a), 200 μm (b).
[0072] FIG. 17 is a schematic of scAAV9/MECP2 vector.
[0073] FIG. 18 shows that systemic injection of MECP2B null/y mice with scAAV9/MECP2 virus results in MECP2 expression in different cell types in brain. (a) Experimental paradigm. (b) MECP2 expression is expressed preferentially in brainstem of injected mice (n=3). (c) Expression of MECP2 in neurons and non neuronal cells varies with brain region (n=3). In panels b and c *P<0.05, **P<0.01 and ***P<0.001 by one way ANOVA (Newman-Keuls multiple comparison test). Data are means±s.e.m.
[0074] FIG. 19 shows MECP2 expressed from virus binds to DNA, restores normal neuronal somal size and improves survival. (f) Kaplan-Meier survival curve. (g) Observational scores. MECP2Bnull/y-scAAV9/MECP2 (n=5), MECP2Bnull/y-AAV9/Control (n=6), MECP2+/y (n=6). Data are means±s.e.m. (h) Field pixel intensities of MECP2-Cy3 immunofluorescence measured from brainstem sections of non-injected and scAAV9/MECP2-injected males (left) and females (right). n=10 fields each condition. ALU, Arbitrary Linear Unit.
[0075] FIG. 20 shows systemic delivery of scAAV9/MECP2 virus into Mecp2 Bnull/+ mice prevents progression, or reverses aberrant behaviors. (a) Experimental paradigm. Mice were analyzed five months post injection. (b) Average observational scores of Mecp2 Bnull/+ mice injected with scAAV9/MeCP2 (n=8), scAAV9/Control (n=5). Non-injected (Mecp2 +/+ ) mice (n=8). Arrow indicates time of behavioral analysis. (c) Rotorod activity on third day of test. (d) Inverted grid test. (e) Platform test. scAAV9/MeCP2 (n=8), scAAV9/Control (n=5). Mecp2 +/+ (n=8). (f) Nesting ability. scAAV9/MeCP2 (n=8), scAAV9/Control (n=5). Mecp2 +/+ (n=8). *P<0.05, **P<0.01, ***P<0.001 and ns=not significant by one way ANOVA (Newman-Keuls multiple comparison test for panel c and one way ANOVA (Dunn's multiple comparison test for panels d-f. Data are means±s.e.m.
[0076] FIG. 21 is a Kaplan-Meier survival curve showing that Mecp2 Bnull/+ mice injected with scAAV9/MECP2 do not die prematurely compared to non-injected Mecp2 +/+ mice. P>0.05 by Gehan-Breslow-Wilcoxon test.
[0077] FIG. 22 shows the sequence of the genome of the exemplary rAAV9 named “scAAV9 MECP2.” Its genome has in sequence an AAV2 ITR missing the terminal resolution site (nucleotides 662-767), an approximately 730 bp murine MECP2 promoter fragment (nucleotides 859-1597), SV40 late 19s and late 16s intron sequences (1602-1661), murine MECP2 coding sequences (nucleotides 1799-3304), a bovine growth hormone polyadenylation signal sequence (nucleotides 3388-3534) and an AAV2 ITR (nucleotides 3614-3754). The scAAV9 MECP2 genome lacks AAV rep and cap DNA, that is, there is no AAV rep or cap DNA between the ITRs of the genome.
[0078] FIG. 23 shows the sequence of the genome of the exemplary rAAV9 named “scAAV9 hMECP2.” Its genome has in sequence an AAV2 ITR missing the terminal resolution site (nucleotides 662-767), an approximately 730 bp murine MECP2 promoter fragment (nucleotides 859-1597), SV40 late 19s and late 16s intron sequences (nucleotides 1602-1661), human MECP2α coding sequences (nucleotides 1765-3261), a bovine growth hormone polyadenylation signal sequence (nucleotides 3314-3460) and an AAV2 ITR (nucleotides 3540-3680). The scAAV9 hMECP2 genome lacks AAV rep and cap DNA, that is, there is no AAV rep or cap DNA between the ITRs of the genome.
DETAILED DESCRIPTION
[0079] The present invention is illustrated by the following examples relating to a novel rAAV9 and its ability to efficiently deliver genes to the spinal cord via intravenous delivery in both neonatal animals and in adult mice. Example 1 describes experiments showing that rAAV9 can transduce and express protein in mouse skeletal muscle. Example 2 describes experiments in which the expression of the rAAV9 transgene was examined. Example 3 describes the ability of rAAV9 to transduce and express protein in lumbar motor neurons (LMNs). Example 4 describes the evaluation of vectors that do not require second-strand synthesis. Example 5 describes experiments focused on examining whether rAAV9 vectors were enhanced for retrograde transport to target dorsal root ganglion (DRG) and LMNs or could easily pass the blood-brain-barrier (BBB) in neonates. Example 6 describes the evaluation of optimal delivery of rAAV9 expressing SMN for postnatal gene replacement in a mouse model of Type 2 SMA for function and survival. Example 7 describes the examination of the brains of mice following postnatal day-one intravenous injection of scAAV9-CBGFP. Example 8 describes the investigation of whether astrocyte transduction is related to vector purity or delivery route. Example 9 describes administration of scAAV9-GFP in a nonhuman primate. Example 10 describes experiments demonstrating that self complementary rAAV9 bearing MECP2 cDNA under control of a fragment of its own promoter (scAAV9/MECP2), was capable of significantly stabilizing or reversing disease phenotypes when administered systemically into female RTT mouse models.
Example 1
[0080] The ability of AAV9 to target and express protein in skeletal muscle was evaluated in an in vivo model system.
[0081] Intravenous administration of 1×10 11 particles of scAAV9-GFP was performed in a total volume of 50 μl to postnatal day 1 mice and the extent of muscle transduction was evaluated. The rAAV GFP genome included in sequence an AAV2 ITR, the chicken β-actin promoter with a cytomegalovirus enhancer, an SV40 intron, the GFP DNA, a polyadenylation signal sequence from bovine growth hormone and another AAV2 ITR. The ability of the AAV9 vectors to transduce skeletal muscle was evaluated using a GFP expressing vector. AAV9-GFP expressed at high levels in the skeletal muscles that were analyzed. Ten days following injections, animals were euthanized and gastrocnemius muscles were rapidly isolated, frozen using liquid nitrogen chilled isopentane, and sectioned on a cryostat at 15 μm. Analysis of muscle sections using a Zeiss Axiovert microscope equipped with GFP fluorescence demonstrated that AAV9-GFP expressed at very high levels, with over 90% of the analyzed gastrocnemius muscle transduced ( FIG. 1 ). No GFP expression was detected in PBS control treated animals ( FIG. 1 ). These results showed that AAV9 was effective at targeting and expressing in skeletal muscles.
Example 2
[0082] Transgene expression following intravenous injection in neonatal animals prior to the closure of the BBB and in adult animals was examined.
[0083] Mice used were C57B1/6 littermates. The mother (singly housed) of each litter to be injected was removed from the cage. The postnatal day 1 (P1) pups were rested on a bed of ice for anesthetization. For neonate injections, a light microscope was used to visualize the temporal vein (located just anterior to the ear). Vector solution was drawn into a 3/10 cc 30 gauge insulin syringe. The needle was inserted into the vein and the plunger was manually depressed. Injections were in a total volume of 1000 of a phosphate buffered saline (PBS) and virus solution. A total of 1×10 11 DNase resistant particles of scAAV9 CB GFP (Virapur LLC, San Diego) were injected. One-day-old wild-type mice received temporal vein injections of 1×10 11 particles of a self-complementary (sc) AAV9 vector [McCarty et al., Gene therapy, 10: 2112-2118 (2003)] that expressed green fluorescent protein (GFP) under control of the chicken-β-actin hybrid promoter (CB). A correct injection was verified by noting blanching of the vein. After the injection pups were returned to their cage. When the entire litter was injected, the pups were rubbed with bedding to prevent rejection by the mother. The mother was then reintroduced to the cage. Neonate animals were sacrificed ten days post injection, spinal cords and brains were extracted, rinsed in PBS, then immersion fixed in a 4% paraformaldehyde solution.
[0084] Adult tail vein injections were performed on ˜70 day old C57B1/6 mice. Mice were placed in restraint that positioned the mouse tail in a lighted, heated groove. The tail was swabbed with alcohol then injected intravenously with a 1000 viral solution containing a mixture of PBS and 5×10 11 DNase resistant particles of scAAV9 CB GFP. After the injection, animals were returned to their cages. Two weeks post injection, animals were anesthetized then transcardially perfused first with 0.9% saline then 4% paraformaldehyde. Brains and spinal cords were harvested and immersion fixed in 4% paraformaldehyde for an additional 24-48 hours.
[0085] Neonate and adult brains were transferred from paraformaldehyde to a 30% sucrose solution for cryoprotection. The brains were mounted onto a sliding microtome with Tissue-Tek O.C.T. compound (Sakura Finetek USA, Torrance, Calif.) and frozen with dry ice. Forty micron thick sections were divided into 5 series for histological analysis. Tissues for immediate processing were placed in 0.01 M PBS in vials. Those for storage were placed in antifreeze solution and transferred to −20° C. Spinal cords were cut into blocks of tissue 5-6 mm in length, then cut into 40 micron thick transverse sections on a vibratome. Serial sections were kept in a 96 well plate that contained 4% paraformaldehyde and were stored at 4° C.
[0086] Brains and spinal cords were both stained as floating sections. Brains were stained in a 12-well dish, and spinal cords sections were stained in a 96-well plate to maintain their rostral-caudal sequence. Tissues were washed three times for 5 minutes each in PBS, then blocked in a solution containing 10% donkey serum and 1% Triton X-100 for two hours at room temperature. After blocking, antibodies were diluted in the blocking solution at 1:500. The primary antibodies used were as follows: goat anti-ChAT and mouse anti-NeuN (Chemicon), rabbit anti-GFP (Invitrogen) and guinea pig anti-GFAP (Advanced Immunochemical). Tissues were incubated in primary antibody at 4° C. for 48-72 hours then washed three times with PBS. After washing, tissues were incubated for 2 hours at room temperature in the appropriate secondary antibodies (1:125 Jackson Immunoresearch) with DAPI. Tissues were then washed three times with PBS, mounted onto slides then coverslipped. All images were captured on a Zeiss laser-scanning confocal microscope.
[0087] Spinal cords had remarkable GFP expression throughout all levels with robust GFP expression in fibers that ascended in the dorsal columns and fibers that innervated the spinal gray matter, indicating dorsal root ganglia (DRG) transduction. GFP positive cells were also found in the ventral region of the spinal cord where lower motor neurons reside ( FIG. 2A-B ). Labeling of choline acetyl transferase (ChAT) positive cells with GFP demonstrated a large number of ChAT positive cells expressing GFP throughout all cervical and lumbar sections examined, indicating widespread LMN transduction ( FIG. 2C ). Approximately 56% of ChAT positive cells strongly expressed GFP in sections analyzed of the lumbar spinal cord (598 GFP+/1058 ChAT+, n=4) (Table 1, below). This is the highest proportion of LMNs transduced by a single injection of AAV reported. Stereology for total number of neurons in a given area and total number of GFP+ cells was performed on a Nikon E800 fluorescent microscope with computer-assisted microscopy and image analysis using StereoInvestigator software (MicroBrightField, Inc., Williston, Vt.) with the optical dissector principle to avoid oversampling errors and the Cavalieri estimation for volumetric measurements. Coronal 40 μm sections, 240 μm apart covering the regions of interest in its rostro-caudal extension was evaluated. The entire dentate gyrus, caudal retrosplenial/cingulate cortex; containing the most caudal extent of the dentate gyrus; extending medially to the subiculum and laterally to the occipital cortex, and the purkinje cell layer was sampled using ˜15-25 optical dissectors in each case. Fluorescent microscopy using a 60× objective for NeuN and GFP were utilized and cells within the optical dissector were counted on a computer screen. Neuronal density and positive GFP density were calculated by multiplying the total volume to estimate the percent of neuronal transduction in each given area as previously described [Kempermann et al., Proceedings of the National Academy of Sciences of the United States of America 94: 10409-10414 (1997)].
[0088] For motor neuron quantification, serial 40 μm thick lumbar spinal cord sections, each separated by 480 μm, were labeled as described for GFP and ChAT expression. Stained sections were serially mounted on slides from rostral to caudal, then coverslipped. Sections were evaluated using confocal microscopy (Zeiss) with a 40× objective and simultaneous FITC and Cy3 filters. FITC was visualized through a 505-530 nm band pass filter to avoid contaminating the Cy3 channel. The total number of ChAT positive cells found in the ventral horns with defined soma was tallied by careful examination through the entire z-extent of the section. GFP labeled cells were quantified in the same manner, while checking for co-localization with ChAT. The total number of cells counted per animal ranged from approximately 150-366 cells per animal. For astrocyte quantification, as with motor neurons, serial sections were stained for GFP, GFAP and EAAT2, then mounted. Using confocal microscopy with a 63× objective and simultaneous FITC and Cy5 filters, random fields in the ventral horns of lumbar spinal cord sections from tail vein injected animals were selected. The total numbers of GFP and GFAP positive cells were counted from a minimum of at least 24-fields per animal while focusing through the entire z extent of the section.
[0089] In addition to widespread DRG and motor neuron transduction, GFP-positive glial cells were observed throughout the spinal gray matter ( FIG. 2C ; arrow). The brains were next examined following P1 intravenous injection of AAV9-CB-GFP and revealed extensive GFP expression in all regions analyzed, including the hippocampus ( FIG. 2D ), cortex ( FIG. 2E ), striatum, thalamus, hypothalamus and choroid plexus, with predominant neuronal transduction. However, transduced astrocytes were also found in all regions of the brain examined ( FIG. 2F ).
[0090] The remarkable pattern of GFP expression observed following P1 administration suggests two independent modes of viral entry into the central nervous system (CNS). Due to the ubiquitous GFP expression throughout the brain, the virus likely crossed the developing BBB. However the GFP expression pattern in the neonate spinal cord is defined with respect to the specific DRG and LMN transduction. The DRG and the LMN have projections into the periphery which suggests retrograde transport may be the mechanism of transduction. In support of retrograde transport as the method of spinal cord neuronal transduction, there were no GFP positive interneurons observed in any section examined. Alternatively, the virus may have a LMN tropism after crossing the BBB, but this appears unlikely as ChAT positive cells still migrating from the central canal to the ventral horn were largely untransduced ( FIG. 2A-B ).
[0000]
TABLE 1
Neonate
GFP (mean +/− s.e.m.)
NeuN (mean +/− s.e.m.)
% (mean +/− s.e.m.)
Brain
Retrosplenial/Cingulate
142,658.30 +/− 11124.71
762,104.30 +/− 38397.81
18.84 +/− 1.93
Dentate Gyrus
42,304.33 +/− 15613.33
278,043.70 +/− 11383.56
14.82 +/− 4.89
Purkinje cells
52,720.33 +/− 1951.33
73,814.86 +/− 5220.80
71.88 +/− 3.65
GFP (mean +/− s.e.m.)
ChAT (mean +/− s.e.m.)
% (mean +/− s.e.m.)
Lumbar
10 days post injection
149.5 +/− 31.65
264.5 +/− 53.72
56.18 +/− 1.95
spinal cord
21 days post injection
83.33 +/− 16.33
140.0 +/− 31.76
60.79 +/− 2.96
Adult
GFP (mean +/− s.e.m.)
GFAP (mean +/− s.e.m.)
% (mean +/− s.e.m.)
Lumbar
% GFP colabeled w/GFAP
48.00 +/− 10.12
43.00 +/− 7.00
91.44 +/− 4.82
spinal cord
% GFAP+ transduced
41.33 +/− 5.55
64.33 +/− 8.67
64.23 +/− 0.96
(grey matter)
[0091] Additional experiments were done on one-day-old wild-type mice where they were administered temporal vein injections of 4×10 11 particles of a self-complementary (sc) AAV9 vector [McCarty et al., Gene therapy 10: 2112-2118 (2003)] that expressed green fluorescent protein (GFP) under control of the chicken-β-actin hybrid promoter (CB).
[0092] Histological processing was performed as above. Brains and spinal cords were both stained as floating sections. Brains were stained in a 12-well dish, and spinal cords sections were stained in a 96-well plate to maintain their rostral-caudal sequence. Tissues were washed three-times for 5-minutes each in PBS, then blocked in a solution containing 10% donkey serum and 1% Triton X-100 for two hours at room temperature. After blocking, antibodies were diluted in the blocking solution at 1:500. The primary antibodies used were as follows: goat anti-ChAT and mouse anti-NeuN (Millipore, Billerica, Mass.), rabbit anti-GFP (Invitrogen, Carlsbad, Calif.), guinea pig anti-GFAP (Advanced Immunochemical, Long Beach, Calif.) and goat anti-GAD67 (Millipore, Billerica, Mass.). Tissues were incubated in primary antibody at 4° C. for 48-72 hours then washed three times with PBS. After washing, tissues were incubated for 2 hours at room temperature in the appropriate secondary antibodies (1:125 Jackson Immunoresearch, Westgrove, Pa.) with DAPI. Tissues were then washed three times with PBS, mounted onto slides then coverslipped. All images were captured on a Zeiss-laser-scanning confocal microscope.
[0093] Animals were sacrificed 10-or 21-days post-injection, and brains and spinal cords were evaluated for transgene expression. Robust GFP-expression was found in heart and skeletal muscles as expected. Strikingly, spinal cords had remarkable GFP-expression throughout all levels, with robust GFP-expression in fibers that ascended in the dorsal columns and fibers that innervated the spinal grey matter, indicating dorsal root ganglia (DRG) transduction. GFP-positive cells were also found in the ventral region of the spinal cord where lower motor neurons reside ( FIGS. 3 a and e ). Co-labeling for choline acetyl transferase (ChAT) and GFP-expression within the spinal cord demonstrated a large number of ChAT positive cells expressing GFP throughout all cervical and lumbar sections examined, indicating widespread LMN transduction ( FIG. 4 ). Approximately 56% of ChAT positive cells strongly expressed GFP in sections analyzed of the lumbar spinal cord of 10 day-old animals and ˜61% of 21 day-old animals, demonstrating early and persistent transgene expression in lower motor neurons (Table 1). Similar numbers of LMN expression were seen in cervical and thoracic regions of the spinal cord. This is the highest proportion of LMNs transduced by a single injection of AAV reported. In addition to widespread DRG and motor neuron transduction, we observed GFP-positive glial cells throughout the spinal grey matter, indicating that AAV9 could express in astrocytes with the CB promoter. The remarkable pattern of GFP-expression observed following postnatal day-one administration suggests two independent modes of viral entry into the CNS. Due to the ubiquitous GFP-expression throughout the brain, the virus likely crossed the developing BBB. However the GFP-expression pattern in the neonate spinal cord is defined with respect to the specific DRG and LMN transduction. The DRG and the LMN have projections into the periphery which suggests retrograde transport may be the mechanism of transduction. In support of retrograde transport as the method of spinal cord neuronal transduction, there were no GFP-positive interneurons observed in any section examined. Alternatively, the virus may have a LMN tropism after crossing the BBB, but this appears unlikely as ChAT positive cells still migrating from the central canal to the ventral horn were largely untransduced.
[0094] In situ hybridization confirmed that viral transcription, and not protein uptake, was responsible for the previously unseen transduction pattern ( FIG. 5 ).
Example 3
[0095] The ability of AAV9 to transduce and express protein in LMN was evaluated.
[0096] LMN transduction in the lumbar ventral horn was evaluated following intravenous administration of 1×10 11 particles of ss or scAAV9 GFP to postnatal day 1 mice in an effort to effectively deliver a transgene to spinal cord motor neurons. Both single-stranded and self-complementary AAV9-GFP vectors were produced via transient transfection production methods and were purified two times on CsCl gradients. The AAV9 GFP genomes are identical with the exception that scAAV genomes have a mutation in one ITR to direct packaging of specifically self-complementary virus. The single stranded AAV constructs do not contain the ITR mutation and therefore package predominantly single stranded virus. Viral preps were titered simultaneously using TAQMAN Quantitative PCR. P1 mice (n=5/group) were placed on an ice-cold plates to anesthetize and virus was delivered using 0.3 cc insulin syringes with 31 gauge needles that were inserted into the superficial facial vein. Virus was delivered in a volume of 50 μl. Animals recovered quickly after gene delivery with no adverse events noted. Animals were injected with a xylazine/ketamine mixture and were decapitated 10-days following injection and spinal cords were harvested then post-fixed in 4% paraformaldehyde, sectioned using a Vibratome and immunohistochemistry was performed using co-labeling for ChAT and GFP. Analysis of GFP expression was performed using a Zeiss Confocal Microscope.
[0097] Intravenous injection of single stranded AAV9-GFP resulted in widespread DRG transduction as evidenced by GFP positive fibers innervating the spinal grey matter and ascending in the dorsal columns ( FIG. 6A-C ). Numerous sections showed strong GFP staining in motor neurons as assessed by co-labeling GFP with Choline acetyltransferase (ChAT) ( FIG. 3E-F ). Counting the total number of motor neurons in treated animals demonstrated approximately 8% of total motor neurons residing in the lumbar region of the spinal cord were transduced. This finding was remarkable given that motor neuron transduction has typically been very low (less than 1% of total motor neurons), particularly by remote delivery approaches such as retrograde transport.
Example 4
[0098] Self-complementary scAAV9 vectors that do not require second-strand synthesis (a rate limiting step of AAV vectors) which would allow for greater efficiencies of expression in motor neurons, were evaluated.
[0099] Viral particles were prepared as in Example 3. Intravenous injections into the facial vein of P1 pups were performed as described above and the animals as described above 10 days post-injection. As with ssAAV9 injections significant transduction of DRG was observed throughout the spinal cord. Remarkably, significant motor neuron transduction in treated animals was found in the two areas of the spinal cord that were evaluated including the cervical and lumbar spinal cord. Quantification of GFP+/ChAT+ double labeled cells expressed as a percentage of total ChAT+ cells within the lumbar spinal cord showed that ˜45% of LMN were transduced by dsAAV9 compared with ˜8% of ssAAV9 ( FIG. 7E ). Indeed, some regions of the spinal cord showed >90% motor neuron transduction ( FIG. 7D ) and other regions may have greater amounts of GFP positive motor neurons, given that dim GFP positive cells were not counted due to a conservative GFP positive scoring used in the counting. This amount of LMN transduction following a single injection of AAV has not previously been reported.
Example 5
[0100] Further investigation focused on whether AAV9 vectors were enhanced for retrograde transport to target DRG and LMNs or could easily pass the BBB in neonates.
[0101] The pattern of transduction was examined to determine if it was consistent between neonates and adult animals. Adult mice were injected via tail vein delivery using 4×10 11 to 5×10 11 particles of scAAV9-CB-GFP. A strikingly different transduction pattern was seen in adult treated animals compared to the treated neonates. Most noticeably, there was an absence of GFP positive DRG fibers and a marked decrease in LMN transduction in all cervical and lumbar spinal cord sections examined. GFP-positive astrocytes were easily observed throughout the entire dorsal-ventral extent of the grey matter in all regions of the spinal cord ( FIG. 8 a - b and FIG. 9 a - c and e - g ) with the greatest GFP-expression levels found in the higher dosed animals. Co-labeling of GFP-positive cells with astroglial markers excitatory amino acid transporter 2 (EAAT2) and glial fibrillary acidic protein (GFAP) ( FIG. 8C ) demonstrated that approximately 90% of the GFP-positive cells were astrocytes. Counts of total astrocytes in the lumbar region of the spinal cord by z-series collected confocal microscopy showed over 64% of total astrocytes were positive for GFP ( FIG. 9 i - k and Table 1). FIG. 10 depicts diagrams of coronal sections throughout the mouse brain corresponding to the approximate locations shown in ( FIG. 9 m - o ). The box in (a) corresponds to the location shown in ( FIG. 9 m ). The smaller box in (b) corresponds to ( FIG. 9 n ) and the larger box to ( FIG. 9 o ).
[0102] Viral transcription was again confirmed in adult tissues with in situ hybridization ( FIG. 5 ). Furthermore, whereas neonate intravenous injection resulted in indiscriminate astrocyte and neuronal transduction throughout the brain, adult tail-vein injections produced isolated and localized neuronal expression only in the hippocampus and dentate gyrus ( FIG. 9 m - n and FIG. 11 e - f ) in both low and high dose animals. Low-dose animals had isolated patches of transduced astrocytes scattered throughout the entire brain. Of significance, high-dose animals had extensive astrocyte and vascular transduction throughout the entire brain ( FIG. 9 m - o and FIG. 11 e - f ) that persisted for at least seven-weeks post-injection (n=5), suggesting a dose-response of transduction, without regional specificity.
[0103] To date, efficient glial transduction has not been reported for any AAV serotype indicating that AAV9 has a unique transduction property in the CNS following intravenous delivery. An occasional neuron transduced in the spinal cord, although these events were scarce in adult animals. Furthermore, whereas neonate intravenous injection resulted in indiscriminate transduction throughout the brain, adult tail vein injections produced isolated and localized neuronal expression in the hippocampus with isolated patches of glial transduction scattered throughout the entire brain. The scarcity of LMN and DRG transduction seen in the adult paradigm suggests there is a developmental period in which access by circulating virus to these cell populations becomes restricted. Assuming a dependence on retrograde transport for DRG and LMN transduction following intravenous injection, Schwann cell or synapse maturation may be an important determinant of successful rAAV9 LMN and DRG transduction.
[0104] The results demonstrate the striking capacity of AAV9 to efficiently target neurons, and in particular motor neurons in the neonate and astrocytes in the adult following intravenous delivery. A simple intravenous injection of AAV9 as described here is clinically relevant for both SMA and ALS. In the context of SMA, data suggests that increased expression of survival motor neuron (SMN) gene in LMNs may hold therapeutic benefit [Azzouz et al., The Journal of Clinical Investigation, 114: 1726-1731 (2004) and Baughan et al., Mol. Ther. 14: 54-62 (2006)]. The importance of the results presented here is that with a single injection SMN expression levels are effectively restored in LMN. Additionally, given the robust neuronal populations transduced throughout the CNS in neonatal animals, this approach also allows for overexpressing or inhibiting genes using siRNA [see, for example, Siegel et al., PLoS Biology, 2: e419 (2004)]. The results also demonstrated efficient targeting of astrocytes in adult-treated animals and this finding is relevant for treating ALS where the non-cell autonomous nature of disease progression has recently been discovered and astrocytes have been specifically linked to disease progression [Yamanaka et al., Nature Neuroscience, 11: 251-253 (2008)]. Targeting these cells with trophic factors or to circumvent aberrant glial activity is useful in treating ALS [Dodge et al., Mol. Ther., 16(6):1056-64 (2008)].
Example 6
[0105] Optimal delivery of AAV9 expressing SMN is described for postnatal gene replacement in a mouse model of Type 2 SMA.
[0106] Studies of the SMA patient population and the various SMA animal models have established a positive correlation between amounts of full-length SMN protein produced and lessened disease severity. Histone deacetylase (HDAC) inhibitors and small molecules are currently being investigated for their ability to increase transcript production or alter exon 7 inclusion from the remaining SMN2 gene [Avila et al., J. Clin. Invest., 117(3):659-71 (2007) and Chang et al., Proc. Natl. Acad. Sci. USA, 98(17):9808-9813 (2001)]. Data presented herein demonstrates that a large percentage of LMNs can be targeted with a scAAV9 vector, and SMN gene replacement to treat SMA animals is therefore contemplated.
[0107] Mendelian inheritance predicts 25% of the pups in the litters of SMA breeders to be affected. Affected SMA mice are produced by interbreeding SMN2 +/+ , SMNΔ7 +/+ , Smn +/− mice. Breeders are maintained as homozygotes for both transgenes and heterzygotes for the knockout allele. Mice were genotyped by PCR following extraction of total genomic DNA from a tail snip (see below). One primer set was used to confirm the presence of the knockout allele while the second primer set detected an intact mouse Smn allele. Animals were treated with either scAAV9 SMN or scAAV9 GFP as controls.
[0108] SMA parent mice (Smn +/− , SMN2 +/+ , SMNΔ7 +/+ ) were time mated [Monani et al., Human Molecular Genetics 9: 333-339 (2000)]. Cages were monitored 18-21 days after visualization of a vaginal plug for the presence of litters. Once litters were delivered, the mother was separated out, pups were given tattoos for identification and tail samples were collected. Tail samples were incubated in lysis solution (25 mM NaOH, 0.2 mM EDTA) at 90° C. for one hour. After incubation, tubes were placed on ice for ten minutes and then received an equal volume of neutralization solution (40 mM Tris pH5). After the neutralization buffer, the extracted genomic DNA was added to two different PCR reactions for the mouse Smn allele (Forward 1: 5′-TCCAGCTCCGGGATATTGGGATTG (SEQ ID NO: 2), Reverse 1: 5′-AGGTCCCACCACCTAAGAAAGCC (SEQ ID NO: 3), Forward 2: 5′-GTGTCTGGGCTGTAGGCATTGC (SEQ ID NO: 4), Reverse 2: 5′-GCTGTGCCTTTTGGCTTATCTG (SEQ ID NO: 5)) and one reaction for the mouse Smn knockout allele (Forward: 5′-GCCTGCGATGTCGGTTTCTGTGAGG (SEQ ID NO: 6), Reverse: 5′-CCAGCGCGGATCGGTCAGACG (SEQ ID NO: 7)). After analysis of the genotyping PCR, litters were culled to three animals. Affected animals (Smn −/− , SMN2 +/+ , SMNΔ7 +/+ ) were injected as previously described with 5×10 11 particles of self complementary AAV9 SMN or GFP [Foust et al., Nat Biotechnol 27: 59-65 (2009)].
[0109] AAV9 was produced by transient transfection procedures using a double stranded AAV2-ITR based CB-GFP vector, with a plasmid encoding Rep2Cap9 sequence as previously described [Gao et al., Journal of Virology 78: 6381-6388 (2004)] along with an adenoviral helper plasmid; pHelper (Stratagene, La Jolla, Calif.) in 293 cells. The serotype 9 sequence was verified by sequencing and was identical to that previously described [Gao et al., Journal of Virology 78: 6381-6388 (2004)]. Virus was purified by two cesium chloride density gradient purification steps, dialyzed against phosphate-buffered-saline (PBS) and formulated with 0.001% Pluronic-F68 to prevent virus aggregation and stored at 4° C. All vector preparations were titered by quantitative-PCR using Taq-Man technology. Purity of vectors was assessed by 4-12% SDS-Acrylamide gel electrophoresis and silver staining (Invitrogen, Carlsbad, Calif.).
[0110] To determine transduction levels in SMA mice (SMN2 +/+ ; SMNΔ7 +/+ ; Smn −/− ), 5×10 11 genomes of scAAV9-GFP or —SMN (n=4 per group) under control of the chicken-β-actin hybrid promoter were injected into the facial vein at P1. Forty-two ±2% of lumbar spinal motoneurons were found to express GFP 10 days post injection. The levels of SMN in the brain, spinal cord and muscle in scAAV9-SMN-treated animals are shown in. SMN levels were increased in brain, spinal cord and muscle in treated animals, but were still below controls (SMN2 +/+ ; SMNΔ7 +/+ ; Smn +/+ ) in neural tissue. Spinal cord immunohistochemistry demonstrated expression of SMN within choline acetyl transferase (ChAT) positive cells after scAAV9-SMN injection.
[0111] Pups were weighed daily and tested for righting reflex every other day from P5-P13. Righting reflex is analyzed by placing animals on a flat surface on their sides and timing 30 seconds to evaluate if the animals return to a upright position [Butchbach et al., Neurobiology of Disease 27: 207-219 (2007)]. Every five days between P15 and P30, animals were tested in an open field analysis (San Diego Instruments, San Diego, Calif.). Animals were given several minutes within the testing chamber prior to the beginning of testing then activity was monitored for five minutes. Beam breaks were recorded in the X, Y and Z planes, averaged across groups at each time point and then graphed.
[0112] Whether scAAV9-SMN treatment of SMA animals improved motor function was then evaluated. SMA animals treated with scAAV9-SMN or -GFP were evaluated for the ability of the animals to right themselves compared to control and untreated animals (n=10 per group). Control animals were found to right themselves quickly, whereas the SMN- and GFP-treated SMA animals showed difficulty at P5. By P13, however, 90% of SMN treated animals could right themselves compared to 20% of GFP-treated controls and 0% of untreated SMA animals, demonstrating that SMN-treated animals improved. Evaluating animals at P18 showed SMN-treated animals were larger than GFP-treated but smaller than controls. Locomotive ability of the SMN-treated animals were nearly identical to controls as assayed by x, y and z plane beam breaks (open field testing) and wheel running. Age-matched untreated SMA animals were not available as controls for open field or running wheel analysis due to their short lifespan.
[0113] Survival in SMN-treated SMA animals (n=11) compared to GFP-treated SMA animals (n=11) was then evaluated using Kaplan Meier survival analysis. No GFP-treated control animals survived past P22, with a median lifespan of 15.5 days. The body weight in treated SMN- or GFP-treated animals compared to wild-type littermates was analyzed. The GFP-treated animal's weight peaked at P10 and then precipitously declined until death. In contrast, SMN-treated animals showed a steady weight gain to approximately P40, where the weight stabilized at 17 grams, half of the weight of controls. No deaths occurred in the SMN-treated group until P97. Furthermore, this death appeared to be unrelated to SMA. The mouse died after trimming of long extensor teeth. Four animals (P90-99) were euthanized for electrophysiology of neuromuscular junctions (NMJ). The remaining six animals remain alive, surpassing 250 days of age.
[0114] For electrophysiology analysis, a recording chamber was continuously perfused with Ringer's solution containing the following (in mmol/l): 118 NaCl, 3.5 KCl, 2 CaCl 2 , 0.7 MgSO 4 , 26.2 NaHCO 3 , 1.7 NaH 2 PO 4 , and 5.5 glucose, pH 7.3-7.4 (20-22° C., equilibrated with 95% O 2 and 5% CO 2 ). Endplate recordings were performed as follows. After dissection, the tibialis anterior muscle was partially bisected and folded apart to flatten the muscle. After pinning, muscle strips were stained with 10 μM 4-Di-2ASP [4-(4-diethylaminostyryl)-Nmethylpyridinium iodide] (Molecular Probes) and imaged with an upright epifluorescence microscope. At this concentration, 4-Di-2ASP staining enabled visualization of surface nerve terminals as well as individual surface muscle fibers. All of the endplates were imaged and impaled within 100 μm. Two-electrode voltage clamp were used to measure endplate current (EPC) and miniature EPC (MEPC) amplitude. Muscle fibers were crushed away from the endplate band and voltage clamped to −45 mV to avoid movement after nerve stimulation.
[0115] To determine whether the reduction in endplate currents (EPCs) was corrected with scAAV9-SMN, EPCs were recorded from the tibialis anterior (TA) muscle [Wang et al., J Neurosci 24, 10687-10692 (2004)]. P9-10 animals were evaluated to ensure the presence of the reported abnormalities within our mice. Control mice had an EPC amplitude of 19.1±0.8 nA versus 6.4±0.8 nA in untreated SMA animals (p=0.001) confirming published results [Kong et al., J Neurosci 29, 842-851 (2009)]. Interestingly, P10 scAAV9-SMN-treated SMA animals had a significant improvement (8.8±0.8 vs. 6.4±0.8 nA, p<0.05) over age-matched untreated SMA animals. Gene therapy treatment, however, had not restored normal EPC at P10 (19.1±0.8 vs. 8.8±0.8 nA, p=0.001). At P90-99, there was no difference in EPC amplitude between controls and SMA mice that had been treated with scAAV-SMN. Thus, treatment with scAAV9-SMN fully corrected the reduction in synaptic current. Importantly, P90-99 age-matched untreated SMA animals were not available as controls due to their short lifespan.
[0116] The number of synaptic vesicles released following nerve stimulation (quantal content) and the amplitude of the muscle response to the transmitter released from a single vesicle (quantal amplitude) determine the amplitude of EPCs. Untreated SMA mice have a reduction in EPC due primarily to reduced quantal content [Kong et al., J Neurosci 29, 842-851 (2009)]. In our P9-10 cohort, untreated SMA animals had a reduced quantal content when compared with wild-type controls (5.7±0.6 vs. 12.8±0.6, p<0.05), but scAAV9-SMN treated animals were again improved over the untreated animals (9.5±0.6 vs. 5.7±0.6, p<0.05), but not to the level of wild-type animals (9.5±0.6 vs. 12.8±0.6, p<0.05). At P90-99, when quantal content was measured in treated SMA mice, a mild reduction was present (control=61.3±3.5, SMA-treated=50.3±2.6, p<0.05), but was compensated for by a statistically significant increase in quantal amplitude (control=1.39±0.06, SMA treated=1.74±0.08, p<0.05). Quantal amplitudes in young animals had no significant differences (control=1.6±0.1, untreated SMA=1.3±0.1, treated SMA=1.1±0.1 nA, p=0.28).
[0117] The reduction in vesicle release in untreated SMA mice was due to a decrease in probability of vesicle release, demonstrated by increased facilitation of EPCs during repetitive stimulation [Kong et al., J Neurosci 29: 842-851 (2009)]. Both control and treated SMA EPCs were reduced by close to 20% by the 10th pulse of a 50 Hz train of stimuli (22±3% reduction in control vs 19±1% reduction in treated SMA, p=0.36). This demonstrates that the reduction in probability of release was corrected by replacement of SMN. During electrophysiologic recording, no evidence of denervation was noted. Furthermore, all adult NMJs analyzed showed normal morphology and full maturity. P9-10 transverse abdominis immunohistochemistry showed the typical neurofilament accumulation in untreated SMA NMJs[Kong et al., J Neurosci 29: 842-851 (2009)], whereas treated SMA NMJs showed a marked reduction in neurofilament accumulation.
[0118] A recent study using an HDAC inhibitor to extend survival of SMA mice reported necrosis of the extremities and internal tissues [Narver et al., Ann Neurol 64: 465-470 (2008)]. In the studies described herein, mice developed necrotic pinna between P45-70. Pathological examination of the pinna noted vascular necrosis, but necrosis was not found elsewhere.
[0119] To explore the therapeutic window in SMA mice, systemic scAAV9-GFP injections were performed at varying postnatal time points to evaluate the pattern of transduction of motor neurons and astrocytes. scAAV9-GFP systemic injections in mice on P2, P5 or P10 showed distinct differences in the spinal cord. There was a shift from neuronal transduction in P2-treated animals toward predominantly glial transduction in older, P10 animals, consistent with previous studies and knowledge of the developing blood-brain barrier in mice [Foust et al., Nat. Biotechnol. 27: 59-65 (2009); Saunders et al., Nat. Biotechnol. 27: 804-805, author reply 805 (2009)].
[0120] To determine the therapeutic effect of SMN delivery at these various time points, small cohorts of SMA-affected mice were injected with scAAV9-SMN on P2, P5 and P10 and evaluated for changes in survival and body weight. P2-injected animals were rescued and indistinguishable from animals injected with scAAV9-SMN on P1. However, P5-injected animals showed a more modest increase in survival of approximately 15 days, whereas P10-injected animals were indistinguishable from GFP-injected SMA pups. These findings support previous studies demonstrating the importance of increasing SMN levels in neurons of SMA mice [Gavrilina et al., Hum. Mol. Genet. 17: 1063-1075 (2008)]. Furthermore, these results suggest a period during development in which intravenous injection of scAAV9 can target neurons in sufficient numbers for benefit in SMA.
[0121] The above results demonstrate robust, postnatal rescue of SMA mice with correction of motor function, neuromuscular electrophysiology, and increased survival following a one-time gene delivery of SMN. Intravenous scAAV9 treats neurons, muscle and vascular endothelium. Vascular delivery of scAAV9 SMN in the mouse was safe, and well tolerated.
Example 7
[0122] The brains of mice were examined following postnatal day-one intravenous injection of scAAV9-CBGFP and extensive GFP-expression was found in all regions analyzed, including the striatum, cortex, anterior commisure, internal capsule, corpus callosum, hippocampus and dentate gyrus, midbrain and cerebellum ( FIG. 12 a - h , respectively, FIG. 11 ). GFP-positive cells included both neurons and astrocytes throughout the brain. To further characterize the transduced neurons, brains were co-labeled for GFP and GAD67, a GABAergic marker. FIG. 13 depicts diagrams of coronal sections throughout the mouse brain corresponding to the approximate locations shown in FIG. 12 a - h for postnatal day-1 injected neonatal mouse brains. The box in ( 13 a ) corresponds to the location of ( FIG. 12 a ). The smaller box in ( 13 b ) corresponds to ( FIG. 12 b ) and the larger box to ( FIG. 12 c ). The larger box in ( 13 c ) corresponds to ( FIG. 12 d ) while the smaller box in ( 13 c ) represents ( FIG. 12 e ). Finally, ( 13 d - f ) correspond to ( FIG. 12 f - h ) respectively.
[0123] The cortex, hippocampus and dentate had very little colocalization between GFP and GAD67 labeled cells ( FIG. 14 a - i ), while Purkinje cells in the cerebellum were extensively co-labeled ( FIG. 14 j - l ). Finally, unbiased-estimated stereological quantification of transduction showed that 18.8+/−1.9% within the retrosplenial/cingulate cortex, 14.8+/−4.8% within the dentate gyrus and 71.8+/−3.65% within the Purkinje layer of total neurons were transduced following a one-time administration of virus (Table 1).
Example 8
[0124] Efficient astrocyte transduction by an AAV8-, but not an AAV9-vector, following direct brain injection has been previously reported. Astrocyte transduction, however, was suggested to be related to viral purification [Klein et al., Mol Ther 16: 89-96 (2008)]. To investigate whether AAV9 astrocyte transduction was related to vector purity or delivery route, multiple AAV9 preparations were evaluated for vector purity by silver-stain and 8×10 10 particles of the same scAAV9-CB-GFP vector preparations from the intravenous experiments were injected into the striatum and dentate gyrus of adult mice. Silver-staining showed that vector preparations were relatively pure and of research grade quality ( FIG. 15 ). Two-weeks post-intracranial injection, we observed significant neuronal transduction within the injected regions using these vector preparations. However, no evidence for colocalization was found between GFP and GFAP labeling throughout the injected brains (n=3) ( FIG. 16 ), as previously reported [Cearley et al., Mol Ther 16: 1710-1718 (2008)], suggesting the astrocyte transduction in this work may be injection route- and serotype-dependent and not due to vector purity.
[0125] The scarcity of LMN and DRG transduction seen in the adult paradigm suggests there is a developmental period in which access by circulating virus to these cell populations becomes restricted. Assuming a dependence on retrograde transport for DRG and LMN transduction following intravenous injection, Schwann cell or synapse maturation may be an important determinant of successful AAV9 LMN and DRG transduction. Direct intramuscular injection of AAV9 into adults did not result in readily detectable expression in motor neurons by retrograde transport. These results suggest that AAV9 escapes brain vasculature in a similar manner as skeletal and cardiac muscle vasculature. Once free of the vasculature, these data suggest that AAV9 infects the astrocytic-perivascular-endfeet that surround capillary endothelial cells [Abbott et al., Nat Rev Neurosci 7: 41-53 (2006)].
[0126] In summary, these results demonstrate the unique capacity of AAV9 to efficiently target cells within the CNS, and in particular widespread neuronal and motor neuron transduction in the neonate, and extensive astrocyte transduction in the adult following intravenous delivery. A simple intravenous injection of AAV9 as described herein may be clinically relevant for both SMA and ALS. In the context of SMA, data suggest that increased expression of survival motor neuron (SMN) gene in LMNs may hold therapeutic benefit [Azzouz et al., The Journal of Clinical Investigation 114: 1726-1731 (2004); Baughan et al., Mol Ther 14: 54-62 (2006)]. The importance of the results presented here is that a single injection may be able to effectively restore SMN expression levels in LMNs. Additionally, given the robust neuronal populations transduced throughout the CNS in neonatal animals, this approach may also allow for rapid, relatively inexpensive generation of chimeric animals for gene overexpression, or gene knock-down [Siegel et al., PLoS Biology 2: e419 (2004)]. Additionally, constructing AAV9 based vectors with neuronal or astrocyte specific promoters may allow further specificity, given that AAV9 targets multiple non-neuronal tissues following intravenous delivery [Inagaki et al., Mol Ther 14: 45-53 (2006); Pacak et al., Circulation Research 99: e3-9 (2006)]. The results also demonstrate efficient targeting of astrocytes in adult-treated animals, and this finding is relevant for treating ALS, where the non-cell autonomous nature of disease progression has recently been discovered, and astrocytes have been specifically linked to disease progression [Yamanaka et al., Nature Neuroscience 11: 251-253 (2008)]. The ability to target astrocytes for producing trophic factors, or to circumvent aberrant glial activity may be beneficial for treating ALS24. In sum, these data highlight a relatively non-invasive method to efficiently deliver genes to the CNS and are useful in basic and clinical neurology studies.
Example 9
[0127] The ability of scAAV9 to traverse the blood-brain barrier in nonhuman primates [Kota et al., Sci. Transl. Med. 1: 6-15 (2009)] was also investigated. A male cynomolgus macaque was intravenously injected on P1 with 1×10 14 particles (2.2×10 11 particles/g of body weight) of scAAV9-GFP and euthanized it 25 days after injection. Examination of the spinal cord revealed robust GFP expression within the dorsal root ganglia and motor neurons along the entire neuraxis, as seen in P1-injected mice. This finding demonstrated that early systemic delivery of scAAV9 efficiently targets motor neurons in a nonhuman primate.
Example 10
[0128] Self complementary (sc) rAAV9 bearing MECP2 cDNA under control of a fragment of its own promoter (scAAV9/MECP2), was shown to be capable of significantly stabilizing or reversing disease phenotypes when administered systemically into female RTT mouse models.
[0129] To counteract possible over-expression and better mimic the expression pattern of virally-mediated MECP2, a rAAV9 containing MECP2 (E1) cDNA under control of an ˜730 bp fragment of its own promoter was constructed [Rastegar et al., PloS One, 4: e6810 (2009)] (scAAV9 MECP2; FIG. 17 ).
[0130] Mouse MECP2-α polynucleotide was cloned in a plasmid downstream of a 730 bp fragment of MECP2 promoter. Recombinant AAV9 was produced by transient transfection procedures using a double-stranded AAV2-ITR-based MECP2 minimal promoter—MECP2 (E1) vector, with a plasmid encoding Rep2Cap9 sequence as previously described along with an adenoviral helper plasmid pHelper (Stratagene) in 293 cells [Gao et al., J. Virol. 78: 6381-6388 (2004) and Fu et al., Mol. Ther., 8(6): 911-917 (2003)]. Virus was purified by cesium chloride density gradient purification steps as previously described, dialyzed against PBS and formulated with 0.001% Pluronic-F68 to prevent virus aggregation and stored at 4° C. [Ayuso et al., Gene Ther., 17(4):503-510 (2010)]. All vector preparations were titered by quantitative PCR using Taq-Man technology. Purity of vectors was assessed by 4-12% SDS-acrylamide gel electrophoresis and silver staining (Invitrogen). The resulting rAAV9 was named “scAAV9/MECP2.” The sequence of its genome is shown in FIG. 22 and has in sequence: a mutated AAV2 ITR lacking the terminal resolution site, an approximately 730 bp murine MECP2 promoter fragment, SV40 intron sequences, murine MECP2α cDNA, a bovine growth hormone polyadenylation signal sequence and an AAV2 ITR.
[0131] Mice were group housed with littermates in standard housing on a 12:12 h light:dark cycle. MECP2 Stop (Stock number: 006849) [Guy et al., Science, 315: 1143-1147 (2007)] and MECP2 Bird.knockout (Stock number: 003890; MECP2 Bnull ) [Guy et al., Nature Genetics, 27: 322-326 (2001)] mice were obtained from Jackson Laboratories and were on a C57BL/6 background. The wild type male mice were crossed to female MECP2 +/Stop and MECP2 +/Bnull mice to yield male and female MECP2 Stop and MECP2 Bnull genotypes. The floxed Stop sequence was identified from tail biopsies using the following primers: common 5′-AACAGTGCCAGCTGCTCTTC-3′, WT 5′-CTGTATCCTTGGGTCAAGCTG-3′, and mutant 5′-GCCAGAGGCCACTTGTGTAG-3′. For Bird null following primers were used 5′-CCACCCTCCAGTTTGGTTTA-3′ and 5′-GACCCCTTGGGACTGAAGTT-3′ [Lioy et al., Nature, 475: 497-500 (2011)].
[0132] Mice were placed in a restraint that positioned the mouse tail in a lighted, heated groove. The tail was swabbed with alcohol then injected intravenously with a 300 μl viral solution containing 3×10 12 DNase-resistant particles of scAAV9 in PBS ( FIG. 20 , panel A). After the injection, mice were returned to their cages. All animal procedures were approved by Oregon Health and Science University Institutional Animal Care and Use Committee.
[0133] For phenotype scoring, mice were removed from their home cage and placed onto a metal laminar flow hood for observation.
[0134] For mobility: 0=wild type; 1=reduced movement when compared to wild type, with extended freezing periods or extended delay to movement when first placed on the surface; 2=complete loss of movement when placed on the surface.
[0135] For gait: 0=wild type; 1=hind limbs spread wider than wild type when ambulating and/or a lowered pelvis when ambulating; 2=lack of full strides by hind limbs resulting in a dragging of hindquarters.
[0136] For hind limb clasping: 0=WT; hind limbs splay outward when suspended by the tail; 1=one hind limb is pulled into the body or forelimbs are stiff and splayed outward without motion; 2=one hind limb is pulled into the body and forelimbs are stiff and splayed outward without motion and might form a widened bowl shape, or both hind limbs are pulled into the body with or without abnormal forelimb posture.
[0137] For tremor: 0=no tremor; 1=intermittent mild tremor; 2=continuous tremor or intermittent violent tremor.
[0138] For general condition: 0=shiny coat, clear and opened eyes, normal body stance; 1=dull or squinty eyes, dull or ungroomed coat, somewhat hunched stance; 2=piloerection, hunched stance.
[0139] For behavioral testing, all tests were performed at the same time of day (12.00 to 18.00 hrs) and in the same dedicated observation room. Mice were never subjected to multiple tasks on the same day.
[0140] Open field activity—Mice were placed singly into the center of an open field arena (14×14 inches) equipped to record live images from the top. Activity was recorded for 20 minutes using StereoScan Software (Clever Systems) on a Dell computer fitted with a window operating system. Software calculated the total distance travelled and average velocity of the movements from recorded movies. The mice could not see the experimenter during recordings.
[0141] Rotorod—Mice were placed on an elevated rotating rod (diameter: 7 cm, elevated: 45 cm, Economex, Columbus Instruments, Columbus, Ohio, USA), initially rotating at 5.0 rpm. The rod accelerated 5.0 rpm/s. The latency to fall (s) was recorded manually by using individual mouse specific stopwatches. Each mouse receives three trials per day, with no delay between trials, on three consecutive days.
[0142] Platform test—Performed as described in Grady et al., J. Neuroscience, 26: 2841-2851 (2006) with some modifications. Each mouse was timed for how long it remained on an elevated, circular platform (3.0 cm in diameter) with rounded edges. A maximum score of 60 s was assigned if the mouse remained on the platform for the entire test trial without falling. Two trials were administered for each test with 4 h intervening between trials, and means were calculated across the trials for each mouse.
[0143] Inverted screen test—Performed as described in Grady et al., 2006 with some modifications. Each mouse was placed in the middle of wire grid (parallel metal wires 0.5 cm apart) that was inverted to 180°. A mouse was timed for how long it remained upside down on the screen, with a maximum score of 60 s being given if the animal did not fall. Two trials were administered for each test with 4 h intervening between trials, and means were calculated across the trials for each mouse.
[0144] Nesting ability-Mice were placed in individual cages and provided with a nest building material (5 cm×5 cm×0.5 cm). The material was placed in top left corner of cage and nesting ability was scored over night based on the interaction of individual mouse with nesting material. The score of 0, 1, 2 and 3 were assigned. The score 0 was assigned to mouse that not at all interacted with material, score 3 was assigned to mouse that completely used the material to build a nest.
[0145] Novel Object recognition test—Test is conducted in open field arena used to evaluate motor activity. The two objects (a sphere and a box) were selected based on similar volume and unbiased interaction of wild type mice. During habituation, the mice were allowed to explore an empty arena for 5 minutes. Twenty-four hours after habituation, the mice were exposed to the familiar arena with two identical objects (sphere) placed at an equal distance for 5 minutes. The next day, same exercise was repeated. On third day of the test, the mice are allowed to explore the open field in the presence of the familiar and a novel object (Box) for 5 minutes to test cognition. The time spent exploring each object on second and final day of test was recorded to estimate the extent of novel object recognition by calculating discrimination index (DI)=(Tn−Tf)/(Tn+Tf). Tn; time with novel object and Tf; time with familiar object. The DI value can vary between +1 and −1, where a positive score indicates more time spent with the novel object, a negative score indicates more time spent with the familiar object, and a zero score indicates a null preference.
[0146] After phenotypic scoring and behavioral testing, mice were anaesthetized by intraperitoneal injection of Avertin (2-2-2 Tribromoethanol) and sacrificed by transcardial perfusion of 4% parafomaldehyde in phosphate-buffered saline. Brains were equilibrated in 30% sucrose overnight at 4° C. Sagittal sections (40 μm) were cut at −20° C. using a cryostat (Leica) and stored at −20° C. Sections were immunolabeled overnight at 4° C. using the following primary antibodies: rabbit-MECP2 (1:500, Covance), mouse-GFAP (1:500, Abcam), chicken-GFAP (1:200, Abcam), mouse-NeuN (1:200, Millipore). Appropriate Alexa/Dylight Fluor secondary antibodies (1:500, Molecular Probes) were used for 1 h at room temperature. DAPI was present in the ProLong Gold Antifade (Invitrogen) mounting reagent. Nissl staining (at either 594 nm or 640 nm) was performed as instructed by the manufacturer (NeuroTrace, Invitrogen). All images were collected on a Zeiss confocal laser scanning LSM 510 microscope.
[0147] MECP2 expressing cells were identified as described in Lioy et al. (2011) with some modifications: nuclei of astrocytes (GFAP+ at 555 nm or 640 nm; NeuN− at 555 nm or 640 nm) and neurons (NeuN+ at 555 nm or 640 nm) were first identified by DAPI staining. Cells with clearly identified nuclei were then assessed for MECP2 expression by analyzing 505 nm signal (excitation: 488 nm) in the nucleus.
[0148] The following measurements were analyzed using one-way ANOVA followed, when appropriate (P<0.05), by Newman-Keuls post-hoc test: anatomical and cell-type expression patterns of transduced MECP2, whole body and brain weights, respiratory parameters, open field activity and time on rotarod. The following measurements were analyzed using Kruskal-Wallis test followed, when appropriate (P<0.05), by Dunn's multiple comparisons test: phenotype severity scores, nesting scores, time on an inverted grid, time on a platform, and novel object recognition. Survival curves were compared using the Log-Rank method. All statistics were performed using PRISM 5.0 software.
[0149] The scAAV9/MECP2 construct is expressed in both neurons and glia in vitro, and in MECP2Bnull/y mice, virally-expressed MECP2 was detected immunochemically in heterochromatic puncta of both cell types, indicating wild type DNA binding function. Notably, MECP2-positive neurons in the CA3 region of scAAV9/MECP2-injected males had significantly larger somal sizes than MECP2-negative neurons.
[0150] The MECP2 expressed from scAAV9/MECP2 was detected throughout the brain. However, with the exception of cerebellum, MECP2 expression was not over represented in astrocytes, ( FIG. 18 ). This could reflect, in part, the specific cell specific regulatory elements in the cloned promoter fragment because MECP2 is expressed generally at lower levels in astocytes than neurons [Ballas et al., Nature Neuroscience, 12: 311-317 (2009) and Skene et al., Molecular Cell, 37: 457-468 (2010)]. Consistent with all of these metrics, the injected male mice had prolonged lifespans and improved observational scores compared to control injected mice ( FIG. 19 , panels a and b).
[0151] A potential concern with virally-mediated gene transfer of MECP2 is over-expression, because MECP2 duplication gives rise to a neurological disease [del Gaudio et al., Genetics in Medicine, 8: 784-792 (2006) and Friez et al., Pediatrics, 118: e1687-1695 (2006)]. To assess this issue, in an unbiased manner, the average MECP2 expression level was determined in transduced brains by recording field pixel intensities of MECP2-Cy3 fluorescence in hindbrain sections selected randomly. The results indicated that scAAV9/MECP2 injection resulted in physiological levels of MECP2 protein ( FIG. 19 , panel c). Interestingly, WT brains showed two peaks of MECP2 fluorescence that were precisely recapitulated in the MECP2 transduced brains, although the cellular nature of the fluorescence is not identified by this method of analysis.
[0152] Having established that scAAV9/MECP2 programmed MECP2 expression to approximately physiological levels in multiple cell types in brain, rescue parameters were examined in 10 to 12 month-old symptomatic MECP2Bnull/+ mice that were systemically injected with scAAV9/MECP2 or control virus ( FIG. 21 ). Like the males, there was no evidence for over-expression of MECP2 and viral therapy did not compromise survival ( FIG. 19 , panel c; FIG. 21 ). The observational scores increased initially from two to three. Strikingly, by 12-weeks, scAAV9/MECP2 injected females stabilized at an improved score of one until the end of scoring at 24-weeks, while females injected with control virus progressed to a score of nearly six ( FIG. 20 , panel b). The scAAV9/MECP2 injected MECP2Bnull/+ mice also performed significantly better than scAAV9/control females in rotorod, inverted grid and platform tests, and nesting ability ( FIG. 20 , panels c-f). None of the injected females exhibited seizures, unlike the females injected with control virus (2/5).
[0153] Previous gene therapy work has shown modest, but encouraging, improvement of symptoms in male mouse models of RTT [Gadalla et al., Mol. Ther., 21: 18-30 (2013)]. However, the disease initiates and progresses differently in females and males, due to the mosaic nature of MECP2 loss of function in females. Therefore, therapeutics designed especially for affected females are required. The results presented herein are important because they suggest, for the first time, that symptoms in human RTT female patients may be reversible by ectopic expression of MECP2 in a rAAV9 virus that infects peripheral tissue and multiple cell types within the CNS. Interestingly, the experiments also indicate that not every cell needs to be repaired with MECP2 in order to stabilize or reverse phenotypes in female mice, consistent with the finding that an ˜5% increase in MECP2 levels over WT levels is sufficient to mediate longer lifespans [Robinson et al., Brain, 135: 2699-2710 (2012) and Lioy et al. (2011).
[0154] While the present invention has been described in terms of various embodiments and examples, it is understood that variations and improvements will occur to those skilled in the art. Therefore, only such limitations as appear in the claims should be placed on the invention.
[0155] All documents referred to in this application, including priority documents, are hereby incorporated by reference in their entirety with particular attention to the content for which they are referred.
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The present invention relates to Adeno-associated virus 9 methods and materials useful for systemically delivering polynucleotides across the blood brain barrier. Accordingly, the present invention also relates to methods and materials useful for systemically delivering polynucleotides to the central and peripheral nervous systems. The present invention also relates to Adeno-associated virus type 9 methods and materials useful for intrathecal delivery of polynucleotides. Use of the methods and materials is indicated, for example, for treatment of lower motor neuron diseases such as spinal muscle atrophy and amyotrophic lateral sclerosis as well as Pompe disease and lysosomal storage disorders. Use of the methods and materials is also indicated, for example, for treatment of Rett syndrome.
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FIELD OF THE INVENTION
This invention relates to a mechanical seal construction, and particularly a bellows-type seal construction provided with a vibration damper for cooperation between the shaft and surrounding seal ring.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,261,581, assigned to Durametallic Corporation, discloses a mechanical seal construction employing a pair of opposed face rings which are disposed in relatively rotatable and sliding sealing engagement with one another. One face ring is fixedly related relative to a surrounding housing, and the other surrounds and is nonrotatably mounted relative to a rotating shaft. The rotating face ring is typically spaced radially outwardly from the shaft to define a substantial annular clearance space therebetween, and this face ring is coupled to one end of an axially elongate bellows which surrounds the shaft and at its other end is coupled to a collar which is fixedly and sealingly coupled to the shaft. This known mechanical seal construction is widely and successfully utilized in many environments, such as the chemical and petrochemical industries, requiring a sealing relationship for confining fluids, particularly corrosive and/or high-temperature fluids.
In the known and extensively utilized mechanical seal construction described above, the face rings are normally and preferably constructed of a carbide material, generally either silicon carbide or tungsten carbide, so as to both withstand the desired operating conditions and provide a desirable seal life. However, due to the extreme hardness of such carbide face rings, they have necessarily been maintained in substantial radially spaced relationship from the shaft so as to prevent contact therebetween due to the mechanical vibration which exists in the conventional mechanical seal environment, which vibration between the face rings and the shaft occurs in numerous forms and modes, including axial, radial and torsional vibrations.
Since such mechanical vibrations have long created problems with respect to wear and durability of mechanical seals, particularly those constructions involving metal bellows, seal designers have attempted to utilize various structural modifications in the seal construction so as to more closely control and confine the rotating seal parts relative to the shaft to prevent wear or failure due to such vibration. In one commonly and long utilized construction, the support ring for the rotating face ring is provided with several (normally three) tabs formed integrally thereon and projecting radially thereof so as to create a very close fit with the shaft, the clearance between these tabs and the shaft typically being a few thousands of an inch. These tabs and their close clearance with the shaft are intended to provide a much closer confinement, at least radially, of the rotating seal parts relative to the shaft, and hopefully minimize vibration. The Assignee's experience with this type of vibration dampening technique, however, through both field experience and laboratory testing, indicates that this vibration dampening construction creates more problems than it solves. For example, fretting damage between the shaft and the vibration dampening tabs occurs due to misalignment of the seal faces with respect to the shaft axis. Forced vibration of the support ring back and forth (that is, axially) also frequently results in fretting damage to the pump shaft. This damage and the adverse loads imposed on the support ring may be great enough to cause face separation, undesirably high leakage rates, or even hang up of the bellows. Close clearances of the vibration dampener tabs with the shaft also make the seal construction susceptible to hang up due to crystals or solids forming on the atmospheric side of the seal or thermal expansion of the shaft inside the vibration dampener tabs. Thus, this type of vibration dampening structure is, in many use situations, undesirable or unacceptable.
In an attempt to overcome the fretting and hang up problems caused by a vibration damper of the aforementioned type, mechanical seal constructions have also used a vibration damper constructed of a plastics or elastomeric material. Such vibration damper is generally comprised of a ring member which is axially rather thin, and which is fixedly clampingly held between the rotating face ring and its support ring. This elastomeric dampener ring projects radially inwardly so as to create a close fit with the shaft. While this elastomeric dampener ring obviously eliminates the fretting problem, nevertheless it has been observed to create other operational problems. For example, this elastomeric dampener has been observed to hang up on the shaft and thus effectively act as a seal, thereby interfering with proper operation of the mechanical seal construction. The elastomeric dampener also undergoes deterioration, particularly in view of the highly corrosive or high temperature fluids with which seals of this type are commonly used, and in addition the known dampeners have been of very short axial extent and accordingly have performed with only limited success.
In a very small number of use conditions, a mechanical seal construction in provided with carbon face rings rather than carbide face rings. Such carbon face rings are typically not used since they have a very short operational wear life. However, in situations where they are used, they have been constructed so as to have an inside diameter which provides only a minimal clearance relative to the shaft to minimize the vibration problem. While such a carbon face ring has been observed to operate in a satisfactory manner with respect to minimizing vibration problems, nevertheless such is not a fair evaluation of the overall seal construction performance, including an evaluation of the vibration problem, since such carbon face ring itself exhibits a very poor life cycle, such that the vibration problem itself may no longer be of primary concern.
Accordingly, it is an object of this invention to provide an improved bellows-type mechanical seal construction employing carbide face rings, which seal construction overcomes many of the above-mentioned disadvantages and operational problems.
In the improved bellows-type mechanical seal construction of this invention, the rotating carbide face ring has a vibration damper mounted thereon, the latter preferably being constructed as a carbon ring which is fixedly mounted within the carbide face ring, preferably by means of a press fit. The carbon vibration dampener ring is of substantial axial extent, and provides a close clearance with the shaft to effectively dampen vibrations of the rotating seal parts while at the same time avoiding damage to or hang up on the shaft.
In the improved seal construction, as briefly summarized above, the carbon dampener ring preferably has an axially length which is somewhat shorter then the axial length of the carbide face ring, the latter being supportingly positioned so that it has a nose part which projects axially beyond the carbon dampener ring, with this nose part defining thereon a seal face which slidingly contacts an opposed seal face on the stationary face ring. This arrangement thus prevents build up of coke and debris in or directly adjacent the plane of the seal face.
With the improved seal construction of this invention, a bellows-type seal is able to retain use of carbide face rings so as to provide optimum life, and at the same time the face ring can be desirably closely and concentrically supported relative to the shaft by means of the intermediate carbon dampener ring so as to effectively dampen vibrations and minimize problems caused by such vibration, and at the same time the carbon dampener ring effectively provides a long and concentric area for supporting engagement with the shaft, which engagement area is effectively self lubricating and does not create any fretting of the shaft or hang up of the seal parts. At the same time, the carbon ring is able to maintain the desirable and necessary minimal clearance between the carbon dampener ring and the shaft so as to not create a total seal at this point, and still permit the necessary floating movement (both radial and angular float) of the face ring as required in order to achieve optimum seal performance.
Other structural features, objects and purposes of the invention will be apparent to persons familiar with seal constructions of this general type upon reading the following specification and inspecting the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary axial sectional view of a conventional bellows-type mechanical seal assembly.
FIG. 2 is an enlarged fragmentary axial sectional view according to the present invention.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words "upwardly", "downwardly", "rightwardly" and "leftwardly" will refer to directions in the drawings to which reference is made. The words "inwardly" and "outwardly" will refer to directions toward and away from, respectively, the geometric center of the seal construction and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.
DETAILED DESCRIPTION
FIG. 1 illustrates a conventional bellows-type mechanical shaft seal construction 10 associated with an apparatus which includes a wall 11 having an opening 12 through which extends a shaft 13 rotatable about its axis 14. The wall 11 may be part of any conventional fluid handling device, such as a pump, whereby pressurized fluid is thus present within the apparatus and tends to escape through the opening 12.
To prevent escape of fluid, the seal arrangement 10 is provided for creating a sealed relationship between wall 11 and shaft 13. For this purpose, the seal arrangement 10 includes a conventional annular stuffing box or housing 16 secured to the wall 11 in surrounding relationship to the shaft. The stuffing box defines an annular chamber 17 which communicates with the opening 12. A conventional throat bushing 18 is normally associated with the end of this chamber 17 for restricting flow of pressure fluid through the opening into the chamber.
A further annular housing element 19, commonly referred to as a gland, is positioned directly adjacent the stuffing box 16 and is suitably sealed thereto, as by an intermediate gasket 21. A plurality of conventional threaded fastener elements (not shown) are used for fixedly interconnecting the stuffing box 16 and gland 19 to the wall 11.
An "inside" type of mechanical seal assembly 23 is disposed within the annular chamber 17 for creating a sealed relationship between the shaft 13 and the gland 19, while permitting relative rotation therebetween. The mechanical seal assembly 23 is of the bellows type and includes a stationary seal portion 24 which is nonrotatably connected to the gland 19. This portion 24 includes an annular seal member 26 (commonly referred to as a gland insert) which is nonrotatably connected to the gland 19 by a suitable key or pin 27. A sealing ring or gasket 28 is provided between the gland 19 and the insert 26.
Insert 26 has an annular flange 29 which projects axially from the inner end thereof, which flange snugly and supportingly embraces (by means of an interference or press fit) an annular face ring 31, which latter ring defines a flat annular seal face 32 on the outer or exposed axial end thereof. A suitable annular clearance 33 exists between the insert 26 and the shaft 14 to permit unrestricted relative rotation and angular or lateral movement or deflection of the shaft relative to the surrounding housing.
The mechanical seal assembly 23 also includes a rotatable seal portion 34. This latter portion 34 includes an annular collar 36 formed by first and second ring-like collar members 37 and 38, respectively, which are fixedly connected by suitable screws or the like. The collar is fixed to the shaft 13 by any conventional means, such as a set screw 39. A suitable seal ring or gasket 41 is clampingly sealed between the two collars to create a sealed engagement with the periphery of the shaft 13.
Rotary seal portion 34 also includes a rotatable annular seal ring 42 which surrounds the shaft 13 and has an inner diameter which is substantial larger than the shaft 13 to permit relative lateral and/or angular movement therebetween. The seal ring 42 has an annular flange 43 which projects axially from the outer end thereof, which flange defines a recess in which is positioned an annular face ring 44, the latter being fixedly mounted and supported on the seal ring by means of a press or interference fit within the flange 43. The face ring 44 defines a transverse or radial seal face 46 on the outer axial end thereof, which face 46 is urged into rotatable slidable engagement with the opposed seal face 32. The rear face 47 of the face ring 44 is seated against a bottom surface 48 as defined on the seal ring 42.
The seal assembly 23 also includes a conventional metal bellows seal 22 which extends between the collar 36 and the seal ring 42 for nonrotatably and sealingly joining same together. This bellows seal 22 encircles the shaft and has one end thereof fixedly and sealingly connected, as by welding, to the collar 38. The other end of bellows seal 22 is fixedly and sealingly connected, as by welding, to the seal ring 42. The bellows seal 22 is of substantially conventional construction and includes a plurality of individual bellows plates, preferably of stainless steel, suitably welded together.
The bellows seal 22 also functions as a resilient device for normally resiliently urging the seal ring 42 toward the gland insert 26, thereby maintaining the seal faces 32 and 46 in sealing engagement with one another. Additional resilient can be provided, if necessary, by utilization of one or more conventional coil springs positioned for cooperation between the collar 38 and the seal ring 42.
The face rings 31 and 44 are construction of carbide, such as tungsten carbide or silicon carbide. The rotating face ring 44 generally has an axial extent which exceeds its radial thickness, and the inner diameter of the ring 44 as defined by the cylindrical inner wall 49 is substantially larger than the diameter of shaft 13 so that wall 49 is spaced radially a substantial distance from the shaft.
The overall seal construction illustrated in FIG. 1, including the structure and operation thereof, is conventional. Reference is made to U.S. Pat. Nos. 4,261,581 and 3,773,337 wherein this type of arrangement is described in greater detail.
Considering now the improvement according to the present invention and referring to FIG. 2, the rotating carbide face ring 44 is provided with a vibration dampening ring 51 fixedly positioned therein. This ring 51 is disposed within the inner cylindrical wall 49 of the carbide face ring 44 by means of an interference or press fit so that the rings 44 and 51 are fixedly joined together. The vibration dampening ring 51 has an inner diameter or cylindrical wall 52 which is only slightly larger than the outer diameter of the shaft 13, thereby providing a diametral clearance therebetween in the range from about 0.005 inch to about 0.025 inch.
The dampening ring 51 is preferably constructed of carbon and, as shown by FIG. 2, is of significant axial length. In fact, the ring 51 has a length which equals a substantial majority of, but is slightly less than the maximum axial length of the carbide face ring 44. The carbon ring 51 has a rear face 53 which is preferably disposed substantially flush with the rear face 47 of the carbide face ring. The front face 54 of the ring 51, however, is spaced axially rearwardly or inwardly from the seal face 46 so as to prevent any buildup of debris or coke on the carbon ring from interfering with the seal face 46.
The ring 51, on the outer diameter thereof adjacent the front face 54, is provided with a small chamfer 56 on the corner thereof to facilitate the pressing of the carbon ring 51 into the carbide ring 44 from the leftward side of the latter. The face 54 of ring 51 is preferably disposed axially rearwardly from the seal face 46 by at least about 0.006 inch.
The carbon ring 51 always has an axial length which is greater than its radial thickness. For example, the dimensions of this carbon ring may range from an outer diameter of about 1.20 inch having a radial thickness of about 0.25 inch and an axial length of about 0.30 inch, to an outer diameter of about 4.78 inch having a radial thickness of about 0.40 and an axial length of about 0.50 inch.
In operation, the improved mechanical seal construction illustrated by FIG. 2 utilizing the carbon vibration dampening ring 51 is able to significantly minimize and control vibration of the seal construction, particularly the severe bellows vibration which has been observed to develop in situations where a mechanical seal is permitted to run under a dry condition. At the same time, the carbon ring 51 is able to retain sufficient radial clearance as to not interfere or restrict the necessary radial displacement or angular tilting of the face ring 44 so as to enable it to always maintain a desired running conformance and sealed engagement with the stationary face ring 31. The ring 51 itself is somewhat self-lubricating which, when coupled with its significant axial length, prevents it from fretting the shaft or hanging up. Except for the significant improvement achieved with respect to eliminating or minimizing vibrational effects, the seal construction otherwise operates in a conventional manner.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.
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A bellows-type mechanical seal construction having a rotating carbide face ring provided with a vibration damper mounted thereon. The vibration damper comprises a carbon ring which is fixedly mounted within the carbide face ring, as by a press fit. The carbon vibration dampener ring is of substantial axial extent, and provides a close clearance with a shaft to effectively dampen vibrations of the rotating seal parts.
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PRIORITY CLAIM
[0001] The present application is a National Phase entry of PCT Application No. PCT/EP2011/001114, filed Mar. 7, 2011, the disclosure of which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to chains formed of oval profile chain links.
BACKGROUND OF THE INVENTION
[0003] Chains consisting of oval profile chain links are known in which the cross-sections of the sectional steels used, in particular on the end webs connecting the longitudinal limbs of the chain links at their ends, have a circular cross-section (US 2006/0053766 A1, DE 2007 061 512 A1).
[0004] In other known chains (DE 10 2008 034 360 A1), although the cross-sections of the end webs do not have a circular cross-section, they are formed circularly rounded on their sides facing the inner opening of the chain link in question.
[0005] In both cases, however, this has the result, when a finished chain is under tension, that the end webs in each case of two chain links engaging in one another come into contact engagement with one another on their insides, with their bearing or supporting surfaces provided there, wherein the insides of the end webs of one chain link rest against the inside of the end webs of the other chain links, arranged swivelled by 90° to them about their longitudinal axis. On such end webs, resting against one another, of in each case two chain links hooked into one another, articulation points are formed which become active when the round steel chain in question carries out a change of direction under load, for instance when running around a guide roller or during other changes of direction taking place under load. This results in the occurrence of wear at such articulation points of round steel chains under load, which can, in the end, result in the need to at least replace chain links worn out at the end webs of the articulation points, if not the need to replace the entire chain.
[0006] To produce such chains, it is known (DE 10 2007 061 512 A1), for the individual chain links, to convert corresponding profile or round steel sections into a shape corresponding to the desired chain link shape (oval, round), to hook them into one another and then connect the end faces of the pre-bent sectional steel sections to one another by welding. Since each individual chain link here has to be pre-bent into an open shape and then closed later by welding, the production of such chains is expensive.
[0007] A method of the type named at the start for producing chain links is known from DE 32 12 360 C1, in which closed chain links are hooked into open chain links and then the open chain links are closed by resistance butt welding. Used as open chain links are those chain links which consist of a U-shaped lower part and a rod-shaped upper part, wherein the ends to be welded together of the lower and upper parts of the open chain links are provided, before the welding, with substantially roof-shaped tapers, the apexes of which intersect in the welding position. As a result of this design, the conductive connection between the upper and the lower part is improved and an intensive heating in the area of the weld points is achieved, wherein small unintended shifts during assembly do not adversely affect the strength of the weld point. In this method only every second chain link is welded, whereby the manufacturing efficiency of the welding machine used is doubled compared with the known methods in which every chain link has to be welded. However, the particular design of the end faces of the U-shaped lower part as well as of the underside of the rod-shaped upper part requires an additional outlay.
[0008] The use, recommended there, of round stock on the end webs of these known chain links moreover also does not yield any improvements with respect to the life of these chain links due to joint wear.
[0009] Starting from here, the task of the invention is to improve a chain of the type named at the beginning such that the available wear volume in the joints is enlarged and thus the life of the individual chain links is increased.
[0010] In addition, the object of the invention is also to propose a method for producing such a chain which can be carried out simply and in which the production outlay is particularly low.
SUMMARY OF THE INVENTION
[0011] A chain consisting of oval profile chain links, in which each end web connecting the two longitudinal limbs of a chain link to one another at an end side of same is supported, with a cylindrical supporting surface formed on its inside, on a cylindrical bearing surface provided on the inside of the associated end web of the hooked-in adjacent profile chain link. The invention further relates to a method for producing such chains, in which closed profile chain links are hooked into open profile chain links and then the latter are closed by welding, wherein when the chain is in the finished state each end web connecting the two longitudinal limbs of each chain link to one another at an end side of same is supported, with a cylindrical supporting surface formed on its inside, on a cylindrical bearing surface provided on the inside of the associated end web of the hooked-in adjacent profile chain link.
[0012] According to embodiments of the invention, it is provided that the supporting surfaces and the bearing surfaces of all end webs are widened in each case laterally beyond the two lateral boundary surfaces of the end web in question, and supporting and bearing surfaces associated with one another are formed in each case as cylindrical surfaces that complement one another over the entire width of these widened surfaces.
[0013] With the profile chain according to the invention, the special design of the end webs, namely their supporting surfaces or their bearing surfaces which are widened laterally beyond the two lateral boundary surfaces of the end web in question and are formed in each case as cylindrical surfaces that complement one another over the entire width of these widened surfaces, means that these supporting and bearing surfaces resting on one another under load and in each case forming an articulation point between two successive chain links are much larger surfaces than in the case of pure round links and provide a substantially larger wear volume in the joint than in the case of a round steel chain (with equal breaking force). However, owing to the enlarged surface, the surface pressure acting under a load is also reduced by this design optimization according to the invention of the joint, which in turn results in a more favorable wear behavior than in the case of pure round steel chains. Because, at such an articulation point between the two profile chain links hooked into one another, the supporting surface on the end web of one chain link and the bearing surface on the end web of the other chain link are not only widened laterally, but in each case are formed as cylindrical surfaces that complement one another substantially over the entire width of this widened surface, so that the supporting surface of one chain link has a (namely circular) curvature only in planes lying parallel to the clamping surface of same, while the bearing surface on the other chain link is provided with a complementary curvature in the shape of a circular segment only in planes perpendicular to its clamping surface, thus two cylindrical surfaces which interlink form the articulation point, forces acting in the load direction of the chain between the supporting surfaces and bearing surfaces running on one another are transferred between the chain links in each case in radial direction, which means a favorable introduction or discharge into or out of the respective end web. Owing to the cylindrical shape of the joint bearing points running on one another, a very uniform stress also occurs in the bearing surfaces, as, seen over the width of the bearing surface, in each case equally large local relative speeds occur between the two bearing surfaces, thus a very uniform local speed is also present over the bearing surfaces, which likewise results in a very uniform, favorable wear behavior.
[0014] The chain links can preferably be produced by forging or also casting or also by sintering, wherein as a result of these production methods the special shape of the chain links can very advantageously be freely adapted to the defined purpose of the chain (for lifting, conveying or fastening).
[0015] If, in the case of a chain according to the invention, the individual chain links are used as vertical links and as horizontal links, in the case of the profile chain links serving as vertical links the widening of their supporting surface is preferably provided substantially along the entire curved course of the respective end web.
[0016] Likewise advantageously, in the case of the profile chain links serving as horizontal links, their bearing surfaces are formed such that they run around the respective end web on its inside and its two lateral boundary surfaces up to a circumferential surface bordering the chain link in question on its outside.
[0017] Particularly in the case of a chain according to the invention, the vertical links consist of profile chain half links connected to one another by welding, in particular by friction welding.
[0018] The chains according to the invention have, at the articulation points between two chain links hooked into one another, an advantageous formation of the bearing surfaces running on one another between the two end webs running on one another there when the chains are under load, through which a particularly favorable wear behavior, a lower specific load than in the case of profile links with round profile and thus also a much longer life for the articulation points are achieved.
[0019] The method according to the invention provides, in the case of a method for producing chain links of the type named at the beginning, for profile chain half links which are designed as half links separated in the area of the center of the longitudinal limbs of a chain link perpendicular to the clamping plane of same to be used as open chain links, wherein the supporting surfaces and the bearing surfaces of all end webs are widened in each case laterally beyond the side flanks of the end web in question, and supporting and bearing surfaces associated with one another are formed in each case as cylindrical surfaces that complement one another over the entire width of these widened surfaces.
[0020] In the production method according to the invention also only every second chain link is closed by welding, whereby the manufacturing efficiency of the corresponding welding machine is doubled compared with the production method in which every chain link has to be closed by welding.
[0021] However, it is not necessary to use different individual partial links for the open chain links and weld them together, as is the case in the production method described at the beginning. Rather, in the production method according to the invention the great advantage is achieved that only one form of partial links, in the form of half links, need be used for the formation of the open chain links, which is favorable, not only for the production, but also for the storage, because there is no need to provide and use differently formed partial links. The end faces to be welded together in each case of two half links facing one another also lie inside a chain link symmetry plane, which is favorable for carrying out the welding process.
[0022] Any suitable welding process can be used to connect the half links.
[0023] However, for the connection of in each case two profile chain half links to create a closed profile chain link, friction welding has proved to be quite particularly advantageous as well as quick and favorable to carry out, wherein here linear friction welding is, again quite particularly preferably, used.
[0024] If work is done by means of friction welding, the great advantage can be achieved that, for the profile chain links, those made of plastic can also be readily used.
DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is the perspective view of a section, consisting of four successive chain links, of a profile chain according to the invention;
[0026] FIG. 2 is an (enlarged) perspective view of a chain link (horizontal link) of a chain according to the invention;
[0027] FIG. 3 is a top view of the profile chain link according to FIG. 2 ;
[0028] FIG. 4 is a sectional representation according to cut layer E-E in FIG. 3 ;
[0029] FIG. 5 is a sectional view according to cut layer D-D from FIG. 3 ;
[0030] FIG. 6 is an enlarged perspective view of a chain link (vertical link) of a chain according to the invention;
[0031] FIG. 7 is a top view of a profile chain half link cut through the center area of the side limbs of the chain link according to FIG. 6 ;
[0032] FIG. 8 is a section along cut plane F-F in FIG. 7 , and
[0033] FIG. 9 is a sectional representation according to cut plane G-G in FIG. 7 .
DETAILED DESCRIPTION
[0034] In the following description of the figures, parts with the same function in the various figures are also always provided with the same reference numbers.
[0035] Firstly, in FIG. 1 a section from a chain 1 is shown in perspective representation, which comprises, in alternating sequence, two horizontal profile chain links 2 a as well as two vertical profile chain links 2 b, wherein in each case a vertical link 2 b connects two horizontal links 2 a , into which it is hooked in each case.
[0036] The horizontal links 2 a and the vertical links 2 b are elongate, oval profile chain links made of material that is not circular in cross-section, which will be discussed in detail below.
[0037] As FIG. 1 likewise shows, the horizontal links 2 a are designed as one-piece, closed chain links, while the vertical links 2 b consist in each case of two profile chain half links 2 c which are welded together along weld points 13 , 14 on their end faces 11 , 12 facing one another (cf. FIG. 7 ) to form a closed vertical link 2 b.
[0038] The half links 2 c are formed such that each of same represents one half of a vertical link 2 b, with the result that, after welding of the two half links 2 c to form a closed vertical link 2 b , the weld points 13 , 14 on the side limbs 3 and 4 that form then are in each case arranged in the center and aligned relative to one another in a center plane corresponding to FIG. 6 .
[0039] The chain 1 is produced such that in each case a profile chain half link 2 c is hooked into a closed chain link (horizontal link 2 a ), on its two end webs 5 , 6 (cf. FIG. 2 ), through the center opening of the closed horizontal link 2 a in question, namely in such a way that the free limbs of the two hooked-in profile chain half links 2 c run in opposite directions to one another.
[0040] Then, as can be seen from FIG. 1 , the profile chain half links 2 c hooked in on two successive horizontal links 2 a are welded together in a suitable manner, with their end faces 11 and 12 facing one another, at the end of their limbs 3 and 4 , with the result that a closed vertical link 2 b connecting the two horizontal links 2 a forms.
[0041] Any suitable welding process can be used to weld the two profile chain half links 2 c together.
[0042] However, it has proved to be quite particularly advantageous if the welding at the weld points 13 and 14 is carried out by means of a friction welding process, and here quite particularly preferably by means of a linear friction welding process. Since the weld points 13 and 14 on the limbs 3 and 4 of the respective horizontal link 2 b are arranged centrally, aligned relative to one another and attached in a center plane as separation plane, a simultaneous linear friction welding of the two weld points 13 and 14 can be carried out quickly and favourably in one process.
[0043] This is even possible if the profile chain half links 2 c consist, not of a metal, but e.g. of a plastic, since friction welding or linear friction welding can also be carried out without difficulty on plastic parts.
[0044] An (enlarged) perspective representation of a horizontal link 2 a is shown in FIG. 2 and such a representation of a vertical link 2 b is shown in FIG. 6 .
[0045] Of the perspective representation of the horizontal link 2 a according to FIG. 2 , FIG. 3 shows a top view, FIG. 4 a sectional view along cut plane E-E in FIG. 3 and FIG. 5 a sectional view along cut plane D-D likewise in FIG. 3 .
[0046] The side limbs 3 and 4 are bordered on both sides by lateral boundary surfaces 9 ( FIG. 2 ) on one side and 10 ( FIGS. 4 and 5 ) on the other.
[0047] The end webs 5 and 6 also have these lateral boundary surfaces 9 and 10 , namely in the area in which the side webs 3 and 4 pass into the respective end web 5 or 6 , as can be seen well from the representation from FIG. 5 .
[0048] On each side of the horizontal link 2 a these lateral boundary surfaces 9 and 10 in each case lie inside one plane.
[0049] On the side facing the inner opening of the chain link 2 a, a bearing surface 7 is formed in each case on the end limbs 5 and 6 which, as can be seen from the representation from FIG. 5 , has a cross-section in the shape of a circular segment and runs around the respective end web 5 or 6 on its inside as well as on its two outsides in each case up to the junction with a circumferential surface 15 running around the entire chain link 2 a on the outside.
[0050] As can be seen particularly well from FIG. 5 , the cylindrical bearing surface 7 on both end webs 5 , 6 has a course that protrudes laterally by an amount b from both lateral boundary surfaces 9 and 10 of the end webs 5 and 6 (and also of the longitudinal limbs 3 and 4 ). As a result, a bearing surface 7 forms on each of the side limbs 5 and 6 , on which the corresponding supporting surface 8 of the hooked-in vertical link 2 b (cf. FIGS. 6 and 7 ), which has a likewise cylindrical, complementary shape, can be supported in sliding manner over the full laterally enlarged width c.
[0051] Since the bearing surfaces 7 on the side limbs 5 and 6 of the horizontal links 2 a are cylindrical surfaces which run in a curve only in the plane of the image represented in FIG. 5 , but do not have a curvature perpendicular to this, this thus means that, for the total width c of these cylindrical bearing surfaces 7 , an effective bearing width with a size of
[0000] c=a+ 2 b
[0000] is available, wherein a denotes the distance between the lateral boundary surfaces 9 and 10 of the horizontal link 2 a, b denotes the lateral projection over which, on each side, the bearing surfaces 7 protrude beyond the lateral boundary surfaces 9 and 10 of the end webs 5 and 6 respectively (and thus also the side webs 9 and 10 ), and c denotes the entire effective bearing width perpendicular to the clamping plane of the horizontal link 2 a.
[0052] Reference may now be made to FIGS. 6 to 9 , in which a vertical link 2 b is illustrated in enlarged representation:
[0053] This vertical link also comprises two side limbs 3 , 4 which are connected to one another at their ends in each case via an end web 5 or 6 curved in a semi-circle.
[0054] The end webs 5 and 6 have on their inside facing the inner opening of the vertical link 2 b a supporting surface 8 which, as FIG. 6 shows very well, is likewise formed cylindrical. This supporting surface 8 , as can be seen from FIGS. 6 , 8 and 9 , is widened by means of outwardly directed bulges 16 by a projection f (cf. FIGS. 8 and 9 ) over the lateral boundary surfaces 9 , 10 of the end webs 5 , 6 , which in turn lie in a common plane with the lateral boundary surfaces of the longitudinal limbs 3 and 4 on each side of the chain link 2 b. Again, a significant enlargement of the effective bearing width d of the supporting surface 8 is thus achieved in the direction of the center axis of the cylindrical shape:
[0000] d=e+ 2 f,
[0000] wherein e denotes the distance between the lateral boundary surfaces 9 and 10 of the vertical link 2 b (cf. FIG. 5 ).
[0055] The vertical links 2 b are assembled, however, not in the closed state, but in an opened state with the horizontal links 2 a, namely such that in each case two halves of vertical links 2 c are hooked into a closed horizontal link 2 a on their two end webs 5 and 6 .
[0056] FIG. 7 shows a top view of such a profile chain half link 2 c, wherein FIGS. 8 and 9 show sectional representations of this half link corresponding to the cut lines F-F ( FIG. 8 ) and G-G ( FIG. 9 ).
[0057] Each profile chain half link 2 c is thus hooked into a (closed) horizontal link 2 a (corresponding to FIGS. 2 to 5 ) for assembly, namely in a clamping plane rotated by 90° relative to said horizontal link about its longitudinal center axis, with the result that the bearing surface 8 of the vertical link 2 b comes to bear in sliding manner against the bearing surface 7 of the horizontal link 2 a on the end limb 5 or 6 in question. The radius r of the bearing surfaces 7 is chosen to complement the radius R, with the result that both radii r, R can attain a good bearing supported on one another rotationally movable in the sense of a swivel joint.
[0058] The lateral projections f in the case of the supporting surfaces 8 of the vertical link 2 b as well as the total width d of the supporting surfaces 8 and also the distance e between the lateral boundary surfaces 9 and 10 are chosen in the case of the vertical link 2 b such that an unimpeded interlocking of vertical links ( 2 b ) and horizontal links ( 2 a ) is achieved.
[0059] As FIG. 6 shows, the bulges 16 widening the supporting surface 8 laterally and protruding over the lateral boundary surfaces 9 and 10 are formed substantially along the entire curved course of the end webs 5 and 6 .
[0060] These lateral projections b and f from bearing surfaces 7 and supporting surfaces 8 beyond the lateral boundary surfaces 9 , 10 of the end webs 5 , 6 thus provide a significant enlargement of the effective bearing surface compared with the case of pure round steel links, wherein the design of these bearing surfaces 7 and 8 in the case of the horizontal links 2 a and the vertical links 2 b in the form of cylindrical surfaces 7 and 8 that slide on one another and are supported against one another not only creates a much larger wear volume than in the case of round steel chain links, but moreover the friction ratios resulting in the case of cylindrical friction surfaces, with a local speed distribution that is completely uniform over the width of the friction surface, also result in particularly favorable friction conditions. The enlargement of the effective bearing surface compared with chain links with pure circular cross-sections also yields, when a particular tensile load applies, a reduced surface pressure inside this joint bearing compared with the case of a pure round steel chain, which is likewise favorable with respect to the wear properties of a joint formed in such a way.
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A chain has alternating vertical and horizontal chain links and with each link having an oval profile. The vertical links having an end web supporting surface formed on its inside that engages with a complementary bearing surface on the end web of adjacent horizontal link. The supporting surfaces and the bearing surfaces of all end webs are widened beyond two lateral surfaces of the respective end web, and supporting surfaces and bearing surfaces associated with one another are formed in each case as complementary cylindrical surfaces extending between longitudinal limbs. A method for producing such, closed profile chain links are hooked into open profile chain links and then the latter are closed by welding. And wherein, all supporting surfaces and bearing surfaces associated with one another are formed in each case as cylindrical surfaces that complement one another.
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This application is a Divisional application of U.S. patent application Ser. No. 09/943,927, filed on Aug. 31, 2001 now U.S. Pat. No. 6,673,119, of WILLIAM C. KIMBRELL for CHEMICAL MODIFICATION OF HYDROLIZABLE POLYMER-CONTAINING TEXTILE ARTICLES.
BACKGROUND OF THE INVENTION
This invention relates to a process for chemically modifying textile articles which contain hydrolizable polymers to reduce pilling tendency.
Hydrolizable polymers, such as polyester, possess many attributes that lead to their use for many items of commerce, such as fibers, films and molded products. Among these attributes are strength and toughness of the products, lack of reactive surface groups that can lead to staining, and various other advantages. However, many of these attributes can become problematic for certain end uses of the polymers. For example, the tenacity and other strength properties of the hydrolizable polymers such as polyester contribute to their outstanding performance as textile fibers and various other applications, such as films. However, this same strength characteristic can result in a phenomenon known as pilling if this fiber is manufactured, for example, into a spun yarn or in the manufacture of certain microdenier yarns.
Pilling results from fibers being pulled out of the fiber bundle and becoming entangled into a “ball” due to mechanical action, such as rubbing that, for example, fabrics encounter during normal use. Fabrics composed of cellulosic fibers experience similar action, but because the fiber is much weaker, the “pill balls” tend to break off before they become objectionable. These “pill balls” are a detriment to the appearance and comfort of textile articles. Reducing or eliminating the pilling propensity of hydrolizable polymer-containing textile articles would typically extend the useful life of the end-use product, such as a garment, by retaining its original appearance and comfort. Various products introduced by the fiber producers, such as low pill T-351 Trevira® polyester fiber from Hoechst-Celanese, have resulted in some degree of success in reducing pilling tendency. U.S. Pat. No. 3,104,450 to E.I. du Pont de Nemours and Company suggests that by controlling the relative viscosity and the break elongation of polyester fibers, one can reduce the pilling tendency of fabrics containing those spun polyester yarns.
Two major disadvantages are typically associated with fiber modifications made by the fiber producers in attempting to resolve the pilling issue. First, if the fiber producer lowers the fiber strength to the level required for good resistance to pilling, it becomes difficult for the yarn manufacturer to spin the yarn without excessive breaks and resulting off-quality. This necessitates further treatment to adequately reduce the yarn strength, such as alkaline hydrolysis after fabric formation or in a subsequent laundering step, to provide good resistance to pilling. Second, due to the vast number of fiber options (such as denier, cross-section, staple length, etc.) desired in the market, the fiber producer experiences cost, quality, and capacity issues associated with the spinning of small quantities of specialty fibers.
Textile manufacturers face a multitude of challenges in attempting to resolve the pilling issue on textile articles containing hydrolizable polymers. For example, textile chemists have applied binders to increase the force required to remove fibers from the fiber bundle; however, this typically results in detrimental changes to the feel of a fabric, and the effect is generally reduced by washing the fabric or end-use product (i.e. a garment). Some effort has been devoted to lowering the fiber strength by various chemical treatments. Hydrolysis with, for instance, sodium hydroxide does indeed lower the fiber strength, but it is difficult to precisely control this process and the resulting fabric also undergoes a significant weight loss. Aminolysis of the ester linkage of the polymer, such as addressed by Farmer in commonly-assigned U.S. Pat. No. 4,103,051, incorporated by reference herein, indeed can achieve the desired properties in many instances, but also can adversely affect the dyeing of the resulting fabric. This disadvantage is addressed by commonly-assigned U.S. Pat. No. 6,113,656 to Kimbrell which discloses a method for improving the dyeing of fabric treated with the Farmer chemistry. In addition, the structure of the amines disclosed by Farmer, especially those preferred by Farmer, can lead to chemical handling issues in textile finishing facilities (as will be discussed further herein) and also to quality issues resulting from attempting to handle such chemicals. Furthermore, it has proven difficult to control the batch to batch variation, within a somewhat narrow range, on certain styles, which in turn, leads to significant treated yardage that is not acceptable, either due to poor pilling performance or excessive strength loss.
More specifically, Farmer describes in U.S. Pat. No. 4,103,051 that organic amines are a particularly preferred class of compounds for this type of reaction, resulting in generally good control of the degree of pilling improvement obtained. Farmer discloses the use of aliphatic amines containing at least 10 carbon atoms. In addition, Farmer states that fatty diamines such as n-coco-1,3-propanediamine, are the preferred amines for this process.
It has been found that the use of the above-mentioned fatty diamines can impart detrimental variability to the textiles treated by this process. First these fatty diamines, especially those containing greater than 10 carbon atoms, tend to solidify at or around room temperature. This necessitates special storage and handling requirements in a typical textile dyeing operation such as, for example, drum heaters or other heating equipment to maintain the amine at a temperature above its melting point. Second, these compounds, such as the n-coco-1,3-propanediamine preferred by Farmer, are mixtures of unbranched carbon chains containing from 8 to 18 carbon atoms. This mixture tends to separate according to the size of the carbon chain resulting in unacceptable variations of the chemical composition and the degree of strength reduction obtained by this process. This again leads to special chemical handling requirements to minimize this potential variable, such as the use of drum mixers. Finally such diamines are known to adsorb and react with carbon dioxide from the air, resulting in an insoluble carbamate that does not react with polyester or other hydrolizable polymers. Without special attention to controlling the exposure of these amines to the air, various mixtures of products result. The net result can be less than the necessary amount of active amine being used to obtain the required strength reduction necessary to achieve good pilling performance. All of these potential chemical variations result in a process that can be very difficult to control within acceptable product performance tolerances.
SUMMARY OF THE INVENTION
In light of the foregoing discussion, it is one object of the current invention to achieve a textile article, which contains hydrolizable polymers that have been chemically modified by branched chain amine treatment, that has consistently good pilling and acceptable strength characteristics. A textile article includes fiber, yarn, fabric, film, etc. or any combination thereof. The textile article may be dyed or undyed. As used herein, a hydrolizable polymer is or includes any polymer that is capable of undergoing a hydrolysis reaction, such as, for instance, polyester. The term hydrolysis is used herein to include any reaction that typically results in the cleavage of the ester linkage in the polymer. Without being bound by theory, it is believed that this cleavage is the mechanism by which the textile article is weakened and improved resistance to pilling is obtained. Hydrolysis can include the addition of water, resulting in the re-formation of carboxylic acid and alcohol moieties, and can include a reaction with acids or bases. If amines are utilized, the resulting decomposition products are an alcohol and an amide. Hydrolysis reactions can also occur with polymers such as wool, such that an amide linkage is cleaved. However, this reaction typically requires more robust treatment conditions such as increased temperature, increased amine concentration, etc.
By good pilling, it is meant that the article achieves a minimum 3.0 rating after 30, 60, or 90 minutes when tested for Random Tumble Pilling according to ASTM test method D 3512-99A and is typically dependent upon the composition of the article being treated, the method of manufacture of the article, the amine used for treatment, etc. The amount of strength that will generally be considered to be “acceptable” is the strength required for the treated article to function within its anticipated end product for a minimum number of use or wear cycles, which will generally also include intermittent cleaning cycles as well. The strength that is considered to be acceptable for a given article will therefore vary depending on the type of treated article, how it will be used in an end product, the type of end product, etc. By way of example, acceptable strength for an article intended for use in knit shirting is achieved with a minimum 50 pound rating when tested for Mullen Burst Strength according to ASTM test method D 3786-87. More specifically, by experience it has been determined that a certain double knit (24 gauge) 100% polyester tuck fabric to be used in knit shirting should have strength of about 50 pounds, but no more than 90 pounds, when tested for Mullen Burst Strength according to ASTM test method D 3786-87, and preferably, between 55–65 pounds. If the Mullen Burst Strength exceeds 65 pounds, unacceptable pilling performance is obtained on this particular style. If the Mullen Burst Strength drops below 50 pounds, the fabric is generally considered to be too weak for apparel applications and holes may be punctured into the garment during normal use conditions.
As an ASTM test method, Mullen Burst Strength is typically used for determining the strength of knit or non-woven fabrics. If the treated fabric is a woven fabric, or if fibers or yarns are modified by the process of the current invention, other methods for determining the strength of the textile article must generally be used. By way of example, these methods include determining the tear strength of a woven fabric or determining the tensile strength of the fibers or yarns using test methods which are known and available to those skilled in the art.
Similarly, other standard methods for evaluating the pilling resistance of fabrics or fibers and yarns exist and may be used. By way of example, these methods include Brush and Sponge, Martindale and Elastomeric Pad methods which are known and available to those skilled in the art.
A second object of the current invention is to achieve a textile article, which contains hydrolizable polymers that have been chemically modified by branched chain amine treatment, that maintains its aesthetic appearance and comfort properties due to its improved resistance to pilling. The formation of “pill balls” leads to an unsightly appearance of the article. In addition, these “pill balls,” when found in a garment, for example, generally result in a loss of garment comfort due to the abrasive nature of these protrusions against the skin. Therefore, reducing or eliminating the formation of “pill balls” allows for the extension of the useful life of textile articles, such as apparel, made from hydrolizable polymer-containing fabric.
It is also an object of the current invention to achieve a method for modifying textile articles, such as fabrics containing hydrolizable polymer fibers and/or yarns, with branched chain amines to reduce their propensity to pill while at the same time maintaining acceptable strength characteristics. The chemical structure of these amines improves both the process of modifying the hydrolizable polymer-containing textile articles and reduces or eliminates certain quality and cost issues associated with variations in this process. These variations are believed to be caused by the chemical compositions of amines disclosed in the prior art and the chemical handling procedures typical in a textile dyeing and finishing operation. This method also generally reduces the process and product variability associated with the prior art.
It is another object of the current invention to achieve a substituted hydrolizable polymer wherein the substitute is a branched chain amine. It is generally believed that this polymer is a reaction product that is formed after the textile article has been treated with the branched chain amine.
Other objects, advantages, and features of the current invention will occur to those skilled in the art. Thus, while the invention will be described and disclosed in connection with certain preferred embodiments and procedures, such embodiments and procedures are not intended to limit the scope of the current invention. Rather, it is intended that all such alternative embodiments, procedures, and modifications are included within the scope and spirit of the disclosed invention and limited only by the appended claims and their equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a scanned image of an untreated sample of 100% double knit (24 gauge) polyester fabric showing the pill balls observed on the fabric when tested for Random Tumble Pilling according to ASTM test method D 3512-99A for 90 minutes.
FIG. 1B is a scanned image of a sample of the same fabric of FIG. 1A , but which was treated with isotridecyloxypropyl-1,3-diaminopropane, a branched chain alkyl amine according to the present invention, showing the lack of pill balls on the surface of the fabric when tested for Random Tumble Pilling according to ASTM test method D 3512-99A for 90 minutes.
DETAILED DESCRIPTION OF THE INVENTION
A textile article that contains hydrolizable polymer is provided that has been chemically modified to achieve a useful change in certain of its properties. The textile article may be a chemically modified fiber, yarn, fabric, film, etc. or any combination thereof, and the fiber or yarn may be used to manufacture a fabric. The fibers used to manufacture the yarns or fabrics can have any cross-section or any of the deniers commonly used for textile applications. By way of example, this would include round or multi-lobal cross-sections and deniers ranging from about 5 denier to less than 1 denier (namely, microdenier fibers) and can also include splittable (or bi- or multi-component) microfibers. By splittable microfibers, it is meant to include fibers co-extruded from two or more polymers that can be separated by chemical and/or mechanical treatment to yield two or more fibers of lower denier than the fiber that was initially extruded. Such chemical treatments may or may not result in the dissolution of some of the initial fiber material (as in the standard islands-in-the-sea type fibers).
Any hydrolizable polymer can be modified by treatment according to the invention, under the appropriate conditions, with ammonia or organic amines. By way of example, hydrolizable polymers include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytriphenylene terephthalate, other polyesters, wool, polylactic acid based polymers, and the like, and any combination thereof. As previously discussed, in the example of polyester, aminolysis of the ester linkage is believed to be the mechanism of reducing the polymer strength and thereby improving the resistance to pilling. Such aminolysis generally results in the formation of amide groups within the polymer chain by incorporation of the amine utilized in the reaction. These amide groups may be located on the surface of the fiber or anywhere within the fiber cross-section depending on the reaction conditions employed.
In addition, hydrolizable polymer-containing articles that have been chemically modified according to the present invention may be dyed using conventional textile dyeing procedures. The resulting dyed article is typically substantially spot-free and generally exhibits evenly distributed dye throughout the article.
In one practice of the present invention, a fabric containing certain polyester fibers is treated with certain branched chain amines prior to dyeing. Without wishing to be bound by any theory, such amines are believed to reduce the strength of the polyester fibers by aminolysis of the ester linkage of the polymer as previously discussed.
The fabrics of the current invention may be constructed from 100% spun polyester yarns, 100% microdenier filament polyester yarns, blends of spun and filament polyester yarns (which may be microdenier or non-microdenier filament yarns), and blends containing other fiber types, such as polyester and cotton blend fabrics. Suitable blends may contain, in addition to polyester fibers (which may be filament or staple fibers), other synthetic fibers, such as polyamides, polyolefins, polyacrylics, and regenerated cellulose fibers. Suitable blends may also incorporate other natural fibers, such as cotton, wool, linen, and flax. The fabrics of the current invention may be of any variety, including but not limited to, woven fabrics, knit fabrics, or non-woven fabrics or combinations thereof. They may optionally be colored by a variety of dyeing techniques, such as high temperature jet dyeing with disperse dyes, thermosol dyeing, pad dyeing, transfer printing or any other technique that is common in the art for comparable, equivalent, traditional textile products. If yarns or fibers are treated by the process of the current invention, they may be dyed by suitable methods prior to fabric formation, such as for instance package dyeing, or after fabric formation, or they may be left undyed.
The present invention discloses the use of certain branched chain amines that will reduce the hydrolizable polymer strength to a level required for acceptable resistance to pilling for textile applications, will reduce or eliminate all of the previously discussed potential chemical variations, and does not necessitate special storage and handling requirements. The amines are preferably chosen from the group consisting of aliphatic amines, alkyl amines, aliphatic substituted cyclic amines (as long as the substituent does not exhibit an electron withdrawing effect that renders the amine less reactive) and diamines or polyamines of the above-mentioned amine classes. The alkyl amines may be isodecyloxypropyl-1,3-diaminopropane, isododecyloxypropyl-1,3-diaminopropane, or isotridecyloxypropyl-1,3-diaminopropane.
The amines generally contain from 8 to 14 carbon atoms with a branched chain. Typically, the branch occurs at the third carbon atom. Other branched chain amines can be used, but preferably the substituent is not a mixture of products having a tendency to separate from each other (which can cause the consistency problems). It is preferable that substantially all of the branched chain amines have a molecular weight that varies by less than 42 atomic units both before and after the chemical reaction with the polymer. It is also preferable that the amine is a liquid within the range of temperature found in a typical textile dyeing facility. Substituted amines of this type generally have a substantially lower solidification temperature, such as below room temperature.
In addition, the branched chain reduces or eliminates the adsorption of carbon dioxide and the resulting carbamate formation. Without being bound by theory, it is believed that the branched chain provides a stearic hindrance to such carbamate formation. Also within this class of amines, one can obtain pure C 8 to C 14 substituents unlike the mixtures obtained with other classes of amines. This property reduces or eliminates the potential for separation of the chemical into its various fractions and also leads to more uniform reaction kinetics. All of these properties result in a chemical that is very consistent, despite day to day variations that can be expected in a textile dyeing facility. Accordingly, a more consistent, modified hydrolizable polymer-containing product is produced that repeatedly achieves good pilling performance and exhibits acceptable strength characteristics for its intended end-use. This is achieved even when the strength requirement for acceptable pilling approaches the minimum strength requirements dictated by the product end-use which, for example, may be an apparel garment that does not contain any holes or is not easily torn.
The concentration of the amine used to treat textile articles can be varied within a broad range, depending on the amount of degradation required to achieve acceptable pilling performance, and is related to the inherent strength of the textile article to be processed. The chosen amount of amine typically is between about 0.05% and 5% on weight of the article to be treated. Generally, this range is between about 0.10% and 1% on weight of the fabric. In other instances, this range is between about 0.20% and 0.70% on weight of the fabric to be treated. The inherent strength of the fiber, which will ultimately be treated with the amine, generally varies between different manufacturers of the fiber and between fiber types. As a result, this characteristic typically needs to be examined in determining the concentration and amount of amine to be used for a given treatment. As stated previously, the controlling factors that determine the amount of amine necessary are the inherent strength of the fiber, the amount of strength degradation required to achieve acceptable pilling performance for the particular product, and the lower limit of strength acceptable for the end-use of the article.
In one aspect of the invention, the process of the current invention requires no special equipment; standard textile dyeing and finishing equipment can be employed. By way of example, a textile fabric may be treated either in a batch operation, wherein chemical contact is prolonged, or in a continuous operation, wherein chemical contact with the fabric is shorter. Generally, a predetermined amount of the desired chemical is deposited onto the hydrolizable polymer-containing article, and the treated article is then exposed to a sufficient amount of heat for a predetermined amount of time, as will be discussed further below. The application of the chemical to the hydrolizable polymer-containing article may be accomplished by immersion coating, padding, spraying, foam coating, or by any other technique whereby one can apply a controlled amount of a liquid suspension to an article. Employing one or more of these application techniques may allow the chemical to be applied to a textile article in a uniform manner. As noted above, once the chemical has been applied to the article, the article is subjected to heat to obtain the desired reaction between the chemical and the article. A typical time and temperature relationship follows for this reaction. As the temperature is increased, the reaction time will generally decrease. For example, suitable temperatures for polyethylene terephthalate will generally range from about 180 to about 400 degrees F., and exposure times will typically range from about 1 to about 90 minutes. Heating can be accomplished by any technique typically used in manufacturing operations, such as dry heat from a tenter frame, microwave energy, infrared heating, steam, superheated steam, autoclaving, etc. or any combination thereof.
One process that has been found acceptable involves placing a textile fabric to be treated into a high temperature jet dyeing machine charged with dye liquor, adding the appropriate amount of a branched chain amine, heating the dye jet to a predetermined temperature, holding the temperature for a certain amount of time, cooling the machine to a lower temperature, dropping the liquor out of the dye jet, and finally rinsing the fabric with water, then acetic acid, and water again to remove any unreacted amine from the fabric surface. While acetic acid is commonly used in textile dyeing operations, other acids of similar nature, such as citric acid or formic acid could be used. In an alternative embodiment of the current invention, a small amount of a strong base, such as sodium hydroxide, is added to the amine treatment. This addition maintains a high pH in the dye liquor and thereby assists in forcing the reaction to proceed to completion, theoretically by decreasing the solubility of the amine in water, which increases the affinity of the amine to the fabric so the chemical reaction can occur. Adding dyes and auxiliary chemicals to the dye machine and dyeing the fabric can follow this treatment by suitable dyeing processes. Alternatively, with the appropriate dye selection, one can amine treat and dye the hydrolizable polymer-containing article in one step, or one could amine treat the article following the dyeing process.
As mentioned previously, a substituted hydrolizable polymer, wherein the substitute is a branched chain amine, is produced as a result of the chemical reaction that occurs between the hydrolizable polymer contained in the textile article undergoing treatment and the amine. The amine is comprised essentially of hydrogen, nitrogen, and carbon atoms, but it may, in some instances, further comprise oxygen atoms. During the aminolysis reaction that occurs between the polymer and the amine, some of the ester linkages of the hydrolizable polymer are cleaved by the branched chain amine molecule. The product of the reaction is typically an amide and an alcohol. The resulting substituted hydrolizable polymer may be in the form of a textile article such as a fiber, yarn, fabric, film, or any combination thereof. By way of example, a fabric containing this polymer may be incorporated into an article of apparel, bedding, commercial upholstery, residential upholstery, or automotive upholstery.
The following examples illustrate various embodiments of the present invention but are not intended to restrict the scope thereof. In the examples, all parts and percentages are by weight on the fabric unless otherwise noted.
Unless otherwise stated, all examples utilize fabric comprised of double knit (24 gauge) 100% polyester tuck construction. The fabric contains 29.16% 36.0/1 T-472 ring spun polyester yarns, 44.31% 27.0/1 T-472 ring spun polyester yarns and 26.53% 1/070/100 56T Danbury microdenier polyester yarns. The staple fiber T-472 is commercially available from Wellman, Inc. of Charlotte, N.C.; the microdenier polyester yarn 56T is commerically available from E.I du Pont de Nemours and Company of Wilmington, Del. The fibers were collectively spun into yarn by Milliken & Company of Spartanburg, S.C. Pilling is determined by ASTM D 3512-99A Method for Testing Random Tumble Pilling. Strength is determined by ASTM D 3786-87 Method for Testing Mullen Burst Strength.
EXAMPLE 1
The following example shows treatment of the polyester fabric with n-coco-1,3-propanediamine, a fatty diamine.
A 100 gram piece of fabric was placed into a Werner Mathis laboratory jet dye machine. Two liters of water, containing 0.75 grams of n-coco-1,3-propanediamine (Duomeen® CD from Akzo Nobel Surface Chemistry of Chicago, Ill.) and 0.50 grams of sodium hydroxide was added to the dye vessel. The dye vessel was sealed and heated to 266 degrees F. This temperature was maintained for 30 minutes, then the dye vessel was cooled to 160 degrees F. and emptied. The fabric was then rinsed with water, rinsed a second time with water containing 1.0 gram of acetic acid, and rinsed once more with water. The acetic acid was present to dissolve any residual, unreacted amine from the surface of the treated fabric. The treated fabric was subsequently dyed with a disperse dye, rinsed with water, and then dried and heat set following procedures that are known in the art. The Mullen Burst Strength and Random Tumble Pilling of the fabric was then measured and compared both before and after dyeing. This example was repeated 2 times. The results are shown in Table 1 and FIG. 1A .
EXAMPLE 2
Example 1 was repeated, except that in place of the n-coco-1,3-propanediamine, isotridecyloxypropyl-1,3-diaminopropane (available from Tomah Products, Inc. of Milton, Wis.), a branched alkyl amine according to the present invention, was used. This example was also repeated 2 times. The results are also shown in Table 1 and FIG. 1B .
TABLE 1
Comparison of n-coco-1,3-propanediamine to isotridecyloxypropyl-1,3-
diaminopropane
Mullen Burst Strength
Random Tumble Pilling
Example
(Pounds)
30 min.
60 min.
90 min.
1A
81
3.5
3.0
3.5
1B
90
2.5
3.0
4.0
1C
83
3.0
4.5
4.5
Average
85 +/− 5
3.0
3.5
4.0
1A: Dyed
77
4.5
4.5
4.5
1B: Dyed
76
4.5
5.0
5.0
1C: Dyed
77
4.0
4.5
4.5
Average
77 +/− 0.7
4.3
4.7
4.7
2A
83
4.0
4.5
4.5
2B
78
3.0
5.0
4.5
2C
83
3.0
4.0
4.5
Average
81 +/− 3
3.3
4.5
4.5
2A: Dyed
83
4.5
4.5
4.5
2B: Dyed
78
4.0
4.5
4.0
2C: Dyed
76
4.5
4.5
4.0
Average
79 +/− 4
4.3
4.5
4.2
Untreated
127
1.0
1.0
1.0
Two observations could be made regarding the data in Table 1. First, the batch to batch variation of the treatments was lower for the isotridecyloxypropyl-1,3-diaminopropane than for the n-coco-1,3-propanediamine treatments. Second, the amine reaction was essentially complete for the isotridecyloxypropyl-1,3-diaminopropane before the dyeing process. This typically indicates that this amine has been essentially consumed, whereas the n-coco-1,3-propanediamine sample contained residual, unreacted amine when the dye cycle began. This can lead to dye stains on the fabric due to the unreacted amine being exuded from inside the fabric and subsequent complexation with the dyestuff in the aqueous dye liquor. Both factors indicate the obvious benefits of the branched chain amine over the straight amine.
EXAMPLE 3
The following example shows how exposure to ambient air affects the state of matter for the fatty diamine by changing it from a liquid to a solid due to adsorption of carbon dioxide.
Approximately 2 grams of n-coco-1,3-propanediamine was exposed for two hours to the airflow under a laboratory hood. Essentially the entire product was changed from a clear liquid to a white waxy solid due to the adsorption of carbon dioxide from the air. When the same chemical was exposed for two hours under a dry nitrogen stream (i.e. a carbon dioxide free environment), it remained unchanged.
The above experiment was repeated with isodecyloxypropyl-1,3-diaminopropane, an amine of the present invention. No change was observed in the appearance of the chemical in either the air or dry nitrogen environments.
When the laboratory hood air exposed samples and samples directly from the container of n-coco-1,3-propanediamine were examined by a Hewlett Packard 6890 Gas Chromatography/Mass Spectroscopy machine, the only significant finding was an increase in the peak heights of the laboratory hood samples which generally indicates a greater mass of the chemical being detected. Since it is known that this amine will adsorb carbon dioxide from the air and react to form an insoluble carbamate, it is believed that only the carbamate is being detected. Due to the reaction rate, it is difficult to isolate the pure starting material by this technique. While techniques exist that should allow one to determine the percentage of amine that was converted to carbamate, these techniques were not investigated.
EXAMPLE 4
The following example shows how exposure of the amine to air affects the strength of the treated fabric.
Examples 1 and 2 were repeated 2 times each, except the amine in each case was intentionally exposed to the air for 2 hours before the treatment was performed. The results of this exposure to carbon dioxide in the air are shown in Table 2.
TABLE 2
Effect of Chemical Exposure to Air on Fabric Strength Loss
Average Mullen Burst
Example
Sample
Strength
1A
Duomeen ® CD
83
1B
Duomeen ® CD:
89
Exposed to Air
2A
Isotridecyloxypropyl-1,3-
90
diaminopropane
2B
Isotridecyloxypropyl-1,3-
91
diaminopropane: Exposed to Air
Table 2 shows that exposing Duomeen® CD to the ambient air generally increases the strength of the chemically treated product which, for the purposes of the present invention, adversely affects the pilling tendency of the fabric by making it harder for the pill ball to break away from the fabric. However, the fabric treated with isotridecyloxypropyl-1,3-diaminopropane does not show significant changes in its strength characteristic, and thus, exposure to the carbon dioxide in the ambient air does not detrimentally affect the pilling tendency of the treated fabric. This observed condition can be even more extreme in a production dye facility due to typical seasonal changes in temperature, humidity, airflow rates, and other chemical handling variables.
The above description and examples show that the present invention provides a novel method for reducing the pilling tendency of hydrolizable polymer-containing textile articles. Accordingly, the invention has many applicable uses for incorporation into articles of apparel, bedding, residential upholstery, commercial upholstery, automotive upholstery, and any other article wherein it is desirable to manufacture a product with reduced pilling tendency.
These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the scope of the invention described in the appended claims.
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A hydrolizable polymer-containing textile article and method for producing the same is provided that has been chemically modified by treating the article with certain branched chain amines to reduce the strength of the fibers contained therein, thus rendering the article less prone to the formation of objectionable pill balls, thereby increasing wearer comfort and retaining the desired appearance of the article, and thereby extending the useful life of the article.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to sunshields and specifically to automobile sunshields or shades. The sunshield of the present invention may be positioned against an interior window surface, such as the windshield, to act as a barrier and protect the interior of the motor vehicle against sun rays. This thereby reduces undesired weathering caused by sun rays and reduces the heat which tends to build up within the vehicle interior.
2. Description of the Prior Art
In general, prior art automobile sunshields may be positioned to shield the interior of the vehicle from either an interior or exterior location. As an example, interior sun shades include a folding cardboard windshield shade such as shown in the patent to Levy U.S. Pat. No. 4,202,396. Another type of interior windshield shade is a fan-like venetian blind of the type shown in Surtin U.S. Pat. No. 4,332,414, or Maguire U.S. Pat. No. 4,606,572. These types of interior shades have had certain difficiencies. For example, the folding cardboard shades are bulky when folded and difficult to store. When opened, the cardboard shades tend to return to the folded position thereby not providing for a complete covering of the windshield. The fan-like venetian blind shades are usually mounted semi-permanently and are awkward to use, expensive in cost and again, do not provide for a full coverage of the windshield when opened to the full position.
In addition to the interior shades, exterior screens may also be used and for example, may consist of a thin layer of fabric or plastic to lie on the exterior surface of the windshield. This type of structure is of course subjected to the elements and can quickly become dirty or damaged thereby requiring frequent replacement. In addition, films have been applied to the windshield, but such films can not legally obstruct the driver's vision so that the films cannot be opaque enough in order to adequately protect the interior of tthe vehicle from the sun's rays.
The various existing sunshields, including the folding boards, fan-like venetian blinds, films and screens have not been successful in providing for all of the necessary requirements for a sunshield or shade. Specifically, these requirements are a high blockage of the suns rays and ease of use and a compact size when not in use for ease of storage. The present invention, therefore, provides for an improvement over the prior art sunshields and provides for a high blockage of the sun's rays, a simplicity of structure, ease of use and a very compact size when collapsed for storage.
SUMMARY OF THE INVENTION
In order to accomplish the objects of the present invention, a sun shade is constucted of two flexible circular loops which are positioned adjacent each other. The loops are covered by a sheet fabric material. Specifically, the loops may be enclosed within shaped openings that are formed within the fabric material. For example, the fabric material may include a pair of sheets of fabric material which are attached together at particular positions to provide for the defined adjacent openings to receive the flexible circular loops.
The use of the two side by side loops covered by fabric creates a broad elliptical screen in the fully extended position for the sunshield of the present invention. Therefore, the sunshield in the extended position may be located adjacent a window, such as the windshield of the automobile, and with the sunshield maintained in position by portions of the automobile such as window trim, visors and rear view mirror. The sunshield may be positioned adjacent other windows such as the rear window or side windows using an appropriate holding device. Since each of the loop members and associated sheet fabric material is independent from the other, the sheet fabric material between the loops can, therefore, fold and bend in a central position like a hinge. This allows for the shield in the fully extended position to easily adapt to different size and shaped windows and can accommodate and substantially cover these windows to block the suns rays.
When it is desired to remove the sunshield and store it for later use, the two fabric covered loop members are folded one on top of the other at the fabric hinge to reduce the structure in half. The two loops now may be twisted and twisted into a configuration so that the structure collapses upon itself to form a much smaller series of concentric loops and layers of fabric. The size of the entire sun screen may then be reduced to circular members less than a foot (1'') in diameter and preferably less than ten inches (10") in diameter so that the sunshield in its collapsed state may be very easily stored.
In addition to the above, the sunshield of the present invention provides for a device having a reflecting surface to reflect the sun's rays to thereby protect the automobile interior and to subsantially reduce heat buildup within the vehicle. In addition, the present invention is simply in construction so that it may be economically manufactured and relatively low in cost. Because the sunshield of the present invention in its extended size is large, but in its collapsed state is relatively small, this enhances the usability of the device since it can be stored in an easily accessible position, such as in a side pocket of the automobile door or under the car seat. Because the device of the present invention uses sheet fabric as the outer surfaces, it is apparent that this fabric may be attractively printed or woven so that the sunshield can have a desirable attractive appearance when in use.
The collapsing aspect of the flexible loops, is similar to the method of folding and storing bandsaw blades for packaging and storage. In addition, a cloth hat currently sold in the Orient also includes a similar flexible circular member which can fold together to provide for storage. However, these devices incorporate a single flexible loop having only a circular shape when in the expanded position, whereas the present invention provides for a pair of such flexible circular loops, each covered in fabric and joined together so as to produce for the broad elliptical shaped shield when in the extended position. Although the twisting and folding of the present invention is similar to the bandsaw blades and Oriental cloth hat, the present invention provides for an additional complexity in folding together two or more flexible loops and twisting and folding these loops simultaneously so as to collapse all of the loops and the fabric into a small size structure.
BRIEF DESCRIPTION OF THE DRAWINGS
A clearer understanding of the present invention will be had with reference to the following description and drawings wherein:
FIG. 1 is a elevational view partially broken away showing an automobile sunshield or shade of the present invention illustrating the internal loop frame structure;
FIG. 2 is a perspective view of the sunshield the present invention in position behind an automobile windshield;
FIG. 3 is a side view of the sunshield and the windshield both in a partially deflected position for either placement or removal and in a fully extended position for shielding;
FIG. 4 is a elevational view showing the sunshield along the side view of the vehicle;
FIG. 5 is an elevational view showing the sunshield in the rear window of a vehicle;
FIG. 6 is a second embodiment of the sunshield having truncated sides with rounded corners relative to the embodiment shown in FIG. 1;
FIG. 7 is an elevational view of a third embodiment similar to the embodiment of FIG. 1, but additionally showing flap portions and accessory attachment loops and also illustrating how a portion of the fabric may be cut away;
FIG. 8 is an elevational view of the present invention illustrating additional loop members;
FIG. 9 is a sectional view through a midpoint of one of the loop members illustrating the use of two layers of fabric;
FIG. 10 is a fragmentary perspective view illustrating the use of a single layer of fabric with the loop members;
FIG. 11 is a cross sectional view of a sliding attachment for the ends of the loop members;
FIGS. 12(A) through 12(F) illustrate the operation of the sunshield of the present invention showing how it may be folded up for compact storage; and
FIG. 13 illustrates a single loop member in the folded up position illustrating how each single loop member is folded to provide for three loop portions to thereby substantially reduce the size.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a sunshield 20 is formed by a pair of resilient loop members 22 forming frames. The loop members are retained in position by a peripheral loop portion of fabric 24 which includes an internal loop retaining structure 26. Located between the loop retaining structues 24 and 26 is an interconnecting fabric 28 or hinge portion. The fabric 28 is not in tension, but the fabric portion 32 within the loop members 22 may be in tension. As an example, the internal loop structure 26 may be provided by mechanically fastening (stitching), fusing, or gluing so that the loop frame members 22 are retained in position. A retaining member 34 may be attached at one end of the sunshield. Also, a bag can be used to store the sunshield in the collapsed state if desired. Also as shown in FIG. 1, the flexible loop frame 22 may be formed of a flexible material such as flexible steel and with the ends held together by a retaining clip 46.
Although the loops 22 are described as formed of flexible steel, other materials such as plastics may be used. The term fabric is to be given its broadest meaning and may includes woven fabrics, sheet fabrics or even films.
As shown in FIG. 2 the sunshield 20 may be positioned behind a windshield 82 of a vehicle 60. The windshield is held in position by a window frame 64 and the sunshield 20 is positioned between a dashboard 70 and a roof 74 of the vehicle 60. Visors 68 and rear view mirror 62 may be used to help retain the sunshield 20 in position.
FIG. 3 illustrates a side view of the automobile illustrating the sunshield 20 in dotted position being retained behind the windshield 82 between the dashboard 70 and held in position by the visors 68 and rear view mirror member 62. In full position shown by the reference character 38, the sunshield 20 is illustrated to be bent for easy placement or removal from the windshield. It is to be appreciated that the sunshield 20 may also be left in a reclining position against the steering wheel (not shown) to provide for some protection against the sun rays, but the preferred position is as shown in dotted line in FIG. 3.
FIG. 4 illustrates the sunshield 20 of the present invention positioned against the side of the vehicle so as to block sun rays coming in through side windows 76. Similarly, FIG. 5 illustrates the sunshield 20 of the present invention positioned against a rear window 86 to block the sun's rays passing through the rear window of the vehicle 60.
FIG. 6 illustrates a second embodiment of the sunshield 20 of the present invention wherein the outer peripheral loop portions 24 have truncated sides with rounded corners. This shape may provide for a closer approximation of the windshield perimeter of some vehicles. The shape of the sunshield 20 of FIG. 6 is provided by having the internal loop frame 22 being flexible enough to follow the external fabric periphery 24. As an alternative, as shown in FIG. 7, additional flap members 36 may be formed to provide for the truncated side portions, but in the embodiment of FIG. 7, the internal loop frame 22 has a circular configuration. It can be seen, therefore, that the sunshield 20 of the present invention may take a variety of external shapes and with these external shapes, provided either by the additional of flaps such as flaps 36 to define the shape, or by having the peripheral loop portion 24 formed with the desired shape and with the internal loop frame member 22 conforming to this peripheral loop shape.
FIGS. 6 and 7 also show additional modifications that may be made to the sunshield 20 of the present invention. For example, as shown in FIG. 6, grommets 40 may be formed in the fabric, both in the nontension portion 28 and the tension portion 32 and with these addtional grommets used for the attachment of the sun screen by accessory members such as elastic members. Alternately, additional hanging loops 30 may be attached at peripheral portions around the sunshield 20 to also provide for attachment means. FIG. 7 also illustrates that if desired, the fabric such as the tension fabric 32 may be cut away, such as at positions 52 and may be attached such as through the use of rivets 54.
FIG. 8 further illustrates how the sun screen 20 may be composed of a larger number of loop members such as the use of three loop members as shown in FIG. 8.
FIGS. 9 and 10 illustrate the alternative use of either two sheets of fabric, or a single sheet of fabric. As shown in FIG. 9, which is a cross sectional view of one of the loops in the tension area 32, fabric on both sides wrap around the flexible internal frame loop member 22. The frame member 22 is, therefore, held in position within the two layers of fabric in the tension area 32. As shown in FIG. 10, a single fabric member may be either wrapped around the frame member 22, as shown by to be portion 56, or may be formed as an external tube to contain the frame 22 and with the tube 56 attached to the fabric. In either event, a single layer of fabric is used.
FIG. 11 illustrates a specific design for the retaining clip 46. It is to be appreciated that the loop 22 may be formed by bending a straight piece of material and having the ends of the straight piece held together by the retaining clip 46. The ends of the frame 22 could be held in rigid position, but as shown in FIG. 11, ends 42 and 44 of the frame 22 may be received within the retaining clip 46 to slide relative to each other. This allows for some sliding movement of the ends 42 and 44 to thereby facilitate the manufacture of the sunshield and allow for some flexibility to accomodate any changes in size within the tension loop 32.
As shown in FIGS. 12(A) through 12(F), the various steps for folding up the sunshield 20 for storage are shown. In FIG. 12(A), the first step consists of folding the two tension loop portions 32 together about the nontensioned fabric portion 28. When the two halves are folded together, the second step, as shown in FIG. 12(B), is to start to twist and fold the substantially circular structure to initially collapse the loops and fabric into a smaller diameter. As shown in FIG. 12(C), the third step is to fold in the opposite border of the circular structure upon the previous fold to further collapse the loop structure with the fabric. As shown in FIG. 12(D), the fourth step is to continue the collapsing so that the size of the collapsed structure is a fraction of the diameter of the initial loop structure. FIG. 12(E) shows the fifth step with the loops and fabric collapsed on each other to provide for a small essentially circular configuration having a plurality of concentric loop rings and layers of fabric so that the collapsed structure has a diameter which is a fraction of the diameter of the structure as shown in FIG. 12(A). The final step shown in FIG. 12(F) is to use the elastic retaining member 34 or bag to hold the collapsed structure in place.
FIG. 13 illustrates one of the loop frame members 22 in the collapsed state. As can be seen in FIG. 13, the structure essentially consists of three loop rings intertwined to lie flat. Of course, the actual sunshield 20 would have the plurality of frame members 22 collapsed together and with the fabric held in place by the collapsed loop rings. In the collapsed state, the structure would have a diameter less that twelve inches (12") and preferably less that ten inches (10"). It can be seen, therefore, that in the collapsed state the sunshield may be easily stored.
The present invention, therefore, provides for an automobile sun screen in which two or more adjacent fabric covered loops provide for an elongated shaped screen so as to conform to the shape of an automobile windshield or other window. To achieve the collapsed state, the sunshield is first folded in half and then twisted and folded further, causing the loops to collapse within themselves which forms a much smaller series of concentric loops and layers of fabric.
Although the invention has been described with reference to particular embodiments, it is to be appreciated that various adaptations and modifications may be made and the invention is only to be limited by the appended claims.
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A collapsible elongated sun sheild including, a plurality of adjacent collapsible flexible loop members. A fabric covering material for substantially covering the flexible loop members. The loop members substantially supporting the fabric in particular areas to provide for loop portions and an interconnecting portion forming a hinge between each loop portion. The loop portions of the fabric are folded on top of each other about the hinge portion to have the loop members and associated fabric overlaying each other. The overlaying loop members are collapsed by twisting and folding to form a plurality of concentric loop rings and layers of fabric to substantially reduce the size of the sunshield.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to the field of electronic circuits, and in particular to a method of measuring low impedances.
BACKGROUND OF THE INVENTION
Several factors in the development of computer systems and electronic circuits such as microprocessor chips, printed circuit boards, and electronic packaging contribute to the need for lower impedances over a wide bandwidth in the power distribution networks of these systems. Decreasing power supply levels, signal transition times and die sizes, and the steady increase of power supply currents and clock speeds all require the power distribution network to have very low impedance levels. The typical target impedance for computer systems have decreased by a factor of five every two years. Low impedance in the milliohm and sub-milliohm range is desirable to minimize noise generation, electromagnetic radiation and interference.
While techniques to verify signal integrity of high-speed signals have been widely available, the need to accurately measure very low impedances in the milliohm and sub-milliohm ranges at high frequencies remains unsatisfied. Time-domain reflectometry instruments have been used to measure power distribution network impedances. However, time-domain reflectometry measurements are not suitable for measuring milliohm range impedances due to the noise and nonlinearity of the oscilloscope used in this method. RLC (resistance, inductance and capacitance) meters cannot measure sub-ohm impedances at hundreds of megahertz frequencies. Vector network analyzers have also been used to measure circuit parameters, however they can only access exterior points of a semiconductor chip and cannot measure interior impedances. Furthermore, vector network analyzers measure impedance by supplying and forcing a current into the system, but the current cannot be pushed through the circuit uniformly and achieve satisfactory measurements. A common disadvantage of these conventional methodologies also includes the inability to obtain on-die impedance measurement during system operations.
SUMMARY OF THE INVENTION
In accordance with an embodiment of the present invention, a method comprises generating a first current level, measuring the first current level, generating a second current level, and measuring the second current level. The method further comprises alternately generating the first and second current levels repeatedly to generate a generate a periodic current waveform, and measuring the voltage at at least one port in a system a plurality of times to obtain a plurality of sets of voltage measurements. The plurality of sets of voltage measurements are averaged. The method further comprises alternately generating the first and second current levels repeatedly at a predetermined number of different clock frequencies, determining a Fourier component of the averaged voltage measurements to determine clock frequency-dependent noises, removing the clock frequency-dependent noises to generate a filtered average voltage, and determining an impedance by dividing a Fourier component of the filtered average voltage by a Fourier component of the periodic current waveform having alternating first and second current levels.
In accordance with another embodiment of the present invention, a method of determining operating impedance in a system having a microprocessor comprises executing a first plurality of computer instructions in the microprocessor operable to create a high current level in the system, measuring the high current level, executing a second plurality of computer instructions in the microprocessor operable to create a low current level in the system, and measuring the low current level. The method further comprises alternately executing the first plurality of computer instructions and the second plurality of computer instructions repeatedly to generate a periodic current waveform, and measuring the voltage at at least one port in the system a plurality of times to obtain a plurality sets of voltage measurements. The plurality sets of voltage measurements are averaged. The method comprises continually executing the first and second pluralities of computer instructions alternately at a predetermined number of different clock frequencies to determine clock frequency-dependent noises, and removing the clock frequency-dependent noises to generate a filtered average voltage, and determining an impedance as a function of frequency by dividing a Fourier component of the filtered average voltage by a Fourier component of the periodic current waveform having alternating high and low current levels.
In accordance with yet another embodiment of the present invention, a system comprises means for generating a first current level in the system, means for measuring the first current level, means for generating a second current level in the system, means for measuring the second current level, means for alternately generating the first current level and the second current level repeatedly to generate a periodic current waveform, means for measuring the voltage at, given the periodic current waveform, at least one port in the system a plurality of times to obtain a plurality of sets of voltage measurements, means for averaging the plurality of sets of voltage measurements, means for generating the first and second current levels at a predetermined number of different clock frequencies, means for determining a Fourier component of the averaged voltage measurements to determine clock frequency-dependent noises, means for removing the clock frequency-dependent noises to generate a filtered average voltage, and means for determining an impedance by dividing a Fourier component of the filtered average voltage by a Fourier component of the periodic current waveform having alternating first and second current levels.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, the objects and advantages thereof, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:
FIG. 1 is a block and schematic diagram of an embodiment of a system of low impedance measurement according to the teachings of the present invention;
FIG. 2 is a flowchart of an embodiment of low impedance measurement according to the teachings of the present invention;
FIG. 3 is a block and schematic diagram of another embodiment of a system of low impedance measurement according to the teachings of the present invention;
FIG. 4 is a flowchart of another embodiment of low impedance measurement according to the teachings of the present invention;
FIG. 5 is a plot of voltage and predicted current and voltage waveforms generated by an embodiment of the COLD, HOT and THROB algorithms according to the teachings of the present invention; and
FIG. 6 is a plot of impedance calculations generated by embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the present invention and its advantages are best understood by referring to FIGS. 1 through 6 of the drawings, like numerals being used for like and corresponding parts of the various drawings.
FIG. 1 is a block and schematic diagram illustrating an embodiment of a system for measuring low impedance according to the teachings of the present invention. For illustrative purposes, FIG. 1 shows application of a system and method of the present invention to a computer processing unit (CPU) printed circuit board 10 , a semiconductor chip package 12 residing on printed circuit board 10 , and a semiconductor die 14 inside package 12 . Ohm's law, expressed by the following is used for solving for impedance (Z) as a function of frequency:
Z ( f ) = F f ( V ( t ) ) F f ( I ( t ) )
where F f (g(t)) is the Fourier component of function g(t) at frequency f, V is voltage, I is current, and t is time. Voltage as a function of time can be accurately measured, but it is very difficult to measure variations of current at the same time. Embodiments of the present invention accomplish this task by generating a current with controllable and known features within the frequency range of interest. The generated current has a simple waveform to avoid introducing additional noise into the measurements.
Three computer algorithms operable to generate a periodic current during microprocessor operations are provided for use during impedance measurements. The current has a simple waveform such as a step or trapezoidal waveform. The computer algorithms each comprise a series of computer instructions. The first algorithm is the HOT code, which comprises a predetermined number of computer instructions, such as four integer addition assembly language instructions, to generate high power. Other computer instructions may also be used, such as integer subtraction, and logical operations such as AND, OR, NOR, XOR, etc. The second algorithm is the COLD code, which comprises a predetermined number of computer operations, such as four integer no-op assembly language instructions, to generate low power. The HOT and COLD codes produce two different constant current levels when executed, where the HOT code generates a higher current than the COLD code. The HOT and COLD codes can be combined alternatively and continuously to create a THROB code. The width of transition between HOT and COLD determines the high frequency boundary of measured impedance. Preferably, the HOT and COLD codes reside in the instruction cache of the microprocessor ready for immediate execution to avoid stalling introduced by fetching instructions. Further, it is desirable to have sufficiently long durations of HOT and then sufficiently long alternate COLD periods to reduce the low frequency boundary. This may be accomplished by introducing loops in the code.
Referring to FIG. 2 for a flowchart of an embodiment of a process for measuring low impedance 20 according to the teachings of the present invention, the HOT code is executed to generate a steady power level so that I dd (HOT) can be measured, and execute the COLD code to generate a steady minimum power level so that I dd (COLD) can be measured, as shown in block 22 in FIG. 2. I dd (HOT) and I dd (COLD) may be determined by using a voltmeter 23 coupled to a sense resistor 24 of a voltage regulator module (VRM) 25 located on printed circuit board 10 to measure the voltage drop across resistor 24 . In blocks 26 and 27 , a THROB code that alternate predetermined lengths of HOT and COLD periods is then executed, and a plurality of voltage measurements, V 1 (t), V 2 (t), . . . V n (t) between V dd and V ss (power and ground) pads 28 - 32 located on semiconductor die 14 , chip packaging 12 and printed circuit board 10 . V 1 (t), V 2 (t), . . . V n (t) are also referred to as measured voltage drop at ports 1 through port n below. Voltage V 1 (t) at port 1 is a measurement of on-chip voltage drop and is measured by using dedicated test pads specifically provided on-chip for V dd -V ss sensing. These test pads are operable to connect with an instrument such as a high-impedance active differential probe 34 . The voltage measurements are made with an oscilloscope 36 , for example, coupled to differential probe 34 .
Referring briefly to FIG. 5 , an exemplary waveform 37 for V 1 (t) is shown. In a preferred embodiment, the THROB code provides a HOT and COLD waveform 38 at a 50% duty cycle and approximately twenty microsecond (μs) period, as shown in FIG. 5. A long-term average math function, provided by oscilloscope 36 , is used to average a large number of measurements to reduce random noise, as shown in block 40 . An exemplary averaged voltage waveform 42 , the result of averaging over 25,000 oscilloscope sweeps, is shown in FIG. 5 . Random noise typically originates from sources in the operating environment of the system and is usually arbitrary and aperiodic.
Returning to FIG. 2 , in block 44 , the HOT, COLD, and THROB codes are continuously executed as shown in blocks 22 through 40 at different clock frequencies to measure the currents and voltages at those clock frequencies. By applying Fast Fourier Transform (FFT) to obtain the Fourier component of the measured voltage waveform, the periodic noise that varies with changing clock frequencies can be isolated. This clock-dependent noise is then filtered from the averaged voltage measurements, as shown in block 46 . The small periodic spikes in the waveform are caused by loop branching in the code. An exemplary filtered average voltage waveform 48 is shown in FIG. 5 . In block 50 of FIG. 2 , the impedance, Z 1i (where I=1 to n), is determined by:
Z In ( f ) = F f ( V ( t ) ) F f ( I ( t ) )
Where F f is the Fourier component of the voltage or current, and Z 11 is the impedance of the microprocessor's power supply loop, Z 12 is the transfer impedance for port 2 on electronic package while the current is predicted for port 1 , Z 13 is the transfer impedance for port 3 on electronic package while the current is predicted for port 1 , etc. An exemplary impedance waveform 52 obtained using HOT, COLD and THROB codes over a frequency range of interest is shown in FIG. 6 .
It is preferable to provide a number of different THROB codes with different periods to cover a wide frequency range. Step or trapezoidal waveform of larger periods improves measurement accuracy at lower frequencies, and smaller periods improve accuracy at higher frequencies.
FIG. 3 is a block and schematic diagram showing another embodiment of a system of low impedance measurement according to the teachings of the present invention. Rather than using computer codes HOT, COLD and THROB to generate a trapezoidal periodic current waveform, the built-in “divide-by-N” operating mode of the microprocessor chip is used to generate the requisite waveform. The microprocessor is put in reset mode by holding its reset line 52 low while the clock frequency is provided at F CLK or F CLK /N, where F CLK is dependent on the microprocessor's operating range, and N is a positive integer. The divide-by-N operating mode is accessible by using the on-chip phase-locked loop (PLL) test mode that normally occurs during the system power up sequence. The period of the trapezoidal current waveform is preferably controlled by using an external pulse generator 54 that provides a waveform at a predetermined duty cycle, such as 50%.
Referring to FIG. 4 for a flowchart of a second embodiment of a low impedance measurement process 56 according to the teachings of the present invention. In blocks 57 and 58 , the system is held at reset and the clock frequency is set at F CLK while the I dd current is measured. The system is again held at reset, but the clock frequency is set at F CLK /N while the I dd is again measured, as shown in blocks 59 and 60 . The I dd currents at F CLK and F CLK /N and the rise and fall times determine the current waveform over time, I(t). In block 62 , the system is again held at reset while the clock frequency is toggled between F CLK and F CLK /N. Using oscilloscope 36 , a plurality of voltages, V 1 to V n , are measured from various test pads 28 - 32 on semiconductor die 14 , packaging 12 , and printed circuit board 10 , as shown in block 63 . The periodic current waveform rise time may be determined by the Fourier transform of the voltage response to the current generated in the divide-by-N mode, and the inverse rise time or the fall time corresponds to the frequency of the minimum of the Fourier transform.
A long-term average math function, provided by oscilloscope 36 , is then used to reduce random noise, as shown in block 64 . In order to properly filter out random noise, a large number of oscilloscope sweeps are used in the averaging function. Random noise typically originates from sources in the operating environment of the system, and is arbitrary and aperiodic.
Thereafter in block 65 , the voltage measurements are obtained at different clock frequencies. By applying Fast Fourier Transform (FFT) to obtain the Fourier component of the measured voltage waveforms at various clock frequencies, the periodic noise that varies with clock frequency can be isolated. For example, the clock frequency can be varied from 1 megahertz (MHz) to 1 gigahertz (GHz). The clock-dependent noise is filtered from the averaged voltage waveform. In block 66 , the impedance, Z 1i (where I=1 to n), is determined by:
Z In ( f ) = F f ( V ( t ) ) F f ( I ( t ) )
Where F f is the Fourier component of the voltage or current, and Z 11 is the impedance of the microprocessor's power supply loop, Z 12 is the transfer impedance for port 2 on electronic package while the current is predicted for port 1 , Z 13 is the transfer impedance for port 3 on electronic package while the current is predicted for port 1 , etc. An exemplary impedance waveform 70 obtained using the frequency-divided-by-N methodology over a frequency range of interest is shown in FIG. 6 .
An advantage of current excitation using the divide-by-N methodology over the computer codes includes the elimination of additional noise to the measurements. One of ordinary skill in the art will appreciate that there are noises introduced by the underlying operating system or other sub-components of the system when the microprocessor is operating. Further, the computer codes themselves introduce additional noise that may distort the shape of the current waveform. To avoid random noises associated with the clock, operating system or measuring instrument, a long-term averaging of the voltage waveform using the oscilloscope is desirable, which triggers on the sharp edges of the trapezoidal waveform.
The various embodiments of the present invention described herein provide systems and methods of measuring very low impedances of power supply loops over a wide frequency range at various points on a semiconductor die, in electronic chip packaging, and on a printed circuit board.
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A method comprises generating first and second current levels and measuring the first and second current levels. The method further comprises alternately generating the first and second current levels repeatedly to generate a periodic current waveform, and measuring the voltage at at least one port in a system a plurality of times to obtain a plurality of sets of voltage measurements. The plurality of sets of voltage measurements are averaged. The method further comprises alternately generating the first and second current levels repeatedly at a predetermined number of different clock frequencies, determining a Fourier component of the averaged voltage measurements to determine clock frequency-dependent noises, removing the clock frequency-dependent noises to generate a filtered average voltage, and determining an impedance by dividing a Fourier component of the filtered average voltage by a Fourier component of the periodic current waveform having alternating first and second current levels.
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This is a divisional application under 37 CFR 1,60, of Ser. No. 07/451,392, filed 12/15/89, now U.S. Pat. No. 5,048,481 entitled "Throttle Actuator Safety Method for automated Transmission", of inventors Kwok Wah Chan, William F. Cote' and Louis E. Miller.
FIELD
This invention relates to control systems for vehicles such as trucks, and in particular for electromechanical controls that assist the driver in shifting the gears, operating the clutch, and actuating the throttle by remote control.
BACKGROUND OF THE INVENTION
Automatic transmissions of both the automatic mechanical type utilizing positive clutches and the planetary gear type utilizing frictional clutches are well known in the prior art, as are control systems for them.
Electronic control systems utilizing discrete logic circuits and/or software-controlled microprocessors for automatic transmissions in which gear selection and shift decisions are based upon certain measured and/or calculated parameters are also known. The parameters include vehicle speed (or transmission output shaft speed), transmission input shaft speed, engine speed, rate of change of vehicle speed, rate of change of engine speed, throttle position, rate of change of throttle position, full depression of the throttle (i.e. "kickdown"), actuation of the braking mechanism, currently engaged gear ratio, and the like. Examples of such automatic and semi-automatic transmission control systems for vehicles are in U.S. Pat. Nos. 4,361,060, 4,551,802, 4,527,447, 4,493,228, 4,425,620, 4,463,427, 4,081,065, 4,073,203, 4,253,348, 4,038,889, 4,226,295, 3,776,048, 4,208,929, 4,039,061, 3,974,720, 3,478,851 and 3,942,393, all of which are incorporated by reference.
Automatic control systems for controlling the engagement and disengagement of master clutches in vehicles having automated manual transmissions (AMT) are known in the prior art, as may be seen in U.S. Pat. Nos. 4,792,901, 4,493,228, 4,081,065, 4,401,200, 4,413,714, 4,432,445, 4,509,625 and 4,576,263, all of which are incorporated by reference. An example of a control system for adjusting fuel in view of throttle setting is in U.S. Pat. No. 4,493,228, which is incorporated by reference.
SUMMARY OF THE INVENTION
An object of the invention is to provide a safety method for a vehicle's throttle actuator subsystem that ascertains whether, when the driver removes his foot from the accelerator pedal, control of the fuel pump returns to the idle governor as it should, and that stops the flow of fuel if it does not.
Another object is to provide a method that monitors a throttle actuator to insure that it accurately follows throttle commands such as the position of the accelerator pedal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified block diagram of an Automated Manual Transmission (AMT) for a vehicle.
FIG. 2 is simplified block diagram of a preferred embodiment of the throttle actuator safety subsystem.
FIG. 3A is a chart of a first group of method steps performed by the transmission control processor.
FIG. 3B is a continuation of FIG. 3A, showing a second group of method steps performed by the transmission control processor.
FIG. 4 is a chart of steps performed by the throttle control processor.
FIG. 5 is a chart of steps for determining what action to take when two feedback signals disagree.
FIG. 6 is a chart of steps for monitoring the correctness of signals from feedback devices.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Automated Manual Transmission. FIG. 1
To provide an example of the invention, the manner in which it is used in a specific AMT is described. The major components and connections of the AMT are shown in FIG. 1. It schematically illustrates an AMT system 10 including an automatic multi-speed compound change gear transmission 12 driven by a throttle-controlled engine 14, such as a diesel engine, through a master clutch 16.
An engine brake, such as an exhaust brake 17 for retarding the rotational speed of engine 14 and/or an input shaft brake 18, which is effective to apply a retarding force to the input shaft upon disengagement of master clutch 16, may be provided, as is known in the prior art. The output of automatic transmission 12 is an output shaft 20 which is adapted for driving connection to an appropriate vehicle component such as the differential of a drive axle, a transfer case or the like.
These power train components are acted upon and monitored by several devices. They include a throttle position monitor assembly 22, which senses the position of the vehicle's throttle and provides signals accordingly; a fuel control device 26 for controlling the amount of fuel to be supplied to engine 14; an engine speed sensor 28, which senses the rotational speed of the engine; a clutch operator and sensor 30, which engages and disengages the clutch 16 and supplies information as to the status of the clutch; an input brake operator 31; a transmission input shaft speed sensor 32; a transmission operator 34, which is effective to shift the transmission 12 into a selected gear ratio and to provide a signal indicative of current transmission status; and a transmission output shaft speed sensor 36.
A vehicle brake monitor 38 senses actuation of the vehicle's brake pedal 40. Alternatively, the engaged gear ratio of transmission 12 may be calculated by comparing the input shaft speed signal 32 with the output shaft speed signal 36.
These devices supply information to and accept commands from a Central Processing Unit (CPU) 42, which controls the AMT. The CPU 42 may include analog and/or digital electronic calculation and logic circuitry, whose specific configuration and structure are not part of the present invention. The CPU 42 also receives information from a shift control assembly 44 by which the vehicle operator may select a reverse (R), neutral (N), or forward drive (D) mode of operation of the vehicle.
An electrical power source (not shown) and a source of pressurized fluid (not shown) provide electrical and pneumatic power to the various sensing, operating and processing units. A fault indicator or alarm device 46 may display the identity of a specific fault or simply signal the existence of an unidentified fault. Drive train components and controls therefor of the type described above are known in the prior art and are explained in greater detail in the above-mentioned U.S. Pat. Nos. 4,361,060; 3,776,048; 4,038,889 and 4,226,295.
Sensors 22, 28, 32, 36, 38 and 44 may be of any known type or construction for generating analog or digital signals indicative of the parameters monitored. Similarly, operators 17, 31, 26, 30 and 34 may be of any known electrical, pneumatic or electropneumatic type for executing operations in response to command signals from the CPU 42.
Fuel control device 26 normally supplies fuel to the engine 14 in accordance with the operator's setting of throttle 24 but may, to synchronize the transmission during an upshift or downshift or to Provide a smooth start, supply a greater or smaller amount of fuel in response to commands from the CPU 42.
The purpose of the CPU 42 is to select, in accordance with a Program (i.e. predetermined logic rules) and current or stored parameters, the optimal gear ratio at which the transmission should be operating and, if necessary, to command a gear change (shift), into the selected optimal gear ratio based upon the current and stored information.
The various functions to be performed by the CPU 42 and a preferred manner of performing them may be seen in more detail in U.S. Pat. No. 4,595,986 and in Society of Automotive Engineers (SAE) Paper No. 831,776 published in November 1983, which are incorporated by reference.
The clutch operator 30 is preferably controlled by the CPU 42 to engage and disengage the master clutch 16 as described in above-mentioned U.S. Pat. No. 4,081,065. The transmission 12 may include synchronizing means, such as an accelerator and/or a brake mechanism as described in U.S. Pat. No. 3,478,851, incorporated by reference. The transmission 12 is Preferably, but not necessarily, of the twin countershaft type as described in U.S. Pat. No. 3,105,395, incorporated by reference.
Throttle Actuator Safety Subsystem. FIG. 2
This section describes components and interconnections involved in the throttle actuator safety subsystem.
The Central Processor Unit (CPU) 42 in this embodiment utilizes two processors, each performing different operations, to accomplish all of the information-processing functions of the AMT system. One of them is a transmission control processor 42A, which performs the system-level processing; the other is a throttle control processor 42B, which performs some of the real-time input and output operations.
Each of the processors 42A, 42B, acting alone is capable of shutting off the fuel flow to the engine 14 if necessary, by acting on a fuel pump 26C. As shown on FIG. 2, there is a connection 23 called "fuel shut-off A" from the transmission control Processor 42A to the fuel pump 26C. There is also a connection 25 called "fuel shut-off B", from the throttle control processor 42B to the fuel pump 26C.
The transmission control processor 42A receives from an accelerator pedal sensor 22P a linear signal (terminal 22A) indicating the position of the accelerator 24A. The accelerator pedal sensor 22P also sends an accelerator idle switch signal (terminal 22B) to the transmission control Processor 42A indicating whether or not the accelerator 24A is in the idle position.
The throttle control processor 42B sends throttle commands on a line 50 to a throttle actuator 26A. The throttle actuator 26A is part of the fuel control device 26 of FIG. 1. The throttle actuator 26A sends linear throttle feedback information (terminal 22C) indicating the throttle actuator's position back to the throttle control processor 42B. The throttle actuator 26A also sends a (throttle) idle switch safety signal (terminal 22D) back to the throttle control processor 42B, indicating whether or not the throttle actuator is in the idle position.
A driver console 45 sends commands (terminal 46A) to the transmission control processor 42A and (terminal 46B) to the throttle control Processor 42B. The driver console 45, which includes the fault indicator 46 of FIG. 1, receives display information (terminal 44A) from the transmission control processor 42A and (terminal 44B) from the throttle control processor 42B.
The throttle control processor 42B also receives engine speed information on a line 52 from the engine speed sensor 28.
Neither the transmission control Processor 42A nor the throttle control processor 42B, when isolated from the other, has complete information on the state of the fuel system. Therefore, it is necessary for normal fuel control that the two processors communicate with each other. An interprocessor communication subsystem, symbolized by line 42C, is provided for this purpose.
Within the interprocessor communication subsystem 42C each Processor 42A, 42B, has several ways to determine whether communications between processors have broken down. Breakdown of communications may be partial or complete. In the event that communications do break down, each processor independently attempts to insure that the throttle actuator 26A is held in a safe state. The method for doing that is one of the subjects of this invention.
During normal operation the transmission control processor 42A informs the throttle control processor 42B via the communications lines 42C how much fuel the transmission control processor 42A is requesting; this is a throttle command. (The throttle control processor 42B then forwards a throttle command on line 50 to the throttle actuator 26A.) The throttle control processor 42B sends information to the transmission control processor 42A (throttle feedback), as to the monitored actual position of the throttle actuator 26A. Both of these values are scaled betweeen 0 and 100%.
Transmission Control Processor. FIGS. 3A and 3B
This section describes method steps Performed by the transmission control processor 42A in Performing those of its functions that relate to the throttle actuator safety subsystem. The accompanying diagram is arbitrarily divided into FIGS. 3A and 3B for convenience of drawing it.
Upon a failure of communications between the two processors 42A, 42B, the transmission control processor 42A still has accurate driver command information (22A, 46A) but only partial information on the state of the throttle actuator 26A. See block 56 of FIG. 3A. The processors 42A, 42B monitor themselves in respect of routine communications capability, in any of many ways that are well-known in computer art. For example, they can detect absence of periodic monitoring signals of Predetermined Proper format when the signals do not occur at the expected times or in expected format. The transmission control processor 42A does not take any safety action when communication with the throttle control processor 42B is impaired as long as the driver's foot continues to depress the accelerator pedal 24A (block 58), as indicated by the accelerator idle switch 22B.
When the driver commands the fuel flow to an idle (22B) by releasing the pedal (line 60), a 300-millisecond delay is provided (block 62). Then the idle safety switch signal (22D) is automatically examined (block 64). If the idle safety switch signal does not indicate an idle condition after 300 milliseconds, the fuel pump 26C is turned off (block 66). On the other hand, if the idle safety switch signal 22D does indicate an idle condition after the 300-millisecond delay (68), no remedial action is taken by the transmission control Processor 42A.
Even when the interprocessor communication subsystem 42C is functioning properly, the transmission control Processor 42A Performs some of the Processing required to insure safe operation of the throttle actuator 26A. An important safety aspect relating to the operation of the throttle actuator 26A is to insure that when the driver removes his foot from the Pedal 24 the throttle actuator 26A in fact returns to idle. The transmission control processor 42A, not the throttle control processor 42B, monitors this aspect, as will now be described.
As shown in the left column of FIG. 3A, when the processors 42A, 42B are communicating properly, the transmission control Processor 42A calculates a throttle command (block 70) on the basis of the pedal input 22A. The throttle command is transmitted (72) to the throttle control processor 42B, and the throttle feedback signal (22C), is passed back (74) from the throttle control processor 42B to the transmission control processor 42A. The throttle command and the throttle feedback are compared in block 76.
When the driver commands (24) a zero-Percent throttle setting (idle), a 300-millisecond delay is initiated (78) to give the throttle actuator 26A enough time to return to the idle position. At the end of that delay:
(a) If both idle switch feedback signals (accelerator idle switch 22B and idle safety switch 22D) indicate an idle condition, it is inferred that the throttle actuator 26C is obeying its commands (block 80 of FIG. 3B); all is well (81) and no corrective action is taken.
(b) If neither of the switches 22B or 22D indicates idle (block 82), a fault is declared and the fuel to the engine is shut off (block 84).
(c) If one of the mechanisms indicates idle and the other does not, the system automatically makes further tests before acting (block 86), as described in a section below headed "When Feedback Signals Are Contradictory".
When the driver commands (24) a non-zero percent throttle setting (77), a procedure (79) is employed called "Verifying Compliance With Throttle Commands", which is described below and in FIG. 6.
Throttle Control Processor, FIG. 4
Some of the critical real-time input/output operations that are performed by the throttle control processor 42B during normal fault-free operation are: (a) collection of wheel-speed sensor data 28; (b) closed-loop control of the throttle actuator 26A; and (c) interfacing (44B, 46B) with the driver's command console 45. See FIG. 2.
As shown in FIG. 4, upon loss of communication 42C between processors, the throttle control processor 42B uses a different approach (block 90) than does the transmission control Processor 42A. The throttle control processor 42B no longer has any information regarding the level of fueling being requested (22A) by the driver. Therefore, for safety, it attempts to drive the throttle actuator 26A back to idle position (block 92), and it turns on a "stop vehicle" indicator lamp on the driver's command console 45.
Thereafter, if the throttle control processor 42B receives verification (block 94) that the throttle actuator 26A has returned to idle position (both the linear feedback signal 22C and the idle safety switch's signal 22D indicate that the throttle actuator is at idle) then no further safety action is taken (95). If verification of a return to idle is not received, the flow of fuel to the fuel pump is shut off (96).
FIG. 4 also shows how the throttle control processor 42B passes throttle signals back and forth between the throttle actuator 26A and the transmission control processor 42A. The throttle control processor 42B reads (block 98) throttle commands that it receives via communication system 42C from the transmission control processor 42A. These commands are forwarded (block 100) to the throttle actuator 26C. Throttle feedback signals 22C from the throttle actuator 26C are received (block 104) by the throttle control processor 42B and forwarded (106) to the transmission control processor 42A.
When Feedback Signals Are Contradictory, FIG. 5
The two feedback devices that ordinarily provide information as to whether the throttle actuator 26A is at idle are a position feedback pot (signal 22C) and the idle safety switch (signal 22D). In an event in which one of those signals indicates that the throttle actuator 26A is at idle and other indicates that it is not, the safety subsystem attempts to determine which of the devices is providing correct information, and acts accordingly.
If the driveline is locked up (block 110), i.e., the clutch 16 is engaged and the transmission 12 is in gear, there is no easy way to ascertain which of the throttle actuator's differing feedback devices is correct. Therefore, the safest response is to stop the fuel to the engine (block 112). On the other hand, if the driveline is not locked up, an opportunity is available to ascertain something about the position of the throttle actuator by examining the engine speed (block 114).
If the engine speed 28 exceeds a first predetermined threshold value far above idle speed, such as 1900 rpm, it is apparent that the throttle actuator 26A is not at idle position. A fault is then declared and the fuel is shut off (block 116).
If the engine speed is below a second predetermined threshold value slightly above nominal idle (block 118), it is relatively safe to assume that the throttle actuator 26A has returned to the idle position. The fuel is left on, because there was only a false alarm. A fault is declared (block 120), identifying which of the feedback devices is providing false information.
The remaining case occurs when the engine speed is between the two threshold values just described. In that instance a further delay of 500 milliseconds is initiated (block 122) to insure that the engine has had sufficient time to respond. If, at the end of the 500-millisecond delay, the engine speed is still not within the idle range, the fuel is shut off (block 124).
Verifying Compliance With Throttle Commands. FIG. 6
It is desirable for the throttle actuator 26A accurately to track the commands (22A, 50) of the driver at settings other than idle; both of the throttle actuator's feedback device signals 22C, 22D are Periodically monitored to detect certain types of malfunctions
When the throttle command 50 exceeds a predetermined relatively low threshold such as 25% of full demand, (see block 130), a series of tests are automatically Performed under control of the throttle control processor 42B. The tests are to ascertain whether the idle safety switch 26D is functioning properly and the throttle actuator 26A is faithfully tracking the command 50.
The two feedback signals 26C and 26D from the throttle actuator 26A are examined by the throttle control Processor 42B (block 132). If neither the idle safety switch 26D is indicating idle (by being closed), nor the feedback pot signal 26C is indicating idle, no corrective action is taken (134). If either signal does indicate idle (136), a 300-millisecond delay is interposed to give those feedback devices enough time to settle into correct Positions (block 138). If, at the end of the delay, either of the two feedback devices is still indicating idle, it is assumed that a malfunction has occurred, and a fault is declared (block 140).
In order to test whether the throttle actuator is correctly tracking the demand, the throttle feedback signal is compared with the throttle command when the accelerator pedal is not moving. If the throttle feedback signal exceeds the command by more than 10%, a 300-millisecond delay is initiated to give the throttle feedback signal time to come within that 10% range. If the throttle actuator does not come within 10% of command during that delay time a fault is declared. A simple figure illustrating the steps of this feature could be similar to the figures described above.
Scope of Invention
Although a fully automatic AMT system 10 is illustrated, the present invention is also applicable to semi-automatic AMT systems where the system automatically executes driver-selected gear changes.
Although the AMT system 10 has been described as utilizing a microprocessor-based control 42 and the methods and operations are carried out as software algorithms, it is clear that the operations can also be carried out in electronic or fluidic logic circuits comprising discrete hardware components.
Although the present invention has been set forth in terms of a particular preferred embodiment, various modifications including but not limited to those alluded to above are possible within the scope of the invention as claimed.
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A safety method is provided for use with control systems for vehicles such as trucks, and in particular for electromechanical controls (10) that assist the driver in shifting the gears (12), operating the clutch (16), and in actuating the throttle (22, 24, 26) by remote control. The method, which is for use in a vehicle's throttle-actuator subsystem (26A), utilizes a transmission control processor (42A) and a throttle control processor (42B). The method ascertains whether, when the driver of the vehicle removes his foot from the accelerator pedal (24A), control of the fuel pump (26C) returns to the idle governor as it should. The flow of fuel is stopped if it does not return properly. Also, a method is provided that monitors the throttle actuator (26A) to insure that it accurately follows throttle commands such as the position of the accelerator pedal (24A).
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BACKGROUND OF THE INVENTION
This invention relates to a transaction processor in which cash such as notes, checks and the like can be deposited by inserting them into an inserting opening, and cash can also be deposited in a state wherein cash is put into an envelope.
As is well known, automatic deposit apparatus installed in financial instructions such as banks include various devices, such as for example, a note exclusive-use machine, a check exclusive-use machine or a machine which can handle notes and checks. In any of these machines, cash such as notes, checks or the like inserted is checked for genuineness. A standard of judgement for genuineness is whether or not, in case of a note, a note read-in apparatus can read it, or whether or not, in case of checks, a character read-in apparatus can read it. In the case of notes, when printing on notes is obscure or notes are bent, such as notes are sometimes judged to be defective or bad. On the other hand, in case of checks, if it is hand-written, mis-judgement sometimes occurs.
A conventional transaction processor is designed so that if notes or checks to be deposited by a client, are judged as defective such a deposit is collectively returned to the client so as not to accept the deposit. If rejection of acceptance is caused by a bend of the notes or checks, such a bend is corrected properly and notes or checks are re-inserted, then the expected deposit can be made and therefore, a problem hardly occurs. However, if rejection of acceptance is caused by the reading ability of the machine such as obscure printing, a client cannot make his expected deposit, thus posing a problem. In such a case, the client has to carry cash to a bank-counter to request a staff member to execute a deposit procedure.
This significantly impairs introduction of the machine and imposes an additional burden on the staff.
BRIEF SUMMARY OF THE INVENTION
It is an object of this invention to provide a transaction processor in which cash put into an envelope can be deposited in addition to the deposit of cash such as notes, checks or the like.
In accordance with the present invention, among cash to be deposited by a client, those which are acceptable are processed for deposit immediately, and those which are unacceptable are returned. At that time, the client can put the returned cash into an envelope for deposit. That is, the client can deposit all cash, which are expected to be deposited at the outset, as expected, thereby greatly enchancing services for clients. Since, at this time, processing made by a staff is directed to only cash which cannot be processed by the machine, a burden on the staff is relieved.
Other and further objects of this invention will become obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an external view showing a transaction processor as one embodiment of the present invention.
FIG. 2 is a schematic block diagram showing a fundamental electric structure of apparatus in said embodiment.
FIGS. 3(A) and 3(B) are flow charts showing control operation of said apparatus, principally showing parts related to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, an operating section which carries out transactions is arranged in a front surface of a transaction processor 1. A display 2 is arranged approximately in a central portion of a horizontal panel of said operation section, which display 2 is provided to display, to an operator, a message, amount and the like required for a transaction. To the left of the display 2 are arranged a note inserting opening 3 through which notes are inserted, a note returning opening 4 thorugh which notes, which cannot be read in the deposit mode, are returned, and a check inserting opening 5 through which checks are inserted. To the right of the display 2 are arranged a function key 6 for effecting setting of modes or the like and ten key keyboard 7 for entering numeric information. In a vertical panel of the operating section are arranged a bank-book inserting opening 8, a card inserting opening 9, an envelope inserting opening 10 through which an envelope having notes or checks put therein is inserted in an envelope deposit mode, and a chit issuing opening 11 for issuing various chits such as a deposit chit, a chit for a detailed statement of deposit amount or a chit for a receipt of envelope, etc. requested in an envelope deposit mode.
FIG. 2 shows a fundamental structure of the aforesaid transaction apparatus.
A note input and output device 20 includes said note inserting opening 3 and note returning opening 4, and receive notes inserted into the note inserting opening 3 one by one to judge the genuineness, kind and number of notes, whereby those which have been accurately read as true notes are stacked on a stacker not shown, and those which have not been accurately read, among forged notes and true notes, are returned to the note returning opening 4. A check input device 21 includes the check inserting opening 5 to read various kinds of checks inserted, hand-written amount and the like, whereby those which have been accurately read in all information required for transaction as true checks are stacked on a stacker not shown, and those which have not been accurately read in forged checks and information required for transaction of hand-written amount and the like are returned to the inserting opening 5. Data read by the note input and output device 20 and check input device 21 are entered into CPU 30. An envelope input device 22 includes the envelope inserting opening 10, and when an envelope having notes or checks put therein is inserted, said envelope is transferred to an envelope stacker not shown. A card input device 23 includes the card inserting opening 9 to read information such as account number, bank number and the like magnetically recorded on the card, which information is put into CPU 30. A bank-book input device 24 includes the bank-book inserting opening 8 for reading information recorded on a magnetic stripe of the inserted bank-book by means of a magnetic head and optically reading a page mark and a print mark, which information is put into CPU 30. The page mark and print mark are checked to determine a next printing position. This is well known, details of which therefore will not be described. A chit issuing device 25 includes the chit issuing opening 11 to print predetermined information in connection with a transaction on a sheet of recording paper on the basis of command of CPU 30 and issue the printed recording paper as a transaction chit. A display device 26 includes a display portion 2 for displaying a message and amount required for operation of a transaction for a client. The function key 6 includes a key for setting transaction modes to a deposit mode which uses a card or a bank-book, an envelope deposit mode which uses an envelope or other modes, a key to designate if deposit is made by notes or checks, and a confirmation key for confirming a deposited amount, in which outputs of keys operated are effectively put in when the CPU 30 is in a key input waiting state. In this embodiment, the deposit mode is classified into a card deposit mode which uses a card and a bank-book deposit mode which uses a bank-book. A ten key keyboard 7 is provided to input predetermined numeric information required for a transaction in response to the message displayed on the aforesaid display 2, and outputs of operated keys are effectively put in when the CPU 30 is in a key input waiting state.
The CPU 30 transfers data between the aforesaid I/O devices to prepare transaction data to be transmitted to the center for every transaction. Said transaction data are put on a transmission line 32 by MODEM 31 and is sent to the center through MODEM 33 arranged in the center section. The CPU 30 includes a ROM which stores the control procedure for controlling the aforesaid I/O devices and the control procedure for transmitting the transaction data to the center, and a RAM to which work areas, flags and the like required for processing data are assigned.
Next, among control operations of the CPU 30, operation of each of the deposit mode and envelope deposit mode will be described with reference to a flow chart shown in FIG. 3.
When a power source is closed to initialize the CPU 30, the CPU 30 displays "Operate the function key 6" on the display 2 (Step 300) to form a key input waiting state of the function key 6. When the key is operated in the function key input waiting state, the transaction mode is set in response to the thus operated key. As a result, when the transaction mode is in the card deposit mode, the step proceeds to Step 301; when in the bank-book deposit mode, the step proceeds to Step 302; and when in the envelope deposit mode, the step proceeds to Step 303.
First, the case where the transaction mode is set to the deposit mode will be described.
In Step 304, the CPU 30 displays "Insert a card" on the display 2. In this stage, only the card input device among the various input devices is effectively actuated but other input devices are not actuated. Thus, insertion of bank-book or the like is not possible. When the card is inserted, the card input device 23 reads information magnetically recorded on the inserted card to release the read data to the CPU 30. The CPU 30 prepares a column of data required to initiate a transaction such as account number, bank number, etc. to be sent to the center on the basis of said read data to store them in a predetermined storage region within the RAM and to display a request for designation of an object for deposit, that is, "Designate if deposit is notes or checks" (Step 305). If the client operates the note key among the function keys, the step proceeds to Step 306 and 307; if operates the check key, the step proceeds to Step 308 and 309; and if operates both the note key and check key, the step proceeds to Step 310. That is, the CPU 30 displays "Insert notes" on the display 2 if the step proceeds to Step 307; displays "Insert checks" if the step proceeds to Step 309; and displays "First, insert notes" if the step proceeds to Step 310.
When notes or checks are inserted in a manner as described above, processing necessary for a transaction will begin.
In case of the card deposit mode, when only the note key is operated, only the note inserted is read in Step 311. This reading of the note is carried out by the note input and output device 20. The note input and output device 20 further judges the genuineness and kind of notes from the thus read data or data set and stored in RAM and ROM (Step 312). If the true notes and kind thereof are accurately read, said notes are transferred to the stacker not shown, and values in the amount storage region within the RAM are counted and stored as a deposit amount by adding only an amount deposited (Step 313). It is noted that the amount storage region which stores values counted in Step 313 is reset to zero upon completion of one transaction. Subsequently, inspection is made if processing of reading notes one by one has completed on all notes inserted into the note inserting opening 3 (Step 314). This inspection is carried out by detection that a note detection signal from a photoelectric switch (not shown) provided on a transfer passage which transfers notes, which are inserted into the note inserting opening 3, one by one has been stopped for a given period of time, or by detection that a photoelectric switch, not shown, which detects notes present in the note inserting opening 3 has failed to detect notes. In the case that all the inserted notes are true and can be read at once, processing of the aforesaid Step 311 to 314 are repeated through the number of notes inserted. The deposited amount is displayed (Step 315) and the step proceeds to Step 316. On the other hand, when forged notes or notes which are poor in printing accuracy and difficult to read are present, such notes are again read in Steps 312 and 318. The result obtained therefrom is again judged in Step 312. This re-reading is executed through a number of times, which are predetermined n times (for example, three times). If the notes can be accurately judged as the true notes as well as the kind thereof during that time, said notes are processed for deposit in Step 313. The number of judgements is counted by adding, by one, counted values in the storage region for storing the number of times within the RAM every time the step proceeds from Step 312 to Step 318. And, in Step 319, inspection is made if the counted value in the storage area for storing the number of times is equal to n times (for example, 3 ). When notes are judged to be forged notes or to be impossible to read by re-reading them n times, said notes are returned to the note returning opening 4 (Step 320), and when the client has picked up the thus returned notes (Step 321), the step proceeds to Step 314. When notes are judged to be true in the judgement of step 312 or when removal of notes is detected by means of a photoelectric device not shown in step 321, the stored value in the storage region for storing the number of times is reset to zero. In this manner, all the inserted notes are judged in Step 312 to accept only notes which can be transacted for counting processing (Step 313). When the client has confirmed the amount displayed on the display 2 (which is the amount accepted as transactable notes) after the aformentioned processing has been finished and the confirmation key within the function key 6 is operated (Step 316), data are transferred to and from the center (Step 322). Then, transacted data are printed on a sheet of recording paper on the basis of data received from the center (Step 323) and the chit and card are released (Step 324). When the client removes the chit out of the chit issuing opening 11 and removes the card out of the card inserting opening 9, the CPU 30 judges the presence or absence of the returned notes (Step 325). As a result, if the returned notes are presented, "Do you want to deposit returned notes in envelope?" is displayed (Step 306), and if returned notes are not present, the step terminates. And, when the envelope deposit mode setting key within the function key 6 is operated, the step proceeds to Step 328, and if the envelope deposit mode setting key is not operated within a given period of time, the step terminates.
If, in the card deposit mode, only the check key is operated (Step 308), and a check is inserted into the check inserting opening 5 in Step 309, reading of the check is first executed in Step 329 in a manner similar to the case of notes. This reading is carried out by the check input device 21. The check input device 21 judges, in its reading, if the check is true and if the amount described in an amount column can be read accurately (Step 330). As the result, if the check is true and the amount can be read accurately, the step proceeds to Step 315 to display the amount. If the check is found to be a forged check or the described amount cannot be read accurately, re-reading is tried through a maximum of n times exactly in the same manner as in the case of notes (Steps 331 and 332). If reading was made during that period, the read amount is added to the stored value in the amount storage region within the RAM, and the step proceeds to Step 315 and otherwise the check is returned in Step 333. If the check is removed in Step 334, processing of each of the afore-mentioned Steps 316 to 327 is executed. It is noted that the stored value in the amount storage region is reset every time the transaction terminates. In Step 326, "Do you want to deposit a returned check in envelope?"is displayed on the display 2.
Next, where the bank-book deposit mode is set (Step 302), the display 2 displays "Insert a bank-book" (Step 335), and the step proceeds to Step 305. Thereafter, the above described Steps are executed. It is noted in Step 323 that transacted data are printed on the bank-book but a chit is issued if necessary. In Step 314, the bank-book and necessary chits are released.
On the other hand, in the card deposit mode or bank-deposit mode, both the note key and check key are operated, that is, when the step proceeds to Step 306→308→310, processing for notes is first carried out in Steps 336 to 344 in a manner similar to the above described manner. Next, the CPU 30 displays "Insert a check" on the display 2 (Step 345), and when the client inserts a check into the check inserting opening 5, processing for the check is carried out in Steps 346 to 352 similiarly to the former.
Next, the operation in which the envelope deposit mode is set will be described.
When the envelope deposit mode setting key is operated in Step 327 or in the first Step 300, the step proceeds to Step 328 and "Insert a card" is displayed on the display 2 to wait for insertion of the card by the client. When the client inserts the card, "Request to deposit an amount to be put into an envelope" is displayed on the display 2 (Step 353). Thereby the client inputs a total amount of notes and/or checks to be put into envelope from the ten key 7 to effect request to deposit the amount to be put into an envelope. When this request is made, a detailed chit, on which data such as an amount based on the request and the account number read from the card are recorded, is issued from the chit issuing opening (Step 354). Subsequently, in Step 355, "Insert an envelope into an envelope inserting opening" is display 2. When the envelope is inserted, a receipt chit indicative of the fact that the envelope has been received, is issued from the chit issuing opening 11 (Step 356). At the same time, the card is returned (Step 357). The step terminates when the card and receipt chit are removed.
While in the above-described embodiment, it is possible to deposit both notes and checks as well as to use an envelope deposit therefor, it should be noted that in case where notes are high in precision and misreading hardly occurs, the envelope deposit for only checks can be made.
In addition, it is needless to say that the present invention may be applied even to apparatus which can handle only the note deposit, apparatus which can handle only the check deposit, apparatus which can use only card or apparatus which can use only the bank-book.
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A deposit mode for inserting cash into an inserting opening for cash deposit and an envelope deposit mode for putting cash into an envelope and inserting the envelope into an opening for deposit are selectively set by a transaction mode setting unit. In the cash deposit mode, acceptance of cash inserted into the inserting opening for deposit is judged by a judgement unit. A deposit mode processing unit is provided to effect deposit processing for acceptable cash and to effect return processing for unacceptable cash which is not capable of being transacted, in accordance with the result of the judgement. An inquiry is made by a display unit to a depositor concerning whether or not returned money will be deposited in an envelope. In the envelope deposit mode, a request instructing unit instructs a client to input a value for an amount of cash to be placed into an envelope. Deposit processing based on the requested amount and processing of accepting the inserted envelope are effected by an envelope deposit mode processing unit.
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FIELD OF THE INVENTION
The present invention relates to the field of cameras and, more particularly, to a parallax compensation system for a camera.
BACKGROUND OF THE INVENTION
Cameras having non-through the lens viewfinders, that is, viewfinders with an optical axis distanced from the image capture optical axis, exhibit a problem with parallax error at close shooting distances. At normal shooting distances (1.5 m to infinity) the parallax error is negligible. However, at very close shooting distances (i.e. 0.25 m), the parallax error causes unacceptable aiming mistakes. There are several existing methods to address this problem: 1) ignore it for very low-end cameras and simply accept aiming errors; 2) add so-called parallax markings in the bright frame mask, which require the user to remember to use those markings to recompose the subject if it is at close distance; 3) use a bright frame viewfinder with parallax markings and control the visibility of those markings automatically with moving masks or with liquid crystal panels; 4) employ an elaborate mechanism to couple the viewfinder mask or bright frame to the focusing movement of the lens, which mechanism typically comprises cams and levers and even motors in some high-end cameras.
A number of patents have tried different means for addressing the parallax error in cameras at close shooting distances. U.S. Pat. No. 6,243,539 to Chen provides a parallax compensation apparatus for a camera which comprises a viewfinder pivotally connected to a camera for locating objects to be taken. A follower link connected to the camera and having one end pivotally connected to the viewfinder causes the viewfinder to pivot, moving the adjusting device such that the optical axis of the viewfinder meets the optical axis of the lens in the subject to be taken.
U.S. Pat. No. 4,924,247 to Suzuki et al., relates to an apparatus and method for correcting and adjusting parallax in an electronic camera. Suzuki provides a parallax correcting apparatus which comprises an imaging device driving mechanism for supporting and moving an imaging device away from and towards the optical axis of the finder optical system.
Although somewhat effective for their intended purpose, the prior art devices are complicated and expensive. What is needed is a mechanically simple, inexpensive system for correcting parallax in a camera having an independent viewfinder. This object, as well as others, is satisfied by the present invention.
SUMMARY OF THE INVENTION
A parallax compensation system and method is provided for a camera including a non-through the lens viewfinder. The taking lens of a camera is mounted eccentrically in a cylindrical lens barrel. The lens barrel is rotated to shift the taking lens towards the viewfinder for close focus shots. Additionally, in one particular embodiment, the viewfinder axis is tilted towards the rotated taking lens axis to help eliminate parallax in close focus pictures.
These and other objects and advantages of the present invention will become more readily apparent in the description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings an exemplary embodiment that is presently preferred it being understood, however, that the invention is not limited to the specific methods and instrumentality's disclosed. Additionally, like reference numerals represent like items throughout the drawings. In the drawings:
FIG. 1A is a perspective view from the front, right side of an exemplary camera useful with the present invention.
FIG. 1B is a perspective view from the rear, right side of the camera of FIG. 1 A.
FIG. 2A demonstrates the parallax encountered at close range with a standard camera having an independent viewfinder.
FIGS. 2B-2D demonstrates the elimination of parallax at close range in a camera made in accordance with various embodiments of the present invention.
FIG. 3A is a front plan view of an eccentric lens barrel in accordance with one embodiment of the present invention.
FIG. 3B is a side perspective view of the eccentric lens barrel of FIG. 3 A.
FIG. 4A is a front partial cut-away view of a camera made in accordance with one embodiment of the present invention.
FIG. 4B is an enlarged view of the cut away portion of FIG. 4 A.
FIG. 4C is a side perspective, partial exploded view of the camera of FIG. 4A
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before explaining the disclosed embodiments of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
The present invention relate to a camera with a first fixed-focus setting for normal shooting distances and a separate fixed-focus setting for close-up pictures. The fixed-focus setting for close distances is used to shift the center of the lens relative to the center of the image frame so as to help compensate for the parallax error of the viewfinder.
Referring now to FIGS. 1A and 1B, the camera 10 includes an outer housing 11 having a front portion 12 a and a back portion 12 b. The front portion 12 a and the back portion 12 b are made as two separate pieces to facilitate manufacturing of the housing 11 . It should be appreciated, however, that the housing may, alternatively, be comprised of any number of pieces. Additionally, the outer surfaces of the front 12 a and back 12 b portions may be contoured, if desired, to improve gripping capabilities and provide a more ergonomic and aesthetically pleasing design. In the preferred embodiment, the housing 11 is constructed of a lightweight, yet rugged plastic material, but may, alternatively, be constructed of an alloy material, a metallic material or any other suitable material.
Front portion 12 a of housing 11 is adapted for connective engagement with the corresponding back portion 12 b using conventional fastening means. The two halves form a substantially light tight connection when assembled together. In the present embodiment, the front and rear portions 12 a and 12 b are secured together using screws 14 .
The front and back portions 12 a, 12 b include a plurality of openings integrally formed therein. The openings are structured and disposed to accept the taking lens (opening 16 )defining an image capture optical axis and a viewfinder assembly (openings 18 a and 18 b ) defining an image framing optical path, the viewfinder assembly disposed apart from the taking lens. Other openings may also be included to accommodate other features, such as a battery door, function select controls, a flash and/or an external connector.
A trigger button 13 is accessible through an opening disposed on the top face 12 c of the housing 11 .
An external interface cavity 30 is also integrally formed in the camera housing 11 and is accessible by moving the interface door 31 . External interfaces are disposed within the external interface cavity 30 for interconnection with an external device, such as a computer, printer, television or video monitor, imaging device, etc.
A status indicator opening 40 is provided through the rear housing 12 b. A status LCD 41 is mounted on the rear housing 12 b. Additional openings for a number of user select buttons 42 are additionally provided through the rear housing, and are disposed in close proximity to the status indicator. The number and orientation of the user select buttons 42 may vary to accommodate the particular camera 10 layout. Similarly, the functions provided may vary. Typical function selects include, on/off, timer on/off, etc. Additionally, the status LCD 41 may provide a variety of desired information including timer indication, battery status, number of remaining pictures, mode indicator, etc.
The present exemplary camera additionally includes a mirror slide switch 60 slideably engaged with the top face 12 c of the housing 11 . Further, as will be described more filly herein, camera 10 includes a wiper switch 50 that slides in a groove formed in the front housing 12 a and which switches the camera mode between normal and macro.
Referring now to FIG. 2A, there is shown a schematic illustration showing parallax error in a close focus picture taken with a conventional camera. A viewfinder optical axis 100 is defined through the center of the viewfinder of the camera. An image capture optical axis 110 is defined through the center of the camera image sensor. The viewfinder optical axis 100 and the image capture optical axis 110 are fixed parallel to each other. Objective taking lens 112 is centered on the sensor axis 110 . Parallax is defined as the difference between the area taken in by a camera lens and the area seen in the viewfinder. The closer the subject is to the camera, the greater the parallax. As such, at close range, the image recorded by the sensor is shifted as compared to the image framed in the viewfinder.
Referring now to FIG. 2B, there is shown a schematic illustration using a camera in accordance with one embodiment of the present invention. To compensate for parallax in the present embodiment, objective taking lens 112 is shifted towards the viewfinder axis. Although the image sensor is not shifted, shifting the lens alters the focus of the sensor. Once shifted, the parallax between the viewfinder and the taking lens is eliminated at a relatively close focal length, where the newly defined optical center axis 114 converges with the viewfinder axis 100 . The amount of lens shift needed can be described by the following equation:
Lens Shift=Parallax Distance×Focal Length/Subject Distance (1)
where, parallax distance is the distance between the taking lens center and the viewfinder center.
In one particular implementation shown in FIG. 2B, the taking lens 112 was shifted 0.39 millimeters causing the lens axis 114 to converge with the viewfinder axis 100 at 380 mm, thus eliminating parallax at this distance. However, it has been found that shifting the lens center 112 too far from the sensor center can cause degradation in the corners of the picture.
Referring now to FIGS. 2C and 2D, there is shown another embodiment of the camera of the present invention. In the embodiment of FIGS. 2C and 2D, to prevent the lens from shifting too far from the center of the sensor, the taking lens 112 is shifted a small distance away from the viewfinder axis 100 for far focus shots, but is shifted towards the viewfinder axis 100 for close focus shots. Additionally in this embodiment, the viewfinder is tilted towards the sensor axis 110 . To reduce cost, the viewfinder of the present embodiment is permanently angled towards the taking lens, defining an adjusted viewfinder axis 116 .
For far focus shots, the taking lens 112 is shifted away from the adjusted viewfinder axis 116 , defining an adjusted far focus lens axis 118 . For close focus shots, the taking lens 112 is shifted towards the adjusted viewfinder axis 116 , defining the adjusted viewfinder close focus axis 118 ′.
In one particular implementation having the viewfinder permanently tilted, as shown in FIG. 2C, shifting the taking lens 112 away from the viewfinder axis 100 by 0.15 millimeters from the original lens axis 110 resulted in a far focus convergence of the adjusted viewfinder axis 116 with the adjusted far focus lens axis 118 at 1700 millimeters. In the same embodiment, as shown in FIG. 2D, shifting the taking lens 112 towards the viewfinder axis 100 by 0.15 millimeters from the original lens axis 110 resulted in a close focus convergence of the adjusted viewfinder axis 116 with the adjusted close focus lens axis 118 ′ at 380 millimeters, thus eliminating parallax at that distance.
Referring now to FIGS. 3A and 3B, there is shown one embodiment of an eccentric taking lens barrel 130 which may be used to implement the lens shift described in connection with the FIGS. 2B-2D. An eccentric taking lens barrel 130 is shown such that the barrel includes a bore 131 . Although the lens barrel 130 is cylindrical in shape in this particular embodiment, the bore 131 is located off center in the lens barrel 130 such that the length R 1 is significantly greater than length R 2 , where R 1 is measured from the center of the bore to the furthest outer edge of the lens barrel 3 O and R 2 is measured from the center of the bore to the closest outer edge of the lens barrel 130 . The lens assembly 140 , including the taking lens group 142 , is mounted in the bore 131 . The taking lens barrel 130 additionally includes cam arms 132 , 134 and 136 , which engage cam surfaces on the body of the camera to limit the range of motion, when the lens barrel is rotated. Cam arm 136 further includes the wiper post 138 . Wiper post 138 interfaces with a wiper or switch outside the camera housing to permit the user to manually rotate the lens assembly 140 .
Referring now to FIGS. 4A, 4 B and 4 C, there is shown a camera 150 that incorporates one embodiment of the present invention. Camera 150 includes a viewfinder assembly 160 having lenses 162 and 164 and a taking lens assembly 140 seated in an eccentric taking lens barrel 130 . In the present embodiment, the viewfinder assembly of camera 150 is permanently tilted towards the taking lens 142 such that the vector 165 (FIG. 4A) defines the tilted viewfinder axis. Additionally, the eccentric lens barrel 130 is free to rotate only a prescribed amount in the camera body. Rotating the lens barrel 130 clockwise (as shown in shadow by the displacement 136 ′, 140 ′ of arm 136 and taking lens assembly 140 , respectively) brings the taking lens 142 ( 142 ′) closer to the viewfinder. Line D 1 is the distance from the center of the viewfinder to the center of the unshifted taking lens 142 . Line D 2 is the distance from the center of the viewfinder to the center of the shifted taking lens 142 ′. As can be seen, when the eccentric lens barrel 130 is shifted the taking lens 142 is shifted ( 142 ′) closer to the viewfinder. As described in connection with FIGS. 2B-2D, this reduces the parallax of the camera for close focus pictures, while having a negligible effect on far focus pictures. A sensor 170 seated in the body of camera 150 behind the taking lens 130 captures the image when the trigger ( 13 of FIGS. 1A and 1B) is depressed. An internal coupling ring 185 couples the eccentric lens barrel 130 to the front cover wiper 180 on the outside of the housing.
Note that the disclosed method of shifting the taking lens can be applied to all kinds of image capture devices including cameras wherein the image recording media is photographic film, or wherein the image recording media includes a CMOS or CCD sensor as described herein. The present invention is particularly suitable for digital cameras due to the small size of the image frame on the sensor and therefore the small amount the lens needs to shift sideways for parallax compensation. It is understood that the lens shift must be limited to the maximum extent of the image circle (maximum coverage of the lens) to avoid poor image quality in the corners.
While the invention has been described with reference to certain embodiments, 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 can 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.
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A parallax compensation system and method is provided for a camera including an independent viewfinder. For close focus pictures, the camera's taking lens is shifted towards the viewfinder. In one embodiment, for far focus pictures the camera's taking lens is moved away from the viewfinder and is not centered on the image recording medium axis. The lens shifting is accomplished by mounting the taking lens eccentrically in a lens barrel. Rotation of the lens barrel shifts the taking lens towards the independent viewfinder for close focus shots. In one embodiment, the viewfinder axis is tilted towards the taking lens to help eliminate parallax in close focus pictures.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a color cathode-ray tube (CRT) of a dot-in-line type. More specifically, the present invention pertains to a color CRT in which electron guns are in an in-line array and apertures of a shadow mask are circular and particularly to an array of the apertures.
2. Description of the Prior Art
A color CRT of a dot-in-line type includes a set of three electron guns in an in-line array for emitting three electron beams for three different colors. Ahead of the electron guns, a shadow mask with a curved surface is disposed in a direction intersecting with the electron beams and, further ahead of the shadow mask, a fluorescent screen having a curved surface similar to the curved surface of the shadow mask is provided in parallel with the shadow mask. The shadow mask has a large number of small circular apertures, in a dotted manner, instead of elliptical or slitted apertures.
One of the problems in the landing characteristics of the electron beams in such a conventional dot-in-line type color CRT is, as described in the official gazettes of Japanese Patent Publication Nos. 21214/1975 and 19909/1965, that the pattern of arrival points of the electron beams on the fluorescent screen does not become one having a close packed structure.
FIG. 1 is a schematic illustration for explaining a relation between a set of electron beams in an in-line array and an array of apertures of a shadow mask. In FIG. 1, the in-line array of electron beams is provided parallel to the horizontal direction of a fluorescent screen 1, electron beams for blue, green and red colors being shown on an enlarged scale as BB, BG and BR, respectively. As shown in FIG. 1, it is assumed that an X axis parallel to the in-line array passes through the center of the fluorescent screen and a Y axis vertical to the X axis also passes through the center. In an inserted circle A in FIG. 1, a part of an array of apertures of a shadow mask 2 set near the fluorescent screen 1 is shown on an enlarged scale, with a broken line B as one of lines connecting the nearest apertures out of the apertures 2a being parallel with the Y axis. The fluorescent screen 1 is generally formed on the inner surface of a glass panel. Since this glass panel finally constitutes a vacuum vessel for serving as a CRT, the panel is formed to have a spherical surface to prevent an explosive break thereof and the shadow mask 2 is also formed to have a spherical surface corresponding to the fluorescent screen 1.
FIG. 2 is a schematic illustration showing an inclination of a trio of electron beams in each corner portion of the fluorescent screen 1. In FIG. 2, the characteristics of a pattern of arrival points of a trio of electron beams BB, BG and BR in the respective portions of the fluorescent screen 1 after passing through an aperture 2a of the shadow mask 2 are illustrated in an exaggerated manner on an enlarged scale. More specifically, since the fluorescent screen 1 has a spherical surface, the arrival points of the trio of beams BB, BF and BR, for example in a corner portion C of the first quadrant, are arrayed downward to the right. FIG. 3 is a detailed illustration, on an even more enlarged scale, showing the arrival points of the electron beams in the corner portion C shown in FIG. 2. In FIG. 3, the arrival points of a trio of electron beams through an aperture 2-1 (not shown) of the shadow mask 2 are shown as B 1 , G 1 and R 1 , and similarly the arrival points of trios of electron beams through an adjacent aperture 2-2 (not shown) on the right of the aperture 2-1 and an adjacent aperture 2-3 (not shown) on the downward right of the aperture 2-2 are shown as B 2 , G 2 and R 2 , and B 3 , G 3 and R 3 , respectively. As seen in FIG. 3, there is a problem that a broken line D connecting the points B 1 , G 1 and R 1 and a broken line E connecting the points B 2 , G 2 and R 2 are not continuous between the points R 1 and B 2 , causing a step therebetween. In addition, since a broken line F connecting a trio of arrival points B 3 , G 3 and R 3 of electron beams through the aperture 2-3 is also inclined as shown in FIG. 3, a distance between the points B 3 and R 1 becomes extraordinarily short, which constitutes one of the particularly disadvantageous aspects of the landing characteristics in the dot-in-line type of color CRTs.
FIG. 4 is a schematic illustration showing an ideal case corresponding to FIG. 3. The arrival points of electron beams in FIG. 4 form a close packed structure, in which regular triangles respectively formed by the nearest three arrival points are laid most densely. In such an ideal case, the fluorescent screen is utilized most effectively. In other words, the space utilization factor of the screen is at its optimum.
FIG. 5 is a schematic illustration representing a distribution of apertures in a shadow mask utilized in the above described Japanese Patent Publication No. 19909/1975 with a view to avoiding such distortion as shown in FIG. 3. Referring to FIG. 5, the X axis is parallel to the in-line direction, passing through the center of the shadow mask and the Y axis passing through the center is vertical to the X axis. As seen in FIG. 5, rows of apertures of the shadow mask in the direction of the X axis are curved in the shape of a barrel, while columns of apertures in the direction of the Y axis are curved in the shape of a pincushion. Such array of apertures makes it possible to correct such distortion as shown in FIG. 3 to take a closer approach to the ideal state as shown in FIG. 4. However, the rows and columns of such array of apertures are not parallel to the X axis or to the Y axis and, as a result, the manufacturing of such a mask is complicated and expensive.
On the other hand, some other arrays of apertures are proposed for the purpose of solving the above described problem. However, they are improved arrays only in one dimension (only in one direction) and none of them can solve the above described problem satisfactorily.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a color CRT comprising a shadow mask, in which an array of apertures of the shadow mask has a two-dimensionally improved pattern with a better effect than in case of an one-dimensionally improved pattern and such minimum distance as that between R 1 and B 3 in FIG. 3 is made longer to allow a larger landing tolerance of the electron beams.
It is another object of the invention to provide a color CRT comprising a shadow mask with a two-dimensionally improved array of apertures, in which the array of apertures can be manufactured more easily and at lower cost than conventional two dimensionally improved arrays.
A color CRT in accordance with an embodiment of the present invention comprises a set of three electron guns in an in-line array, a shadow mask with a curved surface having a plurality of circular small apertures and a fluorescent screen disposed in parallel with the shadow mask and including fluorescent dots arrayed in association with three electron beams passing through the apertures, and the shadow mask includes an X axis and a Y axis passing through the center in the flat state before the mask is pressed to have a curved surface, the X axis being horizontal in parallel with the direction of the above stated in-line array, the Y axis being vertical to the X axis, rows of the apertures in the direction of the X axis being curved more prominently in the shape of a barrel according to increase of the distance from the X axis and columns of said apertures in the direction of the Y axis being all straight lines parallel to the Y axis.
These objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration showing a relation between an in-line array of electron beams and an array of apertures of a shadow mask in a conventional color CRT;
FIG. 2 is a schematic illustration for explaining inclinations of trios of electron beams in the vicinity of corner portions on a fluorescent screen;
FIG. 3 is a more detailed illustration showing a corner portion C in FIG. 2;
FIG. 4 is a schematic illustration showing a pattern of arrival points of electron beams in the ideal case;
FIG. 5 is a schematic illustration for explaining a curved array of rows and columns of apertures of a conventional shadow mask proposed for the purpose of avoiding such distortion as shown in FIG. 3;
FIG. 6 is a schematic illustration for explaining a distribution of apertures in a shadow mask in a color CRT in accordance with an embodiment of the present invention;
FIG. 7A is a diagram showing a gradual change in the pitches of apertures of a shadow mask in the direction of the Y axis in accordance with the present invention;
FIG. 7B is a diagram showing a gradual change in pitches of apertures of a shadow mask in the direction of the X axis in accordance with the present invention;
FIG. 8 is a schematic illustration for explaining pitches in an array of apertures in the center and in a corner portion of a shadow mask;
FIG. 9A is a diagram showing a gradual change in pitches in an array of apertures of a shadow mask in accordance with an embodiment of the present invention;
FIG. 9B is a diagram showing a gradual change in pitches of apertures in a shadow mask in accordance with another embodiment of the present invention; and
FIG. 10 is a diagram showing a relation between percentages of correction of pitches of adjacent apertures in a shadow mask and percentages of correction of the distance between the nearest arrival points of electron beams.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 6, the center O of a shadow mask corresponds to the center of the fluorescent screen shown in FIG. 2 and the horizontal X axispassing through the center O is parallel with the in-line direction, the Y axis through the center O being vertical to the X axis. In an array of apertures of the shadow mask in FIG. 6, rows of apertures arrayed in the Xaxis direction are curved more prominently in the shape of a barrel as the distance from the X axis becomes larger, while columns of apertures in theY axis direction are all arrayed in straight lines parallel to the Y axis irrespectively of the distance from the Y axis.
On the Y axis, apertures 2a in an even-numbered row M 2n (n being an integer) are provided at a pitch a 0 and on the X axis, apertures 2a in an even-numbered column N 2n are provided at a pitch b 2n . In the column N 2n , apertures 2a are provided at a pitch a N in the Yaxis direction.
An aperture in an odd-numbered column N 2n+1 is at a position surrounded by the M 2n th and the Mh 2n+2 th apertures in the Y axis direction belonging in the even-numbered columns N 2n and N 2n+2 adjacent to both sides of column N 2n+1 , the above stated position being separated by almost the same distance from the four apertures (see FIG. 6). More specifically, a first aperture in the Y axis direction belonging in the odd-numbered column N 2n+1 is at a positionof Y=a N /2 and apertures are arrayed at a pitch a N from the firstaperture in parallel with the Y axis.
The vertical axis in FIG. 7A represents a gradual change of pitches a N of the apertures in the Y axis direction in relation to a 0 , while the horizontal axis represents the distance D X from the origin O to the Nth column. For example, a pitch a N in the column N is represented bythe following equation:
a.sub.N =a.sub.0 (1-K.sub.1 N.sup.2)
where preferably a 0 =0.368 mm and K 1 =7.59×10 -8 mm.
FIG. 7B is a diagram representing a gradual change of pitches b N of columns in the X axis direction. The vertical axis in FIG. 7B represents the change of pitches b N between the columns in relation to b 0 , while the horizontal axis represents the distance from the origin O to thecolumn N. More specifically, a distance between a column N and a column (N+1) is set to be increased as N becomes large. For example, the following equation can be specifically established:
b.sub.N =b.sub.0 (1+K.sub.2 N.sup.2)
where b 0 indicates the distance between the column (N=0) on the Y axisand the adjacent column (N=1 or N=-1) and preferably b 0 =0.554 mm, K 2 =3.06×10 -7 mm and b N =0.637 mm in the case where N=700.
As a specific example, in a corner of a 20-inch CRT for example, an angle between a line connecting the arrival points of a trio of electron beams and the X axis is approximately 3° to 6°. Generally, the inclination of a trio of electron beams is larger than the inclination of a trio of associated fluorescent dots and, therefore, the inclination of arow in the shadow mask is preferably 3° to 4°. The change of pitches a N shown in FIG. 7A serves to correct a difference of inclination angles in the trios of electron beams passing through the vertically adjacent apertures more effectively than possible in a conventional CRT such as the type depicted in FIG. 1. Furthermore, according to the present invention, a larger space can be obtained betweenthe respective trios of beams in the Y axis direction by making a pitch a N in the Y axis direction larger than is the case in a conventional CRT.
For the purpose of clarifying a difference between a shadow mask of the present invention and a conventional shadow mask, the following description will be made with reference to FIG. 8. Similarly to FIG. 6, FIG. 8 shows several apertures in the center and in a corner portion of a shadow mask. As shown in FIG. 8, the component in the Y axis direction, i.e., to the distance from the aperture at the origin O to the nearest aperture in the next row (M=1 or M=-1), is P YO (=a 0 /2) and the component in the X axis is P XO (=b 2 /2) which corresponds to thedistance between the columns N=0 and N=1 (or N=-1). Similarly, in a corner portion of the shadow mask, the components in the X axis direction and theY axis direction are defined as P YE =a N /2 and P XE =b N ,respectively. Although a row of apertures in a corner portion of the shadowmask is not strictly parallel to the X axis, such a row in FIG. 8 is shown as being parallel to the X axis for the purpose of making a clearer comparison with a row of apertures in the center. However, this does not affect the definition of P YE and P XE .
According to the definition in FIG. 8, in the array of apertures of the shadow mask as described in the above stated embodiment the following three relations are established. ##EQU1##
Regarding the three relations, the relation (3) serves principally to correct a difference in inclination angles in the vertically adjacent beamtrios and the relation (2) serves to take a sufficient spacing in the X axis direction.
The relation (1) has a meaning as described in the following. For a high resolution CRT (HRCRT), electron beams are required to be narrowly appliedand pitches of apertures in a shadow mask need to be small. On the other hand, since the close packed structure is conventionally adopted for an array of apertures of a shadow mask, the nearest three apertures form a regular triangle. In other words, a relation of P YO /P XO =1/√3 is established. Accordingly, the resolution of a HRCRT is lower in the X axis direction and P XO is regarded as a substantial resolving power. Considering this point also, the present invention intends to make an improved distribution of apertures. More specifically, since a relation of P YO =P XO /√3 is established in a conventional shadow mask and the overresolution in the vertical Y axis direction can give another capacity for further improvement, the present invention intends to utilize this capacity for improvement of the color purity. According to the present invention, P YE is always set to be smaller than P YO (for example, P YE =P YO -15 μm approximately in a corner portion) and, as a result, if a relation of P YE =P XE in a corner portion is regarded as a limit, the increase of P YO is limited to an increase of about 20% of P XO , similarly to the above stated relation (2). This limitation also serves for preventing characters and the like represented in a corner portion of a CRT from appearing differently as compared with the same characters and the like represented in the center.
FIG. 9A shows a gradual change in the pitches of apertures in case where the above stated relations (2) and (3) in accordance with the present invention are applied under the condition of P YO =P XO /√3. In FIG. 9A, the vertical axis represents pitches of apertures and the horizontal axis is related to the component in the X axis direction as to a distance from the center O of a shadow mask to an aperture. Although the change is practically made in a stepped form as shown in FIG. 7A, such change is represented as a smooth curve in FIG. 9A for simplification of the illustration.
FIG. 9B shows the similar change in the pitches of improved apertures, taking account of the relation (2) also. In FIG. 9B, the array of apertures is made so that P YO is, for example, set to P YO =P XO +5 (μm) and the pitch P YE in a corner portion is approached to P XE .
FIG. 10 is a diagram for explaining improvement of the space factor by the change of the pitch of apertures. Referring to FIG. 10, the horizontal axis represents percentages of the increase in the pitch of apertures and the vertical axis represents percentages (%) of the increase in the distance between the nearest arrival points of the electron beams. As shown in the drawing, the distance between the nearest arrival points of the beams becomes large in proportion to increase in the pitch of apertures so that the space factor is improved. For example, in case of P XO =0.3×(√3/2) and P XE =0.3×(√3/2)×1.15, in other words, in a case where the pitch in the X axis direction in a corner portion is increased by 15%, thespace factor in the horizontal direction becomes improved by 15% and the distance between the nearest arrival points of the electron beams becomes large by about 4%, for example, about 7 μm in a practical size of a corner portion of a 20-inch CRT.
In addition, since the pitch P YO of apertures in the Y axis direction in accordance with the present invention is made large within the range ofthe relation (1), this pitch may be, for example, 0.368/2 mm in FIG. 6, which is larger by about 15% than a pitch of 0.320/2 mm in the center of such a conventional CRT as in FIG. 1 and the distance between the nearest arrival points of the electron beams is improved by about 20 μm including the component improved in the X axis direction as described above.
The reason why such a great improvement can be obtained in the corner portion is that since there is conventionally an overresolution in the Y axis direction, and such overresolving power is reduced a little in the center, to give a capacity for improvement of the space factor in the corner portion. In contrast to an ordinary CRT, the brightness in the peripheral portions in a HRCRT becomes more important at the time of setting the brightness and, therefore, such a slight reduction in the resolving power in the center is permissible.
However, the increase of the pitch of apertures of the shadow mask in the Yaxis direction involves a disadvantage that if a "moire" is caused by interference between the increased pitch and the scanning distance of the electron beams, such moire will tend to appear perceptible. Generally, thepitch of apertures of the shadow mask in a HRCRT is so small and in the order of about 1/2 of the distance between the scanning lines of electron beams and, therefore, such increase of the pitch will practically cause noproblem.
As described previously, in the distribution of apertures of the shadow mask in FIG. 5, the rows of apertures in the X axis direction are in the shape of a barrel and the columns of apertures in the Y axis direction arein the shape of a pincushion, while in accordance with the present invention, only the rows of apertures in the X axis direction are in the shape of a barrel and all the columns of apertures are straight lines parallel to the Y axis. Accordingly, an array of apertures of a shadow mask in accordance with the present invention can be easily formed at a lower cost as compared with the array shown in FIG. 5. In an embodiment inFIG. 6, description was made of a case where the pitches of apertures (or columns) in the X axis direction were gradually made larger, as shown in FIG. 7B. However, such a case involves a disadvantage concerning the resolution if the pitch in the X axis direction becomes too large in a corner (or side) portion. Consequently, if the resolution in the X axis direction in a corner (or side) portion is a matter of importance, it goeswithout saying that the pitches may be set to satisfy the above stated relations (1) and (3) only in the Y axis direction with a fixed condition of P XE =P XO .
Although, in the foregoing embodiment, a case where the pitch of apertures in the Y axis direction in each column N was a fixed value of a N was described, this pitch need not always be set to the fixed value. It is important that the rows of apertures in the X axis direction be in the shape of a barrel and all the columns of apertures be straight lines parallel to the Y axis. In many cases, HRCRTs are utilized for representation of characters, graphs etc. In such cases, the tolerance of the pitch of apertures of the shadow mask in the Y axis direction is limited to about ±25 μm (a difference of 50 μm). In addition, as described previously, the correction of the pitch of apertures in the X axis direction is limited to about a 20% increase as compared with a conventional CRT. For example, if the pitch in the Y axis direction in theclose packed structure is 0.300 mm, the pitch in the X axis direction is approximately 0.52 mm and, where these values are selected in the center, it is made clear that the practical limit value of the pitch P XE in the X axis direction is approximately 0.62 mm. In the HRCRT, a remarkable improvement is made as to the distance between the nearest arrival points of the electron beams as shown in an embodiment of the present invention (approximately 20 μm in a corner portion of a 20-inch CRT). Further, the improvement makes it possible not only to enlarge the permissible landing tolerance of electron beams in the finished color CRTs but also tonoticeably improve the efficiency of manufacturing a fluorescent screen.
Although the present invention has been described and illustrated in detail, it should be clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation,the spirit and scope of the present invention being limited only by the terms of the appended claims.
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A color cathode-ray tube in accordance with the present invention comprises a set of three electron guns in an in-line array, a shadow mask with a curved surface having a plurality of circular small apertures and a fluorescent screen with a curved surface disposed in parallel with the above stated shadow mask and including fluorescent dots arrayed in association with three electron beams passing through the above stated small apertures. The above stated shadow mask includes, in the flat state before pressed to have the curved surface, the X axis through the center of the flat mask being horizontal in parallel with the direction of the above stated in-line array and the Y axis through the center being vertical to the X axis. Rows of the apertures in the X axis direction are curved more prominently in the shape of a barrel according to increase of the distance from the X axis and columns of the apertures in the Y axis direction are all straight lines parallel to the Y axis.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a railcar for shipping loose sheet material, e.g., glass sheets and/or crates and more particularly, to a railcar for shipping loose glass sheets that are loaded and/or unloaded from one side thereof.
2. Discussion of the Technical Problems
As is known, under certain conditions, it is more economical to ship loose glass sheets by railcar than by truck.
In general, the railcar for shipping loose glass sheets includes an "A" frame mounted in the center of a flat bed railcar or in a gondola railcar. Retaining facilities maintain the glass sheets against the "A" frame in a generally vertical position.
The above type of glass shipping railcars have drawbacks. More particularly, a crane with a high boom is used to load the railcar from one side. The boom has to be high enough to lift the glass sheets over the "A" frame and the sides of the gondola railcar when loading from one side only.
The use of a crane having a high boom is not practical for unloading railcars because the glass unloaded from the railcar has to be moved into a structure. Therefore other expediencies are used to unload railcar having "A" frames. One method is to remove the glass from one side, turn the railcar around and remove the glass from the other side.
Glass can be removed from gondola railcars having an "A" frame by raising the glass above the bed of the railcar and then moving the railcar relative to the raised glass until the side of the railcar clears the raised glass sheets.
As can be appreciated each time a railcar is moved an expense is incurred. It will be advantageous therefore if a railcar is available that does not have the drawbacks of the presently available railcars.
SUMMARY OF THE INVENTION
This invention relates to an improved railcar for shipping articles, e.g., loose glass sheets or crates. The railcar is of the type having a flat bed supported on a pair of spaced wheel carriages or trucks. The improvement includes a plurality of lateral runners secured on the flat bed in spaced relation to each other to provide a supporting surface spaced above the surface of the flat bed. A stanchion has one end secured to each of the lateral runners to provide a vertical supporting surface.
This invention also relates to a method of loading articles, e.g., loose glass sheets having a predetermined width, length and thickness on a railcar. A plurality of deck runners are secured on a flat bed of a railcar in predetermined spaced relationship to each other to provide a supporting surface above the surface of the bed of the railcar. A stanchion is secured to each of the deck runners such that the center of gravity of the stanchion and articles to be loaded is at the longitudinal center of the railcar. The articles are loaded on the deck runners and stanchion and secured thereto by restraining facilities to prevent lateral motion of the articles. Thereafter end restraints are secured to the bed of the railcar to prevent longitudinal motion of the articles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a railcar incorporating features of the invention;
FIG. 2 is a partial side view of the railcar of FIG. 1;
FIG. 3 is a view similar to FIG. 2 showing the railcar of the invention loaded with glass sheets and crates to be shipped;
FIG. 4 is a view taken along lines 4--4 of FIG. 3;
FIG. 5 is a view taken along lines 5--5 of FIG. 3;
FIG. 6 is a plan view of a deck runner incorporating features of the invention;
FIG. 7 is a side view of the deck runners of FIG. 6;
FIG. 8 is a side view of a stanchion incorporating features of the invention;
FIG. 9 is a front view of the stanchion of FIG. 8;
FIG. 10 is a view taken along lines 10--10 of FIG. 8 and having portions removed for purposes of clarity;
FIG. 11 is a front view of a lash bar incorporating features of the invention;
FIG. 12 is a plan view of an end restraint incorporating features of the invention;
FIG. 13 is a view taken along lines 13--13 of FIG. 12;
FIG. 14 is a side view of the railcar of the invention provided with a telescoping cover incorporating features of the invention;
FIG. 15 is a view taken along lines 15--15 of FIG. 14; and
FIGS. 16, 17 and 18 are sectional views having portions removed for purposes of clarity illustrating the sealing of the sections of telescoping cover shown in FIG. 14.
BRIEF DESCRIPTION OF THE INVENTION
In general, this invention relates to a railcar for shipping loose sheet material and/or crates that is easy and economical to load and/or unload.
With reference to FIGS. 1 and 2, railcar 20 incorporating features of the invention includes a flat bed 22 having a pair of spaced bulkheads 23 and supported in any conventional manner at opposed ends by a wheel carriage or trucks 24 (one shown in FIG. 2). The flat bed 22, bulkheads 23 and wheel carriages 24 are of the type used in the railcar art and are not limiting to the invention.
Mounted on the flat bed 22 are a plurality of deck or floor runners 26 each having a stanchion 28 for supporting loose sheet material 30, e.g., loose glass sheets and/or crates 32, e.g., glass packing crates as shown in FIGS. 3, 4, and 5.
With reference to FIGS. 6 and 7 the deck runners 26 each include a pair of side members 34 held in spaced relation by a pair of end plate members 36 to slideably receive an end of the stanchion 28 in a manner to be discussed below. The deck runners 26 are detachably secured on the flat bed 22 in any conventional manner to accommodate various lengths of sheets 30 and/or crates 32. For example, but not limiting to the invention, a pair of rigid longitudinal members 38 are secured to the bed 22 of the railcar 20 in spaced relation to receive the deck runners 26 therebetween as shown in FIGS. 1, 4 and 5.
With reference to FIGS. 4, 5, 6, and 7 the end plates 36 of the deck runners 26 and the rigid longitudinal members 38 are each provided with a plurality of holes 40 and 42, respectively, which are aligned to receive a nut and bolt or pin arrangement 44 (one shown in FIG. 4) to detachably secure the deck runner 26 between the rigid longitudinal members 38.
As can now be appreciated the deck runners 26 may be detachably secured directly to the flat bed 22 of the railcar 20. In the alternative, selected ones of the deck runners may be secured in place as by welding and plates 36 of the runners 26 to the longitudinal members 38.
Referring to FIGS. 8, 9 and 10, there is shown a preferred structure of the stanchions 26 that provide vertical support for the glass sheets 30 and crates 32 as shown in FIGS. 4 and 5. The stanchions 26 are constructed to give maximum stability while minimizing weight because increased weight of the stanchions reduces the allowable load to be shipped.
A stanchion 26 includes an engaging surface plate 46, side plates 48 and 50 and a backwall 52 joined together by angle irons 54. A portion of the backwall 52 has a groove 58 formed by a pair of angle irons 59 for receiving a restraining strap 60, shown in FIGS. 4 and 5, in a manner to be discussed below. The remaining portion of the backwall includes a plate 62.
The engaging surface 46 is preferably at an oblique angle to the plane of the deck runners 26 to provide packing stability and minimize small oscillatory forces that tend to move the sheets 30 about their supported edge 64 toward and away from the stanchions 26.
With specific reference to FIG. 9, opposed side plates 48 and 50 have a portion 66 and 67, respectively, insertable between the side members 34 of the deck runner 26 as shown in FIGS. 4 and 5. The stanchion 26 is detachably secured to the deck runners 26 by providing holes 68 in lower portions 66 and 67 of sides 48 and 50, respectively, of the stanchion and side holes 69 in the side members 34 of the deck runner 26 (see FIGS. 6 and 7). The holes 66 and 67 are aligned with the side holes 69 to receive a nut and bolt or pin assembly 70 as shown in FIGS. 4 and 5.
A supporting member 72 is preferably secured to each of the side plates 48 and 50 as shown in FIGS. 8 and 9 to support the stanchion 28 on the members 34 of the floor runner 26 to aid in sliding the stanchion along the floor runner 26 to align the holes and to reduce the shearing force acting on the nut and bolt assembly 70. A gusset plate 74 is secured adjacent the bottom of the stanchion as shown in FIGS. 4, 5, and 8 to provide additional structural stability to the stanchion 28.
The stanchions 28 are secured on the deck runners 26 such that the center of gravity of the load is at the longitudinal center of the railcar 26. Although in the preferred embodiment the stanchions 28 are detachably secured to the deck runners 26 for adjustment for various loads the invention is not limited thereto. For example, the stanchions may be permanently secured to the deck runners 26 adjacent an end of the runners. In this instance the center of gravity of the load is positioned at the longitudinal center of the railcar by building up the stanchion using dunnage, e.g., wood.
As shown in FIGS. 2, 8 and 9 each of the side plates 48 and 50 of the stanchions 28 are provided with a bifurcated member 76 for receiving an end of a turnbuckle 78. The turnbuckle provides structural stability to the stanchions when the railcar is empty.
The glass sheets 30 are loaded on the railcar using a sling and spreader bar assembly of the type used in the art, e.g., sold by Liftall of St. Manheim, Pa. The deck runners 26 maintain the supported edge 64 of the sheets 30 above the flat bed 22 of the railcar 20 to facilitate applying and/or removing the sling to the edges of the glass sheets.
With reference to FIGS. 3 and 5, the crates 30 are loaded on the railcar 20 by providing a raised floor 82 such that the supporting surface 46 of the stanchion 28 is normal to the raised floor 82. In this manner, the crates are supported at the bottom surface and back surface as shown in FIG. 5.
The railcar 20 of the instant invention is completely loaded and unloaded from one side thereby eliminating the drawbacks of the prior art railcars having an "A" frame mounted on a flat bed. More particularly, in the prior art, the railcar was unloaded from one side, and thereafter the railcar was turned around to unload from the other side. With the railcar of the instant invention, the railcar can be unloaded from one side thereby eliminating the time delay and economic drawbacks associated with turning the railcar around to unload same.
The discussion will now be directed to the restraining system to prevent movement of the sheets during shipment. With reference to FIGS. 4, 5, and 11, oscillatory motion of the sheets about the edge 64 and lateral motion of the sheets toward and away from the stanchions 28 is prevented by a lash bar 84 and the restraining strap 60. The lash bar 84 includes a pair of spaced elongated members 86 joined by struts 88.
With specific reference to FIGS. 4 and 5, the strap 60 has a looped end 90 secured between the side members 34 of the deck runners 26 by a pin 92. The course of the strap is around the outer surface of the struts 88 over the top of the sheets 30 or crates 32, through the stanchion 28 by way of holes 94 (see FIG. 9) over member 96 in the groove 58 of the stanchion 28 with the other end of the strap 60 secured to ratchet assembly 98 mounted on the backwall 52 of the stanchion 28 as shown in FIG. 8. Applying tension to the strap 60 by way of the ratchet assembly 98 urges the lash bar 84 and sheets 30 or crate 32 against the stanchion 28.
The lash bar 84 of the instant invention minimizes corner pressures on the glass sheets because the pressure is put on the struts 88. Further the lash bar 84 can be used for various load heights because of the spaced struts 88.
Longitudinal movement of the sheets 30 or crates 32 is prevented by end restraint 100 positioned on each side of the sheets or crates as shown in FIG. 3.
Referring to FIGS. 12 and 13 the end restraint 100 includes an H or I shaped beam 102 having L shaped plates 104 at each end. Legs 106 of the plates 104 are provided with a series of holes 108 that are alignable with holes 110 of the longitudinal members 38 to receive a nut and bolt or pin assembly (not shown). A pair of spaced lift plates 112 are secured to the beam 102 to facilitate moving and positioning of the end restraint.
When the end restraint is slightly spaced from the ends of the glass sheets because of hole arrangement, dunnage such as wood may be used to minimize longitudinal movement of the sheets or crates.
As can be appreciated, when the sheets shipped are glass sheets, the contacting surfaces of the stanchions, lash bars, end restraint and deck runners are preferably provided with resilient material, e.g., rubber to prevent marring of the glass. In the instance of the end restraint it is preferred to use dunnage, e.g., wood between the beam 102 and edges of the glass. This is because the greatest force acting on the glass is in a direction parallel to the travel of the railcar, e.g., the longitudinal motion of the sheets.
The invention is not limited to the number of stanchions or deck runners used. However it is recommended that for glass sheets the distance between stanchions be less than about 3 feet (0.9 meter) to minimize bending moments acting on the glass sheets.
In the instance where the sheet material is effected by the weather, e.g., rain, sun or snow a cover should be provided. The cover may be any of the types used in the art. Shown in FIG. 14 is a preferred rigid cover 120. The cover 120 includes an outer right cover portion 122, an inner right cover portion 124, an inner left cover portion 126 and an outer left cover portion 128 slideably mounted on the flat bed 22 of the railcar 20.
The cover portions each have an inverted U-shaped configuration and sized such that the inner right cover portion 124 is slideable under the outer right cover portion 122 and the inner left cover portion 126 is slideable under the outer left cover portion 128. In this manner approximately 25 percent to 50 percent of the interior of the railcar is accessible at one time.
With reference to FIG. 15, the outer cover portions 122 and 128 are slideably mounted on a guideway 130 and the inner cover portions 124 and 126 are slideably mounted on guiderail 132 by way of wheels 134 and 136, respectively, mounted in housing 138 and 140, respectively. The guiderails 130 and 132 are mounted on the outside of the longitudinal members 38. The housing is attached to legs 142 and 144 of the outer and inner cover portions 122, 128 and 124, 126 respectively as shown in FIG. 15 for cover portions 122 and 124.
A T-shaped member 146 is mounted between the guiderails 130 and 132 and over flanges 147 extending outward from the housings 140 and 142 as shown in FIG. 15 to maintain the covers on the railcar and to prevent water from splashing into the interior of the railcar.
Moisture is prevented from moving under the cover 120 by providing a resilient strip 148, e.g., rubber between the bulkheads 23 adjacent ends of the outer cover plate 122 and 128 as shown in FIG. 16 for the left side of railcar 20. The outer cover plates are urged against the adjacent bulkhead and held in position by a locking mechanism 149 of the type used in the art as shown in FIG. 14. The adjacent ends of the outer cover portions 122 and 128 and inner covers 124 and 126 are sealed by extending outer edge portion 150 of the outer cover plates inward and outer edge portion 152 of the inner cover plates outward as shown in FIG. 17 for cover portions 126 and 128. A resilient strip 154 is adhered to the inner wall of the outer cover portion 128 and compressed by the end 152 of the inner cover portions 126.
Adjacent ends of the inner cover portions 124 and 126 are sealed by forming the adjacent ends of the inner cover portions such that the end 156 of left inner cover portion 126 slides under the end 158 of the inner right cover portion 124 into engagement with a resilient pad 160 mounted on the inner wall of the inner right cover portion 124 as shown in FIG. 18.
A locking mechanism 160 similar to locking mechanism 149 urges the inner cover portions together to compress the resilient pad 160 and urges the inner cover plates away from their adjacent outer cover portions to compress the resilient strip 154.
As can be appreciated the invention is not limited to the construction of the cover 120 and that the construction of the cover can be modified within the scope of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The railcar of the instant invention will be used to ship 80 loose glass sheets having dimensions of 130 inches (3.3 meters) × 168 inches (4.2 meters) × 1/4 inch (0.635 centimeter) (hereinafter referred to as Group A glass sheets); 156 loose glass sheets having dimensions of 130 inches (3.3 meters) × 144 inches (3.7 meters) × 1/4 inch (0.635 centimeter) (hereinafter referred to as Group B) glass sheets) and 8 crates of glass sheets having a parallelpiped shape and dimensions of 80 inches (2.0 meters) × 100 inches (2.5 meters) × 7 inches (17.8 centimeters).
With reference to FIG. 1, a railcar 20 has a flat bed 22 having dimensions of 60 feet (18.2 meters) × 101/2 feet (3.2 meters) supported on wheel carriages 24 or trucks of the type used in the art has a pair of spaced bulkheads 23 secured to the bed. A pair of "C" shaped longitudinal members 38 (AISC MC7 × 19.1) having a length of about 481/2 feet (14.8 meters) and spaced about 8-1/6 feet (2.4 meters) apart are secured to the flat bed of the car between the bulkheads. The members 38 are provided with 5/16 inch (7.8 millimeters) diameter holes 42 in the central portion and holes 110 in the upper leg on a center-to-center spacing of 6 inches (17 centimeters) as shown in FIGS. 4 and 5.
With reference to FIG. 15, a pair of guiderails 130 and 132, 481/2 feet (14.8 meters) in length are secured to the bed of the railcar and spaced 5 inches (12.5 centimeters) and 2 inches (5.08 centimeters), respectively, from the adjacent member 38. The guiderails are made of 11/2 inch (3.9 centimeters) × 11/2 inch (3.9 centimeters) angle iron 3/16 inch (5 millimeters) thick.
A pair of outer cover portions 122 and 128 and inner cover portions 124 and 126 having an inverted U-shaped are slideably mounted on the guiderail by wheels 134 and 136. The wheels 134 and 132 are rotatably mounted in housing 138 and 140, attached to sides 142 and 144 of the cover portions 122 and 128 and 124, 126, respectively, (one side only shown in FIG. 15). A 1/4 inch (0.62 centimeter) thick "T" shaped plate 146 is mounted between the guiderails 130 and 132 and flanges 147 extending from housings 138 and 140.
The outer cover portions 122 and 128 are made of fiber glass and have a length of 121/2 feet (3.8 meters), a height of 15 feet (4.6 meters) at their highest point and sides spaced 9-2/3 feet (2.9 meters). The inner cover portions 124 and 126 are also made of fiber glass and have a length of 121/2 feet (3.8 meters), a height of 141/2 feet (4.4 meters) at their highest point and sides spaced 8-5/6 feet (2.7 meters) apart such that the inner cover portions 124 and 126 are slideable in the outer cover portions 122 and 128.
With reference to FIG. 17, end 152 of the inner cover portions 124 and 126 is captured in adjacent end 150 of adjacent outer cover portion 122 and 128, respectively, by providing that the end 150 of the outer cover portions 122 and 128 is angled toward the inner cover portions 124 and 126 and the end 152 of the inner cover portions 124 and 126 is angled toward the outer cover portions as shown in FIG. 17 for cover portions 126 and 128. A strip of rubber 154 is provided in the area where the end 152 of the inner cover portion 124 and 126 engages the outer cover portions 122 and 128.
As shown in FIG. 16, a rubber strip 148 is secured to the bulkhead 23 and engaged by the end of the outer cover portion 122. A similar arrangement is provided at the other end of the railcar 20.
The adjacent ends 156 and 158 of the inner cover portions 126 and 128, respectively, slide over one another as shown in FIG. 18 with the end 156 of the left inner cover portion 126 engaging a rubber pad 160 mounted on the inner surface of the inner cover portion 124 as shown in FIG. 18.
Referring now to FIGS. 1, 6 and 7, a plurality of deck runners 26 are mounted between the rigid longitudinal members 38. Each deck runner 26 includes a pair of AISC MC7 × 19.1 steel channels 34 joined at their ends by an end plate 36. The channels 34 are 81/2 feet (2.4 meters) in length and spaced 1 foot (0.3 meter) apart. The end plates 36 are made of 3/8 inch (0.95 centimeter) thick steel having dimensions of 65/8 inches (17 centimeters) × 2 feet (0.6 meter). The end plates have 1/4 inch (0.63 centimeter) holes 40 which are alignable with hole 110 of the longitudinal runners 38 to receive nut and bolt assembly 44 to secure the deck runners in position as shown in FIGS. 4 and 5.
With reference to FIG. 2, a stanchion 28 is mounted on each of the deck runners. As shown in FIGS. 8, 9 and 10 each of the stanchions are 11 feet (3.3 meters) high and include a 1/4 inch (0.63 centimeter) thick steel plates 46, 48, 50 and 62 joined together by 1/4 inch (0.63 centimeter) thick 3 inch (7.62 centimeters) × 3 inches (7.62 centimeters) steel angle irons 54. The top end of the stanchion 28 viewed in FIGS. 8 and 9 have dimensions of 1 foot (0.3 meter) by 9 inches (0.2 meter) and dimensions of 1 foot (0.3 meter) by 12/3 feet (0.5 meter) at 164 adjacent the bottom end to provide a 5° slope to the engaging surface plate 46 of the stanchion 28.
A guideway or channel 58, 45/8 inches (11.8 centimeters) wide and 6 feet (1.2 meters) is provided on the back or left side of the stanchion as the stanchion is viewed in FIGS. 8 and 10. Steel tubing 96, 1/4 inch (0.63 centimeter) thick and 21/2 inches (6.4 centimeters) × 11/4 inches (3.2 centimeters) on a center-to-center spacing of 1 foot (0.3 meter) is provided in the guideway 58 to define the course of the retaining strap 60 as shown in FIGS. 4 and 5. A rachet device 98 of the type used in the art is mounted below the guideway 58.
A portion 67 of the side plates 48 and 50 extend 5 inches (12.7 centimeters) beyond the plates 62 and 46 and are insertable in the deck runners 26. Holes 68 in the portions 67 and 1/4 inch (0.62 centimeter) in diameter, on a center-to-center spacing of 3 inches (7.6 centimeters) are alignable with holes 69 of the deck runners (see FIGS. 6 and 7) to receive a nut and bolt assembly 70 as shown in FIGS. 4 and 5.
With reference to FIGS. 8 and 9, 11/4 inches (3.8 centimeters) × 1 inch (2.54 centimeters) and 1 foot (0.3 meter) long steel member 72 is secured to the sides 48 and 50 of the stanchion 28 at 164 to aid in sliding the stanchion along the deck runners 28 and reduce shearing forces acting on the nut and bolt assembly 70. Holes 94, 8 inches (20 centimeters) × 4 inches (10 centimeters) are provided in the plate 46 for passing the restraining strap 60 through the stanchion to the guideway 58.
Steel gussets 74 made of 1/4 inch (0.63 centimeter) thick steel triangular plates having a base of 41/2 inches (11.3 centimeters) by 2 feet (0.6 meter) high are secured to each side of the stanchion 28 as shown in FIG. 8.
The engaging surface or the plate 46 and the engaging surface of the deck runners 26 is provided with rubber (not shown) to prevent marring of the glass sheets to be loaded.
Provided on each side plate 48 and 50 of the stanchion is a bifurcated member 76 for receiving one end of a turnbuckle 78 (see FIG. 2) of the type used in the art to provide structural stability for aligned stanchions when the railcar is empty.
The discussion will now be directed to loading the Group A glass sheets on the left side of the railcar 20 as viewed in FIGS. 1 and 14. The cover portions 124, 126, and 128 are slid to the right end of the railcar 22 as viewed in FIG. 14.
With reference to FIGS. 3, 12 and 13, an end restraint 100 having a W12 × 65 shaped beam 72/3 feet (2.3 meters) long and 1/2 inch (1.27 centimeters) thick steel L-shaped plates 104 on each end is mounted adjacent the left bulkhead 23 as viewed in FIG. 1. The legs 106 of the plate 104 is 31/2 inches (8.8 centimeters) wide 2 feet (0.6 meters) long and is provided with 1/4 inch (0.63 centimeter) holes 108 which are alignable with holes 110 of the longitudinal members 38 to a receiving nut and bolt assembly.
The stanchion 28 and deck runner 26 assembly is spaced 8 inches (20 centimeters) from the end restraint 100. Thereafter 4 stanchions 28 and deck runner 26 assemblies are secured in place on a 3 foot (0.9 meter) center-to-center spacing.
Each of the stanchions 28 are spaced 1 foot (0.3 meter) from the longitudinal center of the railcar to position the center of gravity of the Group A sheet at the longitudinal center of the railcar.
Dunnage, e.g., wood, is positioned against the end restraint and the glass sheets are loaded onto the deck runners in packs of 20 using a sling and spreader bar of the type known in the art. A 11/2 inch (3.7 centimeters) thick polyethylene strip (not shown) is placed between each pack to facilitate removal and insertion of the slings to unload the glass sheets. The glass sheets are supported in a vertical position with the bottom edge 64 resting on the deck runners 26 and the stanchions maintaining the glass sheets in the vertical position as shown in FIG. 4.
An end restraint 100 is then secured on the longitudinal members 38 with dunnage between the end restraints and glass.
With reference to FIG. 4, looped end 90 of restraining strap 60 is secured in each of the deck runners 28 by a pin 92.
With reference to FIGS. 4 and 11, a lash bar 84 has an end mounted in each of the deck runners 26. The lash bar includes a pair of 111/2 feet (34 meters) long 1/4 inch (0.63 centimeter) thick 4 inches (10 centimeters) × 4 inches (10 centimeters) aluminum tubing 86 held in spaced relation by a plurality of 111/2 inches (0.3 meter) long, 1 inch (2.54 centimeters) inside diameter, 1/4 inch (0.63 centimeter) thick aluminum tubing spaced 1 foot (0.3 meter) apart. Foam rubber (not shown) is provided between the lash bar and glass sheets.
With reference to FIG. 4, the strap 60 has its course over the outer surfaces of the tubing 88 over the glass sheets through the stanchion over the member 96 in the guideway 58 and has the end secured to the ratchet 98. Rotating the ratchet in a first direction urges the lash bars and glass sheets against the stanchion.
The end restraints prevent longitudinal motion of the glass sheets during shipment.
The cover portions 122, 124, 126 and 128 are slid to the left side of the railcar to load the Group B sheets on the right side of the railcar as viewed in FIGS. 1 and 14.
The Group B glass sheets are loaded in a similar manner as the Group A glass sheets except the supporting surface of the stanchions are spaced 2 feet (0.6 meter) from the longitudinal center of the railcar and stacks of 26 sheets are loaded and separated by spacers.
The outer and inner right cover portions 122 and 124, respectively, are slid to the right to load the crates 32 about the lateral center of the railcar. Three stanchion and deck runner 26 assemblies are spaced 3 feet (0.9 meter) apart about the lateral center of the railcar. The stanchions 28 are spaced 2 2/3 feet (0.8 meter) from the longitudinal center of the railcar. Thereafter a floor, e.g., a wooden floor 82 is mounted on the deck runners such that the surface of the floor 82 and the supporting surface of the stanchion form a 90 degree angle as shown in FIG. 5. The end restraints and lash bars are applied as previously discussed for the glass sheets to secure the crates to the railcar.
With reference to FIG. 14, the outer cover portions 122 and 128 are secured to their adjacent bulkhead 23 by locking mechanism 162 and adjacent ends of the inner cover portions are held together by locking mechanism 162. The railcar is now ready for shipment.
The glass sheets and crates are unloaded in the reverse manner in which they were loaded but not necessarily in that order.
The invention is not limited to the specific example discussed and the example was presented for illustration purposes only.
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A railcar for shipping loose glass sheets includes moveable deck runners each having a moveable stanchion to support the sheets in a generally vertical position. The railcar is loaded and/or unloaded from one side. The glass sheets are protected from the weather during shipping and storing by a telescoping fiber glass cover.
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This application is a divisional application of application Ser. No. 889,016 filed Mar. 22, 1978 now U.S. Pat. No. 4,307,897.
BACKGROUND OF THE INVENTION
The provision of preprinted forms in an interconnected manifold set or layered assembly, composed of record forms, carbonless copying sheets, or record sheets with transfer sheets or carbons interleaved therebetween, is customary in modern business practice. It has been found most efficient to produce this type of assembly in a continuous form wherein the layered assembly is made severable along its length into a plurality of separate units by transverse perforations and also, by virtue of which, these units, corresponding to manifold sets of separate forms, are capable of being stacked conveniently in continuous zig-zag manner, for storage or transport.
Surface deformation in the several superimposed sheets of each assembly of the zig-zag stack will, unless some provision is made for flexible movement of the member sheets with respect to each other, tend to occur with consequent damage or distortion of the stacked or rolled assemblies. Deformation of the manifold assemblies of superimposed business forms, where the interconnection between the several sheets of the assembly is fixed or rigid, will also occur where the layered assemblies are forced about the feed rolls or cylindrical platens of varying diameters occurring in the many different business machines, including, for example, mini-computers, with which they are used increasingly. But whatever the particular deformation, either in storage, handling or use, the individual sheets or webs, tend, in this event, to shift longitudinally with relation to each other and must be free to do so. This interconnection or fastening of individual sheets in layered assembly occurs conventionally along the lateral margins of the superimposed sheets or webs using a variety of adhesive, crimping, and other techniques well-known to those skilled in the art.
Accordingly, if gluing, or other conventional, but less frequently employed means, such as stitching, stapling (which is capable of causing serious injury to a computer mechanism in which the manifold assembly is used), or the like, is employed to effect an immovable or inflexible fastening in which the superimposed sheets cannot shift longitudinally in relation to one another along the lateral margins of the superimposed sheets they cannot be folded or bent without buckling, distortion or even tearing of the forms. This much is well-recognized in the art and various means have been used or suggested to provide a more flexible fastening means capable of maintaining the condition of alignment of the assembled forms while accommodating the need for a longitudinal shift and a consequent, but reversible, misalignment to accompany deformation. At the same time, attempts have been made to reduce the bulkiness introduced into the assembly by gluing, stitching and other interlocking expedients incorporating foreign materials and rigidity into the assembly.
One means for maintaining the sheets or manifold assemblies in the necessary condition of alignment, while leaving the individual webs free to undergo shifting movement to avoid damage and internal stress, provides a series of crimps in the lateral margins of the assembly sheets. These crimps take the form of a series of marginal tabs or tongues, the free ends of which are depressed from the plane of the individual sheets to form interlocks based on this displacement. This expedient lacks permanence and stress tends to separate the several superimposed layers of an assembly so interconnected.
Another approach which is uniquely adaptable to manifolds, including record sheets and interleaved transfer or carbon copies, is that in which adjacent forms or record sheets bear continuous glue streams. The alternating transfer or carbon sheets, usually of relatively fragile integrity are bonded by means of the adhesive to both the underlying and overlying record sheets or strips using the foregoing glue streams. One or more series of marginal stress-relieving slits are provided in certain embodiments of this construction in the margin of the carbon sheets adjacent the paths of the record strip bonds to afford the desired adjustment to shifting. This construction thus retains the disadvantages, particularly of bulk and rigidity, of a more or less continuous glue stream and is, in any event, advantageously employed, it is believed, only where carbons are alternately interleaved in the manifold assembly. Additional disadvantages inherent in this latter expedient are the requirement of special and onerous additional production steps and equipment to make the stress-relieving slits in the carbon sheets, which results in additional expense in production of the forms and which, at the same time, weakens the carbon construction and renders it vulnerable to stress and damage by tearing and the like.
A further expedient proposed heretofore employs a combination of tab-formation and adhesive wherein a tongue is struck up from one exterior sheet vertically through holes provided in registry in the one or more intermediate sheets to pass outwardly onto the outer surface of the opposite exterior sheet to which the tab is made to adhere by gluing of the underside of the tab to the surface of the sheet. The tab may be further extended to double-back through a second series of orifices, as well. A further embodiment of similar aspect, described heretofore, suggests that the tabs lanced from one exterior sheet of an assembly be glued along their free underlying surfaces, after passing through a series of holes in registry in the intermediate sheets, to the interior surface of the opposing exterior sheet. The opposing exterior sheet is otherwise unmodified for this purpose. Alternatively, tabs may be formed on the opposing exterior sheets and made to pass through the holes of the intermediate sheets to adhere to the opposite surface of a centrally disposed sheet in the assembly. This latter sheet is unmodified for the purpose of forming an interlock, except for the adhesive disposed on its opposite surfaces between the fastening tabs.
The latter expedients require several additional steps and apparatus in preparation; for example, one or more punch units for the tab or tabs of each fastening point, a punch unit for the holes of the intermediate sheets or web and one or more special pressure units to push the tab or tabs through the holes in combination with a glue device. Further, the foregoing tab connectors are not adapted to permit the release of single sheets in series from the assemblies.
In the event, therefore, that means could be devised which would provide for high speed production of manifold assemblies, the superimposed sheets of which were fastened to one another by a combination of crimping and adhesive and in which the adhesive is used in minimal amounts consistent with the optional separation or decollation from the assembly of individual sheets and in which each crimp fastening required only a single crimp module, in combination with a single glue device while permitting the requisite alignment, and longitudinal shifting during assembly deformation, a significant advance in the state of the art would be attained.
It is, accordingly, an object of this invention to provide a plurality of continuous superimposed webs or sheets of flexible material, flexibly and permanently interconnected in manifold assemblies in a condition of alignment which permits the individual sheets to engage in, at least, a longitudinal shifting movement with respect to one another when the planar configuration of the assembly is disturbed to avoid stress and damage to the assembly and a return to a position of alignment when the planar state is restored.
It is a further object of this invention to provide manifold assemblies from which individual sheets or forms can be severed in series or decollated without materially affecting the fastening of the remaining sheets or forms therein.
It is still a further object of this invention to provide a high speed method and correspondingly efficient conventional apparatus with minimal but significant modification for producing the interlocked manifold assembly of the invention.
SUMMARY OF THE INVENTION
This invention provides accordingly, a manifold assembly composed of a plurality of overlapping or superimposed flexible sheets normally made of paper, including carbon interleaved and carbonless forms in a continuous assembly, including a pair of outer or exterior means for fastening said sheets in planar alignment while permitting a reversible stress-relieving longitudinal shifting of said sheets with respect to each other in response to distortion of the planar disposition of the assembly. The foregoing fastening means comprises a plurality of crimps or crimp legs in registry and struck or lanced from one of said exterior sheets, and said one or more interior sheets, where present; the free terminal margins of said crimps having adhesive coated thereon and joined to the interior surface of the other of said exterior sheets. The invention encompasses, as well, the method and apparatus for production of these manifold assemblies wherein the foregoing tabs are struck by a forming die or blade commonly known as a crimping module mounted in the collating apparatus in which the continuous manifold sheets are formed so that the free distal or terminal margins of each of said crimps or crimp legs extend below the plane of the assembled sheets in which the crimps or crimp legs are provided; the crimps being depressed from the plane of the assembly by an angle less than normal to said plane and so disposed as to present their free terminal or distal margins longitudinally, that is in the machine direction of said assembly through said collating apparatus to permit application of glue or other adhesive, from an adhesive applicator, to said free extreme distal margins or edges of each of said crimps to effect their merger, and bring the remaining exterior sheet or web into contact with the surface provided by said merged terminal margins of said crimps while the adhesive applied thereto is still tacky and capable of adhering to the surface of said remaining exterior sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and additional objects, features and advantages of this invention will be apparent to those skilled in the art from the following detailed description of the preferred embodiments of the invention when taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic side elevational view of apparatus for carrying out the process of the present invention;
FIG. 2 is a fragmentary schematic side elevational view showing the crimping module and adhesive applicator of FIG. 1 in greater detail;
FIG. 3 is a side elevational view of the crimping module, or station, part being broken away to show the device and its operation in even greater detail;
FIG. 4 is a fragmentary side elevational view of the adhesive applicator or glue device showing the manner in which the crimps are secured to an underlying exterior ply or sheet joined by the layered assembly.
FIG. 5 is a perspective view of a manifold assembly of the present invention;
FIG. 6 is a fragmentary perspective view of the encircled portion of the manifold assembly shown in FIG. 5 expanded to show the interlocking mechanism of the invention; and
FIG. 7 is a fragmentary longitudinal sectional view of the manifold assembly shown in FIGS. 5 and 6 taken along the lines 7--7 of FIG. 5 and expanded to better illustrate the interlocking mechanism of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The process of the present invention will be described in detail with particular reference to an apparatus such as shown in FIG. 1 for carrying out the process, and incorporating the mechanism, according to the invention. In general, then, a collating machine incorporating these inventive features is provided with a plurality of horizontally disposed cantilevered spindles or arbors 20 rotatably mounted on a frame (not shown). These arbors 20 are adapted to receive a number of rolls 22 of continuous flexible sheet or web substrate or material 24, and in a preferred embodiment, preprinted webs or record sheets, for example, preprinted paper business forms bearing stub punched aligner and pinfeed holes 25 spaced at regular intervals along at least one of their margins and adjacemt and interior thereof, longitudinally disposed stub perforations 27 (see FIGS. 5 and 6). These sheets or webs are fed, in a synchronized manner, according to standard procedures, about the dancers or rolls 26 which are adapted to control braking of the feed mechanism and spacing of the continuous web or continuous sheet 24 transmitted from the rolls 20.
Mounted, optionally in the practice herein described, on a second set of cantilevered rotatably mounted and horizontally disposed arbors 30 are rolls 32 of transfer sheets or carbon paper, the webs or sheets 34 of which are unrolled and fed about the idler or dancer rolls 36 which serve as braking and spacing means in the same manner as described with respect to the record sheet dancer rolls 26.
In the embodiment of FIG. 1, the webs or sheets are fed from the rolls 22 and 32 in a counterclockwise manner. It will be evident that the method of release, whether clockwise or counterclockwise, is one of choice and not critical to the invention described herein. The rolls 26, 30 and 36 are all mounted on the frame (not shown) upon which the spindles 20 are disposed and in a similar manner. The record sheets 24, and, where present, the transfer sheets 34 pass upwardly about the idler rolls 36 and 38 respectively, used to assure appropriate spacing of the webs with respect to one another, and thence through the respective cantilevered pairs of tensioning bars 40 and 42.
It will be obvious to those skilled in the art that the assembly of the record, and transfer sheets or webs where present, can take place from above, using for example, a standard Hamilton collator configuration (manufactured by Hamilton Tool Company, Hamilton, Ohio) without departing from the scope or spirit of the present invention.
From the tensioning bars which act as paper guides, the record webs 24 and transfer webs 34 pass about the synchronized, power-driven pinfeed cylinders 46, 48, 50, 52, 54 and 56. In alternative embodiments, readily apparent to those skilled in the art, the foregoing webs drop upon the cyllinders or a pinfeed band where assembled from above; or pass about a band such as the foregoing used in place of the foregoing pinfeed cylinders. The cylinders, as shown, contain a series of evenly spaced normally retractable pins 58, or alternatively pin bands (not shown) about one end to engage the marginal equally spaced aligner and pinfeed holes 25, referred to hereinabove, formed conventionally in the record and transfer webs prior to mounting upon the spindles 20 and 30 for assembly in registry in the assembly 62 on the pinfeed cylinders, thus assuring alignment of successive sheets, webs or plies and obviating slippage amoung the individual sheets of the assembly 62 and the cylinders. As shown in FIG. 1, transfer sheets are interposed only on the intermediate pinfeed cylinders 48, 50 and 52, so that they will alternate with record sheets in the assembly 62 with, however, record sheets occurring as the two exterior webs in the finally formed manifold 64 prior to transverse perforation thereof. It is within the contemplation of this invention, as noted elsewhere herein, that only two webs or plies may be placed in superimposed assembly, if desired.
The collating apparatus and method as thus far described are standard and well-known to those skilled in the art to which this invention pertains. Many conventional variations of this equipment, some of which are referred to elsewhere herein, may be employed without departing from the scope of the invention contemplated in connection therewith.
Referring now to FIG. 1, in conjunction with FIGS. 2 and 3, of the drawing, there is shown mounted upon the frame of the collating apparatus, a rotatable crimping module or unit 70 composed of a male die element comprising a crimp holder ring 72 bearing crimping blades or punches 74 at regular intervals sufficient to impress or strike a plurality of crimps in each severable form 66 to be produced from the assembly 62 longitudinally in the web or machine direction, and normally within a range of once every one-half inch to once every four inches, and occurs preferably once each half-inch to once every two inches. While a series of these crimps may be disposed in a cross-machine pattern or longitudinally in the machine direction at any series of points across the web surface of the assembly, it is usual and generally most convenient to define the crimps or crimp legs in at least one or both of the lateral margins of the assembly sheets in the machine direction. The frequency of crimp or crimp leg formation will vary with the need for permanence and resistance to decollation of the manifold assembly.
Effectively, therefore, it is desirable to have from about four to eight crimps composed of a plurality of registered crimps or crimp legs 75 defined in at least one of the lateral or longitudinal margins of each of the business forms produced according to the invention. It has also been found particularly efficacious to have a plurality (preferably about three to six, and most desirably for most purposes, four) of these crimps (as shown illustratively in FIGS. 5 and 6 hereof) disposed in transverse parallel alignment in the aforesaid margins.
The crimp blades or punches are adapted to coact with the cylindrical recess 76 (shown by the broken line in FIG. 3) in the female die ring 78, and strike or punch a crimp leg 75 in each of the sheets of the assembly 62; the resulting plurality of crimps 75 being formed in registry with each other and integral with the sheet in which each is formed at one end and depressed from this point or origin through the apertures caused by their formation so that their free distal margins are directed into the path of travel of said assembly through the collating device at a point below the plane of the assembly 62 and at an angle or slant of less than 90°. No matter where the crimps or tabs are placed on the assembled sheets, they are, in accordance with the invention, disposed in a significantly preferred embodiment, in a forwardly directed slant or angle as thus described.
The crimping unit or module 70 is positioned upon the collating machine at a point between the pinfeed cylinders 52 and 54 so that all save one of the record sheets 24 are integrated into the assembly 62 when the assembly leaves the crimping module and passes to the adhesive applicator or glue device 80.
It will be apparent that to provide a plurality of parallel crimps or legs, as shown in FIG. 5, a plurality of blade elements or dies 74 must be mounted on the crimp holder ring 72 shown in side elevation, for example, in FIG. 3. Accordingly, a frontal view of the crimp module 70 would show, in context with the manifold assembly of FIGS. 5 and 6, four or more blade elements 74 evenly spaced in parallel alignment about the periphery of the crimp holder ring 72 and a corresponding number of cylindrical recesses or a continuous cylindrical recess 76 in the female die element 78.
The glue device 80, and its mode of operation are best described by reference to FIGS. 2 and 4, in conjunction with FIG. 1, of the drawing. Again, this element 80 may assume a variety of forms and modifications, but that shown in the drawing represents a preferred embodiment within the contemplation of the present invention. The unit is particularly adapted to use of hot-melt adhesives, although other adhesives including so-called cold glues or adhesives and pressure-sensitive glues and adhesives, are also employed in the practice of the invention and conventional means for applying these latter adhesives, well-known to those skilled in the art to which this invention pertains can be employed in the practice of the invention. Hot helt adhesives are generally and significantly preferred in the practice herein defined because of their brief setting times permitting operation of the process at high speeds.
In the embodiment shown, however, the glue applicator 80 is composed of a heated hot-melt glue supply unit 92 from which adhesive is supplied from the rope of solid adhesive 94, to the dispensing element 96 which is operated by the press release button 98 to renew the supply of adhesive 100 in the adhesive bath or reservoir 102 as it becomes depleted. Where the adhesive is a cold glue or pressure sensitive adhesive in the form of chips or liquid it is delivered to the dispenser conveniently through a tube or hose element.
Positioned in the glue bath or reservoir 102 and fixedly engaged about the axle 104 rotatably mounted to the lateral sides of the reservoir 102 is the glue wheel 106. Both the reservoir 102 and wheel 106 are heated to a temperature sufficient to melt and maintain the hot melt adhesive, where employed, in a molten or liquid state. Standard hot melt adhesives are maintained in the molten state at a temperature within the range of 300° F. to 450° F. It is convenient to make the side walls of the reservoir 102 transparent so that the adhesive level is known at all times without the use of special monitoring equipment and adhesive can be renewed before the adhesive level goes below the level of the glue wheel 106. The horizontally disposed axle 104 may be relocated vertically, that is, raised or lowered, as seen fit, and adjustable means (not shown) for such engagement are provided in the reservoir side walls. The glue wheel extends above the upper surface of the bath and, in operation, rotates in the machine direction. The thickness of the coat of glue present on the exposed upper surface of the wheel as it rotates is metered by the application blade 109 controlled by element 110. The height of the glue wheel is such that glue will be deposited on the surface formed by the plurality of distal margins or tips of the crimp legs without substantially extending this coverage to the adjacent surfaces thereof, and, at the same time, the wheel is so disposed that it will not itself contact the crimps and disrupt the registry of the several tabs or their angle or articulation with the assembly 62. This is essential so that the next step, in the procedure according to the invention, can proceed and the fastening process be successfully concluded.
As shown in FIGS. 1, 2 and 4, there is provided additionally, but optionally, between the crimping module 70 and the adhesive applicator 80, a finger or guide 107, which impinges upon each newly formed crimp causing it to be bent resiliently in a direction opposite to that of the flow of the web in the apparatus, for the purpose of assuring that the crimp will continue to sustain its downwardly disposed alignment and proper contact of the distal margins or tips thereof with the adhesive or glue wheel 106. Also provided desirable are a series of planar support guides 108 positioned before and after the adhesive applicator 80 to prevent undue bowing and flutter or dipping the assembly 62 over the adhesive wheel 106; thus reducing the possibility of contact between the assembly 62 and wheel 106. The supports or guides 108 are longitudinally disposed shafts of restricted width occurring laterally and internally of, or external to, the longitudinal path defined by the passage of the crimps 75 to and from the glue wheel 106. The crimping blades 70 are thus positioned at a distance from the lateral margin of the assembly 62 different from that of the guides 108.
After the glue is applied to the distal transverse margins of the crimps causing the crimp legs, in continuing registry, to adhere at their free ends to one another, the crimp legs so integrated, are moved with the assembly from which they are derived over the pinfeed guide cylinder 56 and into contact with the inner surface of the last underlying ply or sheet 24a which joins the assembly 62 at the pinfeed cylinder 56. The latter cylinder 56 is so positioned that it not only presses the exterior ply 24a into contact with the glue tips of the legs 75, but presses the crimp legs back toward and substantially into the assembly without, however, breaking the contact of the tabs with the inner surface of the exterior underlying ply 24a.
The finished and interlocked assembly 64 is then passed through the wholly conventional transverse web-perforating upper and lower blade-bearing cylinders 132 and 134 which effect a transverse or cross-web perforation of the assembly 64 to provide the continuous assembly of finished forms 66, the foregoing perforations coinciding with the upper and lower margins of the preprinted forms originally dispensed into collated assembly from the rolls 22 and 32.
The manifold assembly of forms 66 is then passed, in the embodiment of the drawing, about the pinfeed cylinder 136, or band (not shown) or other configuration, to the folding mechanism represented schematically by the rolls 140 and 142, where the forms 66 are arranged in zig-zag stacks for compact and efficient handling and storage.
As shown in FIGS. 5 to 7 a continuous manifold assembly 66, resulting from the practice described hereinabove, includes the crimp legs 75 bearing a cured adhesive on the transverse portions of their distal or terminal edges or tips at the point of contact thereof with the underlying exterior ply or sheet 24a and disposed, preferably, or at least conveniently, in the lateral margin of the continuous assembly and between the conventional stub punched aligner and pinfeed holes 25 used to align the forms 66 about the pinfeed cylinder of the collating machine and of the various business machines including calculators, mini-computers, printers, typewriters, teletype machines, or other printing apparatus utilizing continuous forms and the like with which the forms of the assembly are used. Also shown in FIG. 5 are the optionally included standard stub perforations 27, disposed longitidinally and interior to the foregoing pinfeed holes, and the transverse perforations 150 imposed on the assembly by the cylinders 132 and 134 and providing for severance of the continuous assembly 64 into unit manifolds 66 of, illustratively, preprinted business forms, as described elsewhere herein and, in the absence of such severance, for zig-zag folding of the continuous assembly. The mode of attachment of the crimp legs to the inner surface of the underlying exterior ply or sheet 24a (which, as is evident from the description afforded hereinabove and the drawing, is not crimped) is shown particularly in FIGS. 6 and 7. While the manifold assembly of the drawing shows seven record and transfer sheets superimposed on one another, it will be apparent that the apparatus and process of the invention is operative in the interlocking of as little as two or three sheets or webs and without narrowly critical limitation of the upper end of the range. The assemblies formed in accordance with conventional practice, however, will contain not less normally than two sheets or webs and not more than about twenty such sheets, and preferably about 3 to 8 thereof. The practice herein described is capable of utilization with or without interleaved transfer sheets or strips. If desired, record sheets may, therefore, be substituted on the arbors 30 for collation on the pinfeed cylinders of the collation apparatus. The length of the individual crimp legs is not narrowly critical so long as they are not so long as to droop or sag or so short that all or a portion of the free terminal margins of a particular crimp fails to protrude below the plane of the assembly 62. A suitable crimp length normally is within the range of 0.05 inch to 0.1 inch, and preferably about 0.0625 inch.
In the event that transfer sheets are not interleaved in the manifold assembly, a conventional multiple sheet assembly can be substituted wherein each record sheet carries a coating comprising a pressure-transferable image-forming material on one of its surfaces; normally, the under surface of each succeeding sheet of the assembly. The inventional also contemplates the use of commonly and commercially available mated chemical carbonless paper wherein the contiguous surfaces of adjacent sheets contain a chemical coating which produces an image on impact.
It will be evident that the crimps 75 can assume a variety of configurations. The simplest, and normally the most advantageous, is a rectangular crimp or leg in which the free or distal margin is a straight edge. A free U-shaped leg or crimp leg end is, by way of illustration, also useful, however. In the former case, with the rectangular crimp of the drawing, a more permanent bond is secured. In the latter instance, employing a crimp leg in which the free edge is curvilinear, only a limited segment of the distal margin will receive adhesive, and, consequently, the degree of adhesion to the underlying sheet 24a of the joined tabs will be minimal.
In accordance with the invention, the individual sheets or plies of each unit assembly 66 can be removed in series from the manifold without disturbing materially the interconnection of the remaining plies thereof so long as removal is commenced with the exterior ply 24 opposite to that 24a to which the crimp legs 75 are attached; and, for example, is the upper or lower ply.
It will be evident, too, that the terms and expressions which have been employed herein are used as terms of description and not of limitation. There is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, and it is recognized that various modifications are possible within the scope of the invention claimed.
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This invention relates to a flexibly and permanently interlocked manifold assembly of superimposed sheets or webs, and the method and apparatus for producing this assembly, wherein the superimposed sheets of the assembly are fastened by a stress-relieving means composed of crimps formed in one exterior sheet of said assembly and any intermediate sheets thereof; the crimps being formed in registry and the terminal margins thereof having an adhesive coated thereon and attached to the interior surface of the opposing exterior sheet of the said assembly.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hypodermic needles. More particularly, the invention relates to microneedles and fabrication methods thereof.
2. Description of the Related Art
Transdermal drug delivery represents a novel drug delivery route with little damage or pain. Such a drug delivery method has overcome the shortcomings in oral route that the drugs may be degraded in the gastrointestinal tract or be eliminated through the liver. Hence it has now been widely recognized as one of the most promising techniques with numerous commercial applications. The outer layer of skin (stratum corneum) is the most important barrier that prevents the drugs entering into the body. How to break through the stratum corneum painlessly and effectively is the key technique in transdermal drug delivery. Among the transdermal drug delivery techniques, hollow microneedle arrays have now been widely recognized as one of the most promising techniques. It can deliver drugs by painlessly piercing through the stratum corneum without reaching the dermis layer. Compared with methods of ion-implantation and electroporation, the holes throughout the stratum corneum generated by microneedles are much bigger and can delivery macromolecules, super-molecules, or even the particles into the body. Therefore, the fabrication methods for microneedles remain a hotspot research area in recent years. In the early stage, the fabricated microneedles are solid ones and can let the drugs diffuse into the body by generating holes in the skin. Recently, hollow microneedles are proposed for their advantages of the combination of microneedles and drug delivery. The drugs can be delivered into the skin through the tunnels existing in the hollow microneedles, which can greatly improve the efficiency of drug delivery and instantly control the drug species as well as their dosages painlessly and conveniently. However, the fabrications of hollow microneedle arrays mainly relied on the microfabrication techniques of a modified-LIGA process, a combination of deep reactive ion etching (RIE) and isotropic etching techniques, femtosecond laser two photon polymerization, deep x-ray lithography (DXRL) process, photo lithography, inductively coupled plasma (ICP) etcher, focused ion beam (FIB)-assisted technology, etc. In these cases, achieving commercial mass production of hollow microneedle arrays have been hindered greatly mainly by the inherent high cost and low throughput of the existing fabrication methods. Usually, the cost originated from microfabrication processes can be shared by many replicas to ensure the overall low cost. But this case was no longer effective for fabrication of hollow microneedle arrays using the current methods, because the mold had to be sacrificed during the fabrication processes and each mold can be used for only one time. Moreover, the hollow microneedles can be used for only one time to avoid cross infection and contamination. Up to now, it still remains a great challenge to fabricate hollow microneedle arrays efficiently and cost-effectively by commercially mass production, which greatly restricts their applications.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a hollow microneedles and fabrication method thereof that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a simple method for fabricating hollow microneedles.
Additional features and advantages of the invention will be set forth in the descriptions that follow and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
The fabrication method mainly includes processes of (1) coating an elongated template made of a first material with a second material to form a cover; (2) removing a tip of the cover and the template to form an opening in the cover; and (3) removing the template, whereby the cover with the opening forms a hollow microneedle.
The fabrication methods have the following advantages: it can mass produce hollow microneedles; it involves no complicated and expensive equipments or techniques; the quality of the resulted needles is very high; the investment on both fabrication equipments and materials is very low.
The above advantages may enable the fabrication method preponderant among all of the present hollow microneedles fabrication methods.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(A) to 1(D) schematically illustrate a hollow microneedle fabrication process according to an embodiment of the present invention.
FIG. 2 is a scanning electron microscope (SEM) image of a hollow microneedle array fabricated using a method according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the invention will be described more fully hereinafter referencing to the accompanying schematic drawings. Before the present invention is described, it is to be understood that, 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. In the drawings, the thickness of layers and regions are exaggerated for clarity.
FIGS. 1(A) to 1(D) schematically illustrate a hollow microneedles fabrication process according to an embodiment of the present invention. As illustrated, the process includes three steps. Step (1): coating templates of a first material with a second material using techniques including but not limited to painting, spin-coating, sputtering, pulling, electroless plating, electroplating, physical vapor deposition, chemical vapor deposition, sol-gel, or their combinations. Step (2): The tips of the resulting structures are partly removed by methods including but not limited to cutting, shearing, polishing, etching, reactive ion etching, focused ion beam irradiation, lithography, laser irradiation, or their combinations. Step (3): The original templates of the first material are removed by methods including but not limited to sintering, dissolving, melting, etching, or their combinations. The fabrication process is described in more detail below.
FIG. 1(A) is a partial cut-away view illustrating the template needles 10 before Step 1 (the coating step). In Step 1, a surface coating process is used to cover the needles 10 on their surfaces of needle tips 10 A, the surfaces of needle sides 10 B, and the substrate 11 on their top surface 11 A. The coating methods, not listed all here, may be selected from methods of painting, spin-coating, sputtering, pulling, electroless plating, electroplating, physical vapor deposition, chemical vapor deposition, sol-gel, or their combinations. The shape of the template needles 10 is generally elongated, and may be cones, columns, or other more complicated shapes. The material of the template needles may be inorganic materials, or organic materials, or metals, or their combinations. The materials of the needles 10 and the substrate 11 may be the same. The coating material may be inorganic materials, or organic materials, or metals, or their combinations, but it is different from the material of the template needles 10 . Although the term “material” is used in this disclosure in its singular form, it should be understood that the material of the template and the material of the coating can be mixtures of materials or composite materials. The result of the coating step is schematically shown in FIG. 1(B) . The coating material forms needle covers 12 with tips 12 A, sidewall 12 B, and base 12 C. The covering thicknesses of the coating material as indicated in FIG. 1(B) can be adjusted in a range of approximately 20 nm to 500 μm.
In Step 2, the tips 12 A of the needle covers 12 and tips 10 A of the template needles 10 are removed. The removal method may be selected from cutting, shearing, polishing, etching, reactive ion etching, focused ion beam irradiation, lithography, laser irradiation, or their combinations, but not list all here. As schematically shown in FIG. 1(C) , the material coating the surfaces of template needles 10 and the substrate 11 A forms nanostructures with through holes filled with template needles 10 C. In this process, openings 12 D of the needle covers 12 are generated. The sizes of the openings 12 D can be adjusted by the height of the tips 12 A and 10 A that are removed.
Then, in Step 3, the template 10 and substrate 11 are removed to form hollow microneedles 12 . The removal methods may be selected from sintering, dissolving, melting, etching, or their combinations, but they are not all listed here. After this process, as shown in FIG. 1(D) , the hollow needles 12 are formed, each hollow needle including an opening 12 D and a side wall 12 B. The hollow needle array also includes abase 12 C joining the hollow needles.
Accordingly, the hollow microneedles fabrication method enables fabrication of hollow microneedle arrays with very high quality in an extremely cheap and efficient way. It can use microfabrication-free techniques, materials of metals and/or polymers, as described above, which has great flexibilities and be suitable for both lab and industry mass production of hollow microneedles.
FIG. 2 is a scanning electron microscope (SEM) image of a hollow needle array fabricated using a preferred embodiment of the present invention. The resulting nickel hollow microneedles have a height of about 300 μm, a wall thickness of about 10 μm, and an opening diameter of about 20 μm.
A number of specific examples of the microneedle fabrication process are described below.
EXAMPLE 1
A layer of copper with thickness of about 50 μm is electroplated on the surface of poly(methyl methacrylate) (PMMA) microneedles array of 500 μm in diameter for a single needle, then the tips of the needles are removed by about 100 μm in length by cutting. Finally, the PMMA is removed by immersing in trichloromethane for about 2 hours, which results in a copper hollow microneedles array.
EXAMPLE 2
A layer of gold with thickness of about 20 nm is sputtered on the surface of silica microneedles array of 3 μm in diameter for a single needle, then the tips of the needles are removed by about 50 nm in length by etching. Finally, the silica is removed by immersing in hydrofluoric acid for about 60 min, which results in a gold hollow microneedles array.
EXAMPLE 3
A layer of polystyrene with thickness of about 500 μm are directly coated on the surface of iron microneedles array of 2 mm in diameter for a single needle, then the tips of the needles are removed by about 1 mm in length by cutting. Finally, the iron is removed by immersing in hydrochloric acid for about 1 min, which results in a polystyrene hollow microneedles array.
EXAMPLE 4
A layer of nickel with thickness of about 10 μm is electroplated on the surface of poly(methyl methacrylate) (PMMA) microneedles array of 100 μm in diameter for a single needle, then the tips of the needles are removed by about 50 μm in length by polishing. Finally, the PMMA is removed by sintering at 400° C. for about 1 hour, which results in a nickel hollow microneedles array.
EXAMPLE 5
A layer of PZT ceramic with thickness of about 50 μm is sputtered on the surface of poly(methyl methacrylate) (PMMA) microneedles array of 500 μm in diameter for a single needle, then the tips of the needles are removed by about 100 μm in length by polishing. Finally, the PMMA is removed by immersing in trichloromethane for about 2 hours, which results in a ceramic hollow microneedles array.
EXAMPLE 6
A layer of gold with thickness of about 1 μm is electroless plated on the surface of silicon microneedles array of 10 μm in diameter for a single needle, then the tips of the needles are removed by about 10 μm in length by polishing. Finally, the silicon is removed by immersing in KOH solution for about 2 hours, which results in a gold hollow microneedles array.
EXAMPLE 7
A layer of poly(methyl methacrylate) (PMMA) with thickness of about 10 μm is electroless plated on the surface of silica microneedles array of 200 μm in diameter for a single needle, then the tips of the needles are removed by about 50 μm in length by cutting. Finally, the silica is removed by immersing in HF solution for about 2 hours, which results in a PMMA hollow microneedles array.
EXAMPLE 8
A layer of silica with thickness of about 10 μm is sol-gel coated on the surface of polystyrene (PS) microneedles array of 50 μm in diameter for a single needle, then the tips of the needles are removed by about 20 μm in length by polishing. Finally, the PS is removed by sintering at 400° C. for about 1 hour, which results in a silica hollow microneedles array.
EXAMPLE 9
A layer of silver with thickness of about 100 nm is electroless plated on the surface of poly(methyl methacrylate) (PMMA) microneedles array of 3 μm in diameter for a single needle, then holes are generated on the tips of the needles by laser drilling. Finally, the PMMA is removed by immersing in trichloromethane for about 1 hour, which results in a silver hollow microneedles array.
EXAMPLE 10
A layer of nickel with thickness of about 10 μm is electroplated on the surface of polystyrene (PS) microneedles array of 300 μm in diameter for a single needle, then holes are generated on the tips of the needles with focused ion beam. Finally, the PS is removed by sintering at 400° C. for about 1 hour, which results in a nickel hollow microneedles array.
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 purposes of limitation. It will be apparent to those skilled in the art that various modification and variations can be made in the hollow microneedles fabrication processes of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations that come within the scope of the appended claims and their equivalents.
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A novel method suitable for commercially mass production of hollow microneedle with high quality for delivery of drugs across or into biological tissue is provided. It typically includes the following processes: (1) coating an elongated template of a first material with a second material to form a cover; (2) removing tips of the template and cover to form an opening in the cover; and (3) removing the template of the first material to obtain hollow microneedles of the second material. This simple, efficient and cost-effective fabrication method can mass produce hollow microneedle arrays involving no complicated and expensive equipments or techniques, which can be used in commercial fabrication of hollow needles for delivering drugs or genes across or into skin or other tissue barriers with advantages of minimal damage, painless, long-term and continuous usages.
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FIELD OF THE INVENTION
The present invention relates to a device which can be attached to an all terrain vehicle (“ATV”) and used for clearing away loose granular material, such as snow, sand, earth, and crushed stones.
BACKGROUND OF THE INVENTION
All terrain vehicles are popularly used by consumers as recreational vehicles. However, given their ability to manoeuvre on a variety of terrains, ATVs have the potential to be adapted for practical applications such as the removal of snow. Accordingly, there is consumer demand for an ATV attachment which enables the ATV to be used for clearing snow and other loose granular material, such as sand, earth and crushed stones.
It is desirable that the attachment be easily installed and removed, so that the vehicle does not carry any unnecessary weight when the attachment is not in use. However, the devices found in the prior art are relatively cumbersome to install and remove, or have limited applications. Typically, the attachment points for these devices are situated on the underside of the ATV, so that they are not readily accessible to the user. U.S. Pat. No. 3,688,847 teaches a frame assembly which requires the removal of the front wheels of the vehicle in order to initially install the attachment piece for hooking up the frame assembly. U.S. Pat. No. 4,615,130 teaches a frame assembly suitable only for ATV's having a trailer—type hitch on the rear—end of the vehicle. Accordingly, there is a need for an assembly which can be quickly and easily attached and detached from ATV's.
In certain situations it may be desirable to change the angle of the blade on the attachment, for example, when clearing snow adjacent to a wall or fence. However, the prior art suffers from the disadvantage that it can be relatively cumbersome to adjust the angle of the blade. For example, U.S. Pat. No. 4,615,130 teaches the use of retractable pins as a means for locking the blade at a desired angle. However, the removal and insertion of pins requires a certain degree of manual dexterity and maybe difficult to accomplish under cold-weather conditions, when the driver of the ATV is likely to be wearing gloves. Accordingly, there is a need for a device equipped with means for quickly and conveniently adjusting the angle of the blade.
In certain situations, it may also be desirable to raise the blade, for example when travelling to a destination which needs to be cleared. Accordingly, it is desirable to have an attachment that can be easily raised and lowered by the driver while seated on the MV.
Finally, the prior an does not teach a blade with a detachable liner, which would allow the liner to be inexpensively replaced if it becomes damaged, and which would also allow the liner to be inexpensively colour coordinated with the customer's ATV.
SUMMARY OF THE INVENTION
The disadvantages of the prior at are obviated and mitigated by the present invention which provides an attachment for use in shoveling snow and other loose granular material, which can be quickly and easily attached and detached from an ATV; which enables the operator of the MV to easily and quickly adjust the blade to a desired angle; and easily raise or lower the blade of the ATV while seated on the ATV.
In a preferred embodiment, the snow blade has a coloured liner detachably secured to the blade frame, which may be colour coordinated with the body of the ATV.
In a preferred embodiment, the invention provides an apparatus which may be attached to an all terrain vehicle for use in clearing loose granular material; said apparatus comprising a frame assembly adapted to fit beneath the all terrain vehicle in a spaced apart relationship thereto, and to be releasably connected to the outer sides of the all terrain vehicle by a mounting means; blade means for use in clearing loose granular material; said blade means attached to the frame assembly at the front-end of the all terrain vehicle; angle adjustment means for adjusting the angle of the blade means relative to the longitudinal axis of the all terrain vehicle; and vertical adjustment means for raising and lowering said blade means and said frame assembly.
A further embodiment provides a kit comprising a frame assembly adapted to fit beneath the all terrain vehicle in a spaced apart relationship thereto, and to be releasably connected to the outer sides of the all, terrain vehicle by a mounting means; blade means for use in clearing loose granular material; said blade means attached to the frame assembly at the front-end of the all terrain vehicle; angle adjustment means for adjusting the angle of the blade means relative to the longitudinal axis of the all terrain vehicle; and vertical adjustment means for raising and lowering said blade means and said frame assembly.
Additionally, the invention provides an attachment means for releasably securing a frame assembly and blade means to an all terrain vehicles comprising angle adjustment means for adjusting the angle of the blade means relative to the longitudinal axis of the all terrain vehicle; and vertical adjustment means for raising and lowering said blade means and said frame assembly.
An advantage of the present invention is that the attachment points for the frame assembly are easily accessible on the outer sides of the ATV, and therefore the frame assembly can be attached and detached quickly and easily.
Preferably, the vertical adjustment means comprises a dual-handed lever which enables the operator to easily adjust the angle of the blade from either side of the ATV. Because the angle of the blade is adjusted using a simple lifting and turning motion, it is possible to adjust the angle of the blade even while wearing gloves.
A further advantage of this invention is that the driver can easily raise or lower the blade and frame assembly while seated on the ATV, through the use of an over-centering mechanism which enables the blade to stay locked in the up position without the use of latch pins or extra brackets.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention will be obtained by considering the detailed description below, with reference to the following drawings of embodiments of the present invention in which:
FIG. 1 is a side view showing an ATV incorporating the present invention
FIG. 2 is a perspective view of the lift attachment apparatus of the present invention, shown in combination with a blade assembly
FIG. 3 is a top elevated view of the lift attachment apparatus of the present invention, shown in combination with a blade assembly
FIG. 4 is a side perspective view of the lift attachment apparatus of the present invention
FIG. 4A is a side exploded view of the lift attachment apparatus of the present invention
FIG. 5 is a perspective view of the locking means of the lift attachment apparatus
FIG. 5A is an exploded view of the locking means of the lift attachment apparatus
FIG. 6 shows an exploded view of a blade assembly
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, the lift attachment apparatus of the present invention, generally designated as 2 , is shown mounted to an all terrain vehicle (ATV) 4 , and a blade assembly 6 .
Referring to FIGS. 2 and 3, lift attachment apparatus 2 comprises a frame assembly 10 , a locking device 18 and over centering lift handle assembly 30 .
Frame assembly 10 is of substantially A-shaped design, consisting of diverging arms 12 , 13 that are connected by cross members 14 , 15 for reinforcement. The posterior end of the frame assembly 10 is defined by attachment means such as lug 16 disposed at one end of each of arms 12 , 13 . The frame assembly may accordingly be conveniently mounted to the frame of ATV 4 , as shown by FIG. 1 .
Locking device 18 is mounted to the anterior end of frame assembly 10 . As more particularly shown in FIG. 4A, locking device 18 comprises a base plate 19 , and frame member 20 which may be secured to blade assembly 6 by means by of a pivot bolt 21 or other similar securement means. Lock pin assembly 22 comprises dual lock handle 24 which is operatively connected to latch lever means 26 by means of lugs 28 and pivot bolts 29 , and to lock spring 27 .
Frame member 20 is secured to blade assembly 6 by means of bolts or other mechanically equivalent attachment means and is preferably pivotally connected to base plate 19 at attachment point 25 . Spring means 23 acts to bias the blade assembly 6 as against the frame member 20 .
Over center lift handle assembly means 30 comprises handle member 32 which is pivotally connected to base bracket 34 , connecting link 40 , lever 36 and over center pivot arm 38 . Lock spring 41 is secured to pivot arm 38 and to support member 37 . Pivot arm 38 is rotatable along vertical axis A, and may be a first, second, or third class lever. Pivot arm 38 is attached to a lift cable 42 . Lift cable 42 runs along the longitudinal axis of the frame assembly 10 and is received by pulley 44 which is operatively connected to locking device 18 . The free end of lift cable 42 is fitted with attachment means 46 that enables the cable to be secured to the front bumper, or other suitable attachment point on the ATV.
Referring to FIG. 6, blade assembly 6 includes a blade frame 62 which may optionally be fitted with a replaceable blade liner 64 . Blade liner 64 may be detachably secured to blade assembly by means of bolts 66 or similar connection means. Blade frame 62 is rotatably connected to the anterior end of the frame assembly 10 , as described above. The detachable liner enables a damaged liner to be inexpensively replaced. It also enables a dealer to stock fewer blade frames, while providing the consumer with a variety of colour options for the liner. Optionally, a blade guard 67 may be incorporated within the blade assembly.
As will be understood by those skilled in the art, the blade assembly 6 may define a single direction, tapered speed blade, or a bidirectional, conventional blade. All conventional blades and blade frames adapted for use for an all terrain vehicle or similar device are within the scope of the present invention.
The orientation of the locking device 18 relative to the frame assembly 20 means that the blade assembly 6 may be attached to the all terrain vehicle, and the relative angle of the blade may be adjusted, from either side of the all terrain vehicle.
The present invention defines an over centering lift system with significant mechanical advantage that enables the operator of the ATV to easily and conveniently raise and lower the blade assembly without undue manipulation. By pulling back on the handle 32 , the driver can quickly and easily raise the blade assembly 6 . When handle 32 is pulled toward the back of the ATV, the handle lever 36 is pulled toward the front of the ATV which causes the pivot arm 38 to pivot about its axis A, by means of connecting link 40 thereby tightening the lift cable 42 which pulls up on the pulley 44 . This motion is translated to frame member 19 and causes blade assembly 6 to move lo vertically, relative to the ground (“up position”). Once the lift cable 42 has passed over the axis A of the pivot arm 38 , the weight of the blade assembly 6 would tend to cause the pivot arm 38 to continue pivoting about its axis A thereby urging blade assembly 36 to a downward position. However, a pivot am stop 34 is situated so as to block further movement of the pivot arm 38 . This over-centering mechanism holds blade assembly 36 in an up position without the use of pins and extra brackets. The frame assembly 10 and blade assembly 36 remain in the up position by virtue of the over-centering mechanism, described above, until the driver returns the handle 32 to an upright position.
When the handle 32 is in an upright position, the pivot arm 38 is oriented approximately 90 degrees to the longitudinal axis of the ATV, the lift cable 42 is relatively slack and the blade assembly is in a down position, i.e. substantially tangential to the ground surface.
The action of lock spring 41 (attached between the base of the handle 32 and the end of the pivot arm 38 that is attached to the support member 37 ) reduces the manual effort required to lift the blade assembly and ensures that pivot arm 38 achieves a positive lock in the up or down position, thereby preventing blade assembly 6 from dropping to the ground as the ATV travels over rough terrain.
The angle of the blade assembly 6 relative to the ground surface may be adjusted by pulling up on either side of the dual-handed lock handle 24 to release the latch lever 26 , then rotating the frame member 20 about the blade angle pivot attachment point 25 until the blade assembly 6 is at a desired angle relative to the longitudinal axis of the ATV whereupon the latch lever is realigned with a suitable notch 29 on the frame member 20 , and then releasing the dual-handed lock handle 24 so that the latch lever 26 matingly engages with the desired notch. Return spring 27 urges the latch lever 26 against the notch 27 , and thereby serves to lock the blade assembly 6 into the desired angular orientation, relative the longitudinal axis of the frame assembly 10 .
Optionally, the relative mechanical advantage of the over centering lift system may be adjusted by altering the point at which cable 42 is connected to pivot am 38 . This may be accomplished by the provision of one or more additional connection points That may take the form of apertures, eyelets or other similar structures that may be used to secure cable 42 to pivot arm 38 .
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An attachment for an all terrain vehicle (ATV) which enables the ATV to be used for clearing away snow and other loose granular material, such as sand, earth, and crushed stones. The apparatus includes a blade with a detachable liner, and a frame which fits beneath the ATV and is releasably connected to the outer sides of the ATV by a mounting device. The angle of the blade may be adjusted using a dual-handed lever. The blade may be raised and lowered by the driver while seated at the ATV using a handle which actuates a lever and a cable and pulley apparatus.
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REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of co-pending patent application Ser. No. 13/211,451, filed Aug. 17, 2011, entitled “ORIENTATION DEVICE AND METHOD”. The aforementioned application is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The field of this disclosure relates to methods and systems for maintaining visual orientation relative to a point of interest and to a rangefinding GPS system for implementing such methods advantageously and strategically during wilderness maneuvers.
[0004] 2. Description of Related Art
[0005] Navigating to a position of interest after having lost visual contact with your destination has long been a problem. While maps and compasses are well-known and very old technology, following a compass on a cross-country course once the way becomes obstructed by trees, fences, etc., requires a great deal of skill and practice.
[0006] For example, if you find yourself in an unfamiliar wilderness setting and must walk to some (previously) visually acquired distant point, it is quite easy to lose your way, even for experienced outdoorsmen. Unavoidably, as you move, the surroundings change and direct visual contact with your destination is obstructed, as well as original landmarks and other visual points of reference. Before long, you can no longer see the point of interest (POI) to which you plan to travel, and begin to lose most or all visually guiding mechanisms, becoming increasingly disoriented to your path. If unable to regain your bearings, you must walk back to the original vantage point and re-scout the surroundings, costing much time and effort. There are countless scenarios, particularly for military, hunters, biologists, and other outdoor enthusiasts, for whom this type of disorientation frequently occurs, to the great disadvantage of their objective.
[0007] It is possible to use a position-measuring and navigation device such as a Global Positioning System (GPS) receiver to determine where you are when you start navigation, and it is possible to set in a destination point in the GPS if you know the destination by its geographical coordinates (latitude/longitude) or some identifying information such as a name or address (assuming the GPS has such names or addresses in a database). Some devices allow entering the location of a destination by specifying a horizontal offset from a known location—for example, aviation GPS units commonly allow specifying a point as “8 miles on a bearing of 135° from the Ithaca airport” or the like. However, these methods are not of much use in navigating from a known start point to a visual POI, as it is not possible in prior-art navigation systems to set in a destination visually by pointing at something and specifying, “I wish to go there.”
[0008] Determining the bearing and distance to a visual POI has been done by traditional surveying techniques. For example, tripod mounted surveying instruments such as transits and inclinometers could be used to measure bearing and elevation angle. Cross-bearings could be taken from two known locations, and calculations done to triangulate a POI. However, the weight and bulk of such devices make them unsuitable for assisting outdoorsmen who require minimal weight and bulk specifications of their equipment—otherwise their goals are compromised, if not made impossible—and even knowing that your POI is on a bearing of 135° horizontally (or magnetic) and 10° up would not help much once you left your starting point.
[0009] Rangefinding binoculars exist, such as those manufactured by Zeiss, Bushnell or Leupold. These use lasers to determine range to a point and, in some cases, inclination. They are very expensive, and are marketed to hunters so that they can correct their rifles for distance. Further, knowing the range and inclination from your starting point to the POI does not help much with navigation once you leave the starting point and lose sight of the destination in the woods.
[0010] Ballistic algorithms are also seen in a more advanced version of this technology, which calculate a ballistic trajectory rather than only a distance, both of which are displayed in the device's optoelectronic viewfinder. U.S. Pat. No. 7,690,145 “Ballistic Ranging Methods And Systems For Inclined Shooting” describes a method for shooting a projectile weapon by determining the inclination of a line of sight from a vantage point to a target and a line-of-sight range to the target, then predicting a trajectory parameter at the line-of-sight range, for a preselected projectile.
[0011] While a combination of prior art technology could be used to precisely locate a POI—at a minimum, this would require a range finding binocular, a handheld GPS, a mobile calculating device, and a compass with aiming device, along with a great deal of complex mathematics and knowledge on the part of the user. Once done, the process, if it is to achieve a high level of accuracy, is imprecise, impractical, extremely time consuming, and involves multiple devices which must be interchanged, and possibly unpacked and repacked in the user's gear.
[0012] Relevant U.S. patents to the field include the following:
[0013] U.S. Pat. No. 5,825,480 “Observing Apparatus”, superimposes topographic maps in a visual display which obstructs the vision of the user. The method requires topographic information to determine and display a POI. In areas or situations where said topographic information is scarce or inaccurate, the method fails in desired accuracy.
[0014] U.S. Pat. No. 6,233,094 “Telescope Utilizing Global Positioning System (GPS)”, calculates a vector between two devices and does not extrapolate POI coordinates. An external device must physically travel to the spot and record its coordinates before the device may be functional. This invention can only orient a user to a location first provided to it from an outside source.
[0015] U.S. Pat. No. 7,107,179 “Passive Target Data Acquisition Method And System” transmits targeting information to remote command centers and weapons systems.
[0016] U.S. Pat. No. 7,271,954 “Binoculars With An Integrated Laser Rangefinder” is directed primarily to the mechanical details of combining binoculars with a laser rangefinder. The '954 patent mentions including “further electronic measuring devices” such as a GPS, inclinometer, altimeter or compass in the binocular battery compartment, but does not teach or suggest using such devices in combination with the laser rangefinder to provide land navigation to a POI.
[0017] U.S. Pat. No. 7,643,054 “Directed Guidance Of Viewing Devices”, is intended for use in something like a guided tour, where a multitude of devices are synced to known locations. This system requires preprogrammed and known points in order to operate, and its lack of improvisational capabilities make it unsuitable for a wilderness setting.
[0018] U.S. Pat. No. 7,908,083 “System And Method For Recording A Note With Location Information Derived From Rangefinding And/Or Observer Position”, can be used in the field to determine the location of a distant point and record its coordinates along with user inputted “notes” of information to later be pulled from the device and analyzed on a computer. This invention can display the distance and bearing to the desired POI at the point where it is first used. However it requires that a direct line of sight be established in order to do so. After the user has moved and potentially maneuvered with respect to a recorded POI, if the user no longer has direct visual contact with the POI, the user cannot use this method to orient themselves.
SUMMARY OF THE INVENTION
[0019] The invention streamlines the process of navigation from a starting point to a visual point of interest by combining the necessary items into a single device incorporating an optical finder such as binoculars which incorporates an optical display into the optical device's viewfinder, a rangefinder, GPS, compass, altimeter, inclinometer, microprocessor and memory. The device performs three functions: 1) acquires the POI's coordinates relative to the user by visual indication of the POI by the user; 2) reproduces an updated POI vector on demand; and 3) displays the POI vector information in the device viewfinder. All three functions happen seamlessly and instantaneously with the use of only one compact hand held device.
[0020] The invention also provides a method of personal orientation in a wilderness or unfamiliar setting using a device determining the coordinates of current user position in three-dimensional space, or Origination Point (OP), and then acquiring the coordinates of a Point of Interest (POI). Information to determine global coordinates include longitude, latitude and elevation—which the device discovers directly with embodied instruments or extrapolates using inclination, distance, and compass bearing to the POI. OP and POI coordinates are acquired either by the device itself or can be inputted by supplementary devices. While maneuvering, the user calculates updated vectors to a POI from various positions and maintains relative position orientation with respect to one or multiple POIs.
[0021] The POI vector information is displayed in the device viewfinder, providing visual orientation for improved knowledge of relative position and enabling accurate landmark acquisition for successfully traversing a landscape to the destination position. The method may be embodied in a handheld laser rangefinding binocular including memory for storing acquired position data and a computer processor for performing calculations.
BRIEF DESCRIPTION OF THE DRAWING
[0022] FIGS. 1 a - 1 f collectively form a flowchart of the method of the invention.
[0023] FIGS. 2 a and 2 b show the method output in the horizontal plane, more specifically in the event the POI vector lies within the field of view theta degrees to the left of center.
[0024] FIGS. 3 a and 3 b show the method output in the vertical plane, more specifically in the event the POI vector lies within the field of view theta degrees upward from center.
[0025] FIG. 4 shows an example of a user and a POI.
[0026] FIG. 5 a shows a user moving with respect to a POI.
[0027] FIGS. 5 b - 5 f show first person user perspectives through the device while moving with respect to a POI.
[0028] FIG. 6 shows a diagram of the POI vector and the mathematical figures and variables required to extrapolate the ellipsoidal distance to the POI; the POI's elevation; and then the POI coordinates.
[0029] FIG. 7 shows a diagram of the POI vector and the mathematical figures and variables required to extrapolate the real distance to the POI and the inclination to the POI.
[0030] FIG. 8 shows an overhead diagram showing how the POI vector bearing information is considered in the method for orientation purposes.
[0031] FIG. 9 shows a view through a viewfinder of horizontal POI vector bearing information as it is considered for coordinating use of the pointing indicators
[0032] FIG. 10 shows a side view diagram of how the POI vector inclination information is considered in the method for orientation purposes.
[0033] FIG. 11 shows a view through a viewfinder of the POI vector incline information is considered for coordinating use of pointing indicators.
[0034] FIG. 12 shows the different indicators with which the user interacts with the system and environment through the viewfinder.
[0035] FIG. 13 a shows a block diagram of the device instruments and architecture.
[0036] FIG. 13 b shows a three-dimensional view of the preferred form of the device.
[0037] FIG. 13 c shows a three-dimensional view of one of the many alternatively embodied devices that can implement the invented system & method.
DETAILED DESCRIPTION OF THE INVENTION
[0038] The invention electronically records global coordinates of a Point of Interest relative to the point of origin, and allowing this data to be stored and referenced throughout a journey. On a dark or moonless night or through a valley of fog, with this system, a user is able to walk directly from the OP to the point of interest without losing their bearing. Such ability is valuable both for convenience and safety purposes.
[0039] Furthermore, the ability to record an exact location without first traversing to the position and recording its coordinates is equally valuable, among the many practical applications of these systems and methods.
[0040] The concept at work here is to greatly and seamlessly improve user visual orientation. The circumstances by which this invention was conceived brought this point to attention. Outdoorsmen of many kinds heavily rely on optics such as binoculars to make observations creating a tactical plan based on the lay of the land to achieve their goal. As users move, they continuously use optics to check progress and re-orient themselves visually, often with the aid of a handheld GPS device. Current GPS configurations require users to look first down at the GPS in their hand to gather a heading, and then must look up and project, by user judgment alone, the bearing vector against the background environment. Then, when the user has estimated how the bearing vector lays against the landscape, the user must resume optics to further scout the vector and incorporate this new information into their observation and strategy. The process is imprecise, impractical, and involves multiple devices which must be interchanged, and possibly unpacked and repacked in the user's gear. The invention disclosed streamlines the above process and items into a single device, and eliminates the human error involved in guessing how a GPS derived bearing would extend against a distant mountainside for landmark designation.
[0041] FIG. 5 a illustrates an overhead view of the movement of a user 57 with respect to a POI 55 , in this case a rock. In phase 1 the user 57 , in position 58 , has a visual line of sight 60 to the POI 55 . He visually acquires the POI 55 and begins the method of the invention, to be described in detail below. He proceeds along path 62 toward position 59 . As he approached position 59 , in Phase 2, the user 57 loses orientation with respect to the POI 55 —trees 56 block the line of sight 61 to the POI 55 as well as other crucial landmarks. The user 57 continues implementation of the method to construct an updated POI vector, and regains visual orientation.
[0042] FIG. 12 shows the outputs of the method as the user sees them displayed in the device viewfinder 140 (or 161 in FIG. 13 a ). The reticule 141 represents the center of the viewing axis and is used to aim the device for POI designation. Indicators 142 - 146 alert the user as to their orientation in the horizontal plane. Similarly, indicators 147 - 151 point the user toward visual orientation in the vertical plane.
[0043] For each POI, only one indicator from each the horizontal and vertical indicator groups is activated at any given time, and transition between indicators reflects the users progress toward visual orientation by following previous indicators. The distance, or magnitude of the POI vector, 152 is shown in the upper right of the display. Also shown is the elevation differential 153 , the difference between the user's elevation and that of the POI. A multitude of alternative information 154 may also be displayed alongside that for basic visual orientation.
[0044] FIG. 13 a is a block diagram exemplifying one potential architecture of the system. In this example all instruments, modules and components 160 - 175 are encased together into one device housing 177 ; although in alternative forms, the invented system may be successfully implemented by a myriad of separate devices working together, so long as they are able to communicate as required and carry out the system functions. The electronic elements of the device are connected via the circuitry 176 depicted by the network of arrowed lines showing the flow of power and information.
[0045] The optical instrument 160 could be implemented as binoculars, monocular, telescope, goggles or glasses. The optics of the optical instrument define the viewing vector along which light from an image passes through the instrument to the user.
[0046] Integrated into the optical instrument 160 is the viewfinder display 161 , an optoelectronic module which is clear if not stimulated, or can be activated to show readouts on in the user's field of view associated with the viewing vector while looking through the binocular.
[0047] A computer processor 170 coordinates the actions of the system via an operating system and application code as well as processes information. The flow of commands and information from the other modules and devices will preferably pass through a plurality of inputs and at least one output of the processor 170 . Computer memory module 171 records and catalogues information that is either been created by the method or that the method will require in its processes.
[0048] A compass 162 gathers azimuth (bearing) data with regard to the current orientation of the viewing vector, that is applied in extrapolating the POI vector. The azimuth data is provided at an output.
[0049] An inclinometer 163 is calibrated to zero where the viewing vector is level relative to gravity, and measures incline or decline of the device as it deviates from the leveled state. The data representing the inclination is provided at an output.
[0050] A rangefinder 164 having a laser for measuring distance to a target is arranged to point along the optical axis. The rangefinder is calibrated and coordinated with the viewfinder display 161 such that a reticule in the center of the viewfinder indicates the precise pointing of the laser, so that it is aimed by looking through the device. Thus, the user can indicate a target with the reticle and the rangefinder 164 will measure the distance to the target and provide data indicating the distance for further processing.
[0051] A GPS receiver module 165 provides global coordinates in longitude and latitude (lat/lon) of the current position of the receiver (i.e. of the device and the user). The lat/lon coordinates are provided at an output.
[0052] An altimeter 166 may be included to measure the user's elevation above sea level. This data may be used in critical analytical steps to ensure the accuracy and precision of the method. Altitude data would be provided at an output.
[0053] Optionally, a transceiver module 167 enables the system to both receive and send information, this might include POI information, waypoint coordinates, or other data collected for or during the method implementation. The ability to share information remotely is desirable in a wilderness setting. The transceiver 167 would have an input and output for data flow.
[0054] A battery 168 supplies electrical energy to the system so that the circuit components may operate, although a secondary option involves plugging into a stationary power source through an AC/DC converter (adapter) 169 , which protects the circuitry and also recharges the battery 168 .
[0055] User interface 172 allows the user to activate the device and command the system throughout the method steps—external buttons or voice recognition controls may be employed. The user interface would have inputs and outputs coupled to the processor 170 as needed.
[0056] Digital clock 173 may be used to time stamp recorded data, so that a specific time is allocated to each POI acquired, or way point achieved, etc. This assists in cataloguing and organization of data for analysis. The digital clock may be built into the processor 170 , or a separate module having an output coupled to an input of the processor 170 for passing time stamp data to the processor 170 . Alternatively, time data can be derived from the GPS signal and provided to the processor by the GPS receiver 165 .
[0057] External display 174 might be employed to assist with user interfacing and management of data inputted and outputted from the method.
[0058] Optionally, additional instruments 175 can be built into the device, possibly including environmental condition sensors such as humidity, barometric pressure or temperature gauges, or other instruments that may provide useful information during data collection and navigation via the invented method.
[0059] FIG. 13 b shows a three-dimensional depiction of one possible system device embodiment. Pictured is a basic pair of binoculars, the optical instrument 160 , with two optical tubes 180 containing the necessary lenses and prisms 182 for an optical instrument, as well as eyepieces 184 where the user looks into the viewfinder.
[0060] Most of the electronic components are arranged apart from the optics in separate compartments 181 —this might include compass 162 , inclinometer 163 , rangefinder 164 , GPS module 165 , altimeter 166 , transceiver 167 , battery 168 , AC/DC converter 169 , computer processor 170 , memory modules 171 , additional instruments 175 , as well as interconnecting circuitry 176 . Components of the right hand optical tub are exposed to show the Viewfinder Display 183 ( 161 ) nestled within the optical components so that it will be seen while looking through the device. Buttons 185 allow the user to interface 172 with the device.
[0061] FIG. 13 c shows a three-dimensional depiction of an alternative embodiment. In this case, the optical instrument 160 comprises a rangefinding monocular 190 containing all of the necessary optical components. Just as in FIG. 13 b , the electronic components are segregated from the ocular tube into surrounding compartmental spaces 193 , the viewfinder display is integrated into the monocular (not illustrated, see 183 ), and external buttons 192 allow the user to interface with the device. The distinguishing feature of this alternative embodiment is the addition of an external display 191 ( 174 ), possibly touch screen, which allows for increased versatility and interfacing options such as ease of POI and waypoint management.
[0062] One practical example of this involves the use of device shown in FIG. 13 c for orientation purposes on a golf course. The inclusion of an external display allows the golfer to have at his or her disposal both an overhead map view of the hole in question on which POI's can be selected and analyzed as well as a heads up viewfinder perspective of the same information. The POI may be selected, modified, and viewed via either of the two options, as the two share information directly. In a forward orientation process, the golfer can acquire a POI with the rangefinder by looking through the device, and then observe on the external display where that point lies with respect to the target hole for further analysis. If this analysis reveals that adjustments to the POI via the external display will further optimize the golfer's strategy, then he or she can make the necessary adjustments before observing the new POI vector through the viewfinder for confirmation. Alternatively, in a reverse process, the golfer can select a point on the externally displayed map as a waypoint target enroute to the hole, and then observe along the vector to the waypoint POI through the viewfinder. Should a sand trap or other obstruction, not disclosed on the map, be found to lie in this path that the shot must follow, the golfer can then adjust by selecting an alternative POI through the viewfinder that will skirt the obstacle, before re-visiting the external display for further analysis of the effects of this adjustment on the future strategic plan.
[0063] FIG. 4 shows a schematic view of the real-world setup which will be diagrammed in the context of the method below in FIGS. 6-12 . The user 51 is at the Origination Point OP, looking up hill 54 at an Alpine shepherd's but 50 to which he would like to hike, and which forms the Point of Interest POI. The hut 50 is at a higher elevation 53 relative to the OP. The direct line distance 52 from the OP to the POI leads upward at a slope.
[0064] FIGS. 1 a - 1 f collectively form a flowchart of the method of the invention. The method starts in FIG. 1 a , then flows by connectors A or B to FIG. 1 b , from where subroutines (shown in FIGS. 1 d - f ) depart and then return to the same page—then the method flows through connector D back to FIG. 1 b to complete the loop. Where appropriate, the steps will refer to the diagrams and displays of FIGS. 6-12 .
[0065] The steps in the method are as follows:
1 . The method starts. 2 . Are the coordinates of the POI known?
3 . If the coordinates of the POI are known, skip ahead (connector A) to step 15 ( FIG. 1 b ). Known coordinates include those acquired first-hand on previous excursions, or received wirelessly from another source. 4 . If not, pass on to step 5 . 63 . The first step in the method is to designate a POI from an established OP. This overall step is indicated by the dashed line 63 in FIG. 1 a , and a diagram of the elements found can be seen in FIG. 6 . 5 . Acquire the Origination Point (OP)—The GPS receiver 165 in the device is activated and acquires the global coordinates of the OP, or user position when POI is designated. The OP coordinates (Φ 1 , λ 1 ) are recorded in the computer memory module 171 . 6 . Acquire the OP elevation—An altimeter 166 can be read to acquire user elevation (Z 1 ) above sea level, or the information can be derived from the GPS 165 . User elevation (Z 1 ) is recorded in the computer memory module 171 . 7 . Acquire the distance between the OP and POI—The rangefinder 164 is activated and acquires the distance (L 1 ) from the OP to the POI (or magnitude of the POI vector). The distance (L 1 ) is recorded in the computer memory module 171 . 8 . Measure the Viewed Incline—the inclinometer 163 is activated and acquires the inclination bearing above or below the horizon. The incline (θ 1 ) is recorded in the computer memory module 171 . 9 . Acquire the compass bearing—the embodied compass 162 is activated and acquires the horizontal bearing, or forward azimuth, from the OP to the POI. The forward azimuth (α 1 ) is recorded in the computer memory module. 10 . With the above information simultaneously captured and stored, the next step in the method is to determine the location of the POI. The computer processor 170 via software programs accesses the computer memory 171 to withdraw the needed information and performs the following:
11 . Approximate the ellipsoidal distance to POI (See FIG. 6 )—using simple trigonometry of a right triangle having hypotenuse L 1 , and inclination angle θ 1 , the adjacent side (s) represents an approximation of the arc length across earth's curvature between the OP and POI global coordinates.
[0000] Evaluate: cos(θ 1 )= s/L 1 →s=L 1 *cos(θ 1 )
Approximated ellipsoidal distance (s) is recorded in the computer memory 171 . 12 . Derive approximate POI elevation—An approximation of POI elevation (Z 2 ) can be determined by adding the difference in OP & POI elevation (ΔZ 1 ) to known OP elevation (Z 1 ).
[0000] Evaluate: cos(θ 1 )=|Δ Z 1 |/L 1 →|ΔZ 1 |=L 1 *cos(θ 1 )
[0000]
Z
2
=ΔZ
1
+Z
1
Approximated POI elevation (Z 2 ) is recorded in the computer memory 171 .
13 . Extrapolate the POI coordinates—ellipsoidal distance (s), compass bearing or forward azimuth (α 1 ), and OP coordinates (φ 1 , λ 1 ) are input into appropriate geodesic formulae such as Vincenty's Direct Method. Given an initial point (Φ 1 , λ 1 ) and initial azimuth, α 1 , and a distance, s, along the geodesic the Vincenty direct method finds the end point (Φ 2 , λ 2 ) and azimuth, α 2 by the steps of:
Start by calculating the following:
[0000]
tan
U
1
=
(
1
-
f
)
tan
φ
1
σ
1
=
arc
tan
(
tan
U
1
cos
α
1
)
sin
α
=
cos
U
1
sin
α
1
;
cos
2
α
=
(
1
-
sin
α
)
(
1
+
sin
α
)
u
2
=
cos
2
α
a
2
-
b
2
b
2
A
=
1
+
u
2
16384
{
4096
+
u
2
[
-
768
+
u
2
(
320
-
175
u
2
)
]
}
B
=
u
2
1024
{
256
+
u
2
[
-
128
+
u
2
(
74
-
47
u
2
)
]
}
Then, using an initial value
[0000]
σ
=
s
bA
,
iterate the following equations until there is no significant change in σ:
[0000]
2
σ
m
=
2
σ
1
+
σ
Δσ
=
B
sin
σ
{
cos
(
2
σ
m
)
+
1
4
B
[
cos
σ
(
-
1
+
2
cos
2
(
2
σ
m
)
)
-
1
6
B
cos
(
2
σ
m
)
(
-
3
+
4
sin
2
σ
)
(
-
3
+
4
cos
2
(
2
σ
m
)
)
]
}
σ
=
s
bA
+
Δσ
Once σ is obtained to sufficient accuracy evaluate:
[0000]
φ
2
=
arctan
(
sin
U
1
cos
σ
+
cos
U
1
sin
σcos
α
1
(
1
-
f
)
sin
2
α
+
(
sin
U
1
sin
σ
-
cos
U
1
cos
σ
cos
α
1
)
2
)
λ
=
arc
tan
(
sin
σ
sin
α
1
cos
U
1
cos
σ
-
sin
U
1
sin
σ
cos
α
1
)
C
=
f
16
cos
2
α
[
4
+
f
(
4
-
3
cos
2
α
)
]
L
=
λ
-
(
1
-
C
)
f
sin
α
{
σ
+
C
sin
σ
[
cos
(
2
σ
m
)
+
C
cos
σ
(
-
1
+
2
cos
2
(
2
σ
m
)
)
]
}
α
2
=
arctan
(
sin
α
-
sin
U
1
sin
σ
+
cos
U
1
cos
σ
cos
α
1
)
Where:
[0000]
A is length of major axis of the ellipsoid (radius at equator) (6,378,137.0 m in WGS-84);
B is length of minor axis of the ellipsoid (radius at poles) (6,356,752.314 m in WGS-84);
f=(a−b)/a is the flattening of the ellipsoid (1/298.257223563 in WGS-84);
Φ 1 , Φ 2 are the latitude of the points;
U 1 =arctan [(1−f) tan Φ 1 ] and U 2 =arctan [(1−f) tan Φ 2 ] are the reduced latitude;
λ 1 , λ 2 are the longitude of the points;
L=λ 2 −λ 1 is the difference in longitude;
α 1 , α 2 are the forward and reverse azimuths;
α is the azimuth at the equator (i.e., the great circle/ellipse, or “arc path”, the points are on); and s is the ellipsoidal distance between the two points.
Outputs of forward process [POI coordinates (Φ 2 , λ 2 ) & reverse azimuth (α 2 )] are recorded and stored in the computer memory 171 .
14 . With the information stored from the steps above, the user now leaves his initial OP 58 and proceeds along his path 62 , at some point losing visual contact and thus orientation with respect to the POI.
85 . Once the user has decided it is time to re-orient to the surroundings, it is indicated that the new position has been reached, from where the subsequent method steps are performed.
64 . The second step in the method is to extrapolate the vector to the POI from the new user position. This overall step is indicated by the dashed box 64 in FIG. 1 b , and diagrams of the elements found can be seen in FIGS. 7 , 8 , and 10 . Although these steps are diagramed sequentially, they may be performed in out of the illustrated order. In creating an updated user→POI vector, the steps occur in parallel software processes. User position with respect to the POI is extrapolated thusly by again activating the device which accesses stored computer memory 171 and performs the following functions via software and the computer processor 170 :
15 . Discover the new user position—the GPS module 165 is activated to find the user global coordinates. The updated user position (Φ 3 , λ 3 ) is recorded in the computer memory 171 .
16 . Determine the new user elevation—the altimeter 166 is activated to determine user elevation above sea level, or the new elevation is retrieved from the GPS. Elevation (Z 3 ) is stored in the computer memory 171 .
17 . Extrapolate updated ellipsoidal distance (s) from OP to POI—the POI coordinates (Φ 2 , λ 2 ) and user position (Φ 3 , λ 3 ), are accessed in the computer memory 171 via the operating system and computer processor 170 .
[0102] Software in the processor 170 uses these two data points (Φ 2 , λ 2 ) and (Φ 3 , λ 3 ) as inputs to find the arc length between the current user position and the POI. One successful method can be by the following calculation (Vincenty's Inverse Method), although a multitude of mathematical techniques can be employed to approximate the ellipsoidal distance:
Given the coordinates of the two points (Φ 2 , λ 2 ) and (Φ 3 , λ 3 ), the inverse method finds updated azimuths α 1 , α 2 and the new ellipsoidal distance s. Evaluate: Calculate U 1 , U 2 and L, and set initial value of λ=L. Then iteratively evaluate the following equations until λ converges:
[0000]
sin
σ
=
(
cos
U
2
sin
λ
)
2
+
(
cos
U
1
sin
U
2
-
sin
U
1
cos
U
2
cos
λ
)
2
cos
σ
=
sin
U
1
sin
U
2
+
cos
U
1
cos
U
2
cos
λ
σ
=
arctan
sin
σ
cos
σ
sin
α
=
cos
U
1
cos
U
2
sin
λ
sin
σ
cos
2
α
=
1
-
sin
2
α
cos
(
2
σ
m
)
=
cos
σ
-
2
sin
U
1
sin
U
2
cos
2
α
C
=
f
16
cos
2
α
[
4
+
f
(
4
-
3
cos
2
α
)
]
λ
=
L
+
(
1
-
C
)
f
sin
α
{
σ
+
C
sin
σ
[
cos
(
2
σ
m
)
+
C
cos
σ
(
-
1
+
2
cos
2
(
2
σ
m
)
)
]
}
When λ has converged to the desired degree of accuracy (10 −12 corresponds to approximately 0.06 mm), evaluate the following:
[0000]
u
2
=
cos
2
α
a
2
-
b
2
b
2
A
=
1
+
u
2
16384
{
4096
+
u
2
[
-
768
+
u
2
(
320
-
175
u
2
)
]
}
B
=
u
2
1024
{
256
+
u
2
[
-
128
+
u
2
(
74
-
47
u
2
)
]
}
Δσ
=
B
sin
σ
{
cos
(
2
σ
m
)
+
1
4
B
[
cos
σ
(
-
1
+
2
cos
2
(
2
σ
m
)
)
-
1
6
B
cos
(
2
σ
m
)
(
-
3
+
4
sin
2
σ
)
(
-
3
+
4
cos
2
(
2
σ
m
)
)
]
}
s
=
bA
(
σ
-
Δσ
)
Where:
[0000]
Φ 2 , Φ 3 is the latitude of the points;
U 1 =arctan [(1−f) tan Φ 1 ] and U 2 =arctan [(1−f) tan Φ 2 ] are the reduced latitude;
λ 2 , λ 3 are the longitude of the points
L=λ 3 −λ 2 is the difference in longitude
α 1 , α 2 are forward and reverse azimuths;
α is azimuth at the equator (i.e., the great circle/ellipse, or “arc path”, the points are on); and
s is the ellipsoidal distance between the two points.
The resulting output is an approximation of the ellipsoidal distance s. This output is stored in the computer memory module 171 .
18 . Calculate aximuth (bearing) of the POI vector. Using solved variables from the previous step 17 to evaluate:
[0000]
α
1
=
arc
tan
(
cos
U
2
sin
λ
cos
U
1
sin
U
2
-
sin
U
1
cos
U
2
cos
λ
)
α
2
=
arctan
(
cos
U
1
sin
λ
-
sin
U
1
cos
U
2
+
cos
U
1
sin
U
2
cos
λ
)
Resulting outputs are azimuths α 1 (forward) , α 2 (reverse) . These outputs are stored in the computer memory module 171 .
19 . Approximate the user to POI elevation change: ΔZ 2 =Z 3 −Z 2 ; POI elevation change (ΔZ 2 ) is stored in the computer memory module 171 .
20 . Approximate the incline attributed to the POI vector (See FIG. 7 )—Creating a solvable triangle with sides s, |ΔZ 2 |, L 3 :
[0000] tan(θ 3 )=Δ Z 2 /s→θ 3 =tan −1 (Δ Z 2 /s )
Note: θ 3 can be positive or negative to reflect incline vs. decline. Inclination of the POI vector (θ 3 ) is recorded in the computer memory 171 . 21 . Approximate the real distance (magnitude of the vector) to the POI (See FIG. 7 ):
[0000] Distance→ L 3 =( s 2 +|ΔZ 2 | 2 ) 1/2
Magnitude of POI vector (L 3 ) is stored in the computer memory module 171 . 65 . With the completion of steps 15 through 21 , the attributes of the POI vector have been calculated. The subsequent steps make the updated POI vector, whose attributes were acquired in steps 18 - 21 , available for visual orientation purposes of the user. Each attribute of the POI vector (bearing, inclination, and distance), as well as elevation difference, is retrieved from memory 171 by software via the processor 170 as needed. The third, fourth, and fifth steps of the method are indicated by subroutines 84 , 85 , 86 that are described in the dashed boxes 67 in FIG. 1 d , 70 in FIG. 1 e , and 83 in FIG. 1 f respectively. All of these steps— 67 , 70 , & 83 —are performed simultaneously in practice, but will be described below as individual processes in numerical order. 84 . Bearing orientation, the process of calibrating user gaze in the horizontal plane, is described in this subroutine that flows to FIG. 1 d before returning. 66 . Start of the third step of the method ( FIG. 1 d )—the computer and user interaction process of becoming oriented in the horizontal plane (collectively step 67 ) is initiated upon completion of the POI vector extrapolation process 64 . 22 . Compare POI bearing (α 1 ) to viewed bearing (Ω):
Before proceeding to the comparison, it is useful to reference FIG. 8 —an overhead or perpendicular view of the horizontal plane.
The viewed bearing (Ω) which is the bearing at which the center of the device reticule is aimed at any given time, continually updates as the device pans the horizontal plane 100 . The 360 degree plane rotates with Ω which, as far as this program is concerned, maintains the value of 0 or 360 degrees. In this scenario, the degrees 0-360 occur clockwise from Ω. This program is coded, to make available for visual comparison, the viewed bearing (Ω) versus the bearing to the POI (α 1 ). The two are synchronized against each other in the optoelectronic display 110 and its range of view (R), the number of degrees out of 360 in the horizontal plane that are included within the viewfinder at any given time. This is a constant. 0.5R is the number of degrees between the edge of the field of view and the center of the field of view which is in line of the vertical crosshair 111 of the reticule 141 .
Azimuth (α 1 ) is retrieved from the memory module 171 and inputted to a software process as described (See FIG. 9 for optoelectronic display reference):
Note—For horizontal plane orientation, the only items that are visible to the user are indicators 142 - 146 when activated, and the reticule 141 . The horizontal plane reference line 100 , and markers 108 ; 109 in FIG. 9 are purely for illustrative purposes.
Only one indicator of horizontal orientation may be activated at once—which one is determined by the relative position of α 1 versus Ω (see FIG. 9 ). Referenced indicators are shown in FIG. 12 . For 180°>α 1 >0:
142 . If 0°+0.5R<α 1 , then the right arrow indicator is activated, showing that α 1 is to the right outside the field of view. 143 . If 0°+0.5R>α 1 , then the indicator representing 0+α 1 degrees 109 to the right of Ω is activated
For 360°>α 1 >180°:
144 . If 360°−0.5R>α 1 , then the left arrow indicator is activated, showing that α 1 is to the left outside the field of view. 145 . If 360°−0.5R<α 1 , then the indicator representing 360°−α 1 degrees 108 to the left of Ω is activated.
For α 1 =Ω then:
146 . The optoelectronic indicator at Ω (0 or 360 degrees) is activated, showing the POI vector as being down the line of sight of the device reticule 141 in the viewfinder 140 .
23 . Display in viewfinder—the resulting indicator to be activated is now displayed in the viewfinder 141 in accordance with references 142 - 146 in FIG. 12 . 24 . (α 1 )=(Ω)?—Now the user is to interpret the indicator as displayed in the viewfinder. Decision:
25 . If α 1 does not equal Ω, proceed to 26
26 . User physically follows the indicators by panning to the left or right. Now steps 22 - 26 are reiterated until α 1 equals Ω.
27 . If α 1 does equal Ω, no more horizontal adjustments are necessary; the user is oriented with respect to the POI in this dimension. Proceed to 68 .
68 . Return—user orientation in the horizontal plane has been achieved, return to FIG. 1 c. 85 . Incline orientation, the process of calibrating user gaze in the vertical plane, is described in this subroutine that flows to FIG. 1 e before returning. 69 . Start of the fourth step of the method ( FIG. 1 e )—the computer and user interaction process of becoming oriented in the vertical plane (collectively step 70 ) is initiated upon completion of the POI vector extrapolation process 64 . 28 . Visual incline orientation along the POI incline (θ 3 ) (See FIG. 10 )—[Note* this step is identical to 22 except in the vertical rather than horizontal plane]. Incline (θ 3 ) is retrieved from the memory module 171 and inputted to a software process as described (See FIG. 11 for optoelectronic reference): The viewed incline (β), the incline at which the center of the device reticule is aimed at any given time, and continually updates as the device pans the vertical plane 120 . The 360 degree plane rotates with β which, as far as this program is concerned, maintains the value of 0 or 360 degrees. In this scenario, the degrees 0-360 occur clockwise (downward) from β. This program is coded, to make available for visual comparison, the viewed incline (β) versus the incline to the POI (θ 3 ). The two are synchronized against each other in the optoelectronic display and its range of view (R 2 ), the number of degrees out of 360 in the vertical plane that are included within the viewfinder at any given time. This is a constant. 0.5R 2 is the number of degrees between the top or bottom of the field of view and the center of the field of view which is level with the horizontal crosshair 122 of the reticule 141 .
Note—In vertical plane orientation, the only items that are visible to the user are indicators 147 - 151 when activated, and the reticule 141 . The vertical plane reference line 120 , and markers 118 ; 119 shown in FIG. 11 are purely for conceptual purposes. Only one indicator of vertical orientation may be activated at once—which one is determined by the relative position of θ 3 versus β. For 180°>θ 3 >0°
147 . If 0°+0.5R 2 <θ 3 , then the downward arrow indicator is activated, showing that θ 3 is downward and outside the field of view. 148 . If 0+0.5R 2 >θ 3 , then the indicator representing 0+θ 3 degrees 119 below β is activated
For 360°>θ 3 >180°
149 . If 360°−0.5R 2 >θ 3 , then the upward arrow indicator is activated, showing that θ 3 is to the upward and outside the field of view. 150 . If 360°−0.5R 2 <θ 3 , then the indicator representing 360°−θ 3 degrees 118 above β is activated.
For θ 3 =β then:
151 . The optoelectronic indicator at β (0 or 360 degrees) is activated, showing the POI vector as being along the incline of the device reticule 141 in the device viewfinder 140 .
29 . Display in viewfinder—the resulting vertical plane indicator to be activated is now displayed in the viewfinder in accordance with references 147 - 151 in FIG. 11 . 30 . θ 3 =β?—Now the user is to interpret the indicator as displayed in the viewfinder. Decision:
31 . If θ 3 does not equal β, proceed to 32
32 . User physically follows the indicators by panning upward or downward as instructed—now steps 28 - 32 are reiterated until θ 3 equals Ω.
33 . If θ 3 equals Ω, no more vertical adjustments are necessary, the user is oriented with respect to the POI in the vertical dimension. Proceed to 81 .
81 . Return—visual orientation in the vertical plane is achieved, return to FIG. 1 c. 86 . The process of calibrating user gaze to distance, elevation difference, and alternate informatica, is described in this subroutine that flows to FIG. 1 f before returning. 82 . Start of the fifth step of the method ( FIG. 1 f )—the computer process of becoming oriented with static information including distance, elevation discrepancy, and alternate information (collectively step 83 ) is initiated upon completion of the POI vector extrapolation process 64 . 34 . Distance visual orientation [the magnitude of the POI vector (L 3 )] (See FIG. 12 )—Distance (L 3 ) is retrieved from computer memory 171 and is displayed 142 in the viewfinder 140 for comprehension by user depth perception. The referenced distance number, 783, is purely illustrative, showing in this example that the POI vector is 783 yards in length. As the user observes along POI vector, L 3 indicates how far in that direction the POI lies. 35 . Elevation discrepancy orientation (See FIG. 12 )—The elevation discrepancy (ΔZ 2 ) is retrieved from the computer memory 171 and displayed 153 in the viewfinder 140 . As the user observes the POI vector, ΔZ 2 indicates how much higher or lower in elevation the POI lies relative to their current position. In this case, for illustration purposes only, ΔZ 2 equals −62, meaning that the POI is 62 feet lower in elevation. This information is useful for strategic maneuvering purposes. 36 . Display alternative information in the viewfinder 140 —a multitude of alternative information may also be displayed 154 . For example temperature, or humidity that are acquired by alternatively embodied instruments 175 may be retrieved from computer memory 171 for display. Additionally, time of day recorded by the digital clock 173 or true bearing acquired by the compass 162 might be shown. Information provided from an external supportive device can also be included. For example, Overland Distance, or the true distance a user will hike to a POI, found by calculating distance along the curvature of a topographical path, can also be displayed 154 as an alternative bit of information. There are multitudes of other information types that can be useful and displayed. 337 . Return—visual orientation for distance, relative elevation, and alternative informatica has been achieved. Return to FIG. 1 c and proceed through connector D to complete the method loop back to step 14 in FIG. 1 b.
[0169] With the completion of the simultaneous 3 rd , 4 th , and 5 th method steps ( 67 , 70 , and 83 respectively) the method has come to an end. The User now looks directly along the POI vector (See FIG. 12 ) where their gaze has been calibrated with the distance 152 , elevation change 153 , azimuth or compass bearing 146 , and inclination 151 to the POI—All of which are displayed simultaneously in the viewfinder 140 and reconcile to the reticule 141 .
[0170] Having walked through the method in full, it is prudent to re-visit the example scenario depicted in FIG. 5 a , this time referencing the user-viewed results of the system and method in its most basic functionality ( FIGS. 5 b - 5 f ).
[0171] In Phase 1 the user 57 located at point 58 notices the large rock 55 and designates the object a POI (see FIG. 5 b for user view). Using the buttons or voice recognition as user interface 172 , the user selects the POI designation function from the electronic menu displayed in the viewfinder.
[0172] Next the user aims the reticule 141 at the rock by viewing along the current POI vector 60 , thus committing the rock's position information to the device's memory 171 (see FIG. 5 c for user view).
[0173] Reassured that the objective POI coordinates will not be lost, the user maneuvers along desired path 62 before reaching point 59 . The user, wishing to re-orient with regard to the rock and traverse towards it, enters Phase 2.
[0174] Looking around he realizes that the landscape has changed, many trees 56 now obstruct his view, and he cannot be certain of a direct path toward his goal. Consequently, the user wishes to construct an updated POI vector.
[0175] For the purpose, the invented system and method are again consulted, this time the POI vector recreation function is selected and the device is re-activated to extrapolate the POI vector (steps 15 - 37 ).
[0176] Now, looking through the device, the user is pointed in the direction of the POI vector (see FIG. 5 d for user view)—by interacting with the indicators, he knows the POI is slightly downward of the current aiming point, but out of view to his right. Guided by the indicators, the user directs his gaze downward and to the right. He now finds that the vertical indicator shows that he is oriented in the vertical plane, however he must continue panning to the right, since the horizontal indicator is still right of center, although now within the view of the device (see FIG. 5 e for user view). The user continues to pan to the right, bringing the horizontal indicator in line with the vertical crosshair of the reticule (see FIG. 5 f for user view).
[0177] Now, although the user cannot see the rock, he is looking directly along the POI vector towards it, and knows the rock lies 783 yards directly ahead and is 62 feet lower in elevation. Although the user cannot see the rock, he now knows where it lies, relative to his current position 59 . By using this knowledge, and reiterating the vector reconstruction as necessary, the user is able to traverse 61 through the confounding maze of trees, until successfully arriving at the destination rock POI 55 .
[0178] FIGS. 2 a and 2 b illustrate how the horizontal outputs of methods outlined in the preceding steps, specifically a bearing (or azimuth) θ 73 assigned to the POI vector, is made useful to the user for visual orientation in the viewfinder 71 ; where, FIG. 2 a is seen through the viewfinder which is embedded in the horizontal plane 75 , and, FIG. 2 b is an overhead perspective, or perpendicular view of the horizontal plane.
[0179] The indicated bearing is measured from the vertical center of the viewfinder 72 , which for illustrative purposes takes on the value of true north, in this depiction. The bearing along the horizon 73 is depicted with a marker 74 against the observed landscape indicating where the POI lies in the horizontal plane.
[0180] FIGS. 3 a and 3 b illustrate how the inclination (vertical plane) output calculated in the vector reconstructing method is utilized in the viewfinder 76 . FIG. 3 a shows an “in plane view” through the viewfinder, while FIG. 3 b illustrates the same concept from a side view, or perpendicular to FIG. 3 a . The angle Θ 79 above or below the horizon 77 is depicted with a marker 80 against the observed landscape indicating the incline to the POI as it lies in the vertical plane 78 .
[0181] Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
GLOSSARY OF TERMS
[0000]
Altimeter: is an instrument used to measure the elevation of an object above a fixed level, in this case, sea level.
Art: refers to the categorical use of the invented system and methods in accordance to the common use of “art” when discussing intellectual property, i.e. “prior art”. In this case the “Art” is that of an outdoorsman, where the invention is used in assistance of the objectives of outdoors enthusiasts such as hunters, hikers, field biologists, Division of Wildlife officers, etc. who frequently rely on familiarity and visually acquired landmarks to traverse a wilderness setting.
Blue-tooth: is an open standard for short-range radio transmission for data synchronization between computers and/or computer-based devices.
Computer Memory: is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor.
Computer Processor: is the logic circuitry that responds to and processes the basic instructions that drive a computer.
GPS Receiver: receives a signal from a constellation of Earth-orbiting satellites. The U.S. military developed and implemented this satellite network as a military navigation system, but it was made available for civilian navigation. GPS provides global coordinates to the receiver at any position on earth.
Inclinometer: is an instrument that measures the angle it is pointing above or below a designated horizon plane.
Optoelectronic Display: operating hardware that converts electrical signals to a user-visible display.
Orientation Device & System (ODS): refers to the invention disclosed in this document, a method and device for remotely identifying and recording a POI's coordinates in three dimensional space and providing relative visual orientation with regard to the POI as the user's current position while maneuvering.
Point of Interest (POI): refers to a point in three dimensional space, desired as a destination, that is recorded and tracked by the ODS.
Three-Axis Tilt Compensating Compass: is an electronic compass which, regardless the angle at which its held, orients itself to know which way is up and which way is north.
|
A method and device for streamlining navigation from a point to a visual point of interest by combining the necessary items into a single device incorporating an optical finder such as binoculars which incorporates an optical display into the viewfinder, a rangefinder, GPS, compass, altimeter, inclinometer, microprocessor and memory. The device performs three functions: 1) acquires the POI's coordinates relative to the user by visual indication of the POI by the user; 2) reproduces an updated POI vector on demand; and 3) displays the POI vector information in the device viewfinder. All three functions happen seamlessly and instantaneously with the use of only one compact hand held device.
| 6
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/009,985, filed Dec. 4, 2013, which it the National Stage of International Application No. PCT/NL2012/050217, filed Apr. 2, 2012, which claims the benefit of Great Britain Application No. GB 1105755.1, filed Apr. 5, 2011, the contents of all of which are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates to a method of forming a substrate for a sports surface of a sports pitch.
[0003] The invention also relates to a substrate obtained with the method according to the invention.
[0004] Furthermore the invention also relates to a sports pitch provided with such subtrate.
BACKGROUND OF THE INVENTION
[0005] Many sports, such as field hockey, tennis, American football etc are currently played on artificial turf (grass) sports pitches, which in general comprising a carrier as well as artificial fibres extending from said carrier. Said carrier is placed on a substrate which forms a stable subsurface base construction for the complete pitch installation.
[0006] Examples of sports that utilise such artificial turf pitch (ATP) constructions are:
[0007] Soccer
[0008] American Football
[0009] Australian Rules Football
[0010] Gaelic Football/Hurling (GAA)
[0011] Rugby Union/League
[0012] Hockey
[0013] Cricket outfields etc
[0014] In addition to sports pitches, the basic methodologies explained above also apply to other smaller areas in which artificial turf maybe used. For example:
[0015] Play grounds
[0016] Landscape/leisure areas
[0017] Cricket wickets
[0018] Bowls rinks
[0019] Tennis courts
[0020] Futsul courts
[0021] Education multiple use areas
[0022] The traditional base construction methodology for artificial turf systems has historically been based around the excavation of the existing sub-base and the subsequent replacement of this sub-base with graded rock and specially designed drainage systems.
[0023] There has been substantial development in construction methodologies and systems that are designed to limit and/or replace the use and design of traditional base construction system. These systems have been primarily designed to reduce the cost and to simplify the work untaken.
[0024] Due to the increasing awareness of human activity on the environment, the issue and practice of recycling has become more popular. In many cases governments are now legislating for the increased practice of recycling end of life and waste materials. This practice is seen at all levels of society and business, from road side recycling of household waste to legal obligations and quotas on businesses to recycle or dispose of waste in an environmentally responsible manner. This has also become a key political issue and the general trend of thinking is to reduce waste, carbon footprint, as well as waste to traditional landfill. National and local governments, plus private contractors have developed large infrastructures in order to divert some materials away from landfill for the purpose of recycling.
[0025] A new industry has developed which has been improving and developing methods of collection, separation and industrial processes that increase the ability to reclaim key materials from waste sources. One of the largest parts of the recycling industry is the recycling of plastics. However, these companies tend to process materials that are easy to convert and have the highest grades and re-sale value.
[0026] The vast majority of waste plastics is mixed (co-mingled) and as such is difficult to identify, sort, separate, clean and recycle and is therefore too expensive to process. In addition, the grades of these materials are very low and therefore have little re-sale value and are therefore regarded as “end of life” plastics.
[0027] Such ‘end of life’ plastic materials are typically in the form of packaging materials, moulded articles, products, profiles, sheet, coatings, fabrics or fibers and are found in general industrial, manufacturing, building and household waste etc. They can broadly be described as:
Plastic granules, beads, pellets, slivers, flakes, chips and noodles derived from recycling plastics. These types of plastics cover all families of polymers defined as plastics, such as, but not limited to the families of Polyolefin, Polyesters, Polyamides, Poly Vinyl Chlorides (PVC's), Polystyrenes and Polyurethanes found in general industrial, manufacturing, land transportation, aerospace, agricultural, horticultural, food and general packaging, building and household waste. Also, sources such as material reclaimed from landfill and material retrieved/harvested from the oceans in the form of flotsam and jetsam. Plastic granules, beads, pellets, slivers, flakes and noodles derived from recycling artificial grass surfaces, domestic and industrial floorings. The types of plastics cover of the families of Polyolefin, Polyesters, Polyamides, PVC's, Polystyrenes and Polyurethanes.
[0030] This material is referred to as “Feedstock” and there are vast quantities of this material available. Feedstock will generally consist of a random mix of plastic types, sizes, densities, colours; in a form of being flexible, rigid, semi rigid, filled or expanded in character or nature and are likely to include thin sheets, film, fibers, etc.
[0031] As such, to be made suitable for use in the formation of the invention the feedstock material must be processed using mechanical methods which result in a granulate with a more consistent size, bulk density and volume. Such processes are known as densification or agglomeration.
[0032] Densification or agglomeration is a process well known in the recycling plastics industry, in which plastics are chopped into fine flakes and then fed into a machine which uses friction to convert them into a semi molten state. The fine flakes join together increasing the mass and density of the material flowing through the machine. The mass of plastics exiting the machine is cooled, chopped, granulated or otherwise comminuted to a predetermined size. The densifying process includes one or more sieving stages whereby granulate which is considered to be outside the predetermined useful range is automatically returned to the infeed of the densifying process. In the vast majority of plastics recycling the aim for the processor is to ensure the plastic material been put into the process is of the same polymer type and the material is totally free from other polymer types and totally clean. As explained previously this requires a great deal of pre-processing to ensure that the final granules are fit for sale to the plastic industry, much of the waste plastic collected is either to dirty, too mixed or be at the end of the ability to re-recycle to be of any commercial value, and is therefore landfilled and burnt.
SUMMARY OF THE INVENTION
[0033] For the purposes of the invention the plastic material (referred to above as Feedstock) used in the agglomeration process can be any type of plastics and the presence of some foreign materials which are non-plastic (e.g. wood, paper, fibres) are not an issue, therefore the amount of pre-processing is reduced and increased quantities of material due for landfill or burning are reused.
[0034] To be considered suitable for use in the formation of the invention, the densified plastic granulate shall be of a size whereby the ratio of the largest dimensional plane of each granule (x) and its perpendicular dimensions (y and z) are at least 30% to 100% of the largest dimensional plane.
[0035] The cornerstone of the invention is to use the Feedstock plastic, which is then agglomerated into granules and then used in the construction of base construction profiles in the applications described in the background section above.
[0036] The basis of the invention is to create a system which provides an option for either an in-situation or a pre-formed module which has the properties of base point loading, compression strength, in-built porosity and controlled/managed drainage, plus in-built shock absorption.
[0037] The system is designed to limit the environmental impact and carbon footprint of the base construction element while reducing the financial cost of the project. The system will reduce the amount of spoil removed from site by reducing the required excavation depths (depending on pre-existing geological conditions). Although certain aspects of the traditional base profile will still be required, the amount of rock required to build up the base profile will be significantly reduced. There will still be a requirement for the geo-textile membrane and the non-porous capping layer.
[0038] In order the achieve the desire properties, balanced against the existing geological conditions and the reduction of environmental construction impacts, the invention uses the granules as the aggregate material which in turn is bound together in order to stabilise the structure, resulting in a substrate layer according to the invention.
[0039] The binding materials can be Polyurethane, Bitumen or Polyofin displacements, which are mixed (either hot or cold) with the granules at ratios depending on application and property requirements. Such binders are characterised to impart thermal stability, hydrolytic stability, having no significant change in properties upon being submerged in water or exposed to changing humidity and temperature environments. Thus the desired structural integrity and physical properties remain on standing and when in use.
[0040] The granules are in a loose granule form and depending on the application and properties required the size range of the granules is between 0.5 mm to 20 mm. The ratio or particle range of these sizes is adjusted depending on the properties required. Added to this is the binding material which is added using formulas based on weight of the granules. These ratios range between 8% binder by weights to 30% binder by weight.
[0041] The invention will be made in a porous permeable form by using proportions of granules and binder so that sufficient void or interstitial space remains between the granules. This void space can vary in amount in accordance with the particulate which is used for example between 15% to 60% by volume. Such void space will be an advantage to allow drainage in all directions, vertically and laterally.
[0042] Void space can also be used to provide storage or attenuation of water if is so necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The invention will now be discussed in the detailed figurative description below, wherein:
[0044] FIG. 1 represents the cross-section of a typical, known dynamic base construction profile according to the state of the art;
[0045] FIG. 2 represents the cross-section of a typical, known engineered base construction with shock pad profile;
[0046] FIG. 3 represents the cross-section of another typical, known engineered base construction with in-situation shock pad profile;
[0047] FIG. 4 represents the cross-section of another typical, known engineered base construction with preformed shock pad profile;
[0048] FIG. 5 represents the cross-section of an in-situation sub-grade course construction profile according to the invention;
[0049] FIG. 6 represents the cross-section of a preformed sub-grade course in panel format construction profile according to the invention;
[0050] FIG. 7 represents the cross-section of an in-situation sub-grade course and performance course construction profile according to the invention;
[0051] FIG. 8 represents a cross-section of a pre-formed dual-density performance course plus sub-grade course in panel format construction profile according to the invention;
[0052] FIG. 9 represents the cross-section of an in-situation composite course construction profile according to the invention;
[0053] FIG. 10 represents the cross-section of a preformed Composite course in panel format construction profile according to the invention; and
[0054] FIG. 11 represents the cross-section of an in-situation sub-grade course and performance course construction profile over an existing brown field substrate according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0055] For example FIG. 1 represents the cross-section of a typical, known dynamic base construction profile according to the state of the art:
1 . Turf surface 2 . Loose stone binding 3 . Grade rock sub-base 4 . Non-porous capping layer 5 . Natural soils 6 . Field water drains
[0062] When constructing an ATP according to the state of the art, many projects are referred to as ‘full build’ projects, which are defined as new-build pitches constructed on a virgin site and include the construction of a stable sub-grade, drainage system, porous base, optional shock absorption layer and finally the artificial turf surface.
[0063] The start of the construction process is to remove a pre-determined depth of existing sub-soils 5 . This depth is determined by a geological survey which measures and classifies the conditions on that particular site. These conditions relate to the make up of the existing sub grades, plus local drainage, rainfall and general location factors. From this data the depth of excavation and the profile of the base construction can be designed.
[0064] The depth and therefore the volume of spoil 5 removed can be quite wide-ranging. However an average of 0.5 metres depth of removal is usually performed. It is also assumed that the average sized ATP would be 6000 square metres (m 2 ). As a consequence, the amount of spoil to be removed from a 6000 m 2 pitch construction would be 3000 m 3 . Typically, all spoil is transported to landfill, hence a large cost in transportation, landfill fees and impact on the environment.
[0065] In order to prevent water movement from the sub-soil base into the new base construction, a capping layer of geo-textile 4 and specially graded rock/dust 3 must be installed before the main body of the new base is constructed. Over the top of this capping layer 4 is installed a drainage system 6 , which is designed to remove water permeating down through the upper rock sub-base by means of drainage pipes in the field pattern. These pipes lead the water off the playing area into ring main land drains or similar water drainage control systems. In some cases water is piped into storage facilities and re-circulated back on to the pitch, either as part of the turf system performance or for use as cooling during hot weather.
[0066] The excavated area (with capping layer 4 ) now needs to be in filled with layers of specially graded rock 2 and 3 which will provide a stable, free draining platform on which to install the playing surface 1 . The rock has to be sourced and graded to a particular specification and this rock needs to be transported to site, in filled, levelled and compacted. In some cases the correct rock specification may only be available in certain quarries, which in turns adds to the cost and environmental impact.
[0067] Most standard ATP systems are designed to have either a ‘dynamic’ or ‘engineered’ base construction. However there are some variations which are deemed acceptable in some localised markets around the world.
[0068] Dynamic bases (also known as un-bound bases) are defined as base profiles that have a loose rock construction 2 throughout and are topped with a compacted, rock binding layer. This binder layer consists of fine graded rock dust and is designed to be stable and free draining.
[0069] FIG. 2 represents the cross-section of a typical, known engineered base construction with shock pad profile:
7 . Asphalt wearing course 8 . Asphalt load bearing layer 3 . Graded rock sub-base 4 . Non-porous capping layer 5 . Natural soils 6 . Field water drains
[0076] Although engineered bases (also known as bound bases) still have the loose rock construction 2 as described above with reference to FIG. 1 , instead of being topped with the loose binding layer, they are typically topped with two layers of porous asphalt, indicated with reference numerals 7 and 8 .
[0077] The first layer or levelling/load bearing layer 8 consists of a certain consistent rock grade bound with bitumen laid at an average depth of 25 millimetres (mm). The second layer, known as the wearing course 7 is paved over the first asphalt layer 8 and consists of a finer graded rock bound with bitumen.
[0078] There are strict tolerances required when installing this upper wearing course 7 which ensures the finished surfaces is level and free from ridges, dips and bumps. This critical element requires expensive paving machinery which is operated by highly skilled workers and is a considerable cost in the overall base construction. Furthermore, it is a time consuming process.
[0079] It is a common occurrence for the upper wear layer 7 to be installed outside acceptable tolerances and therefore requires extensive remedial works. These works add un-budgeted cost to the project and impact on the project on time completion mandates.
[0080] Depending on the type of artificial turf system to be installed a shock absorption layer 9 or 10 (see FIGS. 3 and 4 ) maybe required over the completed base construction 7 - 8 - 3 - 4 . There are a very wide range of ‘shock pad’ systems available that generally fall into two main categories:
[0081] In-situation as shown in FIG. 3
[0082] Pre-formed as shown in FIG. 4
[0083] FIG. 3 represents the cross-section of a typical, known engineered base construction with in-situation shock pad profile:
1 . Turf surface 9 . In-situation shock pad 7 . Asphalt wearing course 8 . Asphalt load bearing layer 3 . Graded rock sub-base 4 . Non-porous capping layer 5 . Natural soils 6 . Field water drains
[0092] The in-situation pads 9 of the FIG. 3 embodiment are defined as pads that are installed on-site by a machine directly onto the base construction. The vast majority of in-situation pads are paved directly onto the dynamic or engineered base construction and use a combination of rubber granules mixed with a Polyurethane binder.
[0093] The rubber granules used in such pads are generally sourced from recycled/granulated car and truck tyres and are referred to as Styrene-Butadiene-Rubber (SBR) granules. In some markets a small ratio of pea gravel is mixed with the rubber and again bound with Polyurethane binder. The mixture is laid onto the base construction with a specialised paving machine, which controls the depth and evenness of the shock pad.
[0094] An advantage of this form of installation is that the pad 9 is attached to the base construction 7 - 8 - 3 - 4 and is therefore dimensionally stable both during installation and during the play life of the pitch. There are no seams or joints in this form of pad and therefore limited potential for failure.
[0095] This process requires highly specialised equipment, operated by highly skilled workers. As in the laying of the asphalt wear layer 7 the tolerances required are very strict and often remedial work is required.
[0096] FIG. 4 represents the cross-section of a typical, known engineered base construction with preformed shock pad profile:
1 . Turf surface 10 . Preformed Shock pads 7 . Asphalt wearing course 8 . Asphalt load bearing layer 3 . Graded rock sub-base 4 . Non-porous capping layer 5 . Natural soils 6 . Field water drains
[0105] Pre-formed shock pads 10 are pads that have been manufactured away from the work site by companies who specialise in this area. Although this form of shock pad 10 can also be produced from SBR rubber and Polyurethane binder, other pre-formed systems use a much wider range of materials. These alternative systems comprise many other shock absorbent materials such as open and closed cell foams, felts, three-dimensional random or woven matrices, all of which can be constructed with either virgin of recycled materials.
[0106] As pre-formed products are made in a controlled factory environment the tolerances of thickness, density and performance can be controlled. The system can be made into a variety of formats, but the most common are rolls or panels. These rolls or panels 10 are delivered to the work site and installed onto the base construction by various techniques by the workers who generally install the turf. Little specialised installation equipment is required and the work skill level is reduced. As the products are manufactured under controlled environments the strict tolerances of conformity are easier to meet with limited remedial work required.
[0107] However, the drawbacks for this type of pad tend to be around the added cost of transportation from the manufacturing site to the work site. These pad formats tend to be quite bulky and this in turn limits the how many square metres can be loaded per container or truck.
[0108] In addition, pre-formed pads 10 can suffer from dimensional instability and movement during turf installation and during the playing life of the pitch. There is also a potential for failure in the joints or seams 10 a created during installation. Furthermore, any small undulations in the base/sub-base 7 - 8 - 3 - 4 cannot be ‘masked’ or levelled by the pre-formed layer 10 as they are a constant thickness.
[0109] In general terms pre-formed shock pads 10 ( FIG. 4 ) are a more expensive system when compared to in-situation pads 9 ( FIG. 3 ).
[0110] It is worth noting that the base construction profiles and methodologies described above accounts for approximately 40-50% of the entire cost of the project.
[0111] Due to surface usage demands and the sports/bio-mechanical requirements specified by sports governing bodies, the use of shock pads under artificial turf is becoming more common, especially in the increasing volume markets of contact sports such as Soccer, American Football, Rugby, Australian Rules football and Gaelic Football.
[0112] Most forms of shock pad can be engineered to provide satisfactory performance for the sports/bio-mechanical performance for certain sports but this can often compromise the performance requirements of other sports. Therefore the ability to design a turf system which is a true ‘cross code’, multiple use surfaces is limited.
[0113] For example, a surface which conforms to the highest Soccer performance criteria will not offer the required performance characteristics for a top level Australian Rules football surface.
EXAMPLES
[0114] The follow are examples of possible ratios of granules granule size range and binder content by weight, based against application:
Example 1
[0115] A structure consisting of particle sizes form 0.5 mm to 5 mm and a binder content of 10% by weight of granules will deliver increased properties for bio-mechanical values but decrease the civil engineering values. This kind of ratio suits areas where the underlying geology is stable, either from exist sub-soils/grades or where existing ATP are been renovated, hence the pre-existence of a stone base layer.
[0116] The layer offers a shock absorbent and safety value which still offers the properties of water management and some civil engineering values such as point and spread loading, allow some reduction in base construction depth, depending on the depth of the layer according to the invention.
Example 2
[0117] A structure consisting of particle sizes form 5 mm to 10 mm and a binder content of 15% by weight of granules will deliver good properties for bio-mechanical values and good values for civil engineering values. This kind of ratio suits the vast majority of applications as the required properties are balanced while offer excellent water management properties. The structure allows for a significant reduction in base construction depth, depending on the depth of the layer according to the invention.
Example 3
[0118] A structure consisting of particle sizes from 10 mm to 20 mm and a binder content of 20% by weight of granules will deliver decreased properties for bio-mechanical values but increased the civil engineering values. This kind of application suits areas where the underlying geo-graphical is un-stabile, or the demands of the end use require high civil values for point loading. The layer offers some shock absorbent value which still offers the properties of water management and increased ability for water storage within the layer according to the invention.
[0119] The strength of this structure further reduces the base construction depth depending on the thickness of the layer according to the invention.
[0120] The example listed above represent a Soft, Medium and Hard structures, but the adjustment of the granules granule size spread with the 0.5-20 mm range, plus the ratio of binder content, plus the depth of the layer gives the ability to design and formulate, tailor made solutions in all applications and environments. In some instances the layer according to the invention would benefit from the inclusion of non-plastic materials, such as rubber ganules, recycled glass chippings, stone chipping, lava stones and pea gravel. These inclusion will help assist added values in either sports performance values or civil enginnering values.
[0121] Depending on the playing surface design and requirements the system would either be a single layer of material according to the invention; which would replace the standard ‘dynamic’ base construction profile. This layer is now referred to as the ‘sub-grade course’.
[0122] In the case that the system requires a shock pad then a second layer (herein referred to as the ‘performance course’) would be placed on top of the sub-grade course.
[0123] Some applications may allow a composite single layer which would offer the required values for sub-grade and performance courses.
[0124] The sub-grade course is designed to act as the load bearing and drainage layer and replaces the vast majority of excavation depth and subsequent volume of rock required in standard construction profiles. The thickness of this layer can range from 10 mm to 100 mm depending on the underlying geological conditions. The layer can be composed using granules at granule size ratios which are formulated depending on the performance required, while parameters are influenced by the existing geological and drainage conditions, point loading and stability requirements. The nature of this layer allows the free flow of water both horizontally and vertically, therefore a standard field drainage system is not required.
[0125] If required, base profiling and design could allow water to be held within the sub-grade course. The benefit of this water retention would have a double benefit; firstly to create a mini artificial aquifer, thus allowing water to be retained and re-circulated to water fully-synthetic (water-based) Hockey pitches. Secondly, for pitches with infill systems, to help assist in cooling the playing surface; either by re-circulating water from the mini aquifer onto the playing surface, or through retaining moisture in the infill materials from the sub-grade layer up.
[0126] The two methods of installation of this sub-grade course would be:
1. Direct installation of the sub-grade course (in-situation method as described above) as shown in FIGS. 5 , and 2. Indirect installation of the sub-grade course (pre-formed method as described above) as shown in FIG. 6 .
[0129] FIG. 5 represents the cross-section of an in-situation sub-grade course construction profile:
1 . Turf surface 11 . In situation sub-grade course 4 . Non-porous capping layer 5 . Natural soils
[0134] The materials are mixed together in the pre-determined ratios and a binding agent is added and mixed with the materials. The resulting mixture is paved directly onto the capping layer 4 in the same manner as asphalt, utilising the same machinery. While the skill level required ensuring correct levels and smoothness is still important, it is an existing skill with no new special requirements or training.
[0135] FIG. 6 represents the cross-section of a preformed sub-grade course in panel format construction profile:
1 . Turf surface 11 . Performed sub-grade course in panel format with inter-locking profile. 4 . Non-porous capping layer 5 . Natural soils
[0140] The sub-grade course 11 can be manufactured off-site in panel format and then installed over the capping layer 4 . The materials are mixed together in the pre-determined ratios and a binding agent is added and mixed with the materials. This resulting mixture can be extruded or moulded or formed as a mass and cut sliced or otherwise divided into separate panels, boards or tiles 11 which can have inter-locking faces 11 a - 11 b to allow the panels 11 to be close fitting or locked together during on site installation.
[0141] The benefit of this delivery method is that the consistency of the layer 11 can be controlled under strict manufacturing conditions. The design of the panels 11 also allows quick and easy installation in all weather conditions with no specialised equipment required.
[0142] In a further improvement an additional performance course 12 ( FIGS. 7 and 8 ) can be implemented in the overall construction. The performance course 12 is designed to act as a stable shock absorption layer with added point loading, replacing the wearing asphalt course and the in-situation or pre-formed shock pad. The thickness of this layer 12 can range from 5 mm to 100 mm depending on the shock absorption characteristics required. The layer can be composed of one or more of the materials described above, mixed in various ratios. These ratios are formulated depending on the performance required. The layer 12 is porous and displays the same water control and management characteristics as the sub-grade course described above.
[0143] The two methods of installation of this sub-grade course 12 would be:
1. Direct installation of the performance course onto sub-grade course (in-situation method described above) as shown in FIG. 7 ; 2. Indirect installation of the performance course onto sub-grade course (pre-formed method described above) as shown in FIG. 8 .
[0146] FIG. 7 represents the cross-section of an in-situation sub-grade course and performance course construction profile:
1 . Turf surface 12 . In situation performance course 11 . In situation sub-grade course 4 . Non-porous capping layer 5 . Natural soils
[0152] The materials are mixed together in the pre-determined ratios and a binding agent is added and mixed with the materials. The resulting mixture 12 is paved directly onto the sub-grade course 11 in the same manner as asphalt, utilising the same machinery. The binder in the performance course 12 reacts with the cured binder in the sub-grade course 11 during installation so that both layers 11 and 12 are firmly locked together. While the skill level required ensuring correct levels and smoothness is still important, it is an existing skill with no new special requirements or training.
[0153] FIG. 8 represents a cross-section of a pre-formed dual-density performance course 12 plus sub-grade course 11 in panel format construction profile 20 :
1 . Turf surface 20 . Dual density panel format with inter-locking profile. 4 . Non-porous capping layer 5 . Natural soils
[0158] As with the off-site manufacture of the sub-grade course 11 (described above with reference to FIG. 6 ) the separate panels 11 and 12 can be manufactured as ‘dual density’ panels 20 . The materials for the sub-grade course 11 are still mixed together in the pre-determined ratios and a binding agent is added and mixed with the materials. This resulting mixture is extruded or moulded into panels 11 as before. However, there is a second step in which materials for the performance course 12 is still mixed together in the pre-determined ratios and a binding agent is added and mixed with the materials. These materials are then extruded or moulded on top of the sub-grade course or layer 11 to form two distinct layers within the same panel 20 .
[0159] The panel now has all the properties required of the two courses 11 and 12 . These panels are designed to have inter-locking ‘male’ and ‘female’ profiles 20 a - 20 b. These profiles allow the separate panels 20 to be locked together during on site installation.
[0160] The benefit of this delivery method is that the consistency of the layer 20 can be controlled under strict manufacturing conditions. The design of the panels 20 also allows quick and easy installation in all weather conditions with no specialised equipment required.
[0161] Depending on the geological and sport performance specifications the system can be designed as a composite grade. The composite grade is one layer 13 which offers the performance of both the sub-grade course/layer 11 and performance course/layer 12 . The performance is pre-determined by the selection of materials and the mixing ratios of those materials. This layer 13 can be installed either by the in-situation of pre-formed methods described above. The thickness of this layer can range from 5 mm to 100 mm depending on the characteristics required. The layer 13 is porous and displays the same water control and management characteristics as the other methods described above.
[0162] The two methods of installation of this composite course would be:
1. Direct installation of the composite course (in-situation method described above) as shown in FIG. 9 ; 2. Indirect installation of the composite course (pre-formed method described above) as shown in FIG. 10 .
[0165] FIG. 9 represents the cross-section of an in-situation composite course construction profile:
1 . Turf surface 13 . In-situation composite course 4 . Non-porous capping layer 5 . Natural soils
[0170] The materials are mixed together in the pre-determined ratios and a binding agent is added and mixed with the materials. The resulting mixture 13 is paved directly onto the capping layer 4 in the same manner as asphalt, utilising the same machinery.
[0171] While the skill level required ensuring correct levels and smoothness is still important, it is an existing skill with no new special requirements or training.
[0172] FIG. 10 represents the cross-section of a preformed composite course 13 in panel format construction profile:
1 . Turf surface 13 . Pre-formed composite course in panel format with inter-locking profile. 4 . Non-porous capping layer 5 . Natural soils
[0177] The composite course 13 can be manufactured off-site in the panels 13 ′ and then installed over the capping layer 4 . The materials are mixed together in the pre-determined ratios and a binding agent is added and mixed with the materials. This resulting mixture is extruded or moulded into panels 13 ′ which are designed to have inter-locking ‘male’ and ‘female’ profiles 13 a - 13 b. These profiles allow the panels 13 ′ to be locked together during installation.
[0178] The benefit of this delivery method is that the consistency of the layer 13 can be controlled under strict manufacturing conditions. The design of the panels 13 also allows quick and easy installation in all weather conditions with no specialised equipment required.
[0179] In another embodiment shown in FIG. 11 it is now possible to construct ATP's on ‘brown field’ sites. Brown field sites can be defined as areas which have previously been used for some other purpose i.e. old landfill sites, disused industrial sites, education and housing areas etc. It is important to note that these areas of different from ‘green field’ sites, which are defined as areas that have had no previous usage apart from agriculture and/or natural land.
[0180] FIG. 11 represents the cross-section of an in-situation sub-grade course and performance course construction profile 14 over an existing brown field substrate 4 - 5 :
1 . Turf surface 14 . Retaining curb stones 13 . In situation or preformed sub-grade course 4 . Non-porous capping layer 5 . Exist brown field sub structure
[0186] The preservation of green field areas is a high priority for national and local governments and it is preferable to re-use areas which have been made redundant. As a standard ATP base construction profile requires the excavation and removal of existing substrates below the level of the proposed pitch, this can pose a problem on brown field sites (depending on local conditions etc). If, for example, the proposed site is on an area of demolished industrial units, it is likely that the concrete and foundation will still be in-situation. Normally this would require complicated and costly removal. The principal system being proposed allows the pitch to be constructed over the existing ground without any removal.
[0187] The construction, base profiles and the installation methods described above (in-situation and pre-formed) remain the same and the capping layer 4 is formed over the exist ground 5 . The composition and the thickness of the system depend over what type of surface is being constructed. For example, a construction over an existing concrete or rubble floor will already have a great deal of load bearing and spread capacity, therefore the design of the layers can be designed to concentrate on shock absorption and drainage.
[0188] As has been indicated in the preceding description of the invention there are significant opportunities for reducing the amount of excavation on green field sport sites and for avoiding the need to break up existing flat substrates, such as concrete floors, on brown field sites.
[0189] According to the invention a substrate is formed from granular plastics material, which has been coated in binder to form a stable, substantially incompressible, water permeable or water retaining substrate. Surprisingly it has been proven that a particularly suitable material for this purpose is “end of life” plastics material, which is the plastics material that current processes cannot any longer recycle, because of its chemistry, because it is has already been recycled, because it is dirty or otherwise difficult to sort. Not only does this have environmental advantages, because the material no longer has to go to landfill or incineration, the material is also preserved for future reuse, re-processing or recycling.
[0190] As is indicated this sub-base may be formed as preform parts, but it is particularly advantageously used by forming appropriate layers in situ using existing pavement pavers, which typically lay down a 2½ metre wide layer of self levelling material, without, essentially any compaction, the only pressure on the material being that of the grader or scraper bar. This not only enables the system to be used with existing technology and existing skills, it is readily open to a range of uses in accordance with local practices and will level out minor undulations in the surface on which it has been laid.
[0191] The absence of compaction means that the granular material will adhere to where it contacts other granular material leaving a pattern of voids through the material so that it is pervious to water. If it is laid on an impermeable surface, the nature of the material formed is such that water will become subject to lateral capillary action whereby the water is ejected through the side edges of the substrate frequently avoiding the need for drains to be formed underneath the substrate location. It also means that the substrate can be laid flat, without the need for drainage grading, which occurs in most existing arrangements.
[0192] The binding materials can be Polyurethane, Bitumen or Polyofin displacements and may form between 8 and 20% of the substrate. It is desirable that the granules have a range of sizes in order to provide a good pattern of voids.
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A method of forming a substrate for a sports surface of a sports pitch includes the steps of: a) Agglomerating plastics materials; b) Granulating the agglomerated plastics materials to form granules having a predetermined range of sizes; c) In situ coating the granules with a binding material so that they form a fluent material; d) Forming a layer of the fluent material on the site of the sports pitch; and e) Setting the laid material such that the granules adhere where they contact each other to form a voided water permeable structure.
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RELATED APPLICATION
[0001] In accordance with 37 C.F.R 1.76, a claim of priority is included in an Application Data Sheet filed concurrently herewith. Accordingly, the present invention claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application 61/709,782 entitled “DRYWALL COMPOUND DISPENSING SYSTEM” filed on Oct. 4, 2012. The contents of each of the above referenced applications are herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to drywall compound dispensing devices, and more particularly to a dispensing system having quick change dispensing tools securable to a drywall compound pump.
BACKGROUND OF THE INVENTION
[0003] Drywall (also known as plasterboard, wallboard, or gypsum board), a panel product made of gypsum plaster pressed between two thick sheets of paper and/or polymer is used to construct interior walls or ceilings of residential and commercial buildings. Drywall panels normally range in thickness from ¼″ to ¾″. Application of different thicknesses or multiple layers can provide improved fire resistance qualities. The panels are attached to wood or metal studs by means of drywall fasteners, the most common known as drywall screws. Drywall joint compound is a white substance similar to plaster which is used to seal the joints between the panels, cover nail screw heads, and generally form a smooth or flat surface to provide a uniform texture over which paint or wall paper can be applied. Workers who specialize in drywall installation use a variety of specialized tools designed to increase their productivity. A bazooka automatic taper is one such tool that is specifically designed for dispensing drywall joint compound along with tape to cover seams and corners of freshly installed drywall.
[0004] Because joint compound applicators such as bazookas are difficult to fill, specialized tools have been developed for making the filling operation simpler for the technician. One of the more commonly used systems includes a manually-operable pump, known as a Drywall Mud Pump manufactured by Drywall Master of Forest Park, Ill. The manually operated pump has a bottom portion which is inserted into an open five gallon container or pail holding joint compound. The top end of the pump includes a hand-operable pump handle and a discharge port for attachment to a gooseneck tube. Typically, a gooseneck attachment tube is connected to the pump to allow the drywall mud to be pumped into a tool such as the bazooka. The gooseneck tube is generally J-shaped and includes an upper end and lower end portion. The upper end of the gooseneck tube is directly connected to the top end discharge port of the pump with bolts or screws, and an O-ring sealing element is disposed between the gooseneck and the pump. The lower end portion of the gooseneck includes an outlet which fits into a portion of the bazooka automatic taping machine. In operation, the bazooka automatic taping machine is placed into the gooseneck and the pump handle is manually operated to pump the joint compound from the open top container though the pump, through the gooseneck tube, and into the bazooka. One downside to this construction relates to the requirement of two people to complete the filling operation. The bazooka is a large tool, typically five feet long, requiring one person to hold the device in contact with the gooseneck while a second person operates the pump. This shortcoming is exacerbated when the five gallon pail gets low on joint compound, requiring the person pumping to stabilize the pail to pump the viscous joint compound.
[0005] Another shortcoming relates to the need to fill containers other than the bazooka to complete a job such as finishing flat boxes. The prior art goosenecks are one piece and secured to the pump with fasteners. In order to fill the boxes with joint compound, the gooseneck tube must be detached from the discharge port on the mud pump. Thereafter, a nozzle is attached to the discharge pump to facilitate filling of the flat box. A problem encountered with the direct connection of the gooseneck to the mud pump is the continual detachment and reattachment thereof which leads to wasted time, frustration to a user, and wear on the devices. The user must have tools readily available to unscrew the bolts or screws on the upper portion of the gooseneck from the discharge port on the mud pump. The different materials used for the fasteners and the pump, e.g. steel and cast aluminum, in combination with the joint compound often results in galvanic reaction and causes the bolts to seize. The soft nature of the cast aluminum often results in the threads pulling out of the pump when the fasteners are removed. Repairs may be completed in some cases; however, they are costly and time consuming, resulting in downtime and added expense.
[0006] Thus, what is lacking in the art is a system for quickly and easily attaching and changing dispensing attachments to a drywall compound pump. The system should include a base portion that remains secured to the mud pump. The base portion should be constructed and arranged to cooperate with a plurality of attachments without the necessity for tools. The attachments should be easily interchangeable for cooperation with a variety of boxes, bazookas, automatic tapers and the like.
SUMMARY OF THE INVENTION
[0007] The present invention relates to tools for finishing drywall. More specifically, the present invention is a system for use in dispensing drywall joint compound from a pail or container. The system comprises a base member that is permanently or semi-permanently securable to a manual joint compound pump and a plurality of attachments that are removably securable to the base member to provide various manners of dispensing joint compound. One end of the base member is constructed to function as a first portion of a quick connector. The plurality of attachments is provided with each attachment including the second portion of the quick connector. The cooperation between the first and second portions of the quick connector allow a technician to quickly change tools by hand to those that better suit his needs for improved efficiency. In a preferred embodiment, the base member is supplied with a gooseneck tool for filling bazooka automatic tape machines and a dual nozzle for filling various types of finishing boxes. The gooseneck attachment may be constructed and arranged to include tool holders which keep all of the attachments in a single place. In an additional embodiment, the tools may all be secured together with a tether. This construction eliminates the need to locate tools and attachments to complete a drywall finishing job; greatly improving efficiency and lowering cost of drywall finishing.
[0008] Accordingly, it is an objective of the present invention to provide a drywall compound dispensing system.
[0009] It is a further objective of the present invention to provide a drywall compound dispensing system that is constructed and arranged to cooperate with a hand operated drywall pump and includes a quick change tool arrangement which allows a user to quickly change dispensing tools.
[0010] It is another objective of the present invention to provide a drywall compound dispensing system wherein the quick change tool arrangement includes interlocking male and female components releasable and engagable by hand.
[0011] It is yet another objective of the present invention to provide a drywall compound dispensing system that includes a gooseneck attachment and a box filling attachment.
[0012] It is still yet another objective of the present invention to provide a drywall compound dispensing system that includes a dual nozzle for quicker and easier filling of a finishing box.
[0013] Yet another objective of the present invention is to provide a support bracket on the gooseneck attachment for supporting a bazooka automatic taper when the bazooka is attached to the outlet of the gooseneck.
[0014] It is a still further objective of the present invention to provide a gooseneck attachment containing a base plate for support and stability of the gooseneck as well as the pump during operation.
[0015] Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a perspective view of a prior art manual drywall compound pump and gooseneck filler;
[0017] FIG. 2 is a top perspective view of the first portion of the quick connector of the present invention;
[0018] FIG. 3 is a rear view of the first portion of the quick connector of FIG. 2 ;
[0019] FIG. 4 is a perspective view of one embodiment of the gooseneck attachment in accordance with the present invention;
[0020] FIG. 5 is a partial top perspective view of one embodiment of the gooseneck attachment secured to a drywall mud pump in accordance with the instant invention;
[0021] FIG. 6 is a top perspective view of the first portion of the quick connector of the present invention; and
[0022] FIG. 7 is a rear view of the first portion of the quick connector of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0023] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred, albeit not limiting, embodiment with the understanding that the present disclosure is to be considered an exemplification of the present invention and is not intended to limit the invention to the specific embodiments illustrated.
[0024] Referring to FIG. 1 , a state of the art manually operated drywall compound or mud pump 2 is illustrated with a prior art gooseneck attachment. The drywall compound pump 2 includes a bottom portion 5 that is constructed for insertion into a five gallon pail of drywall joint compound (not shown) while stabilizing leg 6 extends down the outside wall of the pail so that the foot pad 7 rests on a ground surface. The top portion of the drywall compound pump 2 includes a hand-operable lever (not shown) connected through a pivot 9 ( FIG. 5 ) to a pump rod 11 . The bottom portion of the pump rod 11 includes seals, valves and the like to cause the pump rod to pull drywall compound from the pail and force it through a discharge port 3 . The discharge port 3 includes an integrally formed flange 13 having threaded apertures 15 for securing dispensing tools to the discharge port 3 . FIG. 1 illustrates a gooseneck tube 4 secured to the pump assembly for filling a bazooka automatic taping machine. The gooseneck tube 4 includes a connection flange 17 welded to an upper end portion of the gooseneck tube. The lower end portion of the gooseneck tube 4 includes an outlet for attachment to a drywall applicator. The connection flange 17 is directly connected to the discharge port 3 of the pump 2 with threaded fasteners 19 . As shown, the fasteners 19 are typically constructed from a steel material, while the gooseneck tube and the pump are constructed from cast aluminum. Because the connection is pressurized during dispensing of the drywall compound, the compound often gets between the fastener and the pump causing a galvanic reaction therebetween. The galvanic reaction often causes the threads within the pump flange 13 to pull out with the fasteners, requiring replacement before the pump can be used again.
[0025] Referring to FIGS. 2-7 , various figures representing one embodiment of the drywall compound dispensing system are illustrated. The drywall dispensing system generally includes a base member 70 and a plurality of drywall compound dispensing nozzles. In a particularly preferred embodiment, the drywall compound dispensing system includes a base member 70 , a gooseneck tip 10 and a finishing box tip 50 . The base member 70 is generally constructed and arranged to be secured to the drywall compound pump in a permanent or semi-permanent manner. As shown in FIGS. 2-3 , the base member includes a connection flange 72 sized and shaped to cooperate with the discharge port flange 13 and includes a pair of apertures 74 sized and placed to align with the threaded or through apertures provided on the discharge flange 13 . A front side 82 of the connection flange 72 includes an outwardly extending first portion 84 of a quick connector. The first portion 84 of the quick connector is constructed and arranged to cooperate with a second portion 30 of a quick connector, secured to the tips, to allow quick connection between the tips and the pump without the necessity of tools. In one embodiment, the first portion of the quick connector includes a tube portion 86 . The tube portion includes an O-ring groove 88 and a lock indention 90 . The outside diameter of the tube portion 86 is sized to fit inside of a second quick connector portion 16 in a manner that substantially prevents drywall compound from seeping between the two components.
[0026] Referring to FIGS. 4-5 , the gooseneck tip 10 is generally constructed and arranged to cooperate with a bazooka type automatic tape applicator and includes an upper end portion 12 , a lower end portion 14 , and a central portion 38 . The gooseneck tip 10 has a tubular cross-section along its entire length to transfer drywall compound from the pump to the bazooka. The upper end portion 12 includes the second portion of the quick connector 16 . The second portion of the quick connector 16 is constructed and arranged to circumscribe the tube portion 86 of the base member 70 . The second portion of the quick connector 16 preferably has a bore 30 that is slightly larger than the tube portion of the base member 70 so that an inner bore of the second portion of the quick connector cooperates with the O-ring 80 positioned along the tube 86 to create a sealed connection. A manually-operable thumbscrew 34 is positioned on the second portion of the quick connector 16 to contact the outer diameter of the tube portion 86 . In this manner, when thumbscrew 34 makes contact with the outer diameter of the tube portion 86 , the frictional relationship allows the gooseneck tip 10 and mud pump 2 to maintain a seal. A lock indention 90 is sized to accept the distal end of the thumbscrew 34 to provide alignment and additional engagement between the two. It should be noted that while a thumbscrew is disclosed, other types of quick connectors suitable to create engagement between the base member and the tips may be utilized without departing from the scope of the invention. Such quick connectors may include, but should not be limited to ball locks, spring pins, collets and the like. The upper end portion 12 of the gooseneck tip has a substantially 90-degree bend 22 . The upper end portion 12 may also include a support plate 40 . The support plate is disposed on the substantially 90-degree bend 22 , opposite the second portion of the quick connector 16 ; however, the support plate may be located anywhere along the gooseneck tip 10 . The support plate 40 includes a rod member 42 bent into a semi-circular shape that is constructed and arranged to support a bazooka type tape applicator when the joint tape applicator is installed on the outlet 18 of the gooseneck tip 10 . The lower end portion 14 contains a substantially 180-degree bend 24 terminating in an outlet 18 . The outlet 18 is upwardly facing so as to connect to a bazooka type tape applicator (not shown). On the 180-degree bend 24 , a base plate 28 is mounted for support of the gooseneck tip 10 . The base plate 28 is sized and shaped to allow a user to step thereon while the gooseneck tip 10 and mud pump 2 are in use to maintain stability without the further use of hands. Between the upper end portion 12 and lower end portion 14 is a central portion 38 . The central portion 38 includes an L-shaped tip holder 36 . The L-shaped tip holder 36 is sized to fit within the inner bore of an additional tip member to retain the additional tip member with the gooseneck tip, shown in FIG. 5 . A tether 92 , in the form of a chain, cable or the like, may also be utilized to keep the tips in close proximity to the base member 70 . In this manner, a user can quickly change between tips as needed to complete a drywall job. In a preferred embodiment, the tubular cross section is round; however, any tubular shape suitable for cooperation with a bazooka automatic tape machine may be utilized without departing from the scope of the invention. The gooseneck tip is preferably constructed of aluminum; however, any metal or plastic suitable for transfer of drywall compound could be utilized without departing from the scope of the invention.
[0027] As shown in FIGS. 5-7 , the finishing box tip 50 is illustrated. The finishing box tip 50 includes a first end 52 and a second end 54 . The first end 52 includes a pair of diverging open ended nozzles 56 . Each nozzle 56 includes a nozzle tip 64 . The nozzle tips 64 are sized to fit within a finishing flat box (not shown) for filling it with joint compound. The second end 54 of the finishing box tip 50 comprises another second portion of the quick connector 16 and is constructed and arranged to circumscribe the tube portion 86 of the base member 70 , similar to the gooseneck connection. The second portion of the quick connector 16 preferably has a bore 30 that is slightly larger than the tube portion of the base member 70 , so that an inner bore of the second portion of the quick connector cooperates with the O-ring 80 positioned along the tube 86 to create a sealed connection. In use, the gooseneck is detached from the tube portion on the base member and the finish box tip is attached for facilitate in filling of a flat box, not shown. More specifically, the second end 54 of the finishing box tip 50 is attached to the tube portion 86 on the base member 70 . Not shown, it is contemplated that a manually-operable thumbscrew may be positioned on the second portion of the quick connector of the finishing box tip to contact the outer diameter of the tube portion. In this manner, when the thumbscrew makes contact with the outer diameter of the tube portion, the frictional relationship allows the finishing box tip 50 and mud pump 2 to maintain a seal. It should be noted that while a thumbscrew is contemplated, other types of quick connectors suitable to create engagement between the base member and the tips may be utilized without departing from the scope of the invention. Such quick connectors may include, but should not be limited to ball locks, spring pins, collets and the like.
[0028] As shown in FIG. 7 , an alternative seal between the discharge port of the mud pump and the connection flange is contemplated. The rear surface 76 of the connection flange 72 may be provided with an O-ring groove 78 and O-ring 80 . This construction minimizes the amount of drywall compound that can seep between the flanges 13 , 72 during operation of the pump.
[0029] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
[0030] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
[0031] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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The present invention relates to tools for finishing drywall. More specifically, the present invention is a system for use in dispensing drywall joint compound from a container. The system comprises a base member that is semi-permanently securable to a manual joint compound pump and a plurality of attachments that are removably securable to the base member to provide various manners of dispensing joint compound. One end of the base member is constructed to function as a first portion of a quick connector. Each of the plurality of attachments is provided with a second portion of the quick connector. The cooperation between the first and second portions of the quick connector allow a technician to quickly change tools by hand to those that better suit his needs for improved efficiency.
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CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the U.S. Patent classification definitions technical field of but not limited to; Class 273 Archery/Subclass 317+ and Class 124 Mechanical guns and projectors/subclass 23.1 bow, subclass 25 crossbow, subclass 25.6 compound bow, and more specifically to a unique and novel apparatus that provides protection to such as but not limited to, an archery bow's cam module, idler module, tension cable and string, stave reel, wheel etc. which are mounted at or near the extreme end of a bow stave from contact with objects which would cause damage to the aforementioned.
2. Prior Art
Archery in its purest form has long been associated with the Native American bow and arrow, and while the newest style of bow is the compound bow, it was invented in the mid-20th century with 20 th century technology. Said compound bow consisted of steel pulleys and/or cams on the ends of the staves, with a long string that criss-crosses the bow multiple times. One limb usually has an elliptical cam, which produces a sudden reduction in the draw weight of the bow when a certain point is reached. Another form had double elliptical cams but had timing problems. Bow material was commonly wood or fiberglass. Computer software had yet to be invented that could demonstrate stress and g-force generated upon staves, strings and elliptical pulleys. Arrow speed was comparably slow at 200 fps and archery bows had a typical “C” shape. Typically archery bows described can be bought in expensively.
In the 21 st century, computers and software technology have advanced archery as archery equipment has seen dramatic advances in aluminum and magnesium composite limb systems, parallel limb design, limb turrets, cam module, idler module, carbon tension cable and strings, power and buss cables, cable and string suppressors, inertia tungsten carbide weight disks embedded into cams and string grubs. The aforementioned advances and innovations have brought the modern compound bow to where it is today. Arrow speeds now reach 340 fps; computerized numerical controlled machines bend, form or vacuum composite material into variations of rectangular shapes with beyond parallel dual limbs tipped with cam modules, idler modules, string suppressors etc.
While archery equipment and compound bow performance advances have continued to rise, so has the price of this 21 st century technology. High performance archery bows cost upwards of $1,200. While there do exist many fanciful apparatus that will attach in all manners to an archers bow, they all have similar shortcomings which is none would provide adequate protection to said new and expensive 21 st century archery technology. Specifically the cam module and idler module elliptically ovidly shaped cams and associated power and buss cable's contact point on the take-up track of the cam without interfering with the aforementioned module(s) movement or sacrificing somewhere else.
For example, U.S. Pat. No. 7,730,883 discloses a bow cam protector that overlaps the cam with members extending beyond the cam. . . . While such a configuration may be suitable for providing limited cam protection, vibration dampening and a stand, the invention of the '883 patent does not provide protection to either said cam module and idler module elliptically ovidly shaped cams or associated power and buss cable's contact point on the take-up track of the cam. Also '883's said members extending beyond the cam could act as an undesirable hook while walking through thick forest while hunting.
U.S. Pat. No. 4,979,488 discloses a cam or eccentric wheel shield that quiets the sound of . . . and shields the movement of cams or a-centric wheels during movement and protects the wheels and the cable from becoming clogged, chipped or damaged. Disclosure of '488 is unique to 20 th century archery equipment but does not address the use of or the acceptance of 21 st century archery technology such as offset cam modules, idler module, string and cable suppressors or grubs. So also, said patent '488 is unlikely to withstand the g-force vibrations and recoil associated with 21 st century high performance archery bows. In addition, '488 interferes and blocks the mounting points for some string suppressors which are sold as stock equipment; and '488 interferes with cam module and idle module field adjustments.
Accordingly, a need remains for CAM BLADE in order to overcome the above-noted shortcomings. The non-limiting exemplary embodiments satisfies such a need by providing an apparatus that is convenient and easy to use, lightweight yet durable in design, versatile in its applications, and designed for easily and conveniently protecting cam module and idler module elliptically ovidly shaped cams and associated power and buss cable's contact point on the take-up track of the cam.
BRIEF SUMMARY OF THE INVENTION
In view of the foregoing background, it is therefore an object of the non-limiting exemplary embodiments to provide a brief summary of the invention and some of the advantages such as provides protection to: an archery bow's cam module, to the idler module, tension cable and string; provides protection to stave reel, cam, wheel etc. which are mounted at or near the extreme end of a bow stave. Another advantage is protection from contact with objects which would cause damage to the associated power and buss cable's contact point on the take-up track of the cam.
Described in one embodiment, CAM BLADE withstands g-shock from falling bow and describes material.
CAM BLADE position is detailed in another embodiment.
Described in one embodiment is the sweeping elliptically ovid shape.
In still another embodiment, CAM BLADE attachment by such as but not limited to, a threaded fastener through cam module.
Also an embodiment describes how CAM BLADE can be used on varying width, height and style of spokes within an archer's cam.
This invention CAM BLADE does not interfere with field adjustments to either the cam module.
These and other objects, features, and advantages of the invention are provided by description of the preferred embodiments.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
It is noted the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view showing CAM BLADE, in a preferred use installed on a compound bow's elliptically ovid shape cam module and in accordance with the non-limiting exemplary embodiments;
FIG. 2 is a cross-sectional end view showing CAM BLADE installed on a compound bow's elliptically ovid shape cam module;
FIG. 3 is a side view showing CAM BLADE installed on a compound bow's elliptically ovid shape cam module;
FIG. 4 is an inside view, end view and outside view of CAM BLADE.
Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the shapes, relative sizes or proportions shown in the figures.
DETAILED DESCRIPTION OF THE INVENTION
The non-limiting exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, this embodiment is provided so that this application will be thorough and complete, and will fully convey the true scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the figures.
The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not intended to serve as a complete description of all of the elements and features of apparatus and systems that utilize the structures or methods described herein. Many other embodiments may be apparent to those of skill in the art upon reviewing the disclosure. Other embodiments may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Additionally, the illustrations are merely representational and may not be drawn to scale. Certain proportions within the illustrations may be exaggerated, while other proportions may be minimized. Accordingly, the disclosure and the figures are to be regarded as illustrative rather than restrictive.
One or more embodiments of the disclosure may be referred to herein, individually and/or collectively, by the term “non-limiting exemplary embodiments” merely for convenience and without intending to voluntarily limit the scope of this application to any particular invention or inventive concept. Moreover, although specific embodiments have been illustrated and described herein, it should be appreciated that any subsequent arrangement designed to achieve the same or similar purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all subsequent adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the description.
The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b) and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all of the features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter.
The below disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments which fall within the true scope of the non-limiting exemplary embodiments. Thus, to the maximum extent allowed by law, the scope of the non-limiting exemplary embodiments is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.
References in the specification to “one embodiment”, “an embodiment”, “a preferred embodiment”, “an alternative embodiment” and similar phrases mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an embodiment of the invention. The appearances of the phrase “non-limiting exemplary embodiment” in various places in the specification are not necessarily all meant to refer to the same embodiment.
Directional and/or relationary terms such as, but not limited to, left, right, nadir, apex, top, bottom, vertical, horizontal, back, front and lateral are relative to each other and are dependent on the specific orientation of an applicable element or article, and are used accordingly to aid in the description of the various embodiments and are not necessarily intended to be construed as limiting.
The apparatus of this invention is referred to generally in FIGS. 1 / 4 and is intended to provide a perspective view showing CAM BLADE attached to a common 21 st century high performance compound bow's elliptically ovid cam module. It should be understood that the non-limiting exemplary embodiments may be used to describe similar apparatus and many different types of devices that could be protected by CAM BLADE and should not be limited to the uses described herein. The descriptor nomenclature legend that follows is not meant to be all encompassing but to aid the reader in understanding the figures within the drawings.
Item Number 1 : Cam Blade; Item Number 2 : T-Slot; Item Number 3 : T-Slot Fastener; Item Number 4 : Bow Stave; Item Number 5 : Power and buss cable; Item Number: 6 : Cam module, which is connected to its axis of rotation via radial support(s) 6 A (such as spokes) with opening(s) 6 B in or between said radial support(s) 6 A; Item Number 7 : Fastener; Item Number 8 : Cam Blade Lip;
Viewing FIGS. 1 / 4 , a perspective view, CAM BLADE is shown with descriptors numbered 1 thru 6 illustrating a first embodiment of the invention. CAM BLADE is constructed of a ridged lightweight material that withstands shock g-force delivered from a dropped archery compound bow and said material has a composition that minimizes abrasions. The 1 Cam Blade is situated symmetrically about and parallel to 6 cam module and/or respectively to the idler module (mirrored and not shown), and sandwiches said 6 cam module or idler module at the outer most point where said cam or idler module would naturally receive damage.
A further embodiment also viewed on FIGS. 1 / 4 , is the angel in which said 1 cam blade is positioned. Said 1 cam blade begins at or near the underside of 4 bow stave and sweeps away from said 4 bow stave to a point on 6 cam module that is appropriate to provide damage and abrasive protection to 6 Cam module and 5 Power and buss cable.
An additional embodiment viewed on FIGS. 1 / 4 , 1 cam blade is shaped in an elliptical ovid shape paralleling the 6 cam module and does not interfere with field adjustments to said 6 cam module.
Viewing FIG. 2 , cross-sectional view, the reader can see a cross section of 1 cam blade, said 1 Cam Blade contains at least one 2 T-slot which 3 T-Slot fastener is inserted into and tightened against opposing 7 fastener sandwiching 6 cam module.
Also in FIG. 2 , the reader can view 3 T-slot fastener and 7 fastener rest against the underside of 6 cam module thus restricting outward movement of said 1 cam blade.
In an alternate embodiment, viewing FIG. 3 , side view showing 1 cam blade mounted onto 6 cam module. Many types of 6 cam modules exist therefore the 2 T-Slot is used to avoid the many different configurations of cam spokes, various outside diameters, elliptically ovidly shaped 6 cams, wheels, pulleys etc. By using the 2 T-Slot, said 3 T-Slot fasteners can be placed in a wide array of positions.
FIG. 4 is an inside view, end view and outside view included for clarity. Additionally, said 1 cam blade has an interior 8 Cam Blade lip which rest upon the outer most edge of said 6 cam adjacent to 5 Power and buss cable. With the 8 cam blade lip, said 3 T-slot fastener and 7 fastener, said 1 Cam Blade is prohibited from moving radially inward or outward.
Such a structural configuration provides the unexpected and unpredictable advantage of rigidity while also providing protection from damage to such as but not limited to, an archer's elliptically ovidly shaped 6 cam module and associated 5 power and buss cable without interfering with either said module movement, said power and buss cable nor said take up track of 6 cam module.
While the invention has been described with respect to a certain specific embodiment, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. In particular, with respect to the above description, it is to be realized that the optimum dimensional relationships for the parts of the non-limiting exemplary embodiments may include variations in size, materials, shape, form, function and manner of operation.
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The apparatus disclosed begins exterior of archery bow stave cam slot and traverses a generally elliptically ovidly path convexed and roughly shaped paralleling exterior perimeter edge movement of an elliptically ovid cam module, and a portion of the apparatus is formed to terminate at a point on cam module that is appropriate to provide damage and abrasive protection to cam module and power and buss cable without interference of the aforementioned. Said apparatus is shaped cross sectionally in a manner that is small, light weight and does not interfere with the normal operation of an archery bow.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of International Patent Application No. PCT/CN2015/081253 with an international filing date of Jun. 11, 2015, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201410765621.9 filed Dec. 12, 2014. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a method for preparing high molecular weight poly(L-lactic acid) (PLLA) with high performance.
[0004] 2. Description of the Related Art
[0005] Poly(lactic acid) is widely used in medicine. It features excellent biocompatibility. Conventional preparation methods of commercial-scale poly(lactic acid) employ stannous octoate as catalyst. However, the tin salt is cytotoxic and difficult to separate from the product.
SUMMARY OF THE INVENTION
[0006] In view of the above-described problems, it is one objective of the invention to provide a method for preparing high molecular weight poly(L-lactic acid). The resulting poly(L-lactic acid) features high biocompatibility and high performance.
[0007] To achieve the above objective, in accordance with one embodiment of the invention, there is provided a method for preparing high molecular weight poly(L-lactic acid) (PLLA) with high performance, the method comprising:
a) providing a biogenic guanidine (BG) as a catalyst, and a nontoxic acid salt of an essential metal trace element as an activator (Act), and adding the catalyst, the activator, and L-lactide monomer to a polymerization reactor; and b) evacuating under vacuum and charging the polymerization reactor with nitrogen for three consecutive times to remove air, and allowing the L-lactide monomer to undergo bulk polymerization under vacuum.
[0010] The bulk polymerization comprises a first reaction stage and a second reaction stage. In the first stage, a reaction temperature is between 125 and 140° C., a reaction pressure is between 0.4 and 0.6 torr, a reaction time is between 16 and 24 hours, and a resulting product is medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of between 4.0×10 4 and 5.0×10 4 . In the second reaction stage, a reaction temperature is between 140 and 160° C., a reaction pressure is between 0.1 and 0.3 torr, a reaction time is between 25 and 60 hours, and a final product is a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of between 4.0×10 5 and 5.5×10 5 .
[0011] The bulk polymerization is represented by the following equations:
[0012] the first reaction stage of bulk polymerization:
[0000]
[0013] the second reaction stage of bulk polymerization:
[0000]
[0014] * LLA: L-lactide;
[0015] m-PLLA: medium molecular weight poly-L-lactic acid;
[0016] h-PLLA: high molecular weight poly-L-lactic acid;
[0017] BG: biogenic guanidine;
[0018] Act: activator.
[0019] In a class of this embodiment, the final product is nontoxic and has the following performance index: a polydispersity index (PDI) is less than or equal to 1.70, a melting point (Tm) is greater than or equal to 185° C., a crystallinity (Xc) is greater than or equal to 80.2%, with snowy white color.
[0020] In a class of this embodiment, the final product has the following performance index: Mw=5.5×10 5 , PDI=1.50, Tm=188° C., and Xc=82.9%.
[0021] In a class of this embodiment, the catalyst biogenic guanidine is an organic guanidine derivative resulting from arginine metabolism and energy storage/release, comprising arginine, glycocyamine, creatine, creatinine, phosphocreatine; the nontoxic acid salt is a salt of K, Fe, Zn, or Ca; the catalyst and the activator constitute a two-component catalyst system, and a dosage of the two-component catalyst system accounts for between 0.001 and 0.05 wt. % of that of the L-lactide monomer.
[0022] In a class of this embodiment, the nontoxic acid salt is a carbonate, acetate, lactate, or glycolate.
[0023] In a class of this embodiment, the nontoxic acid salt is K 2 CO 3 , FeCO 3 , (CH 3 CH(OH)COO) 2 Zn, CaCO 3 , (CH 3 CH(OH)COO) 2 Ca, CH 3 COOK, (HOCH 2 COO) 2 Zn, or (CH 3 COO) 2 Ca.
[0024] An identification result from Chinese authoritative organization shows that the high performance high molecular weight poly(L-lactic acid) contains no cytotoxicity.
[0025] Advantages of the method for preparing poly(L-lactic acid) are summarized as follows.
[0026] 1. The method employs a nontoxic two-component (a catalyst+an activator) catalyst system, which is environmentally friendly.
[0027] 2. The method involves no solvent and employs bulk polymerization, no waste water, waste air and waste residue are produced, so it is environmentally friendly.
[0028] 3. The final product contains no LLA monomer and no cytotoxicity, and thus it is a biodegradable polymer, with high biosafety.
[0029] 4. The final product can be prepared according to practical requirements and has the following performance index: a weight average molecular weight (Mw) is 4.0-5.5×10 5 , a polydispersity index (PDI) is less than or equal to 1.70, a melting point (Tm) is greater than or equal to 185° C., a crystallinity (Xc) is greater than or equal to 80.2%, with snowy white color. The product has wide applications in the medicine and pharmacy fields.
[0030] 5. The final product has the following performance index: Mw=5.5×10 5 , PDI=1.50, Tm=188° C., and Xc=82.9%, with snowy white color.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0031] For further illustrating the invention, experiments detailing a method for preparing poly(L-lactic acid) are described below. It should be noted that the following examples are intended to describe and not to limit the invention.
[0032] LLA monomer, a catalyst and an activator are added to a polymerization reactor. The dosage of the two-component catalyst system accounts for between 0.001 and 0.05 wt. % of that of the LLA monomer. The polymerization reactor is vacuumized and charged with nitrogen for three consecutive times for air removal, and then is allowed for bulk polymerization, which comprises a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature is between 125 and 140° C., a reaction pressure is between 0.4 and 0.6 torr, a reaction time is between 16 and 24 hours, and a resulting product is medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of between 4.0×10 4 and 5.0×10 4 . Thereafter, the second reaction stage is followed, where a reaction temperature is between 140 and 160° C., a reaction pressure is between 0.1 and 0.3 torr, a reaction time is between 25 and 60 hours, and a final product is a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of between 4.0×10 5 and 5.5×10 5 .
Example 1
[0033] 200.0 g of LLA, 2.0 mg of arginine, and 2.0 mg of K 2 CO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 125° C., a reaction pressure was 0.4 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 5.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 140° C., a reaction pressure was 0.1 torr, a reaction time was 40 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 5.5×10 5 . The final product has the following performance index: Mw=5.5×10 5 , PDI=1.50, Tm=188.1° C., Xc=82.9%, and snowy white in color.
Example 2
[0034] 200.0 g of LLA, 2.0 mg of arginine, and 2.0 mg of K 2 CO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 125° C., a reaction pressure was 0.4 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 5.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 140° C., a reaction pressure was 0.1 torr, a reaction time was 39 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 5.4×10 5 . The final product has the following performance index: Mw=5.4×10 5 , PDI=1.51, Tm=187.9° C., Xc=82.5%, and snowy white in color.
Example 3
[0035] 200.0 g of LLA, 2.0 mg of arginine, and 2.0 mg of K 2 CO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 125° C., a reaction pressure was 0.4 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 5.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 140° C., a reaction pressure was 0.1 torr, a reaction time was 38 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 5.3×10 5 . The final product has the following performance index: Mw=5.3×10 5 , PDI=1.53, Tm=187.8° C., Xc=82.4%, and snowy white in color.
Example 4
[0036] 200.0 g of LLA, 2.0 mg of arginine, and 2.0 mg of K 2 CO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 125° C., a reaction pressure was 0.4 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 5.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 140° C., a reaction pressure was 0.1 torr, a reaction time was 37 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 5.2×10 5 . The final product has the following performance index: Mw=5.2×10 5 , PDI=1.53, Tm=187.8° C., Xc=82.3%, and snowy white in color.
Example 5
[0037] 200.0 g of LLA, 2.0 mg of arginine, and 2.0 mg of K 2 CO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 125° C., a reaction pressure was 0.4 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 5.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 140° C., a reaction pressure was 0.1 torr, a reaction time was 36 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 5.1×10 5 . The final product has the following performance index: Mw=5.1×10 5 , PDI=1.52, Tm=187.6° C., Xc=82.2%, and snowy white in color.
Example 6
[0038] 100.0 g of LLA, 2.0 mg of arginine, and 2.0 mg of K 2 CO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 125° C., a reaction pressure was 0.4 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 5.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 140° C., a reaction pressure was 0.1 torr, a reaction time was 40 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 5.0×10 5 . The final product has the following performance index: Mw=5.0×10 5 , PDI=1.54, Tm=187.4° C., Xc=82.1%, and snowy white in color.
Example 7
[0039] 150.0 g of LLA, 4.5 mg of arginine, and 4.5 mg of K 2 CO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 125° C., a reaction pressure was 0.4 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 5.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 140° C., a reaction pressure was 0.1 torr, a reaction time was 36 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 4.5×10 5 . The final product has the following performance index: Mw=4.5×10 5 , PDI=1.58, Tm=186.8° C., Xc=82.1%, and snowy white in color.
Example 8
[0040] 200.0 g of LLA, 8.0 mg of arginine, and 8.0 mg of K 2 CO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 125° C., a reaction pressure was 0.4 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 5.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 140° C., a reaction pressure was 0.1 torr, a reaction time was 25 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 4.0×10 5 . The final product has the following performance index: Mw=4.0×10 5 , PDI=1.51, Tm=185.4° C., Xc=80.5%, and snowy white in color.
Example 9
[0041] 80.0 g of LLA, 5.6 mg of glycocyamine, and 3.2 mg of FeCO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 132° C., a reaction pressure was 0.5 torr, a reaction time was 20 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 4.5×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 150° C., a reaction pressure was 0.2 torr, a reaction time was 45 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 5.5×10 5 . The final product has the following performance index: Mw=5.5×10 5 , PDI=1.56, Tm=188.0° C., Xc=82.7%, and snowy white in color.
Example 10
[0042] 80.0 g of LLA, 5.6 mg of glycocyamine, and 3.2 mg of FeCO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 132° C., a reaction pressure was 0.5 torr, a reaction time was 20 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 4.5×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 150° C., a reaction pressure was 0.2 torr, a reaction time was 38 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 4.9×10 5 . The final product has the following performance index: Mw=4.9×10 5 , PDI=1.61, Tm=187.4° C., Xc=81.9%, and snowy white in color.
Example 11
[0043] 80.0 g of LLA, 5.6 mg of glycocyamine, and 3.2 mg of FeCO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 132° C., a reaction pressure was 0.5 torr, a reaction time was 16 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 4.5×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 150° C., a reaction pressure was 0.2 torr, a reaction time was 32 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 4.4×10 5 . The final product has the following performance index: Mw=4.4×10 5 , PDI=1.58, Tm=186.4° C., Xc=80.6%, and snowy white in color.
Example 12
[0044] 80.0 g of LLA, 5.6 mg of glycocyamine, and 3.2 mg of FeCO 3 were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 132° C., a reaction pressure was 0.5 torr, a reaction time was 20 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 4.5×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 150° C., a reaction pressure was 0.2 torr, a reaction time was 26 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 4.0×10 5 . The final product has the following performance index: Mw=4.0×10 5 , PDI=1.61, Tm=185.2° C., Xc=80.4%, and snowy white in color.
Example 13
[0045] 50.0 g of LLA, 25.0 mg of phosphocreatine, and 25.0 mg of (CH 3 CH(OH)COO) 2 Ca were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 140° C., a reaction pressure was 0.6 torr, a reaction time was 24 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 4.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 160° C., a reaction pressure was 0.3 torr, a reaction time was 60 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 5.5×10 5 . The final product has the following performance index: Mw=5.5×10 5 , PDI=1.60, Tm=187.9° C., Xc=82.6%, and snowy white in color.
Example 14
[0046] 50.0 g of LLA, 25.0 mg of phosphocreatine, and 25.0 mg of (CH 3 CH(OH)COO) 2 Ca were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 140° C., a reaction pressure was 0.6 torr, a reaction time was 24 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 4.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 160° C., a reaction pressure was 0.3 torr, a reaction time was 55 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 4.8×10 5 . The final product has the following performance index: Mw=4.8×10 5 , PDI=1.58, Tm=187.3° C., Xc=81.8%, and snowy white in color.
Example 15
[0047] 50.0 g of LLA, 25.0 mg of phosphocreatine, and 25.0 mg of (CH 3 CH(OH)COO) 2 Ca were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 140° C., a reaction pressure was 0.6 torr, a reaction time was 24 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 4.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 160° C., a reaction pressure was 0.3 torr, a reaction time was 50 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 4.6×10 5 . The final product has the following performance index: Mw=4.6×10 5 , PDI=1.62, Tm=186.8° C., Xc=81.5%, and snowy white in color.
Example 16
[0048] 50.0 g of LLA, 25.0 mg of phosphocreatine, and 25.0 mg of (CH 3 CH(OH)COO) 2 Ca were added to a polymerization reactor. The polymerization reactor was vacuumized and charged with nitrogen for three consecutive times for air removal, and then was allowed for bulk polymerization, which comprised a first reaction stage and a second reaction stage. In the first reaction stage, a reaction temperature was 140° C., a reaction pressure was 0.6 torr, a reaction time was 24 hours, and a resulting product was medium molecular weight poly-L-lactic acid (m-PLLA) having a weight average molecular weight (Mw) of 4.0×10 4 . Thereafter, the second reaction stage was followed, where a reaction temperature was 160° C., a reaction pressure was 0.3 torr, a reaction time was 45 hours, and a final product was a high molecular weight poly-L-lactic acid (h-PLLA) having a weight average molecular weight of 4.0×10 5 . The final product has the following performance index: Mw=4.0×10 5 , PDI=1.59, Tm=185.1° C., Xc=80.2%, and snowy white in color.
[0049] While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.
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A method for preparing high molecular weight poly(L-lactic acid) with high performance, including: a) providing a biogenic guanidine (BG) as a catalyst, and a nontoxic acid salt of an essential metal trace element as an activator (Act), and adding the catalyst, the activator, and L-lactide monomer to a polymerization reactor; b) evacuating under vacuum and charging the polymerization reactor with nitrogen for three consecutive times to remove air, and allowing the L-lactide monomer to undergo bulk polymerization under vacuum. The bulk polymerization includes a first reaction stage and a second reaction stage, which are separately carried out at different temperatures, pressures, and reaction times.
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FIELD OF THE INVENTION
[0001] This invention relates to an edge formation process for aluminum solid electrolytic capacitors.
BACKGROUND OF THE INVENTION
[0002] Electrolytic capacitors with excellent high frequency characteristics are in high demand due to speed requirements of circuits for devices such as computers and wireless communications. In addition, high capacitance is required in the low voltage circuits that are used in these devices. Conductive polymers such as polypyrrole, polyaniline, polythiophene, and their derivatives, are finding increasing use as cathodes for electrolytic capacitors because such polymers have much higher conductivity than the liquid electrolytes and manganese dioxide cathodes currently used in these capacitors.
[0003] A wet electrolytic capacitor has an anode metal, a dielectric, a liquid electrolyte, and a cathode. Valve metals such as tantalum, aluminum, and niobium are particularly suited for the manufacture of high surface area electrolytic capacitors. The valve metal serves as the anode, and an oxide of the valve metal, coated by electrochemical oxidation of the valve metal surfaces, serves as the dielectric. The process of electrochemically coating a valve metal with a dielectric oxide is called formation. In order to maximize the dielectric surface area, and hence increase the volumetric efficiency of the capacitor, the valve metal substrates are porous bodies. These porous bodies can take the form of etched foils or slugs of compressed powder. The liquid electrolyte is impregnated into the porous body. A high surface area cathode completes the circuit. Etched aluminum foil is a particularly preferred anode material for wet electrolytic capacitors.
[0004] In the manufacture of wet aluminum electrolytic capacitors, the aluminum foil is etched to high surface area, coated with a dielectric oxide film, slit to the proper width, and then cut to length. During the slitting and cutting-to-length operations, the dielectric oxide on the edges of the foil is damaged and bare aluminum is exposed. The foil is then wound, placed in a can (along with the cathode), and filled with a non-aqueous fill electrolyte. The non-aqueous fill electrolyte is composed of, for example, borates in non-aqueous solvents containing a very small amount of water. After filling with electrolyte, the cans are sealed to prevent electrolyte from escaping and to keep additional water out.
[0005] A critical part of conditioning a wet aluminum electrolytic capacitor is repairing the damage to the dielectric oxide on the edges of the slit and cut-to-length foil and any damage to the dielectric oxide on the face of the foil that incurred during the winding operation. If these edges are not re-formed, the capacitor will have a high leakage current. The non-aqueous fill electrolytes, containing a very small amount of water, are very efficient in re-forming oxide on the edges.
[0006] In the manufacture of a solid aluminum electrolytic capacitor with a conductive polymer cathode, the foil etching, forming, and slitting are done in a similar manner to that of wet aluminum electrolytic capacitor. However, the conductive polymer is not efficient at re-forming a dielectric film on the slit and cut edges and at repairing damaged oxide on the face. Therefore, this must be done in a separate step before the conductive polymer is impregnated into the aluminum/aluminum oxide anode.
[0007] Re-forming the slit and cut edges can be accomplished by immersing the elements in a formation bath or a series of formation baths. The requirements for these edge formation baths are threefold: 1) They must form a high quality dielectric oxide on the cut edges, 2) They must repair any damage to the dielectric oxide on the face of the element that was damaged during the slitting and cutting to length operation, and 3) They must not damage the dielectric oxide already on the face of the element. In addition, the formed dielectric oxide needs to have excellent hydration resistance.
[0008] Hydration resistance is critical for aluminum solid electrolytic capacitors with conductive polymer cathodes. After impregnation with the conductive polymer, the capacitors are washed extensively in water to remove excess reactants and reactant byproducts. This washing is at elevated temperature (>50° C.). The aluminum oxide film is exposed to conditions very conducive to hydration during this washing process, and, therefore, the aluminum oxide film must have a high degree of hydration resistance. Hydration of the oxide during the washing process, or on subsequent storage after washing, can result in hydrated oxide in the weld zone and this hydrated oxide is difficult or impossible to weld through to make a good attachment to the lead frame.
[0009] A high degree of hydration resistance is also required during storage or use of capacitors in high humidity environments. If the oxide becomes hydrated during use, the capacitor leakage current will increase, or the capacitor can become a short circuit.
[0010] It was discovered that prior art electrolytes have deficiencies when used for edge formation of aluminum anodes intended for use in solid aluminum electrolytic capacitors with conductive polymer cathodes. The fill electrolytes used in wet aluminum capacitors are not suitable for use outside a sealed can because of their toxic nature and their propensity to adsorb water from the air. Thus they cannot be used in open, mass production electrolyte baths.
[0011] Electrolytes used for the production of the original aluminum oxide film are also not completely suitable because they are designed to form oxide on a freshly etched surface or a hydrated oxide surface and not designed to form oxide on cut edges and to repair oxide on the face (cf. U.S. Pat. Nos. 3,796,644; 4,113,579; 4,159,927; 4,481,084; 4,537,665; 4,715,936). In addition, compromises must be made in the selection of an electrolyte because of the high current efficiency needed to economically produce a dielectric oxide over the entire etched aluminum surface.
[0012] Slitting and cutting the foil to length mechanically damages the edges and this mechanical damage should be repaired before or during the formation of the dielectric oxide film on the edge.
[0013] Several electrolyte systems have been considered for the edge formation of aluminum electrolytic capacitors with a solid conductive polymer cathode. Low leakage current and high capacitance can be achieved by producing a thick, porous layer on the edge using aqueous solutions of oxalic acid, followed by forming a barrier layer with aqueous solutions of ammonium adipate (EP 1,028,441 A1). A flowchart of this prior art edge formation process is shown in FIG. 2. The parts are first anodized in oxalic acid, rinsed, and dried. This produces a thick, porous layer on the edge. Since oxalic acid has a low pH, it also tends to remove the very outer layers of oxide from the surface. The parts are then formed in ammonium adipate, rinsed, and dried. This step produces a dielectric oxide on the edge. This is followed by a depolarization step and another formation in ammonium adipate, rinse, and dry. The resulting films are unstable toward hydration. The hydration resistance of the pre-existing dielectric oxide is impaired because of the attack by oxalic acid. Neither ammonium adipate alone or the oxalic acid-ammonium adipate system are capable of forming a hydration resistant oxide on the edges. This leads to problems with leakage current instability in production, welding of the capacitors to the lead frame, and long-term stability towards hydration. It is desirable to have an edge formation electrolyte system, which provides a product with a hydration resistant oxide.
BRIEF SUMMARY OF THE INVENTION
[0014] It was discovered that edge formation in an aqueous citrate solution followed by formation in an aqueous phosphate solution imparts high hydration resistance to the foil and results in a minimal loss of capacitance.
[0015] The invention is directed to a process for edge forming a slit and cut-to-length foil having a dielectric oxide film on at least one surface comprising forming the foil in an aqueous citrate electrolyte, preferably an aqueous ammonium citrate electrolyte, depolarizing the foil, and forming the foil in an aqueous phosphate electrolyte, preferably an ammonium dihydrogen phosphate electrolyte. Using this formation process, a foil with excellent hydration resistance and capacitance is produced.
[0016] The invention is further directed to a process for edge forming a slit and cut-to-length aluminum foil having a dielectric oxide film on at least one surface comprising forming the foil in an aqueous ammonium citrate electrolyte, then depolarizing the foil, and then forming the foil in an aqueous ammonium dihydrogen phosphate electrolyte wherein the foil is not anodized in an aqueous acid electrolyte prior to forming the foil in an aqueous ammonium citrate electrolyte.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 shows a flowchart of the process of edge formation according to the invention.
[0018] [0018]FIG. 2 shows a prior art edge formation process.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Aluminum is etched to a high surface area and formed with a dielectric oxide and then slit to a width suitable for the production of solid electrolytic capacitors. The foil is then cut to length and welded to a carrier bar. A masking material is applied to the foil to define the area that will be subsequently edge formed.
[0020] A flowchart of the edge formation process is shown in FIG. 1. The foils are heat treated in an oven at elevated temperature to reduce the amount of surface hydration and to bring the foil surface to a well-defined state of wettablity. The elevated temperature is generally from about 250° C. to about 550° C. and the foils are heat treated from about 2 minutes to about 12 hours. Preferably the foils are heat treated at a temperature from about 300 to about 350° C. for about 15 to 30 minutes.
[0021] The foils are first edge formed in an aqueous citrate electrolyte (1 st edge formation). The citrates can be soluble citrates salts of alkali metal, amine, or ammonium cations. Preferably, the electrolyte is ammonium citrate with a pH in the range of about 4 to about 9, preferably in the range of about 5 to about 7. The concentration of the citrate in water is from about 0.1 wt % to about 10 wt %, preferably about 0.5 wt % to about 5 wt %, more preferably about 1 wt %. The temperature of the electrolyte is from about 0° C. to about 90° C., preferably from about 50° C. to about 90° C., more preferably about 55° C. The time of formation depends on the concentration and temperature and is typically from about 3 minutes to about 20 minutes, preferably, about 10 minutes.
[0022] The foils are then rinsed of the aqueous citrate, dried to remove excess water, and depolarized. The depolarization step exposes any hydrate, trapped gas, or voids in the oxide produced during previous formation steps. The foils may be depolarized by heating the foils to an elevated temperature or by soaking on open circuit in a hot borate or citrate solution Preferably, the foils are depolarized by heating the foils to about 250° C. to about 550° C., for about 30 seconds to about 2 hours, preferably about 300° C. for 30 minutes.
[0023] The foils are then edge formed again in an aqueous phosphate electrolyte, preferably ammonium dihydrogen phosphate (2 nd edge formation). The concentration of the phosphate in water is from about 0.01 wt % to about 5 wt %, preferably about 0.05 wt % to about 2 wt %, more preferably about 0.1 wt %. The temperature of the phosphate electrolyte is from about 0° C. to about 90° C., preferably about 25° C. to about 90° C., more preferably about 55° C. The time of formation depends on the temperature and concentration and is typically from about 3 minutes to about 20 minutes, preferably about 7 minutes. The phosphates can be soluble phosphate salts of alkali metal, amine, or ammonium cations. Preferably, the electrolyte is ammonium dihydrogen phosphate at a concentration of from about 0.01 wt % to about 5 wt %. Optionally, the phosphate electrolyte can contain glycerine to prevent any airline corrosion of the foil (Melody et al., US S/N).
[0024] After the formation in phosphate, the foils are given a final rinse in water and dried to remove excess water.
EXAMPLE 1
[0025] Etched foil with a formed layer such that the withstanding voltage was 13 V (capacitance ˜119 μF/cm 2 ) was slit to a width of 3 mm. The foil was cut to a length of 11 mm and attached to stainless steel carrier bars. A polyimide masking material was applied to each of the foil elements on the carrier bar so that an area of 3 mm×6.1 mm was defined on each foil element.
[0026] The carrier bars were divided into four groups. Each group was edge formed in the electrolytes shown in Table I. Group 1 was edge formed according to the process flow of FIG. 2. Groups 2, 3, and 4 were edge formed according to the process flow of FIG. 1. Each group was hydrated in deionized water for 90 minutes at 70° C. The foils were then reformed in 9% ammonium adipate (at 50° C.) for 24 minutes and the charge under the reformation curve was calculated from the measured current. The last column of Table I shows the calculated charge in millicoulombs per square cm of geometric surface area.
[0027] Group 1, anodized in oxalic acid followed edge formation in ammonium adipate, was severely discolored and had a large capacitance decrease (capacitance went from 17.7 to 3.2 μF/element) after the hydration test. A charge of >700 mC/cm 2 was passed during the reform after hydration. The color change is indicative of hydrated oxide formation. The large capacitance decrease occurs because of the formation of massive amounts of hydrated oxide, which plug the fine pores of the etched foil.
[0028] In contrast, Groups 2, 3, and 4, that had no oxalic acid anodization and were edge formed in ammonium citrate or ammonium dihydrogen phosphate, were not discolored, had little change in capacitance, and the charge passed during the reformation was ˜50 to 100 times less than the case of oxalic acid/ammonium adipate formation.
TABLE I 1 st Edge 2 nd Edge Reform Charge After Anodization Formation Formation Hydration mC/cm 2 OA AA AA 701 None AC AC 23.2 None AC ADP 10.7 None ADP ADP 5.87
EXAMPLE 2
[0029] Three batches of multi-layer aluminum capacitors with a conductive polymer cathode were fabricated. Aluminum foil was etched, formed to a withstanding voltage of 13 volts, and slit to 3 mm in width. The foil was then cut into 11 mm lengths and attached to carrier bars. A masking line was applied to the foil. Each batch was then divided into two groups. One group was edge formed in ammonium dihydrogen phosphate using the process flow in FIG. 1. The other group was anodized in the prior art electrolyte system of oxalic acid followed by edge formation in ammonium adipate using the process flow in FIG. 2.
[0030] A second masking line was applied. A conductive polymer layer of poly (3,4-ethylenedioxythiophene) was applied by chemical polymerization using techniques known to those skilled in the art (U.S. Pat. No. 4,910,645, Jonas et al.). The capacitors were then rinsed of polymerization byproducts and carbon and silver paste layers were applied. The capacitor elements were cut off the carrier bar. The cathode end of the capacitors were attached to the lead frame with a silver adhesive and the positive ends were welded to the lead frame by conventional resistance welding techniques. Four capacitors were attached to each lead frame to make a 4-layer device. The capacitors were then encapsulated in an epoxy case by transfer molding.
[0031] Table II shows the capacitance of the devices after molding. The capacitance of the hydration resistant formation system of ADP was 9% less than the prior art system using oxalic acid anodization followed by edge formation in ammonium adipate. This is disadvantageous as high capacitance in a given package volume is desired.
TABLE II 1 st Edge 2 nd Edge Capacitance Anodization Formation Formation (μF) None ADP ADP 48.15 OA AA AA 52.85
EXAMPLE 3
[0032] Two batches of capacitors were fabricated in a similar manner to Example 2. One half of each batch was edge formed in AC electrolyte using the process flow in FIG. 1. The other half of each batch was anodized in the prior art electrolyte system of OA followed by edge formation in AA using the process flow in FIG. 2. The average capacitance of the two batches is shown in Table III. In this case, the capacitance was only 3.6% less than for the OA and AA system.
TABLE III 1 st Edge 2 nd Edge Capacitance Anodization Formation Formation (μF) None AC AC 52.34 OA AA AA 54.32
EXAMPLE 4
[0033] Five batches of capacitors were fabricated in a similar manner to Example 2. One half of each batch was edge formed in AC electrolyte followed by ADP electrolyte using the process in FIG. 1. The other half of each batch was anodized in the prior art electrolyte system of OA followed by edge formation in AA using the process flow in FIG. 2. The average capacitance of the five batches is shown in Table IV. The capacitance for the AC/ADP edge formation system was 4% less than for the OA/AA system. This is similar to the capacitance difference in Example 3, but, as shown in Example 1, the hydration resistance of the AC/ADP system is better than the AC/AC system.
[0034] The capacitors were further tested by exposing them to a temperature of 85° C. and a relative humidity of 85% for 168 hours. After exposure, the leakage current of the group processed in ammonium citrate and ammonium dihydrogen phosphate was less than half that of the group processed in the prior art system of oxalic acid and ammonium adipate.
TABLE IV Leakage Current After 168 hrs. 85 1 st Edge 2 nd Edge Capacitance C/85% RH Anodization Formation Formation (μF) (μA) None AC ADP 51.48 5.0 OA AA AA 53.65 12.0
[0035] Thus, the edge formation electrolyte system of ammonium citrate followed by ammonium dihydrogen phosphate gives the best combination of capacitance and hydration resistance.
[0036] While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth in the appended claims.
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A process for edge forming a slit and cut-to-length foil having a dielectric oxide film on its face comprising forming the foil in an aqueous citrate electrolyte, preferably an aqueous ammonium citrate electrolyte, depolarizing the foil, and forming the foil in an aqueous phosphate electrolyte, preferably an ammonium dihydrogen phosphate electrolyte. Using this formation process, a foil with excellent hydration resistance and capacitance is produced.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of pending application Ser. No. 09/054,183, filed Apr. 2, 1998 now U.S. Pat. No.6,055,589.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic unit for use with for example an IEEE 1394 serial bus, in particular, to a technology for transmitting a large amount of data using an asynchronous packet.
2. Description of the Related Art
A communication system that connects electronic units (hereinafter referred to as units) such as a personal computer, a digital video cassette recorder (hereinafter referred to as DVCR), and a digital television receiver with an IEEE 1394 serial bus and that sends/receives packets of a digital video signal, a digital audio signal, and a control signal therebetween has been proposed.
FIG. 1 shows an example of such a communication system. The communication system comprises a monitor 11 , a DVCR 12 , and a tuner 13 as units. The monitor 11 and the DVCR 12 are connected with an IEEE 1394 serial bus cable 14 . The monitor 11 and the tuber 13 are connected with an IEEE 1394 serial bus cable 15 .
In the communication system, an isochronous communication (referred to as ISO communication) for periodically transmitting real time data such as a digital video signal and a digital audio signal between units and an ASYNCHRONOUS communication (ASYNC communication) for non-periodically transmitting such as a unit operation control command and a unit connection control command can be performed. For example, a digital video signal and a digital audio signal selected by the tuner 13 can be reproduced as video information and audio information by the monitor 11 . Alternatively, such signals can be recorded by the DVCR 12 . In addition, a channel selection control command of the tuner 13 , an operation mode setup command of the DVCR 12 , and so forth can be sent from the monitor 11 to the relevant units through the IEEE 1394 serial bus cables 14 and 15 .
In the communication system shown in FIG. 1, there is an AV/C (Audio Visual/Control) command set as commands for controlling AV (Audio Visual) units. In the AV/C command set, a status command for inquiring a status has been defined. In addition, as a response to the status command, status information of a designated unit that is sent back as an operand has been defined.
The data amount of the state may be very large. For example, as shown in FIG. 2, a television broadcast has a hierarchical structure composed of a network layer, a multiplex layer, a service layer, and a component layer. Thus, the data amount of a status command for inquiring each service (broadcast channel) that the digital broadcast tuner is currently selecting may exceed 30 bytes. In the digital broadcast, a plurality of services can be placed on one stream. Thus, a response to an inquiry is required for a plurality of services. Consequently, the data amount of one response may become several hundred bytes.
On the other hand, since the sizes of a command register (buffer) and a response register (buffer) of an FCP (Function Control Protocol) of the IEEE 1394 serial bus are up to 512 bytes, a command packet and a response packet whose sizes exceed 512 bytes cannot be transmitted and received. In addition, it is not assured that a real unit have a buffer that can store data of 512 bytes (the data amounts of currently available buffers are in the range from several ten bytes to one hundred and several ten bytes). When the buffer size is limited, information corresponding to an inquired state cannot be obtained.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention is made from the above-described point of view. An object of the present invention is to provide a unit that allows a large amount of data that exceeds the size of a buffer thereof to be obtained and an information transmitting method thereof.
The present invention is a method for transmitting information between each electronic unit, comprising the steps of (a) transmitting information whose amount does not exceed a predetermined data amount, (b) determining whether or not the predetermined data amount is larger than a desired information amount, (c) when the determined result at step (b) is No, transmitting remaining information for the predetermined amount or less, and (d) repeating the steps (a) to (c) until there is no remaining information.
The present invention is an electronic unit for communicating with a plurality of units, comprising first means for physically communicating with the plurality of units, buffer means for temporarily storing data that is transmitted by the first means; and controlling means for controlling the first means and the buffer means, wherein the controlling means transmits information whose amount does not exceed a predetermined data amount, determines whether or not the predetermined data amount is larger than a desired information amount, when the determined result is No, transmits remaining information for the predetermined amount or less, and repeats these operations until there is no remaining information.
The present invention is a storing medium storing a program for an electronic unit for communicating with a plurality of units, comprising first means for physically communicating with the plurality of units, buffer means for temporarily storing data that is transmitted by the first means, and controlling means for controlling the first means and the buffer means, the program causing the controlling means to perform the functions of (a) transmitting information whose amount does not exceed a predetermined data amount, (b) determining whether or not the predetermined data amount is larger than a desired information amount, (c) when the determined result at step (b) is No, transmitting remaining information for the predetermined amount or less, and (d) repeating the steps (a) to (c) until there is no remaining information.
The above, and other, objects, features and advantage of the present invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing the structure of a communication system using IEEE 1394 serial bus;
FIG. 2 is a schematic diagram showing a hierarchical structure of a television broadcast;
FIG. 3 is a block diagram showing the structure of principal portions of a DVCR according to the present invention;
FIG. 4 is a schematic diagram showing the internal structure of a memory shown in FIG. 3;
FIG. 5 is a schematic diagram showing an example of an object list stored in a descriptor;
FIGS. 6A and 6B are schematic diagrams showing an example of information that represents current output signals stored in the descriptor;
FIG. 7 is a schematic diagram showing the structure of DIRECT SELECT OBJECT control command corresponding to a tuner sub-unit;
FIG. 8 is a schematic diagram showing the structure of DIRECT SELECT OBJECT status command;
FIG. 9 is a schematic diagram showing the structure of a response to the DIRECT SELECT OBJECT status command;
FIGS. 10A and 10B are flow charts showing a process for checking objects selected in the tuner sub-unit shown in FIG. 3
FIG. 11 is a schematic diagram showing an example of the structure of a response to the DIRECT SELECT OBJECT status command in the case that the capacity of a buffer is sufficient;
FIG. 12 is a schematic diagram showing an example of the content of information of selection_specification;
FIG. 13 is a schematic diagram showing an example of the structure of a response to the DIRECT SELECT OBJECT status command in the case that the capacity of the buffer is insufficient;
FIG. 14 is a schematic diagram showing an example of the structure of a descriptor read command; and
FIG. 15 is a schematic diagram showing an example of the structure of the descriptor read command.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Next, with reference to the accompanying drawings, an embodiment of the present invention will be described.
FIG. 3 is a block diagram showing the structure of principal portions of a DVCR according to the present invention. The DVCR comprises a tuner sub-unit 1 , a controller 5 , a memory 6 , and an IEEE 1394 ASYNC block 7 .
The tuner sub-unit 1 has an analog broadcast tuner 2 and a digital broadcast tuner 3 . The analog broadcast tuner 2 receive a television broadcast signal through an antenna (ANT) 1 . The digital broadcast tuner 3 receives a television broadcast signal through an antenna (ANT) 2 . A signal of a channel selected by the analog broadcast tuner 2 is sent to a recording portion (DVCR sub-unit) through a sub-unit output plug P 1 . A stream from a transponder selected by the digital broadcast tuner 3 is sent to a demultiplexer 4 . The demultiplexer 4 selects at least one service and sends the selected service to a recording portion and an IEEE 1394 ISO block through a sub-unit output plug P 0 . The demultiplexer 4 branches service information of the stream to the controller 5 . The sub-unit output plugs P 0 and P 1 are output terminals in the logical meaning and it is not required that they are physical output plugs.
The controller 5 controls the entire DVCR. In addition, the controller 5 creates an object list corresponding to service information received from the demultiplexer 4 and writes the object list to the memory 6 . Moreover, the controller 5 sends/receives a command and response to/from another unit through the IEEE 1394 ASYNC block 7 and an IEEE 1394 serial bus 8 . Furthermore, the controller 5 writes information of signals that are currently being output from the sub-unit output plugs P 0 and P 1 to the memory 6 .
The memory 6 has a particular area referred to as a descriptor as shown in FIG. 4 . In the descriptor, the above-mentioned object list and information of signals that are currently being output are written. FIG. 5 shows an example of the object list. The object list is created corresponding to the multiplex layer, the service layer, and the component layer shown in FIG. 1 . FIG. 6A shows the structure of a list (plug list) that shows plugs of the tuner sub-unit and objects that are currently being output from these plugs. This list is referred to as plug tuner object list. FIG. 6B shows a real example of the plug tuner object list. As shown in FIG. 6B, there are two types of object entry describing method. The first method is a detailed type for describing specifications in detail. The second method is a reference type for referencing another list.
The IEEE 1394 ASYNC block 7 assembles a command and a response created by the IEEE 1394 ASYNC block 7 as an ASYNC packet and sends the ASYNC packet to the IEEE 1394 serial bus 8 . In addition, the IEEE 1394 ASYNC block 7 disassembles an ASYNC packet received from the IEEE 1394 serial bus 8 into a command and a response and sends the command and the response to the controller 5 . At this point, the command and the response are temporarily stored in the buffer memory (that has a transmission buffer and a reception buffer).
Next, a process for checking objects selected by the tuner sub-unit 1 shown in FIG. 3 will be described. First of all, the structure of a command and a response used in the process will be described.
Direct Select Object command as a tuner sub-unit command selects at least one service, multiplexed stream, or component that is being broadcast and outputs the selected service, multiplexed stream, or component to a designated sub-unit plug. A control command designates the selection. A status command inquires what is currently being selected.
FIG. 7 shows the structure of a control command. In FIG. 7, source_plug represents an output plug of the tuner sub-unit. subfunction removes, appends, or replaces a designated object of a designated plug.
tuner_object_selection_specification is a parameter necessary for selection. It is supposed that the amount of information of tuner_object_selection_specification is around 10 to 50 bytes. When a command transmitter unit designates a plurality of objects, even if the size of the buffer memory of the IEEE 1394 ASYNC block is not sufficient, the objects can be selected by dividing them into a plurality of responses with subfunction:append.
FIG. 8 shows Direct Select Object status command. The Direct Select Object status command inquires what is currently being output to a designated plug. FIG. 9 shows a response of the Direct Select Object status command.
Next, with reference to a flow chart shown in FIGS. 10A and 10B, a process for checking objects selected by the tuner sub-unit 1 shown in FIG. 3 will be described.
At step S 1 , the Direct Select Object status command is transmitted. In other words, another unit (for example, the monitor unit) connected to the IEEE 1394 serial bus 8 shown in FIG. 3 places a command as shown in FIG. 8 in an ASYNC packet and sends the resultant ASYNC packet to the IEEE 1394 serial bus 8 through the IEEE 1394 ASYNC block. The packet is input to the IEEE 1394 ASYNC block 7 shown in FIG. 3 . The packet is temporarily stored in the buffer memory 9 and then read by the controller 5 .
The controller 5 analyzes the received command and checks signals that are currently being output to a designated plug (in this case, the sub-unit plug P 0 ). In other words, the controller 5 checks information of signals that are currently being output with the descriptor stored in the memory 6 . As exemplified in FIGS. 6A and 6B, the information describes the number of entries of objects for each plug. Thus, the controller 5 reads information of the plug P 0 , creates a response with the structure shown in FIG. 9, and sends the response back to the relevant unit.
However, the content of the response depends on the size of the buffer memory 9 of the IEEE 1394 ASYNC block 7 and the full length of tuner_object_selection_specification in the response. When the size of one tuner_object_selection_specification is 30 bytes and four objects are currently being output to the plug P 0 , the total amount of data of the response becomes 120 bytes.
In this case, when the size of the transmission buffer of the buffer memory 9 is sufficient, the controller sends a response as shown in FIG. 11 back to the relevant unit. In this case, operand [ 0 ] is stable. With operand [ 3 ] to [x], information of four selection_specification [ 0 ] to [ 4 ] is sent back to the relevant unit. FIG. 12 shows an example of the content of each selection_specification.
On the other hand, when the size of the transmission buffer of the buffer memory 9 is for example 100 bytes, information of four objects cannot be sent back to the relevant unit. Thus, the controller sends a response as shown in FIG. 13 back to the relevant unit. In this case, operand [ 1 ] is incomplete. The value of number_of_object_selection_specification of operand [ 2 ] is the number of objects (=3) that can be sent back rather than the number of objects that are currently being output from the plug P 0 . With operand [ 3 ], information of three selection_specification [ 0 ] to [ 2 ] is sent back to the relevant unit.
An ASYNC packet containing the response is received by the command transmitter unit through the IEEE 1394 serial bus 8 (at step S 2 ). The response is sent to the controller through the IEEE 1394 ASYNC block of the command transmitter unit. The controller references the status field of the response (at step S 3 ).
When the status field is stable, as shown in FIG. 11, the response contains information of all objects. Thus, the command transmitter unit completes the process.
On the other hand, when the status field is incomplete, the response contains information of objects that can be sent back as shown in FIG. 13 . Thus, information of signals that are currently being output is read from the descriptor stored in the memory 6 . In the following description, a process for a packet transmitted between a command transmitter unit and a command receiver unit (the DVCR shown in FIG. 3) is omitted.
The command transmitter unit sends a command for reading a plug list of the descriptor (at step S 4 ). The controller 5 of the command receiver unit reads the plug list as shown in FIGS. 6A and 6B from the descriptor stored in the memory 6 and sends the plug list as a response to the command transmitter unit. The command transmitter unit checks list_id=xx of plug 0 from the plug list in the response (at step S 5 ). In this case, it is assumed that xx=0101.
Next, the command transmitter unit transmits a command for checking the number of entries of objects in the plug list of list_id=xx (in this case, xx=0101) to the command receiver unit. The command transmitter unit determines the number n of entries of objects corresponding to the response (at step S 6 ). In this case, it is assumed that n=4.
At step S 7 , the command transmitter unit initially sets k=0 and sends a command for reading an object of a k-th entry of a plug list_id=xx of the descriptor to the command receiver unit. Thereafter, the command transmitter unit collects information of the object of the k-th entry corresponding to the response. After the command transmitter unit has collected the information for n entries, it completes the process (from steps S 8 to S 10 ).
Next, a command and a responses at step S 9 will be described.
FIG. 14 shows an example of the structure of a command (READ DESCRIPTOR, list_id=xx, entry=k) for reading an object of a k-th entry of a flag list_id=xx of the descriptor. data_length=0 of operand [ 5 ] represents that the command transmitter unit requires to read all objects with an entry number k.
FIG. 15 shows an example of the structure of a response to the command shown in FIG. 14 . data_length=yy of operand [ 5 ] represents the length of data sent with the response. entry_length of operand [ 8 ] represents the length of the object with the entry number k. When the size of the transmission buffer in the buffer memory 9 of the IEEE 1394 ASYNC block 7 shown in FIG. 3 is 100 bytes and the entry length is 30 bytes, information of one entry can be sent with one response. Thus, with yy=30 and zz=30, 30 bytes are read from offset address 0000 designated by operands [ 6 ] and [ 7 ] and sent. If the size of the transmission buffer of the buffer memory 9 is smaller than 30 bytes, (for example, the size is 10 bytes), with yy=10 and zz=30, the offset address is shifted by 10 bytes and sent as three responses.
Thus, with READ DESCRIPTOR command, when the command receiver unit cannot send to the command transmitter unit a response with information required by the command transmitter unit, the command receiver unit sends information of the maximum bytes that the command receiver unit can handle back to the command transmitter unit. In addition, since the command transmitter unit can freely designate an address and data length, it can send large amount of data with a plurality of responses.
As described above, according to the present invention, from a unit with a limited size of a transmission buffer, a large amount of data that exceeds the buffer size can be extracted.
Having described a specific preferred embodiment of the present invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to that precise embodiment, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or the spirit of the invention as defined in the appended claims.
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A method for transmitting information between each electronic unit, comprising the steps of (a) transmitting information whose amount does not exceed a predetermined data amount, (b) determining whether or not the predetermined data amount is larger than a desired information amount, (c) when the determined result at step (b) is No, transmitting remaining information for the predetermined amount or less, and (d) repeating the steps (a) to (c) until there is no remaining information.
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FIELD OF THE INVENTION
This invention relates generally to the field of medicinal chemistry. More specifically, to derivatives of a subclass of triterpenoid acids that have multi-medicament properties, that is derivatives of the lupanes, formulations containing such, and their use to prevent or treat certain diseases.
BACKGROUND OF THE INVENTION
Triterpenoids comprise a class of natural products that are reported to have medicament properties including anti-ulcer, anti-inflammatory, anti-allergy, anti-hepatitis and antiviral activities. As shown below, some examples of this class of molecules exhibit a ring structure having either 5 six membered rings, or 4 six membered rings and one five membered ring. Members of this latter classification are termed lupanes.
Perhaps one of the most studied of the triterpenoids is glycyrrhetinic acid, shown below, and derivatives thereof. For instance, certain glycyrrhetinic acid derivatives can prevent or heal gastric ulcers. Doll, R. et al., Lancet 11: 793 (1962). Among such compounds known in the art are carbenoxolone (U.S. Pat. No. 3,070,623), glycyrrhetinic acid ester derivatives having substituents at the 3-O position (U.S. Pat. No. 3,070,624), amino acid salts of glycyrrhetinic acid (Japanese Patent Publication JP-A-44-32798), amide derivatives of glycyrrhetinic acid (Belgian Patent No. 753773), amide derivatives of 11-deoxoglycyrrhetinic acid (British Patent No. 1346871), cicloxolone (Journal of Antimicrobial Chemotherapy, 18:B: 1845-200(1986), and glycyrrhizic acid and its derivatives (Chem. Pharm. Bull. 39(1): 112-115), (1991).
Additionally, U.S. Pat. No. 3,934,027 shows 18-β-glycyrrhetinic acid amides that are useful as antiulcer agents. U.S. Pat. No. 4,173,648 shows 3-β-hydroxy-18-β-olean-9-en-3O-oic acids also for treating ulcers.
Finally, WO 93/09129 describes certain triterpene compounds that exhibit anti-inflammatory activity. ##STR2##
Triterpenoids that exhibit a ring structure having 4 six membered rings and one five membered ring, are termed lupanes. Betulinic acid, a member of this class of natural products, has the following structure: ##STR3##
Similar to other triterpenoids, betulinic acid is known to have certain medical applications, including use as an anticancer drug. See, for example, JP 87,301,580. Anti-cancer applications are premised on the observation that cells require an adequate level of polyamines to grow at an optimal rate, and that cell growth can be inhibited by drugs that interfere with the enzymatic synthesis of polyamines. Four enzymes are known to be involved in the synthesis of polyamines: ornithine decarboxylase, S-adenosylmethionine decarboxylase, spermidine synthase and spermine synthase. Heby, O., Adv. Enzyme Regul., 24: 103-124, (1985). The activities of the two decarboxylases are rate limiting, and betulinic acid is a known inhibitor of ornithine decarboxylase. Yasukawa, K. et al. Oncology 48: 72-76 (1991). Its capacity to inhibit ornithine decarboxylase is, at least in part, responsible for its anti-cancer activity.
Although there have been some studies on the derivization of triterpenoids, particularly as related to glycyrrhetinic acid, as discussed above, little work has been done describing derivatives of betulinic acid. Choi et al have shown that betulinic acid 3-monoacetate, and betulinic acid methyl ester exhibit ED 50 values of 10.5 and 6.8 ug/ml, respectively, against P-388 lymphocytic leukemia cells. Choi, Y-H et al., Planta Medica vol. XLVII, pages 511-513, (1988).
It will be appreciated that because of the medicament properties of betulinic acid, it would be desirable to identify regions of the molecule that could be chemically modified in order to synthesis analogues or derivatives that are active against a wider spectrum of cancers, or that can be used to treat diseases other than cancer.
The lupanes, and specifically betulinic acid, have been reported to be effective anti-inflammatory agents. The anti-inflammatory activity of betulinic acid is, at least in part, due to its capacity to inhibit enzymes involved in leukotriene biosynthesis, including 5-lipoxygenase. Sotomatsu, S., et al., Skin and Urology 21: 138 (1959) and Inoue, H., et al., Chem. Pharm. Bull. 2: 897-901 (1986). Thus, a further reason to identify new betulinic acid derivatives is to take advantage of betulinic acids multi-medicament properties, and to produce medicaments that can be used to treat different diseases.
SUMMARY OF THE INVENTION
A first object of the invention is a description of triterpenoids, and preferably derivatives or analogues of the lupanes.
A second object of the invention is a description of derivatives or analogues of the lupane, betulinic acid, that have multi-medicament properties, including inhibition of ornithine decarboxylase, inhibition of certain enzymes involved in leukotriene biosynthesis, including 5-lipoxygenase, and the hithertofore unknown property of binding to certain selectins.
A third object of the invention is a description of preferred derivatives or analogues of the triterpenoid, betulinic acid, consisting of preferred modifications at the 3 position of betulinic acid on the E ring of the triterpenoid core structure, such modifications consisting of binding a glucoside, directly or indirectly thereto, thus increasing their medicament properties.
A fourth object of the invention is the description of derivatives or analogues of betulinic acid, that have the following structural formula (1): ##STR4## wherein: Y is OR 1 , NR 1 2 , O - M 1 ;
R 1 is H, LOWER ALKYL,
M 1 is Na + , K + , Mg ++ , Ca ++ ions;
each R 2 is independently CH 2 OR 1 or CH 3 ;
each R 3 is independently H, CH 3 , lower alkyl, COY, CH 2 OH, CH 2 OCH 2 CH=CH 2 , CH 2 OSO 3 - M 1 ;
each Z is independently NHR 1 2 , NR 1 Ac, NR 1 Bz, H, OCH 3 , lower alkyl, OH, OSO 3 - M 1 , OCH 2 CH=CH 2 , OCH 2 CO 2 H or O-glucoside;
each X is independently O, S, NR 1 or NR 2 1
each W is independently C=O, C=CR 1 2 , CR 1 CR 1 3 , CR 1 -CR 1 2 OR 1 , COR 1 -CR 1 OR 1 , COR 1 CR 1 2 OR 1 , CR 1 CR 1 2 NR 1 2 , CR 1 CR 1 2 OCR 1 COY, CHR 4 ;
R 4 is H, OH, OSO 3 - M 1 , or NH(CH 2 )nNH 2 , where n=1-8, or NH-Ph-NH 2 where Ph=an phenyl or naphthyl rings substituted with up to 3 amine functionalities and the remaining substitutions can be H, R 1 , R 2 or COY;
R 5 and R 6 are independently H, CH 3 , or taken together form a 5 or 6 membered carbocyclic ring.
A fifth object of the invention is to provide a pharmaceutical formulation containing the compound of formula (1).
A sixth object of the invention is a description of methods to treat or prevent disease by administering an effective amount of the aforementioned derivatives or analogues of betulinic acid, which diseases include cancer, autoimmunity, (i.e., arthritis), and the inflammatory response.
A seventh object of the invention is a description of methods to image sites of disease by administering labeled derivatives or analogues of betulinic acid of structural formula (1) and locating the labeled derivatives at a disease site in the body.
These and other objects, advantages and features of the present invention will become apparent to those persons skilled in the art upon reading the details of the isolation, structure, formulation and usage of the invention compounds as more fully set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention may be better understood and its numerous objects, advantages and features will become apparent to those skilled in the art by reference to the accompanying drawings as follows:
FIG. 1 is a cross-sectional schematic view showing the interaction between white blood cells and activated endothelial cells; and
FIG. 2 is a cross-sectional schematic view showing how compounds of the invention may act as selectin ligands and thus be used as pharmaceuticals to block E-selectin.
FIG. 3 shows the inhibition of cancer cell adhesion to E-selectin by compound (3) and betulinic acid.
FIG. 4 shows the inhibition of cancer cell adhesion to E-selectin by compound (3) and betulinic acid. The results shown in this figure are from a different experiment than the results shown in FIG. 3.
FIG. 5 shows the inhibitory effects of compound (3) on P-selectin binding to sLex.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Before the present compounds and compositions, and processes for isolating and using such are described, it is to be understood that this invention is not limited to the particular compositions, methods or processes described as such and may, of course, vary as would be known by the skilled practitioner of this art. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting since the scope of the present invention will be limited only by the appended claims.
It must be noted that as used in this specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a ligand" includes mixtures of compounds, reference to "an ELAM-1" includes reference to mixtures of such molecules, reference to "the formulation" or "the method" includes one or more formulations, methods and/or steps of the type described herein and/or which will become apparent to those persons skilled in the art upon reading this disclosure and so forth.
Glucoside is defined to include glucose, fucose, galactose, mannose, neutral or charged sugars, arabinose, xylose and chemically related sugars.
Unless defined otherwise 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. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described herein. All publications mentioned herein are incorporated herein by reference.
Some standard abbreviations used in connection with the present invention include: BSA, bovine serum albumin; DEAE, diethylaminoethyl; DMSO, dimethylsulfoxide; ELAM-1, endothelial/leukocyte adhesion molecule-1; HPTLC, high performance thin layer chromatography; LECAM-1, leukocyte/endothelial cell adhesion molecule-1; MOPS, 3-[N-Morpholino]propanesulfonic acid; NANA, N-acetylneuraminic acid; PVC, polyvinylchloride; TLC, thin layer chromatography; TFA, trifluoroacetic acid; Tris, tris (hydroxymethyl) aminomethane.
General Overview
Here and throughout the description of the invention, different stereo-configurations of the invention compounds are not shown but are understood to be encompassed by this disclosure and the appended claims.
One use of the compounds of the instant invention is to treat diseases that have, as one component of the disease, unwanted cell-cell adhesion. Numerous such diseases are well known to the skilled practitioner of this art and include unwanted inflammation, tumor metastasis, autoimmune diseases and others. FIGS. 1 and 2 pictorially present the application of the invention compounds in the inflammatory context.
FIG. 1, a cross-sectional view of a blood vessel 1. The vessel wall 2 is lined internally with endothelial cells 3. The endothelial cells 3 can be activated causing the cells 3 to synthesize ELAM-1 which is displayed as a triangular surface receptor 4. Both red blood cells 5 and white blood cells 6 flow in the vessel 1. The white blood cells 6 display carbohydrate compounds 7 which have chemical and physical characteristics which allow the compounds 7 to bind to the receptors 4. Once the ligand 7 binds to the receptor 4, the white blood cell 6 is brought through the vessel wall 2 as is shown with the white blood cell 6A. The white blood cells 6B brought into the surrounding tissue 8 can have positive effects, such as fighting infection, and negative effects, such as unwanted inflammation.
Referring now to FIG. 2, the inventors have produced compounds 7 apart from their presence on the surface of white blood cells 6. These isolated compounds 7A adhere to ELAM-1 by themselves and can be formulated into pharmaceutical compositions, which when administered will effectively block the ELAM-1 and prevent the adhesion of a receptor 7 connected to a white blood cell 6. By administering pharmaceutically effective amounts of compounds 7A, some, but not all, of the white blood cells will not reach the surrounding tissue. By slowing the rate at which the white blood cells reach the surrounding tissue, inflammation can be prevented and/or alleviated.
It is known that for an acute inflammatory response to occur, circulating neutrophils must bind to and penetrate the vascular wall and access the site of injury. Several molecules have been implicated in this interaction, including a family of putative carbohydrate compounds and their receptors. One molecule which has been previously isolated and identified is the endogenous carbohydrate ligand for endothelial leukocyte adhesion molecule-1 (hereinafter ELAM-1) and the ligand for LECAM-1. Surprisingly, one of the properties of the compounds of the invention is that they are selectin ligands. The present invention involves the characterization of the selectin ligand properties of the compounds shown in structural formula 1.
For certain cancers to spread throughout a patients body, a process termed metastasis, cell-cell adhesion must take place. Specifically, cancer cells must migrate from their site of origin and gain access to a blood vessel to facilitate colonization at distant sites. A critical aspect of this process is adhesion of cancer cells to endothelial cells that line the blood vessel wall, a step prior to migrating into surrounding tissue. This process can be interrupted by the administration of compounds of the invention which generally aid in blocking cell-cell adhesion. Accordingly, compounds of the invention can be used to retard the spread of cancer cells which display receptors which adhere to a compound of formula I.
Triterpenoid Acid Derivatives--Assays for Biological Activity
Derivatives of betulinic acids encompassed by general structural formula I can be tested for biological activities in accordance with certain assay procedures as will now be described.
Leukotriene Biosynthesis
Several assays can be performed to assess the inhibitory activity of the invention compounds against enzymes involved in leukotriene biosynthesis. For instance, leukotriene biosynthesis from arachidonic acid commences with 5-lipoxygenase oxidation of arachidonic acid to form 5-hydroperoxyeicosatetraenoic acid (5-HPETE), and in turn, leukotriene A4 and 5-hydroxyeicosatetraenoic acid (5-HETE). Assays for 5-lipoxygenase are known in the art and can be readily performed as described by Shimuzu, T., et al., Proc. Natl. Acad. Sci. USA 81: 693-698 (1984); and Epan, R., et al., J. Biol. Chem. 260: 11554-11559 (1985).
5-Lipoxygenase catalyzes the oxidative metabolism of arachidonic acid to 5-hydroxyperoxyeicosatetranoic acid (5-HPETE), the initial reaction leading to the formation of certain leukotrienes. Thus, compounds that inhibit 5-lipoxygenase will have significant medical applications that require regulating or lowering leukotriene levels. Thus, the compounds of the instant invention are assayed for their capacity to inhibit 5-lipoxygenase using a crude enzyme preparation from rat basophilic leukemia cells (RBL-1) (Shimuzu, T., Radmark, O. and Samuelsson, B. Proc. Natl. Acad. Sci. USA 81: 698-693 (1984) and Egan, R. W. and Gale, P. H. J. Biol. Chem. 260: 11554-11559 (1985)).
Anti-Inflammatory Activity
The arachidonic acid (AA), murine skin inflammation model, described by Harris, R. R. et al. (Skin Pharmacol 3: 29-40 (1990)) may be used to test the anti-inflammatory activity of the invention compounds relative to betulinic acid. Arachidonic acid is known to induce an inflammatory response and the compounds were tested for their capacity to inhibit the response.
Briefly, the compounds at an appropriate concentration are dissolved in a suitable solvent, and applied to a rodent ear immediately following application of arachidonic acid (AA). A control of AA alone is run. About 90 minutes later a 6 mm disk of each ear is removed and weighed. The percent inhibition of swelling caused by AA alone is calculated for the betulinic acid derivatives of the invention and compared to betulinic acid.
Anti-metastatic Activity
Certain cancer cells are known to adhere to E-selectin via E-selectin ligands on their cell surface, and this event is one component of the metastatic process. Thus, the anti-metastatic activity of the betulinic acid derivatives of the instant invention may be determined by assaying their capacity to prevent cancer cell adhesion to E-selectin. The assay generally consists of combining the appropriate test compound, an E-Selectin chimera which contains an IgG tail, a detection system consisting of biotinylated anti-human Ig (Fc specific), and streptavidin-alkaline phosphatase all in a suitable reaction solution. The mixture is rotated briskly on a rotary platform at room temperature for about 30-60 minutes. Particulate matter is removed by centrifugation, and the soluble fraction is transferred onto 96-well microtiter plates containing glutaraldehyde fixed LS174T colon carcinoma cells. This cell line is known to adhere to E-selectin. After 60 minutes at 37° C., plates are washed and E-selectin chimera bound to cells is quantified by addition of pNPP substrate in 1M diethanolamine buffer containing 0.1 mg/ml MgCl 2 at pH 9.8. Plates are developed in the dark and read at 405 nm. The IC 50 values are calculated and are the lowest concentrations from serial two-fold dilutions (quadruplicate wells at each concentration) which inhibits cell binding by 50% or more relative to the control.
Selectin Binding Assays
Such assays can take several formats including cell based assays that employ cells which express the desired cell surface selectin receptor. Foxall, C. et al., Journal of Cell Biology 117: 895-902 (1992). The cells are used as probes to screen compounds by determining if the compounds adhere to the cells under assay conditions known to those skilled in the art. Alternatively, Elisa based assays can be utilized to identify invention compounds that bind to a chosen selectin. Such assays are described by S. R. Watson, C. Fennie, and L. A. Lasky, Nature 349: 164-167, (1991); S. R. Watson, Y. Imai, C. Fennie, J. Geoffrey, M. Singer, S. D. Rosen, L. A. Lasky, J. Cell Biol. 115: 235-243; (1991) or S. R. Watson, Y. Imai, C. Fennie, J. S. Geoffrey, S. D. Rosen, L. A. Lasky, Journal of Cell Biology, 110: 2221-2229, (1991) and Foxall, C. et al., Journal of Cell Biology, 117: 895-902 (1992).
Conjugates
It should be pointed out that various "linker" groups can be attached to the betulinic acid derivatives of the present invention and the linker groups can be used to attach various additional compounds such as pharmaceutically acceptable drugs. By using the linker various conjugates are formed i.e. ligand-linker-drug conjugates are formed which provide effective drug delivery systems for the drug which is linked to the ligand compound of the invention. It is especially preferred to attach a drug with anti-inflammatory characteristics in that the ligand binds to ELAM-1 which is associated with inflammation. Accordingly, non-steroidal anti-inflammatory drugs (NSAIDs) such as naproxen or ibuprofen which act as anti-inflammatory agents could be administered bound to the ligand and could be administered systemically in smaller amounts than usual while obtaining an equivalent effect or even greater anti-inflammatory effect at the site of inflammation. The drug could be attached by an enzymatically cleavable linker cleaved by an enzyme such as an esterase. Any other drugs which might be attached include, but are not limited to, antibiotics, vasodilators and analgesics. Such a drug delivery system would reduce any systemic effect normally caused by the drug in that the drugs could be administered in amounts of one-half to one-tenth the normal dose and still obtain the same anti-inflammatory result at the site of inflammation, without adverse side effects. Other drug delivery systems may be polymeric backbones which may be, but are not limited to, simple polymers, polymeric carbohydrates, cyclodextrins, heparin or its derivatives, peptides, polymeric beads, etc.
Use and Administration
The betulinic acid derivatives of the invention can be administered to a subject in need thereof to treat the subject by either prophylactically preventing inflammation or relieving it after it has begun. The compounds are preferably administered with a pharmaceutically acceptable carrier, the nature of the carrier differing with the mode of administration, for example, oral administration, usually using a solid carrier and I.V. administration of a liquid salt solution carrier. The formulation of choice can be accomplished using a variety of excipients including, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin cellulose, magnesium carbonate, and the like. Oral compositions may be taken in the form of solutions, suspensions, tablets, pills, capsules, sustained release formulations, or powders. Particularly useful is the administration of the subject ligand molecules directly in transdermal formulations with permeation enhancers such as DMSO. Other topical formulations can be administered to treat dermal inflammation.
A sufficient amount of ligand molecules should be administered to bind to a substantial portion of the ELAM-1 expected to cause or actually causing inflammation so that inflammation can either be prevented or ameliorated. Thus, "treating" as used herein shall mean preventing or ameliorating inflammation and/or symptoms associated with inflammation. Typically, the compositions of the instant invention will contain from less than 1% to about 95% of the active ingredient, preferably about 10% to about 50%. Preferably, between about 10 mg and 50 mg will be administered to a child and between about 50 mg and 1000 mg will be administered to an adult. The frequency of administration will be determined by the care given based on patient responsiveness. Other effective dosages can be readily determined by one of ordinary skill in the art through routine trials establishing dose response curves.
In determining the dose of compounds to be administered, it must be kept in mind that one may not wish to completely block all of the selectin receptors. In order for a normal healing process to proceed, at least some of the white blood cells or neutrophils must be brought into the tissue in the areas where the wound, infection or disease state is occurring. The amount of the compounds administered as blocking agents must be adjusted carefully based on the particular needs of the patient while taking into consideration a variety of factors such as the type of disease that is being treated.
It is believed that the compounds or blocking agents of the present invention can be used to treat a wide range of diseases, including diseases such as rheumatoid arthritis and multiple sclerosis. The compositions of the invention should be applicable to treat any disease state wherein the immune system turns against the body causing the white cells to accumulate in the tissues to the extent that they cause tissue damage, swelling, inflammation and/or pain. The inflammation of rheumatoid arthritis, for example, is created when large numbers of white blood cells quickly enter the joints in the area of disease and attack the surrounding tissues.
Formulations of the present invention might also be administered to prevent the undesirable aftereffects of tissue damage resulting from heart attacks. When a heart attack occurs and the patient has been revived, such as by the application of anticoagulants or thrombolytic (e.g., tPA), the endothelial lining where a clot formed has often suffered damage. When the antithrombotic has removed the clot, the damaged tissue beneath the clot and other damaged tissue in the endothelial lining which has been deprived of oxygen, become activated. The activated endothelial cells then synthesize the ELAM-1 receptors within hours of the cells being damaged. The receptors are extended into the blood vessels where they adhere to glycolipid ligand molecules on the surface of white blood cells. Large numbers of white blood cells are quickly captured and brought into the tissue surrounding the area of activated endothelial cells, resulting in inflammation, swelling and necrosis which thereby decreases the likelihood of survival of the patient.
In addition to treating patients suffering from the trauma resulting from heart attack, patients suffering from actual physical trauma could be treated with formulations of the invention in order to relieve the amount of inflammation and swelling which normally result after an area of the body is subjected to severe trauma. Other disease states which might be treatable using formulations of the invention include various types of arthritis and adult respiratory distress syndrome. After reading the present disclosure, those skilled in the art will recognize other disease states and/or symptoms which might be treated and/or mitigated by the administration of formulations of the present invention.
Other modes of administration will also find use with the subject invention. For instance, the ligand molecules of the invention can be formulated in suppositories and, in some cases, aerosol and intranasal compositions. For suppositories, the vehicle composition will include traditional binders and carriers such as, polyalkylene glycols, or triglycerides. Such suppositories may be formed from mixtures containing the active ingredient in the range of about 0.5% to about 10% (w/w), preferably about 1% to about 2%.
Intranasal formulations will usually include vehicles that neither cause irritation to the nasal mucosa nor significantly disturb ciliary function. Diluents such as water, aqueous saline or other known substances can be employed with the subject invention. The nasal formulations may also contain preservatives such as, but not limited to, chlorobutanol and benzalkonium chloride. A surfactant may be present to enhance absorption of the subject proteins by the nasal mucosa.
The compounds of the instant invention may also be administered as injectables. Typically, injectable compositions are prepared as liquid solutions or suspensions; solid forms suitable for solution in, or suspension in, liquid vehicles prior to injection may also be prepared. The preparation may also be emulsified or the active ingredient encapsulated in liposome vehicles. The compounds of structural formula I can be mixed with compatible, pharmaceutically acceptable excipients.
Suitable vehicles are, for example, water, saline, dextrose, glycerol, ethanol, or the like, and combinations thereof. In addition, if desired, the vehicle may contain minor amounts of auxiliary substances such as wetting or emulsifying agents or pH buffering agents. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in the art. See, e.g., Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., 17th edition, 1985. The composition or formulation to be administered will, in any event, contain a quantity of the ligand molecules adequate to achieve the desired state in the subject being treated.
The various compounds of the present invention can be used by themselves or in combination with pharmaceutically acceptable excipient materials as described above. However, the compounds of the invention can be made as conjugates wherein the compounds of the invention are linked in some manner to a label. By forming such conjugates, the ligand compounds of the invention act as biochemical delivery systems for the label so that a site of inflammation can be detected.
The ligand molecules of the invention could also be used as laboratory probes to test for the presence of a selectin receptor in a sample. Such probes are preferably labeled such as with a radioactive, fluorescent or enzyme activated label.
SYNTHETIC STRATEGY
Throughout this discussion, a standard numbering scheme for the triterpene nucleus will be referred to as described in the Merck Index for betulin (The Merck Index 11: 1212, (1989).
Synthesis of certain of the betulinic acid compounds of the invention requires manipulation about the 3-position of the triterpene nucleus. Some of these manipulations involve a double inversion methodology about this center.
The compound can be inverted from the β- to the α- form i.e. the C 3 -β-OH to the C 3 -α-OH using the Mitsunobu method (Mitsunobu, O. Synthesis (1981), 1) followed by use of the carbon glycosidation procedures described herein.
Other manipulations can be performed on, but not limited to, the C28 carboxylic acid such as, monovalent or polyvalent attachment to amine functionalities of a drug, linker or polymeric backbone; reduction of the carboxylic acid to the alcohol using standard conditions with subsequent manipulation of the resultant alcohol such as, replacement of the alcohol functionality for a halide, amine, sulfide or other general functional group using standard conditions; oxidation of the resultant alcohol to the aldehyde which can be further functionalized such as, reductive amination to amines, polyamines, polymer supported amines or Wittig methodologies; and glycosidations of the resultant alcohol or carbono-glycosidation conditions as shown in this document or amines with mono-, di-, tri- or oligosaccharides. In general, standard methodologies may be used to transform the C28 carboxylic acid group to other useful functionalities or derivatives.
In some instances, a benzyl ester protecting group can be used for the protection of the E-ring carboxyl group. Subsequent removal will also provide reduction of the C20-29 olefin function to afford C19 isopropyl betulinic acid conjugates.
Other manipulations can be performed on, but not limited to, the C19 exocyclic olefin (that is the C20-29 olefin) in which the olefin can be converted under standard conditions such as, osmium tetroxide methodologies, to a diol which can be subsequently oxidized to the C20 ketone using standard conditions with sodium periodate in methanol. Other manipulations can include diol formation with subsequent glycosidation with mono-, di-, tri- or oligosaccharides. The olefin can be reacted with a variety of hydroborating agents under standard conditions for the formation of a terminal alcohol which can be oxidized to an aldehyde or carboxylic acid for the introduction of other functional groups under standard conditions. The resultant C20 ketone can be reduced to the R or S alcohol configuration using alpine borane conditions (see: Aldrichimica Acta 15(3), 68 (1982)); treated with Wittig or stabilized Wittig reagents under standard conditions for the placement of other desired functional groups; reductive aminations or reduction with subsequent glycosidation or carbon-glycosidation under standard conditions or carbon-glycosidation conditions as shown in this document.
Other Synthetic Aspects
The synthesis of other compounds containing alternate carbohydrates attached to the carbon linking arms for the glycoside conjugates are accomplished by usual glycosidation methods. Alternately, any carbohydrate unit being charged or uncharged and/or desoxygenated species can be formed using the carbon-glycosidation procedure given in this disclosure, but this disclosure does not exclude the analogs prepared from branched, linear or other forms of di-, tri- and poly saccharides or oligosaccharides or combinations. The derivatized carbon-glycoside can be further utilized as a linking group between a pyran ring and the spacer attached to the betulinic acid nucleus by a selective protection methodology involving use of a 2'3'-benzylidene derivative (see Example 4) in which selective rearrangement and/or functionalization and/or glycosidation can be accomplished prior to deprotection. Thus, the various derivatives are converted to potentially more useful compounds.
Multivalent Forms of the Receptor Binding Compounds
The affinity of the compounds of the invention for a receptor can be enhanced by providing multiple copies of the ligand in close proximity, preferably using a scaffolding provided by a carrier moiety. It has been shown that provision of such multiple valence with optimal spacing between the moieties dramatically improves binding to a receptor. (See, for example, Lee, Y. C. et al., Biochem 23: 4255 (1984)).
The multivalency and spacing can be controlled by selection of a suitable carrier moiety. Such moieties include but are not limited to molecular supports which contain a multiplicity of functional groups that can be reacted with functional groups associated with the compounds of the invention. A particularly preferred approach involves coupling of the compounds of the invention to amino groups of the carrier through reductive amination. Reductive amination is a particularly convenient way to couple aldehyde moieties to free amino groups by first forming the Schiff base and then treating the conjugate with a reducing agent, such as a hydride reducing agent. Typically, the amino group-bearing carrier is mixed with the carbohydrate moiety at about pH 9 and allowed to form the Schiff base; the solvents are typically evaporated and a reducing agent is added at high pH to complete the reaction.
Particularly convenient carrier moieties to obtain multivalent forms of the invention compounds include (amines (e.g. N(CH 2 CH 2 NH 2 ) 3 ), proteins and peptides, particularly those containing lysyl residues which have ω-amino groups available for binding. It is also useful to include in the peptide or protein at least one tyrosine residue, as this offers a convenient site for labeling, for example with radioactive iodine. A particularly convenient carrier to obtain a trivalent couple is the peptide Lys-Tyr-Lys. Complete reaction of the compounds of the invention with the free amino groups on this peptide result in a trivalent moiety. Thus, compounds of the invention of the general formula (I) may be used to make multivalent constructs: ##STR5##
Attachments of the ligand to the amine, or vice versa, by reductive amination would produce multivalent compounds. Preferred attachment points would be at the C28 carbonyl at Y, R3, R4, R5, R6, and W, and particularly at positions C28 carbonyl, R3, R5, R6 and W.
Of course, a variety of carriers can be used, including proteins such as BSA or HSA, a multiplicity of peptides including, for example, pentapeptides, decapeptides, pentadecapeptides, and the like. Preferably, the peptides or proteins contain the desired number of amino acid residues having free amino groups in their side chains; however, other functional groups, such as sulfhydryl groups or hydroxyl groups can also be used to obtain stable linkages. For example, the carbohydrate compounds of the invention may be oxidized to contain carboxyl groups which can then be derivatized with either free amino groups to form amides or with hydroxyl groups to form esters. In addition, a suitably functionalized biotin tether may be attached with subsequent complexation with avidin for mulitvalent forms. ##STR6##
The structure of formula (I) above may be in different isomeric forms and such are encompassed by this disclosure. In particular, the carbon glycoside moiety may be in either the alpha or beta configuration and the linkage by which any sugar is attached at the A-Ring C-3 position may be either axial or equatorial. For instance, acetates and benzoates may serve as protecting groups for the hydroxyl groups in sugars and display neighboring group participation in glycosidation reactions. Thus, by judicious choice of protecting groups prior to the glycosidation, i.e., benzyl ethers, acetates or benzoates, one can preferentially select for either the alpha- or beta- carbon linked glycosides (H. Paulsen, Angew Chem. Int. Ed. Engl., 21: 155 (1982); R. R. Schmidt, "Synthesis of Carbon linked glycosides in Comprehensive Organic Synthesis", Ed. B. M. Trost, 6:33-64). Thus, here and throughout the different stereo configurations are not shown but are understood to be encompassed by this disclosure and the appended claims.
EXAMPLES
The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make the compounds and compositions of the invention and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers that would be used (e.g., amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, molecular weight is weight average molecular weight, temperature is in degrees centigrade and pressure is at or near atmospheric.
General
Reagents were purchased from commercial suppliers such as Aldrich Chemical Company or Lancaster Synthesis Ltd. and were used without further purification unless otherwise indicated. Tetrahydrofuran (THF) and dimethylforamide (DMF) were purchased from Aldrich in sure seal bottles and used as received. All solvents were purified by using normal methods unless otherwise indicated. Reactions were done under a positive pressure of nitrogen or with a drying tube, at ambient temperature (unless otherwise stated), in anhydrous solvents, and the reaction flasks were fitted with rubber septa for the introduction of substrates and reagents via syringe. Glassware was oven dried and/or heat dried prior to use. Analytical thin layer chromatography (tlc) was performed on glass-backed silica gel 60 F 254 plates (Analtech, 0.25 mm) and eluted with the appropiate solvent ratios (v/v) and are denoted where appropiate. The reactions were assayed by tic and terminated as judged by the consumption of starting material.
Visualization of the tic plates was done with a p-anisaldehyde spray reagent or phosphomolybdic acid reagent (Aldrich Chemical 20% wt in ethanol) and activated with heat.
Work-ups were typically done by doubling the reaction volume with the reaction solvent or extraction solvent and then washing with the indicated aqueous solutions using 25% by volume of the extraction volume unless otherwise indicated.
Product solutions were dried over Na 2 SO 4 prior to filtration and evaporation of the solvents under reduced pressure on a rotary evaporator and noted as solvents removed in vacuo.
Plug filtration refers to using a weight ratio of 10:1 of silica gel to crude product and eluting with a solvent to remove salts and baseline impurities.
Flash column chromatography (Still, W. C.; Kahn, M.; Mitra, A. J. Org. Chem., 43: 2923, (1978) was performed using Baker grade flash silica gel (47-61 mm) and a weight ratio of 20-50 to 1 unless otherwise stated.
1 H-NMR spectra were recorded on a Varian 300 instrument operating at 300 MHz and 13 C-NMR spectra were recorded on a Varian 300 instrument operating at 75 MHz. NMR spectra were obtained as CDCl 3 solutions (reported in ppm), using chloroform as the reference standard (7.25 ppm and 77.00 ppm) or CD 3 OD (3.4 and 4.8 ppm and 49.3 ppm), or as a mixed NMR solvent mixture when necessary, or internally tetramethylsilane (0.00 ppm) when appropiate. For Peak multiplicities, the following abbreviations are used: s (singlet), d (doublet), t (triplet), m (multiplet), br (broadened), dd (doublet of doublets), dt (doublet of triplets). Coupling constants, in Hertz.
Infrared spectra were recorded on a Perkin-Elmer FT-IR spectrometer as neat oils, or as CDCl 3 solutions, and are reported in wave numbers (cm -1 ). The mass spectra were obtained using FAB.
The yields indicated are yields of isolated products purified by flash chromatography and having a purity of greater than 95% as indicated by TLC and 300 MHz 1 H-NMR.
Example 1
Preparation of 2-Chloromethyl-3-(tri-O-benzyl-α-L-C-fucopyranoside)-1-propene (1) ##STR7##
To a solution of tri-O-benzyl-L-fucopyranose (20.0 g, 46.03 mmole, 1.00 mmole equiv.) in anhydrous acetonitrile (200 mL) at 0° C. was added 2-chloromethyl-3-trimethylsilyl-1-propene (30.0 g, 184.34 mmole, 4.00 mmole equiv.). Trimethylsilane trifluoromethane sulfonic acid (10.24 g, 46.03 mmol, 1.00 mmole equiv.) was added dropwise in anhydrous acetonitrile (30 mL, overall reaction concentration 0.2M) and the reaction contents stirred at 0° C. for 30 minutes. After 30 minutes, the reaction was dituted with ethyl acetate (230 mL) and the reaction was terminated by pouring the contents slowly into aqueous saturated sodium bicarbonate. The heterogeneous layers were separated and the organic phase was washed twice with portions of water, 1.0M hydrochloric acid and brine. The crude product was dried over anhydrous sodium sulfate, filtered and plugged through a small pad of silica gel. The solvent was removed in vacuo which afforded an oil that was chromatographed on Baker grade flash silica gel (47-61 mm) (ratio of 50 to 1) and eluted with 5 or 10% ethyl acetate in hexanes. Concentration in vacuo afforded 20.01 g of 2-Chloromethyl-3-(tri-O-benzyl-α-L-C-fucopyranoside)-1-propene (1) (85%).
Example 2
Preparation of 2-(Tri-O-benzyl-α-L-C-methylfucopyranose)-3-[3-O-(betulinic acid)]-1-propene (2) ##STR8##
To a solution of sodium hydride (126 mg, 5.25 mmole, 6.00 mmole equiv.) in anhydrous 25% dimethylformamide in tetrahydrofuran (5.5 mL) at ambient temperature was added betulinic acid (0.40 g, 0.876 mmol, 1.00 mmole equiv.) in a minimum amount of anhydrous 25% dimethylformamide in tetrahydrofuran. Sodium iodide (1.31 g, 8.76 mmole, 10.00 mmole equv.) and Tetra-n-butylammonium Iodide (32.4 mg, 0.0876 mmole, 0.10 mmole equiv.) were added and the reaction contents were warmed to a gentle reflux (until the evolution of H 2 ceased) for 30 minutes. 2-Chloromethyl-3-(tri-O-benzyl-α-L-C-fucopyranoside)-1-propene (1) (1.0 g, 1.97 mmole, 2.30 mmole equiv.) was added dropwise in anhydrous 25% dimethylformamide in tetrahydrofuran (5.5 mL, total of 0.08M) and gently refluxed for 6 hours. After 6 hours at reflux, the reaction was terminated by the careful addition of 50% methanol in toluene (2 mL) at 0° C. and then 4M hydrochloric acid until the pH was 1-2 and then diluted with ethyl acetate. The heterogeneous layers were separated and the organic phase was washed with portions of 1.0M hydrochloric acid, sodium bicarbonate and brine. The crude product was dried over anhydrous sodium sulfate, filtered and plugged through a small pad of silica gel eluting with ethyl acetate. The solvent was removed in vacuo which afforded an oil that was chromatographed on Baker grade flash silica gel (47-61 mm) (ratio 50 to 1) and eluted with benzene, 10% ethyl acetate in hexane, 30% ethyl acetate in hexane, 50% ethyl acetate in hexane and finally with 5% methanol in chloroform. Concentration in vacuo afforded 0.440 g of 2-(tri-O-benzyl-α-L-C-methylfucopyranose)-3-[3-O-(betulinic acid)]-1-propene (2) (67%) as a white foam powder.
Alternate Procedure
2-(Tri-O-benzyl-α-L-C-methylfucopyranose)-3-[3-O-(betulinic acid)]-1-propene (2) may also be prepared by the following procedure.
To a solution of sodium hydride (126 mg, 5.25 mmole, 6.00 mmole equiv.) in anhydrous benzene (5.5 mL) at ambient temperature is added betulinic acid (0.40 g, 0.876 mmol, 1.00. mmole equiv.) dropwise in a minimum amount of anhydrous tetrahydrofuran. Sodium iodide (1.31 g, 8.76 mmole, 10.00 mmole equv.) and Tetra-n-butylammonium Iodide (32.4 mg, 0.0876 mmole, 0.10 mmole equiv.) are added and the reaction contents are warmed to a gentle reflux (until the evolution of H 2 ceased) for 30 minutes. 2-Chloromethyl-3-(tri-O-benzyl-α-L-C-fucopyranoside)-1-propene (1) (1.0 g, 1.97 mmole, 2.30 mmole equiv.) is added dropwise in anhydrous tetrahydrofuran (5.5 mL, total reaction concentration of 0.08M) and gently refluxed for 6 hours. After 6 hours at reflux, the reaction is terminated by the careful addition of 50% methanol in toluene (2 mL) at 0° C. and then 4M hydrochloric acid until the pH is 1-2 and the reaction contents are diluted with ethyl acetate. The heterogeneous layers are separated and the organic phase is washed twice with portions of 1.0M hydrochloric acid, saturated sodium thiosulfite and brine. The crude product is dried over anhydrous sodium sulfate, filtered and plugged through a small pad of silica gel and eluted with ethyl acetate. The solvent is removed in vacuo which afforded an oil that is chromatographed on Baker grade flash silica gel (47-61 mm) (ratio 50 to 1) and eluted with 10% ethyl acetate in hexane, 50% ethyl acetate in hexane, 100% ethyl acetate. Concentration in vacuo afforded 2-(tri-O-benzyl-α-L-C-methylfucopyranose)-3-[3-O-(betulinic acid)]-1-propene (2) as a white foam powder.
Example 3
Preparation of 1-[3-O-(betulinic acid)]-2-(α-L-C-methylfucopyranose)-propane (3) ##STR9##
A solution of 2-(tri-O-benzyl-α-L-C-methylfucopyranose)-3-[3-O-(betulinic acid)]-1-propene (2) (300 mg, 0.323 mmole, 1.00 mmole equiv.) in 10% acetic acid in methanol (ethyl acetate can be added to enhance solubility) (1.6 mL), was added to 10% palladium on carbon (35 mg per mmole of substrate) and placed on a parr hydrogenation apparatus. The reaction vessel was evacuated and re-filled with hydrogen thrice and then shaken at 50 PSI for 48 hours. The reaction was terminated by filtering the contents through Celite to remove the catalyst. The reaction mixture was concentrated in vacuo and washed with dichloromethane to give a white powder to afforded 131.7 mg of 1-[3-O-(betulinic acid)]-2-(α-L-C-methylfucopyranose)-propane (3) (62%).
Example 4
Preparation of 1-[3-O-(Betulinic acid-27,29-diol)]-2-(tri-O-benzyl-α-L-C-methylfucopyranose)-2',3'-propanediol (4) ##STR10##
To a solution of 2-(tri-O-benzyl-α-L-C-methylfucopyranose)-3-[3-O-(betulinic acid)]-1-propene (2) (1.00 g, 1.06 mmole, 1.00 mmole equiv.) in anhydrous dichloromethane (5.3 mL, 0.2M) at ambient temperature is added osmium tetroxide (0.0106 mmole, 21.2 mL of a 0.5M solution in toluene, 0.01 mmole equiv.) and N-methylmorpholine-N-oxide (1.24 g, 10.6 mmole, 10.00 mmole eqiv.). The reaction contents are stirred at ambient temperature for 6 days and the reaction is terminated by the addition of 25% aqueous sodium metasulfite and stirred for 1 hour. The heterogeneous layers are separated and the organic phase is washed twice with portions of 25% aqueous sodium metasulfite, 1.0M hydrochloric acid, sodium bicarbonate and brine. The crude product is dried over anhydrous sodium sulfate, filtered and plugged through a small pad of silica gel with ethyl acetate. The solvent is removed in vacuo which affords an oil that is chromatographed on Baker grade flash silica gel (47-61 mm) (ration of 50 to 1) and eluted with 50% ethyl acetate in hexane and then 5% methanol in chloroform. Concentration in vacuo affords 1-[3-O-(betulinic acid-27,29-diol)]-2-(tri-O-benzyl-α-L-C-methylfucopyranose)-2',3'-propanediol (4).
Example 5
Preparation of 1-[3-O-(Betulinic acid-27,29-diol)]-2-(α-L-C-methyl-fucopyranose)-2', 3'-propanediol (5) ##STR11##
A solution of 1-[3-O-(betulinic acid-27,29-diol)]-2-(tri-O-benzyl-α-L-C-methylfucopyranose)-2',3'-propanediol (4) (2.00 g, 2.02 mmole, 1.00 mmole equiv.) in 10% acetic acid in methanol (10 mL, 0.2M), was added to 10% palladium on carbon (35 mg per mmole of substrate wetted with toluene) and the contents placed on a parr hydrogenation apparatus. The reaction vessel is evacuated and re-filled with hydrogen thrice and then shaken at 50 PSI for 48 hours. The reaction is terminated by filtering the contents through Celite to remove the catalyst. Concentration in vacuo affords a white powder which is filtered and rinsed with dichloromethane to give 1-[3-O-(betulinic acid-27,29-diol)]-2-(α-L-C-methylfucopyranose)-2',3'-propanediol (5).
A further manipulation of a glycerol linking arm is necessary to give a 3'-O-glycosylated derivative. This can be accomplished by using the partial protection method developed by Garegg and Hultberg [Garegg, P. J., Hultberg, H., Carbo. Res. 93 (1981) C10-C11.] involving reductive ring opening of a 2',3'-benzylidene acetal with sodium cyanoborohydride in THF.
Example 6
Preparation of 1-[3-O-(27-Oxo-betulinic acid)]-2-(α-L-C-methylfucopyranose)-2'-oxo-ethane tri-sulfate (6) ##STR12##
To a solution of 1-[3-O-(27-oxo-betulinic acid)]-2-(α-L-C-methylfucopyranose)-2'-oxo-ethane (8) (50 mg, 75.8 mmole, 1.00 mmole equiv.) in anhydrous dimethylformamide (3.5 mL, 0.2M) at ambient temperature is added sulfur trioxide pyridine complex (758 mmole, 10 mmole equiv.) polymer. Graf, W. Chem. Ind. 232 (1987). The reaction contents are stirred at ambient temperature and then warmed to a gentle reflux for 8 hours. The reaction is terminated by cooling to ambient temperature, neutralization with excess NaHCO 3 and filtering the polymer through celite. The solvent is removed in vacuo which affords an oil that is azeotrophed with toluene. Concentration in vacuo affords 1-[3-O-(27-oxo-betulinic acid)]-2-(α-L-C-methylfucopyranose)-2'-oxo-ethane tri-sulfate (6).
Alternate Procedure
1-[3-O-(27-Oxo-betulinic acid)]-2-(α-L-C-methylfucopyranose)-2'-oxo-ethane tri-sulfate (6) may also be prepared by the following procedure
To a solution of 1-[3-O-(27-oxo-betulinic acid)]-2-(α-L-C-methylfucopyranose)-2'-oxo-ethane (8) (50 mg, 75.8 mmole, 1.00 mmole equiv.) in anhydrous dimethylformamide (3.5 mL, 0.2M) at ambient temperature is added sulfur trioxide pyridine complex (758 mmole, 10 mmole equiv.). The reaction contents are stirred at ambient temperature and then warmed to a gentle reflux for 8 hours. The reaction is terminated by cooling to ambient temperature, neutralization with excess NaHCO 3 and filtering through celite. The solvent is removed in vacuo which affords an oil that is azeotrophed with toluene. Concentration in vacuo affords 1-[3-O-(27-oxo-betulinic acid)]-2-(α-L-C-methylfucopyranose)-2'-oxo-ethane trisulfate (6).
Example 7
Preparation of 1-[3-O-(27-Oxo-betulinic acid)]-2-(tri-O-benzyl-α-L-C-methylfucopyranose)-2'-oxo-ethane (7) ##STR13##
To a solution of 2-(tri-O-benzyl-α-L-C-methylfucopyranose)-3-[3-O-(betulinic acid)]-1-propene (2) (40 mg, 0.043 mmole, 1.00 mmole equiv.) in anhydrous dichloromethane (0.210 mL, 0.2M) at -78° C. is added excess ozone. The reaction contents are stirred at -78° C. for 1 hour and the reaction is terminated by the addition of dimethylsulfide (26.9 mg, 31.7 mL, 0.431 mmole, 10.00 mmole equiv.) and stirred for 1 hour and allowed to warm to ambient temperature. Water is added and the heterogeneous layers are separated and the organic phase is washed twice with portions of 1.0M hydrochloric acid, sodium bicarbonate and brine. The crude product is dried over anhydrous sodium sulfate, filtered and plugged through a small pad of silica gel of a weight ratio of 10:1. The solvent is removed in vacuo which affords an oil that is chromatographed on Baker grade flash silica gel (47-61 mm) (ratio of 50 to 1) and eluted with 50% ethyl acetate in hexane. Concentration in vacuo affords 1-[3-O-(27-oxo-betulinic acid)]-2-(tri-O-benzyl-α-L-C-methylfucopyranose)-2'-oxo-ethane (7).
Example 8
Preparation of 1-[3-O-(27-Oxo-betulinic acid)]-2-(α-L-C-methylfucopyranose)-2'-oxo-ethane (8) ##STR14##
A solution of 1-[3-O-(betulinic acid)]-2-oxo-2-(tri-O-benzyl-α-L-C-methylfucopyranose)-ethane (7) (15 mg, 0.0159 mmole, 1.00 mmole equiv.) in 10% acetic acid in methanol (ethyl acetate can be added to enhance solubility) (1.5 mL), is added to 5% palladium on carbon (35 mg per mmole of substrate) and placed on a parr hydrogenation apparatus. The reaction vessel is evacuated and re-filled with hydrogen thrice and then shaken at 50 PSI for 48 hours. The reaction is terminated by filtering the contents through Celite to remove the catalyst. The reaction mixture is concentrated in vacuo and washed with dichloromethane to give 1-[3-O-(27-oxo-betulinic acid)]-2-(α-L-C-methylfucopyranose)-2'-oxo-ethane (8).
Example 9
Anti-inflammatory Effects
Using the arachidonic acid (AA), murine skin inflammation model, described by Harris, R. R. et al. (Skin Pharmacol 3: 29-40 (1990)) the anti-inflammatory activity of 1-[3-O-(betulinic acid)]-2-(α-L-C-methylfucopyranose) propane (3) was tested. For comparison, betulinic acid was also tested. All compounds were dissolved at 50 mg/mL in CHCl 3 :CH 3 OH (1:1) and 10 mL of each compound was applied two times to the ear, at about a 2 minute interval or the period of time it took for the solvent to evaporate from the ear, immediately following arachidonic acid (AA). A control of AA alone was run. Ninety minutes later a 6 mm disk of each ear was removed and weighed. In three separate experiments, as shown in Table 1, it was observed that the percent inhibition of swelling caused by AA alone was reduced by about 36.7%, 46.6%, and 59% for the 1-[3-O-(betulinic acid)]-2-(α-L-C-methylfucopyranose)-propane (3) and 0%, 12.2%, and 25.9% for betulinic acid.
These results clearly establish that the betulinic acid derivatives of the invention have medical utility for the treatment of inflammation. In all three experiments the betulinic acid derivative inhibited the inflammatory response. Moreover, it should be noted that these effects were observed at a lower concentration, 1.5 μmoles, than the effects observed for betulinic acid which was used at 2.2 μmoles.
TABLE 1______________________________________Anti-Inflammatory ActivitiesTopical Administration in Arachidonic Acid Ear Model. Amount AppliedCompound % Inhibition of Swelling in mg (mmoles)______________________________________Betulinic acid 0.0%, 12.2%, 25.9% 1 mg (2.2 mmoles)Compound (3) 36.7%, 46.6%, 59% 1 mg (1.5 mmoles)______________________________________
Example 10
Inhibition of Leukotriene Biosynthetic Enzymes
Several assays can be performed to assess the inhibitory activity of the invention compounds against enzymes involved in leukotriene biosynthesis. Assays for 5-lipoxygenase are known in the art and can be readily performed as described by Shimuzu, T., et al., Proc. Natl. Acad. Sci. USA 81: 693-698, (1984) and Epan, R., et al., J. Biol. Chem. 260: 11554-11559 (1985).
The compounds of the instant invention were assayed for their capacity to inhibit 5-lipoxygenase as now described using a crude enzyme preparation from rat basophilic leukemia cells (RBL-1) (Shimuzu, T., Radmark, O. and Samuelsson, B. Proc. Natl. Acad. Sci. USA 81: 698-693 (1984) and Egan, R. W. and Gale, P. H. J. Biol. Chem. 260: 11554-11559) (1985).
Test compounds are pre-incubated with the enzyme for 5 minutes at room temperature and the reaction is initiated by addition of substrate, linoleic acid. Following an 8 minute incubation at room temperature, the reaction is terminated by addition of NaOH, and absorbance read at 234 nm to determine levels of 5-HETE. Compounds are screened at 50 μM.
Example 11
Anti-Metastatic Activity
Experiments were conducted to determine the capacity of the invention compounds to interfere with the binding of cancer cells to E-selectin. The compounds are dissolved in dimethylformamide (DMF) prior to being assayed. The assay consists of combining the appropriate test compound, E-selectin chimera which contains an IgG tail, a detection system consisting of biotinylated anti-human Ig (Fc specific), and streptavidin-alkaline phosphatase all in 10 mM Tris, 150 mM NaCl, pH 7.2-7.4, plus 1 mM Ca ++ . The mixture is rotated briskly on a rotary platform at room temperature for 30-60 minutes. Particulate matter is removed by centrifugation, and the soluble fraction is transferred onto 96-well microtiter plates containing glutaraldehyde fixed LS174T colon carcinoma cells. After 60 minutes at 37° C., plates are washed and E-selectin chimera bound to cells is quantified by addition of pNPP substrate in 1M diethanolamine buffer containing 0.1 mg/ml MgCl 2 at pH 9.8. Plates are developed in the dark and read at 405 nm. The IC 50 values are the lowest concentrations from serial two-fold dilutions (quadruplicate wells at each concentration) which inhibits by 50% or more relative to the control. DMF (vehicle) typically has no effect. It will be appreciated that both betulinic acid and compound (3) significantly interfere with cancer cell binding to E-selectin binding. The results from two experiments are shown in FIGS. 3 and 4. The IC 50 values for compound (3) (30 μm) are lower than for betulinic acid (60 μm). These findings support the suitability of compound (3) for the treatment or prevention of certain forms of metastatic cancers. Moreover, these findings further stress the enhanced multi-medicament activities of the invention compounds.
Example 12
Inhibition of P-Selectin Binding
Certain of the invention compounds were tested for their capacity to inhibit P-selectin binding to HL-60 cells, and to a chemical known to bind to P-selectin, 2,3 sLex. The following materials and procedures were used.
Compound Preparation
Compound (3) of Example 3 and betulinic acid were solubilized in DMF to yield 100 mM solutions.
P-Selectin Detection Solutions. Goat F(ab')2 anti-human IgG (Fc spec.)-biotin and streptavidin-AP were diluted 1:1000 in 1% BSA-TBS with 1 mM Ca ++ . An Elisa assay was utilized to measure P-selectin binding to 2,3 sLex, and P-selectin was added at 300 ng/ml. An Elisa assay was also used to assay for the capacity of the invention compounds to inhibit HL-60 cell binding to P-selectin. HL-60 cells were used, and P-selectin was added at 200 ng/ml.
Plate Preparation
2,3 sLex was coated at 30 pmoles/well to Probind microtiter plates for Elisa. The glycolipid was added at 50 μl/well in 50% MeOH and allowed to evaporate overnight. Elisa plates and HL-60 assay plates were blocked with 5% BSA-TBS Ca ++ for more than an hour at room temperature. The plates were washed with TBS without Ca ++ .
Cell Preparation
HL-60 cells were harvested by centrifugation, washed with TBS no Ca ++ , counted, and the density adjusted to 2×10 6 /ml in 1% BSA-TBS Ca ++ .
Assay
Briefly, the assays were conducted as follows. Compound (3) and betulinic acid were added to P-selectin detection solutions at 4, 2, 1, 0.5, 0.25 and 0.125 mM for the HL-60 based assay, and at 2, 1, 0.5, 0.25, 0.125 and 0.063 mM for the assay involving 2,3 sLex. DMF solutions were added directly to 1% BSA/TBS-Ca for dilutions through 0.5 mM. Lower concentrations were made in serial two-fold dilutions in BSA-TBS. These solutions were incubated at room temperature on a rotating platform for 1 hour, centrifuged to pellet particulate matter, and then added in triplicate for 2,3 sLex coated plates, or quadruplicate for HL-60 cells at 50 μl/well. An equal volume of HL-60 cells was added to wells for the cell based assay. The 2,3 sLex coated plates were incubated at 37° C. for 45 minutes, washed 3× with TBS, and 50 μl of substrate added to each well. Plates with HL-60 cells were incubated at 4° C. for 1 hour, the cells pelleted by centrifugation and washed 3× with TBS. For both assays, substrate was added at 75 μl/well. After color developed to an appropriate intensity, 50 μl/well was transferred to another plate for O.D. determination at 405 nm. FIG. 5 shows the results. Compound (3) did inhibit P-selectin binding to sLex, and it was somewhat more effective than betulinic acid.
The results established that the IC 50 for inhibiting P-selectin binding to 2,3 sLex for betulinic acid was about 125 μM; for compound (3) it was <1 and >0.5 mM. The HL-60 assay showed that betulinic acid interfered with P-selectin binding to HL-60 cells in a dose dependent way. The IC 50 was about 0.75 mM. Compound (3) also interfered with P-selecting binding to HL-60 cells in a dose dependent manner, but was again less effective than betulinic acid. The IC 50 was about 2 mM.
These results confirm and extend those presented in Examples 9-11 in that the invention compounds have a marked and significant multi-medicament capacity, and can interfere with selectin binding generally, as shown here relating to P-selectin, and in Example 11 to E-selectin. Importantly, the invention compounds interfere with the binding of human HL-60 cells to both P-selectin and E-selectin.
The instant invention is shown and described herein in what is considered to be the most practical, and preferred embodiments. It is recognized, however, that departures may be made therefrom which are within the scope of the invention, and that obvious modifications will occur to one skilled in the art upon reading this disclosure.
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This invention relates generally to the field of medicinal chemistry, and more specifically to derivatives of a subclass of triterpenoid acids that have multi-medicament properties, that is derivatives of the lupane, betulinic acid, formulations containing such, and their use to prevent or treat certain diseases, and preferably to derivatives or analogues of betulinic acid, that have the following structural formula (1): ##STR1## wherein: Y is OR 1 , NR 1 2 , O - M 1 ;
R 1 is H, LOWER ALKYL,
M 1 is Na + , K + , Mg ++ , Ca ++ ions;
each R 2 is independently CH 2 OR 1 or CH 3 ;
each R 3 is independently H, CH 3 , lower alkyl, COY, CH 2 OH, CH 2 OCH 2 CH=CH 2 , CH 2 OSO 3 - M 1 ;
each Z is independently NHR 1 2 , NR 1 Ac, NR 1 Bz, H, OCH 3 , lower alkyl, OH, OSO 3 - M 1 , OCH 2 CH=CH 2 , OCH 2 CO 2 H or O-glucoside;
each X is independently O, S, NR 1 or NR 2 1
each W is independently C=O, C=CR 1 2 , CR 1 CR 1 3 , CR 1 -CR 1 2 OR 1 , COR 1 -CR 1 OR 1 , COR 1 CR 1 2 OR 1 , CR 1 CR 1 2 NR 1 2 , CR 1 CR 1 2 OCR 1 COY, CHR 4 ;
R 4 is H, OH, OSO 3 - M 1 , or NH(CH 2 )nNH 2 , where n=1-8, or NH-Ph-NH 2 where Ph=an phenyl or naphthyl rings substituted with up to 3 amine functionalities and the remaining substitutions can be H, R 1 , R 2 or COY;
R 5 and R 6 are independently H, CH 3 , or taken together form a 5 or 6 membered carbocyclic ring.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an apparatus and method for non-invasively measuring aortic blood flow in a patient. More particularly, the invention relates to an apparatus and method for determining aortic blood flow by measuring the pressure differential between the left and right subclavian arteries.
2. Description of the Related Art
In a conventional flow apparatus and method, aortic blood flow is measured by one of several techniques that involve injection of a "bolus" of foreign material into the ventricle of the heart or into the aorta. The movement of the "bolus" is then monitored by thermal or nuclear (x-ray, gamma ray) sensors. All of these techniques have the severe disadvantage of being invasive. The foreign material injected is usually harmless, but some patients may have adverse reactions to it. These procedures usually must be performed in a "cath lab", which is a relatively expensive facility. This, in addition to the need for the services of a skilled cardiologist, make these procedures relatively expensive.
An alternative conventional apparatus and method uses ultrasonic imaging techniques to measure the blood flow velocity profile in the aorta. Total volumetric blood flow can be found by integration of the velocity profile. However, this method is very sensitive to movement artifacts. The equipment is also too large and sensitive to movements to be used on an ambulatory patient, or during surgery. The equipment is also relatively expensive.
SUMMARY OF THE INVENTION
A general object of the invention is to provide an improved method and apparatus for non-invasive measurement of blood flow in the aorta.
A second object is to provide simultaneous, non-invasive measurement of aortic blood flow and blood pressure.
A third object is to provide a non-invasive measurement of cardiac output.
A fourth object is to provide a method and an apparatus to accomplish the above objects more cost-effectively than conventional methods and apparatuses.
A fifth object is to provide a method and an apparatus to accomplish the above objects which is more resistant to movement artifacts.
A sixth object is to provide an improved method and apparatus for measurement of blood pressure, cardiac output, and other cardiovascular parameters during an exercise stress test.
A seventh object is to measure cardiac output with an apparatus that is practical for routine use in clinical anesthesia.
The present invention overcomes several shortcomings of conventional aortic blood flow measurement apparatuses and methods. It is completely non-invasive. The apparatus is relatively small, lightweight, and inexpensive. The apparatus comprises one small sensor attached to each of the patient's wrists. No sensors are placed on or near the patient's chest. Thus, the method and apparatus of the present invention may be used during thoracic surgery and heart massage to monitor cardiac output in real time.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments will be described with reference to the drawings, in which the elements have been denoted by like reference numerals throughout the figures, and in which:
FIG. 1 is a ventral view of an aorta;
FIG. 2 is a schematic view of the apparatus of the present invention;
FIG. 3 is a schematic view of the offset correction means; and
FIG. 4 is a graph showing the pressure/flow relationship.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The anatomy of the aortic arch 10 and, in particular, of the subclavian arteries 11 and 12, is shown in FIG. 1. Blood ejected by the left ventricle of the heart enters the arch at its proximate end 13. Blood destined for the legs and torso exits the arch at its distal end 14. As shown in this illustration, the right subclavian artery is located on the aortic arch 10 about 2 or 3 cm "upstream" of the left subclavian artery 12. This 2-cm section of the aorta, together with the two subclavian arteries, can be used to form a capillary-(or orifice-) type flowmeter.
Specifically, the subclavian artery pressures are measured indirectly by means of arterial blood pressure sensors placed on arteries of the arms 22 of a patient 20, as shown in FIG. 2. The brachial arteries, radial arteries, ulnar arteries or even finger arteries can be used. Likewise, any known blood pressure sensor can be used. However, in the preferred embodiment, a tonometer-type blood pressure sensor 24 is applied to the radial artery of each arm 22.
The difference between the two subclavian artery pressures is directly related to the instantaneous blood flow in the aortic arch 10. Thus, the aortic arch 10 is used as the flow-to-pressure transducer of a capillary-type flowmeter. It is arguable that the configuration is more similar to an orifice-type flowmeter. However, this is merely a semantic distinction.
FIG. 2 shows the preferred embodiment of the apparatus of the present invention for aortic blood flow measurement in schematic form. As shown in FIG. 2, an arterial tonometer blood pressure sensor 24 is applied to each wrist of the patient 20 to measure pressure in the left and right radial arteries. A blood pressure cuff (not shown) may optionally be used on one or both of the patient's arms 22 for determination of coefficients to be used in signal processing software of the tonometry system, emergency blood pressure measurements, and other purposes. The apparatus of the preferred embodiment includes two sensor control means 26. Each sensor control means 26 typically comprises one or more microprocessors and "DSP chips" and is connected to one tonometer sensor 24. Each sensor control means 26 processes the sensor signals, positions the sensor 24, adjusts the hold-down pressure (HDP) of the sensor 24 against the patient's wrist, applies calibration (if any) to the sensor signals, and outputs a signal 26a representing the instantaneous blood pressure in one of the radial arteries. These are functions used in arterial tonometry and are shown, for example in U.S. Pat. Nos. 4,836,213 and 4,987,900.
Each radial arterial blood pressure signal is subjected to further processing prior to final display, as shown in FIG. 2. First, each blood pressure signal 26a is output by one of the sensor control means 26 to a corresponding equalization device 28. Each equalization device 28 models the inverse of the transfer function between the pressure at the aortic anastomosis of the left or right subclavian artery and the sensor location on the corresponding radial artery. Since the vasculature of the two arms is very similar, the two equalization devices 28 will generally have similar transfer functions, but they need not be identical. These transfer functions may be may be tailored to each individual patient 20 based on age, weight, and other factors. After processing by the corresponding equalization device 28, each equalized signal 28a may be output to a corresponding offset correction device 30 or may be output directly to a differential amplifier 32. Each offset correction device 30 (described in detail below) corrects for small inaccuracies in the flow signal that would be caused by any "DC offset" between the two sensor signals.
Each signal output by either the corresponding offset correction device 30 or the corresponding equalization device 28 is input to one input terminal of the differential amplifier 32. The differential amplifier 32 generates a difference signal 32a equal to the amplified difference between the two input signals. The difference signal 32a is roughly proportional to the instantaneous blood flow in the aortic arch 10.
The difference signal 32a output by the differential amplifier 32 is input to a pressure-to-flow transformation device 34. This transformation device 34 can be implemented with a microprocessor or "DSP chip" and converts the difference signal, which represents the pressure drop in the 2-cm section of the aorta 10 between the right and left subclavian arteries 11 and 12, to the flow signal, which represents the instantaneous flow rate of blood in that 2-cm section.
The transformation device 34 is well-known to those skilled in the art of flowmeters. For example, for an orifice-type flow sensor, flow is related to pressure by: ##EQU1## where q is the flow, C is a coefficient (fixed for a given fluid and flowmeter), P 2 is the pressure downstream of the flow sensor, and P 1 is the pressure upstream of the sensor. For this type of flow sensor, the pressure-to-flow transformation device 34 simply implements the equation, ##EQU2## where ΔP represents the input to the device 32a (P 1 -P 2 ).
While the behavior of the aortic arch 10 will be more complex than that of a simple, orifice-type flow sensor, the overall method and means for determining flow based on a pressure difference that is monotonically and directly related to the flow is identical. The present invention exploits this behavior to determine aortic blood flow from the easily measured pressure difference between the two subclavian arteries 11 and 12.
At low flow rates, the flow will be laminar, and the pressure drop, ΔP, is directly proportional to flow. This regime is known as Hagen-Poiseuille flow. The rate of change in pressure per unit length, dp/dx is: ##EQU3## where V is the average blood velocity, μ is the viscosity of the blood, and r o is the internal radius of the aorta 10.
This expression may be rewritten for the pressure drop, ΔP, generated by flow through a vessel of length, ΔX, as follows: ##EQU4## An expression for the blood flow rate q, integrated over cross-section of the aorta 10, is:
q=πr.sub.o.sup.2 ρV, (5)
where ρ is the blood density. Now, substituting V from Eq. (5) into Eq. (4) and rearranging gives: ##EQU5## Thus, the laminar blood flow rate q is directly proportional to the pressure drop ΔP, and the proportionality constant is composed of parameters that are essentially fixed for a given patient. In the aorta 10, Δx is the distance--about 2 cm--between the anastomoses of the two subclavian arteries 11 and 12. The laminar flow relationship given in Eq. (6) holds only for relatively-low flow velocities, up to a Reynold's number, Re, of about 1,000 to 5,000. The line 38 shown in FIG. 4 graphically represents the laminar flow region defined by Eq. (6).
At relatively high flow velocities, the flow is turbulent. In this regime, the friction factor, f, will asymptotically approach a constant value, which depends on the roughness of the aortic walls. The friction factor f ##EQU6## where ΔP is the pressure drop between the two measurement points, ρ is blood density, V is average flow velocity, L is the distance between the two measurement points, and D is the diameter of the vessel. Solving for average blood flow velocity: ##EQU7## Solving Eq. (5) for V gives: ##EQU8## Now substituting Eq. (9) into Eq. (8) and solving for q gives; ##EQU9## Then, solving for q gives: ##EQU10## Thus, the flow rate q is proportional to the square root of the pressure drop ΔP in turbulent flow. In measuring aortic blood flow, the proportionality constant is composed of parameters that are essentially fixed for a given patient. Curve 40 of FIG. 4 graphically represents the turbulent flow region defined by Eq. (11).
As shown by curve 38 of FIG. 4, for low velocity laminar flow the flow rate is proportional to ΔP, and the proportionality constant is ρπr o 4 /8μΔx. As shown by curve 40 of FIG. 4, for high velocity turbulent flows the flow rate is proportional to the square root of ΔP and the proportionality constant is π(ρr o 5 /2fΔx) 1/2 . For flow rates lying between these regimes, the behavior is intermediate between the laminar and turbulent flow regimes, as shown by curve 36. The important result is that the flow rate is related in an essentially-fixed, monotonic way to the subclavian pressure difference, ΔP.
The exact shape of the actual aortic pressure/flow curve 36 of FIG. 4 cannot be obtained mathematically with the same ease as the curves in the laminar flow and turbulent flow regions described above. However, it is straightforward to measure the q versus ΔP relationship either with live patients, with cadavers, or with physical models, fabricated by casting from cadavers. After the q versus ΔP relationship has been measured for a range of body types and sizes, this information is used in the apparatus of the present invention so that a patient's blood flow can be measured with a fair degree of accuracy. This is accomplished without need to determine the precise q versus ΔP relationship for that particular patient, simply by using the predetermined stored q versus ΔP curves. The q versus ΔP relationship for any particular patient is implemented in the transformation device. The relationship may be implemented using any known means such as by being selected from a stored table provided in a memory means.
It is also useful to note that corrections can be made for curved flow channels. The aorta 10 is certainly curved, so these corrections should ideally be considered in any attempt to derive a q versus ΔP relationship by analytical methods.
An important aspect of the flow measurement technique described here is that the measurement depends on the (relatively small) difference between two large signals, the equalized and corrected left and right blood pressure signals. A small (percentage) error in either blood pressure signal will lead to a relatively large error in the measurement of blood flow. The various sources of small errors in tonometric blood pressure measurements are well-known. If the offset correction devices 30 are not used, these small errors would be large enough to cause unacceptable errors in the aortic blood flow measurement. Thus, the offset correction devices 30 have an important influence on the accuracy of the measurement system.
Except for certain situations such as vigorous exercise, the aortic blood flow is highly pulsatile, and drops essentially to zero during the later part (i.e., just prior to left ventricle contraction) of the cardiac cycle. This behavior is used by the offset correction devices 30 to correct the sensor signals. During this zero-flow part of the cardiac cycle, the pressures in the two subclavian arteries and 12 will be essentially equal, and hence, their pressure difference should be nearly equal to zero.
As shown in FIG. 2, one of the two offset correction devices 30 is optional. In the most general case, two offset correction devices 30 are used, but one offset correction device 30 is sufficient for most situations. When only one offset correction device 30 is used, the output from one equalization device 28a is input directly to the differential amplifier 32. The operation of the embodiment shown in FIG. 2 will be described for the case of a single offset correction device 30, which is installed in the line carrying the left artery pressure signal.
The sensor control means 26 detects the diastolic and systolic points on the radial blood pressure waveforms. Algorithms to identify these points are wellknown. Based on these identified points, each sensor control means 26 outputs a timing signal 26b that indicates the occurrence of the zero-flow part of the cardiac cycle. For example, let t a be the running average of the period of the cardiac cycle. Assume the cycle starts at the systolic point of the right radial artery pressure waveform. One algorithm for finding the zero-flow part of the cycle would begin the zero-flow segment at t≃(0.8)t a and would end it at a time 4 ms prior to the diastolic point of the right radial artery pressure signal. This algorithm is offered as a good example, but other algorithms may be used without departing from the teachings of this invention.
The timing signals 26b are input to the offset correction device 30. Each offset correction device 30 preferably uses the timing signal 26b from the opposite arm. That is, the first offset device 30 preferably uses the second timing signal 26b, while the second offset correction device (if implemented) preferably uses the first timing signal 26b. Alternatively, each offset correction device 30 uses the same arm timing signal 26b, or uses both timing signals 26b. A second input to each offset correction device 30 is the amplified signal 32a output by the differential amplifier 32. The output of the differential amplifier 32 should be zero during the zero-flow part of the cardiac cycle. This zero-output condition is achieved by operation of the offset correction device 30 as described below.
The operation of the offset correction device 30 can be understood by referring to FIG. 3. FIG. 3 shows the internal components of the offset correction device 30. The amplified signal 32a output by the differential amplifier 32 is input to an integrator circuit 302. This integrator circuit 302 is controlled in the conventional manner by the timing signals 26b. Specifically, the output from integrator circuit 302 is reset to zero just prior to the beginning of the zero-flow time period. During the zero-flow part of the cardiac cycle, as indicated by the timing signals 26b, the integrator circuit 302 integrates the amplified signal 32a and outputs a signal equal to the integral. When the zero-flow time period ends, the integrator circuit 302 ceases to integrate its input, and the level of its output signal is "frozen". This sort of integrator circuit 302 is well-known in the art.
The output signal from the integrator circuit 302 is input to a three-state comparator 304. The three-state comparator 304 has three output states that correspond to the input≧d, input≦-d, and d>input>-d, respectively, where d is a threshold voltage In the preferred embodiment, d is chosen to represent a very small pressure--e.g. 0.01 mmHg.
The output signal from the three-state comparator 304 is input to the logic circuit 306 shown in FIG. 3. Second inputs to the logic circuit 306 are the timing signals 26b. The signals output by the logic circuit 306 are input to a digital-to-analog converter (DAC) 308.
Immediately after the end of the zero-flow time period, the logic circuit 306 is activated. First, the logic circuit 306 reads the output from the three-state comparator 304 to determine its state. Then, based on the state of the three-state comparator 304, the logic circuit 306 will execute one of three actions:
1) If the three-state comparator 304 indicates that the integral signal is greater than or equal to d, the output of the logic circuit 306 will be increased by one count.
2) If the three-state comparator 304 indicates that the integral signal is less than or equal to d, the output of the logic circuit 306 will be decreased by one count.
3) If the three-state comparator 304 indicates that the integral signal is between d and -d, the output of the logic circuit 306 will not be changed.
Referring to FIG. 3, the voltage level of the signal output by the DAC 308 is added to the voltage level of the equalized signal 28a, which is input to the offset correction device 30. The equalized signal 28a is the output of the left equalization device 28. The sum signal is buffered by a suitable amplifier 310, and is the output 30a of the offset correction device 30.
It may be seen by consideration of the above description, together with FIGS. 2 and 3, that the offset correction device 30 will act to adjust the DAC 308 out signal to a voltage level that will assure that the voltage 32a is essentially zero during the zero-flow part of the cardiac cycle. Usually, the corrected signal will not "converge" to this state until several seconds or minutes after the blood flow measurement apparatus is connected to the patient. However, once the corrected signal has "converged," it should be relatively stable.
The preferred embodiment of the first offset correction device 30 described above is presented as one example, but other embodiments of offset correction devices 30 may be used without departing from the teachings of this invention. The embodiment of the second offset correction device, when implemented in a two offset correction device apparatus, while not identical to the embodiment of the first offset correction device, follows directly from the embodiment of the first offset correction device.
The aortic blood flow measurement apparatus shown in FIG. 2 forms a feedback-controlled system, and this type of system has been studied extensively by practitioners of control system theory. Numerous variations on the operation and design of the aortic blood flow measurement apparatus will be apparent to those skilled in the art of control system theory. For example, the time required for the system to "converge" can be reduced greatly if the logic circuit 306 and comparator 304 are changed so that the logic circuit 306 output is adjusted by an amount proportional to the integrator 302 output voltage.
The aortic blood flow measurement shown in the apparatus of FIGS. 2 and 3 makes extensive use of analog voltages to represent the blood pressure signals 26a, equalized signals 28a, corrected signals 30a, and flow signals. All the functions and signals of the preferred embodiment shown in FIGS. 2 and 3 may be implemented by using one or more digital computers or microprocessors. Such a digital implementation would not be a departure from the teachings of this invention.
It should also be noted that for optimal operation, the "gain" of the two tonometer sensors 24, after modification, if any, by the associated sensor controller 26, must be approximately equal. Thus, it is recommended that the two sensors 24 be placed at as nearly identical locations on the two arms 22 as possible In addition, if "cuff calibration" is used, any gain adjustment should be applied equally to the two sensors 24.
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A non-invasive aortic blood flow sensor is disclosed. The sensor determines the blood flow in the aorta of a patient based on the pressure difference between the right and left subclavian arteries. The pressure of the subclavian arteries is non-invasively measured by determining the blood pressures in the arteries of the patient's right and left arms by means of tonometric blood pressure sensors. The signals from the tonometric sensors are first equalized to account for any pressure waveform distortion due to propagation of the pulse from the aorta to the sensor locations. Next, a correction is made for DC offset. The modified pressure signals are then compared, and the pressure difference determined. The blood flow is determined from the pressure difference by known pressure/flow relationships.
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TECHNICAL FIELD OF THE INVENTION
This invention relates generally to an universal tractor loader mounting bracket kit assembly or system for a tractor loader which can accommodate various other bracket components to permit different types of loaders to be mounted thereon.
BACKGROUND OF THE INVENTION
Many types of tractor loaders have been designed which utilize a "quick mount" system to rapidly and safely mount the loader on a tractor and to dismount the loader from the tractor. Conventional "quick mount" tractor loaders utilize a mounting bracket assembly which is secured to the tractor and which is adapted to removably receive the loader sub-frame to mount the loader on the tractor.
One problem associated with designing "quick mount" tractor loaders is the vast number of tractor makes and models. For example, some types of tractors are longer than others while other tractors are wider than others. The positioning of the front wheels of the tractor varies between makes and models and the use of mechanical front wheel drive on some tractors causes the front wheels thereof to project further forwardly, though the same frame is used as in the two-wheel drive model. Thus, tractor loader manufacturers must develop and manufacture a vast number of different loaders and a vast number of different mounting bracket assemblies to enable those loaders to be mounted on a particular tractor. For example, see U.S. Pat. Nos. 4,051,926; 4,266,906; and 4,621,973 which represent different approaches taken by Westendorf Manufacturing Co., the assignee of this invention, in mounting loaders on different types of tractors.
It is therefore a principle object of the invention to provide a mounting bracket kit assembly which is adapted to receive different mounting bracket components thereon to accommodate a particular type of tractor loader.
Still another object of the invention is to provide a basic mounting bracket system, and different components therefore, which enables the tractor loader manufacturer to substantially reduce its inventory.
Still another object of the invention is to provide a mounting bracket system for tractor loaders to enable the bracket system to be modified to accommodate various types of tractor loaders.
These and other objects of the present invention will be apparent to those skilled in the art.
SUMMARY OF THE INVENTION
A basic tractor loader universal mounting bracket kit assembly or system is disclosed which is adapted to receive various other types of brackets mounted thereon to permit the assembly to accommodate various types of tractor loaders, thereby eliminating the need for a tractor loader manufacturer or dealer to maintain a large inventory.
A basic set of brackets for mounting on the tractor is provided with the basic set being adapted to receive various configurations of rear mounting tubes at the rear end thereof. The forward end of the basic set is also adapted to receive at least two different types of front mounting brackets. The sides of the basic set are also adapted to receive at least two different types of side mounts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a typical tractor loader attached to a tractor by means of the mounting bracket of this invention;
FIG. 2 is a perspective view of the basic mounting bracket assembly of this invention;
FIG. 3 is a perspective view illustrating a cross member and a sub-frame mounting bracket attached to the basic bracket assembly,
FIG. 4 is a view similar to FIG. 3 but which illustrates the basic bracket system having different bracket components mounted thereon;
FIG. 5 is a perspective view similar to FIGS. 3 and 4 but which illustrates the basic bracket system having different bracket components mounted thereon;
FIG. 6 is a perspective view similar to FIGS. 3, 4 and 5 but which illustrates the basic bracket system having different bracket components mounted thereon;
FIG. 7 is a perspective view of one form of a tractor loader.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein identical or corresponding parts are identified by the same reference numeral, the numeral 10 generally designates a tractor having a forward end 12, rearward end 14, front wheels 16, rear wheels 18 and opposite sides 20 and 22 (not shown). FIG. 7 illustrates one form of a tractor loader such as illustrated in U.S. Pat. No. 4,051,962. As seen in FIG. 7, tractor loader 24 comprises a U-shaped sub-frame 25 including side frame members 26 and 28, and front frame member 30. Towers 32 and 34 are positioned at the rearward ends of the side frame members 26 and 28 and extend upwardly therefrom as seen in the drawings. Boom arm 36 and 38 are pivotally secured to the upper ends of towers 32 and 34, respectively, and are movable with respect thereto by hydraulic cylinders 40 and 42. A materials handling attachment such as a bucket 44 or the like is pivotally secured to the forward ends of the boom arms 36 and 38 and is pivoted with respect thereto by conventional hydraulic cylinders. The towers 32 and 34 are normally provided with rearwardly presented channels or pockets 46 and 48, respectively, which are adapted to receive cross-mounting tubes so as to detachably secure the rearward end of the loader to the mounting bracket assembly mounted on the tractor, as will be described in more detail hereinafter. Further, the sub-frame 25 is either secured to the front of the mounting bracket assembly or to the sides thereof as also will be described in more detail hereinafter.
FIG. 2 illustrates the basic bracket system or assembly of this invention which is mounted on the tractor and which is referred to generally by the reference numeral 50. Assembly 50 includes a pair of side frame members 52 and 54 having an optional cross or front frame member 56 secured to the forward ends thereof and extending therebetween. In some cases, front frame member 56 is not required. Side frame members 52 and 54 are provided with a plurality of openings 58 provided therein to enable the side frame members 52 and 54 to be bolted to the opposite sides of the tractor.
Hanger plate brackets 60 and 62 are secured to the rearward ends of the frame members 52 and 54, respectively, and extend downwardly therefrom as seen in FIG. 2 and have horizontally disposed plates or shoes 64 and 66 mounted at the lower ends thereof which are provided with a plurality of mounting openings 68 formed therein.
Mounting saddles 70 and 72 are provided on the side frame members 52 and 54, respectively, between the ends thereof as seen in FIG. 2. Inasmuch as each of the saddles 70 and 72 are identical, only saddle 70 will be described in detail. Saddle 70 includes a pair of vertically spaced plates 74 and 76 which extend outwardly from side frame member 52 and which have a vertically disposed plate 78 secured thereto as seen in the drawings. A pair of upstanding spaced-apart lugs 80 and 82 are secured to the exterior surface of plate 78 as seen in the drawings.
FIG. 3 illustrates the basic bracket assembly 50 having a set of intermediate brackets mounted thereon to accommodate a particular loader. As seen in FIG. 3, bracket assembly 50 has a rear mounting bracket 84 secured thereto and a front mounting bracket 86 mounted thereon. As seen in FIG. 3, rear mounting bracket 84 includes a transversely extending mounting tube 88 which is secured to and which extends beneath the plates 64 and 66. The opposite ends of the mounting tube 88 are provided with forwardly presented pockets or channels 90 and 92, respectively, which are adapted to receive the channels 46 and 48, respectively, at the lower ends of the towers 32 and 34, respectively. As seen in FIG. 3, the front mounting bracket assembly 86 is bolted to the forward ends of the side frame members 52 and 54 and is provided with an elongated, forwardly presented channel 94 which is adapted to receive the front frame member 30 of the sub-frame 25. Front mounting bracket component 86 is provided with a transversely extending pivot bar 96 which projects outwardly from the side frame members 52 and 54 to enable the side frame members 26 and 28 to pivot thereon during the mounting and dismounting operations.
FIG. 4 illustrates the basic bracket assembly 50 having a set of intermediate brackets mounted thereon to accommodate a loader of different design than that previously described. As seen in FIG. 4, the basic mounting bracket assembly 50 may also be easily adapted to detachably mount a sub-frame of a tractor loader which does not require a front mounting pocket such as illustrated in FIG. 3. As seen in FIG. 4, a pair of side pivots 98 and 100 are secured to the saddles 70 and 72, respectively, so that the side frame members of the sub-frame of the loader may be pivoted thereover. When the side pivots 98 and 100 are utilized rather than the front receiving pocket as illustrated in FIG. 3, the tractor loader sub-frame is normally either locked onto the side pivots 98 and 100 or the rear pockets to prevent longitudinal movement relative to the mounting bracket assembly.
FIG. 5 illustrates the basic bracket assembly 50 having a set of intermediate brackets mounted thereon to accommodate a loader of different design than that previously described. As seen in FIG. 5, the rear mounting tube 102 in FIG. 5 varies slightly from that illustrated in FIG. 3 and that the front mounting bracket component 104 illustrated in FIG. 5 varies somewhat from that illustrated in FIG. 3.
FIG. 6 illustrates yet another type of adaptation of the basic bracket assembly 50 in that the side pivots 106 and 108 vary in construction from that illustrated in FIG. 4.
Thus it can be seen that a basic mounting bracket assembly 50 has been provided which may accommodate various intermediate bracket assemblies so that the bracket assembly may accommodate different types of tractor loaders thereby achieving the objectives set forth hereinabove.
Thus it can be seen that the invention accomplishes at least all of its stated objectives.
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A universal tractor loader bracket kit is described which enables a basic set of brackets to accommodate various other bracket components thereon to enable the basic set of brackets to accommodate various types of tractor loaders.
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DESCRIPTION
[0001] The present invention relates to a method for producing one-component sealing- and coating compounds with a polyurethane base.
[0002] Well known and precisely examined are binding agents for sealing- and coating compounds which contain isocyanate-prepolymers which can be produced by reaction of isocyanates with molecules with active hydrogen atoms like amines and alcohols and cure under the influence of humidity. DE-A 1 520 139 for example describes a procedure to produce moisture curing mixtures of polyisocyanates and polyketimines or polyaldimines, using isocyanate-prepolymers as polyisocyanate component. DE-A 2 018 233 describes moisture-curable preparations from isocyanate groups containing binding agents and polyoxazolidines.
[0003] EP-A 0 702 039 describes a procedure to produce isocyanate-prepolymers by reaction of aromatic or cycloaliphatic diisocyanates with a polyol component providing that there is a rest-content of monomeric diisocyanates of less than 0.5 weight % contained in the isocyanateprepolymers. When cycloaliphatic diisocyanates are used, the excessive diisocyanate has to be removed after the reaction has been finished by thin-layer destillation until the desirable rest content of less than 0.5 weight % is reached. Furthermore it is known from EP-A 0 702 039 and from DE-A 1 520 139 to add filling material and H 2 O-reactive hardener to the mentioned isocyanate-prepolymer with low rest content of monomeric diisocyanates in order to produce sealing- and coating material. To guarantee constancy of quality and storage stability of sealing- and coating material on the basis of already described prepolymers only a low content of water is allowed to exist. This way for example, a reaction of moisture which is introduced by the filling material with free isocyanate groups under cleavage of CO 2 can lead to a dangerous increase of pressure within the bucket. Apart from that, we see that—in the presence of hydrolysis-sensitive, latent amine curing agents for example of the type of oxazolidines, ketimines or aldimines—the lowest degree of rest moisture by reaction with the curing agent leads to a thickening or curing of the material in the bucket. After a certain degree of viscosity of more than 8000 mPas is reached, the material is no more brushable or otherwise applicable. That is why in practise expensive drying techniques like for example dehydrating agents or a very costly physical predrying are applied.
[0004] Based on this, the invention had for its purpose to provide a manufacturing process of sealing- and coating compounds so that an improved storage stability plus a simultaneous reduction of processing costs can be attained.
[0005] The following steps show how the problem is solved according to the invention by some in-situ process:
[0006] stirring a mixture containing a polyol component and a diisocyanate component so that an isocyanate-prepolymer with a rest of monomeric diisocyanate of >2 weight % is obtained intermediary.
[0007] dispersing of pigments and anorganic filling material and adding of solvent while stirring, so that the rest of the monomer diisocyanate reacts with the moisture that is introduced by the filling material and a H 2 O-content of <0.01 weight % is obtained in the reaction mixture.
[0008] adding a H 2 O-reactive latent curing agent and at least one catalyst, if necessary, and air-proof filling of the resulting sealing- and coating compound.
[0009] Advantages of the invention can be recognized in the sub claims.
[0010] The invention will subsequently be explained in detail by one illustration and some performing examples.
[0011] [0011]FIG. 1 shows the viscosity course of an one component polyurethane coating compound according to the invention (lower curve) and of a coating compound according to the technology standard (upper curve).
[0012] In the process according to the invention in hand concerning the production of sealing- and coating compounds, isocyanate-containing prepolymers are produced as basis binding agents in a first step of process. It is important to out door floor coatings, especially of balconies that isocyanate-containing prepolymers are saponification- and light-stable at the same time. Isocyanateprepolymers on the basis of polyetherpolyoles are saponification stable but less light-stable. On the other hand isocyanateprepolymers on the basis of polyesterpolyols, polyesterpolycarbonatepolyols and polyhydroxyacrylates are light-stable but can't be brought into direct contact with concrete floor surface because of their bad saponification stability. Beyond this, these polyoles have a very high grade of viscosity which requires the use of large quantities of solvents. But the application of large amounts of solvents is to the detriment of the ecological standpoint. By mixture of polyestercarbonatediols or polyhydroxyacrylates with polyether, binding materials are obtained that show a low viscosity and the curing of these binders with cycloaliphatic diisocyanates and maybe latent amine hardeners build up blockcopolymers that show a very high saponification- and light stability. In the process according to the invention a mixture of polyalkyleneetherpolyol and polyesterpolycarbonatediol are preferably used as a polyol component. Mixtures of a polyalkyleneetherpolyol and a polyester-polyetherpolyol (Fatty acis ester) or a polyhydroxyacrylate can be used as well.
[0013] Polyalkyleneetherpolyoles of the molecular weight of approx. 1000 until approx. 6000 g/mol are used preferably. Special preference is given to a polypropyleneglycol, difunctional, of an average molecular weight of 2000 g/mol or to a polypropyleneglycol, trifunctional, with an average molecular weight of 4000 g/mol. According to the invention a polyestercarbonate of an average molecular weight of approx. 1500 g/mol to approx. 2500 g/mol, preferably of 2000 g/mol, is used as a further component of the polyol mixture in the process. The polyesterpolycarbonatediols, for example, present polycarbonates of the 6-hydroxyhexaneacid-6-hydroxyhexylester.
[0014] According to the invention the process uses preferably cycloaliphatic diisocyanates as an initial compound for the isocyanateprepolymer. Cycloaliphatic diisocyanates are called those that show at least one cycloaliphatic ring per molecule and have at least one of both isocyanategroups directly attached with a cycloaliphatic ring. Appropiate as such are for example cycloaliphatic diisocyanates like 1-isocyanato-3,3,5-trimethyl-5-isocyanato-methylcyclohexane (Isophoronediisocyanate IPDI).
[0015] The used diisocyanates show varying reactive isocyanategroups within the molecule. 1-Isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (Isophoronediisocyanate IPDI) for example has one primary and one secondary isocyanategroup that are significantly different on account of their reactivity concerning the OH/NCO reaction.
[0016] In presence of the Lewis acids, like for example dibutyltindilaurate (DBTL), the reactivity of the secondary NCO group (see reaction way a)) is about one factor 10 higher than that of the primary NCO group (see reaction way b)—(N. Marscher, H. Höcker, Makromolekulare Chemie 191, 1843-1852 (1990)).
[0017] The conversion of IPDI with diols in a molar ratio of 2:1 following the above mentioned reaction scheme results in a kinetic controlled product distribution of the reaction products 1 to 2 in a ratio of approx. 9:1. As a consequence, about 10% of the monomeric diisocyanate do not react at all with polyol and at the end of the reaction are left as residual monomers. This yields in case of a reaction of a diol with an average molecular weight of about 2000 g/mol with IPDI to a residual monomeric content of IPDI of 2.5-2.8 weight %.
[0018] The production of the prepolymer takes place by stirring the polyol components and the IPDI in a vacuum-dissolver within a temperature range of 50° C. to 100° C., preferably at 90° C., until the content of the monomeric IPDI is not decreasing anymore.
[0019] In a second process step, without isolating the yielded reaction products, the pigments and the inorganic filling material of the group of heavy spar (BaSO 4 ), calcium carbonate, talcum or quartz powder, which show a water content of 0.1 to 1 weight %, in an amount up to 60 weight %—with regard to the entire weight of the components—are added also at 90° C. by being intensively stirred. Simultaneously with the pigment powder and filling material, a solvent of the group of ethylacetate, butylacetate, methylethylketone, methoxypropylacetate, toluene, xylene, or mixtures of the same in a quantity of up to 20 weight % with regard to the total weight of all components, is added. It is to be stirred at 90° C. for another 45 minutes and the excessive monomeric diisocyanate reacts with water which has been brought in by the filling materials. After cooling and adding of a hydrolysis-sensitive, latent curing agent and of at least one catalyst, the material is filled air-proof. Sealing- and coating compounds that are produced this way excell by a special low water content and from this results a high storage stability.
[0020] The hydrolysis-sensitive, latent curing agents can be chosen out of the group of oxazolidines, bisoxazolidines, ketimines or aldimines; the at least one catalyst can be chosen out of the group of p-toluenesulfonacid, dibutyltindilaurat, zinc chloride or organic acidanhydrides. A bisoxazolidine hardener is used preferably. The hardening of this system is based on a reaction of the oxazolidinerings with humidity of air by a cleavage of the oxygen bond of the oxazolidine ring. The reaction of the so formed aminealcohol with the isocyanate prepolymer follows.
[0021] [0021]FIG. 1 shows the viscosity course of a one component polyurethane coating compound for the in-situ-process according to the standard of technology (curve above) over a period of 8 weeks and a storage temperature of 40° C. It is evident from the illustration that the viscosity flux in case of the process according to the invention that is determined due to the reaction of the excessive monomeric diisocyanate with the water introduced by the filling materials and so leads to a drying of the coating compound, is significantly more favourable than the process without desiccation according to the standard of technology.
EXAMPLES
Example 1
[0022] 1200 g polypropyleneglycol, difunctional, average molecular weight 2000 g/mol, 1200 g polyesterpolycarbonatediole, average molecular weight 2000 g/mol, (Desmophen C 200, Bayer Company) and 550 g 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), are stirred at 90° C. in a vacuumdissolver until the concentration of monomeric IPDI (approx. 2,5-2,8 weight % IPDI) does not decrease anymore (approx. 90 minutes). Subsequently 4834 g BaSO 4 , 400 g pigment powder and 1400 g xylene are added while strongly disperged at 90° C. After a stirring time of 45 minutes at 90° C. the reaction mixture is cooled down to room temperature. Then 400 g of a bisoxazolidine hardener (Härter OZ, Bayer Company), 1 g of dibutyltindilaurate and 10 g of 4-methyl-hexahydrophthalacidanhydride are added. A coating compound with the following characteristic data is obtained:
solid content: 86% viscosity at 20° C.: 2 Pas content of monomeric IPDI: 0,14% content of H 2 O: 0,005%
[0023] cured material (7 days at 23° C., 50% relative humidity):
tensile strength: 9 N/mm 2 elongation at break: 400%
[0024] Before the filling material is added the rest concentration of monomeric IPDI is 2.8% concerning the pure binding agent (30% of the total formulation) what is equivalent to a concentration of 0.0038 mol IPDI.
[0025] The water content of BaSO 4 is approx. 0.14 weight % in relation to pure BaSO 4 (48% of the total formulation) what is equivalent to a content of 0.0037 mol H 2 O.
[0026] During the stirring of 45 minutes of the reaction mixture in the presence of BaSO 4 the following desiccation reaction can be observed.
[0027] The originating amine reacts in some unspecific secondary reactions with additional NCO groups existant in the reaction mixture under formation of carbamide bindings. So approximately one can assume a stoichiometrical relation of IPDI to H 2 O of 1:1 for the desiccation reaction. This corresponds very well with the values found in practice.
[0028] Following values have been stated in the final formulation:
monomeric IPDI: 0,14 weight % => 6 × 10 −4 mol H 2 O: 0,005 weight % => 3 × 10 −4 mol
COMPARISON EXAMPLE
[0029] Into a mixture composed out of 1500 g prepolymer 1 (reaction product of a polyetherpolyol on the basis of propyleneoxide with an equivalent weight of approx. 1000 g/val with IPDI with a restmonomeric content of <0,5%, (Desmodur E 41, Bayer Company)) and 1500 g prepolymer 2 (reaction product of a polyestercarbonatediol with IPDI with a molecular weight of approx. 2000 g/mol and a restmonomeric content of 0,5% (Desmodur VPLS 2958, Bayer Company)), 4789 g BaSO 4 , 400 g pigment powder and 1400 g xylene at room temperature are added while strongly beeing disperged. 400 g of a bisoxazolidine hardener (Härter OZ, Bayer Company), 1 g dibutyltindilaurate and 10 g 4-methyl-hexahydrophthalacidanhydride are added.
[0030] A coating compound with the following characteristic data is obtained:
solid content: 86% viscosity at 20° C.: 2 Pas content of monomeric IPDI: <0,12% content of H 2 O: 0,07%
[0031] cured material (7 days at 23° C., 50% relative humidity):
tensile strength: 9 N/mm 2 elongation at break: 400%
Example 2
[0032] 1000 g polypropyleneglycol, trifunctional, average molecular weight 4000 g/mol, 1000 g of a solution of a polyhydroxyacrylate, approx. trifunctional, average molecular weight Mn=1300 g/mol, (Joncryl SCX-507, Jonson Polymer Company) in butylacetate with an OH content of 4.2% related to the solid matter and 650 g 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) are stirred at 90° C. in a vacuumdissolver until the content of monomeric IPDI (approx. 2.6 weight % IPDI) does not decrease anymore (approx. 90 minutes). Then, while being strongly disperged at 90° C., 5139 g BaSO 4 , 400 g pigment powder and 1400 g xylene are added. After a stirring time of 45 minutes at 90° C. the reaction mixture is cooled down to room temperature and 400 g of a bisoxazolidine hardener (Härter OZ, Bayer Company), 1 g of dibutyltindilaurate and 10 g of 4-methyl-hexahydrophthalacidanhydride are added.
[0033] A coating compound with the following characteristic data is obtained:
solid content: 84% viscosity at 20° C.: 3 Pas content of monomeric IPDI: 0,18% content of H 2 O: 0,005%
[0034] cured material (7 days at 23° C., 50% relative humidity):
tensile strength: 10 N/mm 2 elongation at break: 80%
Example 3
[0035] 1500 g polypropyleneglycol, trifunctional, average molecular weight 4000 g/mol, 528 g of a fatty acid ester, approx. trifunctional, average molecular weight 561 g/mol, (Sovermol 750, Henkel Company) with an OH content of 9.1 % related to the solid matter and 810 g 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) are stirred at 90° C. in a vacuumdissolver until the content of monomeric IPDI (approx. 2.8 weight % IPDI) does not decrease anymore (approx. 90 minutes). Subsequently 5039 g BaSO 4 , 400 g pigment powder and 1312 g xylene are added while being strongly disperged at 90° C. After a stirring time of 45 minutes at 90° C. the reaction mixture is cooled down to room temperature. Then 400 g of a bisoxazolidine hardener (Härter OZ, Bayer Company), 1 g of dibutyltindilaurate and 10 g of 4-methyl-hexahydrophthalacidanhydride are added.
[0036] A coating compound with the following characteristic data is obtained:
solid content: 86% viscosity at 20° C.: 2 Pas content of monomeric IPDI: 0,18% content of H 2 O: 0,005%
[0037] cured material (7 days at 23° C., 50% relative humidity):
tensile strength: 12 N/mm 2 elongation at break: 50%
[0038] The formulations of the coating compounds from the examples 1,2 and 3 contain:
[0039] 28-34 weight % prepolymer
[0040] 52-56 weight % filling material/pigments
[0041] 14-16 weight % solvents
[0042] 4 weight % latent hardener.
[0043] The sealing- and coating compounds that are produced according to the method according to the invention show a very high storage stability of at least one year.
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The invention relates to a method for producing one-component sealing and coating compounds with a polyurethane base The inventive method provides a simpler means of production as well as guaranteeing improved storage stability of the compounds produced, and comprises the following steps: agitating a mixture of polyol components and one diisocyanate component to obtain an isocyanate prepolymer with a residual content of monomeric diisocyanate of 2 wt per ct; dispersing pigments and inorganic fillers in the mixture and adding a solvent whilst agitating, the residual content of monomeric diisocyanate reacting with the moisture provided by the fillers so as to obtain an H 2 O content of <0.01 wt per ct in the reaction mixture; adding an H 2 O-reactive latent hardener and optionally, at least one catalyst, and airtight packing of the resulting sealing and coating compound.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of 35 U.S.C. 111 (b) provisional application Ser. No. 60/530,314 filed Dec. 17, 2003, and entitled Rotating Drilling Head Drive.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
FIELD OF THE INVENTION
[0003] The present invention relates generally to methods and apparatus for driving the rotating components of a rotating drilling head. More specifically the present invention relates to methods and apparatus for rotating the sealing element of a rotating drilling head in coordination with a rotating drilling string passing through the sealing element.
BACKGROUND
[0004] Rotating drilling heads employ elastomeric sealing elements to effectuate a seal between a rotating drillstring and the stationary head. The elastomeric sealing element is mounted on bearings that allow the sealing element to rotate with the drillstring. In most conventional drilling operations, the drilling head is positioned below the drill floor and above the blowout preventer. The drilling head operates to divert pressurized drilling fluids, and other materials flowing up through the wellbore, away from the drill floor.
[0005] In rotary drilling operations, the drillstring is rotated by a kelly drive or a top drive. A kelly drive engages a faceted member of the drill string, or kelly, that is connected to the drillstring. The kelly drive is often powered by a rotary table on the drill floor. Many rotating drilling heads are configured to be rotated by interfacing with the kelly either directly, or through a mechanical interface.
[0006] Top drive drilling systems rotate the drillstring using an electric or hydraulic motor mounted directly to the top of the drillstring. In top drive drilling systems no kelly is used and the rotating drilling head has to rely on the friction contact between the sealing element and the drillstring to rotate the sealing element. This friction contact is often insufficient to cause sufficient rotation of the sealing element, resulting in relative rotary motion between the drill pipe and the sealing element. A relative rotary motion between the sealing element and the drill pipe can lead to excessive wear in the sealing element, thus reducing the effective life of the seal.
[0007] Accordingly, there remains a need to develop methods and apparatus for rotating the sealing element of a rotating drilling head that overcome certain of the foregoing difficulties while providing more advantageous overall results.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0008] The embodiments of the present invention are directed to methods and apparatus for rotating a stripper assembly in use with a rotating drilling head. The preferred drive systems seek to synchronize the rotation of the rotating head sealing element with the rotation of the drillstring passing through the sealing element in order to reduce wear on the sealing element. A drive system is disposed external to the rotating drilling head and generates rotational motion to match the rotation of a drillstring running through the rotating drilling head. A connection transfers rotational motion from the drive system to the stripper assembly. In one embodiment, the drive system comprises a housing disposed about the drillstring and a one or more contact members connected to said housing and operable to contact the drillstring. One or more biasing members urge the contact members into contact with the drillstring so as to transfer rotational motion from the drillstring to the housing.
[0009] In one embodiment, a drive system comprises a housing containing roller assemblies that contact the drillstring. The housing is coupled to the sealing element of a rotating drilling head such that the sealing element rotates with the housing. The roller assemblies are urged into contact with the drillstring by a biasing member that maintains a contact force on the drillstring but allows tool joints and other increased diameter objects to pass through the roller assemblies. The contact force on the drillstring creates a friction force that causes the roller assemblies and housing to rotate with the drillstring, thus driving the sealing element of the drilling head.
[0010] In another embodiment, a drive system comprises a casing surrounding the drillstring and linking the sealing element of a rotating drilling head to the rotary table on the drill floor. The rotary table is rotated in unison with the drillstring such that the casing rotates the sealing element in unison with the drillstring. In certain embodiments, the casing has an upper and lower section that are rotationally coupled but are allowed to translate axially relative to each other, thus allowing for variation in the distance between the rotary table and the drilling head.
[0011] In another embodiment, a drive system comprises a rotating motor adapted to directly rotate the sealing element of a rotating drilling head. In one embodiment, a gear is coupled to the sealing element and engaged with a pinion powered by a hydraulic or electric motor. A control system operates the motor so as to rotate the sealing element in unison with the drillstring.
[0012] Thus, the present invention comprises a combination of features and advantages that enable it to overcome various shortcomings of prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:
[0014] FIG. 1 illustrates an exemplary drilling rig arrangement;
[0015] FIG. 2 illustrates an exemplary rotating drilling head;
[0016] FIG. 3 illustrates a partial sectional elevation view of one embodiment of a rotating drilling head drive system;
[0017] FIG. 4 illustrates a partial sectional plan view of the drive system of FIG. 3 ;
[0018] FIG. 5 illustrates a partial sectional elevation view of an alternate embodiment of a rotating drilling head drive system;
[0019] FIG. 6 illustrates a partial schematic view of an alternate embodiment of a rotating drilling head drive system;
[0020] FIG. 7 illustrates a partial sectional elevation view of one embodiment of a rotating drilling head drive system;
[0021] FIG. 8 illustrates a partial sectional plan view of the system of FIG. 7 ; and
[0022] FIG. 9 illustrates a partial sectional elevation view of the drive system of FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present invention with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results.
[0024] In particular, various embodiments described herein thus comprise a combination of features and advantages that overcome some of the deficiencies or shortcomings of prior art rotating drilling head systems. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art upon reading the following detailed description of preferred embodiments, and by referring to the accompanying drawings.
[0025] Referring now to FIG. 1 , there is shown a conventional rig 10 for rotating a drill bit 12 on the end of a drillstring 14 for drilling a well bore 16 . The drillstring 14 extends through a blowout preventer (“BOP”) stack 18 located beneath the rig floor 20 and includes a plurality of drill pipes 14 extending to the drill bit 12 . The drillstring 14 transmits rotational and axial movements to the drill bit 12 for drilling the well bore 16 . The drilling rig 10 includes a rotary table 22 connected to the floor 20 of rig 10 . Torque is transmitted to drillstring 14 by rotary table 22 or a top drive system suspended in the rig 10 .
[0026] Drilling fluids, often referred to as drilling mud, are pumped downward through drillstring 14 under high pressure, through drill bit 12 and then return upwardly via the annulus 44 formed between well bore 16 and drillstring 14 . The returning drilling fluid is diverted beneath the rig floor 20 to a mud reservoir 24 by means of a device commonly referred to in the industry as a rotating drilling head assembly 26 . Pump 28 draws drilling fluid from reservoir 24 and pumps it back into drillstring 14 .
[0027] A rotating drilling head assembly 26 is typically mounted below the floor 20 of the drilling rig 10 on the top of the BOP stack 18 to redirect the drilling fluid returning from the well bore 16 and to allow rotation and deployment of the drillstring 14 through the rotary table 22 . Rotating drilling head 26 includes a sealing element 30 that seals the annulus between drillstring 14 and the drilling head. Thus, drilling fluid is forced out through outlet 32 into reservoir 24 . During normal drilling operations, the blowout preventers are maintained in the “open” position, leaving only rotating drilling head 26 to contain any pressure within wellbore 16 and divert the returning pressurized drilling fluids away from the rig 10 .
[0028] FIG. 2 illustrates a typical prior art rotating drilling head assembly 26 having an outer stationary housing or bowl 48 and an inner drive ring 50 with a bearing assembly 52 disposed in between allowing drive ring 50 to rotate within bowl 48 . Outer bowl 48 includes a flange 54 for mounting the assembly 26 to the BOP stack and a flow diverter port or outlet 32 having a flange 58 for the attachment of a pipe extending to the mud reservoir. Assembly 26 further includes stripper assembly 60 , which is slidably received within drive ring 50 and connected to the upper end of drive ring 50 by a retaining clamp 62 allowing stripper assembly 60 to rotate with inner drive ring 50 .
[0029] Stripper assembly 60 includes sealing element, or stripper rubber, 30 bonded to inner drive bushing 34 . Inner drive bushing 34 has a faceted profile 44 that can be engaged to impart torque onto stripper assembly 60 . Non-rotary seals 70 and 72 , respectively, serve to isolate bearing assembly 52 from drilling fluids and to keep lubricating fluid from escaping the bearing assembly. Sealing engagement between sealing element 30 and drillstring 14 is effectuated by the sealing element being stretched to fit around the drillstring.
[0030] Referring now to FIGS. 3 and 4 a rotating drilling head drive system 100 is shown engaged with drillstring 14 and rotating drilling head assembly 26 . Drive system 100 comprises housing 110 and roller assemblies 120 . Housing 110 includes an upper portion 112 containing roller assemblies 120 and a lower portion 114 having a faceted outer surface adapted to engage faceted surface 44 of stripper assembly 60 . Each roller assembly 120 includes roller 122 , shaft 124 , biasing members 126 , and base 128 .
[0031] Roller 122 engages drillstring 14 and is rotatably mounted to shaft 124 . Shaft 124 is supported by biasing members 126 , which push roller 122 against drillstring 14 . Biasing members 126 are affixed to housing 110 by base 128 . Rollers 122 are preferably constructed from a material having a surface that will provide sufficient contact with drillstring 14 without damaging the drillstring. For example, roller 122 may be constructed from a steel core covered with a resilient coating.
[0032] Rollers 122 are urged against drillstring 14 by biasing members 126 . Biasing members 126 act to apply sufficient force to maintain the contact of rollers 122 on drillstring 14 but also allow increased diameter portions of the drillstring, such as tool joint 50 , to pass through the rollers. Biasing members 126 are supported by base 128 , which is attached to housing 110 . Biasing members 126 may be coil springs, leaf springs, hydraulic springs, or any other type of biasing system that support rollers 122 .
[0033] Drillstring 14 is moved axially while being rotated about its longitudinal axis. Rollers 122 allow for axial translation of drillstring 14 . Rollers 122 grip drillstring 14 so that the rotation of the drillstring imparts a torque on housing 110 that is transferred through faceted members 114 and 44 into stripper assembly 60 . Thus, stripper assembly 60 will rotate with substantially the same rate of rotation as drillstring 14 , reducing wear on the stripper assembly.
[0034] Drive system 100 is shown having three rollers 122 but any number of rollers may be used to achieve sufficient transfer of torque to the drive system from drillstring 14 . In the preferred embodiments, the surface area of the engagement between drive system 100 and drillstring 14 is maximized in order to minimize the contact stress, or pressure, on the drillstring. Non-rolling contact members could also be used as an alternative to rollers 122 , as long as wear to drillstring 14 is minimized.
[0035] Drive system 100 is shown as an additional component that interfaces with stripper assembly 26 but it could also be integrated into the stripper assembly. In certain embodiments, drive system 100 may be locked, or otherwise releasably latched, to stripper assembly 26 to maintain the position of the drive system during back-reaming or to provide positive engagement during installation and removal of the drive system. As an alternative to engaging stripper assembly 26 , drive system 100 may also be constructed to directly engage the rotating section of bearing assembly 52 .
[0036] Referring now to FIG. 5 , an alternative drive system 130 is shown connecting drilling head 26 to rotary table 22 . Drive system 130 includes an upper casing 132 and a lower casing 134 joined at connection 140 . Upper casing 132 has upper end 138 coupled to rotary table 22 so that the rotary table can be used to rotate the upper casing. Connection 140 transfers torque from upper casing 132 to lower casing 134 . Connection 140 preferably allows axial translation between casings 132 and 134 so as to allow for height variations between drill floor 20 and drilling head 26 . Lower casing 134 has a faceted lower end 136 adapted to interface with faceted profile 44 of stripper assembly 60 .
[0037] Therefore, the rotation generated by rotary table 22 is transferred through upper casing 132 and lower casing 134 into stripper assembly 60 . Because the relative rotary slippage between stripper assembly 60 and drillstring 14 is reduced, the service life of the stripper assembly is increased. In the preferred embodiments, rotary table 22 is synchronized with the rotation of drillstring 14 so as to closely match the rotation of the drillstring and stripper assembly 60 . In top drive drilling systems, this synchronization is likely carried out by a control system regulating the rotational speed of the top drive and the rotary table.
[0038] Referring now to FIG. 6 a second alternative drive system 150 is shown. Drive system 150 includes a drive pinion 152 that engages corresponding gear 63 attached to flange 62 . Flange 62 is connected to the rotating portion of head 26 such that stripper assembly 60 rotates with the flange. Drive pinion 152 is rotated by hydraulic motor 154 , which is powered by pump 156 and controlled by controller 158 . In alternate embodiments, an electric, pneumatic, or other motor may replace hydraulic motor 154 .
[0039] The speed of motor 154 is controlled so as to rotate stripper assembly 60 at the same rotational speed of a drillstring passing through the stripper assembly, which reduces wear on the stripper assembly. Thus, in the preferred embodiments controller 158 is linked to the drilling control system so as to match the rotational speed of stripper assembly 60 to the rotational speed of a top drive or kelly drive.
[0040] Referring now to FIGS. 7-9 , a rotating drilling head drive system 200 is shown engaged with drillstring 14 and rotating drilling head assembly 26 . Drive system 200 comprises housing 210 , roller assemblies 220 , and adapter plate 230 . Housing 210 comprises an upper portion 212 containing roller assemblies 220 and drive lugs 215 that connect housing 210 to adapter plate 230 . Adapter plate 230 is connected to stripper assembly 60 via bolts 232 or some other rigid connection. Roller assemblies 220 engage drillstring 14 and transfer torque from the drillstring through adapter plate 230 to stripper assembly 60 .
[0041] As can be seen in FIG. 9 , each roller assembly 220 includes roller 221 , upper link 222 , and lower link 223 . Lower links 223 are pivotally connected to housing base plate 214 by individual lower anchor blocks 224 . Upper links 222 are pivotally connected to follower plate 216 by individual upper anchor blocks 225 . Biasing member 218 is disposed between follower plate 216 and housing base plate 214 so as to urge the follower plate upward. Biasing member 218 may be one or more coil springs, a hydraulic spring system, or any other system for urging follower plate 216 upward.
[0042] The upward movement of follower plate 216 and upper anchor blocks 225 moves rollers 221 inward toward the center of housing 210 and drillstring 14 . Rollers 221 allow drillstring 14 to move axially while being rotated about its longitudinal axis. Biasing member 218 applies sufficient force to maintain the contact of rollers 221 on drillstring 14 but also allow increased diameter portions of the drillstring, such as tool joint 50 , to pass through the rollers.
[0043] Rollers 221 are preferably constructed from a material having a surface that will provide sufficient contact with drillstring 14 without damaging the drillstring. For example, rollers 221 may be constructed from steel cores having a concave outer surface covered with a resilient coating. Drive system 200 is shown having three rollers 221 but any number of rollers may be used to achieve sufficient transfer of torque to the drive system from drillstring 14 . In the preferred embodiments, the surface area of the engagement between drive system 200 and drillstring 14 is maximized in order to minimize the contact stress, or pressure, on the drillstring.
[0044] To install drive system 200 , follower plate 216 is pushed downward, compressing biasing member 218 and moving rollers 221 outward. Follower plate 216 may be maintained in the lowered position by a retainer pin (not shown) or other member that fixes the position of the follower plate relative to housing 210 . Once drillstring 14 is disposed within drive system 200 , the retainer pin is released and biasing member 218 urges follower plate 216 upward, moving rollers 221 inward until they contact the drillstring.
[0045] Drive lugs 215 are L-shaped members that engage slots 234 on adapter plate 230 . As housing 210 is rotated clockwise by the rotation of drillstring 14 , the horizontal portion of drive lugs 215 prevent vertical disengagement of the lugs and adapter plate 230 . Therefore, system 200 will rotate stripper assembly 60 whether drillstring 14 is being moved downward, such as in normal drilling, or upward, such as during backreaming. Lugs 215 can be disengaged from slots 234 by rotating drillstring 14 , and therefore housing 210 , counterclockwise and upward.
[0046] While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.
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Methods and apparatus for rotating a stripper assembly in use with a rotating drilling head. A drive system is disposed external to the rotating drilling head and generates rotational motion to match the rotation of a drillstring running through the rotating drilling head. A connection transfers rotational motion from the drive system to the stripper assembly. In one embodiment, the drive system comprises a housing disposed about the drillstring and a one or more contact members connected to said housing and operable to contact the drillstring. One or more biasing members urge the contact members into contact with the drillstring so as to transfer rotational motion from the drillstring to the housing.
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FIELD OF THE INVENTION
The present invention relates to a fluid injecting device that injects a fluid from the outside of a box into an air bag accommodated in the box to inflate the air bag so as to allow the air bag to function as a cushioning material.
BACKGROUND OF THE INVENTION
A fluid injecting device is conventionally known which injects a fluid from the outside of a box into an air bag accommodated in the box to inflate the air bag (the Unexamined Japanese Patent Application Publication (Tokkai-Hei) No. 2002-154579). As shown in FIG. 14 , the fluid injecting device has an article loading station 101 , a banding station 102 , and a fluid supply station 103 provided along a conveying line 100 . An empty box 104 is conveyed from upstream of the article loading station 101 . Then, in the article loading station 101 , an article 105 is loaded into the box 104 . Subsequently, as shown in FIG. 15 , an air bag 107 is placed on the article 105 ; a nozzle 106 has been installed in the air bag 107 . On this occasion, the air bag is installed so that the nozzle 106 projects out of the box 104 .
Then, in the banding station 102 , as shown in FIG. 16 , a cover 108 is placed on the box 104 to close it. The box 104 is then tied with a band 109 .
Then, in the fluid supply station 103 , a fluid is injected into the air bag 107 through the nozzle 106 to inflate the air bag 107 . The air bag 107 thus functions as a cushioning material in the box 104 .
After the operation of injecting air into the air bag 107 is completed, the nozzle 106 is removed.
However, the prior art fluid injecting device can be used only if the nozzle is set at the same height in the box, that is, only if the box has the same height. Accordingly, the prior art fluid injecting device has poor general purpose properties. Thus, a fluid injecting device has been desired which is applicable to the case in which the air bag is accommodated in a box of a different height.
SUMMARY OF THE INVENTION
The present invention is made to solve the above problem of the prior art. It is thus an object of the present invention to provide a general-purpose fluid injecting device that can also be used if an air bag is accommodated in a box of a different height.
An aspect of the present invention set forth in Claim 1 provides a fluid injecting device that injects a fluid into an air bag through a nozzle projecting from a box, the air bag being housed in the box, the fluid injecting device being characterized by comprising means for detecting a height position of the nozzle, and control means for varying the height position of the fluid injecting means in accordance with the detection.
An aspect of the present invention set forth in Claim 2 provides the fluid injecting device according to Claim 1 , characterized in that the nozzle height position detecting means comprises a sensor that detects a top surface of the box.
An aspect of the present invention set forth in Claim 3 provides the fluid injecting device according to Claim 2 , characterized in that the injection of the fluid is ended in accordance with the detection carried out by the sensor.
According to the aspect of the present invention set forth in Claim 1 , a fluid can be automatically injected into air bags housed in boxes of various sizes.
According to the aspect of the present invention set forth in Claim 2 , not only the effects of the aspect of the present invention set forth in Claim 1 are provided but it is also possible to easily and reliably detect the height position of the nozzle set so as to project from the top of the box.
According to the aspect of the present invention set forth in Claim 3 , not only the effects of the aspect of the present invention set forth in Claim 1 are provided but it is also possible to end the injection of the fluid by detecting that the top surface of the box has been inflated. Consequently, the amount of fluid injected can be optimized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the present invention (embodiment of the present invention).
FIG. 2 is a sectional view of a box showing its inside (embodiment of the present invention).
FIG. 3 is a diagram showing the appearance of the banded box (embodiment of the present invention).
FIG. 4 is a diagram showing nozzle height position detecting means (embodiment of the present invention).
FIG. 5 is a diagram showing the configuration of a fluid injecting device (embodiment of the present invention).
FIG. 6 is a diagram partly showing the configuration of the fluid injecting device (embodiment of the present invention).
FIG. 7 is a diagram showing the configuration of the fluid injecting device (embodiment of the present invention).
FIG. 8 is a front view of an operation of a gripping device (embodiment of the present invention).
FIG. 9 is a perspective view of a presser member and a receiving member (embodiment of the present invention).
FIG. 10 is a sectional view of FIG. 9 (embodiment of the present invention).
FIG. 11 is a diagram showing a variation of the nozzle height position detecting means (embodiment of the present invention).
FIG. 12 is a perspective view of a variation of the presser member (embodiment of the present invention).
FIG. 13 is a side view of FIG. 12 (embodiment of the present invention).
FIG. 14 is a schematic diagram of the configuration of a prior art fluid injecting device (prior art).
FIG. 15 is a sectional view of a box in which an article and an air bag are accommodated (prior art).
FIG. 16 is a perspective view of the box (prior art)
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The entire configuration of a fluid injecting system will be described with reference to FIG. 1 . In this figure, 1 is a conveying line. The conveying line 1 is composed of a belt conveyor or the like, and the conveying line 1 conveys a packing box 2 from upstream to downstream (in the drawing, from left to right).
An article loading station 3 , a banding station 4 , and a fluid injecting station 5 are arranged at intervals on the conveying line 1 from upstream to downstream.
An empty box 2 is conveyed from upstream of the article loading station 3 toward the article loading station 3 . As shown in FIG. 2 , in the article loading station 3 , an article 6 is loaded into the packing box 2 , and a deflated air bag 7 is placed on the article 6 . A nozzle 8 having a check valve is installed in the air bag 7 . The nozzle 8 is set so as to project out of the box 2 .
As shown in FIG. 3 , in the banding station 4 , a cover 9 is placed on the packing box 2 , and then, an outer periphery of the box 2 is tied with a band 10 . The banding station 4 is provided with a cover setting device (not shown in the drawings) that automatically places the cover 9 on the box 2 and a banding device (not shown in the drawings) that automatically winds the band 10 around the outer periphery of the box 2 .
In the fluid injecting station 5 , a fluid is injected into the air bag 7 in the box 2 through the nozzle 8 projects out of the box 2 to inflate the air bag 7 . This allows the air bag 7 to function as a cushioning material for the article in the box 2 .
As shown in FIG. 1 , the fluid injecting device 5 is provided with a nozzle presence detecting means 18 for detecting whether or not the nozzle 8 is attached to the box 2 . The nozzle presence detecting means 18 detects whether or not the nozzle 8 is present in the box 2 conveyed from upstream. The nozzle presence detecting means 18 can also detect whether or not the nozzle 8 remains in the box 2 instead of being removed as described below after a fluid has been completely injected into the air bag 7 . The specific configuration of the nozzle presence detecting means 18 will be described later.
Further, as shown in FIG. 1 , the fluid injecting station 5 is provided with nozzle height position detecting means 20 . The nozzle height position detecting means 20 can detect a top surface of the box 2 , that is, the height position of the top surface of the box 2 , to which the nozzle 8 is attached.
As shown in FIG. 4 , the nozzle height position detecting means 20 can be composed of a light emitting portion 21 and a light receiving portion 22 . The light emitting portion 21 and the light receiving portion 22 are provided above the center of box 2 as shown in FIG. 4 . The light emitting portion 21 emits a laser beam R to the top surface of the box 2 . The light receiving portion 22 then receives the laser beam R reflected by the box 2 . Then, by measuring the amount of time after the light emitting portion 21 outputs the laser beam R and before the light receiving portion 22 receives the laser beam R, it is possible to measure the distance from the nozzle height position detecting means 20 to the nozzle 8 .
Further, the nozzle height position detecting means 20 can detect that the air bag 7 is filled with a fluid. That is, as the fluid is filled into the air bag 7 , the top surface of the bag 2 is pushed up by the air bag 7 as shown by an alternate long and two short dashes line in FIG. 4 . This reduces the length of optical path of the laser beam R, thus making it possible to detect that the air bag 8 is being filled with the fluid. If the optical path length changes by a predetermined amount, the supply of air from the air supply portion 19 to the nozzle 8 is ended. The nozzle height position detecting means 20 preferably detects the central portion of the top surface of the box 2 . Accordingly, the position of the nozzle height position detecting means 20 may be varied depending on the amount by which biasing means (not shown in the drawings) for biasing the box 2 toward one side of the conveying line 1 . Alternatively, a diffusion type photoelectric sensor or the like may be attached to an elevating and lowering portion, and then, the height position of the nozzle 8 (top surface of the box 2 ) may be detected by elevating or lowering the diffusion type photoelectric sensor. On the other hand, the top surface of the box 2 may not be raised even after a predetermined time has passed since the start of injection of the fluid into the air bag 7 . This makes it impossible to detect that the fluid is filled into the air bag 7 . In this case, a disadvantage such as a hole accidentally formed in the air bag 7 can be detected.
As shown in FIG. 1 , drive-away means 23 is provided downstream of the fluid injecting station 5 . The drive-away means 23 is a device that drives away a box 2 corresponding to an error to a drive-away line A that is different from the regular conveying line 1 .
That is, if the detection executed by the nozzle presence detecting means 18 indicates that the nozzle 8 has not been attached to the box 2 conveyed from upstream, the drive-away means 23 determines this to be an error and pushes out and drives away the box 2 to the drive-away line A. Further, if the detection executed by the nozzle height position detecting means 20 indicates that the air bag 7 has not been filled in spite of a predetermined flow of fluid injected into the air bag 7 , the drive-away means 23 determines this to be an error and pushes out and drives away the box 2 to the drive-away line A. Moreover, if the detection executed by the nozzle presence detecting means 18 indicates that after the fluid is filled into the air bag 7 , the nozzle 8 , which would otherwise have been removed from the box 2 , remains in the box 2 , the drive-away means 23 determines this to be an error and pushes out and drives away the box 2 to the drive-away line A.
Now, with reference to FIGS. 5 to 10 , a description will be given of the configuration of a fluid injecting device 30 provided in the fluid injecting station 5 . In FIG. 5 , 31 is an elevating and lowering portion, and the elevating and lowering portion 31 can be elevated and lowered by, for example, a motor M. When the elevating and lowering portion 31 is thus elevated and lowered by the motor M, one end of a chain 32 or the like is attached to the elevating and lowering portion 31 . The other end of the chain 32 is wound around a driving sprocket S via a sprocket (not shown in the drawings) provided at the top of a fixed portion 33 . The driving sprocket S is rotatively driven by the motor M. The elevation and lowering of the elevating and lowering portion 31 is controlled by regulating power supplied to the motor M in accordance with the detected height position of the nozzle 8 on the basis of the detection executed by the nozzle height position detecting means 20 . Control means according to Claim 1 is composed of the motor M, the driving sprocket S, and the chain 32 .
A base portion 34 is provided with the elevating and lowering portion 31 . The base portion 34 is attached to a cylinder rod 35 a of a cylinder 35 fixed to the elevating and lowering portion 31 . The cylinder rod 35 a is placed so as to approach the conveying line 1 from a direction perpendicular to the conveying line 1 when expanded and to leave the conveying line 1 when contracted. The cylinder 35 is connected to an air supply/discharge switching portion (not shown in the drawings) through supply/discharge tubes 36 , 37 .
Accordingly, the base portion 34 operates to approach or leave the conveying line 1 as the cylinder 35 a is expanded or contracted.
A pivotal shaft 38 is provided upright from the base portion 34 . A movable frame 39 is rotatably attached to the pivotal shaft 38 . When the nozzle 8 is gripped, the movable frame 39 follows the nozzle 8 . A projection 40 is provided on a bottom surface of the movable frame 39 . Further, a projection 41 is provided on a top surface of the base portion 34 . The opposite ends of a spring 42 are attached to the respective projections 40 , 41 . Thus, the force of the spring 42 prevents the movable frame 34 from moving rotatively around the pivotal shaft 38 except when the nozzle 8 is gripped.
As shown in FIG. 5 , the air supply portion 19 , shown in FIG. 1 , is provided on a top surface of the movable frame 39 . A spring 44 is provided between a rear end of the air supply portion 19 and a movable plate 43 . Further, a cylinder rod 45 a of a cylinder 45 is attached to the movable plate 43 . Accordingly, when air is supplied to or discharged from the cylinder 45 to expand or contract the cylinder rod 45 a , the movable plate 43 and the air supply portion 19 slide. As the movable plate 43 slides, the air supply portion 19 approaches or leaves the nozzle 8 .
As shown in FIG. 6 , a through-hole 47 is formed in the center of the air supply portion 19 , and a hole 19 a is also formed in a side surface of the air supply portion 19 , and an air supply tube 48 is connected to the hole 19 a . The tip of the through-hole 47 constitutes an air supply port 49 , and the air supply port 49 can be connected to the nozzle 8 to supply air to the nozzle 8 . The air supply portion 19 releases air supplied through the air supply tube 48 , to the nozzle 8 . through the through-hole 47 in the air supply portion 19 . Further, a vent pipe 50 is slidably inserted into the through-hole 47 in the air supply portion 19 . A tube 51 is connected to the vent pipe 50 .
The vent pipe 50 is used to detect the air pressure at the tip of the air supply portion 19 . When the value of the air pressure at the tip of the air supply portion 19 becomes equal to or larger than a predetermined threshold, the supply of air to the air supply portion 19 is stopped. That is, when the air bag 7 is supplied with and becomes full of air or if the supply of air to the air bag 7 is inhibited, the supplied air flows backwards through the vent pipe 50 . Thus, when air flows through the vent pipe 50 and the backward flow pressure reaches the threshold, the supply of air to the air supply portion 19 is stopped. As a result, the supply of air to the nozzle 8 is stopped. In the present embodiment, in addition to the nozzle height position detecting means 20 , the vent pipe 50 is used to detect the air pressure. However, the detection can be achieved using only the nozzle height position detecting means 20 .
As shown in FIG. 5 , the movable frame 39 is provided with a gripping device 52 . FIG. 8 is a front view of the gripping device 52 . The gripping device 52 comprises gripping portions 53 , 53 and a cylinder 54 that drives the gripping portions 53 , 53 . The gripping portions 53 , 53 are devices that grip the nozzle 8 by being closed or opened when air is supplied to or discharged from the cylinder 54 . A semicircular concave portion 55 is formed on each of the opposite surfaces of the gripping portions 53 , 53 . When the gripping portions 53 , 53 grip the nozzle 8 , the nozzle 8 can be appropriately gripped so that the two concave portions 55 , 55 sandwich the nozzle 8 between them.
The gripping device 52 grips the nozzle 8 when a fluid is injected into the air bag 7 as shown in FIG. 6 . Further, once the injection of the fluid into the air bag 7 is completed, the gripping device 52 leaves the air bag 7 while keeping gripping the nozzle 8 as shown in FIG. 7 .
As shown in FIGS. 1 and 8 , the gripping device 52 is provided with the nozzle presence detecting means 18 . The nozzle presence detecting means 18 is composed of a photoelectric switch, and so on. The nozzle presence detecting means 18 can detect whether or not the gripping device 52 has gripped the nozzle 8 .
Consequently, when the nozzle presence detecting means 18 does not detect the presence of the nozzle 8 , which would otherwise be gripped by the gripping portions 53 in order to inject the fluid into the air bag 7 as shown in FIG. 6 , it is possible to detect that the nozzle 8 has not been attached to the box 2 conveyed from upstream. Further, a fluid has been completely injected into the air bag 7 , and when the nozzle presence detecting means 18 does not detect the presence of the nozzle 8 , which would otherwise be kept gripped by the gripping device 52 leaving the air bag 7 as shown in FIG. 7 , it is possible to detect that the nozzle 8 remains attached to the box 2 , that is, the nozzle 8 remains in the box 2 instead of being removed.
In FIG. 5 , 56 is horizontal positioning means. The horizontal positioning means 56 holds a projecting end side of the nozzle 8 , which projects from the box 2 , horizontally so as to sandwich the projecting end side of the nozzle 8 between its upper and lower parts to position the nozzle 8 horizontally. The horizontal positioning means 56 is composed of a cylinder 57 extending in a vertical direction, a presser member 59 attached to a cylinder rod 58 of the cylinder 57 , and a receiving member 60 provided opposite the presser member 59 as shown in FIGS. 9 and 10 . The receiving member 60 supports the nozzle 8 at one point from below. On the other hand, the presser member 59 presses the nozzle 8 at two points so as to stride the receiving member 60 . A tapered surface is formed on the presser member 59 to regulate the lateral position of the nozzle 8 . In the horizontal positioning means configured as described above, with its lateral movement regulated by tapered surfaces 61 , 61 , the nozzle 8 is sandwiched between the presser member 59 , located above, and the receiving member 60 , located below, at three points. The nozzle 8 is thus appropriately positioned. In the above description, the receiving member 60 is provided below the nozzle 8 , while the presser member 59 is provided above the nozzle 8 . However, the receiving member 60 is provided above the nozzle 8 , while the presser member 59 may be provided below the nozzle 8 .
Now, the operation of the present invention will be described. As shown in FIG. 1 , the empty packing box 2 is conveyed from upstream of the conveying line 1 . When the box 2 reaches the article loading station 3 , the desired article 6 is loaded into the box 2 . Further, the deflated air bag 7 is placed on the article 6 . Moreover, the nozzle 8 is installed on the air bag 7 .
Then, the box 2 is conveyed to the banding station 4 , located downstream. In the banding station 4 , as shown in FIG. 3 , the cover 9 is placed on the box 2 to close it. Then, the outer periphery of the box 2 is tied with the band 10 .
Then, in the fluid injecting station 5 , as shown in FIG. 5 , the nozzle height position detecting means 20 detects the top surface of the box 2 , that is, the height position of the nozzle 8 . The height position of the elevating and lowering portion 31 is adjusted on the basis of the detection executed by the height position detecting means 20 to align the height position of the air supply portion 19 with the height position of the nozzle 8 .
Subsequently, as shown in FIG. 5 , the cylinder rod 35 a of the cylinder 35 is extended to move the base portion 34 closer to the nozzle 8 . Air is supplied to or discharged from the cylinder 57 of the horizontal positioning means 56 to contract the cylinder rod 58 . The presser member 59 is thus lowered to press the nozzle 8 from above. In this case, as shown in FIGS. 9 and 10 , the nozzle 8 is pressed at three points by the presser member 59 and the receiving member 60 , and is thus positioned horizontally.
Then, as shown in FIG. 8 , the cylinder 54 is actuated to allow the gripping portions 53 , 53 to grip the nozzle 8 . Then, as shown in FIG. 6 , the cylinder rod 45 a of the cylinder 45 is contracted to connect the air supply portion 19 to the nozzle 8 .
Then, the air supply portion 19 supplies air, which then flows through the nozzle 8 to inflate the air bag 7 .
Then, when the nozzle height position detecting means 20 , shown in FIG. 1 or FIG. 4 , detects that the top surface of the box 2 has been inflated, that is, that the air bag 8 is full of the fluid, the supply of air from the air supply portion 19 to the nozzle 8 is stopped. This in turn stops the injection of the fluid into the air bag 7 .
Then, in the state shown in FIG. 6 , the cylinder rod 45 a of the cylinder 45 is extended to separate the air supply portion 19 from the nozzle 8 . Subsequently, as shown in FIG. 7 , the cylinder rod 58 of the cylinder 57 is extended upward to separate the presser member 59 of the horizontal positioning member 56 from the nozzle 8 . Then, as shown in FIG. 7 , the cylinder rod 36 of the cylinder 35 is contracted. The base portion 34 is then separated from the box 2 with the gripping device 52 keeping gripping the nozzle 8 . That is, the nozzle 8 can be removed from the air bag 7 . In this state, the gripping device 52 is opened to drop the nozzle 8 into a recovery box. Thus, the process of injecting the fluid into the air bag 7 is completed. Nozzle removing means removes the nozzle 8 from the air bag 7 after the fluid has been injected into the air bag 7 . The nozzle removing means is composed of the cylinder 35 , the base portion 34 , the movable frame 39 , and the gripping device 52 as shown in FIG. 7 .
On the other hand, if the nozzle 8 cannot be removed from the air bag 7 as shown in FIG. 7 , the nozzle presence detecting means 18 of the gripping device 52 does not detect the presence of the nozzle 8 . In this case, the nozzle 8 remains in the air bag 7 . Consequently, the drive-away means 23 , shown in FIG. 1 , drives the box 2 in which the nozzle 8 remains, away to the drive-away line A so as to push it out.
In the above description, as shown in FIG. 4 , the nozzle height position detecting means 20 is composed of the light emitting portion 21 , located above the center of the box 2 , and the light receiving portion 22 . However, as shown in FIG. 11 , plural sets of a light emitting portion 12 and a light receiving portion 13 may be arranged in a vertical direction so that the height position of the top surface of the box 2 , that is, the height position of the nozzle 8 can be detected by the light emitting portion 12 and the light receiving portion 13 corresponding to the position where the box 2 blocks the beam R.
FIGS. 12 and 13 show a variation of the presser member 59 of the horizontal positioning means 56 . A presser member 80 comprises an attachment portion 81 attached to the tip of the cylinder rod 58 as shown in FIG. 6 , a presser piece 82 folded downward from the tip of the attachment portion 81 , and an auxiliary presser piece 83 provided inside the presser piece 82 . A presser groove 84 has a pair of tapered surfaces 85 , 85 that fans out downward. Further, the auxiliary presser piece 83 has a horizontal auxiliary presser portion 86 extending straight in the horizontal direction. The auxiliary presser piece 83 is generally L-shaped.
In the presser member 59 formed as described above, as shown in FIG. 12 , the tapered surfaces 85 , 85 of the presser portion 81 guide the nozzle 8 to the bottom of the presser groove 84 . The horizontal auxiliary presser portion 86 of the auxiliary presser piece 83 positions the nozzle 8 horizontally so that the surfaces press the nozzle 8 downward.
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A general-purpose fluid injecting device is provided that can be used if an air bag is accommodated in a box of a different height. A fluid injecting device is provided that injects a fluid into an air bag through a nozzle projecting from a box the air bag being housed in the box. The device includes a detection apparatus for detecting a height position of the nozzle and a control apparatus for varying the height position of fluid injecting device in accordance with the detection.
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TECHNICAL FIELD
The present invention pertains generally to a method and apparatus providing a transmission pump seal.
BACKGROUND OF THE INVENTION
Conventional transmission pumps are driven by output from the engine in order to transfer hydraulic fluid and thereby meet cooling, lubrication, and pressure requirements of the transmission. The transmission pump includes a pump body which is stationary relative to the transmission housing, and a pump drive gear which is rotatable within the pump body to drive the pump. Rotational forces from the engine may be transferred to the pump drive gear via a torque converter hub. It is known that transmission pumps can leak, and that such leakage diminishes pump efficiency and vehicle fuel economy.
SUMMARY OF THE INVENTION
The present invention provides a seal apparatus for a transmission pump. The seal apparatus includes a ring seal configured to seal a gap defined between a transmission pump body and a hub in order to reduce hydraulic fluid leakage. An O-ring is placed around the ring seal such that the O-ring engages the transmission pump body in an axial direction. A retainer ring configured to axially retain the ring seal and the O-ring is disposed around the hub. A torque converter seal is disposed radially between the transmission pump body and the hub. The torque converter seal applies an axial force which is transferred through the retainer ring in order to compresses the O-ring against the transmission pump body to seal in parallel with the ring seal such that the rate of hydraulic fluid leaking from the transmission pump is reduced.
The seal apparatus may also include a snap ring configured to engage and thereby axially retain the torque converter seal.
The ring seal may be generally cylindrical, or alternatively may define a v-shaped cross-section.
The ring seal may be composed of polytetrafluoroethylene (PTFE), steel, cast iron or any other suitably matched material.
The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross-sectional view of a transmission assembly operatively connected to a torque converter; and
FIG. 2 is a more detailed cross-sectional view of a transmission pump.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, wherein like reference numbers refer to like components, FIG. 1 shows a partial cross-sectional view of a transmission 8 in accordance with the present invention. According to the preferred embodiment shown, the transmission 8 is operatively connected to a torque converter 10 ; however alternate embodiments may replace the torque converter 10 with a damper assembly (not shown), or other rotating cylindrical shaft member. For illustrative purposes, only the top half of the transmission 8 and the torque converter 10 are shown. It should be appreciated, however, that the transmission 8 and torque converter 10 are generally symmetrical about the center line 12 of the transmission input shaft 14 .
The torque converter 10 includes a torque converter housing 15 which is formed to define a generally cylindrical torque converter hub 16 . The torque converter hub 16 includes an end portion 18 with multiple flat sections 19 that are adapted to engage and thereby drive a pump drive gear 26 as will be described in detail hereinafter. The torque converter 10 is operatively connected to an engine (not shown) such that the torque converter hub 16 rotates about the center line 12 at engine speed.
The transmission 8 includes a transmission pump 20 configured to transfer hydraulic fluid to meet any cooling, lubrication, and pressure requirements of the transmission 8 . The transmission pump 20 includes a pump body 22 and a pump cover 24 defining a pump cavity 23 therebetween; and a pump drive gear 26 . Rotation of the pump drive gear 26 powers the pump 20 to pressurize hydraulic fluid within the pump cavity 23 . The pump drive gear 26 defines opposing side portions 28 a , 28 b , and generally flat engagement portions 32 . The engagement portions 32 of the drive gear 26 are engaged by the flat sections 19 of the torque converter hub 16 such that the rotation of the torque converter hub 16 is imparted to the drive gear 26 thereby powering the pump 20 . While the drive gear 26 is preferably mechanically coupled to the torque converter hub 16 via the geometry of the flat engagement portions 32 and the flat sections 19 , other conventional coupling geometries such as, for example, a splined interface may be envisioned.
A bushing 40 is configured to radially support the pump body 22 on the torque converter hub 16 such that the torque converter hub 16 is rotatable. The bushing 40 of the present invention is primarily configured to bear the weight of the torque converter 10 , torque converter imbalance loads, and the radial loads generated at the pump drive gear 26 , and therefore the bushing 40 differs from more conventional designs wherein similarly disposed bushings serve both load bearing and sealing functions. The bushing 40 is preferably press fit into engagement with the pump body 22 so that there is no relative rotation therebetween. The bushing 40 is generally cylindrical and defines opposing end portions 42 , 44 (shown in FIG. 2 ).
The transmission 8 includes a stator shaft 30 at least partially circumscribed by the torque converter hub 16 and which is operatively connected to both the pump cover 24 and the torque converter 10 . The stator shaft 30 is shown as being integral with the pump cover 24 , however, these components may alternatively be separate and connected together in any known manner. A chamber 34 is at least partially defined by the pump cover 24 and the stator shaft 30 . The chamber 34 fills with pressurized hydraulic fluid when the torque converter 10 is operating in a “lock-up mode”. As is known in the art, torque converter “lock-up mode” is a mode wherein the torque converter turbine 36 and the torque converter pump 38 are coupled and rotate together in order to improve efficiency.
Referring to FIG. 2 , the pump 20 is shown in more detail. Hydraulic fluid from the pump cavity 23 can leak along the opposing side portions 28 a , 28 b of the pump drive gear 26 , and between the bushing 40 and the torque converter hub 16 as shown with arrows representing leaked hydraulic fluid. Additionally, when the torque converter 10 (shown in FIG. 1 ) is in lock-up mode, pressurized hydraulic fluid in the chamber 34 can leak between the bushing 40 and the torque converter hub 16 . A torque converter seal 46 is provided to catch and thereby preserve the hydraulic fluid which leaks past the bushing 40 . The torque converter seal 46 generally includes an elastomeric seal member 48 integrally molded onto a metallic carrier 50 . A garter spring 52 applies radial pressure bringing the seal member 48 into engagement with the torque converter hub 16 to form a seal at the interface therebetween. A snap ring 54 engages the metallic carrier 50 to axially retain the torque converter seal 46 .
The pressurized hydraulic fluid which leaks past the bushing 40 and is then caught by the torque converter seal 46 accumulates in a cavity 56 . The pressurized hydraulic fluid in the cavity 56 is ultimately transferred to a low-pressure sump or reservoir (not shown). It should be appreciated that the energy expended to increase the pressure of the hydraulic fluid which leaks past the bushing 40 is wasted and that such leakage is therefore inefficient. Accordingly, the present invention incorporates a ring seal 66 , an O-ring 68 and a vented retainer ring 70 , described in detail hereinafter, in order to reduce the amount of pressurized hydraulic fluid leakage and thereby improve the efficiency of the pump 20 . It should be appreciated that the O-ring 68 may alternatively be replaced with any elastomeric member which is compressible and circumferentially disposed and may, for example, be integrally bonded onto the vented retainer ring 70 to form a single component.
The pump body 22 defines a seal recess 72 adapted to position and retain the ring seal 66 . The ring seal 66 circumscribes a portion of the torque converter hub 16 , engages the end portion 44 of the bushing 40 , and is disposed at least partially within the seal recess 72 . Radial clearance between the seal recess 72 and the ring seal 66 , and axial clearance between the end portion 44 and the ring seal 66 are required such that the ring seal 66 generally floats in both the radial and axial directions. The ring seal 66 is not radially constrained by the pump body 22 other than when the O-ring 68 is compressed in an axial direction. The composition of the ring seal 66 can be selected to produce a given leakage flow rate and may include, for example, steel, iron, or plastic. According to the preferred embodiment of the present invention, the ring seal 66 is composed of polytetrafluoroethylene (PTFE). The ring seal 66 can be configured to define the generally cylindrical shape shown in FIG. 2 , or alternatively can define a V-shaped cross-section with a metered orifice (not shown).
A portion of the pump body 22 which defines the seal recess 72 also forms a protrusion 74 extending in an axial direction toward the torque converter 10 (shown in FIG. 1 ). The ring seal 66 is radially retained between the protrusion 74 and the torque converter hub 16 . The pressurized hydraulic fluid which leaks past the bushing 40 follows either a first flow path between the protrusion 74 and the ring seal 66 , or a second flow path between the ring seal 66 and the torque converter hub 16 , as shown with arrows representing leaked hydraulic fluid. It has been observed that the implementation of the ring seal 66 reduces the amount of pressurized hydraulic fluid leakage from the pump 20 as compared to conventional designs which rely on a bushing to seal.
The rate of pressurized hydraulic fluid leakage can be further reduced with the addition of the O-ring 68 which is configured to restrict the flow path defined between the protrusion 74 and the ring seal 66 . The O-ring 68 is disposed radially around the ring seal 66 , and is axially positioned to engage the protrusion 74 . Therefore, the O-ring 68 is configured to form a first seal at the interface between the O-ring 68 and the ring seal 66 ; a second seal at the interface between the O-ring 68 and the protrusion 74 ; and a third seal at the interfaces between the O-ring 68 and the vented retainer ring 70 .
The vented retainer ring 70 is disposed radially around the torque converter hub 16 , and is configured to axially retain the ring seal 66 and the O-ring 68 . Additionally, the vented retainer ring 70 applies an axial force tending to compress the O-ring 68 against the protrusion 74 . More precisely, during installation the metallic carrier 50 of the torque converter seal 46 is forcibly pushed into engagement with the vented retainer ring 70 , and such forcible engagement is maintained with the addition of the snap ring 54 . The installation of the metallic carrier 50 in this manner applies an axial force to the vented retainer ring 70 , and the vented retainer ring 70 transfers this force to the O-ring 68 . Advantageously, the compression of the O-ring 68 against the protrusion 74 forms a tighter seal therebetween. As the O-ring 68 is compressed against the protrusion 74 , the O-ring 68 is deformed to increase the area of contact and thereby accommodate for stack variations. Additionally, hydraulic pressure between bushing end 44 and pump seal recess 72 pushes the ring seal 66 into the vented retainer ring 70 to form an axial seal, and the PTFE ring seal 66 is radially compressed to seal against the torque converter hub 16 .
While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
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The present invention provides a seal apparatus for a transmission pump. The seal apparatus includes a ring seal configured to seal a gap defined between a transmission pump body and a hub in order to reduce hydraulic fluid leakage. An O-ring is placed around the ring seal such that the O-ring engages the transmission pump body in an axial direction. A retainer ring is disposed around the hub, and a torque converter seal is disposed radially between the transmission pump body and the hub. The torque converter seal applies an axial force which is transferred through the retainer ring in order to compresses the O-ring against the transmission pump body to seal in parallel with the ring seal such that the rate of hydraulic fluid leaking from the transmission pump is reduced. A corresponding method for sealing a transmission pump is also provided.
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U.S. GOVERNMENT RIGHTS
[0001] The invention was made with U.S. Government support under contract N00019-97-C-0050 awarded by the U.S. Navy. The U.S. Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
[0002] The invention relates to the cooling of turbomachine components. More particularly, the invention relates to internal cooling of gas turbine engine blade and vane airfoils.
[0003] A well developed art exists regarding the cooling of gas turbine engine blades and vanes. During operation, especially those elements of the turbine section of the engine are subject to extreme heating. Accordingly, the airfoils of such elements typically include serpentine internal passageways. Exemplary passageways are shown in U.S. Pat. Nos. 5,511,309, 5,741,117, 5,931,638, 6,471,479, and 6,634,858 and U.S. patent application publication 2001/0018024A1.
[0004] Nevertheless, there remains room for improvement in the configuration of cooling passageways.
SUMMARY OF THE INVENTION
[0005] One aspect of the invention involves an internally-cooled turbomachine element comprising an airfoil extending between inboard and outboard ends. A cooling passageway is at least partially within the airfoil and has at least a first turn. Means in the passageway limit a turning loss of the first turn.
[0006] In various implementations, the means may comprise a wall essentially dividing the entirety of the first turn into first and second flowpath portions. A leading end of the wall may be upstream of the first turn (e.g., by at least 1.0 hydraulic diameters or, more narrowly, at least 1.5 hydraulic diameters, with an exemplary 1.5-2.5 or 1.5-2.0). The turn may be in excess of 90° or 120° and may be essentially 180°. The turn may be around an end of a wall. The element may have at least a first airfoil end feature selected from the group consisting of an inboard platform and an outboard shroud. The first turn may be at least partially within the first airfoil end feature.
[0007] Another aspect of the invention involves an internally-cooled turbomachine element having an airfoil extending between inboard and outboard ends. Internal surface portions define a cooling passageway at least partially within the airfoil. The cooling passageway has a first turn from a first leg to a second leg. A dividing wall bifurcates the cooling passageway into first and second portions and extends within the cooling passageway along a length from a wall first end to a wall second end. The first and second portions may each provide 25-75% of a cross-sectional area of the cooling passageway along said length of said wall, more narrowly, 35-65%.
[0008] The passageway may have a second turn from the second leg to a third leg. The wall first end may be proximate an end of the first leg at the first turn. The wall second end may be proximate an end of the third leg at the second turn. The wall first end may be 1.0-3.0 hydraulic diameters from the end of the first leg at the first turn. The wall second end may be 1.0-3.0 hydraulic diameters from the end of the third leg at the second turn. At the first turn, the passageway first portion may be within the second portion. At the second turn, the passageway second portion may be within the first portion. At the first turn, the passageway first portion may have a smaller cross-sectional area than the second portion. At the second turn, the passageway second portion may have a smaller cross-sectional area than the first portion. At the first turn, the passageway first portion may have a cross-section that is less wide than a cross-section of the second portion. At the second turn, the passageway second portion may have a cross-section that is less wide than a cross-section of the first portion. At the first turn, the passageway first portion may have a cross-section that is less elongate than a cross-section of the second portion. At the second turn, the passageway second portion may have a cross-section that is less elongate than a cross-section of the first portion. The element may be a vane having an inboard platform and an outboard shroud. The wall may have a number of apertures therein. The apertures may be no closer than an exemplary two hydraulic diameters from the first turn.
[0009] Another aspect of the invention involves a method for reengineering a configuration for an internally-cooled turbomachine element from a baseline configuration to a reengineered configuration. The baseline configuration has an internal passageway having first and second legs and a first turn therebetween. The method includes adding a wall to bifurcate the passageway into first and second portions. The wall extends within the passageway along a length from a wall first end to a wall second end. Otherwise, a basic shape of the first cooling passageway is essentially maintained.
[0010] In various implementations, the first cooling passageway may be slightly enlarged to at least partially compensate for a loss of cross-sectional area resulting from the addition of the wall.
[0011] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a partial, cut-away, partially-schematic, medial sectional view of a prior art airfoil.
[0013] FIG. 2 is a partial, cut-away, partially-schematic, medial sectional view of an inboard portion of an airfoil according to principles of the invention.
[0014] FIG. 3 is a partial, cutaway, partially schematic, medial sectional view of an outboard portion of an airfoil according to principles of the invention.
[0015] FIG. 4 is a partial sectional view of the airfoil of FIG. 2 , taken along line 4 - 4 .
[0016] FIG. 5 is a partial sectional view of the airfoil of FIG. 2 , taken along line 5 - 5 .
[0017] FIG. 6 is a sectional view of the airfoil of FIGS. 2 and 3 at an intermediate location.
[0018] FIG. 7 is a sectional view of the airfoil of FIG. 3 , taken along line 7 - 7 .
[0019] FIG. 8 is a partial sectional view of the airfoil of FIG. 3 , taken along line 8 - 8 .
[0020] Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0021] FIG. 1 shows a turbine element 40 shown as an exemplary vane having an inboard platform 42 and an outboard shroud 44 . An airfoil 46 extends from an inboard end at the platform to an outboard end at the shroud and has a leading edge (not shown) and a trailing edge 48 separating pressure and suction side surfaces. In the exemplary airfoil, one or more passageways of a cooling passageway network extend at least partially through the airfoil. In the exemplary airfoil, one passageway 50 extends in a downstream direction 500 along a cooling flowpath from an inlet 52 in the shroud to an exemplary closed downstream passageway end 54 which may be closed or may communicate with a port in the platform.
[0022] An upstream first leg 60 of the passageway 50 extends from an upstream end at the inlet 52 to a downstream end at a first turn 62 of essentially 180°. The first leg 60 is bounded by: an adjacent surface of a first portion 63 of a first wall 64 ; a first portion 65 of a second wall 66 ; and adjacent portions of passageway pressure and suction side surfaces (not discussed further regarding other portions of the passageway). The exemplary second wall 66 extends downstream to an end 67 at the first turn 62 . A second portion 68 of the first wall 64 extends along the periphery of the first turn 62 . A second passageway leg 70 extends downstream from a first end at the center of the first turn 62 to a second end at a second turn 72 . The second leg 70 is bounded by a continuation of the first surface of the wall 64 along a third portion 69 thereof and by an opposite second surface of the second wall 66 . The first wall 64 and its third portion 69 extend to an end 74 at the center of the second turn 72 . A second portion 75 of the second wall 66 extends along the periphery of the second turn 72 .
[0023] A third passageway leg 76 extends from a first end at the second turn 72 to a second end defined by the passageway end 54 . The third leg 76 is bounded by: a second surface of the first wall third portion 69 opposite the first surface thereof and extending downstream along the path 500 from the wall end 74 ; and a continuation of the second surface of the second wall 66 along a third portion 77 thereof. Along a portion of the third leg 76 , the exemplary second wall third portion 77 includes an array of impingement holes 80 extending into one or more impingement cavities or chambers 82 . An impingement cavity downstream wall 84 having apertures 85 separates the impingement cavities 82 from an outlet cavity 86 . An array of trailing edge cooling holes or slots 87 extend from the cavity 86 to the trailing edge.
[0024] In operation, a cooling airflow passes downstream along the flowpath 500 from the inlet 52 through the first leg 60 in a generally radially inboard direction relative to the engine centerline (not shown). The flow is turned outboard at the first turn 62 and proceeds outboard through the second leg 70 to the second turn 72 where it is turned inboard to pass through the third leg 76 . While passing through the third leg 76 , progressive amounts of the airflow are bled through the holes 80 into the impingement cavities 82 . From the impingement cavities 82 , the airflow passes out through the holes 85 into the outlet cavity 86 . From the outlet cavity 86 , the flow passes through holes/slots 87 to cool a trailing edge portion of the airfoil.
[0025] Viewed in cross-section transverse to the downstream direction, the exemplary passageway 50 is roughly transversely elongate rectangular (i.e., a radial span is substantially less than a height). In general, turning losses tend to increase with elongate passageway cross-sections (e.g., height much greater or less than radial span) and with sharper turns. Partially splitting the passageway into portions whose cross-sections (at least for one of the portions) are closer to square may reduce aerodynamic turning losses. In particular, an inboard portion may be made relatively less elongate than an outboard portion. The outboard portion may rely on a greater characteristic turn radius of curvature (e.g., mean or median) to maintain an advantageously low level of turning losses.
[0026] FIGS. 2 and 3 show a vane 140 which may be formed as a reengineered version of the vane 40 of FIG. 1 . The exemplary reengineering preserves the general cooling passageway configuration (e.g., the shape and approximate positioning and dimensioning of the walls and other structural elements) but adds an exemplary single dividing wall 240 within the first passageway 150 . For ease of reference, elements analogous to those of the vane 40 are referenced with like reference numerals incremented by one hundred. The exemplary dividing wall 240 extends from a first end 242 ( FIG. 2 ) to a second end 244 ( FIG. 3 ) and has generally first and second surfaces 246 and 248 . The dividing wall 240 locally splits or bifurcates the passageway 150 into portions 150 A and 150 B and the flowpath 600 into first and second flow portions 600 A and 600 B. In the exemplary airfoil, this bifurcation starts near the downstream end of the first leg 160 and extends through the first turn 162 , second leg 170 , second turn 172 , to near the first (upstream) end of the third leg 176 where the flow portions fully rejoin. In the exemplary embodiment, the bifurcation and rejoinder advantageously occur within the respective first and third legs (as further discussed below), although they may alternatively occur within the first and second turns.
[0027] To preserve total cross-sectional area along the bifurcated flowpath, the walls defining the flowpath may be shifted slightly relative to the baseline airfoil of FIG. 1 . For example, with a first portion 163 ( FIG. 2 ) of the first wall 164 fixed relative to its FIG. 1 counterpart, the third portion 169 may be shifted somewhat toward the airfoil trailing edge. The third portion 177 of the second wall 166 may be similarly shifted relative to its counterpart (potentially shrinking the size of any impingement or outlet cavity or being associated with a switch from double impingement to single impingement if exterior airfoil shape and dimensions are essentially maintained).
[0028] The exemplary wall 240 has an approximately S-shaped planform with arcuate first and second turn portions 250 and 252 and a relatively straight leg 254 therebetween. Portions 250 and 252 are shown having diameters D 1 and D 2 , although they may be other than semicircular. Near the ends 242 and 244 , associated end portions 255 and 256 may be relatively straight and taper to provide smooth flow split and rejoinder and may extend by lengths L 1 and L 2 beyond the turns.
[0029] FIG. 6 shows the sections of the passageway portions 150 A and 150 B having characteristic heights H 1 and H 2 between interior pressure and suction side surfaces and characteristic widths W 1 and W 2 between adjacent walls. H 1 and H 2 and W 1 and W 2 may vary slightly around each turn. At the second turn, however, the relative transverse elongatedness of the two passageway portions is reversed. This permits whichever of the two portions is inboard at each of the turns to have a less elongate cross-section.
[0030] To achieve the switch between the first and second turns, the dividing wall 240 extends generally diagonally across the passageway second leg 170 . To equalize pressure across the wall 240 during this transition, the leg 254 has a row of apertures 260 along a central portion thereof. Advantageously, the upstream and downstream ends of the row are recessed from the upstream and downstream ends of the leg 170 . FIGS. 2 and 3 show such recessing by lengths L 3 and L 4 . To minimize losses, advantageously, entering each turn, the dividing wall is continuous from upstream of such turn by a sufficient distance to provide desired flow through the turn, but not so far as to add unnecessary drag in the straight portion of the passageway leg thereahead. Advantageously, it may be continuous by at least one hydraulic diameter (of the inboard passageway portion at the adjacent end of the associated turn), more particularly, between about 1.5 and 2.0 hydraulic diameters. Accordingly, L 1 and L 4 may advantageously be of such dimension. Similarly, the wall may continuously extend downstream of the turn by a similar figure. Thus, L 2 and L 3 may be similar. Hydraulic diameter is defined as D H =4A/P, where A is the cross-sectional area and P is the wetted perimeter of the cross-section.
[0031] In the exemplary reengineering, the first turn 62 may have a turn loss parameter K T . The loss parameters for the outer and inner portions of the turn 162 (i.e., along first and second passageway portions 150 A and 150 B) may be substantially reduced, the loss along the outer portion being reduced by a greater factor due to the greater characteristic radius of curvature. For example, with an existing turn of loss parameter in the vicinity of 3.5-4, the reengineered turn may have an inboard portion of loss parameter in the vicinity of 2.0-2.5 and an outboard portion with loss parameter below 1.5, if not below 1.0. The second turn may see similar changes.
[0032] In other embodiments, the wall may be continuous between the two turns. In yet other embodiments, a wall may only extend through a single turn, although there may be individual walls for each of several turns. Depending on part geometry, the possibility exists of adding multiple walls for a given turn or turns.
[0033] One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the principles may be applied to the reengineering of a variety of existing passageway configurations. Any such reengineering may be influenced by the existing configuration. Additionally, the principles may be applied to newly-engineered configurations. Accordingly, other embodiments are within the scope of the following claims.
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An internally-cooled turbomachine element has an airfoil extending between inboard and outboard ends. A cooling passageway is at least partially within the airfoil and has at least a first turn. Means are in the passageway for limiting a turning a loss of the first turn. The turbomachine element may result from a reengineering of an existing element configuration lacking such means.
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This application is a continuation of application Ser. No. 08/525,404, filed on Sep. 8, 1995, now U.S. Pat. No. 5,647,357 the contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates in general to respiratory masks and, more particularly, to respiratory masks having flexible seals adapted to receive portions of a user's face for preventing leakage of gas being supplied to the user.
BACKGROUND OF THE INVENTION
A variety of respiratory masks are known which have flexible seals that cover the nose and/or mouth of a human user and are designed to create a continuous seal against the user's face. Because of the sealing effect that is created, gases may be provided at positive pressure within the mask for consumption by the user. The uses for such masks range from high altitude breathing (i.e., aviation applications) to mining and fire fighting applications, to various medical diagnostic and therapeutic applications.
One requisite of such respiratory masks has been that they provide an effective seal against the user's face to prevent leakage of the gas being supplied. Commonly, in prior mask configurations, a good mask-to-face seal has been attained in many instances only with considerable discomfort for the user. This problem is most crucial in those applications, especially medical applications, which require the user to wear such a mask continuously for hours or perhaps even days. In such situations, the user will not tolerate the mask for long durations and optimum therapeutic or diagnostic objectives thus will not be achieved, or will be achieved with great difficulty and considerable user discomfort.
The prior art includes several types of respiratory face masks for the types of applications mentioned above. Perhaps the most common type of mask incorporates a smooth sealing surface extending around the periphery of the mask and exhibiting a generally uniform (i.e., predetermined or fixed) seal surface contour which is intended to be effective to seal against the user's face when force is applied to the mask with the smooth sealing surface in confronting engagement with the user's face. The sealing surface typically consists of an air or fluid filled cushion, or it may simply be a molded or formed surface of a resilient seal element made of an elastomer such as plastic, rubber, silicone, vinyl or foam. Such masks have performed well when the fit is good between the contours of the seal surface and the corresponding contours of the user's face. However, if the seal fit is not good, there will be gaps in the seal-to-face interface and excessive force will be required to compress the seal member and thereby attain a satisfactory seal in those areas where the gaps occur. Such excessive force is unacceptable as it produces high pressure points elsewhere on the face of the user where the mask seal contour is forcibly deformed against the face to conform to the user's facial contours. This will produce considerable user discomfort and possible skin irritation and breakdown anywhere the applied force exceeds the local perfusion pressure, which is the pressure that is sufficient to cut off surface blood flow. Ideally, contact forces should be limited between the mask and the user's face to avoid exceeding the local perfusion pressure even at points where the mask seal must deform considerably.
The problem of seal contact force exceeding desirable limits is even more pronounced when the positive pressure of the gas being supplied is relatively high or is cyclical to high levels. Since the mask seals by virtue of confronting contact between the mask seal and the user's face, the mask must be held against the face with a force sufficient to seal against leakage of the peak pressure of the supplied gas. Thus, for conventional masks, when the supply pressure is high, headstraps or other mask restraints must be tightly fastened. This produces high localized pressure on the face, not only in the zone of the mask seal but at various locations along the extent of the retention straps as well. This too will result in severe discomfort for the user after only a brief time. Even in the absence of excessive localized pressure points, the tight mask and headstraps often may become extremely uncomfortable and user discomfort may well cause discontinued cooperation with the regimen.
Examples of respiratory masks possessing continuous cushion sealing characteristics of the type just described are provided in U.S. Pat. Nos. 2,254,854 and 2,931,356.
U.S. Pat. No. 5,181,506 describes a protective gas mask for military applications. The mask includes a three-layer face piece, the central layer of which is a thick layer of relatively stiff material having preformed V-shaped channels. The channels are "overfilled" with a gel or both gel and compressed air so as to create bulges in an inner face-contacting layer which are adapted to seal against the contours of a user's face. The inherent stiffness of the central layer in combination with the structural rigidity provided by the V-shaped channels, especially when overfilled with gel/air, results in a comparatively unyielding facial seal. Indeed, the mask is deployed in combination with a tightly fitting hood in order to draw the face piece firmly against the user's head to thereby generate the desired facial seal. As will be appreciated, the comfort afforded such a construction is quite limited and certainly not appropriate for those applications, such as respiratory therapy situations, where a user must occasionally wear a mask for prolonged periods of time.
Several classes of cushion materials, including gels and foams, were analyzed in a study by S. F. C. Stewart, V. Palmieri and G. V. B. Cochran, Arch. Phys. Med. Rehabil., Vol. 61, (May 1980). That study compared the relative advantages and disadvantages of such cushion materials when used as wheelchair cushions, specifically the effects of such materials on skin temperature, heat flux and relative humidity at the skin-cushion interface. Each of these factors, along with applied pressure in excess of local perfusion pressure, has been identified as a contributor to breakdown of skin tissue at the skin-cushion interface.
In that study, foam cushions were reported to increase skin temperatures by several degrees after a few hours of use. This was suggested to be a result of the comparatively low heat flux characteristics of foam materials. That is, the foam materials and the air entrapped within them tend to be poor absorbers and conductors of heat. Conversely, gel pads, as a group, showed a considerably higher heat flux than foam, sufficient in fact to maintain skin temperatures relatively constant after several hours of use. The sole benefit of foam versus gel reported in the study was that foams produced lesser relative humidity than gels at the skin-cushion interface. This was attributed to the open cell structure of the foams which provide a pathway through which moisture can diffuse. This seeming advantage is somewhat problematic, however, in that open cell foam tends to promote bacteria growth when exposed to perspiration. Bacteria, in turn, contaminates the foam thereby considerably hindering its useful service life.
These and other detrimental characteristics have been observed as well in the foam-type respiratory mask seals discussed above. Hence, apart from generally failing to provide optimum sealing with respect to a user's face, the inherent qualities of foam mask seals have been linked to skin irritation and breakdown, particularly at some of the more prominent facial contours such as the cheek bones and bridge of the nose.
Moreover, whether air, fluid or, in the case of U.S. Pat. No. 5,181,506, gel filled, or whether formed as an elastomer such as foam, plastic, rubber, silicone and the like, the resiliency or recoil characteristics of presently available cushion type respiratory mask seals have not been well suited to form an effective seal with the topography of the user's face in the absence of considerable headstrap tensile forces. The present inventors have discovered that headstrap tensile forces and, therefore, the compressive forces exerted by the mask against a user's face, can be reduced substantially with respect to existing cushion-type respiratory masks when the mask cushion is fabricated from materials having recoil characteristics analogous to that of human fat. Such a cushion has been found to behave much like natural biological tissue and tends to conform naturally to a user's face under the influence of very low headstrap forces. The present inventors have also discovered that, in addition to their other aforementioned advantages, gel materials can be produced that simulate the recoil properties of human fat tissue.
An advantage exists, therefore, for a respiratory mask facial seal comprising a seal cushion formed of a gel that affords an effective yet comfortable and non-damaging seal with a user's facial contours.
SUMMARY OF THE INVENTION
The present invention provides an improved flexible respiratory mask facial seal, as well a respiratory mask incorporating such seal, which reliably and comfortably seals the facial contours of a user.
The facial seal comprises an annular member including a peripheral sidewall bounded by an inner end and an outer end generally opposite the inner end. The inner end is adapted for attachment to the shell or body portion of a respiratory mask and the outer end defines a contoured sealing surface adapted for confronting sealing engagement with a user's face.
The annular member is formed of a gel substance such as a viscoelastic polyurethane polymer possessing resilience or recoil characteristics corresponding to those of human fat tissue. The annular member may be deployed with or without a protective covering. In the absence of such a covering, the inherent tacky quality of the gel substance serves to enhance adhesion of the facial seal to the user's face. Alternatively, if tackiness is not desired, the surface of the annular member may be covered with a coating of powdered talc, silicone or similar biocompatible material. Most preferably, however, the annular member is encapsulated in a thin, pliable, membranous covering to enhance the durability and washability of the facial seal.
Because the facial seal simulates the recoil characteristics of human fat tissue, the user experiences the sensation of a natural substance against his skin when the mask is donned. Consequently, a mask provided with such a cushion can be comfortably urged into continuous sealing engagement with a user's face with less headstrap tension than other masks heretofore known in the art. Furthermore, the fat-like qualities of the gel cause the gel to effectively fill gaps and mold to other facial contours thereby minimizing leakage of pressurized gas supplied to the mask. The gel material also serves to efficiently dissipate heat while resisting the bacteria growth associated with foam type mask seals.
Other details, objects and advantages of the present invention will become apparent as the following description of the presently preferred embodiments and presently preferred methods of practicing the invention proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more readily apparent from the following description of preferred embodiments thereof shown, by way of example only, in the accompanying drawings, wherein:
FIG. 1 is a front elevation view of a respiratory mask including a first preferred embodiment of a facial seal constructed according to the present invention;
FIG. 2 is a side elevation view of the respiratory mask of FIG. 1 when in confronting, sealing engagement with a user's face, the respiratory mask being schematically depicted in communication with a source of respiratory gas;
FIG. 3 is a cross-section taken along line III--III of FIG. 1;
FIG. 4 is a cross-section taken along line IV--IV of FIG. 2; and
FIG. 5 is an elevational cross-section view similar to FIG. 3 of a respiratory mask including a further preferred embodiment of a facial seal constructed according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIGS. 1 and 2, there is generally indicated at 10 a respiratory mask including a shell or body portion 12 having an open side 14 that defines an annular surface 16 (perhaps most clearly illustrated in FIG. 3) to which is sealingly affixed a facial seal 18 constructed according to a first presently preferred embodiment of the instant invention. The mask body portion 12 is preferably, although not necessarily, a generally rigid formed structural shell, whereas facial seal 18 is a flexible, resilient unitary member which will be described in greater detail hereinafter.
Body portion 12 also defines an opening 20 to which there may be attached a fluid coupling means such as a swivel coupling 21 or other suitable means. The opening 20 and any intervening coupling means 21 connect mask 10 via conduit means (represented by dashed line 22) to a source of gas 24, e.g., a blower of other suitable means for providing a flow of pressurized breathing gas, for administration of the gas to a user 26. The mask shown is a nasal mask which accommodates the nasal regions of the user's face. It is to be understood, however, that the invention also contemplates a full face or oral/nasal mask that accommodates both the mouth and nose of a user. As is conventional, mask shell 12 also preferably includes fastening means such as tabs 25 or the like to which may be connected suitable adjustable retention straps (not illustrated) for retaining the mask with respect to the user's face.
Seal 18 includes a solid yet highly resilient and self-sustaining compressible annular member 27 comprising a peripheral wall portion 28 having an annular base or inner end 30 (FIG. 3) configured substantially similar to the annular surface 16 of shell 12 to which it may be fixedly attached. Peripheral wall portion 28 further establishes an outer end 32 generally opposite inner end 30. The outer end 32 defines a generally annular contoured sealing surface 34 adapted for confronting, sealing engagement with a user's face. As will be more fully developed later herein, the contour of sealing surface 34 closely approximates the surface contour of a user's facial structure in the areas of the bridge of the nose, the cheeks adjacent the nose, the space intermediate the nose and upper lip, and the intervening areas contiguous to these. For a full face mask (not illustrated) the sealing surface 34 would be contoured to accommodate the user's chin in lieu of the area intermediate the nose and upper lip. In either case, variation in user facial structure, especially in the area of the bridge of the nose, for example, makes considerable seal flexibility necessary to accommodate the many different facial contours likely to be encountered.
FIGS. 3 and 4 reveal in more detail the respiratory mask seal 18. In accordance with the present invention, at least the seal or face-contacting portion or, more preferably (as illustrated), substantially the entirety of the annular member 27 is formed from a gel substance such as a viscoelastic polyurethane polymer possessing resilience or recoil characteristics corresponding substantially to those of human fat tissue. More specifically, the facial seal 18 including the annular member 27 preferably has a resiliency, as defined by durometer measured on the Shore 00 scale which is used to gauge the resiliency of very soft resilient materials, of about 10 or softer and, most preferably, about 0. Such resiliency, corresponds substantially to that of human fat tissue which also exhibits a durometer reading of 0 on a Shore 00 scale. In respect to the facial seal embodiment shown in FIGS. 1 through 4, the durometer of facial seal 18. corresponds to the resultant durometers of the annular member 27 and its later described protective covering (whose durometer is essentially negligible because of the thinness and pliability of the covering). As for the facial seal illustrated in FIG. 5 wherein the annular member 27 has no protective covering, the durometer of the facial seal is that of the annular member.
Although inherently capable of filling spatial voids, human fat tissue has negligible structural integrity and may not be self-sustaining. Consequently, any respiratory mask facial seal possessing structural characteristics essentially identical to fat would be impractical from a usage standpoint. That is, if a facial seal were fabricated from a material structurally indistinguishable from human fat tissue in terms of resiliency, it may tend to sag into an amorphous shape under the influence of gravity and thus would not effectively conform to the contours of a user's face even if headstrap tension was quite high. It will be appreciated, therefore, that a properly designed facial seal must substantially but not identically mimic human fat tissue from a structural, particularly resiliency, perspective. Stated differently, the facial seal must exhibit some measurable recoil "memory" whereby it is structurally self-sustaining, capable of gently conforming to the topography of a user's face under the influence of low headstrap tensile forces, resistant to distorting gravitational effects and self-restorable to its original configuration when removed from contact with the user's face. It must also be resistant to distortion due to positive gas pressure supplied to the mask. To simultaneously achieve these and other beneficial properties, the annular member 27 according to the present invention is preferably formed from a gel substance that, while virtually indistinguishable from human fat tissue when measured on the Shore 00 scale, exhibits a resilency or durometer on the Shore 000 scale (which scale is used to measure the resiliency of extremely soft resilient materials) of from about 20 to about 45. By comparison, human fat tissue registers a durometer of about 10 on the Shore 000 scale.
The annular member 27 may be fabricated by conventional molding techniques. For example, liquid polyurethane polymer including any plasticizers and other modifiers necessary to achieve desired finished product properties is poured or injected into an appropriately configured mold. The polymer is then permitted to cure, either with or without the application of heat depending upon the specific composition and setting characteristics of the polymer, until the product achieves its desired solid gel form. Because the polymer of the annular member does not have sufficient structural integrity to reliably adhere directly to the body portion 12 of the mask, the facial seal 18 also preferably comprises attachment means 36 which may be integrally molded into the inner end 30 of the annular member during its formation. Attachment means 36 is desirably constructed as a substantially rigid annular ring having shape corresponding to that of the inner end 30 and a wall thickness less than or equal to that of the wall thickness of the peripheral wall portion 28. At minimum, however, attachment means 36 should comprise a member less resilient than the gel substance of the annular member. To enhance bonding of the attachment means 36 to the annular member 27, the attachment means desirably includes anchorage means 38. The anchorage means may comprise spaced apart formations of the attachment means defining openings or similar structures into or around which the fluid polymer may flow and ultimately cure during formation of the annular member.
Annular member 27 also preferably comprises a plurality of integral bosses 42 molded into the peripheral wall portion 28 during formation of the annular member which extend from the inner end 30 toward the outer end 32. Bosses 42 provide gentle structural support to the annular member and promote uniform compression of the annular member when such member is in contact with a user's face. The bosses should be symmetrically disposed about the peripheral wall portion and preferably correspond in number and location to the anchorage means 38. As shown in FIG. 3, a presently preferred construction envisions five such bosses 42 corresponding to five anchorage means 38.
As previously mentioned, the presently preferred embodiment of facial seal 18 contemplates that the annular member 27 be covered by a protective covering. Such covering means is identified by reference numeral 40 in the drawing figures. The covering means functions to increase the durability of the annular member while also permitting easy cleaning of the facial seal. Covering means 40 must satisfy several physical criteria. It must, inter alia: (1) resist tearing and puncturing, (2) tightly conform to the annular member 27 without changing or deforming the contours thereof, (3) be chemically compatible with the annual member, (4) be biocompatible and non-irritating to a user's skin, and (5) be sufficiently thin and supple such that its presence has a negligible impact on the resultant durometer of the facial seal 18. In this regard, covering means 40 preferably comprises a thin (approximately 2 to 10 mils thick) flexible plastic film. Urethane has been found to be preferable for this particular purpose as such material meets not only the objectives of the present invention but is also comparatively inexpensive and easy to apply to the surface of the annular member 27. The covering means 40 may be applied to the annular member by any suitable process. For instance, liquid urethane may be applied by spraying or dipping and then permitted to cure. Preferably, however, the urethane is prefabricated by vacuum forming so as to produce a skin of controllable and uniform thickness which is subsequently vacuum formed to the annular member using contentional techniques.
Once the facial seal 18 is fully assembled, it may be attached to the body portion 12 of a respiratory mask by coating the inner end 30 of the facial seal and/or the annular seating surface 16 of the mask body portion 12 with a suitable adhesive and then pressing the inner end 30 into abutment with the seating surface 16 whereupon the adhesive is allowed to cure.
In FIG. 5, wherein like references designate like or corresponding parts to those previously discussed, there is illustrated a further preferred embodiment of the facial seal of the present invention which is identified herein by reference numeral 118. Facial seal 118 differs from facial seal 18 essentially in that the annular member 27 thereof has no protective covering means on its outer surface. In all other material respects, facial seal 118 is constructed and functions substantially identically to facial seal 18.
The exposed surface of the annular member 27 of is tacky. As such, the inherent tackiness of the contoured sealing surface 34 of the annular member may thus be used to the user's advantage by enhancing adhesion of the facial seal to the user's face. In the alternative, if tackiness is not desired, the surface of the annular member 27 of facial seal 118 may be covered with a coating of powdered talc, silicone or similar biocompatible material.
As presently contemplated, the wall thickness of the peripheral wall portion 28 of the annular seal member 27 of the facial seals 18 and 118, excluding bosses 42, preferably ranges from about 0.2 to 0.3 inches. The weight of the facial seals 18, 118 depending on the size of mask bodies 12 with which they are used, ranges from about 1 to 2 ounces, a weight which has been discovered to be virtually unnoticeable to patients who have worn masks constructed according to the present invention in clinical tests. Furthermore, the fat-like resiliency qualities of the gel material which forms the annular member 27 creates in the wearer a comparatively cool and natural tactile sensation when the facial seal is in contact with the user's face. And, much like human fat tissue would perform, the facial seals 18, 118 effectively fill gaps and mold to the user's facial topography thereby minimizing leakage of gas supplied to the mask. Indeed, experimental testing has shown that respiratory masks fitted with facial seals in accordance with the present invention exhibit minimal gas leaks with headstrap tensile forces of 3 pounds or less, a value substantially less than related masks presently known in the art. The facial seals described herein thus enable respiratory masks to be worn by users for prolonged periods with little or no measurable discomfort. This phenomenon is especially important to users who must wear respiratory masks for extended periods such as patients undergoing respiratory therapy. Such individuals find that because of the comfort afforded by the facial seals 18, 118, their compliance with the respiratory treatment increases and the therapeutic benefits of the treatment are more fully realized.
As an alternative to the embodiments discussed above, it is also contemplated that a respiratory mask of the present invention may be constructed as a one-piece member rather than as a separate facial seal joined to a mask body. In such case, the respiratory mask may be fabricated as a unitary member formed from substances of increasingly softer durometers, as considered in a direction from that portion of the mask corresponding to the mask body toward that portion corresponding to the facial seal, such that the softest materials, comprising the previously discussed gel substance and possessing the resiliency characteristics described hereinabove, would constitute the seal or face-contacting portion of the annular member.
Although the invention has been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
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An improved flexible respiratory mask facial seal, as well a respiratory mask incorporating such seal. The facial seal comprises an annular member including a peripheral sidewall bounded by an inner end and an outer end generally opposite the inner end. The inner end is adapted for attachment to the shell or body portion of a respiratory mask and the outer end defines a contoured sealing surface adapted for confronting sealing engagement with a user's face. The annular member is formed of a gel substance possessing resilience characteristics corresponding to those of human fat tissue. Preferably, the annular member is encapsulated in a thin, pliable, membranous covering to enhance the durability and washability of the facial seal. Because the facial seal simulates the resiliency of human fat tissue, the user experiences the sensation of a natural substance against his skin when the mask is donned.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a machine for injection moulding of rubber products. In particular, it relates to a multi-station machine of high productivity.
[0002] In a machine for injection moulding of rubber, the mould receiving the material is always required to remain closed and under pressure over the whole time necessary for vulcanisation of the material itself.
[0003] Therefore, due to its own nature, the moulding unit has a production cycle that goes on for a period of time during which it is at a standstill, comprised between the moment of injection of the material into the mould and the moment of opening of the mould to withdraw the moulded article, which mould is then closed again to be brought back to the cycle starting conditions.
[0004] In order to increase productivity of a moulding machine it is possible to use a single feeding and injection unit which is brought to feed each of a number of moulds in succession. The solution appears to be particularly useful when a relatively long vulcanisation time is required, so as to avoid a correspondingly long time of inactivity of the machine.
[0005] Generally, these multi-station machines with a moving injector are complicated and bulky.
[0006] It is an aim of the present invention to provide a machine of high productivity with reduced bulkiness, adapted for production of rubber articles by injection.
SUMMARY OF THE INVENTION
[0007] In accordance with the invention, a machine for injection moulding of rubber products comprises a plurality of moulding units to be operated separately for carrying out a moulding cycle, in which the moulding units are mounted on a common support and each unit receives the rubber blend to be used in moulding through a duct branched off from a channel fed by a common injection unit, the branched-off feeding ducts being intercepted by a dispensing element moved step by step to sequentially open a predetermined number of the branched-off ducts corresponding to the moulding units that are driven to receive the rubber to be introduced into the mould for execution of moulding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For better explaining the features and advantages of the machine in accordance with the invention, an embodiment of same will be described hereinafter, by way of example, and illustrated in the accompanying drawings, in which:
[0009] [0009]FIG. 1 is an overall perspective view of the machine;
[0010] [0010]FIG. 2 is a longitudinal section of the machine portion comprising the moulding units;
[0011] [0011]FIG. 3 is a particular view in longitudinal section of one of the moulding units included in the machine.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Mounted on a base identified by 10 are rubber feeding and injection units, each unit, taken as a whole, being generally denoted at 12 and 13 and not described in detail because it is known by itself and of non-critical structure and configuration to the aims of the invention.
[0013] Advantageously, the feeding units 12 and 13 are of a known type and contemplate a piston-acting plasticization screw i.e. a screw provided with a rotatory thrust movement like an Archimedes' screw combined with the possibility of an axial piston-thrust movement.
[0014] The machine portion comprising the moulding unit, to which more specifically the invention relates, is generally identified by 11 .
[0015] Provision is made for a stationary core 20 around which an annular support element 21 carrying a plurality of moulding units 22 is fastened.
[0016] Mounted between the core 20 and support 21 is a cylindrical movable dispensing body 23 carried by a shaft 24 connected to a power unit 25 to operate a step-by-step rotation controlled by the dispenser 23 .
[0017] In more detail, through a general channel 26 , core 20 is reached by the rubber to be moulded, coming from injectors 12 and 13 which ensure a constant injection pressure in time, i.e. a continuous pressurised feeding.
[0018] This channel 26 branches off into radial ducts 27 . Advantageously, in the embodiment shown, the radial ducts are distributed in three ranks disposed in offset transverse planes of the core 20 , and denoted at 27 , 27 ′ and 27 ″ respectively, in order to avoid the useful solid core section being too much reduced due to the presence of a too great number of coplanar radial ducts, each terminating at a moulding unit 22 .
[0019] By distributing ducts 27 in different planes offset from each other, and correspondingly distributing the moulding units in different planes, the number of radial ducts 27 lying in the same transverse plane of core 20 is shared out so that the residual solid section is still sufficient to withstand the stresses resulting from the pressures in the ducts, as well as the external loads to which the core is submitted.
[0020] Disposed around the core 20 is the rotating dispensing element 23 carrying passageways 28 each of which is adapted to be arranged, for a predetermined angular portion of the dispenser, in alignment with a duct 27 formed in the core so as to dispose it in communication with a duct 29 constituting the extension thereof and feeding the rubber blend to a moulding unit 22 .
[0021] Obviously, in the dispenser a passageway 28 is provided for each offset rank on which ducts 27 and ducts 29 aligned therewith can be disposed.
[0022] One of the moulding units 22 is shown in more detail in FIG. 3.
[0023] Each moulding unit comprises a mould half 30 carried by the rod of a piston 31 moving in chamber 32 under the effect of a hydraulic fluid under pressure.
[0024] For movement of the double-acting piston 31 fittings 33 and 34 are provided for connection with a hydraulic drive circuit not shown.
[0025] The mould half 30 can be brought by piston 31 close to the mould half 35 to form the moulding cavity into which the blend can be introduced through an injection nozzle 36 . The blend is fed to the nozzle from a chamber 37 in which an injection metering piston 38 moves, which piston is operated to execute a stroke of an amount controlled by a piston 40 . Piston 40 is provided with an adjustable mechanical stop in order to define the stroke and consequently the displacement in chamber 37 .
[0026] As known, the moulding operation involves the steps of moving the mould halves close to each other, creating the vacuum to a predetermined value in the mould with the mould halves close to each other and the vacuum seal in a closed condition, injecting a metered blend amount, waiting for completion of the rubber vulcanisation, opening the mould, withdrawing the formed piece therefrom.
[0027] The whole operation takes a relatively long period of time and only during a small fraction of this time the blend-feeding duct 29 is required to be maintained in communication with the blend feeders 12 and 13 and substantially with the feeding channel 26 .
[0028] Theoretically, duration of this communication is exclusively required during the retraction step of piston 38 for carrying out a driven stroke in order to cause admission to chamber 37 of a metered blend amount.
[0029] Only during this feeding step the dispenser is required to be in such a position that ducts 27 and 29 related to the injection unit are brought into communication with each other, i.e. with a passageway 28 in alignment with them.
[0030] As a result, the moulding process of each unit can mostly take place during a period in which the dispenser element is disposed in such a manner that it can connect other moulding units with the blend feeding unit, to enable admission thereto of the metered blend amount required for a moulding operation.
[0031] A central control unit for the whole machine, herein not shown, which may consist of a computer-based control group, controls the different steps of the moulding operation of each unit and the step-by-step advancing means of the dispenser suitably in an appropriate phase so as to enable the dispenser to bring duct 29 related to each unit into communication with the respective duct 27 when admission of blend to the moulding unit is required.
[0032] Therefore, by controlling the moulding operations carried out by each unit according to a suitable sequential phase displacement, it is possible for a plurality of units, and possibly all units, to be simultaneously operational, so that the machine productivity is really a multiple of the productivity of each unit.
[0033] In the embodiment shown (FIG. 2) it is illustrated how the dispenser 22 brings two diametrically-opposite moulding units into communication with the feeding unit, considering as available for completion of the moulding operation of each unit the time imposed to the dispenser for rotating through 180°, in a sequence of 14 steps, so that the step of sequentially feeding with blend all the 28 moulding units radially mounted on support 21 should be carried out. Additional ducts are formed in core 20 and support 21 of the moulding unit 22 for circulation of a fluid for thermal conditioning of the parts concerned with the blend circulation, according to known technological requirements; therefore the related circuit will not be herein described in detail.
[0034] Due to the particular structure of the machine in accordance with the invention, the ducts holding the thermal-conditioning fluid can follow a path extending in core 20 and advantageously going on in a direct way into support 21 and then into the body of units 22 .
[0035] Accomplishment of the above described machine is to be considered by way of example only and many modifications can be done without departing from the scope of the invention.
[0036] In particular, the dispensing element can take a great number of shapes.
[0037] Arrangement of the different moulding units in axially spaced apart ranks enables also ducts 27 to be disposed in spaced apart ranks in the core, so that transverse core sections too much impoverished in material do not exist therein.
[0038] However, other construction solutions can be adopted to this aim. For example, channel 26 can feed a single annular duct within core 20 and close to the periphery thereof, so as to minimise the length of ducts 27 and the consequent absence of material at the section in which they are formed. In this way, arrangement of all ducts 27 in a single plane transverse to the core could be provided and, as a result, the circumferential alignment of all moulding units.
[0039] Generally, the dispensing device may have any configuration provided it fulfils the function of selectively connecting the predetermined number of moulding units to the blend feeding unit for each of the positions that the dispensing device is driven to take step by step.
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The present invention relates to a machine for injection molding of rubber products, comprising a plurality of molding units to be operated separately for carrying out a molding cycle. The molding units are mounted on a common support and each unit receives the rubber blend to be used in molding through a duct branched off from a channel fed by a common injection unit. The branched-off feeding ducts of the units are intercepted by a dispensing element moved step by step to sequentially open a predetermined number of the branched-off ducts, so that the corresponding molding units are driven to receive the rubber to be introduced into the mold for execution of molding.
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FIELD OF THE INVENTION
This invention relates generally to a system and method of supplying batteries with fluid, particularly to a system and method for supplying rechargeable, electrolyte starved metal-air batteries with water and electrolyte, and more particularly to a system and method for supplying electrolyte to rechargeable electrolyte starved zinc-air cells suitable for use in traction batteries for electric vehicles.
BACKGROUND OF THE INVENTION
Metal-air batteries, such as zinc-air batteries, offer the advantage of very high energy densities (up to 300 Wh/kg) over known conventional batteries, like lead-acid batteries, used to power electric vehicles. This is possible because, unlike a conventional battery cell that is comprised of two metal electrodes, a metal-air battery cell has only one metal electrode and a light-weight air cathode that absorbs air. For example, in a zinc-air cell, oxygen in the air is converted to hydroxyl ions, which oxidize the zinc anode, and water and electrons are released to produce electricity. The high energy density of metal-air batteries, like zinc-air batteries, translates into long operating range for electric vehicles, which in combination with low commercial production costs and a high degree of safety for both the environment and the consumer, offer significant advantages over conventional batteries for use in large consumer applications, like electric vehicles.
Experimental rechargeable metal-air batteries, like zinc-air batteries, have been built for use in electric vehicles and these batteries use a water-based electrolyte to convert oxygen to hydroxyl ions, which react with the zinc, to produce electricity. Because the air cathode of a metal-air cell passes water molecules as easily as oxygen molecules (due to similar molecular size and polarization), water loss is often experienced from the electrolyte if the ambient humidity is less than the equilibrium relative humidity value for the metal-air cell. This drying out of the cell may cause failure. Additionally, heat produced by the electrolytic reaction tends to increase water loss from the cell.
Batteries are sized to match the application in which the particular battery will be used. High-power applications, like powering traction motors in electric vehicles, tend to use large batteries including hundreds of individual metal-air cells electrically connected within the battery. Smaller batteries such as those used in consumer electronic devices can often use smaller batteries having fewer metal-air cells. The larger the battery, the more heat the battery will produce in operation. When larger quantities of heat are generated, more water evaporates from the electrolyte within the battery. Consequently, the electrolyte often must be replenished, especially in larger batteries, or the battery may fail. An automatic system to monitor cell performance and to add electrolyte to the battery when needed is desired in order to make larger batteries, such as traction batteries, easier to maintain and operate.
In addition to water loss from the electrolyte, there are other problems associated with electrolyte that interfere with performance of a metal-air battery. Carbonation of the electrolyte, due to a reaction of carbon dioxide with certain cell components and the electrolyte, interferes with the electrochemical reaction. In a zinc-air battery, uneven distribution of the electrolyte near the zinc anode, resulting in local concentration gradients of electrolyte, contribute to dendrites of zinc growing from the zinc anode to the air cathode during cycling of the cell. Eventually, dendrite formation may cause the cell to short out. Additionally, leakage of excess electrolyte can cause cell failure and corrosion of cell surroundings.
External replenishment methods and systems for batteries with a limited number of cells are known, wherein electrolyte is manually added to a common solution tank and is dispensed to the cells via ports and/or ducts under vacuum-induced pressure. U.S. Pat. No. 3,483,042 to Hulse, U.S. Pat. No. 3,630,786 to Ibaraki, et al., and U.S. Pat. No. 3,892,595 to Bell, et al. disclose such one-time manual methods and devices for filling battery cells with electrolyte.
U.S. Pat. No. 4,702,972 to Matsumoto discloses an electrolyte replenishing system specifically for a laminated type fuel cell wherein excess electrolyte is collected and recycled by means of a pump. Matsumoto '972 provides a system for continuous replenishment of electrolyte, but is specifically designed, for use with a laminated type fuel cell and is not automated to provide specific amounts of electrolyte at specific time intervals.
Therefore, a distributing system is desired that can satisfactorily replenish water and/or electrolyte loss experienced by a battery used in large consumer applications, like electric vehicles, and can effectively control electrolyte levels within the battery, such that only enough electrolyte as is needed for operation of the battery is provided on a periodic, automatic basis.
SUMMARY OF THE INVENTION
The present invention provides an electrolyte distributing system and method for providing electrolyte to an electrolyte starved battery in a preplanned sequence. The system preferably includes or is associated with an electrolyte reservoir and feed system, a control system for monitoring the performance of each cell or group of cells in a battery, and an apparatus for controlling the amount of electrolyte supplied to each cell or group of cells as determined by the control system.
In accordance with one aspect of the invention, a method of providing electrolyte to an electrolyte starved battery includes the steps of supplying electrolyte from a source to a dispenser, and rotating the dispenser to dispense the electrolyte from the dispenser sequentially to each of a plurality of electrolyte inputs in the electrolyte starved battery.
In accordance with another aspect of the invention, an electrolyte dispensing device includes a rotating dispenser and stationary manifold, the rotating dispenser including a first electrolyte passageway leading from a dispenser input of the rotating dispenser to a dispenser output of the rotating dispenser confronting the manifold, and the stationary manifold having a number of electrolyte passageways, each passageway having a manifold input confronting the rotating dispenser and a manifold output, the manifold inputs being arranged along a circular path circumscribed by the dispenser output as the rotating dispenser rotates.
In accordance with another aspect of the invention, a self-distributing electrolyte starved metal-air battery includes a dispensing device including an apparatus for selectively coupling a supply of electrolyte to one of a plurality of feed lines, and a plurality of metal-air cells, each including a metal anode, an air cathode, an anode electrolyte absorber adjacent said anode, a cathode electrolyte absorber adjacent said cathode, a separator separating said electrolyte absorbers, an electrolyte input coupled to one of the plurality of feed lines for supplying electrolyte to the absorbers at a supply side of the cell and a drain for draining excess electrolyte from said electrolyte absorbers at a drain side of the cell.
In accordance with a further aspect of the invention, a method of providing electrolyte to an electrolyte starved battery includes the steps of supplying electrolyte from a source to a dispenser, and dispensing the electrolyte from the dispenser in a preplanned sequence to each of a plurality of electrolyte inputs in the electrolyte starved battery.
In accordance with a still further aspect of the invention, an electrolyte dispensing device includes a supply valve for selectively coupling a supply of electrolyte to a manifold, a plurality of feed valves, each feed valve selectively coupling the manifold to the electrolyte input of at least one battery cell, and a processor for controlling the supply valve and the feed valves to generally sequentially provide electrolyte to the battery cells.
The foregoing and other features of the invention are hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed. It will be appreciated that the scope of the invention is to be determined by the claims and the equivalents thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
In the annexed figures:
FIG. 1 is a schematic illustration of a battery system including one embodiment of an electrolyte distributing system used with an electrolyte starved zinc-air battery;
FIG. 2 is a top view of an electrolyte distributing system;
FIG. 3 is a side view of an electrolyte distributing system;
FIG. 4 is a cross-sectional view of the electrolyte distributing system taken along line 4--4 in FIG. 2;
FIG. 5 is a top view of the rotating dispenser of the electrolyte distributing system;
FIG. 6 is a top view of the stationary manifold of the electrolyte distributing system;
FIG. 7 is a cross-sectional view of an electrolyte starved zinc-air cell; and
FIG. 8 is a schematic illustration of a battery system including an alternate electrolyte distributing system used with an electrolyte starved zinc-air battery.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is illustrated schematically a battery system 10 including an electrolyte starved battery 12 and an electrolyte distributing system 14 in accordance with the present invention. The electrolyte distributing system 14 of the present invention is described herein with reference to an exemplary use with an electrolyte starved metal-air cell battery, and more particularly a zinc-air cell battery. One such metal-air cell battery is disclosed in co-pending U.S. patent application Ser. No. 08/361,778 filed Dec. 22, 1994, entitled "Electrolyte Starved Metal-Air Battery", and naming Michael C. Cheiky as inventor; the disclosure of which is incorporated by this reference. However, it will be appreciated that the described battery is merely exemplary and that the electrolyte distributing system 14 may be used to supply electrolyte to any battery requiring the periodic distribution of electrolyte to cells within the battery.
In addition to the metal-air battery 12 and the electrolyte distributing system 14, the battery system 10 further includes an electrolyte collecting tank 16, a pump 18, an accumulator tank 20, a pressure sensor 22, solenoid valves 24 and 25 and switching element 26 for controlling operation of the pump and flow of electrolyte from the accumulator to the electrolyte distributing system, respectively. Control of the valves 24 and 25, switching element 26 and electrolyte distributing system 14 is preferably performed by a microprocessor 27. The solenoid valves 24 and 25 control the flow of electrolyte and "scrubbed" air (air in which the carbon dioxide has been substantially removed), respectively, to the electrolyte distributing system 14.
The exemplary metal-air battery 12 includes a number of rechargeable, electrolyte starved zinc-air cells 28 contained within a battery housing 30. Preferably, the zinc-air cells 28 are stacked generally vertically, with each cell inclined approximately at a 6° to 10° angle to horizontal. At the elevated end 31 of each cell 28 is an electrolyte injection port 32 through which electrolyte is provided to the cell from the electrolyte distributing system 14. At the lower end 34 of each cell 28 are one or more drains 36 for draining excess electrolyte from each cell to a common drain 38. The excess electrolyte drained from each cell is collected, recycled and returned to the zinc-air cells 28 through the electrolyte collecting tank 16, the pump 18, the electrolyte accumulator 20 and the electrolyte distributing system 14. Preferably the distributing system 14 distributes electrolyte to the cells 28 of the battery 12 individually and sequentially although the distributing system may distribute electrolyte to groups of cells at the same electrical potential.
One embodiment of an electrolyte distributing system 14 is shown in a top view and in an elevation view in FIGS. 2 and 3, respectively, with FIG. 4 illustrating a cross-sectional view of the system taken generally along line 4--4 in FIG. 2. The electrolyte distributing system 14 includes a rotating electrolyte dispenser 40 and a stationary manifold 42 which cooperate to distribute electrolyte sequentially to the several zinc-air cells 28 of the battery 12. The stationary manifold 42 and rotational dispenser 40 are preferably disk shape with the stationary manifold affixed to a frame 44.
The rotating dispenser 40 and stationary manifold 42 are provided with flat, smooth confronting surfaces 46 and 48, respectively, to allow for free rotational movement of the surfaces relative to one another and to provide a fluid seal between the surfaces. The rotating dispenser 40, as seen in FIGS. 4 and 5, includes an electrolyte input 50 concentric with the axis of rotation of the dispenser and a fluid inlet passageway 52. An interior electrolyte passage 54 leads from the electrolyte input 50 to a dispenser outlet 56 which opens to the lower surface 46 of the rotating dispenser 40 confronting the manifold 42. The dispenser output 56 is preferably somewhat elongated in a radial direction to provide a generally oval shape. A rotating joint 58 is provided to couple the dispenser input 50 to a stationary electrolyte supply line 60 (see FIGS. 1 and 4).
As seen in FIG. 6, the stationary manifold 42 includes a number of manifold inputs 62 radially offset from the center of the manifold along a path circumscribed by the dispenser outlet 56 of the rotating dispenser 40 as it rotates relative to the stationary manifold 42. There is preferably a separate manifold input 62 corresponding to each cell in the battery 14, although a single manifold input may be used for a grouping of cells in the battery at the same electrical potential. The manifold inputs 62 are preferably equally spaced around the manifold 42. Consequently, in the instant example with a battery 14 having 120 metal-air cells therein, there would be preferably 120 manifold inputs 62 corresponding to individual cells and one or more additional inputs provided as flushing ports equally spaced around the manifold 42. An interior electrolyte passage 64 extends radially outwardly from each manifold input 62 to emerge at a separate manifold output 66 along the periphery of the manifold 42. Each manifold output 66 is coupled to a line 68 which supplies electrolyte from the manifold output to a corresponding input 32 of a cell 28 or coupled to a line 67 through which electrolyte can be routed to the collecting tank 16 bypassing the cells 28.
As noted above, one or more of the manifold inputs 62 and outputs 66 may serve as flushing ports in which case they would be fluidly coupled to the electrolyte collecting tank 16 through lines 67 (see FIG. 1). In this manner, it is possible to flush electrolyte which has become overly diluted or concentrated as a result of the system sitting idle for an extended period of time from the lines of the system (i.e., lines 112) back to the collecting tank 16 so that well-mixed electrolyte can be used to replenish the cells 28. The flushing ports may also be used to determine if the system is working properly or to attempt to clear the lines in the system.
Preferably, to minimize the risk of shunt currents between cells 28 in the battery 12, the manifold inputs 62 corresponding to cells at significantly different potential differences are adequately separated so that the electrolyte distributed through a feed line 68 to a cell at one potential can sufficiently drain before electrolyte is distributed to a feed line corresponding to a cell at a significantly different potential. For example, the cells 28 at the greatest potential difference can be connected to manifold outputs 66 located substantially 180 degrees apart on the manifold 42, with the potential difference between cells connected to adjacent manifold outputs minimized. To explain, consider manifold output 66a as being connected to the cell 28 at the lowest potential in the battery and the manifold output 66z as connected to the cell at the highest potential and the manifold outputs 66b-66e being at progressively higher potentials as their respective reference letters near "z". The manifold outputs 66 would then be allocated to cells 28 as represented in FIG. 6. Manifold output 66a would have manifold outputs 66b and 66c to either side, with manifold output 66d nearest manifold output 66b and manifold output 66e nearest manifold output 66c and so on around the manifold, with the manifold output connected to the cell at the highest potential, in this example manifold output 66z, diametrically opposed to the manifold output connected to the cell at the lowest potential, manifold output 66a. In this manner, the potential difference between cells connected to adjacent manifold outputs 66 around the manifold 42 is minimized and the possibility of shunt currents is decreased throughout an electrolyte distribution cycle.
Other factors which increase the resistance of the system to shunt currents include increasing the physical length of the electrolyte feed lines 68, maximizing electrical isolation by distributing electrolyte to one cell at a time, using electrically non-conductive materials where possible, and using an air blow-down, discussed below, to clear the electrolyte feed lines before and after an electrolyte feeding cycle.
In operation, the accumulator 20 provides electrolyte to the electrolyte distributing system 14 for replenishment of the cells 28 through the valve 24 along the stationary line 60 connected to the rotating joint 58. The electrolyte flows through the rotating joint 58 through the fluid passageway 52 and the dispenser input 50 to the dispenser output 56 through the interior electrolyte dispensing passage 54. As the rotating dispenser 40 rotates, the dispenser outlet 56 follows a circular path passing over each manifold input 62. Since the confronting surfaces 46 and 48 of the rotating dispenser 40 and stationary manifold 42, respectively, are flat and the confronting surface 46 of the rotating dispenser is biased against the confronting surface 48 of the stationary manifold, when the dispenser outlet 56 is at a point between manifold inputs 62, flow from the dispenser outlet 56 is blocked. When the dispenser outlet 56 is generally aligned above a manifold input 62, electrolyte will flow from the dispenser outlet 56 through a manifold input 62, the internal electrolyte passage 64 and from the manifold 42 through the manifold output 66 to a corresponding cell 28 over a feed line 68. By connecting one cell or parallel strings of cells at a single electrical potential to the feed electrolyte at a single time, harmful shunt currents across the battery pack through the electrically conductive electrolyte are reduced. The confronting surface 46 of the rotating dispenser 40 may also be provided with leading and trailing vents, respectively located before and after the dispenser output 56 relative to the direction of rotation of the rotating dispenser, to allow the electrolyte flow path to the cells 28 to breathe and to therefore minimize air pockets which might obstruct the flow of electrolyte to a cell.
To minimize leakage between the confronting surfaces 46 and 48 of the rotating dispenser 40 and stationary manifold 42, the rotating dispenser is biased against the stationary manifold by biasing elements 86 disposed around the rotating dispenser. The biasing elements 86 include a leaf spring 88 mounted to the rotating dispenser 40 and a spring 90 positioned between the rotating dispenser and the cantilevered portion of the leaf spring.
Rotation of the rotating dispenser 40 is accomplished by a chain drive mechanism 70 and motor 72 (See FIGS. 2 and 4). A sprocket 74 is positioned above the rotating dispenser 40 by spacers 76. The sprocket 74 is engaged with a chain 78 which is in turn engaged with a suitable gear 80 driven by the motor 72. A tensioning mechanism 82 may be provided to allow adjustment of the chain tension or to maintain constant tension. The sprocket 74 preferably has a relatively large diameter to distribute force over a large portion of the rotating dispenser 40. The rotational movement and rotational speed of the motor 72 and chain drive 78 are preferably controlled by the microprocessor 27 so that the speed that the rotating dispenser 40 rotates and the rotational position and dwell time of the rotational dispenser can be controlled.
Disposed adjacent the rotating dispenser 40 and stationary manifold 42 is an optical encoder 84 which communicates to the microprocessor 27 its location vis-a-vis an input of the stationary manifold. Based on the parameters of its programming, the microprocessor 27 turns the valve 24 on for a specified length of time, for example two seconds, allowing fluid to flow from the accumulator tank 20, via the rotating dispenser 40 and stationary manifold 42, to the cell or groups of cells to be replenished with electrolyte. After the specified length of time has elapsed, the microprocessor 27 turns the valve 24 off, shutting off the flow of fluid from the accumulator tank 20. The microprocessor 27 then turns on the motor 72 for a specified length of time, which drives and thus rotates the rotating dispenser 40 through the chain 78 and sprocket 74 to align the dispenser outlet 56 with the next manifold input 62. The encoder 84 then communicates the rotational position of the rotational dispenser 40 to the microprocessor 27 again and the entire sequence of steps is repeated. In some instances the microprocessor 27 may also cause electrolyte to be directed through the rotating dispenser 40 through a flushing port in the stationary manifold 42 for a desired period of time to flush electrolyte through the system. Between successive electrolyte replenishing cycles, the system may also blow scrubbed air through the rotating dispenser 40 and stationary manifold 42 to the cells 28 to remove remaining electrolyte and any electrolyte film from the feed lines 68. This is accomplished by the microprocessor 27 by closing solenoid valve 24, and opening solenoid valve 25 to supply scrubbed air from the air input 69 to the supply line 60 coupled to the rotating dispenser 40.
Hydraulic head, which is a function of the vertical distance between the distributing, system and the cell, or groups of cells, being fed, affects the uniformity of fluid flowing to the cell(s) such that the cell(s) with greater vertical distance from the distributing system will experience greater fluid flow provided all other factors, like number or length of feedings, are equal. To counter this effect and to provide for uniform flow of fluid to all cells, the length and/or number of fluid feedings can be adjusted. Differing dwell times and/or number of fluid feedings can be controlled by programming the microprocessor 27 such that cells with a closer vertical distance can have longer feed times. The microprocessor 27 can also be programmed to monitor cells 28 for leakage and to dispense more electrolyte to these cells. Additionally, mechanical deficiencies of the distributing system 14, like different output sizes in the perimeter of the stationary manifold, which result in cells receiving differing amounts of electrolyte can be corrected by adjusting the dwell time that the rotating dispenser 40 feeds a particular cell 28.
The components of the electrolyte distributing system 14 which come into contact with the electrolyte, for example, the rotating dispenser 40 and the stationary manifold 42, are preferably constructed of a material which is not adversely affected by the electrolyte and any caustic action it may have. Such components are preferably constructed of at least one polyolefin, preferably polypropylene as it is light weight, self lubricating and has anti-corrosion and anti-seize properties. Other components of the electrolyte distributing system 14 are preferably also constructed of polypropylene or a similar plastic to minimize the weight of the system.
As noted above, the exemplary battery 12 may include a number of metal-air cells, for example a zinc-air cell 28 as is shown in cross-section in FIG. 7. The cell 28 includes an anode 92, a cathode 94, at least two electrolyte absorbers 96 and 98 and a separator 100 encased and maintained in place by a casing 102. The anode 92 is located in the bottom of the casing 102 and is made preferably of a zinc paste. Located in the cell 78 opposite the zinc anode 92 is the air cathode 94. The air cathode 94 is positioned immediately below openings or vents 104 in the top of the casing 102 to permit air to contact and flow across the air cathode. The air cathode 94 is preferably in the form of an air permeable woven or non-woven carbon membrane or similar material with a high affinity for oxygen.
Disposed between the zinc anode 92 and the air cathode 94 are the electrolyte absorbers 96 and 98 which supply electrolyte to the zinc anode and air cathode, respectively. The separator 100 separates the anode electrolyte absorber 96 from the cathode electrolyte absorber 98 and rejects the flow of zinc ions toward the air cathode 94 from the zinc anode 92.
Each zinc-air cell 28, or each group of cells at the same electrical potential, includes an electrolyte injector port 32 located near the top of the cell and at the end 31 of the cell which is elevated (hereinafter the supply side) when the cell is arranged with other cells in the battery 10. Each electrolyte injector port 32 is connected to a separate manifold output 66 through a feed line 68 (shown in FIGS. 1 and 4). Located at the other end 34 of the each cell 28 (hereinafter the drain side) is one or more electrolyte drains 36 for removing excess electrolyte from the cell. A reservoir 106 is provided between the injector port 32 and the electrolyte absorbers for storing and slowly dispersing electrolyte to the cathode electrolyte absorber 98 and anode electrolyte absorber 96 for supply to the air cathode 94 and zinc anode 92, respectively.
Referring back to FIG. 1, during operation of the electrolyte starved zinc-air battery 12, the excess electrolyte is drained from each cell 28 via the drain 36 and is collected in the collecting tank 16 through drain line 38. The drained excess electrolyte is thicker than the electrolyte supplied to the cells due to carbonation of the electrolyte and water loss from the electrolyte. Preferably, carbonation is filtered out of the excess electrolyte by passing the electrolyte immediately upon drainage through a carbonation filter 108 attached horizontally across the collecting tank 16. Subsequently, the filtered electrolyte is rehydrated by, preferably, adding diluted electrolyte from the storage tank 110 to the collecting tank 16, although pure water can be used. Diluted electrolyte is preferable to pure water because its freezing point is below 0° F. compared to a freezing point of 32° F. for water. The electrolyte is then pumped to the accumulator tank 20 by the pump 18 over the return line 112. A one-way valve 114 is attached to the return line 112, between the pump 18 and the collecting tank 16, to prevent electrolyte from backing up into the collecting tank 16.
The accumulator tank 20 holds the electrolyte until a certain pressure is detected by the pressure sensor 22, for example 30 psi. When electrolyte in the accumulator tank 20 reaches this pressure, the pressure switch 26 is triggered shutting off the pump 18. The flow of electrolyte stored in the accumulator tank 20 to the dispensing system 14 is controlled by a solenoid valve 24 which is operated in accordance with the electrolyte requirements of the dispensing system as determined by the microprocessor 27. Once the pressure of the electrolyte supplied by the accumulator tank 20 decreases to a certain pressure, for example 15 psi, the pressure switch 26 is again triggered, which activates the pump 18. The cycle is continually repeated. Supplying electrolyte under pressure counters the effect of hydraulic head, which affects the uniformity of the amount of electrolyte flowing to each cell such that, the farther the vertical distance between the electrolyte dispensing system 14 and the cell 28 being fed, the greater the amount of electrolyte dispensed, all other factors, like number or length of feedings, being equal.
The electrolyte supplied to each cell 28 via the feed lines 68 and electrolyte injector port 32 is slowly dispersed within the cell of the electrolyte absorbers 96 and 98 (FIG. 7). Due to the inclination of the cells 28, at about a 6° to 10° angle to horizontal, and the hydrophilic nature of the electrolyte absorbers 96 and 98, the electrolyte is absorbed across substantially the entire length of each electrolyte absorber from the elevated side 31 of the cells 28, to the lower side 34 of the cells. Any excess electrolyte not absorbed by the electrolyte absorbers 96 and 98, collectively drains from the cells 28 at the drains 36 into the collecting tank 16 through the drain line 38. The slight incline also prevents percolation and venting of the electrolyte up through the input on the elevated side each cell. The recycling phase of the excess electrolyte is then begun again.
During a blowing operation which may take place between successive electrolyte replenishing cycles to clear electrolyte from the feed lines 68, the solenoid valve 24 is closed while the solenoid valve 25 is opened to couple the air supply 116 to the electrolyte distributing system 14 through the supply line 60. The air supply 116 is preferably at a pressure about 5 psig above the pressure of the electrolyte supply line 112.
A battery system 10' employing an alternate embodiment of an electrolyte distributing system 14' is shown in FIG. 8. In addition to the electrolyte distributing system 14', the battery system 10' includes an electrolyte collecting tank 16, a pump 18, an accumulator tank 20, solenoid valves 24 and 25 and a combined pressure sensor and switching element (pressure valve) 120 for controlling operation of the pump. Control of the solenoid valves 24 and 25 and the electrolyte distributing system 14' is performed by a microprocessor 27. The scrubbed air supply 69 is shown in more detail than in FIG. 1 and includes a compressor 122, a receiver 124 and a pressure valve 126. Scrubbed air is supplied from the collecting tank 16 over line 69 to the compressor where the pressure of the air is increased to and stored at approximately 5 psig above the pressure of the electrolyte in supply line 112. The scrubbed air is further supplied to the distributing system 14' over line 60 when the solenoid valve 25 couples lines 69 and 60 as controlled by the microprocessor 27.
The distributing system 14' employs a number of solenoid valves 130, each controllably coupling supply line manifold 132, which is supplied electrolyte or scrubbed air from the supply line 60, to a feed line 68 to provide electrolyte or scrubbed air to a cell 28. One or more solenoid valves 134 are also included as flushing ports coupling the manifold supply line 132 to a flushing line 67 for routing electrolyte directly to the collecting tank 16.
In FIG. 8 the battery 12 is illustrated as two separate banks 140 of cells 28 to indicate one instance where a single feed line 68 and solenoid valve 130 may feed electrolyte to a group of cells at the same electric potential. In such an instance the feed line 68 would branch into separate feed lines 68a and 68b which would be routed to the inputs (not shown) of cells 28a and 28b, respectively, in each cell bank 140 at approximately the same potential.
In operation, during a replenishing cycle, the processor 27 typically sequentially instructs each of the solenoid valves 130 to couple a feed line 68 to the supply manifold line 130 to establish a path between a cell 28 and the supply line 60. The processor 27 then instructs one of the solenoid supply valves 24 or 25 to supply electrolyte or scrubbed air to the supply line 60 for flow to a cell 28 for a desired period of time. The time may be adjusted in accordance with the specific electrolyte requirements of a cell 28. For instance, if through monitoring of the cell voltage between the anode 92 and cathode 94 of a cell 28, it is determined that the voltage is lower than optimal, the processor 27 may increase the duration of time that the solenoid valve 24 is pulsed open to increase the amount of electrolyte supplied to the cell. It is also possible to control the supply of electrolyte to the cell by the controlling the individual solenoid valves 132 while leaving supply valves 24 or 25 open, but as the solenoids 130 may have a slower response time than the solenoid valves 24 and 25 because of the possibility of employing valves with reduced size and power requirements for the valves 130, it may be beneficial to pulse the more responsive solenoid valves 24 or 25 to more accurately control fluid flow to the cell. Similarly, electrolyte is flushed through the system 10 by opening solenoid valve 134 to couple the flush line 67 to the supply line 60 and then opening supply valve 24 for the desired period of time.
Between successive replenishing cycles, air may be blown through the feed lines 68 in the same manner in which electrolyte was added to the cells, with the exception that the supply valve 25 is pulsed on and off to deliver air to the feed lines coupled to the supply line 60 by respective solenoid valves 130.
While a preferred example of the invention has been shown and described, numerous variations and alternate examples will occur to those skilled in the art, without departing from the spirit and scope of the present invention. Accordingly, it is intended that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein. It is to be realized that only a preferred example of the invention has been described and that numerous substitutions, modifications and alterations are permissible without departing from the spirit and scope of the invention as defined in the following claims. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
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A method of providing electrolyte to an electrolyte starved battery includes the steps of supplying electrolyte from a source to a dispenser and dispensing the electrolyte from the dispenser in a preplanned sequence to each of a number of electrolyte inputs in the electrolyte starved battery. Related devices for accomplishing such a method are also disclosed.
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PRIORITY CLAIM
The present application claims benefit under 35 USC Section 119(e) of U.S. Provisional Patent Application Ser. No. 61/050,019 filed on 2 May 2008. The present application is based on and claims priority from this application, the disclosure of which is expressly incorporated herein by reference.
BACKGROUND
The present invention relates to a device adapted for use on the rear portion of an off-highway or construction vehicle to improve the unrolling of geotextile materials as commonly used in road-beds, landscaping, retention walls, pond-lining, and the like. And, more specifically, the present invention relates to a device that couples to a conveyered material placement vehicle to simultaneously and continuously dispense fabric from a roll as an aggregate is placed on top of the dispensed fabric.
Certain construction techniques for roadbeds, drainage ditches, man-made ponds and other landscaping needs require a cloth or fabric liner layer to be placed on the newly prepared and compacted soil. This cloth or fabric liner typically arrives at the construction site in large roles varying from about 3-feet to about 15-feet in width and (unfurled) having lengths of 300 feet or more for landscape rolls and about 13-feet wide or about 15-feet wide for road-bed fabric rolls, for example.
Fabric rolls used in road construction, landscaping and the like are generally known as geotextiles and are defined by the American Society for Testing and Materials (ASTM) as any permeable textile material used with foundation, soil, rock, earth as an integral part of a construction project, structure, or system and may be synthetic or natural fibers, or both. Geomembranes, also used in similar applications, are continuous membrane-type liners or barriers that have low permeability to control migration of fluid and restrict fluid flow.
In the road construction industry there are essentially four primary uses for geotextiles: separation, drainage, filtration, and reinforcement. However, most often geotextiles are used for stabilizing roads through separation and drainage. Stabilization results from the geotextile acting as a barrier to migration of fines in the subgrade to the base layer (aggregate layer), while simultaneously permitting water to migrate from the base layer to the subgrade or laterally away from the roadbed. Migration of fines is highly undesirable because it weakens the road structure.
Geotextiles are well suited for temporary road construction, particularly in environmentally sensitive areas where a biodegradable woven jute geotextile can be used. Geotextiles are economical for temporary road construction, such as construction roads in isolated areas as are needed to install power grid infrastructure, wind-turbine power generations, or remote logging roads, for example.
Such roads, for example, use a crushed aggregate layer on top of native subgrade material. A geotextile serves as a separation layer between the subgrade and the aggregate, preventing intermixing of the two layers. Intermixing occurs (absent the geotextile layer) from pressure exerted on the road from vehicles, the downward and laterally moving load creates a pump-like affect that draws fines in the subgrade upward, intermixing in the aggregate layer. This affect becomes more dramatic when there is water migration as well.
Thus, proper selection and installation of a suitable geotextile is vitally important in road construction. The installation method for geotextiles (or fabric rolls), as generally known in the art, requires shaping the roadway subgrade, rolling the fabric down the road one lane per roll, and if windy, weight the sides of the unrolled fabric with shovels full of gravel or use spikes or staples to pin the fabric down. Then, dump and spread the gravel or base course material using normal methods with an end dump truck (or belly-dump or side-dump trucks)—but making certain to avoid driving onto the geotextile with any equipment other than rubber-tired vehicles operating over a solid sub-grade in a straight line with no turns and a vehicle speed of no more than seven miles per hour or otherwise risking a puncture or tear, damaging the fabric and making it less suitable for its intended use.
Currently, the tools and methods to unroll these large fabric rolls include a hanger bar coupled to the rear of a vehicle, such as a dump truck (belly, side, or end) or a front-end loader using the bucket to suspend a roller bar and reversing to unroll the material. The hanger bar supports a roll bar adapted to slideably receive a roll of material. Then, several workers unroll a portion of the roll, stand on it, pin it, or manually shovel some aggregate (e.g. gravel) on the roll to hold it in place. Next, the vehicle advances and unrolls the fabric as the vehicle travels. To hold the fabric in place, the army of workers shovels aggregate, or use spikes to pin the fabric to the sub-grade. Only after the fabric is fully installed, then a second aggregate delivery truck (dump truck), backs to the fabric—to avoid driving on the fabric, which could rip or tear the fragile material—and then dumps the aggregate. Next, a third vehicle (bull-dozer) distributes the piled aggregate on top of the fabric. This is a tedious and time-consuming procedure that must be repeated for the entire length of the road, which could be several dozens of miles.
The state-of-the-art method of installing fabric sheets, according to the “North Carolina Forestry BMP Manual”, Appendix 4 at page 222 of 243 (amended 2006) publication date unknown, includes shaping the roadway and establishing the crown; rolling the fabric, weight the sides and end of the unrolled fabric with shovels full of gravel, or use spikes to pin the fabric down. This method, however, has certain drawbacks. One drawback includes puncturing the fabric with spikes or staples to pin the material: it is undesirable to puncture the fabric as this causes rips and tears in the sheet, and the punctures themselves enable the base layer to intermix with the aggregate layer, which weakens the roadbed. Manpower cost associated with shoveling aggregate on top of the unrolled sheet to weight it down is yet another drawback of this known method.
Certain devices are known to facilitate the laying of paving fabric along a roadbed. For example, U.S. Pat. No. 4,456,399 issued on 26 Jun. 1984 to Conover describes an apparatus for laying paving fabric comprising a core support member of an adjustable length for supporting a roll of paving fabric on a vehicle, a tension applying apparatus secured in the proximity of the fabric roll to remove wrinkles from the web prior to the application to the roadbed, and a broom apparatus for facilitating adherence of the web to the roadbed and a guard for the broom for reducing wrinkling of the fabric.
Yet, there remains a need for improved methods and devices that improve the installation of geotextiles and similar fabric rolls, particularly on temporary road-bed projects. Such tools and methods should minimize worker exposure to injury, reduce manpower required, and reduce expense of installation through time and manpower efficiencies. An improved device and method is needed that enables the unrolling of the fabric roll without requiring spikes to penetrate the fabric to pin the roll in place (as needed, for example, in windy conditions). It would further be desired to have a tool and method that improves efficiencies by combining the rolling of the fabric with the delivery of the aggregate. Such a device, in addition, should be easy to transport to the job site on existing vehicles. Further, such an improved device should be easy to assemble and disassemble by one person.
SUMMARY OF THE INVENTION
The present invention includes improved devices and methods to simultaneously unroll geotextile fabric and place aggregate on top, without requiring spikes or staples to pin the fabric in place.
In one preferred embodiment, the present invention consists of a conveyered material placement vehicle adapted to hold multiple widths and lengths of road bedding cloth or landscape cloth. The vehicle includes two receiver hitches welded, attached or otherwise coupled on opposite sides of the rear bumper, approximately seven feet between each other. The pair of receiver hitches slideably receive a corresponding square steel tube or round pipe having a through hole at one end, which enables the retaining pin of the receiver hitch to pass through the receiver hitch and the end of the steel tube when inserted in the hitch. The pair of horizontally disposed steel tubes protrude generally perpendicular from the rear bumper of the vehicle and serve as mounting arms for an approximately 16-foot length of square steel tubing (or similarly sized round pipe of about 2-inches in diameter) that serves as the hanger bar, which arranges generally parallel to the rear bumper of the vehicle and shares the vehicles centerline, but is offset from the rear bumper by a length determined by the pair of steel tubes, which are of a length to clear the device from the operation of the conveyered aggregate delivery apparatus mounted to the rear portion of the vehicle.
The hanger bar includes a pair of end caps and half links are welded to the end caps, and a pair of eye-loops are additionally welded to this bar. A segment of about 2-feet in length of chain hangs from each end cap half links. This pair of chain segments supports a roller bar, which has a round cross section and adapts to suspend a fabric roll and allows the roll to rotate freely on the bar. The roller bar is further adapted to receive varying lengths of fabric rolls by means of several positioned through-holes, which adapt to receive lock-pins. Thus, a pair of locking plates can be positioned on the roll bar, and secured from sliding by the locking pins, ensuring the fabric roll remains in fixed position relative to the vehicle centerline. The roller bar is pre-drilled at about 15-foot and about 13-foot lengths, which represent standard roll widths commonly used in road building.
A mesh assembly fabricated from about five about 16-feet to about 18-feet lengths of chain form the long (vehicle) axis of the grid, while about twelve segments of about 3.5-feet of chain create the cross axis of the grid. In stead of chain segments, a heavy cable could also be used to form the mesh grid. Similarly, a grid of solid or hollow metal bars or pipes could be arranged to drag on top of the fabric and, although not optimal for curves, the rigid grid members could serve the same function as the mesh assembly fabricated from chain segments.
A dragger bar adapts to accept the five long chains (or cable or rigid bar segments), thus dragging the dead-weight member behind the vehicle. The dragger bar is positioned to carry the chain on top of the fabric roll, weighting down the roll as it rests on the roller bar.
With receiver hitches, roller bar, hanger bar, cloth roll, and dragger bar with chains in place, the cloth is initially held down with the weight of the dragger bar chains as the conveyered material placement vehicle moves forward. The conveyered material placement vehicle then begins to place gravel on top of the cloth as it proceeds in a forward motion, driven via a remote controlled drive system. The conveyered gravel placed on top of the cloth keeps the cloth flat and firmly held on the subgrade even in windy conditions. The operator stops the truck when the roll is empty, un-clips the roller bar from the hanger bar, slides out the spent roll, places the new roll on the roller bar, lifts the dragger bar from the pair of L-hooks on the hanger bar and sets the dragger bar on the ground. Then, the new roll on the roller bar is re-clipped to the hanger bar, and the dragger bar is lifted back on the L-hooks, automatically positioning the dead-weight member on top of the new fabric roll.
A preferred embodiment of the present invention includes a device consisting of sub-components sized and weighted for one worker to remove from the vehicle when in the transport mode, assemble the components, attach the device to the receivers on the vehicle and disassemble when the job is complete.
DRAWING
FIG. 1 is a front view of a preferred embodiment of the present invention.
FIG. 2 is an off-set right-side view of the embodiment of FIG. 1 .
FIG. 3 is a partial, off-set right-side view of the embodiment of FIG. 1 .
FIG. 4 is an off-set left-side view of the embodiment of FIG. 1 .
FIG. 5 is a partial detail view of a component of a preferred embodiment of the present invention.
FIG. 6 is an off-set frontal view of one embodiment of the present invention and shows a step according to a preferred method of the present invention.
FIG. 7 is an off-set right side view of one embodiment of the present invention and shows another step according to a preferred method of the present invention.
FIG. 8 is a partial front view of one embodiment of the present invention and shows another step according to a preferred method of the present invention.
FIG. 9 is a front view of one embodiment of the present invention and shows another step according to a preferred method of the present invention.
FIG. 10 is an off-set frontal view of one embodiment of the present invention and shows another step according to a preferred method of the present invention.
FIG. 11 is a front view of one embodiment of the present invention and shows another step according to a preferred method of the present invention.
FIG. 12 is a possible environment of use of one embodiment of the present invention and depicts an aggregate delivery vehicle dispensing aggregate onto a fabric roll on a roadbed.
DESCRIPTION OF THE INVENTION
Possible preferred embodiments will now be described with reference to the drawings and those skilled in the art will understand that alternative configurations and combinations of components may be substituted without subtracting from the invention. Also, in some figures certain components are omitted to more clearly illustrate the invention.
FIGS. 1-5 illustrate a first preferred embodiment of the present invention. The present invention includes a mechanical implement 10 , specifically, for example, a device utilized to unroll and fixably locate a geotextile fabric for roadbed construction. The implement (device 10 ) adapts to couple to a rear portion of a vehicle frame (V), for example, a conveyered aggregate delivery vehicle, or more broadly a conveyered material placement vehicle, as used in roadbed construction, by cooperating with the vehicle's forward travel to unroll the fabric roll and incorporating a unique and novel dead-weight member 110 , such as a heavy yet flexible cable, rope, tubes or assembly of chain segments arranged in a mesh grid assembly to weight the recently unrolled fabric on top of the prepared sub-grade.
FIG. 1 , a front view of a preferred embodiment of the present invention, illustrates most of the major components including a support frame including a stinger member 20 , which releasable couples to the vehicle frame V and carries the principal horizontal support or hanger bar 50 . The support frame further includes a hanger bar arranged generally perpendicular to the long-axis of the vehicle frame and extending from about 6-feet to about 10 feet on each side of the vehicle's center line for a total length from about 12-feet to about 20-feet. The hanger bar includes a pair of oppositely mounted winches 60 on each extremity of the length of the bar. The winches enable workers to position and lift the relatively heavy rolls of fabric (once located on the roller bar 70 , discussed below) relative to the hanger bar and determines the height of the roll from the ground and relative to the vehicle frame. Further, opposite ends of the hanger bar each include a chain loop or hook 52 (or other attaching means) from which a first and second chain segment 72 suspends.
The chain segments 72 , in turn, support a roller bar 70 . The roller bar supports rolls of geotextile fabric as generally understood in this art. The roller bar releasably couples to the chain segments 72 at a corresponding first and second roller-bar end, each end has a corresponding end cap 74 with half-link 76 chain support means (such as a hook, receiver, quick-connect, or other coupling means) adapted to enable the chain segments 72 to attach and un-attach as needed to swap a spent roll for a new roll of fabric. Additionally, a winch cable 62 from the pair of winches 60 on the hanger bar 50 equally releasably attach to the roller bar by means of the half-links 76 .
Also suspended from the stinger assembly 20 , a dragger bar 90 arranges generally parallel to the roller bar 70 , and positions intermediately between the vehicle and the roller bar. The dragger bar includes a plurality of attaching means 92 consisting of hooks or half-links or chain, or other similar device adapted to selectively and releasably couple a link of chain to the dragger bar. A dead-weight member 110 adapts to couple (not shown in FIGS. 1-5 ) to the dragger bar at the attaching means 92 . Thus, the dead-weight member positions over the roll of fabric located on the roller bar (the roll of fabric is not shown in FIGS. 1-5 ) and extends rearward beyond the vehicle.
In the various embodiments and figures, the long horizontal members, specifically, the hanger bar 50 , the roller bar 70 and the dragger bar 90 are depicted as rigid members, solid with hollow centers having a fixed length. However, those skilled in the art will appreciate that these horizontal members may have a solid core or, alternatively, may include telescoping features to enable the bars to extend and retract to various desired lengths corresponding to transport of the device, or as needed for varying widths of the road bed, fabric roll, or application of use, for example.
For example, the hanger bar 50 , in another preferred embodiment (not illustrated in the accompanying figures) comprises a hanger member coupled to the vehicle via stinger arms 22 . The hanger member has an length of about 8-feet to about 10-feet long, or about the width of the vehicle to which it attaches. The hanger member further is adapted to receive a first and second hanger arm at opposite ends of the hanger member: Accordingly, the hanger member may be solid, with the arms inserting over the bar, or, preferably, the hanger member has a hollow core, and the arms slide inside a portion of the exposed ends of the member. The member is further configured with several though holes, arranged to correspond to similar through holes in the associated hanger arm so that a retaining pin can fixably secure the arm inside the member. In addition, the at least one hanger arm (adapted to slidebly engage a portion of the hanger member) effectively provides an adjustable and variable length hanger bar from which the roll bar suspends. It will be appreciated by those skilled in the art that this embodiment enables a geotextile roll to be positioned off-center from the vehicle, or on center with the vehicle, as needed by the application. Further, should a more narrow installation process be involved, for example, re-paving a single vehicle lane on an existing roadway or installing a geotextile roll in a roadside ditch, the present invention more readily adapts to this use.
Making general reference to FIGS. 1-11 , details of preferred embodiments of the present invention are further discussed, below. In one preferred embodiment, a geotextile-roll applicator device 10 for a vehicle frame V comprises a means for coupling the device to the vehicle frame, such as a stinger member 20 and pair of receiver hitches 30 . The receiver hitches 30 mount to the vehicle frame by any means well understood in this art including, but not limited to, welding to the frame of the vehicle. A suitable receiving hitch 30 includes a standard square receiver commonly available for tow-hitch applications as understood in this art. The stinger member 20 slideably inserts into the receiver hitch and a hitch pin 32 engages a through-hole in the stinger member and receiver hitch, while a pin chain prevents misplacing the pin when not inserted in the hole.
The stinger member 20 consists of a pair of horizontal stinger arms 22 arranged generally parallel to the long-axis of the vehicle and extending outward from the rear portion of the vehicle. Each stinger arm 22 includes a first arm-end adapted to slideably insert into the respective receiver hitch, an oppositely disposed second arm-end including a connecting means such as a U-shaped hook 24 (or other similar releasably coupling apparatus or means), and a vertically arranged holder leg 26 disposed intermediate to the first and second arm ends at holder-leg first end. The holder-leg 26 further includes a holder-leg extension member 28 adapted to slideably engage the holder-leg at a holder-leg second end and a pin cooperating with pin-receiving holes aligned on both the extension and leg locates and secures the extension relative to the leg. A connecting member, such as an L-shaped hook 29 , locates at the free end of the extension 28 . This L-shaped hook adapts to receive the dragger bar 90 , discussed below. Thus, the position of the L-shaped hook relative to the ground, vehicle, and importantly, to the roller bar 70 can be adjusted by sliding the extension member 28 in or out of the leg 26 and securing the desired position with the pin 27 .
The roller bar 70 suspends below the hanger bar 50 by a first and second suspension means consisting of two oppositely positioned and cooperating chain segments 72 . The roller bar adapts to support a roll of geotextile fabric and enables the roll to rotate on its roll-axis to dispense the fabric conventionally. The roll bar, in one preferred embodiment, includes a circular cross section, however a square cross section, oval, elliptical or rectangular cross section will work as well. A spacer plate 80 , or preferably a pair of spacer plates adapt to arrange on the roller bar and lock into position by a locking means for selectively and releasably coupling the spacer plate in a first fixed position on the roller bar. The locking means comprises a pair of spacer pins 82 that cooperate with features on the roller bar. The spacer plate enables locating the roll of fabric in a particular position relative to the center-line of the vehicle and maintains the roll in that desired position as the vehicle travels forward. Accordingly, the roll of fabric can be placed in the center, as required for a road-bed, or off center as may be required to lay fabric for a drainage ditch or retaining wall, for example. In a preferred embodiment, the roll-bar has pre-arranged pin-receiving holes at about 13-feet between cooperating holes and at about 15 feet, representing two standard widths of roll fabric. Additionally, each pin attaches to a cable coupled to its corresponding plate 80 to avoid loosing the pin when not inserted in the roller bar.
In one preferred embodiment, the hanger bar 50 carries a pair of cooperating and oppositely positioned winches 60 . However, in other preferred embodiments the winches may be omitted without detracting from the invention. Additionally, the accompanying figures illustrate a set of hand-operated winches: However, electric or hydraulic-powered winches would work equally well. Each winch includes a winch cable 62 that selectively couples to the roller bar. Then, by cranking the winch handle, the loaded roller bar can be positioned relative to the hanger bar and the chain segments 72 are attached to carry the load and the winch cable can be released and retracted for subsequent use.
A dead-weight member 110 having a generally grid-like layout comprising interconnected segments of chain loops, releasably couples to the dragger bar 90 . The dead-weight member consists of five generally parallel drag chains measuring about 15-feet to about 25-feet (preferably about 18-feet) in length and extending from the dragger bar behind the vehicle. At a spacing of about 2-feet to about 4-feet (preferably about 3.5 feet), each drag-chain includes a cross-member link chain. Thus, a grid pattern of about a 3.5-foot square grid with five columns is formed. This grid can, alternatively, be formed from cables or bar-segments in lieu of chains.
FIGS. 6-11 illustrate a first preferred method of using the device 10 of the present invention. Accordingly, this preferred method for dispensing a roll of geotextile fabric using a conveyered aggregate delivery vehicle having a frame adapted to couple to a geotextile roll applicator device, the method comprises: providing a geotextile roll; unrolling a portion of the geotextile; placing a dead-weight member provided by the applicator device over the roll and extending the dead-weight member onto the portion of unrolled geotextile; dispensing an amount of aggregate using the conveyered aggregate delivery vehicle; and advancing the vehicle forward thus causing the geotextile roll to unroll and the dead-weight member to drag on top of the newly unrolled geotextile and continuing dispensing aggregate as the vehicle advances forward.
Additionally, this method further includes steps of providing a remote control drive system for the vehicle and advancing forward the vehicle with the remote control drive system.
In another preferred embodiment, the present invention contemplates a system for dispensing geotextile fabric. The system comprises a vehicle having an aggregate dispensing mechanism that is operable to dispense aggregate from one end of the vehicle; and a geotextile-roll applicator device coupled to the vehicle adjacent the end from which aggregate is dispensed, the applicator device being configured to support a roll of geotextile fabric and dispense the fabric from the roll; wherein when the vehicle is moved along a path, the applicator device is operable to dispense fabric onto the ground along the path and the aggregate dispensing mechanism is operable to dispense aggregate from the vehicle onto the dispensed fabric.
FIG. 12 illustrates another preferred method of the present invention includes a method for dispensing geotextile fabric from a roll. The method includes the steps of supporting the roll of fabric on an applicator device, which is coupled to a vehicle; moving the vehicle along a path; and dispensing fabric from the roll onto the ground along the path as the vehicle is moved and simultaneously dispensing aggregate from the vehicle onto the dispensed fabric.
When the device 10 is not in use, for example, when it is being transported to and from a job site, the entire device dis-assembles and compactly stores on the vehicle by means of a T-rack 130 . The T-rack adapts to insert in a receiver hitch arranged vertically on the vehicle frame. The T-rack cooperates with the conveyer rack provided by the vehicle.
The various components of the preferred embodiments of the present invention are generally about 1-inch to about 2-inch square or round tube steel members welded or bolted, as conventionally understood in the art, or—as described herein—adapted to releasably couple to mating components by hooks or other fasteners as described or as would be generally understood in this art. And, although steel is contemplated, other materials would work equally well including aluminum, for example. Further, the various embodiments of the present invention and methods show a material placement vehicle (such as a conveyered aggregrate delivery truck, such as a Super Stone Slinger brand aggregate delivery vehicle available from W.K. Dahms Mfg. Ltd., of St. Jacobs, Ontario, Canada), it will be appreciated by those skilled in this art that other vehicles—including side-dump, belly-dump, or rear dump trucks—can be adapted to work with the device 10 , and may only require additional manpower or equipment to distribute aggregate on top of the unfurled geotextile.
Although the invention has been particularly shown and described with reference to certain embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention.
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An improved device for simultaneously unrolling geotextile fabric and dispensing an aggregate layer for road construction comprises a hanger bar coupled to a vehicle frame. The hanger bar supports a roller bar adapted to carry a fabric roll. A dragger couples the hanger bar and arranges to present a dead-weight member on top of the fabric. An improved method using the improved device drags the chain on top of the fabric as it unrolls, thus holding the fabric in place. At the same time, a conveyered aggregate delivery system dispenses gravel on top of the fabric.
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BACKGROUND OF THE INVENTION
This invention relates to an installation for charging a shaft furnace. More particularly, this invention relates to a charging apparatus for a shaft furnace comprising a rotating or oscillating distribution chute or spout and a hopper with a central flow duct above the spout. The flow opening of the flow duct is controlled by a metering member which symetrically regulates the flow of charge material about the central axis of the furnace. Mounted above the metering member are two containers provided with upper and lower sealing valves, as well as a metering member for regulating the flow of charge material towards the hopper.
A charging apparatus of the general type described above is disclosed in patent application LU No. 85/879 corresponding to U.S. application Ser. No. 860,653 filed May 7, 1986, assigned to the assignee hereof. According to this patent application, the metering valve of a container is initially opened so as to cause the flow of a quantity of material which is sufficient to form a barrier of material above the flow duct of the hopper. Only after this barrier has been formed is the metering valve of the flow duct above the hopper opened. In order to control the formation of this barrier, and ensure that it is present for the entire duration of a charging operation, both the hopper and the container which communicates with the latter ar weighed separately throughout the entire charging operation. As a result, signals are generated, representing in each case the contents of the hopper, the contents of the container and the combined contents of the hopper and the container.
It will be appreciated that the objective of forming a barrier of charge materials inside the hopper is to ensure that the charging material falls vertically and centrally onto the spout; and thus prevent undesired horizontal and transverse component forces caused by the charge material sliding along the slanting wall inside the hopper.
As discussed above, in the prior art apparatus, it is necessary to weigh the hopper and the container separately, thereby unduly complicating the weighing operation and the method used to process the signals supplied by the scales. Moreover, several sections with bellows joints must be provided for the flexible connections. However, it is known that such bellows joints, constitute very sensitive connections and should be avoided as much as possible.
SUMMARY OF THE INVENTION
The above-discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by the shaft furnace charging apparatus of the present invention. In accordance with the present invention, an improved charging apparatus (relative to the prior art apparatus described above) is provided which enables the weighing system to be substantially simplified and leads to a reduction in the number and dimensions of bellows joints. In the present invention, the hopper is, from a static point of view, independent of the furnace mouth. This is accomplished by locating the hopper inside a sealed chamber mounted on a frame or on the furnace mouth; and suspending the hopper using means which enable it to be coupled to the container which is being emptied and uncoupled from the container which is being filled.
In accordance with a preferred embodiment of the present invention, the means for suspending the hopper comprises a first rod which is arranged axially above the hopper, the bottom end of which is connected, via a first cross-piece, to the top part of the hopper; and a second rod, independent of the first rod, which is hollow and arranged coaxially around the first rod, the bottom end of which is connected, via a second cross-piece, to the top part of the hopper. These two rods are fixed respectively, at their top ends, to first and second hydraulic cylinders which are respectively connected to each of the two containers. The hopper preferably includes flexible, horizontal stabilization means which do not impede its freedom of movement in the vertical direction.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, wherein like elements are numbered alike in the several FIGURES:
FIG. 1 is a vertical cross-sectional view of an apparatus in accordance with the present invention;
FIG. 2 is an axial vertical cross-sectional view through the hopper of FIG. 1 rotated through 90 degrees in relation to the view shown in FIG. 1; and
FIGS. 3 and 4 are front elevation views of a system for suspending the hopper, respectively showing the parts coupling the latter to each of the two containers.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the top portion of a housing 10 containing a mechanism for driving a rotating and oscillating spout for distributing charging material in a shaft furnace. The spout (not shown) is well known and is located inside the top of the shaft furnace. Two storage containers 14 and 16 are arranged next to each other on either side of the vertical axis 0 of the furnace. Containers 14 and 16 rest on scales 18 mounted on base or platform structure 20 which is supported by a frame 22. Frame 22 is positioned on the wall of the furnace. In order that containers 14 and 16 may be independently weighed, neither container has any parts connecting them to base 20, apart from flexible plates 24 and 26 which ensure their horizontal stability, but which do not affect their vertical freedom of movement in relation to scales 18 and platform 20.
Containers 14 and 16 are provided, in a manner known per se, with upper sealing valves 28 and 30, lower check valves 32 and 34, as well as lower sealing valves. It will be appreciated that only the sealing valve 36 associated with container 14 is shown in FIG. 1.
Between the two containers 14 and 16 is a sealed chamber 40 which can be connected to each of containers 14 and 16 by opening the lower sealing valve 36. Sealed chamber 40 is connected to the inside of the furnace through housing 10 by means of the only bellows joint required in the installation (bellows joint 42), which is necessary for operation of a sliding gate 44 provided immediately above housing 10. Sealed chamber 40 has an interior hopper 46 preferably in the form of a funnel provided with a lower flow duct 48 (see also FIG. 2).
Turning now to FIG. 2, in accordance with an important feature of the present invention, hopper 46 is freely suspended, by means of a first cross-piece 50, from a first axial rod 52 extending along the central axis 0; and by means of a second cross-piece 54, from a second axial rod 56 which is hollow and which is arranged coaxially around first rod 52, while being completely independent of the latter. Rods 52 and 56 extend from sealed chamber 40 through a sealing bellows 58 which surrounds, in sealed fashion, external rod 56 without impeding its freedom of vertical movement. Inside chamber 40, each of rods 52 and 56 is connected to the walls of the chamber by flexible plates 60 and 62 (see FIG. 1) which ensure the horizontal stability of hopper 46 without impeding its vertical freedom of movement. Hopper 46 is additionally stabilized by a flexible plate 64 connecting it to the wall of chamber 40.
A metering valve 68 and its associated actuating or drive mechanism 70 are also mounted on hopper 46 by means of vertical skirts 72 and 74 integral with the latter. The drive shafts connecting drive mechanism 70 to valve 68 pass through the lower wall of chamber 40 with the aid of a flexible sealing device 76 which allows metering valve 68 and its drive mechanism 70 to retain their freedom of vertical movement.
A more detailed description now follows, with reference to FIGS. 3 and 4, of the means and method for suspension of hopper 46 and the way in which it is coupled to either container 14 or container 16. The top end of hollow rod 56 is integral with a bracket 80, the top of which supports two parallel lugs 82 and 84 through which there passes a trunnion 86 which is freely moveable about its horizontal axis inside lugs 82 and 84.
Trunnion 86 is connected by an eyelet 94 to a hydraulic cylinder 88. The rod 92 of the piston 90 of cylinder 88 is coupled to container 16 by means of a horizontal bar 96 integral with container 16. The top end of rod 52 is connected, in turn, to container 14 in the same manner as bracket 80 is connected to container 16. Accordingly, in illustrating the method of connection of rod 52 to container 14, the same references, with primes, have been used as those used for the corresponding parts coupling bracket 80 to container 16.
Since rod 52 is freely movable in relation to hollow rod 56, the annular space between these rods allowing this freedom of movement is subject to the pressure prevailing inside hopper 46. Consequently, it is necessary to provide a flexible sealing joint between the end 100 of internal rod 52 and the bottom of bracket 80 which is integral with external rod 56.
Operation of alternative methods of coupling hopper 56 to container 14 and to the container 16 will now be described with reference to FIGS. 3 and 4. In the case of FIG. 3, the annular space around rod 92' of piston 90' is filled with hydraulic fluid under pressure which thus supports cylinder 88' as well as rod 52. I other words, hopper 46 as well as its metering valve 68 and drive mechanism 70 driving the latter are coupled to container 14 in such a way that the weight of container 14, determined via scales 18, provides an indication of the contents of container 14 and of the contents of hopper 46.
Conversely, cylinder 88 is not under pressure, i.e., it is freely movable in relation to its piston 90 and the weight of hopper 46 has no effect on container 16. The latter, as shown in FIG. 1, is being filled, so that scales 18 provide signals which indicate the extent to which it is filled.
When container 16 has been filled and container 14 has been emptied via hopper 46, their functions must be reversed by operating the various valves so as to allow container 14 to be filled and container 16 to be emptied. It is at this point that hopper 46 is uncoupled from container 14 and coupled to container 16. For this purpose, the annular space around rod 92 of piston 90 is pressurized in order to support cylinder 88. Cylinder 88 therefore supports, via bracket 80, both rod 56 and hopper 46 which is now coupled to container 16. At the same time, the pressure inside cylinder 88' is released, thereby resulting in cylinder 88' and hopper 46 being uncoupled from container 14.
Instead of coupling piston rods 92 and 92' to containers 16 and 14 so that rods 56 and 52 are supported by cylinders 88 and 88' respectively, it will be appreciated that cylinders 88 and 88' may be coupled to containers 16 and 14 so that the rods 56 and 52 are supported by their piston rods 92 and 92' respectively.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it to be understood that the present invention has been described by way of illustrations and not limitation.
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The apparatus comprises a distribution spout and a hopper which has two containers mounted thereabove provided with sealing valves and a metering member. In order to simplify the weighing system, the hopper is independent of the mouth of the furnace and is located inside a sealed chamber. The hopper is suspended by a device which enables it to be coupled to the container which is being emptied and to be uncoupled from the container which is being filled.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the improvement of the resistance to wear and cavitation exhibited by plastics overlays on composite materials used as bearings for oil-lubricated applications. In particular, the invention provides an increase in the service life of shock absorbers and composite bearings used under shock absorber-type conditions.
2. Description of Related Art
Materials used for composite bearings with plastics overlays consist of a metallic backing layer, preferably of steel, bronze or a high-strength aluminum alloy, and a sealed plastics overlay applied directly to the metal backing. As an alternative to this, the plastics overlay may also be applied to a porous intermediate layer of sintered metal, in such a way that the pores are also completely filled with plastics material. The plastics overlay comprises PTFE as its base material and additionally contains wear- and friction-reducing additives.
For bearing systems such as these where oil is present, a very low coefficient of friction accompanied at the same time by a high degree of resistance to wear and cavitation is very important, for example in shock absorbers which are used in the automobile industry or in gear pumps or hydraulic motors. Owing to the low coefficients of friction necessary, current knowledge insists that such materials consist to a considerable extent of PTFE, since no other known plastics satisfy these requirements, even when their other properties are suitable.
Since PTFE alone is too soft, and therefore has a high coefficient of wear, materials must be mixed with it which counter cavitation and wear without substantially increasing the coefficient of friction.
The bearing materials used most commonly at present in the above-mentioned area of application consist of a steel backing, a porous bronze layer and a plastics material of which approximately 80 vol. % is PTFE and the rest is lead or molybdenum disulphide. The plastics material is pressed into the bronze framework and forms a thin sealed layer thereover. However, materials with this structure have a tendency to produce erosion and cavitation phenomena under extreme conditions, such as arise in shock absorbers for example through heavy loads, high sliding speeds and acceleration rates and high flow speeds in the bearing gap, and therefore have only a limited service life, especially when highly stressed.
Although it is possible to produce materials which exhibit hardly any wear and no susceptibility to cavitation under the above-described conditions if a thermoplastic material other than PTFE is used, for instance PVDF or PEEK, a marked increase in friction in the case of oil lubrication has in such cases to be accepted.
Many documents propose PTFE-based compositions which, however, have hitherto provided relatively only slight improvements over the above-mentioned standard materials and generally have an increased coefficient of friction, as in the case of calcium fluoride, put forward in EP 183375 A2, or of polyimides, as proposed in DE 4227909 C2.
WO 95/02772 proposes the use of an aramide fibre pulp to reduce wear and cavitation, but the homogeneous mixing-in of these fibres causes problems and requires appropriate additional production equipment.
In contrast thereto, it is the object of this invention to make it possible, without altering production processes and without impairment of the coefficient of friction when oil is used, to achieve service lives which surpass several times those of the corresponding materials according to the prior art.
SUMMARY OF THE INVENTION
In particular, the use of iron oxide as a wear- and cavitation-inhibiting additive in plastics overlays, consisting predominantly of thermoplastic fluoropolymers, of composite bearings for oil-lubricated applications makes it possible markedly to increase the service lives of these composite bearings for oil-lubricated applications without any disadvantageous effect on the extraordinarily low coefficient of friction of the plastics overlays when oil is used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It is sufficient, in the context of the invention, to add a small amount of iron oxide to the otherwise conventional standard compositions of plastics overlays for composite materials.
Although mention is frequently made of the possibility of using iron oxide as a filler in self-lubricating PTFE-based bearing materials, as in DE 4105657 C2 for example, it is used only as a "neutral element" and may be replaced by other oxides or oxide combinations, rather than being absolutely essential for the achievement of a specific property. Furthermore, in the above patent the presence of a meltable fluorothermoplastics material is given as an additional prerequisite.
In JP 04114094 A2, the addition to PTFE of iron oxide together with glass fibres is recommended for sliding elements in contact with foodstuffs. This is not relevant to the above-described instances of use, since hard material particles such even as glass have an undesirably abrasive effect and over time impair the function of the components in such cases while resulting additionally in a high coefficient of friction.
It has surprisingly been found that, when iron oxide is added to PTFE-based materials, fatigue cracking of the sliding surface owing to cavitation phenomena is greatly decreased. On the other hand, when used in the absence of lubricants, the materials with added iron oxide come off less well than the corresponding iron oxide-free compositions. A link between the durability of plain bearing materials under the above-mentioned conditions and the addition of iron oxide had never previously been established.
In an advantageous embodiment of the invention, use is made of the following in the production of plastics overlays for oil-lubricated composite bearings:
(i) 0.5-10 vol. % iron oxide in a plastics overlay which additionally comprises
(ii) 55-90 vol. % of one or more thermoplastic fluoroplastics and
(iii) 9.5-44.5 vol. % of lead, lead oxide, metal sulphides with a lamellar structure, metal fluorides, boron nitride, graphite, carbon black or coke, separately or in combination, wherein (i), (ii) and (iii) are so selected that together they add up to 100 vol. %, wherein the plastics overlay
(iv) may contain conventional additives which make up the residual amount if (i)+(ii)+(iii) adds up to less than 100 vol. %.
Consequently, a plastics material for use in the context of the invention as a plastics overlay is basically composed of 55 to 90 vol. % PTFE, with which are mixed, separately or in combination, 9.5-44.5 vol. % of the known fillers lead, lead oxide, metal sulphides with a lamellar structure such as molybdenum sulphide, metal fluorides, boron nitride or graphite, carbon black, coke, wherein the plastics composition further contains 0.5-10 vol. % iron oxide.
The preferred form of iron oxide used is Fe 2 O 3 . The plastics material of the overlay advantageously consists predominantly of PTFE.
Parts of the PTFE may also be replaced by parts of other fluorothermoplastics. Fluorothermoplastics which may be used within the context of the invention comprise, inter alia, homopolymers such as PCTFE (polychlorotrifluoroethylene), PVDF (polyvinylidene fluoride), PVF (polyvinyl fluoride), alternating copolymers such as ETFE (polyethylene-tetrafluoroethylene alternating copolymer), CM-1 (polyvinylidene-hexafluoropropylene alternating copolymer) and/or random copolymers such as FEP (polytetrafluoroethylene-hexafluoropropylene copolymer) and PFA (copolymer of tetrafluoroethylene and perfluorovinylalkylether). The use of other additives such as fibres, plastics, hard materials, dyes etc is also possible within the context of the above-mentioned proportions.
In a particularly advantageous modification, a material is used as the overlay which is obtained if
(i) 1-6 vol. % Fe 2 O 3 ,
(ii) 65-75 vol. % PTFE and
(iii) 24-34 vol. % lead, lead oxide, molybdenum disulphide, metal fluorides, boron nitride, graphite, carbon black or coke, separately or in combination, are used, wherein (i)+(ii)+(iii) amount to up to 100 vol. % and, if (i)+(ii)+(iii) add up to less than 100 vol. %,
(iv) fibres, plastics, hard materials and/or dyes are optionally additionally contained in the plastics overlay to make up the residual amount.
This results in an overlay with particularly advantageous properties.
Fe 2 O 3 is best used in its red and/or brown α-form.
It is also preferable, within the context of the invention, to use Fe 2 O 3 in the form of spherical primary grains with an average particle size of ≦5 μm.
The use of Fe 2 O 3 with particle sizes ≦5 μm is particularly advantageous.
Particularly good results are achieved with Fe 2 O 3 using filler combinations consisting of metal sulphides with a lamellar structure and hexagonal boron nitride.
By way of example, three possible embodiments are compared with the corresponding materials without added Fe 2 O 3 . The compositions are given in Table 1.
TABLE 1______________________________________Example No. Composition in Vol. %______________________________________1 PTFE 70 MoS.sub.2 27 Fe.sub.2 O.sub.3 32 PTFE 70 MoS.sub.2 303 PTFE 70 Graphite 27 Fe.sub.2 O.sub.3 34 PTFE 70 Graphite 305 PTFE 70 BN 13.5 MoS.sub.2 13.5 Fe.sub.2 O.sub.3 36 PTFE 70 BN 15 MoS.sub.2 15______________________________________
The production of samples may be carried out in a known way:
homogeneous suspension of the fillers and the iron oxide in water by means of a non-ionic wetting agent;
addition of a 30% PTFE dispersion and homogeneous mixing;
achievement of coagulation of the mixture by means of aluminium nitrate solution;
removal of excess water and stirring until the composition is of a coating consistency;
rolling of the mixture into the porous bronze framework applied to steel;
sintering of the PTFE at 380° C.;
hot compression of the overall structure by rolling.
Bushings of these materials were subjected to a shock absorber test, during which the service life under particularly cavitation- and wear-promoting conditions was determined. The test was carried out on bushings with a running surface width of 10 mm in twin-tube dampers with a rod diameter of 22 mm under a constant lateral load of 2000 N. Ramp-shaped and sinusoidal movements each of 0.5 Hz and with a peak-to-peak amplitude of 80 mm were effected alternately for periods of 20 seconds, until the destruction of the overlay owing to leakage of the damper became apparent. The tests were broken off after a maximum of 120 hours, however.
Furthermore, the coefficients of friction of the materials in the bushing/rod system under drip-feed lubrication were measured under a specific load of 3 MPa and at a sliding speed of 0.01 m/s.
The data are assembled in Tab. 2.
TABLE 2______________________________________ Service life in Coefficient ofExample No. cavitation test [h] friction, oiled______________________________________1 85 0.0222 37 0.0203 17 0.0384 5 0.0345 >120 (test broken 0.016 off)6 33 0 017______________________________________
These results show just how great is the positive influence of the iron oxide on the wear- and cavitation-resistance and that the coefficient of friction is barely influenced thereby.
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Iron oxide functions as a wear- and cavitation-inhibiting additive in the plastic sliding layer(s) of composite bearings for oil-lubricated applications. The sliding layers predominantly consist of thermoplastic fluoropolymers. The addition of iron oxide to PTFE-based materials reduces the destruction of the sliding surface owing to the appearance of cavitation if the materials are used in the presence of oil.
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This is a divisional of U.S. application Ser. No. 08/492,343 filed Jun. 19, 1995, now U.S. Pat. No. 5,837,808 issued Nov. 17, 1998, which is a continuation of U.S. application Ser. No. 08/116,939 filed Sep. 7, 1993, now abandoned, which is a continuation-in-part of U.S. application Ser. No. 07/747,565 filed Aug. 20, 1991, now abandoned. Both U.S. application Ser. Nos. 08/492,343 and 07/747,565 are incorporated herein by reference and are made a part hereof.
TECHNICAL FIELD
This invention relates to analogs of hirudin and in particular relates to analogs of hirudin which have antithrombogenic activity and which can be bound to polymers.
BACKGROUND ART
Natural hirudin is a mixture of closely related polypeptides each containing approximately 64 to 66 amino acids and having a molecular weight of approximately 6900 daltons. At least 20 natural variants of hirudin have been identified. Scharf et al., FEBS Letters 255 pp. 105 to 110 (September 1989). It is produced by the European medicinal leech Hirudo medicinalis. It prevents blood from clotting by forming an inhibitory 1:1 molecular complex with activated thrombin (approximately K iApp =10 -11 to 10 -14 M). Hirudin forms a very tight complex with thrombin, wherein over 40% of the hirudin structure intimately contacts the thrombin molecule and covers both the fibrinogen recognition site of thrombin and the fibrinogen cleaving (active) site of thrombin. Twenty-seven of the sixty-five residues of hirudin have contacts less than 4.0 Å with thrombin. This close fit prevents both the binding and cleavage of fibrinogen by thrombin.
It is impractical to prepare natural hirudin in quantities necessary for therapeutic use. At least three recombinant hirudins are now available identical to native variants, except the recombinants lack the sulphate residue on the tyrosine at position 63 found in native variants. These recombinant hirudins show pharmacological properties very similar to native hirudin (Markwardt, Sem. Thromb. Hemostas. 15 pp. 269 to 282 (1989)). European Patent Application 87402696.6 shows the amino acid sequence of hirudin variants 1, 2, and 3 (HV1, HV2 & HV3).
Three regions of the hirudin molecule are now believed to be essential to the thrombin-hirudin high affinity interaction based on X-ray crystallography (Rydel, et al., Science 249 (1990) pp. 277. to 280) and structure-activity studies (Krstenansky, et al., J. Med. Chem. 30 (1987) pp. 1688 to 1691). First, the three NH 2 -terminal amino acid residues at positions 1, 2, and 3 of hirudin form a parallel beta strand with Ser 214 to Glu 217 of thrombin and participate in several dozen non-polar interactions with side chains of amino acids in and around the active site of thrombin. Second, the NH 2 -terminal domain of hirudin from approximately Thr 4 to Pro 48 is a compactly folded structure composed of four loops stabilized by three disulfide bridges and antiparallel beta structures. The main function of this domain is to position and facilitate the interaction of hirudin's NH 2 -terminal tripeptide at the thrombin active site. Third, the COOH-terminal tail of hirudin (Glu 49 -Pro 60 ) binds in the anion-binding exosite of thrombin and terminates in a hydrophobic helical turn defined by the sequence Glu 61 -Leu 64 . The exosite constitutes the fibrinogen binding recognition site of thrombin and is dominated by numerous polar and non-polar interactions. The presence of hirudin in the exosite prevents fibrinogen from being recognized.
Most research on the hirudin molecule has focussed on (i) determining the roles of various regions of the molecule in its interaction with thrombin, and (ii) making modifications to the molecule to increase the binding affinity between hirudin and thrombin and thereby reduce the necessary dose in therapeutic applications. Some research has focussed on prolonging the activity or half-life of hirudin in vivo, and other research has been in the area of immobilizing hirudin on surfaces used in medical devices which come in contact with blood to provide a non-thrombogenic surface.
a. Modifications to Increase Binding Affinity or to Prolong In Vivo Half-Life of Hirudin
PCT Application WO 85/04418 discloses recombinant HV2 where Lys 24 , Asn 33 , Lys 35 , Gly 36 , Asn 47 , Glu 49 , and Asn 53 are replaced by Gln, Asp, Glu, Lys, Lys, Gln, and Asp respectively.
European Patent Application No. 87402696.6 discloses recombinant variants 1, 2, and 3 where Tyr 63 or 64 is replaced by Glu or Asp and Lys 47 or Asn 47 is replaced by Arg or His.
European Patent Application No. 89400621.2 also discloses amino acid sequence modifications, including those at positions 1, 2, 33, 35, 36, 47, and 63, which increase the in vivo half life of the molecule, increase the specificity of the molecule's interaction with cell surface receptors and increase resistance to carboxypeptidase degradation. Arg is placed in the 33 position, Thr or Ser or Asp are placed at position 35, and Ser is placed at position 36.
European Patent Application No. 89810521.8 describes mutations at the 53, 57, 58, 61, 62, and 63 positions which, depending upon the analog selected, provide increased or decreased antitnroubogenic activity.
U.S. Pat. No. 4,179,337 discloses the attachment of mass-increasing molecules such as polyethylene glycol to proteins.
Lazar, et al. describe mutations at position 3 in recombinant hirudin variant 1 (rHV1) where antithrombin activity was increased by replacing Tyr with Phe or Trp, and markedly decreased by replacement with Thr (J. B. Lazar, R. C. Winant & P. H. Johnson. J. Biol. Chem. 266 pp. 685-688 (1991)).
Johnson, P. H. 1 et al. in "Biochemistry and Genetic Engineering of Hirudin", Seminars in Throbosis and Hemostasis, Vol. 15 No. 13 (1989) at pp. 309 describes hirudin fragments having antithrombogenic activity. These fragments correspond to residues 42 to 65 and 51 to 65.
European Patent Application No. 89810522.6 describes mutations at positions 1, 27, 36, 47, 48, 49, 51 and 52. The substitution at 36 is Lys, Arg, Asn, Val, Leu or Gln. The substitution 27 is Gln, Asn, Leu, Arg, or Val. The substitution at 49 is Asn or Met. The substitution at 47 is Arg, Asn, Val, or Leu.
European Patent Application No. 89810676.0 describes mutations at positions 1, 2, 27, 36, 47, 57, 58, 61, and 66 where the position 27 substitution is Gln, position 36 substitution is Gln and position 47 substitution is Arg.
The following references disclose modifications at the C-terminal and N-terminal ends of the hirudin molecule: European Patent No. 142860; U.S. Pat. No. 4,801,576; U.S. Pat. No. 4,745,177; U.S. Pat. No. 4,767,742, and European Application No. 86102462.8.
U.S. Pat. No. 4,791,100 discloses mutations of hirudin in positions corresponding to, inter alia, 35 and 36, where at 35 the substitution is Glu and at 36 the substitution is Lys. It also discloses analogs having a greater number of amino acids than native hirudin and others having fewer amino acids than native hirudin.
b. Immobilization of Hirudin on Surfaces
European Application No. 89311022.1, European Application No. 89307922.8 to Ito, and references cited therein disclose the attachment of hirudin to surfaces. The data disclosed in the Ito application shows substantial loss of antithrombogenic activity occurred when the molecule was immobilized on the surface.
c. Fragments
Various COOH-terminal polypeptide fragments of hirudin are known to bind to thrombin, thereby inhibiting the binding and cleavage of fibrinogen by thrombin. The minimum length polypeptide required to exert inhibitory activity has been reported as Phe 56 -Gln 65 (J. L. Yrstenansky, T. J. Owen, M. T.
Yates & S. J. T. Mao. J. Mec Chem 30 pp. 1688-1691 (1987)). Addition of amino acid residues to this polypeptide to increase its length and provide the amino acid sequences found in the several hirudin variants up to and including the complete sequences Glu 49 -Gln 65 augments the thrombin inhibitory activity of the fragments; and, the sequence may be extended to include Gly 42 -Gln 65 without compromising the efficacy of the inhibitor. Moreover, the deletion of Gln 65 from the polypeptides of these series provides an analogous series of useful thrombin inhibitory peptides.
In a further extension of this reasoning, numerous synthetic variations of the polypeptide sequences found in the natural hirudin variants (peptidomimetic analogs of hirudin peptides) have been prepared and found to possess thrombin inhibitory activity. Notable among them are those described in European Patent Application No. 89302159.2 and others utilizing non-protein amino acids (European Patent Application No. 89122451.1).
Maraganore, J. M. at al. in an abstract presented at a symposium entitled "Biomedical Horizons of the Leech" on Oct. 24-28, 1990 disclose synthetic peptides which bind to both the anion binding exosite and the active site. The peptides are called "hirulogs" and consist of (i) an active-site specificity sequence, (ii) a poly-Gly linker, and (iii) an anion binding exosite recognition sequence.
There are many variations possible on this model of bivalent thrombin inhibitors and in general, bivalent protease inhibitors. For example see J. M. Maraganore, P. Bourdon, J. Jablonski, K. L. Ramachandran and J. W. Penton,II. Biochemistry 29 pp. 7095-7101 (1990); J. DiMaio, B. Gibbs, D. Munn, J. Lefebvre, F. Ni, and Y. Konishi. J. Biol. Chem. 265 pp. 21698-21703 (1990).
European Application No. 89302160.0 discloses peptides of about 8 to 26 amino acids having the biological activity of hirudin.
European Application No. 89302159.2 discloses cyclicized synthetic fragments of hirudin having antithrombogenic activity.
It is a primary object of this invention to provide antithrombogenic hirudin analogs having amino acids available for attachment of spacer molecules. The analogs can be bound to a surface via a spacer molecule rendering the surface nonthroenic. Alternatively, the analogs can be bound to a polymer via a spacer molecule to increase the analogs' in vivo half life. It is a further object of this invention to provide nonthroibogenic materials comprising such analogs attached to surfaces. It is a further object of this invention to provide analogs attached to polymers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the amino acid sequence of HV2-Phe 3 Gln 33 Tyr 35 Lys 47 Asp 63 and its encoding DNA sequence.
FIG. 2 depicts the expression vector for the sequence in FIG. 1.
SUMMARY OF THE INVENTION
The present invention provides an analog of hirudin having at least one amino acid in positions 30 to 37 substituted with Tyr, and the native Tyr 3 and Tyr 63or64 residues substituted with a first and a second functional nonreactive amino acid.
A preferred embodiment of the invention is an analog of hirudin having at least one amino acid in positions 32 to 36 substituted with Tyr, the native Tyr 3 substituted with Phe, Ile or Leu, and Tyr 63or64 substituted with Asp or Glu.
As used herein the term analog includes fragments and analogs of hirudin wherein a tyrosine residue is attached to the NH 2 -terminal position of such analogs, and the residue equivalent to Tyr 63 , when present, is substituted with either Glu or Asp.
As used herein the term analog includes peptidomimetic analogs of hirudin which are bivalent inhibitors of thrombin, where a tyrosine residue is inserted in or near the oligomer that links the COOH-terminal hirudin poptide mimic to the peptide that binds in the active site of thrombin, and where a functional nonreactive amino acid, preferably Asp or Glu, replaces the residue equivalent to Tyr 63 .
The present invention also overcomes the disadvantages of the prior art by providing an antithrombogenic hirudin analog covalently attached to a spacer molecule at a reactive nonfunctional Tyr residue of the analog.
The present invention further provides Applicant's novel analogs attached to surfaces rendering such surfaces nonthrombogenic.
The present invention further provides Applicant's novel analogs attached to mass-increasing molecules, which will have a prolonged half-life in vivo.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides analogs of hirudin having at least one "reactive" amino acid in positions 30 to 37 and having a "functional" but "nonreactive" amino acid at positions 3 and 63. A prominent loop or finger region extends out away from the hirudin-thrombin interface and contains at its tip the sequence Leu 30 Gly 31 Ser 32 Asn 33 Gly 34 Lys 35 Gly 36 Asn 37 (SEQ ID NO:1) (for hirudin variant 2). Amino acid substitutions in this region are believed not to affect the interaction of hirudin with thrombin. See European Patent Application No. 89400621.2 and Rydel, et al., Science 249 pp. 277 to 280 (1991). In accordance with the present invention this loop is a preferred site for substitution with Tyr to allow the attachment of a spacer molecule for surface immobilization of a hirudin analog to render the surface nonthrombogenic. Alternately, in accordance with the present invention, the novel hirudin analog may be bound to an oligomer, a polymer, a macromolecule, or other mass-increasing molecule, thereby increasing the effective molecular weight of hirudin and prolonging its in vivo half-life and its anticoagulative effect in the circulation when administered therapeutically.
To avoid reaction of the spacer molecules or mass-increasing molecule with Tyr in positions outside the finger region, where attachment to a molecule might destroy antithrcsnogenic activity, Tyr residues outside the finger region are substituted with amino acids that will not react with the spacer. As used herein, the term "nonreactive" shall mean an amino acid which, due to its nature and/or position within the analog, will not form a covalent bond with certain mass-increasing and spacer molecules described below. As used herein the term "functional" shall mean an amino acid in a particular position necessary for the analog to have antithrombogenic activity.
Hirudin includes a Tyr at positions 3 and 63 or 64, which are functional in the sense that they are believed to be necessary for the molecule to have antithrombogenic activity (See European Patent Application No. 87402696.6 and Lazar et al., op. cit.). However, the native Tyr at 3 and 63 are also reactive. If not substituted these amino acids will react with the spacer or mass-increasing molecule rendering the product ineffective as an antithrombogenic agent. European Patent Application Nos. 87402696.6 and 89810521.8 suggest that the substitution of Asp or Glu for the native Tyr at position 63 will not destroy the antithrombogenic activity of the analog. X-ray crystallographic studies showed that in a hirudin-thrombin complex, Tyr 3 of hirudin occupies a hydrophobic cleft adjacent to the active site of thrombin that is occupied in a similar manner by the Phe residue of the thrombin inhibitor, PPACK (Phe-Pro-Arg-chloromethylketone) (Rydel, et al., op. cit.) This suggests that substitution of Phe for Tyr 3 would not significantly reduce the antithrombogenic activity of the analog.
Accordingly, in the analog of the present invention, the functional Tyr 3 , and Tyr 63 are replaced with functional yet nonreactive amino acids to prevent reaction of the spacer or mass-increasing molecule at the functional positions. The preferred functional, nonreactive amino acids for position 3 in hirudin are Phe, Leu and Ile. The preferred functional, nonreactive amino acids for position 63 or 64 are Asp and Glu. When both the finger region substitution and these terminal substitutions are made the result is an analog having Tyr available for reaction with a spacer or mass-increasing molecule in the nonfunctional finger region and functional, yet nonreactive amino acids in positions 3 and 63 or 64.
In a preferred embodiment Tyr is placed at position 35 in hirudin. Tyr may also preferably be placed at position 33.
As disclosed in European Application No. 87402696.6, in hirudin variant 2 native Asn at 47 may be substituted with Lys to enhance the binding affinity of the molecule to thrombin.
The present invention requires at least one nonfunctional amino acid available for reaction. The inclusion of additional nonfunctional reactive Tyr substitutions may enhance the usefulness of the analog for chemical attachment to surfaces or in promoting increased in vivo half life of the analog. Those skilled in the art using routine experimentation will be able to determine whether the introduction of too many of the disclosed Tyr substitutions in the analog will impair its usefulness in chemical attachment to surfaces or to mass-increasing macromolecules, due to, for example, steric hindrance of the portions of the analog which bind to thrombin.
The analogs of the present invention may be prepared using recombinant DNA techniques known to those skilled in the art, for example, by subjecting the gene that codes for hirudin to site-specific mutagenesis and expressing the mutated gene in a suitable host such as a yeast or bacterium. European Patent No. 200655 discloses an expression system for hirudin in yeast. The plasmid used to transform the yeast may be altered by methods known to those skilled in the art to create the novel mutations described herein. European Patent Application Nos. 89810521.8 and 89810522.6 of Ciba Geigy AG and patent applications cited therein disclose microbial hosts for vectors containing hirudin DNA sequences. The analog described in Example 1 below was made by the methods disclosed in European Patent Application Nos. 87401649.6 and 8940062,1.2.
Those skilled in the art will understand that fragments of the hirudin molecule, COOH-terminal polypeptide fragments, peptidomimetic analogs, and bivalent inhibitors (as described above in the section entitled "Fragments") may also be modified according to the criteria of the present invention provided that such "fragment" has at least one site where a Tyr may be substituted without eliminating the antithrombin activity of the "fragment", and further provided that the functional groups on the "fragment" are either nonreactive or can be substituted with a functional nonreactive amino acid. Fragments or peptides having such activity and modifications thereof fall within the intent and scope of the present invention. Accordingly, the term analog as used herein shall include a fragment of the hirudin molecule, peptidomimetic analogs, and bivalent inhibitors having antithrombogenic activity. The term analog as used herein shall include a synthetic peptide having antithrombogenic activity by virtue of an amino acid sequence analogous to that of the functional portions of the-native hirudin molecule.
For example, the NH 2 -terminal end of the hirudin peptides and peptidomimetic analogs known to inhibit thrombin activity has a lesser influence on their effectiveness than the COOH-terminal residues. See Johnson, P. H. et al. in "Biochemistry and Genetic Engineering of Hirudin", Seminars in Thrombosis and Hemostasis, Volume 15, No 13 (1989) and J. L. Krstenansky, T. J. Owen, M. T. Yates, and S. J. T. Mao, J. Med. Chem. 30, PP. 1688-1691 (1987). Attachment of a Tyr residue to the NH 2 -terminal end or equivalent region of these various inhibitory polypeptides, and peptidomimetic analogs, accompanied by substitution of the Tyr equivalent residue by Asp or Glu, provides a unique attachment site for an immobilizing spacer molecule or mass-increasing molecule according to the methods of this invention.
The bivalent thrombin inhibitors described by .Maraganore et al., Biochem. 29, pp. 7095 to 7101 (1990) offer design flexibility in the placement of a reactive amino acid residue for attachment of spacer or mass increasing molecules. A tyrosine residue inserted in or near the oligoglycine connecting link that joins the active site binding moiety with the longer peptide that binds in the fibrinogen recognition site provides a unique site for attaching a spacer, when in accordance with this invention, the Tyr 63 Univalent residue is replaced with Glu or Asp.
Tyr is used for spacer attachment because it provides for site specific chemical reactions that avoid binding the spacer to other residues that could interfere with hirudin's activity. The specificity of these reactions depends on the altered reactivity of groups inserted into the phenolic ring of Tyr. A preferred means to attach a spacer to a Tyr residue is to insert a primary amine into its phenolic ring. Many reagents developed for derivatization and immobilization of proteins are designed to react with primary amino groups in their neutral, unprotonated state. Use of these reagents with hirudin under usual derivatization conditions will impair the antithrombin activity of hirudin by attaching spacer molecules to its NH 2 -terminal amine or to certain of its lysyl epsilon-amino groups. An aryl amine on Tyr avoids these drawbacks by reacting with amine reactive agents under conditions that virtually exclude reactivity with the alkyl amines of Lys and the NH 2 -terminal amino acid residue. An aryl amine of Tyr has a pK a of about 4.8, i.e., it is 50% protonated at pH 4.8. Since the protonated form of a primary amine is unreactive to the commonly used spacer attachment chemistries, the tyrosyl amine residue will react at about 50% efficiency at pH 5.0. However, at pH 5.0, less than 0.1% of the alpha-amine of the NH 2 -terminal residue (pK a about 8.0), and less than 0.001% of the epsilon-amine of Lys (pK 8 about 10.0) will be reactive with such spacer chemistries. This provides the site-specificity. However, chemical methods that insert an amine into the phenolic ring of Tyr may also react with Trp and free Cys; however, hirudin has no Trp residues and all 6 Cys residues are engaged in unreactive disulfide bridges. Therefore, specific reactivity with Tyr is obtained.
A less preferred means to attach spacers to Tyr uses spacers activated with diazonium salts, which react directly and efficiently with the phenolic ring of Tyr. However, this reaction is not specific to Tyr, since His residues also react and hirudin's only His is essential to thrombin binding. Other less preferred spacer chemistries used to attach spacers to Tyr residues are photo-oxidation, N-bromosuccinimide and sulfonyl halides which also react with amino acid side chains other than Tyr.
Spacers capable of reacting predominantly with aryl amines rather than with alkyl amines at about pH 5.0 include, but are not limited to, those containing N-hydroxysuccinimidyl esters, imidate esters, thiolactones, carboxyanhydrides, sulfonyl halides, isourea esters, benzoquinones, vinyl sulfones, hydrazides and imidazolyl carbonyls. Typically such spacer molecules are bifunctional, wherein one end of the spacer contains an amine-reactive chemical moiety, while the other end contains the same or a different reactive species for attachment to the surface.
Whereas the spacer molecule is covalently bound to hirudin or its analogs in accordance with the present invention, the attachment of the spacer to the surface may occur by any binding means or combination of binding means, that will retain a sufficient concentration of hirudin or its analogs at the surface to provide a nonthrombogenic and anticoagulant surface under the conditions of use.
Attachment of the hirudin analog and its spacer to the surface may be by covalent means, reacting the group on the free end of the spacer with a reactive group on the surface. Alternately the hirudin-spacer conjugate may be coupled to a reactive group on the free end of a different spacer or on a macromolecule which are themselves covalently bound to the surface. The preferred chemical reactions to attach hirudin analogs to a surface or to a surface-bound spacer are those that occur rapidly and quantitatively under moderate conditions and avoid reaction with reactive amino acid side chains of hirudin and its analogs or denaturation of the molecule. Examples of such reactive pairs include, but are not limited to, thiol-maleimide, thiol-iodoacetate, and hydrazide-aldehyde (from oxidized sugar cis-diols). Alternately, the hirudin analog and its spacer may be attached to the surface by non-covalent binding means, which may include, for example, those that operate predominantly by hydrophobic binding mechanisms, or by fluorophilic associations, or by high affinity ligand receptor binding. The spacer attached to the hirudin analog may have at its free end, for example, a hydrophobic or a fluorophilic moiety that will bind directly to a similarly hydrophobic or fluorophilic surface. Or, the said spacer may have at its free end a chemical moiety that reacts to produce a covalent bond with the free end of a second spacer that is attached to the surface by non-covalent means. In another embodiment, the hirudin-attached spacer may terminate in a high affinity ligand, such as a biotin molecule, which would then bind to its high affinity receptor molecule, such as avidin, that is itself covalently bound to the surface. Or, where the high affinity receptor molecule has multiple binding sites for its ligand, the receptor molecule may be attached to the surface by binding to one of its specific ligands that is itself attached to the surface by any of the covalent or non-covalent binding means or combination of binding means just described.
The hirudin of this invention may be attached to materials which are useful in the production and use of medical products, systems and devices. Such materials include naturally occurring, genetically derived and synthetic materials. Naturally occurring materials include tissues, membranes, organs and naturally occurring polymers. one example of a genetically derived material is poly-beta-hydroxybutyrate.
Such naturally occurring, genetically derived and synthetic polymers homo- and co-polymers derived from one or more of the following: 1-olefins, such as ethylene, propylene, tetrafluoroethylene, hexafluoropropylene, vinylidene difluoride, etc.; vinyl monomers, such as vinyl chloride, styrene, maleic anhydride, methylmethacrylate, acrylonitrile, etc.; ethers, such as ethylene, tetramethylene, etc.; esters, such as ethylene-terephthalate, bisphenol A-terephthalate, etc.; carbonates, such as bisphenol A, 4,4-dihydroxybiphenylene, etc.; amides (including ureas and urethanes), such as nylons, segmented polyurethanes, proteins, etc.; saccharides, such as glucose, glucosamine, guluronic acid, sulfated glycoseaminoglycans, agarose, alginic acid, etc.; siloxanes, such as dimethyl siloxane, 3-aminopropyl siloxane, etc. Polymers which are useful in this invention may include biodegradable, partially biodegradable and non-biodegradable polymers. Other useful materials include metals, such as aluminum and stainless steel; glass, ceramics, and carbon in its various forms.
The choice of the material to which hirudin or its analogs may be attached generally depends on the function of the medical device or product incorporating that material. Given a specific material or combination of materials in a single device, or system of multiple devices, a surface attachment strategy is formulated for hirudin, following principles and iogic well known to those skilled in the art. The above considerations ultimately determine the chemical group selected for the free and of the spacer attached to hirudin, and the subsequent members of the chain that retains hirudin at the material surface.
It is understood that the mechanisms described for attachment of hirudin and its analogs to surfaces in accordance with the present invention are equally applicable to their attachment to mass-increasing molecules for the purpose of prolonging their in vivo half-life. Examples of such mass-increasing molecules include, but are not limited to, polymers such as polyethylene glycol or oxide, polyvinylpyrrolidone or the polyglucoses; and macromolecules such as serum albumin, avidin, heparin, or hydroxyethyl starch. Large, globular mass-increasing molecules may be attached to hirudin by means of a long spacer that provides hirudin with sufficient spatial freedom to achieve its inhibitory position on thrombin; or, in other words, steric interference between the mass-increasing molecule and thrombin must not block the presentation of hirudin to its binding sites on thrombin. Polyethylene glycol or oxide chains, which are generally attached directly to the macromolecule of interest, demonstrate a mass-increasing effect beyond their actual mass because of the larger excluded volume subtended by their highly mobile chains. See: Knauf, M. J. et al., J. Biol. Chem. 263 pp. 15064 to 15070 (1988). Site-directed PEGylation of hirudin at the finger region Tyr positions the mobile polyethylene glycol/oxide chains on the side of the hirudin molecule opposite from its thrombin-binding site.
EXAMPLE 1
Production of rHV2-Phe 3 Gln 33 Tyr 35 Lys 47 Asp 63 HV2 has Tyr at positions 3 and 63. In accordance with the present invention, the reactive functional Tyr 3 is replaced with nonreactive functional Phe, and the reactive functional Tyra is replaced with nonreactive functional Asp. These replacements do not reduce the thrombin binding activity of the molecule. Reactive nonfunctional Tyr is then substituted for the native nonreactive nonfunctional Lys at position 35 in the finger region. This change also does not eliminate the thrombin binding activity of the molecule but it does provide a site where Tyr is available for reaction. Aen at position 47 may be changed to Lys as described in European Patent Application No. 87402696.6 to improve the activity of the antithrombogenic analog.
The hirudin analog HV2 Phe 3 Gln 33 Tyr 35 Lys 47 Asp 63 was prepared by the following methods:
A. Starting Material
Starting material was phage M13TG4892. This phage (a derivative of M13TG131) contains an expression block consisting of:
a. a slightly modified version of the MF αl promoter (the 5' EcoRI site was converted to a SphI site, and the internal BglII site was destroyed by a treatment with the Klenow fragment of E. coli DNA polymerase I),
b. a variant of the yeast BGL2 signal peptide (BGL2-Val 7 ) and
c. the rHV2-Lys 47 coding sequence.
B. rHV2-Lys 47 Asp 63
By site directed mutagenesis (oligonucleotide OTG2942; Amersham site directed mutagenesis kit #RNP 1523) on single stranded DNA (ssDNA) of M13TG4892 the codon TAT (Tyr 63 ) was exchanged for GAC (Asp) resulting in M13TG5884. The mutation was verified by sequencing the entire hirudin coding sequence (sequencing primer: OTG2387). rHV2-Lys 47 Asp is encoded in M13TG5884.
C. rHV2-Phe 3 Gln 33 Tyr 35 Lys 47 Asp 63
By site directed mutagenesis (oligonucleotides OTG2993: Tyr 3 to Phe and OTG2994: Asn 33 to Gln, Lys 35 to Tyr) on ssDNA of M13TG5884 the codons TAT (Tyr 3 ) were exchanged for TTC (Phe), AAT (Asn 33 ) for CAA (Gln), and AAG (Lys 35 ) for TAC (Tyr) at the same time resulting in M13TG6844. The mutations were verified by sequencing the entire hirudin coding sequence (FIG. 1). rHV2-Phe 3 Gin 33 Tyr 47 Lys 47 Asp 63 is encoded in M13TG6844.
D. Assembly of the expression vector pTG6864
The yeast basic expression vector pTG3828 (pBR322, 2 micron, URA3-d, PGK1 transcriptional terminator) was used to assemble the expression plasaid. Vector pTG3828 and M13TG6844 (dsDNA) were digested with SphI and SalI and ligated. The ligation mixture was used to transform E. coli strain BJ5183 to ampicillin resistance (Ap R ). Plasmid DNA was isolated from six Ap R clones, and the PstI restriction profile of each preparation analyzed. Corresponding to the expected restriction profile clone N°l was used for a CsCl purification of pTG6864 (alkaline lysis protocol). Structure of the purified plasmid was verified again by digestion with PstI and SphI+Sal1.
pTG6864: the yeast rHV2-Phe 3 Gln 33 Tyr 35 Lys 47 Asp 63 production plasmid (FIG. 2) is an E. coli-yeast shuttle vector with the following elements:
i. a bacterial segment, which is derived from E. coli plasmid pBR322, harboring a bacterial origin of replication (ori), and the bacterial selection marker for ampicillin resistance (Ap R )
ii. a segment of the yeast 2 micron episome with its origin of replication
iii. a promoter- and terminator-deleted version of the yeast URA3 gene (URA3-d) serving as a yeast selectable marker
iv. a modified version of the yeast MF αl promoter
v. a sequence coding for a variant form of the yeast BGL2 derived signal peptide serving as a secretion signal fused in frame to
the rHV2-Phe 3 Gln 33 Tyr 35 Lys 47 Asp 63 coding sequence, and
a Segment of the yeast PGK gene serving as a transcriptional terminator
Thus, pTG6864 confers ampicillin resistance to transformed E. coli cells; and it renders transformed yeast ura3 auxotrophic strains prototrophic for uracil (Ura + ).
The DNA sequence encoding rHV2-Phe 3 Gln 33 l Tyr 35 Lys 47 Asp 63 (FIG. 1) has been verified after site directed mutagenesis, and is contained in M13TG6844 and pTG6864, respectively.
E. Transformation of Yeast Strain TGY48.1
Plasmid pTG6864 has been used to transform Saccharomyces cerevisiae strain TGY48.1 MAT αura3his 3 pral prbl prcl cpsl to uracil prototrophy (lithium acetate protocol; 5.5 μg of plasmid DNA per 1.3×10 8 cells). TGY48.1 is a haploid strain of mating type α(MAT α) with a nonreverting allele of the URA3 gene (ura3-Δ5) as selectable marker. After four days incubation at 30° C. three Ura + clones were obtained. Clone N°1 was further analyzed.
F. Hirudin Production from TGY48.1/pTG6864
Ura + prototrophy of clone No°1 was verified. Clone N°1 was grown at 30° C. in an Erlenmeyer flask (250 ml) under selective conditions for 48 hrs to a final cell density (measured as absorbance at 600 nm, where A 600 =1 corresponds to 10 7 cells/ml) of 10 to 12. Cells were centrifuged out, and culture supernatants were tested for thrombin inhibition in a kinetic assay using the chromogenic substrate, Tos-Gly-Pro-Arg-4-nitroanilide acetate (Chromozym TH, Boehringer Mannheim, Germany). Hirudin production was expressed as the anti-thrombin activity of yeast culture supernatant (ATU/ml) normalized to the A 600 of the culture.
EXAMPLE 2
Once an analog is prepared having a nonfunctional Tyr available, known methods may be employed to bind that Tyr to a spacer.
Hirudin containing an aryl amine on tyrosine (Hirudin-Tr-N.) was prepared by nitration followed by reduction (J. F. Riordan and B. L. Vallee. Methods Enzymol. 25 pp. 515-521 (1972)). The nitration reaction was performed at room temperature in 0.01 M sodium phosphate, pH 8.3, by mixing hirudin (0.7×10 -6 M) with a ten-fold molar excess of ethanolic tetranitromethane. The reaction was monitored by absorbance at 428 nanometers for 2 hours, then terminated by gel filtration on BIO-GEL®(cross linked polyacrylamide)P-6DG pre-equilibrated with the sodium phosphate buffer. Hirudin-Tyr-NO 2 was reduced to hirudin-Tyr-NH 2 by adding a ten-fold molar excess of sodium dithionite in the sodium phosphate buffer and incubating until the nitrophenol absorbance at 428 nanometers disappeared. The aryl anino(tyrosine) hirudin was separated from excess sodium dithionite by desalting on BIO-GEL® P-6DG pre-equilibrated with 0.04 M sodium acetate, pH 5.0, concentrated and stored at -20° C.
EXAMPLE 3
Attachment of SPDP to Hirudin-Tyr-NH 2
Sulfo-LC-SPDP (Sulfosuccinimidyl 6-[3-(2-pyridyldithio) propionamido] hexanoate) was attached to hirudin containing an aryl amine on tyrosine by the following method: To hirudin-Tyr-NH 2 , (0.143×10 -6 M) in 0.04 M sodium acetate, pH 5.0, was added a ten-fold molar excess of Sulfo-LC-SPDP and the solution agitated for 2 hours at room temperature. Excess Sulfo-LC-SPDP was removed by desalting on BIO-GEL P-6DG pre-equilibrated with 0.01 M sodium phosphate, pH 7.0, and the SPDP-hirudin concentrated and stored at -200° C. The LC-SPDP-hirudin was incubated before use with a 3-fold molar excess of dithiothreitol in 0.04 M sodium acetate, 0.005 M EDTA, pH 4.5, until absorbance at 343 nanometers reached a plateau, then the LC-SPDP-hirudin was purified by desalting on BIO-GEL®P-6DG.
EXAMPLE 4
Binding N-Acetyl-homocysteine to Hirudin-Tyr-NH 2
N-Acetyl-homocysteine was attached to hirudin that contained an aryl amine on tyrosine by the following method: Into a solution of hirudin-Tyr-NH, (0.143×10 -6 M) in 0.04 M sodium acetate, pH 5.0, was mixed a ten-fold molar excess of N-acetyl-homocysteine thiolactone (MiTL) in methanol and reaction continued for two hours with constant agitation at room temperature. Excess AHTL was removed by desalting on BIO-GEL®P-6DG pre-equilibrated with 0.01 M sodium phosphate, pH 7.0, and the N-acetyl-homocysteine-hirudin concentrated and stored at -20° C. All reactions were performed under a stream of nitrogen gas.
EXAMPLE 5
Surface Immobilization of Hirudin-Spacer Conjugates by Thiol Ethers
Sulfo-LC-SPDP- or N-acetyl-homocysteine-hirudin Was attached to surfaces by formation of a thiol ether bond. In brief, an agarose gel bearing either a long-chain iodoacetyl group (0.5 ml SULFOLINK GEL® (cross linked agarose), Pierce) or a maleimide (SulfoSMCC: Sulfosuccinimidyl 4- (maleimidomethyl) cyclohexane-1-carboxylate) was reacted with either of the above hirudin derivatives (1.43×10 -6 M in 0.05 M Tris-HCl, 0.005 M EDTA-Na, pH 8.5) for 1 hour at room temperature. The gel was washed with 0.05 M Tris, 0.005 M EDTA-Na, pH 8.5; incubated with 0.05 M cysteine, 0.05 M Tris, 0.005 M EDTA-Na, pH 8.5 for 1 hour; washed with 1 M NaCl; then equilibrated with physiological saline, pH 7.2.
EXAMPLE 6
Binding of NHS-LC-Biotin to Hirudin-Tyr-NH 2
NHS-LC-biotin (Sulfosuccinimidyl-6-(biotinamido)hexanoate) was attached to hirudin containing an aryl amine on tyrosine by the following method: To hirudin-Tyr-NH 2 (0.143×10 -6 M) in 0.04 M sodium acetate, pH 5.0, wan added a ten-fold molar excess of NHS-LC-biotin and the solution agitated for 2 hours at room temperature. Excess LC-biotin was removed by desalting on BIO-GEL® P-6DG.
EXAMPLE 7
Attachment of Hirudin-Spacer Conjugates by Avidin-Biotin Complexes
Hirudin-Tyr-LC-biotin conjugates were bound to soluble avidin, avidin-coated polystyrene beads (FLUORICON particles, Baxter Healthcare) or avidin-coated silicone rubber tubing at a 1:1 molar ratio by incubating in 0.02 M sodium phosphate pH 7.4 for 1 hour at room temperature.
EXAMPLE 8
Anti-thrombin Activity of Attached Hirudin Analogs
The thrombin inhibition activity of rHV2 Phe 3 Gln 33 Tyr 35 Lys 47 Asp 63 : (H-Tyr), and its derivatives, including spacer molecules ranging from 200 to 67,000 molecular weight, were determined by incubating them with human thrombin, then measuring the residual thrombin activity as the initial velocity of amidolysis of H-D-Phenylalanyl-L-pipecolyl-L-arginine-p-nitroanalide dihydrochloride (Kabi, S-2238), where zero thrombin activity was 100% inhibition. Aliquots containing 0.13-1.3 picomoles of hirudin as (a) the analog, H-Tyr, (b) the analog with an aryl amine on Tyr 35 : (H-Tyr-NH2), (c) the analog with LC-biotin attached to the tyrosyl amine: (H-Tyr-B), (d) the biotinylated analog attached to soluble avidin: (H-Tyr-B-Av), (e) the biotinylated analog attached to avidin-coated beads: (H-Tyr-B-Av-Beads), (f) the analog with N-acetyl-homocysteine attached to the tyrosyl amine and to SULFOLINK GEL® (H-Tyr-AH-SLG), and (g) the analog with LC-SPDP attached to the tyrosyl amine and to SULFOLINK GEL® (H-Tyr-SPDP-SLG); were reacted with 1.3 picomoles of human alpha-thrombin in 0.05 M Tris-HCl, pH 7.4, 0.1% bovine serum albumin, for 1 hour at 22° C.; then centrifuged. Aliquots of the supernatants were diluted with the Tris-BSA buffer and the reaction initiated by addition of S-2238. Reaction velocities were monitored at 410 nanometers and used to determine thrombin activity. Moles of hirudin analog and its derivatives in each assay were determined by radioiodinated hirudin analog tracer. The analog H-Tyr retained virtually all of its specific thrombin inhibition activity during insertion of an asine into the tyrosine ring, attachment of LC-biotin spacer, and when bound through the spacer to soluble avidin or to avidin-coated beads. However, when the analog was attached to a surface via the shorter spacer Molecules diminished specific thrombin inhibitory activity was observed (Table I).
TABLE I______________________________________ Thrombin Inhibition Hirudin Analog (Specific Activity: % of H-Tyr)______________________________________H-Tyr 100 H-Tyr-NH.sub.2 99 H-Tyr-B 99 H-Tyr-B-Av 98 H-Tyr-B-Av-Beads 97 H-Tyr-AH-SLG 6 H-Tyr-SPDP-SLG 61______________________________________
EXAMPLE 9
Preparation and Anti-thrombin Activity of Hirudin-Tyr-PEG Adduct.
To provide a soluble hirudin of increased mass similar to the biotinylated hirudin attached through a spacer to soluble avidin as described in Examples 7 and 8, methoxypolyethylene glycol (5 kD) was directly bound to
__________________________________________________________________________# SEQUENCE LISTING - - - - (1) GENERAL INFORMATION: - - (iii) NUMBER OF SEQUENCES: 3 - - - - (2) INFORMATION FOR SEQ ID NO:1: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 8 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: peptide - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (v) FRAGMENT TYPE: N-terminal - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1: - - Leu Gly Ser Ala Gly Lys Gly Asn 1 5 - - - - (2) INFORMATION FOR SEQ ID NO:2: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 204 base - #pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: DNA (genomic) - - (iii) HYPOTHETICAL: NO - - (iv) ANTI-SENSE: NO - - (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 1..195 - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: - - ATT ACG TTC ACA GAC TGC ACA GAA TCG GGT CA - #A AAT TTG TGC CTCTGC 48 Ile Thr Phe Thr Asp Cys Thr Glu Ser Gly Gl - #n Asn Leu Cys Leu Cys 1 5 - # 10 - # 15 - - GAG GGA AGC AAT GTT TGC GGT AAA GGC AAT AA - #G TGC ATA TTG GGT TCT 96 Glu Gly Ser Asn Val Cys Gly Lys Gly Asn Ly - #s Cys Ile Leu Gly Ser 20 - # 25 - # 30 - - CAA GGA TAC GGC AAC CAA TGT GTC ACT GGC GA - #A GGT ACA CCG AAA CCT144 Gln Gly Tyr Gly Asn Gln Cys Val Thr Gly Gl - #u Gly Thr Pro Lys Pro 35 - # 40 - # 45 - - GAA AGC CAT AAT AAC GGC GAT TTC GAA GAA AT - #T CCA GAA GAA GAC TTA192 Glu Ser His Asn Asn Gly Asp Phe Glu Glu Il - #e Pro Glu Glu Asp Leu 50 - # 55 - # 60 - - CAA TGAAAAATG - # - # - # 204 Gln 65 - - - - (2) INFORMATION FOR SEQ ID NO:3: - - (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 65 amino - #acids (B) TYPE: amino acid (D) TOPOLOGY: linear - - (ii) MOLECULE TYPE: protein - - (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: - - Ile Thr Phe Thr Asp Cys Thr Glu Ser Gly Gl - #n Asn Leu Cys Leu Cys 1 5 - # 10 - # 15 - - Glu Gly Ser Asn Val Cys Gly Lys Gly Asn Ly - #s Cys Ile Leu Gly Ser 20 - # 25 - # 30 - - Gln Gly Tyr Gly Asn Gln Cys Val Thr Gly Gl - #u Gly Thr Pro Lys Pro 35 - # 40 - # 45 - - Glu Ser His Asn Asn Gly Asp Phe Glu Glu Il - #e Pro Glu Glu Asp Leu 50 - # 55 - # 60 - - Gln 65__________________________________________________________________________
hirudin through an aryl amine on tyrosine by reacting hirudin-Tyr-NH 2 , 0.143×10 -6 M in 0.04 M sodium acetate, pH 5.0, with a fifty-fold molar excess of methoxypolyethylene glycol-succinimidyl succinate (MPEGSS) for 30 min at room temperature. The reaction was stopped by addition of excess glycine at pH 7 to inactivate residual MPEGSS. SDS-PAGE analysis of the reaction products demonstrated complete transformation of hirudin-Tyr-NH to its PEG adduct. The adduct retained 90% of the thrombin inhibitory activity of the hirudin-Tyr-NH 2 ; starting material when evaluated by the chromogenic assay described in Example 8. This illustrates that mass-increasing PEG derivatives can be directly attached to rHV2-Phe 3 Gln 33 Tyr 35 Lys 47 Asp 63 through an aryl amine in the phenolic ring of Tyr 35 without significant loss of biological activity.
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A tyrosine-substituted hirudin analog has antithrombogenic activity. Further simultaneous reaction at native tyrosine residues is prevented by mutation at those sites to encode nonreactive amino acids. Several novel strategies for coupling the hirudin analog to solid surfaces while simultaneously conserving antithrombogenic activity are disclosed.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to the field of protecting building apertures such as door and window openings from hurricanes, wind-blown debris, gales, rain, and vandals. More specifically it concerns very low cost, low profile extrusion brackets designed specifically for installation during original building construction in combination with a variety of conventional manufactured windows, and hinged or sliding glass doors in conventional building structures, and the use of those brackets with adjustable, lightweight isosceles trapezoidal corrugated panels for protection. The goal is to render building apertures compliant with the International Building Code (“I.B.C.”) even though those building apertures employ fenestration products that are unmodified for I.B.C. compliance.
[0003] 2. Description of the Prior Art
[0004] Investigations of damage from major hurricanes such as Hurricane Andrew indicate that most of the damage to a residence structure is from the wind and wind borne missiles that break windows and allow rain and wind into the structure. In south Florida, where Hurricane Andrew caused unprecedented destruction, nearly all residential structures are masonry, cinder block structures with wooden gable ends and roofs. Once the wind reaches the interior of such structures, the resulting pressure tends to blow out the windows, gable ends and/or lift the roof off the structure. This is due in part to the Bernoulli effect, where wind blowing around and over a building causes lower pressure than the high pressure air inside, and sucks out a window, gable end, or roof. Just as an airplane rises due to the pressure differential of faster air moving over a wing to create a low pressure, compared to the high pressure of slower moving air under a wing, so too do the weakest structures in a home tend to be blown out due to the Bernoulli effects of wind blowing around and over the building. Of course, window and door shutters of adequate design can help keep the wind and rain from entering a home during a hurricane or strong storm.
[0005] Historically, upon the approach of a hurricane many homeowners have nailed plywood sheets over building apertures seeking to prevent wind-driven rain and debris from breaking into the structure's interior. Nailing sheets of plywood over every building aperture is difficult on many homes, and can take too much time to complete before the storm hits. Moreover, many homeowners are reluctant to drive nails into their window frames or do not want to be on a ladder during high winds. An individual has difficulty in holding up a large, heavy piece of plywood and nailing it in at the same time, especially as the wind velocity increases. In addition, when a hurricane approaches, building suppliers almost invariably run out of plywood.
[0006] As a result of recent hurricanes making landfall and devastating numerous structures, especially as Hurricane Andrew did, many building codes were found to be inadequate to protect structures and their occupants. Multiple state and federal agencies came together with a uniform goal to standardize building methods. Specifically, the merger of the Southern Building Code Congress International (SBCCI) with both the Building Officials and Code Administrators (BOCA) and the International Conference of Building Officials (ICBO) resulted in the International Code Council (ICC). The ICC has created a series of uniform international building codes including one that applies to residential structures, which will be referred to in this document as the International Building Code (“I.B.C.”). Accordingly, reference to the I.B.C. hereinafter specifically means compliance with the hurricane protection aspects of the I.B.C. for residential structures.
[0007] The first state to adopt this new I.B.C., in 2002, was Florida which was shortly followed by North Carolina. The code specifically required hurricane protection for all residential structures within a certain distance of coastal waters.
[0008] The economic impact of the new code on fenestration products was the cause of the present invention. One of its prominent features is that it allows fenestration manufacturers to continue production of their products with little or no structural design changes while compliance with the I.B.C. can still be achieved. A builder who is installing a window, door or sliding glass door is required under the I.B.C. to have impact protective apparatus protecting the glazed (glass covered) building apertures. The builder or installer of the window can place the inventive brackets on the window prior to installation and then secure hurricane protection panels to the exterior side of the window without interfering or changing the design of the window. Other advantages are: consolidating products prior to installation reduces labor costs, providing a user friendly easily installed shutter, installation can be within the opening of the building's structure with masonry structures and in such instances does not extend beyond such opening, there's no need for screws or bolts, headers or sills to be fastened to the exterior surface of a building, with this combination system decorative or ornamental designs can once again be placed around the window's perimeter, and the use of the brackets actually strengthens the fenestration products.
[0009] There is a great profusion of prior art in this field. Most of it relates to hurricane and storm shutters that are applied to building apertures after the building is constructed, and virtually all of it deals with the masonry structures common only to South Florida, and not the wood frame structures that predominate the entire rest of the United States.
[0010] A first example is Hill, U.S. Pat. No. 5,487,244, for a shutter system with a downwardly facing channel bolted to the exterior of the structure as a header and using an angle iron sill in combination with isosceles trapezoidal corrugated panels disposed between the header and the sill to protect the building aperture. A very similar reference is Poirier, U.S. Pat. No. 6,209,263, which also employs a downwardly facing channel as a header and an angle iron sill between which are disposed isosceles trapezoidal corrugated panels. Another example is DiVeroli, U.S. Pat. No. 6,189,264, which discloses a storm shutter system capable of being installed from the interior of the structure through the building aperture and which uses an upwardly facing channel at the sill and either downwardly facing channel as a header or a bracket, in each case being attached to the exterior of the building. Other examples are Knezevich, et al., U.S. Pat. Nos. 6,021,839 and 6,122,868, which use other complex extrusions at the header and the sill which extrusions are bolted to the exterior of a structure. A further example is Thompson, et al., U.S. Pat. No. 6,205,713 which uses brackets attached to the exterior of the structure.
[0011] A number of the prior art references include exterior frames and utilize louvers to cover the building aperture. Examples are Horn et al., Patent Application Publication No. U.S. 2002/0056230 A1 and Biggers, U.S. Pat. No. 6,148,895. Some of the references employ complex structures such as Mullet et al., U.S. Pat. No. 6,341,639. See, for example, the elaborate extrusions shown in FIG. 13 thereof. Also see FIGS. 35-39A thereof. Another example of a reference having exceptionally complex extrusions is Fullwood, U.S. Pat. No. 5,857,298. See, for example, FIGS. 3-5 , 7 - 10 , 12 - 15 , 17 - 20 , and especially FIG. 28 .
[0012] As will be more fully seen hereinafter, the present invention includes headers and sills that are simple extrusions intended to be installed at the time of original building construction to produce in combination with isosceles trapezoidal corrugated panels a very unobtrusive, very simple, and very inexpensive hurricane shutter. While the present invention differs from the overwhelming majority of the profusion of prior art that is intended for installation after construction of the building is complete, the prior art is not devoid of references teaching storm shutters intended to be installed as part of original building construction. Examples are Fullwood, U.S. Pat. Nos. 5,857,298 and 5,941,031, and Biggers, U.S. Pat. No. 5,540,018. Biggers '018 adopts the same notions of the present invention of having brackets installed with windows at the time of original building construction to save time and money and using isosceles trapezoidal corrugated panels with the brackets, but the extrusions are much more complex than those featured in the present invention, making them much more expensive, and sacrificing the goal of the present invention in which the conventional fenestration products require little or no modification to be compatible with the brackets used for the hurricane shutters. See, for example, FIGS. 6-11 , and 13 - 17 .
SUMMARY OF THE INVENTION
[0013] Bearing in mind the foregoing, it is a principal object of the present invention to provide a hurricane shutter apparatus for installation in a building at the time of its original construction that will result in compliance with the International Building Code (“I.B.C.”) using conventional fenestration products in combination with simple, inexpensive extrusions as header and sill brackets to support in storm conditions simple, inexpensive isosceles trapezoidal corrugated panels.
[0014] It is a related principal object of the invention to enable the reduction of labor costs in constructing I.B.C. compliant structures using conventional fenestration products by combining simple, inexpensive extrusions with those conventional products prior to installation of the combinations in building apertures during original construction.
[0015] Another related object of the invention is to achieve the installation of hurricane shutter supporting brackets for I.B.C. compliant structures that use conventional fenestration products without attaching those brackets using screws or bolts on the exterior surface of a building or where the brackets are exterior to the building.
[0016] An additional object of the invention is to install at original building construction header and sill brackets for use with conventional fenestration products in a I.B.C. compliant building that is completely disposed within a conventionally sized building aperture such that decorative or ornamental designs can once again be placed around the window's perimeter.
[0017] A further object of the invention is to provide a user friendly easily installed shutter which does not extend beyond the building aperture in the case of masonry structures.
[0018] A related principal object of the invention is to employ such headers and sills that are of simple, low profile design.
[0019] A further object of the invention is to provide such header and sill extrusions that accommodate both buildings constructed from masonry with conventional flange windows, and buildings constructed with wood frames having conventional fin windows.
[0020] Another object of the invention is to provide a hurricane shutter apparatus that has a minimum profile designed to have the least effect on the appearance of the building and the building apertures when not in use.
[0021] A further object of the invention is to provide a hurricane shutter apparatus that has been tested as a large missile impact protective system in accordance with the I.B.C. and the Florida Building Code 2001 Nonhigh Velocity Hurricane Zones, and further has been tested for Large Missile Impact Resistance in conformance with ASTM-E 1886-97, 1996-99 and for uniform load structural test ASTM E-330.
[0022] Another object of the invention is the use of strong and inexpensive isosceles trapezoidal corrugated panels that are small, lightweight, and easy to install even in windy conditions, and which take up minimal storage space as the panels nest one into the other.
[0023] A further object of the invention it is to utilize a header, which when installed during original building construction in a wood frame structure directs water from rain against the side of the building away from the window even when the shutter panels are not in use.
[0024] An additional object of the invention is to employ header and sill extrusion designs that provide adequate spacing away from fenestration products for the installation of isosceles trapezoidal corrugated panels.
[0025] One more object of the invention is to utilize a sill that employs a recessed slide bolt track that is unobtrusive and has no projecting parts to create a tripping hazard when used with a building aperture furnishing ingress and egress from the building.
[0026] A further object of the invention is to provide with wood frame residential structures a rain hood or watershed with a header bracket that is embedded in the wall and that forces water away from the window to prevent leakage, mildew and rot.
[0027] Another object of the invention is to strenghen fenestration products by the application of the inventive brackets.
[0028] Other objects and advantages will become apparent to those skilled in the art upon reference to the following descriptions and the appended drawings.
[0029] In accordance with a principal aspect of the invention there are provided two pairs of brackets for installation at the time of original building construction. The first pair are designed to be a header and sill with wood frame buildings and fin windows such are in use in most of the United States, except South Florida. As noted above, the prior art appears devoid of references that teach hurricane shutters for wood frame residential structures. The second pair are designed to be a header and sill with masonry buildings and flange windows such as are in almost unanimous usage in South Florida. In the following descriptions of the inventive brackets, the terms “inwardly” and “inside” refer to a direction toward the interior of the building on which the brackets are installed during original construction. The terms “outwardly” and “outside” refer to a direction toward the exterior of the building.
[0030] The first header bracket is comprised of a downwardly facing channel having a channel web, inner channel flange and outer channel flange. The lower edge of the outer channel flange includes a flare. The channel web is co-planar with a horizontal inwardly projecting arm. Co-planar with the inwardly projecting arm inside of the inner channel flange is disposed a window element web. That terminates with a downwardly depending window element flange. The window element flange outer surface is a contact point for a first window element known as a window flange. The window element web doubles as a spacer between the window and where the corrugated panels are inserted into the downwardly facing channel. On the inside of the window element flange and co-planar with the horizontal inwardly projecting arm is a horizontal window depth spanner. The window depth spanner forms a space between the first window element and a second window element described below. At the inside edge of the window depth spanner and disposed at right angles thereto is a vertical arm. Finally, the vertical arm is at right angles to a window element ridge inside the top edge of the vertical arm. This provides for a window element recess for insertion of the second window element, a window fin, such as already exists with conventional fin windows, which are used in wood frame residential structures throughout the United States.
[0031] The first sill bracket is comprised of a recessed bolt head track body containing a recessed bolt head track with a vertical track aperture, vertical track upper face, and vertical track lower face. At right angles to the top of the upper track face is a horizontal track body top. It serves as a resting point for a first window element, the window flange. The horizontal track body top also doubles as a spacer between the window and where the corrugated panels are bolted to the recessed bolt head track body. At the inside edge of the track body top and at right angles thereto is a vertical window depth spanner wall. At the top edge of the window depth spanner wall and at right angles thereto is a horizontal window depth spanner. At the inside edge of the window depth spanner is a vertical downwardly projecting arm. At the bottom of the downwardly projecting arm is an inwardly oriented window element ridge, which creates a window element recess between the downwardly projecting arm and the building structure for the insertion of a second window element, a window fin, such as already exists with conventional fin windows.
[0032] The second header bracket is comprised of a downwardly facing channel having a channel web, inner channel flange and outer channel flange. The lower edge of the outer channel flange includes a flare. The channel web is co-planar with a horizontal inwardly projecting arm to interface with the building structure. On the inside of the inner channel flange and part way down the inner channel flange is a horizontal spacer web. At the inside of the spacer web is a downwardly depending window element wall. Co-planar with the spacer web and inside of the window element wall is a window element ridge. The window element ridge creates a window element recess between the building and the window element wall for the insertion of a window element, a window flange, such as already exists with conventional flange windows.
[0033] The second sill bracket is comprised of a recessed bolt head track body containing a recessed bolt head track with a track aperture, track upper face, and track lower face. Co-planar with the track lower face is a horizontal inwardly projecting arm to interface with the building structure. Disposed inwardly from the bolt head track is a vertical window element receiving slot for the insertion of a window element such as already exists with conventional flange windows. The slot is formed between the recessed bolt head track body and a parallel vertical slot wall. Co-planar with the slot wall and depending vertically downwardly from beneath the horizontal plane of the inwardly projecting arm is the downwardly projecting arm. At the bottom of the downwardly projecting arm is a base member having a stucco ground ridge.
[0034] In accordance with a secondary aspect of the invention, there are provided a plurality of isosceles trapezoidal corrugated panels and wingnut bolts. The panels are to be disposed between the header and sill brackets when a hurricane or other storm threatens, and bolted firmly in place using the bolt heads disposed in the recessed track of the sill bracket, the bolts' shafts disposed through perforations in the lower ends of the panels, and tightened in place using the wingnuts.
[0035] The panels when examined in a top or bottom view show most corrugations are conventionally sized, but with one lateral edge corrugation on each panel having a greater width than the conventionally sized corrugations. This results in the ability to laterally adjust the panels' positions with respect to each other and thus adjust the width of the building aperture to be covered.
[0036] In accordance with a tertiary aspect of the invention, there are provided a plurality of alternate embodiment brackets that will be described in similar terms to the foregoing in the Detailed
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] In accordance with a final aspect of the invention, the installation of the header bracket in a wood frame residential structure at the time of its construction leads to substantial unexpected advantages to the resistance of the structure and fin windows to conventional rain. A fin window (the type employed with wood frame residential structures) is attached the building aperture by having its fins fastened to the substrate of the wall surrounding the building aperture through a vapor barrier. The substrate is the material that is nailed to the studs that are inside every wood frame wall, the substrate frequently being plywood. The vapor barrier is applied over the substrate, and is usually polyethylene sheeting. Since the fins on a fin window are roughly half way through the thickness of the window frame, the outer half of the window frame is outside of the substrate and vapor barrier, and the channel around the outside of the frame that is outside of the substrate and vapor barrier is a candidate for the collection of rain water, even though the building's facing such as shingles, faux brick, aluminum or wood siding, etc. is applied on top of the vapor barrier. When rain water accumulates in this channel, it can access the window itself through screw holes in the window frame. But when the header bracket used with wood frame buildings is installed with the fin window, its window element ridge is pressed tightly against and sealed to the vapor barrier preventing any water from reaching the window. Sealing is accomplished using seam seal tape or the like. The downwardly facing channel web of the header bracket then forces rain water away from the top of the window, acting as a rain hood or watershed.
[0038] In terms of the method of construction and installation of the header bracket and window, the wall is constructed of studs with the substrate then applied thereto. Vapor barrier is then applied over the substrate and taped into the window apertures. The header bracket is combined with the fin window and both are attached to the substrate through the vapor barrier. Both are then sealed to the vapor barrier using seam seal tape or the like. Attaching the header bracket to the substrate and then sealing prevents any water from reaching the window frame, with all water being forced away from the top of the window by the downwardly facing channel web and outer flange. In effect the header bracket is embedded into the wall to provide complete rain hood or watershed protection to the fin window. This is vitally important to prevent eventual leakage, mildew and rot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Various other objects, advantages, and features of the invention will become apparent to those skill in the art from the following discussion taken in conjunction with the appended drawings, in which:
[0040] FIG. 1 is a perspective view of a building under construction having six building apertures, five windows and one hinged door. Two windows ready for installation with the header and sill brackets in place on the window. Two windows are shown installed with the header and sill brackets in place. One window is shown installed with hurricane shutter panels in place to protect the building aperture.
[0041] FIG. 2 is an exploded perspective view of header and sill brackets above and below a typical window with partial paneling to the right side of the window.
[0042] FIG. 3 is a perspective view of a building having six building apertures, four windows, one hinged door and one sliding glass door, all of which are covered with the inventive hurricane shutter apparatus. All the building apertures are protected by the preferred embodiment of a header and a sill bracket equipped with vertically disposed isosceles trapezoidal corrugated panels. The sliding glass door is protected with alternative embodiment vertical brackets with horizontal hurricane protection storm panels. One hinged door uses an alternative embodiment exterior wall mounted header and sill supporting the isosceles trapezoidal corrugated panels.
[0043] FIG. 4 is an exploded perspective view of a typical sliding glass door with vertical brackets to be attached to the sliding glass door jambs, with partial paneling beneath the sliding glass door.
[0044] FIG. 5 is a perspective view of a first header bracket with a downwardly facing channel providing a location for the placement of the top ends of hurricane protection panels. The bracket includes a spacer to form a space between the window and where the corrugated panels are inserted into the downwardly facing channel. On the inside of the spacer is a window element groove for the insertion of a first window element such as already exists with conventional fin windows. At the inside edge of the window element web and disposed at right angles thereto is a vertical arm that interfaces with the building structure. Finally, bracket includes a window element recess for insertion of a second window element such as already exists with conventional fin windows.
[0045] FIG. 6 is a perspective view of a first sill bracket with a recessed bolt head track. Disposed inwardly from the bolt head track is a spacer. Disposed inwardly from the spacer is a vertical downwardly projecting arm to interface with the building structure. At the bottom of the downwardly projecting arm is an inwardly oriented window element ridge, which creates a window element recess between the downwardly projecting arm and the building structure for the insertion of a window element such as already exists with conventional fin windows.
[0046] FIG. 7 is an exploded view of the brackets of FIGS. 18 and 19 with a conventional fin window and with a hurricane shutter panel in proximity to its installation position and with a typical bolt and wingnut used to secure the panel upon installation to the sill bracket.
[0047] FIG. 8 is an assembly drawing showing the elements of FIG. 7 completely assembled on a wood frame building.
[0048] FIG. 9 is an exploded bottom view of a sill bracket and hurricane protection storm panels in proximity thereto.
[0049] FIG. 9A is a broken back elevation view of the bottom edge of a single hurricane protection storm panel showing how it is perforated for insertion of bolts with a slot for the adjustment of the lateral position of the adjoining panel to accommodate different building aperture widths.
[0050] FIG. 10 is a perspective view of a second header bracket with a downwardly facing channel providing a location for the placement of the top ends of hurricane protection panels and with an interior inwardly projecting arm to interface with the building structure. The bracket includes several elements which together form a space between the window and where the corrugated panels are inserted into the downwardly facing channel. On the inside of the bracket is a recess for placement of a flange window element such as already exists with conventional flange windows.
[0051] FIG. 11 is an exploded perspective view of a second sill bracket with a recessed bolt head track and a horizontal inwardly projecting arm to interface with the building structure. Disposed inwardly from the bolt head track is a vertical window element receiving slot for the insertion of a window element such as already exists with conventional flange windows. A bolt such as used in the track and accompanying wingnut are illustrated in proximity to and alignment with the track.
[0052] FIG. 12 is an exploded view of the brackets of FIGS. 10 and 11 with a conventional flange window and with a hurricane shutter panel in proximity to its installation position and with a typical bolt and wingnut used to secure the panel upon installation to the sill bracket.
[0053] FIG. 13 is an assembly drawing showing the elements of FIG. 12 completely assembled in a masonry building aperture.
[0054] FIG. 14 is an exploded perspective view of an alternative embodiment sill bracket for use with a sliding or roller window, but it lacks the recessed bolt head track of the first and second sill brackets. It includes a horizontal flat track at its top to interface with the frame of the window, from the outside edge of which depends downwardly a vertical member. The vertical member is perforated by one of a plurality of bolts pointing horizontally outward threaded through the vertical member. These receive wingnuts, one of which is shown in axial proximity to the bolt. The nuts and bolts attach isosceles trapezoidal panels to the third sill bracket. At the lower edge of the vertical member is an outwardly facing channel in which can be disposed the heads of screws for attachment of the third sill bracket to the building structure. At the center of the channel web is a longitudinal score mark to center the point of the screws in the channel. Adjacent to the lower flange of the channel and at right angles thereto is a base member vertical wall containing a stucco ground ridge. At the lower edge of the base member vertical wall and at right angles thereto is horizontal base member bottom, which terminates on its inward edge with an upwardly directed lip.
[0055] FIG. 15 an exploded perspective view of an alternative embodiment of a sill bracket with a horizontal groove having striated horizontal side walls to receive and retain the threads of machine screws that have a diameter equal to the width of the groove. Beneath the groove and at right angles to it is a vertical wall, under which is a channel and base member identical to that described for FIG. 14 . A sample machine screw is shown in proximity to the groove into which it is threaded.
[0056] FIG. 16 is an exploded perspective view of an alternative embodiment sill bracket with a recessed bolt head track. Disposed inwardly from the track is a vertical upwardly projecting arm to interface with the building structure. A sample bolt such as used in the track and axially aligned wingnut are shown in proximity to the track.
[0057] FIG. 17 is a perspective view of an alternative embodiment header bracket with a downwardly facing channel providing a location for the placement of the top ends of hurricane protection panels and with inwardly projecting ledges to act as a spacer providing separation from a window.
[0058] FIG. 18 is a perspective view of an alternative embodiment header bracket with a downwardly facing channel providing a location for the placement of the top ends of hurricane protection panels and with inwardly projecting and with an interior downwardly facing vertical window element receiving slot for the insertion of a window element such as already exists with conventional windows.
[0059] FIG. 19 is a perspective view of an alternative embodiment header bracket with a downwardly facing channel providing a location for the placement of the top ends of hurricane protection panels. The bracket includes a spacer to form a space between the window and where the corrugated panels are inserted into the downwardly facing channel. On the inside of the spacer is a window element groove for the insertion of a window element such as already exists with conventional windows.
[0060] FIG. 20 is an exploded perspective view of an alternative embodiment sill bracket with a recessed bolt head track. Disposed above and inwardly from the track is a horizontal inwardly projecting arm with vertically projecting grips for the attachment of various architectural features, and which also serves as a spacer to form a space between the window and where the corrugated panels are attached to the sill bracket. Below the face of the recessed bolt head track is a base member vertical wall containing a stucco ground ridge. At the lower edge of the base member vertical wall and at right angles thereto is horizontal base member bottom, which terminates on its inward edge with an upwardly directed lip. A sample bolt such as used in the track and axially aligned wingnut are shown in proximity to the track.
[0061] FIG. 21 is an exploded perspective view of an alternative embodiment sill bracket with a recessed bolt head track. Disposed above and inwardly from the track is a horizontal inwardly projecting arm which serves as a spacer to form a space between the window and where the corrugated panels are attached to the sill bracket. At the inside edge of the inwardly projecting arm is a vertical window element receiving slot for the insertion of a window element such as already exists with conventional windows. Beneath the face of the recessed bolt head track and co-planar therewith depends downwardly a vertical member. At the lower edge of the vertical member is an outwardly facing channel in which can be disposed the heads of screws for attachment of the present sill bracket to the building structure. At the center of the channel web is a longitudinal score mark to center the point of the screws in the channel. Adjacent to the lower flange of the channel and at right angles thereto is a base member vertical wall containing a stucco ground ridge. At the lower edge of the base member vertical wall and at right angles thereto is horizontal base member bottom, which terminates on its inward edge with an upwardly directed lip. A sample bolt such as used in the track and axially aligned wingnut are shown in proximity to the track.
[0062] FIG. 22 is an exploded perspective view of an alternative embodiment sill bracket with a recessed bolt head track. Disposed directly behind and inwardly from the track body is a vertical window element receiving slot for the insertion of a window element such as already exists with conventional windows. Beneath the face of the recessed bolt head track and co-planar therewith depends downwardly an abbreviated vertical member. At the lower edge of the vertical member is an outwardly facing channel in which can be disposed the heads of screws for attachment of the present sill bracket to the building structure. At the center of the channel web is a longitudinal score mark to center the point of the screws in the channel. Adjacent to the lower flange of the channel and at right angles thereto is a base member vertical wall containing a stucco ground ridge. At the lower edge of the base member vertical wall and at right angles thereto is horizontal base member bottom, which terminates on its inward edge with an upwardly directed lip. A sample bolt such as used in the track and axially aligned wingnut are shown in proximity to the track.
[0063] FIG. 23 is a perspective view of an alternative embodiment of a vertical window element receiving slot for the insertion of a window element such as already exists with conventional windows, but with striations on the vertical interior walls of the slot to receive and retain threads.
[0064] FIG. 24 is a perspective view of an alternative embodiment of a vertical window element receiving slot for the insertion of a window element such as already exists with conventional windows, but with an interior offset for providing better gripping.
[0065] FIG. 25 is a perspective view of an alternative embodiment of a vertical window element receiving slot for the insertion of a window element such as already exists with conventional windows, but with an interior channel for providing better gripping.
[0066] FIG. 26 an exploded cross-section view of a masonry window opening using a header bracket from FIG. 18 with a downwardly facing channel providing a location for the placement of the top ends of hurricane protection panels and using a lower sill bracket from FIG. 21 for receiving the head of a threaded bolt for the attachment of bottom ends of the hurricane protection panels with wingnut bolts. The panels are shown to the right of the building aperture with phantom lines illustrating the order of assembly.
[0067] FIG. 27 is a broken exploded cross section view of the lower end of a masonry building aperture using a sill bracket, bolt and wingnut for securing a hurricane protection panels (not shown). Seen is an interior projecting arm providing a spacer dividing the surface of the window from the location where the hurricane protection panels are attached to the bolts and wingnuts shown in exploded proximity to the recessed track.
[0068] FIG. 28 is a broken exploded cross section view of the lower end of a masonry building aperture using a sill bracket, bolt and wingnut from FIG. 21 for securing a hurricane protection panels (not shown). Included is the horizontal inwardly projecting arm which serves as a spacer to form a space between the window and where the corrugated panels are attached to the sill bracket. At the inside edge of the inwardly projecting arm is a vertical window element receiving slot in which has been inserted the window element. Bolts and wingnuts are shown in exploded proximity to the recessed track.
[0069] FIG. 29 is an exploded perspective view of a window using threaded studs penetrating the upper and lower portions of the fin or flange portion of the window providing a means for attaching a hurricane protection panels using a wingnut. Hurricane protection panels are shown in a vertical position, but it is understood that they may also be installed horizontally.
[0070] FIG. 30 is an exploded broken cross section view of a masonry building aperture header portion supporting the upper portion of a window with extending threaded studs for the mounting of the upper portion of hurricane protection panels attached by wingnuts as illustrated in exploded axially oriented configuration.
[0071] FIG. 31 is an exploded broken cross section view of a masonry building aperture header portion supporting the upper portion of a window, the building shown in phantom, with an angle iron having extending threaded studs through the angle iron and through the fin or flange of a window's edge for the mounting of the tops of hurricane protection panels attached by wingnuts.
[0072] FIG. 32 is an exploded broken cross section view of a masonry building aperture header portion supporting the upper portion of a window, the building shown in phantom, with an inverted U-shaped channel with an extending threaded stud through the U-shaped channel and through the fin or flange of a window edge for the mounting of the tops of hurricane protection panels attached by wingnuts.
[0073] FIG. 33 is a perspective view of a building having four windows, one hinged door and one sliding glass door. Four windows are shown installed with brackets and hurricane protection panels on the exterior of the windows. One sliding glass door is shown installed with vertical brackets and horizontal hurricane protection panels on the exterior of the sliding glass door. One hinged door is shown with upper and lower rows of threaded studs that offer a means for attaching the upper and lower portion of hurricane protection panels to a hinged door. This allows ingress and egress from the fully protected structure.
[0074] FIG. 34 is an exploded perspective view of the hinged door of FIG. 33 with the upper and lower rows of threaded studs that offer the means for attaching the upper and lower portion of hurricane protection panels to a hinged door to allow ingress and egress from the structure. The hurricane protective panels are shown to the right of the door.
[0075] FIG. 35 is an exploded perspective view of an alternative embodiment of the door of FIGS. 33 and 34 with upper and lower slide bolt recessed tracks (either flush or recessed) for holding the heads of bolts are used to attach upper and lower portions of hurricane protection panels to the door. Again, the hurricane protection panels are shown to the right of the door.
[0076] FIG. 36 is an exploded perspective view of a cross-section of the lower portion of a door with a slide bolt track channel for holding the head a bolt which provides a means for attaching the lower portion of hurricane protection panels to a door. When inverted, the same structure operated to attach the top portions of the panels to the top of the door.
[0077] FIG. 37 is an exploded cross-section view of a particle wood door in proximity to a pair of top/bottom J-brackets that add recessed bolt head track bodies containing recessed bolt head tracks to the top and bottom of a door to provide for mounting hurricane protection panels on the outside of the door without restricting egress or ingress through the door.
[0078] FIG. 38 is an assembly drawing showing the elements of FIG. 37 completely assembled in the aperture of a masonry building.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0079] 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.
[0080] 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.
[0081] FIG. 1 is a perspective view of a building 10 under construction having six building apertures, five windows 12 , 14 , 16 , 18 , and 20 , and one hinged door 22 . Two windows 16 and 18 are ready for installation with the header 24 and sill 26 brackets in place on the windows. Two windows 12 and 14 are shown installed with the header 24 and sill 26 brackets in place. One window is shown installed with hurricane shutter panels 28 in place to protect the building aperture.
[0082] FIG. 2 is an exploded perspective view of header 24 and sill 26 brackets above and below a typical window 30 with partial paneling 32 to the right side of the window. As shown by the phantom lines, the tops of panels 32 are first inserted into the header bracket 24 , then the panel bottoms, which are perforated 34 to receive threaded portions of bolts 36 are bolted to sill bracket 26 with wingnuts 38 .
[0083] FIG. 3 is a perspective view of a building 40 having six building apertures, four windows 42 , 44 , 46 , and 48 , one hinged door 50 and one sliding glass door 52 , all of which are covered with the inventive hurricane shutter apparatus. All the building apertures are protected by the preferred embodiment of a header 24 and a sill 26 bracket equipped with vertically disposed isosceles trapezoidal corrugated panels. The sliding glass door 52 is protected with alternative embodiment vertical brackets 54 with horizontal hurricane protection storm panels 56 . The vertical brackets 54 are similar to two sill brackets which have bolts to hold the horizontal panels 56 in place as better seen in FIG. 4 . The hinged door 50 uses an alternative embodiment exterior wall mounted header 24 and sill 26 supporting the isosceles trapezoidal corrugated panels 32 .
[0084] FIG. 4 is an exploded perspective view of a typical sliding glass door 58 with vertical brackets to be attached to the sliding glass door jambs 60 , with partial paneling 56 beneath the sliding glass door 58 . As shown by the phantom lines, the sides of panels 56 which are perforated 62 to receive threaded portions of bolts 64 are bolted to vertical brackets 54 with wingnuts 66 .
[0085] FIG. 5 is a perspective view of a first header bracket 112 comprised of a downwardly facing channel 114 having a channel web 116 , inner channel flange 118 and outer channel flange 120 . The lower edge of the outer channel flange includes a flare 122 . The channel web 116 is co-planar with a horizontal inwardly projecting arm 124 . Co-planar with the inwardly projecting arm 124 inside of the inner channel flange 118 is disposed a window element web 126 . That terminates with a downwardly depending window element flange 128 . The window element flange outer surface 129 is a contact point for a first window element known as a window flange as will be seen in FIG. 8 . The window element web 126 doubles as a spacer between the window and where the corrugated panels are inserted into the downwardly facing channel 114 . On the inside of the window element flange 128 and co-planar with the horizontal inwardly projecting arm 124 is a window depth spanner 130 . The window depth spanner 130 forms a space between the first window element and a second window element described below. At the inside edge of the window depth spanner 130 and disposed at right angles thereto is a vertical arm 134 . Finally, the vertical arm 134 is at right angles to a window element ridge 136 inside the top edge 138 of the vertical arm 134 . This provides for a window element recess 140 for insertion of the second window element, a window fin such as already exists with conventional fin windows as will be seen in FIGS. 7 and 8 .
[0086] FIG. 6 is a perspective view of a first sill bracket 141 comprised of a recessed bolt head track body 142 containing a recessed bolt head track 144 with a vertical track aperture 146 , vertical track upper face 148 , and vertical track lower face 150 . At right angles to the top of the track upper face 148 is a horizontal track body top 152 . It serves as a resting point for a first window element, the window flange, as will be seen in FIG. 8 . The horizontal track body top 152 also doubles as a spacer between the window and where the corrugated panels are bolted to the recessed bolt head track body 142 . At the inside edge of the track body top 152 and at right angles thereto is a vertical window depth spanner wall 154 . At the top edge of the vertical window depth spanner wall 154 and at right angles thereto is a horizontal window depth spanner 156 . At the inside edge 158 of the window depth spanner 156 is a vertical downwardly projecting arm 160 . At the bottom of the downwardly projecting arm 160 is an inwardly oriented window element ridge 162 , which creates a window element recess 164 between the downwardly projecting arm 160 and the building structure for the insertion of a second window element, a window fin, such as already exists with conventional fin windows.
[0087] FIG. 7 is an exploded view of the header bracket 112 of FIG. 5 and sill bracket 141 of FIG. 6 with a conventional fin window 520 and with a hurricane shutter panel 522 in proximity to its installation position and with a typical bolt 524 and wingnut 526 used to secure the panel upon installation to the sill bracket 141 . Fin window 520 includes a first window feature, window flanges 528 and 530 , and second window feature, window fins 532 and 534 .
[0088] FIG. 8 is an assembly drawing showing the elements of FIG. 37 completely assembled on a wood frame building 536 . Header bracket 112 is shown assembled with fin window 520 to wood frame building 536 using wood screw 538 . Wood screw 538 passes through vertical arm 134 of header bracket 112 first, then through window fin 532 before reaching the wood of building 536 . Note that window element ridge 136 creates a window element recess 140 for window fin 532 . Also note that window element flange 128 provides a contact point for window flange 528 . Further note that window element web 126 provides a spacer 540 between window 520 and where corrugated panels 522 are inserted into downwardly facing channel 114 . Finally note that window depth spanner 130 forms a space between first window element, window flange 528 , and second window element, window fin 532 . All of these spacing considerations make header bracket 112 completely compatible with conventional fin window 520 and show that the bracket 112 can be readily assembled with conventional fin window 520 when the latter is first placed in a wood frame building aperture at the time of construction.
[0089] The same is true for sill bracket 141 . Wood screw 538 passes first through vertical downwardly projecting arm 160 of sill bracket 141 and then through window fin 534 before reaching wood frame building 536 . Also window element ridge 162 creates window element recess 164 to accommodate window fin 534 . Also note that window flange 530 rests on horizontal track body top 152 and that horizontal track body top 152 also doubles as a spacer 540 between the window 520 and the corrugated panels 522 bolted to the recessed bolt head track body 142 . Note that horizontal window depth spanner 156 establishes the proper distance between window flange 530 and window fin 534 . So the sill bracket 141 meshes perfectly with conventional fin window 520 . Hurricane shutter panels 522 are firmly attached to sill bracket 114 using bolts 524 and wingnuts 526 .
[0090] FIG. 9 is an exploded bottom view of a sill bracket 542 and hurricane protection storm panels 522 in proximity thereto. A plurality of bolts 524 are slidingly installed in a track of bottom sill 542 as seen in FIG. 8 . The fact that they can slide laterally is illustrated by up and down arrows intercepting the threaded portion of each bolt 524 . Hurricane panels 522 , described early in this application as adjustable, lightweight isosceles trapezoidal corrugated panels, are attached to bolts 524 using wingnuts 522 shown in exploded proximal alignment to each other. Each panel 522 includes several conventionally sized isosceles trapezoidal corrugations 544 , 546 , 548 , and 550 followed by a wider than usual isosceles trapezoidal corrugation 552 . Overlapping the wide corrugation 552 is a conventionally sized corrugation 544 ′. As FIG. 9 shows, this means that panels can be adjusted laterally with respect to each other because the conventionally sized corrugation 544 can be slid one way or the other within the wide corrugation 552 .
[0091] FIG. 9A is a broken back elevation view of the bottom edge of a single hurricane protection storm panel 522 . Each of the alternating corrugations that come in contact with sill bracket 542 , such as corrugations 544 and 548 , include perforations 554 and 556 to accommodate the threaded portions of bolts 524 . But for wide corrugation 552 there is instead provided a slot 558 to accommodate the adjustment function with regard to the adjoining panel having a first corrugation 544 ′. This adjustment feature is obviously to accommodate different building aperture widths.
[0092] FIG. 10 is a perspective view of a second header bracket 68 comprised of a downwardly facing channel 70 having a channel web 72 , inner channel flange 74 and outer channel flange 76 . The lower edge of the outer channel flange includes a flare 78 . The channel web 72 is co-planar with a horizontal inwardly projecting arm 80 to interface with the building structure. On the inside of the inner channel flange 74 and part way down the inner channel flange 74 is a horizontal spacer web 82 . At the inside of the spacer web is a downwardly depending window element wall 84 . Inner channel flange 74 , spacer web 82 and downwardly depending window element wall 84 together form a space between the window and where the corrugated panels are inserted into the downwardly facing channel 70 . Co-planar with the spacer web 82 and inside of the window element wall 84 is a window element ridge 86 . The window element ridge creates a window element recess 88 between the building and the window element wall 84 for the insertion of a window element, a window flange, such as already exists with conventional flange windows.
[0093] FIG. 11 is an exploded perspective view of a second sill bracket 89 comprised of a recessed bolt head track body 90 containing a recessed bolt head track 92 with a track aperture 94 , track upper face 96 , and track lower face 98 . Co-planar with the track lower face 98 is a horizontal inwardly projecting arm 100 to interface with the building structure. Disposed inwardly from the bolt head track 92 is a vertical window element receiving slot 102 for the insertion of a window element, a window flange, such as already exists with conventional flange windows. The slot 102 is formed between the recessed bolt head track body 90 and a parallel vertical slot wall 104 . Recessed bolt head track body top 105 is of a width sufficient to provide a spacer between the window and where the corrugated panels are bolted to the recessed bolt head track body 90 . Co-planar with the slot wall 104 and depending vertically downwardly from beneath the horizontal plane of the inwardly projecting arm 100 is the downwardly projecting arm 106 . At the lower end of downwardly projecting arm 106 is base member 108 , on which is disposed stucco ground ridge 110 .
[0094] FIG. 12 is an exploded view of the header bracket 68 of FIG. 20 and the sill bracket 89 of FIG. 21 with a conventional flange window 560 and with a hurricane shutter panel 522 in proximity to its installation position and with a typical bolt 524 and wingnut 526 used to secure the panel upon installation to the sill bracket 89 . Flange window 560 includes window features, termed window flanges 562 and 564 .
[0095] FIG. 13 is an assembly drawing showing the elements of FIG. 40 completely assembled in a masonry building 566 . Conventional flange window 560 is shown installed in the masonry building 566 aperture between portions of wood buck 568 and 570 . The opening seen between masonry 566 and wood buck 570 is for shimming and caulking (not shown). The header bracket 68 is shown attached to masonry 566 through its horizontal inwardly projecting arm 80 using threaded masonry anchor 572 which passes first through wood buck 568 and then horizontal inwardly projecting arm 80 . Sill bracket 89 is shown attached to masonry building 566 indirectly. First, threaded masonry anchor 574 secures wood buck 570 to masonry building 566 . Second, sill bracket 89 is attached to wood buck 570 using wood screw 578 which passes through downwardly projecting arm 106 of sill bracket 89 . Flange window 560 is held in position at its top by the retention of window flange 562 by a window element recess 88 formed by window element ridge 86 . Conventional flange window 560 is held in position at its bottom by window flange 564 being retained in vertical window element receiving slot 102 in sill bracket 89 . Spacer web 82 in header bracket 68 provides a space 576 between flange window 560 and where corrugated panels 522 are placed in downwardly facing channel 70 in header bracket 68 . Similarly, recessed bolt head track body top 105 provides a space 576 between flange window 560 and where corrugated panels 522 are bolted to recessed bolt head track body 90 .
[0096] FIG. 14 is an exploded perspective view of an alternative embodiment sill bracket 166 for use with a sliding or roller window, but it lacks the recessed bolt head track of the first and second sill brackets. It includes a horizontal flat track 168 at its top to interface with the frame of the window, from the outside edge of which depends downwardly a vertical member 170 . The vertical member 170 is perforated by one of a plurality of bolts 172 pointing horizontally outward threaded through the vertical member 170 . These receive wingnuts 174 , one of which is shown in axial proximity to the bolt 172 . The nuts 174 and bolts 172 attach isosceles trapezoidal panels to the third sill bracket 166 . At the lower edge of the vertical member 170 is an outwardly facing channel 176 in which can be disposed the heads of screws for attachment of the third sill bracket 166 to the building structure. At the center of the channel web is a longitudinal score mark 178 to center the point of the screws in the channel 176 . Adjacent to the lower flange 180 of the channel 176 and at right angles thereto is a base member vertical wall 182 containing a stucco ground ridge 184 . At the lower edge of the base member vertical wall 182 and at right angles thereto is horizontal base member bottom 186 , which terminates on its inward edge with an upwardly directed lip 188 .
[0097] FIG. 15 is an exploded perspective view of an alternative embodiment of a sill bracket 190 with a horizontal groove 192 having striated horizontal side walls 194 to receive and retain the threads of machine screws that have a diameter equal to the width of the groove 192 . Inward and behind groove 192 is vertical window element receiving slot 195 for the insertion of a window element such as already exists with conventional windows. Beneath the groove 192 and at right angles to it is an abbreviated vertical wall 196 , under which is a horizontal channel 198 and base member 200 identical to that described for FIG. 14 . At the center of the channel web 201 of the channel 198 is longitudinal score mark 202 , which is used to center the point of screw (not shown) that attaches the sill bracket to the building structure. The base member 200 includes a stucco ground ridge 204 and lip 206 . A sample machine screw 208 is shown in proximity to the groove 192 into which it is threaded.
[0098] FIG. 16 is an exploded perspective view of an alternative embodiment sill bracket 210 with a recessed bolt head track 212 . Disposed inwardly from the track is a vertical upwardly projecting arm 214 to interface with the building structure. A sample bolt 172 such as used in the track 212 and axially aligned wingnut 174 are shown in proximity to the track.
[0099] FIG. 17 is a perspective view of an alternative embodiment header bracket 216 with a downwardly facing channel 218 providing a location for the placement of the top ends of hurricane protection panels. The channel is comprised of a channel web 220 , inner channel flange 222 , and outer channel flange 224 . The outer channel flange includes a flare 226 . On the inner channel flange 222 is inwardly projecting ledges 228 to act as a spacer providing separation from a window.
[0100] FIG. 18 is a perspective view of an alternative embodiment header bracket 230 with a downwardly facing channel 232 providing a location for the placement of the top ends of hurricane protection panels. The channel 232 is comprised of a channel web 234 , inner channel flange 236 , and outer channel flange 238 . The outer channel flange includes a flare 240 . On the inner channel flange 236 is an interior downwardly facing vertical window element receiving slot 242 for the insertion of a window element such as already exists with conventional windows.
[0101] FIG. 19 is a perspective view of an alternative embodiment header bracket 244 with a downwardly facing channel 246 providing a location for the placement of the top ends of hurricane protection panels. The channel 246 is comprised of a channel web 248 , inner channel flange 250 , and outer channel flange 252 . The outer channel flange includes a flare 254 . Co-planar with the channel web 248 is an inwardly projecting arm 256 which acts as an inward spacer to form a space between the window and where the corrugated panels are inserted into the downwardly facing channel 246 . On the inside edge of the inwardly projecting arm 256 is a downwardly facing window element groove 258 for the insertion of a window element such as already exists with conventional windows.
[0102] FIG. 20 is an exploded perspective view of an alternative embodiment sill bracket 260 with a recessed bolt head track 262 . Disposed above and inwardly from the track is a horizontal inwardly projecting arm 264 with vertically projecting grips 266 , 268 for the attachment of various architectural features, and which also serves as a spacer to form a space between the window and where the corrugated panels are attached to the sill bracket 260 . Below the face of the recessed bolt head track 262 is a base member vertical wall 270 containing a stucco ground ridge 272 . At the lower edge of the base member vertical wall 270 and at right angles thereto is horizontal base member bottom 274 , which terminates on its inward edge with an upwardly directed lip 276 . A sample bolt 278 such as used in the track 262 and axially aligned wingnut 280 are shown in proximity to the track 262 .
[0103] FIG. 21 is an exploded perspective view of an alternative embodiment sill bracket 282 with a recessed bolt head track 284 . Disposed above and inwardly from the track 284 is a horizontal inwardly projecting arm 286 which serves as a spacer to form a space between the window and where the corrugated panels are attached to the sill bracket 282 . At the inside edge of the inwardly projecting arm 286 is a vertical window element receiving slot 288 for the insertion of a window element such as already exists with conventional windows. Beneath the face 289 of the recessed bolt head track 284 and co-planar therewith depends downwardly an abbreviated vertical wall member 290 . At the lower edge of the abbreviated vertical wall member 290 is an outwardly facing channel 292 in which can be disposed the heads of screws (not shown) for attachment of the present sill bracket 282 to the building structure. At the center of the channel web 294 is a longitudinal score mark 296 to center the point of the screws (not shown) in the channel 292 . Adjacent to the lower flange 298 of the channel 292 and at right angles thereto is a base member vertical wall 300 containing a stucco ground ridge 302 . At the lower edge of the base member vertical wall 300 and at right angles thereto is horizontal base member bottom 304 , which terminates on its inward edge with an upwardly directed lip 306 . A sample bolt 278 such as used in the track 284 and an axially aligned wingnut 280 are shown in proximity to the track 284 .
[0104] FIG. 22 is an exploded perspective view of an alternative embodiment sill bracket 308 with a recessed bolt head track 310 . Disposed directly behind and inwardly from the track body 312 is a vertical window element receiving slot 314 for the insertion of a window element such as already exists with conventional windows. Beneath the face 316 of the recessed bolt head track 310 and co-planar therewith depends downwardly an abbreviated vertical wall member 318 . At the lower edge of the abbreviated vertical member 318 is an outwardly facing channel 320 in which can be disposed the heads of screws (not shown) for attachment of the present sill bracket 308 to the building structure. At the center of the channel web 322 is a longitudinal score mark 324 to center the points of the screws (not shown) in the channel 320 . Adjacent to the lower flange 326 of the channel 320 and at right angles thereto is a base member vertical wall 328 containing a stucco ground ridge 330 . At the lower edge of the base member vertical wall 328 and at right angles thereto is horizontal base member bottom 332 , which terminates on its inward edge with an upwardly directed lip 334 . A sample bolt 278 such as used in the track 310 and an axially aligned wingnut 280 are shown in proximity to the track 310 .
[0105] FIG. 23 is a perspective view of an alternative embodiment of a vertical window element receiving slot 336 for the insertion of a window element such as already exists with conventional windows, but with striations 338 on the vertical interior walls 340 of the slot to receive and retain threads.
[0106] FIG. 24 is a perspective view of an alternative embodiment of a vertical window element receiving slot 342 for the insertion of a window element such as already exists with conventional windows, but with an interior offset 344 for providing better gripping.
[0107] FIG. 25 is a perspective view of an alternative embodiment of a vertical window element receiving slot 346 for the insertion of a window element such as already exists with conventional windows, but with an interior wedge 348 for providing better gripping.
[0108] FIG. 26 an exploded broken cross section view of a masonry window opening 350 using a header bracket 352 from FIG. 16 with a downwardly facing channel 354 providing a location for the placement of the top ends of hurricane protection panels 356 and using a lower sill bracket 358 from FIG. 23 for receiving the head 360 of a threaded bolt 362 for the attachment of bottom ends of the hurricane protection panels 356 with wingnuts 364 . The panels 356 are shown to the right of the building aperture 350 with phantom lines 366 first and 368 second illustrating the order of assembly. FIG. 26 further shows the masonry building in broken cross section 370 and 372 with rebars 374 reinforcing the masonry. A window 376 is shown in the window opening 350 , with the upper portion of the window 376 shown supported by wood buck 378 .
[0109] FIG. 27 is a broken exploded cross section view of the lower end of a masonry building aperture 380 using a sill bracket 382 , bolt 362 and wingnut 364 for securing hurricane protection panels (not shown). Seen is an inwardly projecting arm 384 providing a spacer dividing the surface of the window 386 from the location where the hurricane protection panels are attached to the bolts 362 and wingnuts 364 shown in exploded proximity to the recessed track 388 . Window 386 is shown supported by wood buck 389 . Again the masonry 390 is in cross section with rebar 392 . The exterior of the masonry 390 is covered by stucco 394 , the limit of which in connection with sill bracket 382 is set by stucco ground ridge 396 .
[0110] FIG. 28 is a broken exploded cross section view of the lower end of a masonry building aperture 398 using a sill bracket 282 , bolt 278 and wingnut 280 from FIG. 23 for securing a hurricane protection panels (not shown). Included is the horizontal inwardly projecting arm 286 which serves as a spacer to form a space between the window 400 and where the corrugated panels (not shown) are attached to the sill bracket 282 . At the inside edge of the inwardly projecting arm 286 is a vertical window element receiving slot 288 in which has been inserted the window element 402 . Bolts 278 and wingnuts 280 are shown in exploded proximity to the recessed track 284 . Masonry 404 is shown faced with stucco 406 the limit of which in regard to the sill bracket 282 is set by stucco ground ridge 302 .
[0111] FIG. 29 is an exploded perspective view of a window 408 using threaded studs 410 and 412 penetrating the upper and lower portions of the fin or flange portion of the window providing a means for attaching a hurricane protection panels 414 using wingnut 416 and 418 . Hurricane protection panels 414 are shown in a vertical position, but it is understood that they may also be installed horizontally as shown in FIGS. 3 and 4 .
[0112] FIG. 30 is an exploded broken cross section view of a masonry building aperture 420 header portion 422 supporting the upper portion of a window 424 with extending threaded studs 426 for the mounting of the tops of hurricane protection panels 428 attached by wingnuts 430 as illustrated in exploded axially oriented configuration.
[0113] FIG. 31 is an exploded broken cross section view of a masonry building aperture 432 header portion supporting the upper portion of a window 434 , the building shown in phantom 436 , with an angle iron 438 having extending threaded studs 440 through the angle iron 438 and through the fin or flange 440 of a window 434 edge for the mounting of the tops of hurricane protection panels 442 attached by wingnuts 444 .
[0114] FIG. 32 is an exploded broken cross section view of a masonry building aperture 446 header portion supporting the upper portion of a window 448 , the building shown in phantom 450 , with an inverted U-shaped channel 452 with an extending threaded studs 454 through the U-shaped channel 452 and through the fin or flange 456 of a window 448 edge for the mounting of the tops of hurricane protection panels 458 attached by wingnuts 460 .
[0115] FIG. 33 is a perspective view of a building 462 having four windows 464 , 466 , 468 , and 470 , one hinged door 472 and one sliding glass door 474 . The four windows are shown installed with brackets 476 and 478 and hurricane protection panels 480 on the exterior of the windows 464 , 466 , 468 , and 470 . One sliding glass door 474 is shown installed with vertical brackets 482 and horizontal hurricane protection panels 484 on the exterior of the sliding glass door 474 . One hinged door 472 is shown with upper 486 and lower 488 rows of threaded studs that offer a means for attaching the upper and lower portion of hurricane protection panels 490 to a hinged door 472 . This allows ingress and egress from the fully protected structure.
[0116] FIG. 34 is an enlarged exploded perspective view of the hinged door 472 of FIG. 33 with the upper 486 and lower 488 rows of threaded studs that offer the means for attaching the upper and lower portion of hurricane protection panels 490 to a hinged door 472 to allow ingress and egress from the structure. The hurricane protective panels 490 are shown to the right of the door.
[0117] FIG. 35 is an exploded perspective view of an improved embodiment of a hinged door 492 similar to that shown in FIGS. 33 and 34 , but with upper 494 and lower 496 slide bolt recessed tracks for holding the heads of bolts 498 that are used to attach upper and lower portions of hurricane protection panels 500 to the door 492 . This is done by passing the bolts 498 through perforations 502 in the hurricane protection panels 500 and applying wingnuts 504 to the bolts 498 . In FIG. 35 , the slide bolt recessed track bodies 506 are applied to the exterior of a conventional door 492 .
[0118] FIG. 36 is an exploded perspective view of a cross section of the lower portion 508 of a more improved door with a slide bolt track channel 510 that is recessed within the door for holding the head of a bolt 512 that provides the means for attaching the lower portion of hurricane protection panels 500 (as shown in FIG. 35 ) to a door using a wingnut 514 . When inverted, the same structure operated to attach the top portions of the panels 500 to the top of the door. Because the slide bolt track channel 510 is recessed within the door, access by the bolt 512 heads to the track 510 must be had through relief notch 516 .
[0119] FIG. 37 is an exploded cross section view of a pair of add on recessed bolt head track door J-brackets 580 with a pre-existing particle wood door 582 in proximity to hurricane protection shutter panels 522 . The J-brackets 580 add recessed bolt head track bodies 584 containing recessed bolt head tracks 586 to the top and bottom of the door 582 for retaining bolt heads 524 , to which are then applied the shutter panels 522 and wingnuts 526 .
[0120] Turning finally to FIG. 38 , an assembly drawing showing add on recessed bolt head track door J-brackets 580 applied respectively to the top and bottom of wood particle door 582 , to which has been applied hurricane protection shutters 522 using bolts 524 and wingnuts 526 . The door 582 with J-brackets 580 and panels 522 is installed in a masonry building 588 with wood buck 590 , conventional door sill 592 , and interior molding 594 held by threaded masonry anchors 596 . The top mates with conventional wood frame header 598 . The periphery of the door 582 is surrounded by resilient compressible weather stripping 600 . One significant advantage of these add on recessed bolt head track door J-brackets 580 is that they allow the application of hurricane protection shutter panels 522 to a pre-existing door with little or no modification thereto and without interfering with the door's ingress and egress functions when the shutters 522 are deployed for storm protection. Additionally, if the door contains any glazing, the glazing is covered and protected. Finally, the door is strengthened by the application of the J-brackets 580 whether or not the hurricane protection panels 522 are deployed thereon.
[0121] While the invention has been described, disclosed, illustrated and shown in various 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 claims here appended.
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Disclosed is storm shutter apparatus for protecting building apertures such as door and window openings from hurricanes, wind-blown debris, gales, rain, and vandals using very low cost, low profile extrusion brackets designed specifically for installation during original building construction in combination with a variety of conventional manufactured windows, hinged doors or sliding glass doors in conventional building structures, and the use of those brackets with very low cost adjustable, lightweight isosceles trapezoidal corrugated panels. The first objective is to render building apertures compliant with the International Building Code (“I.B.C.”) even though they are constructed with conventional fenestration products unmodified for I.B.C. compliance. Another objective is to accomplish the foregoing without the expense of separate labor costs for the installation of hurricane shutters and without the expense of purchasing fenestration products modified for I.B.C. compliance.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119 to European patent application EP 07117917.0, filed Oct. 4, 2008, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to an authentication method and system, and more particularly to a two factor authentication system based on the generation of a low cost code book. The number of interactions that an individual may carry out via an electronic interface is continually increasing. Automatic Teller Machines are now ubiquitous, and with the spread of the Internet, services such as online commerce, Internet banking, credit card and other bill payments, personalized websites including webmail sites, and even tax declaration are increasingly common. In virtually all cases it is necessary for a user to identify himself to the system at some stage, and furthermore to authenticate this identity. The usual means for carrying out this authentication is by submitting a PIN code, password or other piece of secret data, which is known by the service and the user alone. With the multiplication of such services, an individual is required to maintain and remember an increasingly large number of such pieces of secret information. Furthermore, as a general rule it is desirable that each such piece of information should be unique to the service in question, and that it should be as large and random as possible, to minimize the risk of the discovery of one secret prejudicing the security of multiple systems, and the probability of a third-party guessing the secret. Ideally each piece of secret information should be replaced frequently to maintain high security standards. It is also highly undesirable that a user should write down or otherwise record such secrets in an unprotected manner. A tension thus arises between the need for a user to remember a large number of large pieces of random data, and the propensity of most individuals to choose the simplest option, such as choosing a well known and easy to remember set of passwords and using them in a cyclic way for all their services. This behaviour enormously reduces the security of protected resources.
SUMMARY OF THE INVENTION
According to the present invention, a codebook, comprising a number of groups of symbols in a predetermined pattern, is issued to a user. The user is attributed or selects an extraction pattern representing an order of progression through the symbols in each group of symbols. When the user wishes to make an authentication action an authentication party which also has knowledge of the content of the codebook and the extraction pattern challenges the user to submit the symbols found at selected positions in the extraction pattern. The user applies the extraction pattern to the codebook and retrieves the symbols found at the selected positions, and submits these to the authenticating party. The authenticating party applies the same extraction pattern to the same codebook, and determines whether the results match those submitted by the user, and in a case where the two sets of symbols match, authenticates the user.
The method of the present invention may also be employed using an authenticating computer system and a codebook. The computer system can receive requests for authentication across a network, poll the requesting parties for data strings based upon extraction of information from requested reference sequences and extraction patterns from the codebook, and, if a comparison of the information received from the requesting party matches the expected result, the requesting party may be authenticated to access a program on the authenticating computer system or to access another computer across the network.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram view of a first embodiment of the present invention;
FIG. 2 is a flow diagram view of a second embodiment of the present invention;
FIG. 3 is a flow diagram view of a third embodiment of the present invention;
FIG. 4 is a view of an exemplary configuration of a reference sequence;
FIG. 5 is an illustration of a codebook on a physical support according to an embodiment;
FIG. 6 displays the application of the extraction of the present invention to a physical support of FIG. 5 ;
FIG. 7 illustrates an exemplary extraction pattern of the present invention;
FIG. 8 further illustrates use of an extraction pattern with the present invention;
FIG. 9 shows the physical support of FIG. 6 , with the symbols in the positions not requested obscured for the sake of clarity;
FIG. 10 is a screenshot of an interface for the activation step of the present invention; and
FIG. 11 is a block diagram of a computer system suitable for implementing the present invention.
DETAILED DESCRIPTION
Referring now to FIG. 1 , a flow chart of a first embodiment of the invention is shown and will be described. A user seeking authentication to access a secure network or other electronic service initiates authentication by using a device, such as a mobile telephone, PDA, personal computer, automated teller machine terminal, to poll an authenticating party. This may be done by the use of a conventional login, by entering a user name, or otherwise providing user information to the network in a convention low-security manner. The user then receives notification from the authenticating party identifying an extraction pattern position for a selected reference sequence from a codebook comprising a first predetermined number of different reference sequences, each of said reference sequences comprising a second predetermined number of symbols and a unique identifier 106 . Next, in response to said notification, the user references the code book to apply the extraction pattern to specific positions in sequence to extract a second predetermined number of symbols to said selected reference sequence so as to extract requested symbols at the extraction pattern position identified by said identifier 107 . The user then returns the extracted symbol or symbols are to the authenticating party 108 . The extracted request symbol or symbols are returned so that the authenticating party may apply the extraction pattern to each respective selected reference sequence to a matching local copy of the codebook so as to extract one or more authentication symbols 1081 , and the authentication symbols received by the authenticating party from the user are then compared to the corresponding request symbols 1082 . If, in each respective authentication symbol matches the corresponding request symbol 1083 , the authenticating party authenticates the user 1084 .
Referring now to FIG. 2 , a flow chart for an alternative embodiment of the invention is shown and will be described. More particularly, in addition to steps 106 to 108 as described in FIG. 1 and again incorporated within this embodiment, FIG. 2 further illustrates a prior step of defining a codebook 201 , and further defining extraction patterns 202 by referencing the codebook. Unlike other secure methods that require a time chip, a USB key or another electronic device, a codebook may consist of printed matter, such as a reference card. The codebook and the extraction pattern are provided to both an authenticating party and a requesting party 203 . The extraction pattern and the codebook may be defined at the user device, or at the authenticating party, or by collaboration between these two parties, or either or both may still further be provided by one or more third parties. Both the authenticating party and the user device must share knowledge of the extraction pattern and the codebook. The codebook may be randomly or pseudorandomly generated. The extraction pattern may be selected by the user for example from a standard set of possible patterns. The extraction pattern may alternatively be any arbitrary pattern as selected by the authenticating party or the user or randomly or pseudorandomly determined. An underlying assumption of the present authenticating method is that the codebook and the extraction pattern are known only to the two parties, and to no other party. Knowledge of either the codebook or the extraction pattern alone by a third party does not prejudice the security of the method however. It is therefore desirable to provide the codebook and the extraction pattern to the parties 203 via a secure method. The data may be sent as an encrypted electronic signal, or may be sent by some alternative parallel channel such as by conventional mail, facsimile message, telephone message, or other communication methods known in the art.
Referring now to FIG. 3 , a flow chart for a second alternative embodiment of the invention is shown and will be described. This embodiment incorporates the steps of the prior two embodiments described above, but includes additional intermediate steps. Namely, after the codebook 201 and extraction pattern 202 are defined and the codebook is provided to the authenticating and requesting parties 203 , the method of FIG. 3 comprises the further steps of the authenticating party selecting at least one of the plurality of reference sequences 304 , and then notifying the unique identifier thereof to the requesting party 305 . Thus from a codebook containing a plurality of reference sequences, a subset of the available reference sequences may be selected for any given authentication. The selected reference sequences may be chosen in a manner which is random, pseudorandom or otherwise unpredictable to external parties. The reference sequences for use in authentication may be preselected by the user or the authenticating party either for a particular authentication situation, or for all authentications. The reference sequences may be redefined as necessary. The steps of receiving notification 106 , applying the extraction pattern 107 , returning the extracted symbol 108 and verifying 1083 , along with all other steps, as initially described in the discussion of FIG. 1 , remain the same throughout all embodiments of the invention.
Reviewing FIG. 3 and the previous figures, the method of the present invention consists of the steps of defining a codebook 201 comprising a first predetermined number of different reference sequences, each of said reference sequences comprising a second predetermined number of symbols and a unique identifier. An extraction pattern 202 is identified, and the codebook is providing the codebook to a requesting party 203 . It is noted that the extraction pattern may be identified by the authenticating party, selected by the requesting party or otherwise created by collaboration between the authenticating party and the requesting party. It is further noted that the codebook may be provided 203 in physical or electronic form, and, if provided in electronic form, may be printed by the requesting party or stored in a memory for later retrieval and on-screen viewing on a computer, PDA, cell phone, or another electronic device including a screen as known in the art. Next, the authenticating party waits to receive a request from a requesting party for authentication to start the authentication sequence. The authenticating party responds to the authentication request by specifying at least one selected reference sequence 304 and notifying the requesting party of the unique identifier of the reference sequence 305 . It is noted that the reference sequence may be preselected prior to receiving a request from the requesting party and queued awaiting a request, or selected when a request is received. The requesting party receives the information identifying the reference sequence, and then acts upon the received information of the reference sequence 106 and unique identifier by applying the extraction pattern 107 , and returning the code extracted 108 . This reception and return of information can be done across a network using any network device, such as a computer, a telephone, a PDA or other electronic communications device, or the present invention could also be employed on a single computer. The authenticating party then compares the sequence of data returned from said requesting party based on the extracted symbols determined from said reference sequence using the extraction pattern position with an expected sequence based upon the previously determined reference sequence in the codebook 1082 , then, if the comparison of returned data matches the expected sequence 1083 , authenticates the requesting party 1084 . The authenticating party may be a remote authenticator, allowing the requesting party to access another site or program on the network, or may reside on the same computer as the program to which the requesting party seeks authentication.
Turning now to FIG. 4 , an exemplary configuration of a reference sequence is illustrated. In the current embodiment of the invention, the codebook is embodied as physical printed matter. This physical support may be, for example, a piece of sheet material, such as paper, card, plastic or similar material, upon which are printed the first plurality of reference sequences, each comprising the second plurality of symbols and a respective unique identifier. It will be understood that the unique identifier need not be explicitly provided, but may be implicitly provided in the form of the position of the reference sequence on the physical support, e.g. by means of the identifier “top left” and so on. One obvious special case is the situation where only one reference sequence is provided, where the identifier is simply, “the only reference sequence provided”. Other unique identifiers my take the form of the colour, shape or configuration of the reference sequence. As shown by the token illustrated, the reference sequence comprises a rectangle 401 containing nine identical smaller rectangles in a 3 by 3 matrix. The central one of these nine smaller rectangles 402 contains a symbol service as a unique identifier for the reference sequence in question. As shown here, the unique identifier is a number 1 . The remaining eight smaller rectangles 4011 , 4012 , 4013 , 4014 , 4015 , 4016 , 4017 and 4018 are arranged around the central rectangle 402 . Each of these peripheral rectangles contains an authentication symbol, which as shown consist in each case of a pair of alphanumeric characters. Naturally, any symbol or user identifiable characteristic may be used as an authentication symbol, for example, characters of any alphabet, pictograms or images, colours, patterns and so on. The limiting considerations are simply that the user must be able to distinguish one from another, and submit the same to the authenticating party. In some cases this may call for the use of an existing interface wherein alphanumeric or even purely numeric input is necessary.
FIG. 5 shows a codebook on a physical support according to an embodiment. As shown in FIG. 5 there is provided a physical support 500 bearing eight reference sequences 501 , 502 , 503 , 504 , 505 , 506 , 507 and 508 , having the unique identifiers 1 , 2 , 3 , 4 , 5 , 6 and 7 respectively. These eight reference sequences are each laid out is the same manner as that described with respect to FIG. 4 . It will be noted that the authentication symbols provided in each reference sequence are different from one sequence to the next, and that there is no discernable pattern in the authentication symbols.
FIG. 6 shows the application of the third embodiment to the physical support of FIG. 5 . In accordance with the third embodiment of the invention as described above, at step 305 one or more reference sequences are selected from the available plurality, and the selected reference sequences are notified to the user by means of the unique identifier of each selected reference sequence. In this example, the first, third, fourth and seventh reference sequences were selected for a particular authentication operation. Subsequently, the authenticating party notifies the user with the unique identifiers “ 1 ”, “ 3 ”, “ 4 ” and “ 7 ”, on the basis of the physical support shown in FIG. 5 . The user may then disregard the reference symbols 502 , 505 , 506 and 508 . Accordingly, as shown in FIG. 6 , only the remaining reference sequences 501 , 503 , 504 and 507 are retained. In some embodiments, this obscuring of the reference sequences not required for a particular authentication is only notional. In other embodiments, some or all reference sequences may be obscured by, for example, a foil or other removable layer, with only the sequences requested by the authenticating party being laid bare.
Turning now to FIG. 7 , an exemplary extraction pattern is shown. As described above, it is necessary to apply an extraction pattern to the selected reference sequence or sequences. FIG. 7 shows a reference sequence as a 3 by 3 matrix, although the authentication symbols are omitted for the same of clarity. An arrow 700 indicating a path through the eight peripheral smaller rectangles describes a spiraling path starting at the top left outer rectangle and proceeding clockwise about the center. This spiral represents the sequence in which one would count through the various symbols in order to arrive at a particular selected extraction pattern position. For example, if the third extraction pattern position was requested, the symbol retrieved would be that located in the top right hand rectangle. If the eighth extraction pattern position was requested, the symbol retrieved would be that located in the left hand column on the second row, and so on.
FIG. 8 shows the extension of the extraction pattern previously described extended to larger numbers. The extraction pattern position number may be greater than the number of symbols present. In such cases, the extraction pattern may be applied in a repetitive manner until the position number is attained. As previously described with respect to FIG. 7 , extraction pattern positions 1 to 8 are arrived at by a simple application of the extraction pattern to the matrix, as shown in the leftmost matrix 801 . When a ninth extraction pattern position is called for, the pattern simply starts again at the first position, and so on as shown in the central matrix 802 , similar to a modulo operation.
As described, the present invention implements a two-factor authentication mechanism, because it is based on something the user owns, namely the codebook, and something the user knows (the extraction pattern to decode authentication questions using the card). One skilled in the art will appreciate that a very wide range of extraction patterns may be envisioned. Even in the case of the simple matrix described in the forgoing embodiments a very large number of permutations are possible, including spirals or circles in either direction, zig-zags along horizontal or vertical lines, letters of the alphabet or other characters and myriads of other patterns. Different extraction patterns may be applied for different reference sequences. The number of positions defined in an extraction pattern before it starts repeating itself may not be equal to the number of positions in the reference sequence, so that each iteration starts from a different point. Still further, rather than simply repeating the pattern as previously described for position numbers greater than positions given, a different series of steps may be described for subsequent iterations. For example, while for positions 1 to 8 a clockwise circulation though the various positions is described, for positions 9 to 17 a reverse in direction may be called for as shown in element 803 . Again, any number of variations may conceived. The number of positions prior to a change in pattern need not be an integral multiple of the number of positions. The pattern may be entirely arbitrary, although, for ease of the use, it is preferable that the pattern should correspond to some easily memorable pattern such as a sequence of spirals or circles in either direction, zig-zags along horizontal or vertical lines, letters of the alphabet or other characters. With a simple reference sequence selection of 6 digits and a {8,8,2} codebook, that is, a codebook with 8 reference sequences, 8 authentication symbols per reference sequence and 2 characters per authentication symbol, it is possible to generate to 8^6=262, 144 different authentication questions and provide as many answers composed by 6*2=12 symbols.
Turning now to FIG. 9 , one can appreciate that by applying the given extraction pattern to selected reference sequences as described with respect to FIG. 6 , it is possible to extract a series of authentication symbols. Continuing the prior examples, and using a clockwise extraction pattern starting at the upper left corner illustrated in FIG. 7 , suppose that reference sequences 1 , 3 , 4 and 7 and the positions 1 , 2 , 7 and 5 have been requested. FIG. 9 shows the physical support of FIG. 6 , with the symbols in the positions not requested obscured for the sake of clarity. Thus as shown by applying the sequence of FIG. 7 to the reference sequence numbered 1 , and selecting the first position in the pattern, we select the symbol “SD” in the top left rectangle of the top left reference sequence. Next as shown by applying the sequence of FIG. 7 to the reference sequence numbered 4 , and selecting the second position in the pattern, we select the symbol “JP” in the top centre rectangle of the third reference sequence in the top row. Next as shown by applying the sequence of FIG. 7 to the reference sequence numbered 4 , and selecting the seventh position in the pattern, we select the symbol “V4” in the bottom left rectangle of the rightmost reference sequence in the top row. Finally as shown by applying the sequence of FIG. 7 to the reference sequence numbered 7 , and selecting the fifth position in the pattern, we select the symbol “T3” in the bottom right rectangle of the third reference sequence in the top row. When thus applying the selection process at the user site, the extracted symbols “SD,JP,V4,T3” can then be transmitted to the authenticating party. By applying the same process at the authenticating party, the same symbols can be derived, and compared to those received for the user, and in a case where the two sets of symbols are found to match, the authenticating party can authenticate the user, as described above. Positions 1 , 2 , 7 and 5 are derived from the secret key the user knows and that has been communicated to the authentication service at the time of card activation. User applies his key code according to a known (to the user and to the authentication system) mapping strategy. The key code is applied always in the same way, regardless of the reference sequences asked by the authentication system. For instance, if the key code is exactly 1275 and the mapping strategy is the clockwise spiral represented in FIG. 7 , when the system asks for reference sequences 2 , 3 , 5 , 8 from the card represented in FIG. 5 , the extracted symbols will be: L2-L5-D7-58; again, if the system asks for reference sequence 2 , 4 , 6 , 7 , the extracted symbols, using the same key code and mapping strategy, will be: L2-P1-12-T3.
In the present invention, the authenticating party may optionally be a central authentication service which provides authentication for a number of different services. The central authentication may define and distribute codebooks, and issue notifications. All communications may pass through service providers making use of this centralised authentication system. Such a centralized authentication service may act as a hub of user profile data; this allows service providers to just define which information is relevant for them, and it can be extracted from existing profiles, thereby minimizing data entry from the end user of multiple services. Service providers may also agree with the authenticating party about quality and strength of authentication (SLA), such as the minimum length of authentication answers, size and lifetime of codebooks, entropy of authentication answers, and other security parameters. Centralization of user profile data is also valuable for end users since they can immediately know the services to which they are subscribed, and may easily update profile information to all subscribed services or revoke or suspend one or all user subscriptions with just one click. The authenticating party may generate authentication questions with a limited lifetime, which are equivalent to one time passwords. In such cases if the delay between step 1 - 6 and step 1081 exceeds a predetermined delay, authentication may be automatically refused, and the process may optionally return to step 106 , with new reference sequences and extraction pattern positions being requested.
Turning now to FIG. 10 , an optional implementation of the present invention is illustrated and will be described. Initially, a user seeks access to a particular service provider, which may optionally forward the user to the authenticating party. The user is then able to register with the authenticating party providing basic profile information, and choosing a username and a temporary password. The authenticating party generates a codebook according to the SLA with the service provider and binds it to the service of the provider as requested by the user. A codebook is delivered to the user, using a method known in the art such as sending a download link to the user e-mail address for downloading and printing, or delivering a codebook via a physical courier. After receiving the codebook, the user must activate it, communicating to the authenticating party the preselected reference sequences and the extraction pattern he will use. The preselected reference sequences and/or the extraction pattern can be changed at any time during the codebook lifetime. For example, a conventional computer graphical user interface window such as a web browser 1000 , comprising a text box 1001 for the entry of the selected reference sequences, a button or similar interface feature 1002 to initiate the automatic selection of reference sequences and a set of “radio buttons” or the like associated with a set of predefined extraction patterns from which a user may select. Changing the extraction pattern is the easiest way to modify the authentication answer to a same authentication question; a user will always remember the same reference sequences and will just apply a different mapping strategy of the code on his/her card, thereby reading the card in a different manner. An authenticating party can use the same authentication mechanism offered to service providers; after a user activates a codebook, he can choose to use it also to logon to the authenticating party; no additional password is required: the user will just remember the reference sequences and own the appropriate extraction pattern. Given the extremely low cost and ease of generation of the physical support for the codebook, users may own multiple codebooks, one for each type of services; generally, this is not possible with other two-factor authentication systems currently known in the art, because almost all of them rely on hardware devices, which are much more expensive than a physical support such as a printed card as previously described.
FIG. 11 depicts a computer system suitable for implementing the present invention. Computer system 1100 may correspond to the user device described above and comprises a processor 1110 , a main memory 1120 , a mass storage interface 1130 , a display interface 1140 , and a network interface 1150 . These system components are interconnected through the use of a system bus 1101 . Mass storage interface 1130 is used to connect mass storage devices (Hard disk drive 1155 ) to computer system 1100 . One specific type of removable storage interface drive 1162 is a floppy disk drive which may store data to and read data from a floppy disk 1195 , but other types of computer readable storage medium may be employed, such as readable and optionally writable CD-ROM drive. There is similarly provided a user input interface 1144 which received user interactions from interface devices such as a mouse 1165 and a keyboard 1164 . There is still further provided a printer interface 1146 which may send and optionally receive signals to and from a printer 1166 . Main memory 1120 in accordance with the preferred embodiments contains data 1122 , an operating system 1124 . Computer system 1100 utilizes well known virtual addressing mechanisms that allow the programs of computer system 1100 to behave as if they only have access to a large, single storage entity instead of access to multiple, smaller storage entities such as main memory 1120 and HDD 1155 . Therefore, while data 1122 , operating system 1124 , are shown to reside in main memory 1120 , those skilled in the art will recognize that these items are not necessarily all completely contained in main memory 1120 at the same time. It should also be noted that the term “memory” is used herein to generically refer to the entire virtual memory of computer system 1100 . Data 1122 represents any data that serves as input to or output from any program in computer system 1100 . Operating system 1124 is a multitasking computer operating system; those skilled in the art will appreciate that the spirit and scope of the present invention is not limited to any one operating system. Processor 1110 may be constructed from one or more microprocessors and/or integrated circuits. Processor 1110 executes program instructions stored in main memory 1120 . Main memory 1120 stores programs and data that processor 1110 may access. When computer system 1100 starts up, processor 1110 initially executes the program instructions that make up operating system 1124 . Operating system 1124 is a sophisticated program that manages the resources of computer system 1100 . Some of these resources are processor 1110 , main memory 1120 , mass storage interface 1130 , display interface 1140 , network interface 1150 , and system bus 1101 . Although computer system 1100 is shown to contain only a single processor and a single system bus, those skilled in the art will appreciate that the present invention may be practiced using a computer system that has multiple processors and/or multiple buses. In addition, the interfaces that are used in the preferred embodiment each include separate, fully programmed microprocessors that are used to off-load compute-intensive processing from processor 1110 . However, those skilled in the art will appreciate that the present invention applies equally to computer systems that simply use I/O adapters to perform similar functions. Display interface 1140 is used to directly connect one or more displays 1160 to computer system 1100 . These displays 1160 , which may be non-intelligent (i.e., dumb) terminals or fully programmable workstations, are used to allow system administrators and users to communicate with computer system 1100 . Note, however, that while display interface 1140 is provided to support communication with one or more displays 1160 , computer system 1100 does not necessarily require a display 1165 , because all needed interaction with users and other processes may occur via network interface 1150 . Network interface 1150 is used to connect other computer systems and/or workstations (e.g., 1175 in FIG. 11 ) to computer system 1100 across a network 1170 . The present invention applies equally no matter how computer system 1100 may be connected to other computer systems and/or workstations, regardless of whether the network connection 1170 is made using present-day analogue and/or digital techniques or via some networking mechanism of the future. In addition, many different network protocols can be used to implement a network. These protocols are specialized computer programs that allow computers to communicate across network 1170 . TCP/IP (Transmission Control Protocol/Internet Protocol) is an example of a suitable network protocol, for example over an Ethernet network. As shown, the network 1170 connects the system 1100 to two further devices 1171 and 1172 , which may be other computer systems similar to that described above, or other network capable devices such as printers, routers etc. In the present example, network device 1172 is a local server, which is connected via a modem 1181 to a public network 1180 such as the World Wide Web. By means of this public network 1180 a connection to a remote device or system 1185 may be established. The role of the authenticating party as described above may be implemented by a local network computer 1170 , a local server 1172 or a remote system or device 1185 , depending on the implementation of the invention selected.
It is important to note that while the present invention has been and will continue to be described in the context of a fully functional computer system, those skilled in the art will appreciate that the present invention is capable of being distributed as a program product in a variety of forms, and that the present invention applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution. Examples of suitable signal bearing media include: recordable type media such as floppy disks and CD ROM 1195 , and transmission type media such as digital and analogue communications links. The invention can take the form of an entirely hardware embodiment, with recourse to suitably specified FPGAs, ASICs, CPLDs, dedicated integrated circuits and circuits formed of discrete components or any combination of all of these, an entirely software embodiment e.g. in the form of software running on conventional hardware as described above with regard to FIG. 11 , or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode and other forms of implementation known in the art. Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD. A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers. Network adapters may also be coupled to the system to enable the data processing system to communicate with other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.
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A codebook, comprising a number of groups of symbols in a predetermined pattern printed on a card or the like is issued to a user. The user is attributed or selects an extraction pattern representing an order of progression through the symbols in each group of symbols. When the user wishes to make an authentication action an authentication party challenges the user to submit the symbols found at selected positions in the extraction pattern. The user applies the extraction pattern to the codebook and retrieves the symbols found at the selected positions, and submits these to the authenticating party. The authenticating party applies the same extraction pattern to the same codebook, and determines whether the results match those submitted by the user, and in a case where the two sets of symbols match, authenticates the user.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/955,553 titled “Improved Bias Tee Designs with Extended Low Current Measurement and AC High Impedance Measurement Capability” filed Mar. 19, 2014, which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This disclosure relates to bias tees, and, more particularly to configurable bias tees that improve current processes for low current measurements and AC high impedance measurements.
[0004] 2. Description of Related Art
[0005] A bias tee is typically a passive, three-port electrical network that may act as a diplexer. In one mode of operation, one port of the bias tee network is connected to a very low frequency or direct current (DC) source and another port is connected to a high frequency or alternating current (AC) source. The bias tee combines the DC source signal and the AC source signal so that the third port of the network is simultaneously coupled to both the DC and AC signals. Bias tees are well-known electrical devices which are useful in many applications where it is necessary to inject DC power into an AC signal. Typical applications include powering photodiodes, lasers, or remote antenna amplifiers.
[0006] Bias tees are also typically bi-directional. Therefore, in another mode of operation, a combined AC and DC (“AC+DC”) signal is applied to the third port of the tee, and the bias tee network separates the AC and DC components of the signal so that the AC component of the signal can be measured at the AC port of the tee, and the DC component of the signal can be measured at the DC port of the tee. Examples of applications that use a bias tee in this mode include packaged device characterization and wafer probing. In these types of applications, connecting the combined AC+DC port of the tee to the output of the device under test allows a user to measure the DC characteristics of the device, and to measure the AC characteristics of the device, without having to re-configure the test setup between the DC and AC tests. In such applications, for certain types of devices, the bias tee carries very low DC current levels, as well as AC signals for high impedance measurements to the measurement instrument. Achieving good performance for both low current DC measurements and AC high impedance measurements presents special challenges to the designer of a bias tee.
[0007] The simplest bias tee designs employ a capacitor, a resistor, and three coaxial connectors. The coaxial connectors serve as a DC signal port, an AC signal port, and a combined AC+DC signal port for the tee. The capacitor is connected between the AC signal port and the AC+DC signal port. The resistor is connected between the DC signal port and the AC+DC signal port. The overall DC performance of this bias tee design is limited because the resistive element limits the current that can travel through the DC path of the tee.
[0008] Improved DC performance is achieved with a modified bias tee design in which the resistor in the DC path is replaced with an inductor. Although an ideal inductor would block the AC signal from passing back to the DC port, the AC performance of this design can be limited by the potential LC resonance effects. Also, since such a design uses coaxial connectors as the ports of the tee, its low current performance is limited due to the leakage current inherent in coaxial connectors.
[0009] To improve low current performance, triaxial connectors, rather than coaxial connectors, are used for the DC port and the AC+DC port. The single capacitor in the designs described above is replaced with two capacitors in series. One of the capacitors is “guarded” by the DC signal, thereby minimizing the leakage current through this capacitor. However, because this capacitor usually has relatively large capacitance, it will tend to generate current noise, thereby still hampering the low current performance of the bias tee.
[0010] Embodiments of the invention address these and other limitations of the prior art.
BRIEF SUMMARY OF THE INVENTION
[0011] A configurable bias tee includes an AC signal port, a DC signal port, and an AC+DC signal port. The bias tee has triaxial connectors as the DC signal port and the AC+DC signal port. A first electrical network coupled between the DC signal port and the AC+DC signal port provides a DC signal path through the tee. A second electrical network is coupled between the AC signal port and the AC+DC signal port. The second electrical network includes a first capacitor, a switch, and a second capacitor in series. The second capacitor is “guarded” by the guards of the triaxial DC and AC+DC signal ports. The switch is configured to provide an AC signal path through the tee when closed, and to disconnect the AC path when opened.
[0012] Methods of using a configurable bias tee with an AC signal path and a DC signal path include opening either the AC signal path or the DC signal path, and measuring a signal conveyed through the non-opened path at either, respectively, the DC signal port or the AC signal port.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] FIG. 1 is a schematic diagram of a conventional bias tee incorporating coaxial connectors, a capacitor, and a resistor.
[0014] FIG. 2 is a schematic diagram of a conventional bias tee incorporating coaxial connectors, a capacitor, and an inductor.
[0015] FIG. 3 is a schematic diagram of a conventional bias tee incorporating a coaxial connector, triaxial connectors, a capacitor, and an inductor.
[0016] FIG. 4 is a schematic diagram of a bias tee network incorporating a switch into the AC signal path, according to some embodiments of the invention.
[0017] FIG. 5 is a schematic diagram of a bias tee network incorporating switches into the AC signal path and the DC signal path, according to some embodiments of the invention.
[0018] FIG. 6 is a schematic diagram of a bias tee network incorporating switches into the AC signal path and the DC signal path, with isolated control circuitry for the switches, according to some embodiments of the invention.
[0019] FIG. 7 is a schematic diagram of a bias tee network incorporating switches into the AC signal path and the DC signal path, with control circuitry for the switches being driven by the AC signal, according to some embodiments of the invention.
[0020] FIG. 8 is a schematic diagram of a bias tee network incorporating a switch into the AC signal path, and diodes into the DC signal path, according to some embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] FIG. 1 shows a simple conventional bias tee network 100 including a coaxial connector 105 serving as an AC signal port, a coaxial connector 110 serving as a DC signal port, a coaxial connector 115 serving as a combined AC+DC signal port, a capacitor 120 coupled between the AC signal port 105 and the AC+DC signal port 115 , and a resistor 125 coupled between the DC signal port 110 and the AC+DC signal port 115 . The capacitor couples an AC signal to the AC+DC port, but generally blocks a DC signal from passing back to the AC port, thereby providing an AC signal path 104 through the bias tee. The resistor couples a DC signal to the AC+DC port, thereby providing a DC signal path 103 through the bias tee. As explained above, this type of bias tee allows for generally good AC coupling, but its DC performance is limited by the resistor in the DC signal path.
[0022] FIG. 2 shows a conventional bias tee network 200 that offers improved DC performance compared to the bias tee shown in FIG. 1 . The bias tee 200 is similar to the bias tee depicted in FIG. 1 except that the resistor in the DC signal path is replaced by an inductor 225 . This bias tee design has improved DC performance, because a full range of current can be delivered to an AC+DC signal port 215 , assuming the inductor 225 used is physically capable of handling the required current. But, the tradeoff for this improvement in DC performance is a reduction in AC performance due to LC resonance, depending on the selection of a capacitor 220 and the inductor 225 . Additionally, the bias tee 200 has limited low current performance due to the physical real-world non-ideal characteristics of the inductor 225 , as well as the leakage current inherent in a coaxial DC signal port 210 and the coaxial AC+DC signal port 215 .
[0023] Another type of conventional bias tee design, a bias tee network 300 depicted in FIG. 3 , improves the low current performance of the tee. The design of the bias tee network 300 is similar to the bias tee network depicted in FIG. 2 , except that in bias tee network 300 , the single capacitor in an AC signal path 304 is replaced with two capacitors in series—a capacitor 320 and a capacitor 330 . Like the bias tee network depicted in FIG. 2 , a coaxial connector 305 serves as the AC signal port. However, in the bias tee network 300 , the connector serving as the DC signal port is a triaxial connector 310 , and the connector serving as the AC+DC signal port is a triaxial connector 315 . In general, triaxial cables and connectors have an outer shield, a center conducting core known as the force, and an inner shield, known as the guard, between the force and the outer shield. The guard is kept at approximately the same electric potential as the force, thereby minimizing leakage current between the force and the guard.
[0024] In the bias tee network 300 of FIG. 3 , the capacitors 320 , 330 are coupled in series between the center conductor of the AC signal port coaxial connector 305 and the force of the AC+DC signal port triaxial connector 315 , thereby providing the AC path 304 through the bias tee 300 . An inductor 325 is coupled between the force of the DC signal port triaxial connector 310 and the force of the AC+DC signal port triaxial connector 315 , providing a DC path 303 through the bias tee 300 . A guard 335 of the DC signal port is connected to a guard 340 of the AC+DC signal port 315 , and also to the node between the capacitors 320 , 330 . In this configuration, low current performance of the bias tee 300 is better than that of the bias tee depicted in FIG. 2 . Because the guard 335 voltage follows the DC signal voltage, the capacitor 320 has 0 V across it. Therefore, the leakage current through the capacitor 320 is minimized, which improves the overall low current measurement capability of the bias tee 300 . However, because the capacitor 320 typically has a relatively large capacitance, the low current measurement capability of the bias tee 300 is still limited due to current noise resulting from the presence of the large capacitor 320 between the guard 335 and the DC signal.
[0025] FIG. 4 illustrates a configurable bias tee network 400 according to an embodiment of the invention. The bias tee network 400 includes a connector 405 serving as an AC signal port, a triaxial connector 410 serving as a DC signal port, and a triaxial connector 415 serving as an AC+DC signal port. The bias tee network 400 is bi-directional. The AC signal port connector 405 is typically a coaxial connector. The DC signal port and the AC+DC signal port triaxial connectors 410 , 415 each have a force and a guard. The DC signal port guard 435 is connected to the AC+DC signal port guard 440 .
[0026] The bias tee network 400 has a first electrical network 401 coupled between the force of the DC signal port 410 and the force of the AC+DC port 415 to provide a DC path 403 between these two ports of the bias tee 400 . In the bias tee network 400 of FIG. 4 , the electrical network 401 includes an inductor 425 . The bias tee network 400 also has a second electrical network 402 coupled between the force of the AC+DC signal port 415 and the center conductor of the AC signal port 405 . This second electrical network 402 includes a capacitor 420 , a switch 445 , and a capacitor 430 coupled in series. The capacitor 430 is coupled between the center conductor of the AC signal port 405 and the guards 435 , 440 . The capacitor 420 and the switch 445 are coupled in series between the force of the AC+DC signal port 415 and the guards 435 , 440 . With the switch 445 closed, the electrical network 402 provides an AC path 404 through the bias tee 400 between the AC signal port 405 and the AC+DC signal port 415 . With the switch 445 open, the AC path 404 is decoupled, or otherwise disconnected.
[0027] With the switch 445 closed, the capacitor 420 is said to be “guarded by” the DC signal in the DC path 401 through the bias tee 400 . That is, because the voltage at the guard 435 follows the voltage at the force of the DC signal port 410 , there is 0 V across the capacitor 420 , thereby minimizing the leakage current through the capacitor 420 . However, with the switch 445 closed, the performance of the bias tee network 400 when measuring DC low currents may still be negatively impacted by current noise. Current noise may be generated because the capacitor 420 typically has a relatively large capacitance. Preferably, the switch 445 is designed or selected such that, when open, the parasitic capacitance of the switch 445 is much lower than the capacitance of the capacitor 420 . Therefore, by opening the switch 445 , the AC path 404 is disconnected and current noise is reduced, thereby improving the performance of the bias tee network 400 when used for low current measurements.
[0028] FIG. 5 illustrates a configurable bias tee network 500 according to another embodiment of the invention. Like the bias tee network 400 depicted in FIG. 4 , the bias tee 500 of FIG. 5 has an electrical network 502 coupled between the force of an AC+DC signal port triaxial connector 515 and the center conductor of an AC signal port 505 . The electrical network 502 includes a switch 545 that, when closed, provides an AC signal path 504 through the bias tee 500 , and that, when opened, disconnects the AC path 504 to effect a performance improvement for low current measurement applications by reducing current noise that may be generated by a capacitor 520 .
[0029] The bias tee 500 also has an electrical network 501 coupled between the force of the AC+DC signal port triaxial connector 515 and the force of a DC signal port triaxial connector 510 . The electrical network 501 includes an inductor 525 and a switch 550 coupled in series such that when the switch 550 is closed, the electrical network 501 provides a DC signal path 503 through the bias tee 500 . Opening the switch 550 creates a high impedance in the DC path 503 , thereby improving the performance of the bias tee 500 for high impedance AC measurements. A resistor 555 is coupled in parallel with the switch 550 to enable the bias tee 500 to still have some reduced current DC bias capability even when the switch 550 is open.
[0030] In operation, one method of using the bias tee 500 includes opening either the DC path 503 , or the AC path 504 , and then measuring a signal conveyed through the non-opened path. Measurements may be made at, respectively, the AC signal port 505 , or the DC signal port 510 , for example. Opening the DC path 503 may include opening the switch 550 . The switch 550 may be opened in response to a generated DC path switch control signal Likewise, opening the AC path 504 may include opening the switch 545 . The switch 545 may be opened in response to a generated AC path switch control signal.
[0031] Both the switches 545 , 550 are preferably designed or selected to be switches with very low leakage current. One design consideration is the specified impedance of the switch. For example, if the switch has a specified impedance of 1 GΩ from control to output, at 100 V, a current of 100 nA will flow to the output. Such a leakage current may be unacceptable for the bias tee 500 to be used for low current measurements. In practice, it may be difficult to include switches that enclose control and switch circuitry into one package, and that also have acceptably low enough leakage current. Therefore, the switches 545 , 550 are preferably designed or selected to be switches that have the control and switch circuitry separated and isolated, such as, for example, switches that are optically controlled.
[0032] FIG. 6 shows a configurable bias tee network 600 according to another embodiment of the invention. The bias tee 600 is similar to the bias tee 500 shown in FIG. 5 , except that in the bias tee 600 , a switch 645 in an AC signal path 604 is activated by a photocell 670 , and a switch 650 in a DC signal path 603 is activated by a photocell 675 . The photocell 670 responds to an isolated control circuit 660 and the photocell 675 responds to an isolated control circuit 665 . The output of control circuits 660 , 665 may include, for example, light from light-emitting diodes (LEDs). Preferably, the control circuits 660 , 665 are insulated from the respective photocells 670 , 675 by a very high impedance material, such as, for example, air. In some embodiments, a single control signal may be input to both control circuits 660 , 665 .
[0033] In operation, generating an output from the control circuits 660 , 665 may be used to control the switches 645 , 650 , respectively. Generating an output from control circuits 660 , 665 may include generating a DC bias voltage.
[0034] FIG. 7 illustrates a configurable bias tee network 700 , according to another embodiment of the invention, providing self-contained switch control. The structure of the bias tee 700 is similar to the bias tee 600 shown in FIG. 6 , except that in the bias tee 700 , the inputs of control circuits 760 , 765 are coupled to the input of an AC signal port 705 . Because an AC signal (not shown) input to the AC signal port 705 is AC-coupled to the bias tee 700 , and because the AC signal may have its own DC bias level, controlling this DC bias level may be used to selectively drive the control circuits 760 , 765 . Although the control circuits 760 , 765 are illustrated in FIG. 7 as LEDs, the control circuits 760 , 765 may be designed and arranged in a variety of different configurations to effect different switch control logic for the photocells 770 , 775 , activating, respectively, the switches 745 , 755 . Preferably, the current needed to drive the control circuits 760 , 765 is relatively low, so that the impedance of the control circuits does not interfere with the measurements for which the bias tee 700 is used. Additionally, in the case where the control circuits 760 , 765 are LEDs, these LEDs are preferably optically isolated from each other, so as to prevent crosstalk.
[0035] Finally, FIG. 8 illustrates a configurable bias tee network 800 , according to another embodiment of the invention. The bias tee 800 is similar to bias tee 500 depicted in FIG. 5 in that the bias tee 800 of FIG. 8 has an electrical network 802 —including a capacitor 820 , a switch 845 and a capacitor 830 coupled in series—coupled between the force of an AC+DC signal port triaxial connector 815 and the center conductor of an AC signal port 805 . The capacitor 830 is guarded by a guard 835 of a DC signal port triaxial connector 810 and a guard 840 of the AC+DC signal port triaxial connector 815 . The switch 845 is arranged to provide an AC signal path 804 through the bias tee 800 when closed, and to disconnect the AC signal path 804 when opened.
[0036] The bias tee 800 also has an electrical network 801 coupled between the force of the DC signal port 810 and the force of the AC+DC signal port 815 , providing a DC signal path 803 through the bias tee 800 . The electrical network 801 includes a pair of diodes 860 , 865 and a resistor 855 coupled in parallel. The diodes 860 , 865 are coupled in opposite polarity to each other. This configuration gives the bias tee 800 improved AC high impedance measurement capability when DC signal current is low, but also allows the bias tee 800 to supply a high DC bias current with a reduction in AC high impedance measurement capability. Preferably, the DC drop though diodes 860 and 865 is calibrated out in the measurement system (not shown) in which the bias tee 800 is used, or remote sense capability is added to correct for the drop. Other embodiments of the invention add remote sense capability to the bias tees 400 , 500 , 600 , and 700 , described above.
[0037] It will be appreciated from the forgoing discussion that the invention provides significant advances in bias tee performance. Although specific embodiments of the invention have been illustrated and described for purposes of illustration, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the invention should not be limited except as by the appended claims.
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Bias tees, according to certain embodiments of the present invention, include switches in the AC signal path, the DC signal path, or both, to improve the capability of the bias tees to be used for high impedance AC measurement, low current DC measurement, or both. Optical control of the switches, as well as control of the switches using a DC bias present within the AC signal input to the bias tee, is described. Including a set of diodes into the DC signal path, rather than a switch, provides enhanced capability of the bias tee to be used for high impedance AC measurements.
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This application claims benefit to U.S. provisional application Ser. No. 60/101,702 filed Sep. 25, 1998.
BACKGROUND
1. Technical Field
This disclosure relates to surgical systems and, more particularly to an improved ultrasonic surgical apparatus for ultrasonically fragmenting tissue.
2. Background of Related Art
Devices which effectively utilize ultrasonic energy for a variety of applications are well-known in a number of diverse arts. The application of ultrasonically vibrating surgical devices used to fragment and remove unwanted tissue with significant precision and safety has led to the development of a number of valuable surgical procedures. Accordingly, the use of ultrasonic aspirators for the fragmentation and surgical removal of tissue from a body has become known. Initially, the technique of surgical aspiration was applied for the fragmentation and removal of cataract tissue. Later, such techniques were applied with significant success to neurosurgery and other surgical specialties where the application of ultrasonic technology through a handheld device for selectively removing tissue on a layer-by-layer basis with precise control has proven feasible.
Certain devices known in the art characteristically produce continuous vibrations having a substantially constant amplitude at a predetermined frequency (i.e 20-30 kHz). Certain limitations have emerged in attempts to use such devices in a broad spectrum of surgical procedures. For example, the action of a continuously vibrating tip may not have a desired effect in breaking up certain types of body tissue, bone, etc. Because the ultrasonic frequency is limited by the physical characteristics of the handheld device, only the motion available at the tip provides the needed motion to break up a particular tissue. The limited focus of such a device may render it ineffective for certain applications due to the vibrations which may be provided by the handheld device. For certain medical procedures, it may be necessary to use multiple hand held devices or it may be necessary to use the same console for powering different handheld devices.
Certain devices known in the art characteristically produce continuous vibrations having a substantially constant amplitude at a frequency of about twenty to about thirty kHz up to about forty to about fifty kHz. The amplitude is inversely proportional to frequency and directly proportional to wavelength. U.S. Pat. Nos. 4,063,557, 4,223,676 and 4,425,115 disclose devices suitable for the removal of soft tissue which are particularly adapted for removing highly compliant elastic tissue mixed with blood. Such devices are adapted to be continuously operated when the surgeon wishes to fragment and remove tissue, and generally is operated by a foot switch.
A known instrument for the ultrasonic fragmentation of tissue at an operation site and aspiration of the tissue particles and fluid away from the site is the CUSA model System 200 Ultrasonic Aspirator manufactured and sold by Valleylab, Inc. of Boulder, Colo., a subsidiary of U.S. Surgical Corporation; see also U.S. Pat. No. 4,827,911. When the longitudinally vibrating tip in such an aspirator is brought into contact with tissue it gently, selectively and precisely fragments and removes the tissue. Advantages of this unique surgical instrument include minimal damage to healthy tissue in a tumor removal procedure, skeletoning of blood vessels, prompt healing of tissue, minimal heating or tearing of margins of surrounding tissue, with minimal pulling of healthy tissue, and excellent tactile feedback for selectively controlled tissue fragmentation and removal is provided.
In many surgical procedures where ultrasonic fragmentation instruments are employed additional instruments are required for tissue cutting and hemostasis at the operation site. For example, hemostasis is needed in desiccation techniques for deep coagulation to dry out large volumes of tissue and also in fulguration techniques for spray coagulation to dry out the surface of tissues.
The apparatus disclosed in U.S. Pat. Nos. 4,931,047 and 5,015,227 provide hemostasis in combination with an ultrasonically vibrating surgical fragmentation instrument and aspirator. The apparatus effectively provide both a coagulation capability and an enhanced ability to fragment and aspirate tissue in a manner which reduces trauma to surrounding tissue.
U.S. Pat. No. 4,750,488 and its two continuation Patents, 4,750,901 and 4,922,902 disclose methods and apparatus which utilize a combination of ultrasonic fragmentation, aspiration and cauterization.
In an apparatus which fragments tissue by the ultrasonic vibration of a tool tip, it is desirable, for optimum efficiency and energy utilization, that the transducer which provides the ultrasonic vibration should operate at resonant frequency. The transducer design establishes the resonant frequency of the system, while the generator tracks the resonant frequency. The generator produces the electrical driving signal to vibrate the transducer at resonant frequency. However, changes in operational parameters, such as, changes in temperature, thermal expansion and load impedance, result in deviations in the resonant frequency. Accordingly, controlled changes in the frequency of the driving signal are required to track the resonant frequency. This is controlled automatically in the generator.
During surgery, fragmentation devices, such as the handpieces described above, are used internally to a patient. A surgeon manipulates the handpiece manually at an operative site, and therefore the handpiece itself may reduce visibility of the operative site. It would therefore be advantageous to provide an apparatus with the above described features with a smaller profile such that a greater field of view is provided for the surgeon at the operative site.
SUMMARY
An improved ultrasonic surgical apparatus having reduced size includes an ultrasonic handpiece. An ultrasonic fragmenting tool is mounted within the handpiece, the tool having a vibratable tip adapted for ultrasonically fragmenting tissue at a surgical site of a patient. A transducer is mounted within the handpiece and coupled to a connecting body. The connecting body is coupled to the tip for transmitting ultrasonic waves to the tip from the transducer, the tip and the connecting body being constructed of titanium or its alloys. An aspirating system is connected to the handpiece for aspirating fluid and tissue fragmented by the tip from the surgical site. An irrigation system is connected to said handpiece for supplying irrigation fluid to the surgical site for suspending fragmented tissue by the tip.
Another improved ultrasonic surgical apparatus having reduced size includes an ultrasonic handpiece. An ultrasonic fragmenting tool is mounted within the handpiece, the tool having a vibratable tip adapted for ultrasonically fragmenting tissue at a surgical site of a patient. A transducer is mounted within the handpiece and coupled to a connecting body. The connecting body is coupled to the tip for transmitting ultrasonic waves to the tip from the transducer, the connecting body is coupled with the tip for transmitting ultrasonic waves at a frequency of at least 35,000 Hz to the tip from the transducer. An aspirating system is connected to the handpiece for aspirating fluid and tissue fragmented by the tip from the surgical site. An irrigation system is connected to said handpiece for supplying irrigation fluid to the surgical site for suspending fragmented tissue by the tip.
In alternate embodiments of the ultrasonic surgical apparatus systems described, the transducer may include a stack of magnetostrictive plates longitudinally disposed within the handpiece and responsive to an input frequency for vibrating the tip. The plates can be flat or gusseted and may be fabricated of nickel or alloys thereof. The entire acoustic vibrating assembly (the transducer and its associated components) determines the system frequency. A fluid supply for introducing cooling fluid to the fragmenting tool and/or the transducer may also be provided. The aspiration system may include a detachable aspiration line wherein the aspiration line is removable from the handpiece. The tip may include a cavity formed therein in fluid communication with at least one inlet port positionable at a location adjacent to the surgical site wherein the aspiration system aspirates fluid and tissue fragmented by the tip from the surgical site through the inlet port and the cavity. The handpiece is preferably between about 4.5 and about 6 inches in length, and is preferably cylindrical and between about 0.5 and about 0.7 inches in diameter. The transducer produces standing waves having a wavelength, λ, and the transducer may have a length of about λ/2, the tip have a length of about λ/4 and the connecting body may have a length of about λ/4.
These and other objects, features and advantages of the present disclosure will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments are described herein with reference to the drawings, wherein:
FIG. 1 is a perspective view of an ultrasonic surgical apparatus constructed in accordance with the present disclosure;
FIG. 2 is another perspective view of the ultrasonic surgical apparatus of FIG. 1 in accordance with the present disclosure;
FIG. 3 is a side cross-sectional view of the surgical apparatus of FIG. 1;
FIG. 4 is a top cross-sectional view of the surgical apparatus of FIG. 1;
FIG. 5 is a cross-sectional view taken at section line 5 — 5 of FIG. 3 showing a tip and a manifold in operative relationship;
FIG. 6 is a cross-sectional view taken at section line 6 — 6 of FIG. 3 showing the tip and the manifold;
FIG. 7 is a cross-sectional view taken at section line 7 — 7 of FIG. 3 showing a connector body and an aspiration line;
FIG. 8 is a cross-sectional view taken at section line 8 — 8 of FIG. 3 showing the connector body and the aspiration line;
FIG. 9 is a cross-sectional view taken at section line 9 — 9 of FIG. 3 showing a stack of plates for an ultrasonic transducer;
FIG. 10 is a cross-sectional view taken at section line 10 — 10 of FIG. 3 showing conductors for activating the transducer;
FIG. 11 is a cross-sectional view taken at section line 11 — 11 of FIG. 3 showing ports and receptacles for supplying cooling fluid and power, respectively to the apparatus;
FIG. 12 is a perspective view with parts separated of a stack assembly;
FIG. 13 is a perspective view with parts separated of a transducer coilform assembly;
FIG. 14 is a perspective view of a partially assembled transducer coilform assembly;
FIG. 15 is a perspective view with parts separated of a handpiece in accordance with the present disclosure; and
FIGS. 16 and 17 are perspective views of the surgical apparatus of FIG. 1, mounted in a tip torquing system.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present disclosure is directed to an apparatus for ultrasonically fragmenting and aspirating tissue in a surgical operation. The apparatus includes a handpiece used by a surgeon to direct fragmentation. The handpiece includes an ultrasonically actuated tip which fragments tissue to be carried away by an aspiration system. An irrigation system which provides cooling fluid to the tip is provided for maintaining temperature within an acceptable range. A cooling system for supplying cooling fluid to the internal active components of the handpiece may also be provided. The handpiece is advantageously reduced in size to permit better maneuverability by a surgeon and to permit a larger field of view during internal surgery through an open incision.
Referring now in specific detail to the drawings in which like reference numerals identify similar or identical elements throughout the several views, and initially to FIGS. 1 and 2, one embodiment of an apparatus for ultrasonically fragmenting and aspirating tissue is shown generally as apparatus 10 . Apparatus 10 is embodied in a conveniently held handpiece 12 , a longitudinal cross-sectional view of which is shown in FIG. 3 of the drawings. Handpiece 12 includes a housing 14 which may be a sterilizable plastic or metal, preferably plastic. Housing 14 connects to an irrigation flue 16 at a distal end portion. Flue 16 includes an irrigation port and connection line 18 therein communicating with an opening 20 at a distal end thereof. A tip 22 is shown at a distal end of handpiece 12 . Tip 22 is vibrated to fragment tissue during surgery as will be described in further detail hereinbelow.
An aspiration line 24 is shown mounted externally to housing 14 . Aspiration line 24 includes release tabs 26 for dismounting a distal end portion of aspiration line 24 . Further, a tab 28 is included on a proximal end portion of aspiration line 24 . Tabs 26 and 28 secure aspiration line 24 and irrigation line 18 to housing 14 and permit detachment of aspiration line 24 and irrigation line 18 from housing 14 .
Handpiece 12 is advantageously significantly reduced in size over known handpieces and provides additional tissue selectivity and better visibility in accordance with the present disclosure. Handpiece 12 is dimensioned at about 4.5 to about 6 in length and about 0.5 to about 0.7 in diameter. This represents at least a 30% reduction in length and width thereby making handpiece more maneuverable and more easily handled by a surgeon during use.
Referring to FIGS. 3 and 4, side (FIG. 3) and top (FIG. 4) longitudinal cross-sectional views of handpiece 12 are shown. Housing 14 encloses a resonant vibrator 30 to vibrate in the ultrasonic range, including an aspirating tool vibrating at its tip in the ultrasonic frequency range at a longitudinal amplitude in excess of about 5 mils (0.005 inch). To achieve such an effect in an instrument which can be conveniently held by a surgeon, transmission of excitation to tip 22 is performed at the same time such tip 22 acts as an aspirating inlet to effect the surgical removal of the undesired tissue through cavity 34 . A preaspiration hole or inlet 32 communicates with cavity 34 within tip 22 . During operation, irrigation fluid is supplied through irrigation port 18 into flue 16 . Flue 16 and tip 22 form an annular cavity 36 therebetween. Irrigation fluid is supplied to the distal end of tip 22 , drawn into inlet 32 , and removed by the aspiration system through cavity 34 and aspiration line 24 . Tissue and blood from the surgical site are removed through the distal opening to the cavity 34 .
Where highly compliant tissue mixed with blood is aspirated, there is the increased likelihood of occlusion of the aspiration conduit due to the coagulation of the blood. It is therefore desirable to provide as large an aspiration path as possible. In addition, vibration apparently acts to increase the rate of coagulation. It is therefore additionally desirable that the aspiration path or conduit should preferably have minimal changes of direction of flow and where such changes are required, they should be as gentle as possible.
Referring now to construction of the resonant vibrator 30 , vibrator 30 functions as a mechanical vibrating system mounted in handpiece 12 . The vibrating system includes a transducer 40 having a magnetostrictive stack 41 preferably composed of a nickel alloy sandwich of flat or gusseted nickel alloy plates responsive to magnetic fields. Electrical oscillating current supplied to a winding of a coil 39 induces mechanical oscillations in transducer 40 , such oscillations preferably being at the resonant frequency and having a maximum practical peak-to-peak stroke (amplitude) of about 0.0002 thousandth of an inch (0.2 mils) at a frequency of about 36 kHz. Due to limitations imposed by the physics of the system, as frequency increases in the ultrasonic range, the stroke that one is able to obtain in the transducer is reduced.
However, it is known in the art that if one desires to take the available stroke from the transducer and vary the stroke, an ultrasonic mechanical transformer may be used. The design of such a transformer which is fixedly attached to the transducer magnetostrictive stroke is taught, for instance, in U.S. Pat. No. RE 25,033, incorporated herein by reference.
The design of the transformer section must include and yield the preferred characteristics at the output portion of resonant vibrator 30 . In this regard, the output portion of vibrator 30 (the distal end of tool 44 ) may vibrate ultrasonically with a desired stroke (peak to peak) of at least 0.005 to 0.0085 inch (5-8.5 mils). The output portion may also, for surgical requirements, be rather long and slender, while for aspiration purposes it is preferred to have as large a cross-sectional flow area as possible to thereby minimize the possibility of occluding the aspiration conduit.
Resonant vibrator 30 further includes a connecting body 42 and a tool 44 . Stack 41 , connecting body 42 and tool 44 function as a three body system. It is therefore advantageous to have lengths of these bodies proportional to the half wavelength of the resonant frequency. The entire system length has a length equal to a multiple of λ/2. An increase in frequency permits a reduction in overall length. (λ=c/frequency). In a preferred embodiment, lengths of stack 41 , connector body 42 and tool 44 are about λ/2,λ/4 and λ/4, respectively. As handpiece 12 is held and manipulated by the surgeon in one of his hands, the size and weight of handpiece 12 is limited by the ability of the hand to delicately grasp and manipulate the instrument. Since handpiece 12 is desirably reduced in size to permit better control by the surgeon and to increase the surgeon's field of view during surgery, a reduced size apparatus 10 is preferred. A reduction in size of apparatus 10 is difficult to achieve due to physical limitations. Merely downsizing the components of prior art handpieces will result in a design deficient of power (minimal tip displacement) but with high gain (defined as displacement amplitude of a tool over the displacement amplitude of a connector body).
Proportionality to resonant wavelength as well as increased frequency due to reduced size are addressed by apparatus 10 by providing a shorter instrument having increased frequency. Advantageously, connecting body 42 and tool 44 are provided having a substantially similar density material which is high in strength. In so doing, power (tip displacement) is increased dramatically for tool 44 at the cost of gain. Surprisingly, gain is still markedly increased in apparatus 10 over the prior art handpieces despite this reduction. Tool 44 includes tip at its distal end portion. Therefore, tip 22 experiences the maximum amplitude of tool 44 . Displacements achieved reached between about 0.005 and about 0.0085 inch. Displacements of this amplitude were achieved for frequencies of about 35 kHz or greater.
High strength materials are preferred to handle stress induced in tool 44 and connecting body 42 at the above frequency. Therefore, metals such as titanium and its alloys are preferred. Further, since tool 44 is subjected to high stresses, tool 44 is tapered over most of its length to preferably reduce the stress to which the metal is subjected. Coatings may be applied to tool 44 to improve their characteristics.
Tool 44 , in terms of its length and its distributed mass, is a dynamic part of the resonant vibrator 30 which can magnify the 0.0002 inch stroke input induced in the magnetostrictive stack of transducer 40 to in excess of a 0.005 inch output at tip 22 . Connecting body 42 is a unitary structure also dynamically a part of resonant vibrator 30 which serves to connect transducer 40 to tool 44 and, more importantly, to serve to transmit and modify the stroke as it is dynamically transmitted from transducer to tool.
A node of motion of resonant vibrator 30 is located in the vicinity of the distal end of connecting body 42 at the interface between the connecting body 42 and the tool 44 . Nodes are locations of high stress and minimal displacement due to the standing waves ultrasonically produced by the transducer. Higher frequencies provide greater tissue selectivity during surgery. Also, power is increased (displacement) by applying increased strain to the materials of tool 44 and connecting body 42 .
Power equals force times velocity, and force is proportional to the product of stress and area. Thus, to maximize power of the mechanical resonant structure, the force in the system should be maximized by designing the system components to their endurance strength. The velocity of the resonant structure should also be maximized by maximizing displacement. This can be accomplished by designing as low of a gain vibrator (connecting body 42 and stack 41 ) that still allows for the desired displacement at the distal end of the tool 44 .
Handpiece 12 which includes vibrator 30 and connecting body 42 mounted therein may advantageously be reduced in size by using high strength materials having a substantially similar density for both tool 44 and connecting body 42 . A size reduction of about 30% can be achieved in so doing as well as an increased frequency of operation. Such reduction is size permits a surgeon to conveniently hold handpiece 12 in one hand and manipulate it more accurately for improved results during surgery, for example neurosurgery.
Connecting body 42 has flange 48 which functions to position the vibrator 30 in handpiece 12 . Flange 48 has O-rings 45 disposed thereabout thereby sealing and separating off a distal end portion of housing 14 for cooling fluid circulation. O-ring 52 engages connecting body 42 and seals irrigation fluid in flue 16 . Tool 44 and stack 41 threadably engage connector body 42 as shown in FIG. 3 .
During operation of handpiece 12 , heat is generated. To remove this heat, a transducer housing (coilform) 54 houses stack 41 and includes ports 56 at a proximal end portion for accessing stack with a cooling fluid to lower temperatures therein. Housing 54 further includes access ports 56 for supplying power to circuitry of transducer 40 .
FIGS. 5 and 6 are transverse cross-sectional views of tool 44 taken through section lines 5 — 5 and 6 — 6 in FIG. 3, respectively. Tool 44 is substantially circular and disposed within flue 16 (FIG. 5 ). Flue 16 supplies irrigation fluid to an operative site during surgery (FIG. 6 ). Since flue 16 is a hollow member, ridges 57 are included for strength and may contact tool 44 . Ridges 57 help to maintain flue 16 and tool 44 concentric.
FIG. 7 is a transverse cross-sectional view through connector body 42 taken at section lines 7 — 7 indicated in FIG. 3 . Aspiration line 24 communicates with cavity 34 of tool 44 by passing through connector body 42 . A space 60 is defined between connector body 42 and a cap 62 which engages flue 16 (FIG. 3) to permit vibrations of the system without contact between cap 62 and connector body 42 . Also, irrigation port 18 is shown.
Referring to FIG. 8, a transverse cross-sectional view of connector body 42 is shown section lines 8 — 8 indicated in FIG. 3 . Connecting body 42 is shown spaced apart from transducer housing 54 to permit vibrations therebetween. Aspiration line 24 is shown having a coupling 64 for releasing aspiration line 24 when tabs 26 are depressed.
FIG. 9, a cross-sectional view taken along section line 9 — 9 in FIG. 3, illustrates stack 41 having a plurality of magnetostrictive plates 68 . Stack 41 is disposed within transducer housing 54 which is disposed within a tube 70 . Conductors 72 are disposed in grooves 74 formed in transducer housing 54 . A conductive sheet 71 surrounds conductors 72 . Coil 39 is wrapped about transducer housing 54 for extending a magnetic field created by coil 39 . Housing 14 is also shown.
Referring to FIG. 10, a proximal end of stack 41 is shown as well as proximal ends of conductors 72 . Engagement pins 76 are shown in cross-section and engage conductors 72 to make an electrical connection thereto. Transducer housing 54 has flanges 77 extending therefrom with openings 78 formed in each flange to receive conductors 72 . A recess 80 formed in housing 14 receives a clip 82 for securing aspiration line 24 to housing 14 . Tab 28 on clip 82 is used to secure the flue tube 18 on the handpiece housing 14 . Clip 82 may be detached from housing 14 by unclipping.
As is shown in FIG. 11, engagement pins 76 are dimensioned and configured to receive plugs (not shown) of an electrical connector to supply power to stack 41 through conductors 72 and coil 39 (FIG. 3 ). Two ports 84 are provided for providing access to cavity adjacent to stack 41 . Cooling fluid may be introduced and removed as a heat transfer medium to reduce temperatures of stack 41 during operation. An antirotation block 86 is included to prevent rotation of end cap 73 within housing 14 . Aspiration line 24 includes a larger diameter tube thereon to provide easier maintenance of suction at the operative site.
A stack assembly 43 is shown in exploded detail in FIG. 12 . Stack 41 is assembled by stacking and connecting plates 68 and applying a sleeve 90 and an end cap 92 thereto. A threaded end cap 94 connects to a distal end portion of stack 41 . End cap 94 threadedly engages connector body 42 . The elements of stack assembly 43 may be brazed together to prevent separation.
Referring to FIGS. 13 and 14, an exploded and assembled view of a transducer housing assembly 88 is shown. Transducer housing (coilform) 54 includes grooves 74 and flanges 77 with openings 78 for receiving conductors 72 therein. Conductive sheet 71 is placed around coilform 54 . Engagement pins 76 are inserted into holes 98 formed in a proximal end portion of transducer housing (coilform) 54 . Pins 76 engage conductors 72 which provide electrical current to and thereby activate coil 39 . Sheet 71 is preferably a high conductivity metal, such as copper. Sheet 71 includes an extended portion 98 for connection to engagement pins 76 . Current is supplied by engagement pins 76 to conductors 72 passed through coil 39 and returned through other conductors 72 and engagement pins 76 . In this way current is directed through the coil 39 to create a magnetic flux.
Transducer housing (coilform) 54 is inserted within tube 70 and engages a flange 101 at a proximal end portion of housing 54 . Housing 54 is maintained and sealed within tube 70 by 0 -rings 100 . A fastener 102 further secures transducer housing 54 in tube 70 at its distal end portion by snapping into a groove 103 on the distal end portion of housing 54 . FIG. 14 shows transducer housing 54 partially assembled to show the placement of sheet 71 and conductors 72 . Extended portion 98 engages return pin 99 while the remaining pins 76 engage conductors 72 .
FIG. 15 shows assembly of handpiece 12 by threading tool 44 into stack assembly 43 to form the three masses for vibrator 30 (FIG. 3 ). Transducer housing assembly 88 is inserted in housing 14 and stack assembly 43 and transducer housing assembly 88 are attached to housing 14 . The interface between tool 44 and connecting body 42 is positioned near a node. Stack assembly 43 is slid into transducer housing assembly 88 inside housing 14 . At the connection area between stack assembly 43 and housing assembly 88 , O-ring seals 102 are used and secured by a clip 104 within an opening in the distal end portion of housing 14 . Cap 62 is coupled to housing 14 by a bayonet type coupling 106 . An O-ring 101 seals a distal end portion of the connector body 42 to cap 62 . A proximal end portion of cap 62 is sealed off with O-ring 109 . Flue 16 is attached to cap 62 .
Guide plates 110 communicate with ports 56 (FIG. 3) and engagement pin 76 locations (FIG. 3) to permit engagement by a plug (not shown) to supply cooling fluid and power to transducer assembly 88 . End cap 73 and a plug 112 fit into distal end portion of housing 14 . An O-ring 114 provides a seal between end cap 73 and housing 14 .
Aspiration line 24 is connecting to connecting body 42 in communication with tip 22 . Coupling 64 detachably connects aspiration line 24 to cap 62 . Clip 28 fits into groove 80 of housing 14 for securing aspiration line 24 thereto by connecting to a stepped tube 116 . A larger diameter tube 115 also connects to stepped tube 116 .
Referring to FIGS. 16 and 17, apparatus 10 is mounted in a fixture 130 for supporting apparatus 10 . Fixture 130 includes bracket 132 for supporting handpiece 12 at or near node on connecting body 42 . A handle 136 is provided for stabilizing supporting fixture 130 and apparatus 10 . Supporting fixtures facilitates the attachment and/or removal of tools 44 .
It will be understood that various modifications may be made to the embodiments disclosed herein. For example, compensation for tissue fragmentation may be provided to maintain the standing wave in apparatus 10 . Further, the compensation may be provided by a compensation circuit which supplies additional current when tip 22 is in contact with tissue to maintain the standing wave. Also, guidance systems may be used to assist a surgeon during surgery, particularly neurosurgery. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.
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An improved ultrasonic surgical apparatus includes an ultrasonic handpiece. An ultrasonic fragmenting tool is mountable within the handpiece, the tool having a vibratable tip adapted for ultrasonically fragmenting tissue at a surgical site of a patient. A transducer is mounted within the handpiece and coupled to a connector body. The connector body is coupled to the tip for transmitting ultrasonic waves to the tip from the transducer, the tip and the connector body being constructed of titanium or its alloys. An aspirating system is connected to the handpiece for aspirating fluid and tissue fragmented by the tip from the surgical site. An irrigation system is connected to said handpiece for supplying irrigation fluid to the surgical site for suspending fragmented tissue by the tip. Preferred embodiments include operational frequencies of about 36 kHz.
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BACKGROUND OF THE INVENTION
The present invention relates to a control valve for fuel injection devices for internal combustion engines, preferably Diesel engines, with a valve housing within which at least one piston is displaceable and which comprises stops for the piston.
Today's internal combustion engines, Diesel engines, in particular, require an injection process consisting of several individual injection actions for a reliable and clean mixture formation within the combustion chamber of the engine. These injection processes are divided into one or more pre-injections, a main injection and, perhaps one or more subsequent injections of the fuel. For producing the pre-injection fuel quantity, a control unit is employed which requires a high-cost electronic control system and which shows energy losses. Frequently, a damper is employed for producing the pre-injection fuel quantity. This damper, however, cannot be fully utilized in each step of the operation and shows severe deviating depending on the operational location. The reason for this is that the switching time of the control hydraulic is too long in the event of small injection quantities due to the design of the control elements and a small pre-injection quantity can, therefore, be produced only with the help of a significant control-technical structural design and expenditure.
Therefore, it is an object of the present invention to provide a control valve of the aforementioned kind such that a small pre-injection quantity of fuel can be produced at all operational locations without a high control-technical structural design and expenditure
SUMMARY OF THE INVENTION
This object is solved by the inventive control valve by providing at least one of the stops to be axially adjustable.
With the inventive control valve, at least one of the stops for the piston is axially displaceable. This determines the stroke of the piston and the time period in the respective end positions corresponding to the closed or opened up control valve. Because of the possibility to adjust the stop, the piston stroke can be varied, depending on what the requirements are. Thereby, the smallest injection quantities, particularly for the pre-injection, and, if necessary, also for a subsequent injection, can be precisely controlled in a simple way without negatively affecting the main injection. It is also possible to reduce leakage losses by correspondingly adjusting the position of the stop.
BRIEF DESCRIPTION OF THE DRAWINGS
The object and advantages of the present invention will appear more clearly from the following specification in conjunction with the accompanying schematic drawings in which:
FIG. 1 shows a longitudinal section of a injection device with an inventive control valve;
FIG. 2 and
FIG. 3 show an enlarged view of a longitudinal section of the inventive control valve at various valve lift positions;
FIG. 4 to
FIG. 6 show various embodiments of the control valve at various valve lift positions;
FIG. 7 and
FIG. 8 show further embodiments of the control valve in simplified illustrations.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described in detail with the aid of several specific embodiments utilizing FIGS. 1 through 8.
The fuel injection device is utilized in motor vehicles and its purpose is to supply fuel to an internal combustion engine, a Diesel engine, in particular. The fuel injection device has a control piston 1 which is provided in a housing 2 . The pressure medium is supplied to the control piston 1 by a control valve 3 which is connected to a control unit 4 . The control valve 3 is disposed on the housing 2 and projects with a projection 5 of a valve housing/valve body 6 into a recess 7 provided at the end face of the housing 2 . At least one annular seal 8 is provided at the external wall of the projection 5 and seals the projection 5 against the housing 2 . An annular cavity 9 is provided within the projection 5 and is line-connected to working connections A, B of the control valve 3 . The control valve 3 is controlled and monitored by the control unit 4 . Coils 10 , 11 of the control valve 3 can be supplied with current by means of the control unit 4 . A piston 12 of the control valve 3 is embodied as an anchor and can be displaced by the coils 10 , 11 in the desired direction. The piston 12 is axially displaceable between two stops 13 , 14 which are inserted into the end faces of the valve body 6 .
If the control valve 3 is closed, the control piston 1 abuts the projection 5 of the valve body 6 under the force of a compression spring 15 . FIG. 1 shows the control piston 1 in its starting position, displaced by the spring 15 , in which an injection valve body 16 of an injection valve 17 closes off nozzle openings 18 by means of which the fuel is fed to the combustion chamber of the internal combustion engine (not illustrated).
The control piston 1 is provided with a piston surface 19 which is acted upon by the system pressure p 1 . A central projection 20 is provided in the piston surface 19 . In the starting position, the control piston 1 abuts with the central projection 20 an axial central projection 21 the projection 5 .
At its opposite end, the control piston 1 is provided with a recess bore 22 at the bottom surface 23 of which a pressure transferring or intensifying piston 24 abuts. The pressure intensifying piston 24 has a smaller diameter than the control piston 1 and projects into a bore 25 of the housing 2 . The system pressure p 1 is intensified by the pressure intensifying piston 24 creating the larger pressure p 2 which acts on the injection valve 17 .
The compression spring 15 abuts the bottom surface of a shoulder 26 at an end of the pressure intensifying piston 24 . The compression spring 15 surrounds the pressure intensifying piston 24 and abuts with its other end the bottom 27 of a bore hole 28 of the housing 2 , whereby this bore hole 28 receives the control piston 1 .
When the internal combustion engine is operated the piston 12 of the control valve 3 is displaced by means of the control unit 4 that provides current to the coil 11 such that the hydraulic medium which is fed by a line 29 within the valve body 6 is pressurized. The hydraulic medium reaches the annular cavity 9 and acts with the system pressure p 1 upon the piston surface 19 of the control piston 1 . The recess bore 22 positioned opposite the piston surface 19 is relieved of pressure and is connected to the atmosphere by a bore opening 30 penetrating the housing 2 . Due to this design, the control piston 1 can be displaced against the force of the compression spring 15 by the system pressure p 1 . Thereby, the pressure intensifying piston 24 abutting the bottom surface 23 of the recess bore 22 is also displaced whereby the fuel within the bore 25 is pressed into a bore channel 32 by a fixedly connected distribution plate 31 . The bore channel 32 is provided within an insertion member 33 which is received by a threaded socket member 34 . The threaded socket member 34 is screwed onto the housing 2 and receives the injection valve 17 which projects out of the threaded socket member 34 . The distribution plate 31 is clamped by means of the threaded socket member 34 between the insertion member 33 and the housing 2 . The threaded socket member 34 extends under the insertion member 33 so that the insertion member 33 is pressed in the direction of the housing 2 when the threaded socket member 34 is screwed on.
The bore channel 32 extends from the distribution plate 31 through the insertion member 33 to an injection chamber 35 which is provided within the insertion member 33 and which is penetrated by the injection valve body 16 . An axial bore 36 is provided, adjoining the injection chamber 35 and leading to the nozzle openings 18 . The axial bore 36 has a larger diameter than the portion of the injection valve body 16 which projects into the axial bore 36 . The injection valve body 16 projects into a central receiving cavity 37 of the insertion member 33 . The central receiving cavity 37 is closed off at the opposite side by the distribution plate 31 . One end of a second compression spring 38 is supported on the distribution plate 31 and its other end rests on a shoulder member 39 . The shoulder member 39 is provided at the end portion of the injection valve body 16 that is positioned within the central receiving cavity 37 and the shoulder member 39 has a central projection 40 for centering the second compression spring 38 . The injection valve body 16 is axially guided with an enlarged portion 41 within the injection valve 17 and projects with this enlarged portion 41 into the injection chamber 35 . Within the injection chamber 35 the enlarged portion 41 goes over into a thinner end portion 42 .
The fuel reaching the injection chamber 35 by passing through the bore channel 32 exerts pressure upon the enlarged valve portion 41 , whereby the injection valve body 16 is pushed back against the force of the second compression spring 38 . The nozzle openings 18 are thus released from the injection valve body 16 so that the fuel can enter the combustion chamber.
Subsequent to the injection process, the piston 12 is displaced by activating the control valve 3 by means of the control unit 4 , in such a way as to relieve the pressure in the annular cavity 9 into the tank. A back pressure valve 43 provided within the distribution plate 31 is opened up by the low pressure that is created on the return stroke of the pistons 1 , 24 , whereby fuel is taken in from a fuel container (not illustrated) through an opening 44 within the threaded socket member 34 and through an adjoining channel 45 within the insertion member 33 . The fuel reaches the bore 25 via the distribution plate 31 so that the fuel can be conveyed to the nozzle openings 18 during the next stroke of the pressure intensifying piston 24 in the manner described. The channel 45 also opens into the central receiving cavity 37 of the insertion member 33 .
When the piston 12 of the control valve rests against the stop 13 , the two working connections A, B of the control valve 3 are separated from the line 29 by the piston 12 . The piston 12 takes this position when the two pistons 1 , 24 are pushed back into the starting position illustrated in FIG. 1 by the spring force in the described manner. The hydraulic medium in the annular cavity 9 is pushed toward the tank connection T via the line connecting the annular cavity 9 and the tank connection T, as is indicated by the flow arrows in FIG. 2 . When the injection process takes place, the piston 12 is displaced to such an extent that it rests against the opposite stop 14 . In this position, the working connections A, B are connected to the line 29 while the tank connection T is separated from the bores leading into the annular cavity 9 . Thereby, the hydraulic medium can enter the annular cavity 9 via the working connections A, B and the bores.
The injection process is controlled by the control valve 3 which is a solenoid valve in the illustrated embodiment. However, also other types of valves, for example, piezo valves, can be utilized as control valves. The control valve according to FIGS. 2 to 4 is provided with the opposite stop 14 to be axially adjustable in order to vary the displacement distance of the piston member depending on what the requirements are. A precise control of the injection with respect to timing and quantity is possible by means of the piston stroke. The opposite stop 14 is embodied as an anchor which is surrounded by a valve coil 46 provided within the valve body 6 . The valve coil 46 is connected to the control unit 4 . The opposite stop 14 has a socket portion 47 which is guided to be axially displaceable within a valve bore 48 of the valve body 6 . The socket portion 47 is provided with a radially outwardly facing flange 49 at its end facing away from the piston 12 .
In FIG. 2, the opposite stop 14 is positioned such that the piston 12 can perform a large stroke. The piston 12 is displaced in the described manner by the coils 10 or 11 in order to convey the hydraulic medium through the line 29 into the annular cavity 9 , respectively, in order to relieve the annular cavity 9 to the tank. The stop 13 of the control valve 3 is axially fixedly connected to the valve body 6 .
FIG. 3 shows the opposite stop 14 in its inwardly displaced position in which it abuts with its flange 49 the end face of the valve body 6 . The socket portion 47 is inwardly displaced into the valve body 6 to such an extent that it is spaced only slightly from the piston 12 . Thus, only a shortened piston stroke is available for the piston 12 . For displacing the opposite stop 14 , the valve coil 46 is provided with current, controlled by the control unit 4 . The control valve 3 can be embodied such that the displaceable opposite stop 14 is continuously displaceable relative to the piston 12 .
FIGS. 2 to 4 show the valve position in its opened stage. A varying opening diameter can be achieved by varying the position of the opposite stop 14 so that the valve can be excellently adjusted to the various requirements of pre-injection, main injection and subsequent injection. Furthermore, the response time of the control valve 3 is reduced by a shorter valve lift; this is also advantageous with respect to an improved control of the fuel amounts.
FIG. 5 shows a closed position of the control valve 3 . Also in this closed position of the control valve 3 , the position of the piston 12 can be changed. For this purpose, the stop 13 can be displaced by a coil 50 which is arranged in the valve body 6 and is also connected to the control unit 4 . The stop 13 is also provided with a socket portion 51 having a radially outwardly facing flange 52 at one end face. By supplying the coil 50 with current, this stop 13 can be displaced into any desired position. The stop 13 can, for example, be shifted into a position in which the piston 12 creates a larger overlap of the valve control edges, thereby achieving a reduction of oil leakage. In order to avoid that the fuel injection is affected, the stop 13 can be displaced outwardly into its original position shortly before the injection starts.
In order to shift the piston 12 into different positions when the control valve 3 is closed off, only the stop 13 is provided to be axially displaceable. In contrast to the previous embodiment, the opposite stop 14 is fixedly connected; thus its position cannot be changed. In the resting position of the piston 12 and when the control valve 3 is closed off, the piston 12 is positioned at a distance from the opposite stop 14 so that the piston 12 can be displaced for the injection process into the direction of the opposite stop 14 to the extent desired by supplying the coils 10 or 11 with current.
As is shown in FIG. 6, it is also possible, however, to provide both stops 13 , 14 to be axially displaceable. In that event, the valve body 6 is provided with the two coils 46 and 50 by which the stops 13 , 14 can be displaced to the desired extent. In this embodiment, a combination of the variation of the piston stop is, therefore, ensured when the control valve 3 is opened and when it is closed.
FIG. 7 shows a schematic view of a portion of the piston 12 of the control valve 3 . A position of the piston 12 is illustrated in which it exposes an opening cross section 53 (hatched area) of a bore. This bore is provided with a constant width in the displacing direction 54 of the piston 12 so that the opening cross section 53 is constantly enlarged when the piston 12 is displaced. In such an embodiment, it is not possible to influence the travel-volume characteristic line of the control valve 3 .
FIG. 8 illustrates the possibility to influence this characteristic line by a particular special design of the bore. It has a T-shaped cross section. If the piston 12 is located in the position illustrated in FIG. 8, it overlaps the wider portion 55 of the bore and only exposes the narrower opening cross section 56 (hatched area). Thereby, only a small quantity of hydraulic medium is initially conveyed. As soon as the control edge 57 of the piston 12 reaches the area of the significantly wider portion 55 , the flow quantity of the hydraulic medium is immediately increased.
With the control valves 3 described herein, a control of the smallest injection quantities for the pre-injection and, if provided for, also for a subsequent injection is possible without having a negative impact on the main injection. By displacing the piston 12 when the control valve 3 is closed, leakage losses can be reduced. The stops can be adjusted irrespective of the type of valve employed. The stops can be continuously adjusted to reach any desired position so that the control valve 3 can be designed according to the most different requirements. The control valve described herein can be utilized in any area in which varying opening cross sections are required, e.g., in adjustment devices for cam shafts.
The specification incorporates by reference the disclosure of German priority document 199 16 658.7 of Apr. 14, 1999.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.
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The present invention relates to a control valve, especially for fuel injection devices for internal combustion engines, preferably diesel engines, with a valve housing within which at least one piston is displaceable and which comprises stops for the piston, wherein at least one of the stops is axially displaceable.
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BACKGROUND OF THE INVENTION
In most instances, commercial lighting fixtures are employed in suspended ceiling systems wherein a framework of inverted "T" bars or the like are utilized to support the entire ceiling system as well as the lighting fixtures. In some ceiling systems, the bottom face of the "T" bar is left exposed to provide a grid-like appearance to the ceiling system. In those types of installations, simple lay-in fixtures are employed which are supported directly by the "T" bar flanges, as are the acoustical ceiling tiles. In other systems, it is preferred that the bottom face of the "T" bar ceiling support system be hidden in order to avoid the grid appearance provided by the exposed "T" bar system. In the latter case, the acoustical ceiling tiles generally have a horizontal slot in their side edges which permits the acoustical tile, when placed on the "T" bars, to hide half of the "T" bar flange face while the adjacent ceiling tile will hide the other half of that flange face. Where lighting fixtures are employed in this type of ceiling system, it is generally required that after the luminaire is mounted within the ceiling system on the supporting "T" bar framework, an exterior flange must then be secured to the luminaire in order to hide the flanges of the "T" bar adjacent the opening in which the lighting fixture is mounted.
Another method sometimes employed to hide the ceiling grid system is to employ separate steel or vinyl holding strips which are mounted directly to the flange of the "T" bar adjacent the luminaire to provide the framework for the luminaire as well as hide the grid framework. Another method of providing this shielding or concealing of the "T" bar framework is by employing a luminaire with a complex door frame which provides both the luminaire door with its appearance frame and also carries both the air return structure and a second outer frame, also secured to the door frame which extends outwardly and shields the "T" bar framework from view.
Each of the foregoing systems provides either a complex system from the standpoint of mounting or an expensive system from the standpoint of luminaire manufacture.
SUMMARY OF THE INVENTION
The foregoing deficiencies of the prior art luminaire systems for concealing the "T" bar support structure have been obviated by the present invention which provides a luminaire which carries on the housing thereof an integral appearance frame which underlies and conceals the ceiling support framework from view while also having the facility of being simply and easily installed by one man without the use of tools and the like to add additional parts to the luminaire after it is installed on the "T" bar ceiling system.
The foregoing is accomplished by providing an asymmetrically mounted, recessed lighting fixture which conceals the ceiling support framework from view, and includes a top wall, a pair of sidewalls and a pair of end walls which define a bottom opening. An appearance framework is connected to the bottom edge of each of the sidewalls and the end walls and is constructed and arranged to underlie and conceal, at least in part, the ceiling support framework. A framed refractor is mounted within the bottom opening with the frame of the refractor being spaced a uniform distance from the appearance frame. Fluorescent lamp holders are mounted to each of the end walls with one of the end walls having an inwardly and horizontally directed portion which defines a shelf to support one end of the recessed lighting fixture on the ceiling support framework with means associated with the other end wall which coact with the ceiling support framework to support the other end of the recessed lighting fixture. The inwardly and horizontally directed portion of the one end wall underlies the fluorescent lamp holders and forms a recess which permits the entire luminaire to be swung around the framework into its mounting position while permitting the appearance frame connected to the bottom edge of each of the sidewalls and the end walls to underlie and conceal the ceiling support framework surrounding the luminaire in the ceiling system.
BRIEF DESCRIPTION OF THE DRAWING
Many of the attendant advantages of the present invention will become more readily apparent and better understood as the following detailed description is considered in connection with the accompanying drawing, in which:
FIG. 1 is a schematic side elevation view illustrating the method by which the fixture of the present invention is installed in a ceiling system;
FIG. 2 is a schematic side elevation view illustrating the luminaire of this invention mounted within a ceiling support system;
FIG. 3 is a bottom plan view of the luminaire of this invention mounted within a ceiling support system;
FIG. 4 is a partial top plan view with the central portion thereof broken away of the luminaire of this invention;
FIG. 5 is a sectional view taken along the line V--V of FIG. 4; and
FIG. 6 is a sectional view taken along the line VI--VI of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawing, wherein like reference characters represent like parts throughout the several views, there is illustrated schematically in FIGS. 1 and 2 the basic concept of this invention which provides an asymmetrically mounted recessed lighting fixture which is adapted to be mounted in a suspended ceiling system on the "T" bar framework while concealing the underside of that framework. Most suspended ceiling systems for commercial applications employ a metal "T" bar framework 10 to support the acoustical ceiling tiles and lighting fixtures. In some installations, the bottom faces of the "T" bar flanges are exposed to provide a lattice-work appearance in the ceiling of the room. In other installations, it is desired that these flange faces of the "T" bar system be hidden from view to provide a uniform planar surface at the ceiling. In the former situation, the mounting of lighting fixtures on the "T" bar framework presents no problem since the lighting fixture or luminaire is merely mounted on the flanges or upright portions of the "T" bar system and can be a simple "lay-in" type fixture. In the latter situation, slotted side edges in the ceiling tiles can be utilized to hide half of the flange face of the "T" bar sections surrounding the luminaire opening, but shielding of the flange face on the luminaire side presents a significant problem. As indicated previously, this can be accomplished by separate vinyl or steel shielding strips attached directly to the "T" bar, detachable trim which may be attached directly to the fixture body by screws or other mechanical means after the fixture is installed or by providing a separate complicated and cumbersome door frame to the luminaire which can underlie and shield the underside of the "T" bar flange.
As will be apparent as this description proceeds, the luminaire of this invention, generally designated 12, because of its asymmetric structure can be slipped between the "T" bar framework with, as illustrated in FIGS. 1 and 2, the left end 14 of the fixture slipped over the "T" bar and the luminaire then rotated into place while a hook support member 16 of the fixture is rotated over the "T" bar to support the other end 18 of the fixture 12.
The invention is illustrated in the form of a 4-lamp fluorescent luminaire, which includes generally a top wall 20 carrying a ballast housing 22 centrally thereof which encloses a ballast 24. The top wall may also include a plurality of vents 26 to vent the lamp enclosure defined by the top wall 20, the end walls 14 and 18 and a pair of sloped sidewalls 28. The end walls 14 and 18 along with the sidewalls 28 define a bottom opening in the luminaire housing which is closed off by a door which includes a door frame 30 and a refractor 32. The door frame 30 is hinged to one sidewall 28 and latched to the other sidewall 28 in a conventional manner to provide access to the lamp enclosure. Fluorescent lamps 34 are mounted within the lamp enclosure to the end walls 14 and 18 by lamp holders 36.
In accordance with this invention, the end wall 14 is designed to permit the lamp holders 36 associated with the end wall 14 to overlie a portion of that end wall to provide the novel mounting arrangement of this invention. The end wall 14 includes an upper vertical portion 38 extending downwardly from the top wall to an inwardly and horizontally directed portion 40 which extends inwardly to an inwardly and downwardly directed portion 42 extending from the inwardmost end of the horizontal and inwardly directed portion 40. An inwardly directed notched portion 44 and an outwardly directed flange portion 46 extend sequentially from the most inward end of the inwardly and downwardly directed portion 42. The outwardly directed flange portion 46 forms an appearance frame which coincides with and forms an extension of the remainder of the appearance frame 48 which is connected to the bottom edge of the end wall 18 and the sidewalls 28. The appearance frame 46, 48 completely surrounds and is spaced equidistantly from the door frame 30 and serves to underlie the half of the "T" bar flange adjacent the luminaire and shield that support frame 10 from view. The end wall 18 is of simple, planar, vertically oriented, sheet metal construction.
At the ends of the door frame 30 adjacent appearance frame 46 and 48, a space 50 is provided therebetween to permit air to be drawn through the opening 50, sweep the lamps 34 and exit into the plenum space above the luminaire through vents 26.
The combination of the ceiling tiles 52 with their extended flange 54 and the appearance frame members 46 and 48 completely shield or conceal the ceiling support framework defined by "T" bars 10.
As will be apparent from the foregoing, the luminaire of this invention being asymmetrically formed with an indentation or recessed portion in the lower part of the end wall 14, permits the luminaire to be mounted on a "T" bar grid frame work by simply rotating the luminaire into its mounted position by accommodating the framework "T" bar adjacent the end 14 of the luminaire in the recessed portion of that end wall. Hook members 16 rotatably mounted at 56 on the sidewalls 28 adjacent the end wall 18 can then be simply rotated to overlie the "T" bar framework adjacent the end 18 to complete the mounting of the luminaire within the ceiling support system. It will be apparent that other conventional mounting clips and methods can be used to support the end 18 of the luminaire on its adjacent support framework. In the mounted position, as illustrated in FIGS. 2 and 3, the appearance frame 46, 48 is immediately in position concealing its adjacent "T" bar flange from view and it is not necessary for a separate flange to be mechanically attached to the luminaire to form this function; nor is it required that a separate shielding means be applied directly to the framework flange as has been previously done to accomplish this shielding function. Neither does the luminaire require an enlarged and cumbersome door frame which carries a 2-part framework and its own air return slot required to accomplish the function of shielding the "T" bar framework from view.
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An asymmetrically mounted recessed lighting fixture which includes an integral appearance frame about the bottom edge thereof which underlies and conceals the ceiling support framework from view. The lighting fixture includes an undercut or recessed portion in one sidewall which permits mounting of the luminaire on the ceiling support framework without removal of the appearance frame which underlies and conceals the ceiling support framework.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of co-pending U.S. Provisional Application Ser. No. 61/791,615, filed Mar. 15, 2013, the full disclosure of which is hereby incorporated by reference herein for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present disclosure relates in general to dampening the opening and closing of hydraulic actuators for mud lift pump valves by providing cavities for hydraulic fluid accumulation in the actuators.
[0004] 2. Description of Prior Art
[0005] Subsea drilling systems typically employ a vessel at the sea surface, a riser connecting the vessel with a wellhead housing on the seafloor, and a drill string. A drill bit is attached on a lower end of the drill string, and used for excavating a borehole through the formation below the seafloor. The drill string is suspended subsea from the vessel into the riser, and is protected from seawater while inside of the riser. Past the lower end of the riser, the drill string inserts through the wellhead housing just above where it contacts the formation. Generally, a rotary table or top drive is provided on the vessel for rotating the string and bit. Drilling mud is usually pumped under pressure into the drill string, and is discharged from nozzles in the drill bit. The drilling mud, through its density and pressure, controls pressure in the well and cools the bit. The mud also removes formation cuttings from the well as it is circulated back to the vessel. Traditionally, the mud exiting the well is routed through an annulus between the drill string and riser. However, as well control depends at least in part on the column of fluid in the riser, the effects of corrective action in response to a well kick or other anomaly can be delayed.
[0006] Fluid lift systems have been deployed subsea for pressurizing the drilling mud exiting the wellbore. Piping systems outside of the riser carry the mud pressurized by the subsea lift systems. The lift systems include pumps disposed proximate the wellhead, which reduce the time for well control actions to take effect.
SUMMARY OF THE INVENTION
[0007] Disclosed herein is a system for lifting drilling mud from subsea to a drilling vessel that addresses vibratory forces generated by a valve actuator. In an example the system includes mud pumps selectively disposed subsea, a valve in a flow line that contains drilling mud from the wellbore, and an actuator coupled with the valve. The actuator is made up of an actuator body, a cylinder in the body, a piston in the cylinder, and a cavity in the body in unrestricted communication with the cylinder. In an embodiment, the cavity is strategically located in the actuator body so that when the piston reciprocates in the cylinder in response to application of fluid to a high pressure side of the piston, fluid on a low pressure side of the piston flows into the cavity. Optionally, the cavity is disposed proximate an end of the cylinder. Example cavities include a frustoconical chamber that projects axially away from an end of the cylinder and into the actuator body, an annular chamber that circumscribes the cylinder, and the like. The mud pump can include a housing with a bladder disposed inside to define a water space on one side that is in communication with a water supply line and a water discharge line, and a mud space on an opposite side that is in communication with a mud supply line and a mud discharge line, and wherein selectively providing pressurized water in the water supply line pressurizes mud in the mud space.
[0008] An alternative system for lifting drilling mud from a subsea wellbore includes a mud pump which is made of a housing, a water space in the housing, a mud space in the housing that is in pressure communication with the water space, a bladder mounted in the housing having a side in contact with the water space and an opposing side in contact with the mud space, and that defines a flow barrier between the water and mud space, a mud valve disposed in a line having drilling mud and that is in communication with the mud space, and a hydraulic actuator coupled with the mud valve. The actuator has an actuator body, a cylinder in the actuator body, a piston that reciprocates in the cylinder, and a cavity in the actuator body proximate an end of the cylinder, so that when the piston is at an end of a stroke, hydraulic fluid pools in the cavity to define a cushion that absorbs energy from a deceleration of the piston. The cavity can be an upper cavity that projects away from an end of the cylinder distal from a valve coupled to the hydraulic actuator. The cavity can alternatively be a lower cavity that is defined where an axial portion of the cylinder has an increased radius. Optionally, the system can have a first cavity that is strategically disposed to absorb energy when the piston is at the end of a stroke in a first direction, and a second cavity distal from the first cavity and strategically disposed to absorb energy when the piston is at the end of a stroke in a second direction. The mud valve can be a mud inlet valve that is disposed in the line between mud flowing from the wellbore and to the mud pump. The mud valve can also be a mud outlet valve that is disposed in the line between the mud pump and sea surface. The mud pump can further include a water inlet line having an entrance in selective communication with a source of pressurized water, and an exit in communication with the water space, and a water discharge line having an entrance in communication with the water space, and an exit in selective communication with a water effluent line.
[0009] An optional system for lifting drilling mud from a subsea wellbore includes a mud pump selectively disposed subsea that connects with a mud supply line that contains mud from the wellbore, and that connects to a discharge line having drilling mud discharged from the pump and that terminates above sea surface, a selectively openable and closeable mud inlet valve in the mud supply line, and an actuator. In this example the actuator has a body, a cylinder formed in the body, a piston reciprocatingly disposed in the cylinder, a stem connected between the piston and a valve member in the mud inlet valve, and a cavity in the body having an interface surface that borders a portion of an outer periphery of the cylinder. The cavity can project axially away from an end of the cylinder and the interface surface is substantially planar, or alternatively can project radially outward from an outer circumference of the cylinder and the interface surface is curved.
BRIEF DESCRIPTION OF DRAWINGS
[0010] Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
[0011] FIG. 1 is a side sectional view of an example of a subsea drilling system having a lift pump assembly and in accordance with the present invention.
[0012] FIGS. 2 and 3 are partial side sectional views of an example of a subsea pump for use with the drilling system of FIG. 1 in different pumping modes and in accordance with the present invention.
[0013] FIG. 4 is a side sectional view of a valve used with the pump of FIGS. 2 and 3 and in accordance with the present invention.
[0014] FIG. 4A is an enlarged side sectional view of a portion of the valve of FIG. 4 in accordance with the present invention.
[0015] While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0016] The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout.
[0017] It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.
[0018] Shown in FIG. 1 is a side partial sectional view of an example embodiment of a drilling system 10 for forming a wellbore 12 subsea. The wellbore 12 intersects a formation 14 that lies beneath the sea floor 16 . The wellbore 12 is formed by a rotating bit 18 coupled on an end of a drill string 20 shown extending subsea from a vessel 22 floating on the sea surface 24 . The drill string 20 is isolated from seawater by an annular riser 26 ; whose upper end connects to the vessel 22 and lower end attaches onto a blowout preventer (BOP) 28 . The BOP 28 mounts onto a wellhead housing 30 that is set into the sea floor 16 over the wellbore 12 . A mud return line 32 is shown having an end connected to the riser 26 above BOP 28 , which routes drilling mud exiting the wellbore 12 to a lift pump assembly 34 schematically illustrated subsea. Within the lift pump assembly 34 , drilling mud is pressurized for delivery back to the vessel 22 via mud return line 36 .
[0019] FIG. 2 includes a side sectional view of an example of a pump 38 for use with lift pump assembly 34 ( FIG. 1 ). Pump 38 includes a generally hollow and elliptically shaped pump housing 40 . Other shapes for the housing 40 include circular and rectangular, to name a few. An embodiment of a flexible bladder 42 is shown within the housing 40 ; which partitions the space within the housing 40 to define a mud space 44 on one side of the bladder 42 , and a water space 46 on an opposing side of bladder 42 . As will be described in more detail below, bladder 42 provides a sealing barrier between mud space 44 and water space 46 . In the example of FIG. 2 , bladder 42 has a generally elliptical shape and an upper open space 48 formed through a side wall. Upper open space 48 is shown coaxially registered with an opening 50 formed through a side wall of pump housing 40 . A disk-like cap 52 bolts onto opening 50 , where cap 52 has an axially downward depending lip 53 that coaxially inserts within opening 50 and upper open space 48 . A portion of the bladder 42 adjacent its upper open space 48 is wedged between lip 53 and opening 50 to form a sealing surface between bladder 42 and pump housing 40 .
[0020] A lower open space 54 is formed on a lower end of bladder 42 distal from upper open space 48 , which in the example of FIG. 2 is coaxial with upper open space 48 . An elliptical bumper 56 is shown coaxially set in the lower open space 54 . The bumper 56 includes upper and lower segments 58 , 60 coupled together in a clam shell like arrangement, and that respectively seal against upper and lower radial surfaces on the lower open space 54 . The combination of sealing engagement of cap 52 and bumper 56 with upper and lower open spaces 42 , 54 of bladder 42 , effectively define a flow barrier across the opposing surfaces of bladder 42 . Further shown in the example of FIG. 2 is an axial rod 62 that attaches coaxially to upper segment 56 and extends axially away from lower segment 58 and through opening 50 .
[0021] Still referring to FIG. 2 , a mud line 64 is shown having an inlet end connected to mud return line 32 , and an exit end connected with mud return line 36 . A mud inlet valve 66 in mud line 64 provides selective fluid communication from mud return line 32 to a mud lead line 68 shown branching from mud line 64 . Lead line 68 attaches to an annular connector 70 , which in the illustrated example is bolted onto housing 40 . Connector 70 mounts coaxially over an opening 72 shown formed through a sidewall of housing 40 and allows communication between mud space 44 and mud line 64 through lead line 68 . A mud exit valve 74 is shown in mud line 64 and provides selective communication between mud line 64 and mud return line 36 .
[0022] Water may be selectively delivered into water space 46 via a water supply line 76 shown depending from vessel 22 and connecting to lift pump assembly 34 ( FIG. 1 ). Referring back to FIG. 2 , a water inlet lead line 78 has an end coupled with water supply line 76 and an opposing end attached with a manifold assembly 80 that mounts onto cap 52 . The embodiment of the manifold assembly 80 of FIG. 2 includes a connector 82 , mounted onto a free end of a tubular manifold inlet 84 , an annular body 86 , and a tubular manifold outlet 88 , where the inlet and outlet 84 , 88 mount on opposing lateral sides of the body 86 and are in fluid communication with body 86 . Connector 82 provides a connection point for an end of water inlet lead line 78 to manifold inlet 84 so that lead line 78 is in communication with body 76 . A lower end of manifold body 86 couples onto cap 52 ; the annulus of the manifold body 86 is in fluid communication with water space 46 through a hole in the cap 52 that registers with opening 50 . An outlet connector 90 is provided on an end of manifold outlet 88 distal from manifold body 86 , which has an end opposite its connection to manifold outlet 88 that is attached to a water outlet lead line 92 . On an end opposite from connector 90 , water outlet lead line 92 attaches to a water discharge line 94 ; that as shown in FIG. 1 , may optionally provide a flow path directly subsea.
[0023] A water inlet valve 96 shown in water inlet lead line 78 provides selective water communication from vessel 22 ( FIG. 1 ) to water space 46 via water inlet lead line 78 and manifold assembly 80 . A water outlet valve 98 shown in water outlet lead line 92 selectively provides communication between water space 46 and water discharge line 94 through manifold assembly 80 and water outlet lead line 92 .
[0024] In one example of operation of pump 38 of FIG. 2 mud inlet valve 66 is in an open configuration, so that mud in mud return line 32 communicates into mud line 64 and mud lead line 68 as indicated by arrow A Mi . Further in this example, mud exit valve 74 is in a closed position thereby diverting mud flow into connector 70 , through opening 72 , and into mud space 44 . As illustrated by arrow A U , bladder 42 is urged in a direction away from opening 72 by the influx of mud, thereby imparting a force against water within water space 46 . In the example, water outlet valve 98 is in an open position, so that water forced from water space 46 by bladder 42 can flow through manifold body 86 and manifold outlet 88 as illustrated by arrow A Wo . After exiting manifold outlet 88 , water is routed through water outlet lead line 92 and into water discharge line 94 .
[0025] An example of pressurizing mud within mud space 44 is illustrated in FIG. 3 , wherein valves 66 , 98 are in a closed position and valves 96 , 74 are in an open position. In this example, pressurized water from water supply line 76 is free to enter manifold assembly 80 where as illustrated by arrow A Wi , the water is diverted through opening 50 and into water space 46 . Introducing pressurized water into water space 46 urges bladder 42 in a direction shown by arrow A D . Pressurized water in the water space 46 urges bladder 42 against the mud, which pressurizes mud in mud space 44 and directs it through opening 72 . After exiting opening 72 , the pressurized mud flows into lead 68 , where it is diverted to mud return line 36 through open mud exit valve 74 as illustrated by arrow A Mo . Thus, providing water at a designated pressure into water supply line 76 can sufficiently pressurize mud within mud return line 36 to force mud to flow back to vessel 22 ( FIG. 1 ).
[0026] In the examples of FIGS. 2 and 3 , included is a controller 100 shown in communication with actuators 102 , 104 , 106 , 108 respectively coupled with the valves 66 , 74 , 78 , 98 and that provide means for opening and closing valves 66 , 74 , 78 , 98 . In one example embodiment, controller 100 communicates commands to the actuators to selectively open and/or close valves 66 , 74 , 78 , 98 . In an embodiment, controller 100 includes an information handling system (IHS) that receives or contains instructions to selectively operate valves 66 , 74 , 78 , 98 .
[0027] FIG. 4 is a side sectional view of an example of actuators 102 , 104 used with mud inlet and exit valves 66 , 74 . Actuators 102 , 104 include an elongate body 110 having a cylinder 112 generally coaxial within body 110 . A piston 114 is set in the cylinder 112 and reciprocates therein for opening and closing valves 66 , 74 . Hydraulic lines 116 , 118 connect respectively to ports 120 , 122 shown formed laterally through a sidewall of the body 110 to the cylinder 112 . Hydraulic fluid in hydraulic lines 116 , 118 selectively flows into cylinder 112 via ports 120 , 122 for urging the piston 114 axially within the cylinder 112 . A valve stem 124 is shown having one end connected to an end of piston 114 proximate where actuator body 110 mounts onto a valve body 126 . An end of stem 124 opposite its connection to piston 114 connects to a valve gate 128 that reciprocates within a cavity of the valve body 126 to selectively open and close valve 66 , 74 .
[0028] FIG. 4A is a side sectional enlarged view of a portion of actuator 102 , 104 of FIG. 4 and illustrates an upper cavity 130 formed into actuator body 110 distal from valve body 126 . More specifically in the example of FIG. 4A , upper cavity 130 has a frusto-conical shape, is generally coaxial with cylinder 112 , and projects axially away from an upper end of cylinder 112 . Embodiments exist where the upper cavity 130 is formed in the sidewalls of cylinder 112 , such as by a localized increase in a radius of the cylinder 112 , or by grooves (not shown) that circumscribe the cylinder 112 or run axially to the cylinder 112 . As such, when piston 114 reaches an end of its stroke to open valve 66 , 74 and is proximate a closed end of cylinder 112 , fluid flows into upper cavity 130 to prevent forces from being generated by trapping fluid in an enclosed space. The upper cavity 130 can also absorb and/or attenuate impulse forces generated by the piston 114 that might otherwise be transferred to the surrounding structure. The trapped fluid thereby reduces noise and vibration during operation of the actuator 102 , 104 .
[0029] Body 110 includes a lower cavity 132 is shown formed that is axial distal from cavity 130 , and provides dampening when piston 114 is at the end of its down stroke and is closing valve 66 , 74 . Lower cavity 132 is defined where a radius of the cylinder 112 is increased along a discrete axial length of the body 110 proximate port 122 . Similar to upper cavity 130 , lower cavity 132 provides a space where a volume of hydraulic fluid can collect and absorb impulse forces that occur at the end of the stroke of piston 114 . In the example of FIG. 4A , upper cavity 130 absorbs a volume of fluid to prevent impulse forces from being generated at an end of an upstroke of piston 114 , and lower cavity 132 absorbs a volume of fluid to prevent impulse forces from being generated at an end of a downstroke of piston 114 . In the example of FIG. 4A , the upper and lower cavities 130 , 132 both have a surface that directly and wholly contacts an outer peripheral surface of cylinder 112 . Thus fluid in the cylinder 112 can flow unrestricted into the cavities 130 , 132 .
[0030] The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.
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Drilling mud is lifted subsea to a drilling vessel with a mud pump having an internal bladder. Applying pressurized water to one side of the bladder urges it against a quantity of the mud to impart a lifting force onto the mud. Mud flow to and from the pump is controlled by valves driven by actuators. The actuators include a piston in a cylinder, a stem that connects the piston to a valve member, and ports for supplying fluid to opposing ends of the piston for selectively reciprocating the piston. Cavities are strategically location in the cylinder for absorbing vibrational forces generated when the piston reaches an end of its stroke.
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FIELD OF THE INVENTION
The present invention relates to production of physically modified wool-like chemical filaments and textile products made therefrom and may be employed in all branches of the textile industry involved in the manufacture of woolen goods.
The invention can be most advantageously used in the production of various household and industrial goods in the textile, knitting and other industries.
Physical modification in this case implies changes in the cross-sectional shape of the filament or fibre attained through changes in the shape of the filament-forming holes in the spinneret.
Physical modification makes it possible to improve the physical, geometrical, physicochemical properties of the yarns and fibres. Besides, it enables the performance and appearance of goods made from these filaments to be enhanced.
The acute shortage of natural fibres as well as the steadily growing demands for comfort properties of textiles have given rise to wool-, silk-, cotton- and flax-like fibres, yarns and goods made therefrom.
Wool-like man-made fibres and yarns may be obtained by providing them with an elaborate coss-sectional configuration and by formation of an inner cavity due to spinning through a spinneret with a profiled filament-forming hole as well as by imparting crimp to a filament or fibre.
BACKGROUND OF THE INVENTION
At present there are known yarns obtained from ordinary spinnerets and featuring crimp necessary for wool-like fibres and filaments. The crimp is attainable either through the use of two or more components in the filamentary yarn with different shrinking and swelling properties or through asymmetric cooling thereof in a direction normal to its movement.
The known methods of imparting crimp to the filament are rather complicated since they call for special auxiliary contrivances.
There are also known spinnerets with a non-round configuration of the filament-forming holes which make it possible to produce hollow wool-like fibres and filaments with a non-round cross-section featuring certain wool-like properties: low heat conductivity, increased mechanical cohesion of individual fibres, bulk and opticl properties.
For instance, according to USSR Inventor's Certificate No. 286,130, there is known a spinneret for forming chemical hollow wool-like fibres, having a spinning hole made as a slot with a configuration of an open polygon provided with three branches, each being arranged at a right angle to one of the sides of the polygon.
Fibres formed by extrusion through the hole of the known configuration approximate, as to heat conductivity, volume weight and cohesion, natural wool, but the most essential characteristics determining their hygienic properties (capillarity, moisture conductivity) practically do not change. Moreover, fibres spun through the spinneret according to USSR Inventor's Certificate No. 286,130 lack crimp required for wool limitation. The mechanical crimp of the filament rapidly disappears during processing and in use. Therefore, these fibres are used, mainly, as additives to natural wool, their amount in the mixture not exceeding 30 percent. Thus, all chemical fibres and yarns known in the art do not exhibit all the properties inherent in natural wool, such as low heat conductivity, permanent crimp, adequate moisture conductivity, moisture capacity, and bulk.
BRIEF DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a spinneret for producing a chemical filament, having a spinning hole of such a configuration which will enable obtaining a filament exhibiting all properties inherent in natural wool, namely, low heat conductivity, permanent crimp, high hygienic properties (moisture absorption, capillarity, moisture desorption).
This and other objects are attained by forming a filament through a spinneret wherein a spinning hole is made as a slot having a configuration of an open polygon with a rectilinear portion adjoining, at a right angle at least one of the sides thereof, in which spinneret, in accordance with the invention, the configuration of the slot-shaped hole has at least one more element arranged at a right angle to the rectilinear portion.
The proposed configuration of the filament-forming hole makes it possible to produce a filament with a cross-section composed of two elements, one of the elements being formed by rectilinear branches the mutual arrangement whereof renders the elements L-shaped, T-shaped, cross-shaped or fork-shaped, and the other element having the form of a ring. Such a cross-sectional shape of the filament permits forming therein open capillary channels communicating with the outer surface of the fibre over its entire length. These capillary channels are formed in the open element of the filament cross-section. The presence of the capillary channels increases the moisture conductivity of the filament, capillarity, moisture capacity ensuring adequate hygienic properties of articles made from these filaments. The open polygon allows obtaining a cavity in the filament due to which low heat conductivity is provided. With such a configuration of the filament cross-section, said elements, by virtue of their different specific surface (per unit of dope mass), are cooled at different rates. Cooling of the element with the inner cavity is slower. This is determined by the presence of air (thermally nonconductive medium) therein and also by said element being shaped as a ring whereby the cooling takes place from the outer surface thereof.
At the same time, the element of the open polygon composed of rectilinear branches is cooled from both the outer and inner surfaces. Therefore, its cooling is faster.
As a result of this non-uniform cooling, a permanent crimp is developed in the filament similar to that of natural wool. In addition, the L-shaped, T-shaped, fork-shaped and cross-shaped branches ensure high bulk and cohesion of the filament.
Thus, as distinct from the wool-like chemical yarns known in the art, the filament obtained on the proposed spinneret exhibits all essential properties inherent in natural wool, namely, permanent crimp, low heat conductivity, high moisture conductivity, as well as high bulk and cohesion.
According to an alternative embodiment of the invention, the element of the configuration of the filament-forming hole in the spinneret, arranged at a right angle to the rectilinear portion, may have the shape of a rectilinear section.
As a result of formation of the filament through the spinneret with said configuration of the filament-forming hole, there is obtained a filament having a cross-section composed of two elements, one of which is either L-shaped or T-shaped and the other has the shape of a ring. Such a configuration of the cross-section, having two elements differing in shape makes it possible to obtain in the filament permanent crimp due to said elements of the filament being non-uniformly cooled. At the same time, the L-shaped or T-shaped element, together with the ring-shaped element, permit forming in the filament one or two equal and sufficiently deep oven capillary channels communicating with the outer surface of the filament.
The presence of one or two sufficiently deep open capillary channels provides for adequate sorption properties of the filament (increased capillarity, moisture desorption), approximating those of the natural wool.
At the same time, the inner cavity in the filament running along its entire length, formed by the open poygon makes it possible to impart low heat conductivity to the filament.
Moreover, the L-shaped or T-shaped element adds to the bulk and cohesion of the filament.
According to another embodiment of the invention, the element of the configuration of the filament-forming hole, made as a rectilinear section intersects the rectilinear portion. In this case, one end of the rectilinear portion adjoins the side of the polygon, the other end being free.
As a result of formation of the filament through the spinneret with the filament-forming hole of said configuration, there may be obtained a filament having a cross-section composed of two elements, one of which is cross-shaped and the other has the shape of a ring. Such a configuration of the cross-section ensures formation of two deep open capillary channels providing for adequate sorption properties of the filament, low heat conductivity and permanent crimp.
Besides, the free end of the rectilinear portion in the configuration of the cross-section of the filament allows imparting to the filamentary yarn composed of filaments of said cross-sectional shape increased bulk due to greater interfilament spacing.
According to still another embodiment of the invention, adjoining the rectilinear section intersecting the rectilinear portion at a right angle to this piece and as close as possible to the ends thereof are two rectilinear portions. Also, according to the invention, these rectilinear portions are directed aside from the polygon, thereby forming an element shaped as a three-pronged fork.
As a result of formation of the filament through the spinneret with such a filament-forming hole, there is produced a filament with a cross-section composed of two elements. One of these elements has the form of a three-pronged fork and the other, the form of a ring. The presence in the configuration of the filament cross-section of the element shaped as a three-pronged fork enables increasing the moisture conductivity and capillarity of the filament due to the greater number of capillary channels, i.e. due to the formation of two additional deep open capillary channels (four in number). Moreover, the presence of the element shaped as a three-pronged fork further increases the bulk of the filamentary yarn composed of filaments with such a configuration of the cross-section, because of the still greater interfilament spacing.
According to yet another embodiment of the invention, the element shaped as a three-pronged fork adjoins one of the vertices of the open polygon with its rectilinear portion; one more rectilinear portion may emerge from the same vertex at a right angle to the latter.
As a result of formation of the filament through such a filament-forming hole of the spinneret, there is produced a filament with the configuration of its cross-section being composed of the following elements: an element shaped as a three-pronged fork, an additional branch formed by the additional rectilinear portion emerging from the polygon vertex, and a ring-shaped element. This being the case, as distinct from the above cross-sections of the filament, the size of the ring-shaped element is approximately two times smaller. Moreover, the ring-shaped element is located in the right upper corner relative to the axis of symmetry of the cross-section of the filament, whereas the three-pronged element forms, together with the additional rectilinear branch, four deep open capillary channels. Besides, a less deep capillary channel is formed intermediate of the additional branch and the ring-shaped element. Due to this capillary channel, the sorption properties of the filament are improved. Due to a smaller size of the cavity and due to its circumferential arrangement with respect to the axis of symmetry of the cross-section, the cooling conditions of the filament are changed and fine crimp of the filament is attained, which is desirable for the production of a filamentary yarn of low linear density required for producing light fabrics used in hot and humid climates.
According to one more embodiment of the invention, adjoining said additional rectilinear portion emerging from the vertex of the polygon at a right angle thereto may be one more rectilinear portion whose free end is adjoined, in turn, by one more rectilinear portion directed towards the polygon, whereby an additional open polygon is formed. As a result of formation of the filament through such a hole in the spinneret, two open polygons form two cavities in the filament, whereas the three-pronged element forms in the filament four deep open capillary channels. The resulting filament exhibits higher stiffness and resilience and may be used in the production of pile fabrics with pile resistant to mechanical action.
According to still another embodiment of the invention, the part of the rectilinear portion through which the three-pronged fork adjoins the polygon and which is disposed intermediate of the fork and the polygon is, at least in the central part, intersected by one more rectilinear portion at a right angle.
As a result of formation of the filament through such a hole with two open polygons, formed in the filament are two approximately equal inner cavities, whereas due to the additional rectilinear portion formed in the configuration of the cross-section of the filament are two additional rectilinear branches ensuring, together with the three-pronged element, formation in the filament of six deep open capillary channels communicating, over the entire length of the filament, with the outer surface thereof. The additional rectilinear branches in the cross-section of the filament equalize the masses of two portions of the cross-section: the portion composed of the three-pronged element and additional rectilinear branches and the portion composed of two ring-shaped elements. This somehow reduces the filament crimp. However, due to the increased number of open capillary channel, the sorption properties are significantly enhanced. This provides for adequate ventilation of the space between the human body and the garment.
Also, according to the invention, emerging from the vertex of the open polygon in the configuration of the thread-forming hole may be simultaneously a rectilinear portion and an element shaped as a two-pronged fork formed by said rectilinear portions, at least the mid-portion of the rectilinear section of the two-pronged fork, disposed intermediate of the prongs and the vertex of the polygon, being intersected at a right angle by another rectilinear portion.
As a result of formation of the filament through such a hole, there is produced a filament with a cavity arranged circumferentially with respect to the filament axis. The two-pronged element of the cross-section of the filament and the rectilinear portions form five deep and one less deep open capillary channels communicating with the outer surface of the filament over its entire length. Due to the plurality of capillary channels and also due to a small cavity, this filament possesses high sorption properties and fine crimp and may be used in light fabrics and knitwear suitable for hot and humid climates.
In accordance with the invention, the filament yarn composed of filaments formed on the spinneret with said configurations of the filament-forming holes features a twist ranging from 10 to 1,500 T.P.M. Said twist is imparted to the filament yarn with the aim of improving its wool-like properties (moisture conductivity and resilience). A lower twist could decrease the angle of inclination of the capillaries with respect to the outer surface of the filament and impair the sorption properties thereof, whereas an excessively high twist could result in an overtight yarn having raised stiffness and, therefore, increased heat conductivity, decreased bulk and inadequate sorption properties. Hence, the proposed chemical wool-like filament yarn must have a twist lying within the proposed limits.
BRIEF DESCRIPTION OF THE DRAWINGS
Given below is a detailed description of the present invention with reference to the accompanying drawings, wherein:
FIG. 1 shows schematically an apparatus for forming wool-like polycaproamide filaments with the use of the proposed spinneret;
FIGS. 2, 4, 6, 8, 10, 12, 14 show embodiments of configurations of the cross-sections of filament-forming holes, enlarged view;
FIGS. 3, 5, 7, 9, 11, 13, 15 show, respectively, embodiments of cross-sectional configurations of the wool-like filaments, enlarged view.
DETAILED DESCRIPTION OF THE INVENTION
The wool-like filament is formed from any synthetic fibre-forming thermoplastic polymer such as polyamide, polyester, etc. Consider now the process of filament formation from polycaproamide.
The molten polymer is admitted into an apparatus 1 (FIG. 1) for continuous polymerization, then into an apparatus 2 for withdrawing the monomer. The molten polymer having a temperature of 250° to 270° C., a relative viscosity of 2.2 to 2.8 and a content of lowmolecular compounds of no more than 3.0 to 3.5% is forced, at a pressure of 60 to 100 kgf/cm 2 by means of a screw conveyor 3 to metering pumps 4. To prevent oxidation of the polymer, the process in its entirety takes place in the flow of nitrogen.
The metering pump forces the polymer through a filter and a spinneret 5. The jets of polymer emerging from the spinneret holes pass through cooling and spinning chambers 6 and 7 and under the effect of the cooling air solidify into filaments. The cooling air is admitted into the upper compartment of the cooling chamber 6 at a right angle to the movement of the filament. The temperature of the cooling air is 17° to 25° C., its velocity being 20 to 30 cm/s. The rate of forming is 2,500 to 3,500 m/min. The filaments, while contacting preparation discs 8, pass to first draw-off godets 9 and then to succeeding stretch godets 10 heated to 150°-200° C. The draw ratio lies between 2.5 and 4.0. The formed filament from the second stretch godets is wound onto a bobbin 11 weighing about 5 kg. The ambient conditions in the winding zone shall be maintained constant:
temperature, 20°±2° C.
specific humidity, 48±2%
Given below are examples of producing specific types of filaments from the same polymer with the use of spinnerets embodying the invention.
EXAMPLE 1
Formation of the wool-like polycaproamide filament is accomplished, as described above, through the spinneret 5 with the cross-sectional configuration of the filament-forming holes as shown in FIG. 2. The configuration of the slot representing the filament-forming hole is an open tetragon (12), with one of its sides, which is opposite the open one, adjoined, approximately in the mid-point thereof at a right angle thereto, by a first rectilinear portion (13). Adjoining the latter at a right angle thereto is one more rectilinear section (14).
As a result of formation of the filament through the spinneret with the spinning holes of such a configuration with an open tetragon, there is obtained an inner cavity extending over the whole length of the filament. For the open contour to become continuous in the process of forming, the size of the gap should constitute, approximately, from 1 to 5 slot widths.
To ensure a required size of the inner cavity, i.e., to obtain the desirable thermal insulation properties of the filament, the lengths of the tetragon sides should range from 0.5 to 1, with the sides being 0.3 to 1.5 mm long.
The mutually perpendicular portions (13) and (14) form, together with a tetragon side, an open capillary channel communicating with the outer surface of the filament over its entire length. To obtain deep open capillary channels, i.e., to ensure desirable hygienic properties, the length of the rectilinear portions 13 and 14 should range from 0.5 to 1.5 mm. The ratio of the length of the rectilinear portions to the slot width is from 3 to 9, the slot being 0.04 to 0.12 mm wide. Formation of the filament through the spinneret having said configuration of the holes is carried out from the molten polymer with a relative viscosity of 2.2 and a temperature of 260° C. The cooling air temperature is 18° C., its velocity being 20 cm/s. The rate of forming is 3,000 m/min; the draw ratio is 3.5. The second stretch godets are heated to 100° C.
As a result of formation of the filament through the spinneret with said configuration of the filament-forming hole, there is produced a filament having the cross-section, as is shown in FIG. 3, composed of two elements "A" and "B", the element "A" being L-shaped or T-shaped, the other element "B" being shaped as a ring, both the elements forming together deep open capillary channels communicating with the outer surface of the filament over the entire length thereof.
The presence of capillary channels increases the moisture conductivity of the filament, capillarity and moisture capacity ensuring adequate hygienic properties of articles made from these filament yarns. The inner cavity contributes to low heat conductivity of the filament.
With such a shape of the cross-section of the filament, said elements "A" and "B" are cooled at different rates due to their different specific surfaces (per unit of the dope mass). The cooling of the ring-shaped element "B" having an inner cavity is slower. This is conditioned by the presence of air (i.e., thermally non-conductive medium) in the latter and also by that the element has the shape of a ring due to which the cooling occurs only from the outer surface. The element "A" of the open contour composed of the rectilinear branches is cooled from both the outer and inner surfaces. Therefore, its cooling proceeds at a higher rate. Due to such a non-uniformity of cooling of the filament, permanent crimp appears in the filament reminiscent of that of natural wool.
The inner cavity and capillary channels in the filament ensure adequate thermal and sorption properties thereof, the permanent crimp making the filament properties approximate those of the natural wool.
For mechanical and physical characteristics, sorption and thermal properties of the formed wool-like filaments refer to Table 1, column 1.
EXAMPLE 2
Formation of the wool-like polycaproamide filament is accomplished, as described above, through the spinneret 5, the cross-section of one of the filament-forming holes thereof being illustrated in FIG. 4.
The configuration of the slot of the filament-forming hole of the spinneret represents an open tetragon 12 adjoining one of the sides whereof, i.e., the side opposite the open one, approximately in the mid-point thereof and at a right angle thereto, is the first rectilinear portion 13. This portion 13 is intersected approximately in the middle by a perpendicular section 14, whereby a cross-shaped element is formed. Therewith, the portion 13 adjoins, with its one end, the tetragon 12, the other end 13a being free. With the filament being formed through the spinneret with the spinning holes of such a configuration, the open tetragon 12 provides for an inner cavity in the filament extending along the entire length thereof. For the open contour to become continuous in the process of formation, the gap should constitute approximately from 1 to 5 slot widths. To obtain a desired size of the inner cavity, i.e., to provide for required thermal insulation properties of the filament, the ratio of the lengths of the sides of the tetragon 12 should range from 0.5 to 1, the sides being from 0.3 to 1.5 mm long. The ratio of the length of the rectilinear sections to the width of the slot is from 3 to 9, with the slot being 0.04 to 0.12 mm wide.
The cross-shaped element of the cross-sectional configuration provides for open capillary channels in the fibre. To ensure a required depth of the open capillary channels, i.e., to ensure necessary sorption properties, the length of the rectilinear portions (13) and (14) should range from 0.5 to 1.5 mm. Formation of the filament through the spinneret with such a configuration of the holes is carried out from molten polycaproamide having a relative viscosity of 2.4 and a temperature of 262° C. The temperature of the cooling air is 20° C., and the air feed velocity is 23 m/s. The rate of forming is 2,800 m/s; the draw ratio is 3.0. The temperature of the second stretch godets is 80° C. The cross-section of the filament is shown in FIG. 5. As a result of formation of the filament through the spinneret with such a configuration of the filament-forming hole, there may be obtained a filament with a cross-section composed of two elements, one of which, element "C", is cross-shaped, and the other element, "B", is shaped as a ring. Such a configuration of the cross-section provides for two deep open capillary channels ensuring adequate sorption properties of the filament, low heat conductivity and permanent crimp. Besides, the branch 15 in the shape of the filament cross-section formed by the free end 13a of the rectilinear portion 13 makes it possible to impart to the filament yarn composed of filaments of the given cross-sectional configuration increased bulk attained due to the greater interfilament spacing.
The physical and mechanical characteristics, sorption and thermal insulation properties of the formed wool-like filaments are indicated in Table 1, column 2.
EXAMPLE 3.
The polycaproamide wool-like filament is formed as described above through the spinneret 5 with the cross-section of one of the filament-forming holes as illustrated in FIG. 6. FIG. 6 shows the shape of the slot of the filament-forming hole, similar to that shown in FIG. 4, wherein adjoining the rectilinear section 14, at a right angle thereto and as close as possible to the ends thereof, are a second and third rectilinear portions 16 and 17 approximately equal in length and directed aside from the tetragon (12), whereby an element is formed shaped as a three-pronged fork. During formation of the filament, the open tetragon 12 ensures provision of an inner cavity as described above, whereas the element shaped as a three-pronged fork ensures sufficiently large and deep capillary channels, which is attainable with the size of the rectilinear portions 16 and 17 ranging from 0.25 to 0.60 mm.
Formation of the filament through the spinneret with such a configuration of the holes is accomplished from molten polycaproamide having a relative viscosity of 2.6 and a temperature of 265° C. The temperature of the cooling air is 23° C., the air feed velocity being 25 m/s. The rate of forming is 2700 m/min, and the draw ratio is 2.8. The second stretch godets are heated to 90° C.
As a result of formation of the filament through the spinneret with said filament-forming hole, there is obtained a filament with the configuration of its cross-section as shown in FIG. 7, composed of two elements "B" and "D". One of these elements, the element "D" is shaped as a three-pronged fork and the other, the element "B", is shaped as a ring. The presence in the configuration of the filament cross-section of the element "D" shaped as a three-pronged fork enables an increase in the moisture conductivity and capillarity of the filament due to the greater number of capillary channels and due to formation of two additional deep open capillary channels, four all in all. Besides, the element shaped as a three-pronged fork further increases the bulk of the filament yarn composed of filaments with the above configuration of the cross-section due to greater interfilament distances. The physical and mechanical properties of the formed filament are indicated in Table 1, column 3.
EXAMPLE 4
Formation of the polycaproamide wool-like filament is accomplished, as described above, through the spinneret 5 with the cross-section of one of the filament-forming holes as shown in FIG. 8.
The configuration of the filament-forming hole in the spinneret represents a tetragon 12 open at one of its vertices, the rectilinear portion 13 of the element shaped as a three-pronged fork similar to that shown in FIG. 6, adjoining the vertex "E" of the tetragon. Emerging from the same vertex "E" of the tetragon 12 is one more, fourth rectilinear portion 18 perpendicular to the first portion 13. The open tetragon with a gap equalling approximately 1 to 5 widths of the slot has a ratio of the lengths of the short and long sides ranging from 0.6 to 1.0, the sides of the polygon being approximately two times shorter as compared with the polygon in the holes shown in FIGS. 2, 4 and 6. The ratio of the lengths of the portions 13, 14 and 18 to the length of the side of the tetragon 12 adjoined by the three-pronged fork is, respectively, 1 to 1.4, 1.2 to 1.8 and 0.5 to 0.9.
Formation of the filament through the spinneret with such a configuration of the holes is accomplished from molten polycaproamide having a relative viscosity of 2.65 and a temperature of 267° C. The temperature of the cooling air is 24° C., the air being fed at 27 m/s. The rate of forming is 2,900 m/min, the draw ratio is 2.9, with the temperature of the second stretch godets being equal to 110° C.
As a result of formation of the filament through such a filament-forming hole in the spinneret, there is obtained a filament with the configuration of the cross-section as shown in FIG. 9, composed of the following elements: the element "D" shaped as a three-pronged fork, an additional branch 19 formed by the additional rectilinear portion 18 emerging from the vertex "E" of the tetragon 12, and the ring-shaped element "B". In this case, as distinct from the above-considered cross-sections of the filament, the ring-shaped element "B" is approximately twice as small.
Besides, the ring-shaped element "B" in the cross-section of the filament occupies the right upper corner relative to the axis of symmetry of the contour. The three-pronged element "D", along with the additional rectilinear branch 19 and the ring-shaped element "B", form four deep open capillary channels. In addition, intermediate of the additional branch 19 and the ring-shaped element "B" in the cross-section, there if formed one more less deep capillary channel. The presence of the latter improves the sorption properties of the filament. The smaller size of the cavity and the circumferential arrangement thereof with respect to the axis of symmetry of the configuration of the cross-section change the filament cooling conditions and ensure fine crimp of the filament, which is desirable for the production of a filament yarn of low linear density suitable for manufacture of light fabric of adequate hygienic properties to be used in hot and humid climates.
The physical and mechanical properties of the formed filament are indicated in Table 1, column 4.
EXAMPLE 5
Formation of the polycaproamide wool-like filament is carried out, as described above, through the spinneret 5 with the cross-section of one of the filament-forming holes as shown in FIG. 10.
The configuration of the filament-forming hole in the spinneret is similar to that shown in FIG. 8. Adjoining the fourth rectilinear portion 18, at a right angle thereto, is a fifth rectilinear portion 20. Arranged at the free end of the fifth rectilinear portion 20, at a right angle thereto, is another, sixth rectilinear portion 21 directed to the tetragon 12, whereby there is formed an additional open polygon 22 approximately equal in size to the polygon 12. The ratio of the lengths of the portions 20 and 21 to the length of the portion 18 is 1.1 to 1.3 and 0.5 to 0.8. The sides of the polygon 22 are approximately two times shorter than the sides of the tetragon 12, as shown in FIGS. 2, 4 and 6.
Formation of the filament through the spinneret with such a configuration of the holes is performed from molten polycaproamide having a relative viscosity of 2.64 and a temperature of 268° C. The temperature of the cooling air is 19° C., the air is fed at a rate of 28 m/s. The rate of forming is 3,100 m/min, the draw ratio is 2.5, the temperature of the second stretch godets being 125° C.
As a result of formation of the filament through such a hole in the spinneret, the obtained filament has, as is shown in FIG. 11, two closed ring-shaped elements "B" and "F" which form two small cavities in the filament, and the three-pronged element "D" which forms in the filament four deep open capillary channels. The produced filament yarn features high stiffness and resilience. The filament yarn composed of filaments with the given cross-sectional shape may be used for the production of pile fabrics with pile resistant to mechanical action. The physical and mechanical properties of the formed filament are indicated in Table 1, column 5.
EXAMPLE 6
Formation of the polycaproamide wool-like filament is carried out, as described above, through the spinneret 5 with the cross-section of one of the filament-forming holes as shown in FIG. 12.
The configuration of the filament-forming hole is similar to that shown in FIG. 10. The rectilinear portion 13 with which the three-pronged fork adjoins the tetragon 12 is intersected approximately in the middle by a perpendicular seventh portion 23. The ratio of the length of the portion 23 to the length of the portion 13 is 1.3 to 2.
Formation of the filament through the spinneret with such a configuration of the holes is performed from molten polycaproamide having a relative viscosity of 2.68 and a temperature of 270° C. The temperature of the cooling air is 19° C., the air feed velocity being 29 m/s. The rate of forming is 3,200 m/min, the draw ratio is 2.55, and the temperature of the second stretch godets is 135° C.
As a result of formation through such a hole, the filament cross-section, as is shown in FIG. 13, is composed of the following elements: two ring-shaped elements "B" and "F", the element "D" shaped as a three-pronged fork and two additional rectilinear branches 24 and 25. Two ring-shaped elements "B" and "F" form two cavities in the filament, identical in size with those formed in the filament whose cross-section is shown in FIGS. 11 and 9. The element "D" shaped as a three-pronged fork and two additional branches 24 and 25, together with the ring-shaped elements, form six deep open capillary channels. Besides, the two additional branches 24 and 25 equalize the masses of two portions of the filament cross-section, one of which includes the element "D" shaped as a three-pronged fork and two additional rectilinear branches 24 and 25 and the other, two ring-shaped elements "B" and "F".
This decreases somewhat the filament crimp. However, due to the increased number of the deep open capillary channels, the sorption properties are markedly improved. The latter ensures adequate ventilation of the space between the human body and the garment. The physical and mechanical properties of the formed filament are indicated in Table 1, column 6.
EXAMPLE 7
Formation of the polycaproamide wool-like filament is accomplished, as described above, through the spinneret 5 with the cross-section of one of the filament-forming holes as shown in FIG. 14. The configuration of the filament-forming hole in the spinneret represents an open tetragon 12 identical with that shown in FIG. 8. Adjoining one of the vertices "E" of this tetragon is an element shaped as a two-pronged fork formed by the portions 13, 16, 17 and 14.
Emerging from the same vertex "E" of the tetragon 12 is a fourth rectilinear portion 18 perpendicular to said first portion 13 which is intersected roughly in the middle and at a right angle by the rectilinear portion 23. Therewith, the sizes of said portions and the ratios thereof are similar to the sizes of the like portions in the cross-sections shown in FIGS. 8, 10, 12. Formation of the filament through the spinneret with such a configuration of the holes is performed from molten polycaproamide having a relative viscosity of 2.72 and the temperature of 275° C. The temperature of the cooling air is 19° C., the air feed velocity is 33 m/s. The rate of forming is 3,500 m/min, the draw ratio is 2.6 and the temperature of the second stretch godets is 150° C.
As a result of formation through such a hole, the cross-section of the filament, as is shown in FIG. 15, is composed of: an element "G" shaped as a two-pronged fork, three rectilinear branches 24, 25 and 19, and a ring-shaped element "B". The ring-shaped element "B" forms in the filament a cavity similar in size to that in the filament whose cross-section is shown in FIG. 9 and which is arranged circumferentially relative to the axis of symmetry of the contour. At the same time, the rectilinear branches 24, 25, 19 and the element shaped as a two-pronged fork form, together and along with the ring-shaped element, five deep open capillary channels and one less deep capillary channel formed by the branch 19 along with the element "B".
Due to the plurality of capillary channels and also due to the small cavity, such a filament features high sorption properties and fine crimp and may be used in light fabrics and knitwear suitable for hot and humid climates.
As is seen from Table 1, the filament yarn composed of filaments obtained on the spinneret with the proposed shapes of the spinning holes possesses all wool-like properties, namely, low heat conductivity, permanent crimp and high hygienic properties.
Table 1__________________________________________________________________________ Caprone filamen- WoolCharacteristics 1 2 3 4 5 6 7 tary yarn yarn__________________________________________________________________________ Linear density, tex 15.7 15.7 15.7 15.7 15.7 15.7 15.7 15.6 17.8 Number of filaments in the filament yarn 45 45 45 45 45 45 45 45 Relative strength, N/tex 0.40 0.41 0.39 0.43 0.42 0.43 0.42 0.41 0.26 Relative breaking elonga- tion, % 26.3 26.7 26.8 26.7 27.9 27.1 25.7 28.2 14.4 Sorption properties:capillarity, mm 54 57 60 64 59 70 66 28 25moisture absorption, % 74 76 84 90 85 96 93 42 96moisture desorption, % 30 34 39 44 40 45 45 18 Conductivity factor, W/m . °K. 0.040 0.040 0.038 0.042 0.041 0.038 0.043 0.049 0.040 Crimpcrimps per cm 2-5 2-6 2-8 2-10 2-7 2-8 2-10 no crimp 5-12 Unity of modulus, Pa 2.0 · 10.sup.7 2.2 · 10.sup.7 2.1 · 10.sup.7 2.4 · 10.sup.7 2.3 · 10.sup.7 2.2 · 2.4 · 10.sup.7 2.1 · 10.sup.7 0.76-10.sup.7 · 10.sup.7 Stiffness in twisting, rel. units 118 119 122 123 125 124 123 109 9210. Complete deformation, % 4.8 5.3 6.2 4.9 6.4 5.7 5.9 5.5 2.2 Component recovered deformation 0.92 0.93 0.93 0.95 0.97 0.95 0.98 0.97 0.69 Specific strength, %knot strength 97 99 98 98 97 93 96 98 96loop break strength 99 99 97 99 98 94 97 95 87 Fatigue life, thousands of cycles >30 >30 >30 >30 >30 >30 >30 >30 0.25 Double flexing life, thousands of cycles >50 >50 >50 >50 >50 >50 >50 >50 25.2 Resistance to abrasion, thousands of cycles 43 48 51 59 47 52 55 48 1.9 Boiling water shrinkage, % 14.8 14.7 13.8 15.5 15.6 14.9 15.1 11.2 5.4__________________________________________________________________________
EXAMPLE 8
The filament yarn composed of filaments formed on the spinneret with the proposed spinning holes is subjected to twisting ranging from 10 to 1,500 T.P.M. Said twist is imparted to the filament yarn with the aim of improving the wool-like properties of the yarn and the textile product therefrom.
An excessively high twist results in an overtight yarn possessing increased heat conductivity, the decreased bulk of the yarn resulting in increased stiffness thereof.
Too low a twist impairs the sorption properties of the yarn and the product therefrom.
The physical and mechanical properties of the filament wool-like yarn with various amounts of twist applied thereto are given in Table 2.
Table 2__________________________________________________________________________ SamplesCharacteristics 1 2 3 4__________________________________________________________________________ Twist range, T.P.M. 10 500 1000 1500 Relative strength, N/tex 0.43 0.45 0.44 0.39 Breaking elongation, % 26.7 28.6 29.3 33.1 Complete deformation, % 5.1 5.8 6.7 7.2 Component recovered 0.92 0.94 0.97 0.97 deformation Stiffness in twisting, 101 110 111 118 rel, units Static electricity, C/m 11.6 × 11.4 × 10.3 × 10.5 × 10- 10-10 10-10 × 10-10 -10 Conductivity factor, 0.042 0.045 0.049 0.050 W/m . °K. Capillarity, mm 56 58 60 6310. Diameter, mm 0.35 0.29 0.26 0.23__________________________________________________________________________
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The present invention relates to production of wool-like chemical filaments and, more particularly, to a spinneret for obtaining these filaments. The present invention is most effectively realized in the production from these filaments of household and industrial textiles. This spinneret includes a filament-forming hole made as a slot with a configuration of an open polygon, having a rectilinear portion adjoining one of the sides thereof and one more element shaped as a rectilinear section adjoining this portion at a right angle thereto. Such a structure of the spinneret permits production of a wool-like filament possessing all properties inherent in natural wool, namely, low heat conductivity, permanent crimp, and high hygienic properties.
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This application is a continuation of application Ser. No. 306,965, filed Sept. 30, 1981 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to new and useful acid-curing resin compositions for use in the formation of sand cores and molds for foundry operations and to new di-esters of lower aliphatic dibasic acids.
2. Description of the Prior Art
In the foundry industry, sand is coated with resin binders and formed into molds and cores for the production of precision castings. A wide variety of techniques have been developed for the manufacture of sand cores and molds. These involve the hot box technique for mold and core formation; the shell method; the "No-Bake", and the cold-box technique.
In the hot box and shell methods, sand molds and cores are formed by heating a mixture of sand and a thermosetting resin at a temperature of about 300°-600° F. in contact with patterns which produce the desired shape for the mold or core. The resin is polymerized and a core or mold is formed. Procedures of this type are described in Dunn U.S. Pat. No. 3,059,297 and Brown U.S. Pat. No. 3,020,609.
A particular disadvantage of the hot box and shell methods is the necessity for heating the pattern boxes to 300°-600° F. to polymerize and cure the resin binder. This involves considerable expense and is generally a high cost technique.
The cold box techniques for core and mold formation involve the use of sand mixed or coated with resins which may be cured at room temperature by acid or base catalysis. Acidic or basic catalysts have been used in liquid, solid or gaseous form. Typical cold box processes are shown in Blaies U.S. Pat. No. 3,008,205; Dunn U.S. Pat. No. 3,059,297; Peters U.S. Pat. No. 3,108,340; Kottke U.S. Pat. No. 3,145,438; Brown U.S. Pat. No. 3,184,814; Robins U.S. Pat. No. 3,639,654; Australian Pat. No. 453,160 and British Pat. No. 1,225,984. Many of these processes involve the use of sulfur-containing acid catalysts such as benzene sulfonic acid, toluene sulfonic acid and the like. Richard U.S. Pat. No. 3,879,339 discloses coating sand with an organic peroxide and resin, forming into a mold or core and gassing with sulfur dioxide.
A number of U.S. and foreign patents disclose the use of furfuryl alcohol and other furfuryl-substituted compounds in resin polymerization and also the use of dibasic acids and some esters in resin compositions.
Bradley U.S. Pat. No. 2,238,030 discloses the use of di-alkenyl esters of dibasic acids in the copolymerization of addition polymers.
Dannenberg U.S. Pat. No. 2,650,211 discloses polymers including dibasic acids as precursors.
Treat U.S. Pat. No. 2,999,829 discloses the copolymerization of furfuryl alcohol and maleic anhydride in the prepatatio of foundry cores.
Case U.S. Pat. No. 3,312,650 resins bases on phenol and furfuryl alcohol modified with formaldehyde and treated with an acid catalyst.
Kirkpatrick U.S. Pat. No. 3,244,770 discloses the use of di-esters of dibasic acids in phenolic resin compositions.
Bean U.S. Pat. No. 3,248,276 discloses the use of dibasic acids in resin compositions containing condensation-type resins.
Guyer U.S. Pat. No.3,404,118 discloses the use of furfuryl glycidyl ether in molding resins.
Fitko U.S. Pat. No. 3,600,290 discloses the use of unsaturated esters in resin compositions.
Adkins U.S. Pat. No. 3,725,333 discloses the preparation of foundry molds, etc. using phenolic resins modified with furfuryl alcohol.
Laitar U.S. Pat. No. 4,051,301 discloses resins for sand cores or molds by incorporating furan into a furfuryl alcohol-modifed phenolic resin prepolymer.
Anderson U.S. Pat. No. 4,083,817 discloses the acid curing of mixtures of furan-formaldehyde resins with phenolic resins for production of foundry cores and molds.
British Pat. Nos. 626,763 and 992,345 disclose the use of glyceryl esters and other esters of aliphatic dibasic acids in condensation polymers.
The bis(tetrahydrofurfuryl) ester of adipic acid is known but does not undergo condensation type polymerization.
The above noted patents, however, do not consider the problem of the preferential polymerization of furfuryl alcohol when admixed with phenolic and other condensation-type resins and the problem of short bench life, or any way to overcome these problems.
SUMMARY OF THE INVENTION
It is one object of the invention to provide a solution to some of the aformentioned problems and provide resins having a more useful bench life and produce cores and molds having greater strength and hardness.
Another object of the invention is to provide resin compositions having the properties and desires characteristics of furfuryl alcohol-containing resins without the problems of short bench life and working time.
Another object of the invention is to provide a novel class of compounds which is useful in modifying condensation-type resins.
Other objects of the invention will become apparent from time to time throughout the specification and claims as hereinafter related.
The above stated objects and other apparent objects of the invention ase accomplished by novel resin compositions comprising acid-curable, condensation-type resins, particularly phenolic resin prepolymers and urea-formaldehyde and/or furfuryl alcohol formaldehyde modified phenolic resin prepolymers admixed with a dibasic acid di-ester of the composition
R.sup.1 O.sub.2 C(CH.sub.2).sub.n CO.sub.2 R.sup.2
where n is from 1 to 8, R 1 is furfuryl, and R 2 is furfuryl or methyl. The di-esters are preferably added in the amount of 5-35%, by weight of total composition. These compositions are particularly useful in the preparation of sand cores and molds for foundry use which have improved strength and hardness.
The dibasic acid di-esters of the composition
R.sup.1 O.sub.2 C(CH.sub.2).sub.n CO.sub.2 R.sup.2
where n is from 1 to 8, R 1 is furfuryl, and R 2 is furfuryl or methyl are not reported in the literature and are novel compounds. These di-esters are oily liquids having high boiling points and are particularly useful as resin modifiers, diluents and plasticizers. These di-esters are produced by the sodium-catalyzed transesterification reaction of furfuryl alcohol with the liquid dimethyl esters of the C 3 -C 10 linear aliphatic dibasic acids at temperatures of about 214°-240° F.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As noted above, the use of furfuryl alcohol modified resins is well reported in the prior art. The prior art, however, does not treat the problem of preferential polymerization of furfuryl alcohol when admixed with phenolic and other resins or suggest any solution to the problem. In this invention, it has been discovered that a novel class of esters, viz. the furfuryl-methyl esters or the difurfuryl esters of C 3 -C 10 linear aliphatic dibasic acids may be mixed with phenolic resin prepolymers (and other condensation-type resins) and copolymerized by acid catalysis uniformly. The use of these resin compositions in the preparation of foundry cores and molds results in easier handling of the resins and the sand-resin compositions and improved foundry cores and molds, both in tensile strength and hardness.
The preparation of the novel esters and their properties and use in resin compositions will be discussed separately below.
PREPARATION AND PROPERTIES OF FURFURYL DI-ESTERS
The difurfuryl esters and mixed methyl-furfuryl esters of aliphatic dibasic acids are prepared by a sodium-catalyzed transesterification of the corresponding dimethyl esters.
EXAMPLE I
Preparation of Difurfuryl Glutarate
Furfuryl alcohol is a moderately high boiling liquid, b.p. 340° F. Dimethyl glutarate is a very high boiling liquid, b.p. 417° F.
196 parts by wt. of furfuryl alcohol and 160 parts by wt. dimethyl glutarate (stoichiometric proportions) were mixed and 0.5-0.75% wt. sodium metal added. The mixture was heated to a temperature in the range from 214°-240° F. under a nitrogen atmoshpere. Methanol was evolved and removed as the reaction progressed. After a period of 4 hours, a waxy solid was obtained. After washing the product with water, the residure was a liquid which was identified as difurfuryl glutarate by gas chromatography and mass spectrometric analysis.
Additional runs established that the mixed methyl-furfuryl ester of glutaric acid is obtained when the reaction is not run long enough and does not go to completion. When the reaction is carrier out with a stoichiometric excess of furfuryl alcohol, e.g. 2:1 mol ratio, the reaction goes to completion sooner but the excess furfuryl alcohol must be separated from the product. It has also been found that when the reaction temperature is allowed to go too high, there is some decomposition and an appreciable amount of difurfuryl succinate is produced.
EXAMPLE II
Preparation of Difurfuryl Succinate
Furfuryl alcohol is a moderately high boiling liquid, b.p. 340° F. Dimethyl succinate is a very high boiling liquid, b.p. 385° F.
196 parts by wt. of furfuryl alcohol and 146 parts by wt. dimethyl glutarate (stoichiometric proportions) were mixed and 0.5-0.75% wt. sodium metal added. The mixture was heated to a temperature in the range from 214°-240° F. under a nitrogen atmoshpere. Methanol was evolved and removed as the reaction progressed. After a period of 4 hours, a waxy solid was obtained. After washing with water, a liquid residue was obtained which product was identified as difurfuryl succinate.
Additional runs established that the mixed methyl-furfuryl ester of succinic acid is obtained when the reaction is not run long enough and does not go to completion. It has also been found that when the reaction temperature is allowed to go too high, there is some decomposition and an appreciable amount of difurfuryl malonate is produced.
EXAMPLE III
Preparation of Difurfuryl Adipate
Furfuryl alcohol is a moderately high boiling liquid, b.p. 340° F. Dimethyl adipate is a very high boiling liquid, b.p. 235° F., at 13 mm.
196 parts by wt. of furfuryl alcohol and 174 parts by wt. dimethyl adipate (stoichiometric proportions) were mixed and 0.5-0.75% wt. sodium metal added. The mixture was heated to a temperature in the range from 214°-240° F. under a nitrogen atmoshpere. Methanol was evolved and removed as the reaction progressed. After a period of 4 hours, a waxy solid was obtained. After washing with water, a liquid residue was obtained which product was identified as difurfuryl adipate.
Additional runs established that the mixed methyl-furfuryl ester of adipic acid is obtained when the reaction is not run long enough and does not go to completion. It has also been found that when the reaction temperature is allowed to go too high, there is some decomposition and an appreciable amount of difurfuryl glutarate is produced.
EXAMPLE IV
Preparation of Difurfuryl Malonate
Furfuryl alcohol is a moderately high boiling liquid, b.p. 340° F. Dimethyl malonate is a very high boiling liquid, b.p. 361° F.
196 parts by wt. of furfuryl alcohol and 132 parts by wt. dimethyl malonate (stoichiometric proportions) are mixed and 0.5-0.75% wt. sodium metal added. The mixture is heated to a temperature in the range from 214°-240° F. under a nitrogen atmoshpere. Methanol is evolved and removed as the reaction progressed. After a period of 4 hours, a waxy solid is obtained. The liquid product obtained after washing with water is difurfuryl malonate.
The mixed methyl-furfuryl ester of malonic acid is obtained when the reaction is not run long enough and does not go to completion. When the reaction temperature is allowed to go too high, there is some decomposition which gives an unsatisfactory result.
EXAMPLE V
Preparation of Other Difurfuryl Esters
Furfuryl alcohol is a moderately high boiling liquid, b.p. 340° F. The dimethyl esters of other lower aliphatic acids are prepared by the same transesterification reaction. Dimethyl pimelate is a very high boiling liquid, b.p. 248° F. at 10 mm. Dimethyl suberate is a still higher boiling liquid, b.p. 514° F. Dimethyl azelate boils at 313° F. at 20 mm. Dimethyl sebacate boils at 144° F. at 5 mm. These esters are well known high-boiling oleagenous liquids which have had some use as synthetic lubricants.
When furfuryl alcohol and any of the above listed dimethyl esters are mixed in stoichiometric proportions and 0.5-0.75% wt. sodium metal added and the mixture heated to a temperature in the range from 214°-240° F. under a nitrogen atmoshpere, the reaction proceeds as described above for the other esters. Methanol is evolved and removed as the reaction progresses. After a period of 4 hours, a waxy solid is obtained in each case. Water washing any of these products to remove impurities leaves a liquid residue which is a difurfuryl esters of the respective acids.
The mixed methyl-furfuryl esters are obtained when the reaction is not run long enough and does not go to completion. It has also been found that when the reaction temperature is allowed to go too high, there is some decomposition and some difurfuryl esters of the lower dibasic acids are obtained.
When the reaction is carried out using mixtures of the dimethyl esters of various C 3 -C 10 aliphatic dibasic acids in the transesterification reaction, the difurfuryl ester (or the mixed methyl-furfuryl esters) of the various acids are produced.
USES OF FURFURYL DI-ESTER/RESIN MIXTURES
The difurfuryl esters and the mixed methyl furfuryl esters of the dibasic acids described above are compatible extenders for various condensation-type resins.
PHENOLIC RESIN COMPOSITIONS WITH DIFURFURYL GLUTARATE
EXAMPLE VI
A molding resin composition was prepared by mixing 20% wt. of liquid difurfuryl glutarate with 80% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand was then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 80/20 resin-ester mixture was added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture was formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 78 minutes at about 78° F.
The test biscuits have a tensile strength of 196 lbs. after 24 hrs. as compared with a tensile strength of 161 lbs. for a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl glutarate ester.
Other catalysts can be used in forming the test biscuits which are customarily used in curing sand cores and molds. The aromatic sulfonic acids, including benzene sulfonic acid, toluene sulfonic acid, xylene sulfonic acid, and mixtures thereof, either alone or diluted with water and/or methanol or other diluents. Sometimes fluoboric acid or sulfuric acid may be added.
EXAMPLE VII
A molding resin composition is prepared by mixing 35% wt. of liquid difurfuryl glutarate with 65% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 65/35 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 80 minutes at about 76° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. The tensile strength is somewhat less than in Example VI but is substantially better than the control. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl glutarate ester.
When larger amounts of the ester are used, e.g. 40% and higher, the test results are poorer than the controls. Likewise, when lesser proportions of the ester are used, down to 5%, results are obtained which are better than the controls. While the range of 5-35% of the difurfuryl esters is preferred, a much wider range may be used where the desired function is that of a diluent or plasticizer in the ester/resin composition.
Other catalysts can be used in forming the test biscuits which are customarily used in curing sand cores and molds. The aromatic sulfonic acids, including benzene sulfonic acid, toluene sulfonic acid, xylene sulfonic acid, and mixtures thereof, either alone or diluted with water and/or methanol or other diluents. Sometimes fluoboric acid or sulfuric acid may be added.
MODIFIED RESIN COMPOSITIONS
EXAMPLE VIII
A molding resin composition is prepared by mixing 25% wt. of liquid difurfuryl glutarate with 75% wt. of a furan modified phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a toluene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 75/25 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 85 minutes at about 75° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same furan modified phenolic resin prepolymer without the difurfuryl ester. The tensile strength is somewhat less than in Example VI but is substantially better than the control. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl glutarate ester.
Other catalysts can be used in forming the test biscuits which are customarily used in curing sand cores and molds, as noted in Examples VI and VII.
SULFUR DIOXIDE CURING OF RESINS CONTAINING ESTERS
EXAMPLE IX
A molding resin composition was prepared by mixing 20% wt. of liquid difurfuryl glutarate with 80% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with about 0.5% methyl ethyl ketone peroxide as a catalyst precursor. Then, 1.25%, by weight of the sand, of 80/20 resin-ester mixture is added to the sand and peroxide and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and gassed with sulfur dioxide for about 0.5-5 seconds at a temperature of from room temperature to 85°-90° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester, and also better than a furan modified phenolic resin having about the same furfuryl content.
SULFUR DIOXIDE CURING MODIFIED RESIN
EXAMPLE X
A molding resin composition was prepared by mixing 20% wt. of liquid difurfuryl glutarate with 80% wt. of a urea-formaldehyde/furan-modified phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with about 0.6% methyl ethyl ketone peroxide as a catalyst precursor. Then, 1.25%, by weight of the sand, of 80/20 resin-ester mixture is added to the sand and peroxide and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and gassed with sulfur dioxide for about 0.5-5 seconds at a temperature of 80°-85° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same resin prepolymer without the difurfuryl ester.
EXAMPLE XI
A molding resin composition was prepared by mixing 20% wt. of liquid difurfuryl glutarate with 80% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand was then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 80/20 resin-ester mixture was added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture was formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 78 minuts at about 78° F.
The test biscuits have a tensile strength of 196 lbs. after 24 hrs. as compared with a tensile strength of 161 lbs. for a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl glutarate ester.
Other catalysts may be used with this resin composition, particularly those discussed in Examples VI and VII, above.
RESINS CONTAINING DIFURFURYL ADIPATE
EXAMPLE XII
A molding resin composition is prepared by mixing 30% wt. of liquid difurfuryl adipate with 70% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 70/30 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 80 minutes at about 76° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl adipate ester.
Other catalysts may be used with this resin composition, particularly those discussed in Examples VI and VII, above.
RESINS CONTAINING DIFURFURYL SUCCINATE
EXAMPLE XIII
A molding resin composition is prepared by mixing 20% wt. of liquid difurfuryl succinate with 80% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 80/20 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 72 minutes at about 79° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl succinate ester.
Other catalysts may be used with this resin composition, particularly those discussed in Examples VI and VII, above.
RESINS CONTAINING MIXED DIFURFURYL ESTERS
EXAMPLE XIV
A molding resin composition was prepared by mixing 20% wt. of liquid difurfuryl esters of a mixture of glutaric, succinic and adipic acids with 80% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand was then mixed with a benzene sufonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 80/20 resin-ester mixture was added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture was formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 80 minutes at about 75° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl esters. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl mixed acid esters.
Other catalysts may be used with this resin composition, particularly those discussed in Examples VI and VII, above.
RESINS CONTAINING DIFURFURYL MALONATE
EXAMPLE XV
A molding resin composition Is prepared by mixing 25% wt. of liquid difurfuryl malonate with 75% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 75/25 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 74 minutes at about 78° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl malonate ester.
Other catalysts may be used with this resin composition, particularly those discussed in Examples VI and VII, above.
RESINS CONTAINING DIFURFURYL PIMELATE
EXAMPLE XVI
A molding resin composition is prepared by mixing 15% wt. of liquid difurfuryl pimelate with 85% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 85/15 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 74 minutes at about 80° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl pimelate ester.
Other catalysts may be used with this resin composition, particularly those discussed in Examples VI and VII, above.
RESINS CONTAINING DIFURFURYL SUBERATE
EXAMPLE XVII
A molding resin composition is prepared by mixing 20% wt. of liquid difurfuryl suberate with 80% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 80/20 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 70 minutes at about 82° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl suberate ester.
Other catalysts may be used with this resin composition, particularly those discussed in Examples VI and VII, above,
RESINS CONTAININE DIFURFURYL AZELATE
EXAMPLE XVIII
A molding resin composition is prepared by mixing 35% wt. of liquid difurfuryl azelate with 65% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 65/36 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 78 minutes at about 78° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl azelate ester.
Other catalyst may be used with this resin composition, particularly those discussed in Examples VI and VII, above.
RESINS CONTAINING DIFURFURYL SEBACATE
EXAMPLE XIX
A molding resin composition is prepared by mixing 20% wt. of liquid difurfuryl sebacate with 80% wt. of a phenol formaldehyde resin prepolymer.
A foundry-grade sand is then mixed with a benzene sulfonic acid catalyst in the amount of 45% by weight of the resin composition to be added. Then, 1.25%, by weight of the sand, of 80/20 resin-ester mixture is added to the sand and catalyst and thoroughly mixed.
The resin composition-sand mixture is formed into test biscuits, simulating a foundry core or mold, and allowed to cure for 78 minutes at about 78° F.
The test biscuits have a tensile strengths after 24 hrs. which are better than the tensile strength of a control produced under the same conditions using the same phenolic resin prepolymer without the difurfuryl ester. Substantially the same results are obtained using slightly greater amounts of the mixed methyl-furfuryl sebacate ester.
Other catalysts may be used with this resin composition, particularly those discussed in Examples VI and VII, above.
While this invention has been described fully and completely with special emphasis upon several preferred embodiments, it should be understood that within the scope of the appended claims this invention may be practiced otherwise than as specifically described herein.
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Acid-curable, condensation-type resins, particularly phenolic resin prepolymers and urea-formaldehyde and/or furfuryl alcohol-formaldehyde modified phenolic resin prepolymers, have improved properties when admixed with a dibasic acid di-ester of the composition
R.sup.1 O.sub.2 C(CH.sub.2).sub.n CO.sub.2 R.sup.2
where n is from 1 to 8, R 1 is furfuryl, and R 2 is furfuryl or methyl. The di-esters are preferably added in the amount of 5-35%, by weight of total composition. These compositions are particularly useful in the preparation of sand cores and molds for foundry use which have improved strength and hardness.
The dibasic acid di-esters of the composition
R.sup.1 O.sub.2 C(CH.sub.2).sub.n CO.sub.2 R.sup.2
where n is from 1 to 8, R 1 is furfuryl, and R 2 is furfuryl or methyl are not reported in the literature and are novel compounds. These di-esters are oily liquids having high boiling points and are particulary useful as resin modifiers, diluents and plasticizers. These di-esters are produced by the sodium-catalyzed transesterification reaction of furfuryl alcohol with the liquid dimethyl esters of the C 3 -C 10 linear aliphatic dibasic acids at temperatures of about 214°-240° F.
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RELATED APPLICATIONS
[0001] This application is a continuing application of U.S. patent application Ser. No. 09/148,182, filed Sep. 4, 1998 (Case No. 2049), and U.S. patent application Ser. No. 09/400,511, filed Sep. 20, 1999 (Case No. 2097), the contents of which are incorporated herein in their entirety.
FIELD OF THE INVENTION
[0002] This invention relates to metallized fabrics which are durable to washing and wear. They can be used to down-proof articles in which they are used as linings, e.g., down and fiber filled, insulated articles of clothing and sleeping bags.
BACKGROUND OF THE INVENTION
[0003] Metallized fabrics are utilized to reflect radiant heat emitted by the body and thus provide effective heat insulation, particularly for outdoor use and in cold weather climates, e.g., winter apparel and sleeping bags.
[0004] U.S. Pat. No. 4,569,874 to Kuznetz discloses lightweight sportswear fabric for cold climates which comprises a composite fabric having vapor-permeable laminate formed by a core layer of hollow fibers acting as a thermal blanket between inner and outer skins. Both faces of the inner skin and the inside face of the outer skin are metallized to render them reflective while the outside face of the outer skin is blackened to absorb solar energy. Radiant heat from the wearer is reflected by the outside face of the inner skin while convection heat from the wearer's body passes by conduction through the inner skin of the laminate to be absorbed by the core layer. Solar heat absorbed by the blackened face is conducted through the outer skin to be absorbed by the core layer. Infrared energy loss from the core layer is minimized by internal reflection from the reflective inside faces of the skins.
[0005] U.S. Pat. No. 5,750,242 to Culler discloses a fabric which provides thermal image masking in mid and far infra-red region without compromising the effectiveness of visual and near IR camouflage or comfort level. The material incorporates a metallized microporous membrane into a typical article of clothing or covering, e.g., tents, which suppresses thermal imaging. An air permeable, moisture vapor transmitting, waterproof material having a metallized membrane is laminated to a textile backing and the metal in the metallized membrane forms a discontinuous layer at the surface and on the pore walls adjacent the surface of the microporous membrane. This provides an air permeable, vapor transmissive, waterproof material which suppresses thermal imaging of objects behind the metallized membrane.
[0006] U.S. Pat. No. 5,271,998 to Duckett discloses a lightweight metallized fabric which can be used in an automobile cover. The fabric is made by vacuum metallizing with aluminum and applying a finishing solution comprising a urethane, acrylic, fluorocarbon polymer emulsion, drying the fabric at 320° to 400° F. and optionally calendering the fabric after drying.
[0007] U.S. patent application Ser. No. 09/148,182, filed Sep. 4, 1998, (Case No. 2049) discloses a metallized fabric of improved washfastness which comprises discrete metal particles encapsulated within a cross-linked polyurethane latex. U.S. patent application Ser. No. 09/400,511, filed Sep. 20, 1999, (Case No. 2097) discloses a metallized fabric of improved washfastness which comprises discrete metal particles encapsulated within a cross-linked polyurethane latex, wherein the metal particles are treated with a primer coating composition comprising the reaction product of a copolymer comprising at least two different monomers: (i) a phosphate-containing vinyl monomer and (ii) a second, separate vinylic monomer containing at least one reactive group capable of covalently reacting with the cross-linking agent present within the polyurethane latex coating.
[0008] It would be desirable to provide insulated metallized fabric articles suited to use in cold weather applications such as insulated apparel, sleeping bags, etc. which comprise a fabric having a metal-coated side and an uncoated side which fabric is of improved washfastness. Moreover, it would be desirable to provide metallized fabric articles that do not allow the migration of natural and synthetic insulations, such as hollow fibers or down, through the fabric so as to contain the insulation within the article during normal use and washing.
SUMMARY OF THE INVENTION
[0009] In one aspect, the present invention relates to a durable, lightweight metallized fabric which can be used as a lining for insulated articles and which is resistant to migration of insulating materials through its thickness. The fabric comprises: a metallic side having a metal coating containing discrete metal particles, a non-metallic side, and a cross-linked polyurethane latex coating over both sides which encapsulates said metal particles. The fabric can be calendered to an extent sufficient to reduce migration of insulation through its thickness.
[0010] In another aspect, the present invention relates to a method of preparing a metallized fabric which comprises
[0011] i) providing a fabric,
[0012] ii) coating one side of said fabric with metal particles,
[0013] iii) coating both sides of said fabric in a cross-linked polyurethane latex comprising a polyurethane dispersion, a cross-linking agent, an inhibitor, and optionally, a catalyst to initiate cross-linking of said polyurethane dispersion, to encapsulate said metal particles within said polyurethane latex; and
[0014] iv) calendering said fabric to an extent sufficient to reduce migration of insulation through its thickness.
[0015] In yet another aspect, the present invention relates to an article of clothing containing insulation and having an interior lining of metallized fabric resistant to passage of said insulation through its thickness, which comprises a metallic side coated with metal particles, a non-metallic side, and a cross-linked polyurethane latex coating over both sides to encapsulate said metal particles within said polyurethane latex, wherein the metallic side faces a body surface of a wearer. The resistance of the fabric to passage of the insulation can be increased by calendering the metallized fabric.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Without limiting the scope of the invention, the preferred embodiments and features are hereinafter set forth.
[0017] The present invention relates to a metallized fabric of improved washfastness which comprises a metallic side, a non-metallic side and a cross-linked polyurethane latex coating on both sides. The metallic side comprises a metal coating containing discrete metal particles encapsulated within the cross-linked polyurethane latex. The encapsulated metal coating serves to resist corrosion of the metal particles adhered to the fabric surface to substantially eliminate removal of such metal particles from the fabric substrate due to abrasion encountered during fabric use, atmospheric conditions and/or harsh laundering conditions.
[0018] Any fabric can be utilized in this invention provided that the polyurethane latex thoroughly coats the metal particulate coating of the fabric so as to substantially prevent contact between the metal and atmospheric oxygen or harsh oxidizing (and thus corrosive) chemicals present within laundry applications. Fabric comprising polyamide yarn, e.g., nylon, is most preferred. However, any natural fabrics such as cotton and ramie, or any synthetic fiber material such as, polyester, other polyamide, polypropylene, polyester-polyurethanes such as Lycra (Tradename), available from E. I. duPont deNemours and Company, Wilmington, Del., and the like; or any blends of synthetic fibers may be utilized within the inventive fabric. While plain weave construction is preferred, fabrics may be woven in plain, rip-stop, twill, satin or crepe constructions. The fabric yarns may range from single to double ply, 30 to 300 denier and 34 to 150 filaments. The preferred yarn in both the warp and filling direction is single ply, 40 denier with 34 filaments. It is preferred to use a flat warp yarn and textured filling yarn, but either type may be used in either the warp or filling. The preferred finished fabric yarn count when using 40 denier yarn is 170 warp yarns per inch and 140 filling yarns per inch. However, the warp yarn count when using 40 denier may vary from 80 to 200 and the filling from 80 to 200. Additionally, the yarn count can vary considerably depending on the yarn denier.
[0019] Prior to metallizing, the fabric can be scoured clean and dried. At this point, the fabric can be metallized, preferably with aluminum. This process includes applying a very thin layer of aluminum to a surface of the nylon fabric with a technique known to those of ordinary skill in the art of metallizing fabrics and film.
[0020] The preferred method of metallizing the fabric is by vacuum metal vapor deposition. However, metallizing of the fabric may be accomplished by any process which can be used to deposit metal onto a fabric and which bonds the metal to the fabric. The metallizing step may be carried out by other techniques such as metal sputtering, plasma treatments, electron beam treatments, chemical oxidation or reduction reactions, as well as currentless wet-chemical deposition.
[0021] The surface of the fabric may be modified by flame treatment, plasma discharge or corona discharge treatments to enhance adhesion of the metallic coating to the fabric before the metallizing step and/or before the encapsulation process to enhance adhesion of the polyurethane to the fabric.
[0022] Any metal generally utilized within a coating for fabrics may be utilized within this invention. The most common metal for this purpose, aluminum, is preferred because of its low cost and superior performance characteristics including radiant heat reflection in cold weather fabrics. Other metals which may be utilized include copper, gold, silver, nickel, zinc, titanium, chromium, vanadium and the like.
[0023] The metal layer on the fabric substrate in this invention preferably comprises aluminum, deposited by a vacuum deposition technique on the fabric substrate, with a thickness lying in the range of from 200 to 300 angstroms, i.e. 20 to 30 nm. This metallizing process is available from various vendors, including Diversified Fabrics of Kings Mountain, N.C. and National Metalizing of Cranberry, N.J.
[0024] The present invention utilizes a polyurethane latex over the metal coating of the target fabric to provide a barrier to corrosive elements resulting in a long-lasting radiant heat reflecting fabric.
[0025] The polyurethane component can be a waterborne aliphatic or aromatic polymer which provides a soft hand to the fabric substrate. As such, the preferred polyurethane is a dispersion comprising a polyurethane having an elongation of at least 150% and, conversely, a tensile strength up to 7000 psi. Particular examples of such dispersions include those within the Witcobond (Tradename) polyurethane series, from Witco Corporation, New York, N.Y., such as W-232, W-234, W-160, W-213, W-236, W-252, W-290H, W-293, W-320, and W-506, with W-293 being especially preferred. Acrylic polyurethane dispersions may also be utilized provided they exhibit the same required degree of elongation and tensile strength as for the purely polyurethane dispersions.
[0026] Any cross-linking agent compatible with polyurethanes may be utilized within this invention, particularly those which have low amounts of free formaldehyde. Preferred as cross-linking agents are Cytec (Tradename) M3 and Aerotex (Tradename) PFK, both available from BFGoodrich Co., Akron, Ohio. Any catalyst, which is generally necessary to initiate and effectuate cross-linking of a polyurethane dispersion, which is compatible with both a polyurethane and a polyurethane cross-linking agent may be utilized within this invention, e.g., Cytec (Tradename) MX, available from BFGoodrich Co.
[0027] Adhesion promoters which serve to promote adhesion between the aluminum and the polyurethane can also be present in the cross-linked polyurethane latex. Such adhesion promoters include polymers selected from the group consisting of silanes and phosphates. An adhesion promoter phosphate polymer can be applied in 0.1-1.0% percent add-on on the weight of the fabric (owf). Amino-silane compounds available from Gelest in Tullyton, Pa. can be used in the 0.1-2.0% add-on owf.
[0028] The cross-linked polyurethane latex of the invention may be present in any amount and concentration within an aqueous solution for use on and within the target fabric. Table 1 below indicates the difference in performance of the cross-linked polyurethane latex in reference to its concentration and dry solids addition rate on the fabric surface. Preferably, the concentration of the polyurethane is from 5 to 100% by weight of the utilized aqueous solution; more preferably from 10 to about 75% by weight; and most preferably from 25 to about 50% by weight. The coating addition rate measured as the percent of dry solids addition owf of the cross-linked polyurethane dispersion is preferably from 3 to 50% owf; more preferably from about 6 to about 40% owf; and most preferably from about 15 to about 30% owf, say about 10%.
[0029] As noted below, the basic procedure followed in applying this cross-linked polyurethane dispersion entails first providing a metal-coated fabric. Next, the latex is formed by combining the polyurethane with the cross-linking agent and, optionally, a catalyst to effectuate such cross-linking of the polyurethane. The resultant latex is then diluted with water to the desired concentration which will provide the most beneficial washfastness of the metal coating after treatment. The metal-coated fabric is then saturated with the resultant aqueous solution of the polyurethane latex with the excess being removed. Such saturation and removal of the latex may be performed in any standard manner, including dipping, padding, immersion, and the like for initial contacting of the dispersion; and wringing, drying, padding, and the like for the removal of the excess. The treated fabric is then dried and cured for a period of time, preferably at a temperature sufficient to effectuate a complete covering of the metal particles previously adhered to the target fabric surface. For example only, a temperature between about 300° and 450° F.; preferably between 310° and 400° F.; more preferably from 325° and 385° F.; and most preferably between 350° and 370° F. are workable. Times of from 2 to 30 minutes are preferred for this drying and curing step with a time between about 2 and 10 minutes most preferred.
[0030] Any other standard textile additives, such as dyes, sizing compounds, and softening agents may also be incorporated within or introduced onto the surface of the apparel fabric substrate. Particularly desired as optional finishes to the inventive fabrics are soil release agents which improve the wettability and washability of the fabric. Preferred soil release agents include those which provide hydrophilicity to the surface of polyester. With such a modified surface, again, the fabric imparts improved comfort to a wearer by wicking moisture.
[0031] The preferred soil release agents contemplated within this invention may be found in U.S. Pat. Nos. 3,377,249; 3,540,835; 3,563,795; 3,574,620; 3,598,641; 3,620,826; 3,632,420; 3,649,165; 3,650,801; 3,652,212; 3,660,010; 3,676,052; 3,690,942; 3,897,206; 3,981,807; 3,625,754; 4,014,857; 4,073,993; 4,090,844; 4,131,550; 4,164,392; 4,168,954; 4,207,071; 4,290,765; 4,068,035; 4,427,557; and 4,937,277. These patents are accordingly incorporated herein by reference.
[0032] Another significant characteristic of this fabric is its ability to prevent migration of insulating materials, feathers, down, and synthetic fibers, through the fabric's thickness. The ability of the fabric to prevent the migration of insulating materials is maximized when the voids at the interstices between overlapping yarns in the fabric are minimized and is achieved in this fabric through a combination of high yarn count construction, polyurethane coating, and calendering. Evaluating the ability of the fabric to prevent insulation migration was achieved using Federal Standard 191, Test Method 5450 (ASTM standard D737). A reduction in air permeability directly relates to a reduction in insulation migration through the fabric. To further reduce air permeability, a number of approaches have been taken. U.S. Pat. Nos. 5,073,418 to Thornton et al.; 5,011,183 to Thornton et al.; 4,977,016 to Thornton et al.; and U.S. Pat. No. 4,921,735 to Bloch, all of which are incorporated herein by reference, disclose providing low permeability characteristics through the use of mechanical deformation processes, e.g., calendering, to close the voids at the interstices between overlapping yarns in the fabric. Calendering of the present fabric may be carried out at any suitable point in its manufacture, e.g., prior to coating with metal particles, after metallizing but before treatment with polyurethane latex, or after such treatment.
[0033] Preferably, the metallized fabric of the present invention has an air permeability of not greater than 5 and not less than 1 cubic feet per minute (cfm) per square foot of fabric at a differential pressure of water at 125 Pascals of differential pressure, when measured in accordance with Federal Test Method 5450. Most preferably, the air permeability is equal to about 3 cfm, to allow some air flow through the fabric so that the insulating materials can dry after exposure to moisture, yet prohibit the migration of insulation, e.g., down, through the fabric.
[0034] The fabrics of the present invention are particularly well suited as inner-layer barrier fabrics such as liners for cold weather garments, pillows, sleeping bags, comforters and disposable industrial garments (e.g., protective and medical barrier apparel), due to their ability to 1) retain a substantial amount of metal particles within and on the target fabric after a long duration of wear and repeated standard launderings; 2) retain a substantial amount of heat due to the presence of a large amount of heat-reflecting metal particles within and on the target fabric; and 3) prohibit the migration of insulating materials, e.g., feathers, down and synthetic materials such as hollow fibers, through the fabric.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] The following examples are indicative of the preferred embodiment of this invention:
EXAMPLE 1
Shows Function of the Coating and Level
[0036] A 100% polyester, 4×1 sateen woven fabric (115/34 warp-drawn warp yarn and 150/50 textured fill yarn, having a fabric weight of 3.5 ounces per square yard) was evaporation-coated with 0.24 wt. % of aluminum produced by Diversified Fabrics, Inc. of Kings Mountain, N.C. A latex mixture of 100 grams of Witcobond® W-293, available from Witco of Chicago, Ill., 1 gram of Cytec M3 (crosslinking agent), available from of B F Goodrich of Charlotte, N.C., and 1 gram of Cytec MX (cross-linking catalyst), available from BFGoodrich of Charlotte, N.C., were then blended together in a beaker. This mixture was then diluted with water to varying concentrations as set forth in the Table below. Different swatches of the aluminum-coated fabric were then saturated with these various polyurethane latex mixtures and squeezed between two wringers in order to remove excess latex. Each fabric sample was then dried and cured at 360° F. for about 5 minutes. Each treated swatch was then washed according to AATCC Test Method 130-1995, “Soil Release: Oily Stain Release Method” and measured for aluminum retention after different numbers of washes. The washfastness of the latex encapsulated remaining aluminum was calculated through the utilization of a % ash test according to AATCC Test Method 78-1989, “Ash Content of Bleached Cellulosic Textiles.”
TABLE 1 Latex Coating Concentration Addition Rate Washfastness (wt. % of (% dry solids (% Al remaining after X washes) aqueous soln.) add'n owf) X = 3 X = 10 X = 20 0 0 2.3 4.5 4.5 2.5 1.7 22.7 11.4 6.8 5.0 3.3 31.8 27.3 27.3 10.0 6.0 65.9 43.2 40.9 15.0 8.3 68.2 59.1 45.5 25.0 15.0 88.6 75.0 75.0 50.0 26.7 90.9 86.4 86.4 75.0 36.0 86.4 77.3 72.7 100 49.0 86.4 84.1 84.1
[0037] As is clearly evident, the washfastness of the aluminum improved dramatically first upon utilization of the cross-linked polyurethane encapsulate, and second, upon utilization of greater concentrations of the latex up to a 50% by weight concentration of the cross-linked latex in aqueous solution.
EXAMPLE 2
Shows Function of the Adhesion Promoter
[0038] A 100% Nylon 66, plain weave, woven fabric (1/40/34 flat warp yarn and 1/40/34 textured fill yarn, having a fabric weight of 1.8 ounces per square yard) was vacuum metal vapor deposited on one side of the fabric with 0.32 wt. % of aluminum produced by Diversified Fabrics, Inc. of Kings Mountain, N.C. A latex mixture of 42% Witcobond® W-293, available from Witco of Chicago, Ill., 1.3% Freerez PFK, available from of Freedom Textile Company of Charlotte, N.C., 0.3% Cytec MX cross-linking catalyst, available from BFGoodrich of Charlotte, N.C., 0.2% SynFac™ TDA-92, available from Milliken Chemical of Spartanburg, S.C., and 0.4% ammonia was blended in a beaker. Another identical latex mixture was made to which 0.3% phosphate containing adhesion promoter was added. The promoter is a copolymer which is comprised of at least two different monomers: (i) a phosphate-containing vinyl monomer, i.e., ethylene methacrylate phosphate (available from Albright & Wilson, Birmingham, UK, under the tradename Epicryl™ 6835) and (ii) a second, separate vinylic monomer containing at least one reactive group capable of covalently reacting with the cross-linking agent present within the polyurethane latex coating, i.e., N-methylolacrylamide (available from Cytec Industries, West Paterson, N.J., under the tradename Cylink® NMA. The first and second monomers are added in a ratio of 0.8:1 to about 1:0.8.
[0039] Fabric samples were then dipped into each solution and pressed between two pad rollers to achieve a 30% addition of coating. The polyurethane latex was observed to actually encapsulate the entire bundle, including metal particles. The fabrics were then dried and cured at 360° F. for 3 minutes. A sample of fabric that was only metallized and a sample of metallized fabric that was dipped into each of the two latex coating systems were washed according to AATCC Test Method 130-1995, “Soil Release: Oily Stain Release Method” and measured for aluminum retention through 5 wash cycles. The washfastness of the remaining aluminum on each of the samples was calculated through the utilization of a % ash test according to AATCC Test Method 78-1989, “Ash Content of Bleached Cellulosic Textiles.” The results were tabulated as follows in Table 2 below.
TABLE 2 Washfastness (% Al remaining after X washes) X = Number Metallized Latex Latex w/Adhesion of Washes Only Coated Promoter X = 0 100 100 100 X = 1 0 69 78 X = 2 0 50 63 X = 3 0 44 63 X = 4 0 31 60 X = 5 0 25 60
[0040] As is clearly evident, the washfastness of the aluminum improved dramatically first upon utilization of the cross-linked polyurethane encapsulate, and second, upon the addition of an adhesion promoter.
EXAMPLE 3
Shows Function of Calendering
[0041] The fabric of Example 2 with the cross-linked polyurethane encapsulate and the adhesion promoter is used as the inner layer (lining) of an insulated cold weather jacket containing a thermal insulation core of down insulation or hollow synthetic fibers of synthetic plastic material such as Thinsulate (Tradename) or Hollofil (Tradename) which act to trap air and minimize convective heat. The metallic layer is positioned in the garment to face the exterior body surface of the wearer. The use of this fabric as a lining fabric requires it to prohibit the migration of insulating materials through the fabric.
[0042] The outer layer may be a porous, non-woven fabric formed of polyester or other synthetic fibers that may or may not be laminated to a film to improve water proofness and breathability, such as Goretex (Tradename) fabric available from W. L. Gore and Associates, Elkton, Md.
[0043] The ability to resist the migration of insulating materials through the lining fabric is achieved through construction, the polyurethane latex and calendering. The fabric of Example 2 with the cross-linked polyurethane encapsulate and the adhesion promoter was calendered during the final processing step at various temperatures and pressures. The results of said testing are provided in Table 3 below.
TABLE 3 Air Permeability As measured by Federal Method 191-5450 Calender Calender Pressure Temperature 800 psi 1000 psi 1200 psi 200° F. 12.4 9.8 8.1 250° F. 10.2 8.1 7.6 300° F. 7.6 6.8 5.1 350° F. 5.6 4.1 3.1 400° F. 2.1 1.9 1.4
[0044] As is clearly evident, the ideal air permeability (3 cfm at 125 pascals of differential pressure) was achieved at 350° F. and 1200 psi.
[0045] There are, of course, many alternative embodiments and modifications of the present invention, which are intended to be included within the spirit and scope of the following claims.
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A washfast and down-proof metallized fabric which comprises a metallic side, a non-metallic side and a cross-linked polyurethane latex coating over both sides which encapsulates said metal particles, its method of preparation and articles of clothing comprising such fabric are described.
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BACKGROUND OF THE INVENTION
The present invention relates to a compact cross-channel mixer having several stacked foils whereby flow channels are formed due to a special design of the foils, e.g., a sine wave design, and whereby the flow channels of foils that are positioned on top of each other cross each other.
A cross-channel mixer is known from WO 91/16 970, in which each mixing element is composed of a foil package. The foils are provided with a corrugated shape so that flow channels are formed when the foils are stacked onto each other. These flow channels are positioned cross-wise when the foils are stacked. When mixtures of fluids and suspended solids flow through, homogenizing occurs in the stacking plane. In order to achieve a thorough mixing in the radial and circumferential direction, several, however at least two, of these equally designed mixing elements are tacked on top of each other such that their stacking planes are rotated, e.g. by 90°. Because of two or more mixing elements arranged in series, such a mixer is not only expensive but also requires a large mounting space, which causes problems with respect to the available mounting space, e.g., when they are mounted into exhaust gas systems of motor vehicles.
In contrast thereto, it is an object of the present invention to develop a cross-channel mixer which consists of a single mixing element only, however still achieves good homogenizing across the entire cross section.
SUMMARY OF THE INVENTION
This object is solved by the inventive cross-channel mixer in that the foils, which are stacked to form a mixing element, are rotated about the main flow direction.
By rotating the stacked foils about the main flow direction, a good mixing in the radial direction and in the circumferential direction is achieved without the necessity of stacking two or more mixing elements on top of one another.
It is advantageous to vary the gradient of the flow channels in order to facilitate machining of the foils because they have a tendency to shift off laterally when they are rolled at a steeper gradient.
An advantageous rotation is achieved when the foils are rotated about the main flow direction in an S-shape. Inhomogeneous fluid/suspended solids-mixtures applied in the vicinity of the axis of the mixing elements are distributed about the entire cross-sectional surface and are homogenized. Furthermore, the mixing path is expanded by the rotation.
A further advantageous embodiment is achieved when the wave crests of the stacked foils forming the flow channels are provided with slots at an angle relative to their main extension direction. An improvement in the radial mixing action is achieved by the slots.
The chemical reactions can be activated by coating the foils with a catalyst.
BRIEF DESCRIPTION OF THE DRAWINGS
The object and advantages of the present invention will appear more clearly from the following specification in conjunction with the accompanying schematic drawings, in which:
FIG. 1 shows a plan view of a cylindrical cross-channel mixer;
FIG. 2 shows a cross sectional view along line II—II showing the flow channels arranged cross-wise;
FIG. 3 shows an inventive cross-channel mixer with a foil rotated in an S-shape;
FIG. 4 shows a plan view of a foil having a variable gradient of the flow channels;
FIG. 5 shows a foil according to FIG. 4 in which the wave crests of the flow channels are provided with slots.
FIG. 6 shows how the gradient in the flow channels is varied during production of the foils.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described in detail with the aid of several specific embodiments utilizing FIGS. 1 through 5.
FIG. 1 illustrates, viewed in the main flow direction, a cylindrically designed mixing element 1 which is designed according to the prior art as a cross-channel mixer having foils 2 stacked on top of one another. The foils are, for example, shaped as a sine wave so that flow channels are formed when the foils 2 are stacked on top of one another to form a package. The wave-shaped design is indicated by a foil 2 a . In order to achieve a mixing in the direction of the planes of the foils 2 the flow channels of two foils stacked on top of each other cross each other, as can be seen from FIG. 2 . The mixing element 1 shown in FIG. 1 can, therefore, only carry out a mixing action in the direction of the foils 2 as it is indicated by an arrow. However, if a mixing action is also desired in other directions so that a thorough mixing is carried out about the entire cross-sectional surface, at least two of such mixing elements 1 have to be connected in series, rotated toward each other by 90°, which, of course, results in high costs and a large mounting space.
FIG. 2 shows a cross sectional view along line II—II of a foil 2 having flow channels 3 a and a foil with flow channels 3 b , whereby this foil is positioned underneath foils 2 and is indicated by dashed lines. The flow channels are arranged cross-wise in a known manner so that a mixing occurs in the plane of the foils.
The general concept of the invention is illustrated in FIG. 3 . The mixing element 1 is again composed of foils 2 which may have a wave-shaped design as they are shown in FIGS. 1 and 2. The space between foils stacked on top of one another forms flow channels 3 a , 3 b which are positioned cross-wise on top of one another as this can be clearly seen in FIG. 2 . According to the invention, the foils forming these flow channels 3 a , 3 b are rotated about the main flow direction (in an S-shape in the shown embodiment). By this rotation, the planar mixing plane, as it is indicated by the arrows at reference numeral 4 , is bent so that a thorough mixing can now also be carried out radially without the necessity to connect in series a second mixing element as this is required according to the prior art. The inventive mixing element, therefore, saves significant mounting space and costs.
An improvement of the radial thorough mixing can be achieved by providing slots in the flow channels 3 a , 3 b as is described with the help of FIGS. 4 and 5.
FIG. 4 shows a view of a foil 2 in which flow approaches in the main flow direction indicated by the arrow. The flow is diverted in the direction of the flow channels 3 a . In the foil arranged underneath, the diversion is designed in the direction of the flow channels 3 b which are indicated by dashed lines. The gradient of the channels 3 a , 3 b can be varied in order to facilitate the machining. When the gradient is large, the foils 2 attempt to shift during the rolling process, a fact that is difficult to control with the desired small thickness of the foils 2 . However, a thicker design of the foils 2 increases the costs and the mounting space.
When slots 6 are formed in the foils, 2 according to FIG. 5, the wave crests selected representatively and designated by the reference numerals 5 a , 5 b are cut and an exchange of material can occur, perpendicular relative to the plane of the drawing, with the flow channels of the plane positioned underneath so that the radial mixing action described in FIG. 3 is intensified even further.
A further improvement can be achieved by coating the foils 2 with a catalyst. Thereby, the function of a chemical transformation is integrated into the mixer.
The inventive compact cross-channels mixer, therefore, permits homogenizing of a mixture about the entire cross section, requiring a small mounting space and low structural requirements and financial expenditure resulting therefrom.
The specification incorporates by reference the disclosure of German priority document 198 44 075.8 of Sep. 25, 1998.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.
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A compact cross-channel mixer having several stacked foils is provided whereby flow channels are formed due to a special profiling of the foils, e.g., a sine wave design. The flow channels of foils that are positioned on top of each other. The stacked foils that form a mixing element are rotated about the main flow direction.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-in-Part of co-pending U.S. patent application Ser. No. 13/855,038, filed on Apr. 2, 2013, which claims the benefit of Provisional Patent Application Ser. No. 61/686,226 filed on Apr. 2, 2012, now expired. The entirety of both the co-pending non-provisional and expired provisional applications are herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This application relates generally to an operational system improvement for reloading firearms, such as the M16 and others, to be operated by the use of Gas-Piston systems. The M16 rifle platforms are improved by the addition of a set of mechanisms integrating in one unit, an extra lateral, ambidextrous, frontal, non-reciprocating charging handle, or sliding hand guard, acting in conjunction with a regulated gas piston-cylinder couple direct drive system of easy installation, not requiring any machining or permanent modification of the standard M-16 receiver. This array of mechanism and operational system may be utilized as well in other types of auto loading firearms for use as an OEM design or by making the suitable parts dimensional modification to fit operationally.
BACKGROUND OF THE INVENTION
[0003] The use of the high pressure gasses inside the barrel of firearms to propel direct drive rods to force the unlocking of the bolt and allows its recoil is very old (present within firearms such as: AK 47, AK 74, AK (10)1, FAL, Galil, G3 H&K, FN 49, SKS, SVT (40), just to name a few). Recently, several manufacturers like Bushmaster, Remington, Smith & Wesson, Rugger, Annalite, and Heckler & Koch have incorporated the use of the direct drive gas systems to substitute the gas impingement system of the original M16 rifles and platforms alike, including the manufacture of retrofits. The automatic cycle of the ejection of used shells, and reload of new rounds into the barrel chamber is made possible by bringing into being an aged combination of pistons, cylinders, push rods, and springs utilizing the high pressure gasses to generate a strong rearwards displacement of the push rod, that in turn impacts a solid spot of the bolt carrier, inside the receiver, unlocking and displacing the bolt rearwards. There are numerous, nearly identical systems, now in fashion, that perform in a similar manner and are being supplied as standard from the factory or as retrofit kits (such as noted as noted above as it concerns such other firearm manufacturers in relation to improved versions of M16 and even AR 15 platform rifles).
[0004] However, none of these direct drive gas piston systems take advantage of mechanical elements already in place to go one significant step forward in solving the notorious disadvantage of the M16 and platforms alike in terms of uncomfortable rear charging action involved. Such action must be performed by pulling, straight back, a T Charging Handle located at the rear of the receiver. This is a very uncomfortable maneuver, against all ergonomic principles, forcing the firer to decompose his firing posture to the extent that it may reveal his location to the enemy.
[0005] Several attempts have been undertaken to replace the OEM gas impingement system of the M-16 or AR-15 rifles platform by a direct drive gas piston system. The M-16 is notorious for fouling and jamming due to the original design requiring the discharge gas be directed through a gas impingement tube into the bolt carrier to urge the bolt displacement to the rear in response to the firing of a cartridge and produce the expel of the spent shell and the reloading of a new round into the barrel rear end, for instance.
[0006] Most of the guns utilizing gases to assist in the opening of the bolt avoid the gas impingement system, including the AK 47, AK 74, AK (10)1, FAL, Galil, G3 H&K, FN 49, M1, M2 Carbine, M (14), SKS, BAR, FN SCAR, and Remington ACR, just to name a few. These types basically utilize a combination of rods and pistons, either being of Short stroke or Long stroke action. In a short stroke actuator system, the moving part energetically impacts a push rod, temporary contacting the bolt for a short distance of about half an inch, sufficient to move and unlock the bolt and allow the still pressurized chamber and barrel to exert its high pressure against the bolt urging its motion backwards to cause an automatic reloading operation. In Short Stroke gas Piston-Cylinder systems, the two latter named components remain uncoupled, moving linearly one inside the other, for a short distance, within the gas block body.
[0007] In a Long Stroke actuator system, the push rod is permanently connected to the bolt and moves with it as a single Part, displacing for a long distance, operating inside a long tube cylinder which originally transmits energy and motion to the part promoting the opening of the unlocking of the bolt and the complete rearwards motion the cause the reloading. This latter system is typically represented in the AK 47 rifle.
[0008] The majority of the above mentioned rifles have an external, reciprocating charging handle connected to the bolt that can potentially harm the firer in its rearwards strong displacement when firing. Others have developed systems to repine the OEM gas impingement system. Some require that significant portions of the rifle be modified or replaced, such as the barrel and parts within the receiver. These systems have obvious drawbacks. The cost of replacing the barrel and other parts is substantial and unnecessary. If machining is required to install the system, the user must send the rifle to a machinist or gunsmith to be modified, added time and expense to the process, and potentially, introducing error with each independent machining process.
[0009] Some manufacturers have designed systems that do not require the replacement of the barrel and are an improvement over the OEM and previous systems, such as those manufactured by Land Warfare Resources Corporation (LWRC), Bushmaster, Adams, Smith & Wesson, Rugger, Remington Heckler & Koch H&K 416, DPM, and Armalite. Moreover, Rock River also recently introduced a rifle having the Frontal Charging System and Direct Drive combination that works only with its proprietary design of an extended Upper receiver and cannot be incorporated to any existing M16 or AR 15 rifle platform. Adcor recently manufactured a rifle providing a combination of frontal charging handle and Direct Drive system, while maintaining the traditional rear charging handle. However, this improvement demands a profound change in the rifle design, and requires for its operation to work in cooperation with the main spring and a frontal extension of the upper receiver. It is not a simple addition to an existing M 16, AR 15 rifle platform that can be added as a retrofit kit, or a simple addition to the production of conventional rifles of that category.
[0010] Other important patents to mention are; U.S. Pat. No. 3,246,567, Miller; U.S. Pat. No. 4,244,273, Langerdorfet; U.S. Pat. No. 4,765,224, Morris; U.S. Pat. No. 5,351,598, Schutz, which have in common the utilization of a gas-piston direct drive, and one of them U.S. Pat. No. 6,634,274, Herring; even a structural protecting tube through which the actuating bar moves, and all of them keep the OEM T charging handle of the system, reason for which the problems associated with the rear charging operation by the OEM T handle subsist.
[0011] Generically all gas-piston direct drive systems utilize an actuator pneumatic combination of a cylinder, either static or mobile, receiving high pressure combustion gases from a piston, either static or mobile, and wherein the moving part displaces to impact a push bar to move a part of the bolt with sufficient energy to unlock the bolt and allow its opening. Interesting is to notice the very small differences in recently awarded patents with respect to gas-piston mechanisms utilized successfully since the 1940 s like the FN 49 rifle and then by the FAL rifle.
[0012] Almost identical is the Adams gas piston system in which the major improvement comes from the ability to extract, for cleaning, in a single piece, the rod and the cylinder, which are a single integral part in their design.
[0013] None of these existing systems provide any means to enable, as well, the manual charging action from the front of the rifle. Further more, none of these systems operate inside an easily attached structural tube to contain, guide, and protect the components of the system. None of the above mentioned combinations can be installed in existing M16 or AR15 rifle platforms as a retrofit kit of quick installation or removal without extensive irreversible modification to the receiver.
Prior Art Disadvantages
[0014] In general, in all previous solutions attempted up to now to replace the gas impingement system, the direct drive gas piston systems use actuator rods, which, at a certain instance of the action, where the cylinder uncouples the gas piston portion it operates in cantilever of tong length, being supported weakly only at the rear extreme by a portion penetrating inside the receiver without any other support, situation which generates disturbing harmonic vibrations affecting the performance of the system, overstressing the rod bar, and demanding thicker sections of the part.
[0015] The M16-M4 family of rifles is excellent in many respects, and both have undergone upgrades, however, there are still several detrimental flaws inherent to its original design. The most significant flaws are listed below.
Flaws Related to the OEM Gas Impingement System:
[0016] The gas impingement system is a source of gas residues and dirt accumulation causing malfunctioning. The disadvantages of the OEM gas impingement system are well known, primarily due to the hot, dirty gases being directed into the bolt carrier and receiver. The heat alone tends to wear parts down, exposing this area to thermal cycling. With the addition of soot or carbon from the expelled gasses, the moving parts within the bolt carrier and receiver are exposed to a hostile environment. This is exacerbated by the constant need to lubricate this entire area; the oil serving to trap particles and carbon. This combination of factors cause the parts to break, wear, or operate improperly. The areas of failure can include the fouling and wear of the gas rings, loosening of the ejector and extractor springs causing the spent shell to not be ejected properly, the bolt carrier is prevented form traveling properly within the receiver, as the chamber becomes fouled and increases in temperature causing the entrapment of the spent shell, the melting of the gas tube causing a restriction of flow to the bolt carrier and subsequent failure. Basically, to ensure the proper operation of the rifle, it must be cleaned and continually lubricated, With many parts to keep track of, consistent cleaning is more difficult in the field.
Flaws Related to the Position of the T Charging Handle in M 16 Rifles:
[0017] Conflicting with ergonomy and shooter's comfort, and the restriction to use large scopes; the M-16 or AR-15 has a charging T handle located at the rear of the receiver that is notorious for the difficulty to the firer to perform the charging action in a comfortable manner, conflicting with human ergonomy, and keeping the required body movements within few number of operations in short displacements. The charging maneuver is required when there is a malfunction in the fire cycling: a misfiring; a bad cartridge ejection; a jamming, and a new magazine to load; a bad cartridge, situations which are common when shooting.
[0018] When firing from the standing position, the Charging action of a M16 demands the following body maneuvers: the supporting hand stops holding the gun from the front and leaves the front of the rifle in cantilever, leaving the controlling hand responsible of keeping the gun horizontal and creating a large moment about the wrist of the controlling hand; then the supporting hand approaches and grabs an original T charging handle placed about 3 inches above relative to the of the wrist of the controlling hand, in a movement that involves the full lateral articulation of the wrist to the side; then pulls linearly horizontally for about 5 inches with rearwards with a force of about 15 pounds in a region where the arm has nearly completed its articulation about the elbow, and has to be further assisted by a rotation of the torso; then release the T handle; and return to the front to assist in supporting the rifle at the front.
[0019] In the kneeling position the same body posture decomposition is required, however, due to body balancing reasons it often requires to abandon the position causing more discomfort, and possibly compromising the concealed firer position.
[0020] In the prone position it is very difficult to charge fast because the elbow of the supporting hand has to leave the ground to bring the supporting hand back to be close to the top of the wrist of the controlling hand to pull back the T handle, resulting in a very uncomfortable posture. Some shooters totally decompose the posture by projecting the controlling hand holding the rifle muzzlewards to approach the supporting hand to combinedly perform the charging maneuver.
[0021] These ergonomic inconveniences have very negative tactical repercussions directly reflecting in much longer time required to have a good sight picture to be back on target, and which is worse compromising the position of the firer
[0022] As a consequence of the above there are flaws related to the restriction to use of certain optical devices:
[0023] The original position of the T charging handle in the M 16 at the rear of the receiver conflicts in Vertical space with the use of powerful telescopic sights, which are normally large in diameter at the ocular lens at the rear. That conflict of interfering space has required developing a special type of short telescopic sights for M16, suitable to partially resolve the space conflict, but depriving the shooter of the benefits of a large scope reflecting in low optical power, and narrow angle of vision.
[0024] Costly Tactical and combat performance difficulties derived from the above mentioned limitations are reflected in:
[0025] the loss of valuable time to get back on target, due optically to eye readjusting and target acquiring; the deprivation of the use of large powerful scopes; the visual loss of the target, loosing track of target happenings and scenario; the loss of time due to body position readjusting; jeopardizing the concealment of the shooter's position; the loss of accuracy due to recent strong fine muscular activity; the loss of time due to body repositioning; the buildup of emotional stress; the frustration buildup due to loss of potential firing opportunities; the dangerous potential of compromising the shooter location; the potential of scope misadjusting due to conflicting area with T handle; the jamming due to known OEM gas impingement system; the need of frequent cleaning to remove dirt related to the use of OEM gas impingement system; and, most aggravating of all, perhaps, is the unquestionable fact that the T handle charging maneuver requires significantly more time to get effectively back on target after reloading, particularly when compared to any other military rifles. Other noticeable problems include: the time required to be effectively back on target exceeds in average 8 seconds more than comparative rifles; the excess of time is due to the need of moving the eyes away from the target, the body maneuver of positioning the rifle relative to the body in a proper position to pull the T Handle, the repositioning of the body to a proper firing position, relocating the target in the seen, aligning of sights, and the adjustment of one's mind and body to shoot; not to mention the time extension excess to get effectively back on target is critical life-threatening in military and law enforcement use.
[0026] What is needed then, and not heretofore provided by the existing art, is a combined solution to both of the mentioned flaws organized, integrated in one single array of mechanisms: Which is a combination of frontal charging handle, being ambidextrous and not reciprocating, working in association with a system to replace the OEM gas impingement system of the rifle. What is further needed is a system that can be easily installed in any existing M 16, AR 15 rifle platform, not requiring any machined modifications to the receiver, or replacement of the barrel and other primary parts of the rifle. What is further needed is a system that is easily assembled and disassembled in the field, by minimizing complexity and the overall number of parts. What is again needed is a retrofit system that can be removed for inspection and cleaning without substantial disassembly of neighboring parts, such as the gas block or hand guard. Even more, what is needed is a charging handle to pull back located in the frontal area being ambidextrous, non-reciprocating. What is needed is an array that enables the charging operation to take place alternatively with the supporting hand normally positioned at the front to reduce the time consuming and very uncomfortable charging operation of the M 16 family of rifles by pulling the T handle at the rear.
[0027] What is needed is a frontal lateral charging handle or a horizontally sliding Hand Guard or handle connected to a floating charging handle enabling the charge operation to be performed by the so called “pump action”, reloading operation without leaving the supporting hand of the firer away from the front of the rifle without suspending its supporting function. Moreover, what is needed is a charging mechanism capable of operating in tandem with the original T charging handle. Furthermore, what is needed is system complying with all of the above mentioned solutions, and still be capable of operating in tandem with the original rear charging handle without requiring its removal or interfering with its independent action. The use of a structuring tube to provide internal ground contact to moving parts to provide alignment, support and avoid vibration is needed. The tube serving as mobile ground to the linkage elements converts the array in a mechanism.
Advantages of the Invention
[0028] This invention is different and advantageous in comparison with prior firearm operating systems better for the following reasons:
[0029] It incorporates the use of frontal charging handle operating inside a structural solidly supported guide tube that eliminates the cantilever operation condition of most of the push bars and the associated damaging harmonic vibrations. In the known art, the gas piston cylinder actuator action takes place within the gas block, which has a short stroke displacement where the moving couple never separates one from the other to go and travel enough. This application combines in one device the solution to two flaws of the M16 rifle platforms: problems associated with the gas impingement system, and problems associated with the uncomfortable charging pulling action of the T handle at the rear. It improves the functioning reliability of the rifle, as well as the tactical performance by significantly reducing the recharging time; preventing the unnecessary potentially compromising body movements; and allowing the use of more powerful scopes. It is installable without requiring any machining or permanent modification on M16 and AR15 existing rifles widely used over the world without the significant addition of weight and preserving the original characteristic outlook. It can be uninstalled returning the rifle to the original condition. Due to the notorious advantages, it may o be adopted by an OEM for new production rifles. The OEM rear T handle remains completely independently operative with the frontal charging device of the inventive system, working in tandem. A selective rotary regulator knob located at the front of the gas block provides a range of gas selection. The system does not interfere with the semi automatic or full automatic modes. The world wide used M 16 rifles and platforms alike, are easily retrofitted with a single-piece solution. The system eliminates problems associated with the OEM gas impingement, which keeps the bolt and receiver cleaner and colder, the chamber and the breech, demanding less cleaning and providing a more reliable operation. A “Pump Action” charging action can be achieved by using a frontal horizontally sliding Hand Guard in combination with the ambidextrous, non reciprocating lateral charging handle. This invention drastically reduces time to reload and charge and drastically reduces the body movements required by the presently used to charge using the rear T handle. The new system has important tactical advantages derived from its use, such as favoring the installation of more powerful scopes. This compact system is better than all previously used direct drive gas systems because it uses supporting tube to reduce damaging harmonic vibrations of the push rod. The system provides an alternative embodiment having a gas block composed of two sliding disassemble bodies to facilitate the quick complete field disassembly for maintenance. Additionally, an adapter part or a plurality of them provide solid constrained rear support to a structural guide tube needed for the installation of this array of mechanisms without requiring any permanent modification or machining of the original receiver.
[0030] This invention provides a solution to two flaws by integrating an ambidextrous, non-reciprocating frontal charging system, combined with a direct drive gas piston to substitute the original gas impingement system. No permanent modification of the M-16 rifle or AR 15 platform rifles is needed to install this kit. No holes are drilled. No bushings need to be inserted. The original Cocking handle remains operative, or may be removed if wanted. The installation of the kit is reversible and can be executed within minutes.
[0031] This invention integrates in one unit the following features: an ambidextrous, non-reciprocating frontal manual side charging system solution, combined with a direct drive gas piston to urge the motion to the bolt carrier rearwards for a distance enough to be operative to eject a used cartridge and reload a live round into a barrel chamber. This invention can be factory installed in new rifles, or very simply mounted in existing rifles, as a retrofit kit, to operate in conjunction with the original rear charging handle, if desired, or completely eliminate the rear pulling charging device. It does not interfere with any other operation of that remarkable family of guns.
[0032] Its installation does not require hole drilling or permanent modifications to the rifle, and if desired, it can be uninstalled, and the rifle can be brought back to the original Gas Impingement system.
[0033] Additionally, the placement of the Charging Handle ( 30 ) at the front is very advantageous ergonomically and tactically because it lends to be pulled back with the supporting hand and arm extended in a region where the action of pulling is more comfortable end effortless under an ergonomic perspective, than pulling at the rear of the rifle in a region where the arm has nearly completed its articulation and has to be assisted by a rotation of the torso.
[0034] Since no gases go inside the receiver, or into the Bolt Carrier, both remain cleaner, and colder than the original M16 rifle platforms utilizing OEM gas impingement.
[0035] In addition, a gas Regulator can be incorporated to the system by the use of a Gas Plug Piston Regulator ( 40 ), a cylindrical gas conductor having a radial array with a plurality of holes of diverse diameter ( 40 D) to variably restrict at will the gas flow when aligning with the high pressure gas aperture ( 65 B).
[0036] It is easy to strip in the field. Gas Plug Piston Regulator ( 40 ) can be easily pulled out for cleaning, and the Floating Gas Cylinder ( 20 ) can be cleaned from the front without any further disassembly. If complete stripping is required it is possible to perform very easily when utilizing the two piece gas block consisting in the Lower Gas Block ( 60 ), coupled by sliding with the Upper Gas Block ( 50 ) towards the muzzle which allows the complete stripping of all of the parts except the Lower Gas Block ( 60 ).
[0037] Alternatively, a two piece tube, longitudinally cut, can be integrated to the interior of the hand guards in a manner that, when removed, exposes all the elements contained inside the tube for a thorough cleaning. In particular it is important to mention the differences and advantages with respect to Adams U.S. Pat. No. 7,469,624. This invention is better because it incorporates a Frontal, Lateral, Ambidextrous Non Reciprocating Charging Handle array that operates in conjunction, but independently from the gas direct drive system.
[0038] In order to accomplish the non reciprocating feature of the Charging Handle, the Push Rod ( 80 ), the Floating Gas Cylinder ( 20 ), and the Floating Charging Handle Cylinder ( 30 ) must be separated independent parts of a set. In order to provide alignment, support, rigidity, and positioning to the system the elements operate inside a Guide Tube ( 70 ) that is positioned and affixed to the rifle by means of a, Tube Support Adapting Plate ( 10 ), at the rear, and affixed to the undercut for Tube Support ( 50 )B at the front. This invention well surpasses and improves on Adams U.S. Pat. No. 7,469,624.
[0039] A major advantage and innovation of this invention is the fact that the conception of the Gas Block element offers in one embodiment either the One Piece Gas Block ( 65 ), or alternatively, in a different embodiment formed by two parts, being, The Lower Gas Block ( 60 ), and the Upper Gas Block ( 50 ). The latter offering the possibility of assembling or disassembling the unit by sliding the Upper Gas Block ( 50 ) from the front, without removing the Lower gas Block ( 60 ) from the Barrel ( 14 ) and thus assuring the proper alignment of the parts when it is put back together. This is a completely novel approach in the design and conception of Gas Blocks that facilitate the total disassembly of the unit from the front, for cleaning or installation purposes. The design of the above mentioned pieces is such that they press together one against each other due to a dual dove tail angular joint design when slid and pressed and locked frown the front.
[0040] When assembled, the final aspect of the Two Piece Gas Block ( 50 ) and, ( 60 ) is identical to the One Piece Gas Block ( 65 ) with respect to bores, cuts, dimensions, and functionality.
[0041] No permanent modification of the M-16 rifle o AR 15 platform rifles is needed to install this kit. The original M 16 Charging handle located at the rear of the upper receiver, may remain in place and active.
SUMMARY OF THE INVENTION
Terms and Definitions
[0042] The term “Charge” refers to the action required to load a new cartridge into the chamber of the firearm barrel and close the breech, leaving the weapon in a condition ready to fire.
[0043] The term “Supporting hand” refers to the hand supporting a rifle at the front.
[0044] The term “Controlling band” refers to the hand grabbing a rifle at the rear handle and pulling the trigger.
[0045] The term “Breechward” a direction towards the breech of the rifle.
[0046] The term “Muzzleward” a direction towards the muzzle of the rifle.
[0047] OEM means original equipment manufacturer.
[0048] The terms rod and push bar are used indistinctively.
[0049] Terms such as “under,” “over,” “in front of,” “the back of the gun,” or “behind,” “anterior,” “posterior,” “downward,” “upward,” or “transverse,” are used here as somebody firing a gun would understand them, which is by reference to the longitudinal or firing axis of the barrel when the gun is held in the usual horizontal attitude.
[0050] The term Floating Cylinder and Floating Cylinder Actuator are used indistinctively.
[0051] The term Floating refers to a part not secured in place, unattached, Inclined to move or be moved about.
[0052] The term “Pump Action” refers to reloading a repeating firearm in which a new round is brought from the magazine into the breech by a slide action in line with the barrel.
[0053] The operating system exposed in the present invention combines a gas piston-cylinder system, jointly working in cooperation with an external linkage mechanism manually actuated system functioning within a structural supporting tube frame. The operating system also finds application in other firearms seeking the benefits of a frontal, non-reciprocating, ambidextrous charging handle.
[0054] In one embodiment, this invention generally relates to solutions and improvement to the original design and operation of the M16 family of rifles which still has two detrimental flaws inherent to its original design.
[0055] The M-16 or AR-15 has a charging handle located at the rear of the receiver that is known for the difficulty to the firer to perform the charging action in a comfortable manner. The gas impingement system is a source of dirt buildup and malfunctioning. This application combines in one artifact the solution to the above mentioned flaws which in turn promotes other series of tactical benefits deriver from its use. It opens the potential to retrofit existing military rifles with a better charging mechanism that make unnecessary, for a time, the adoption of newer rifle design. A sliding “Pump Action” front Hand Guard operating in tandem with the existing rear T charging handle is a possible alternative solution. Moreover, the solution provided by the present invention is applicable to other firearms including rifles and shotguns which benefit from the advantages inherent to this operating system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] The drawings provided herein are intended to provide descriptions of the possible embodiments of the inventive firearm and accessories thereof. No scope limitations are intended nor should be construed in relation to such representations. Most of the drawings are self-explanatory; however for a better understanding of the advantages, capabilities and innovation of this invention, some of the drawings are explained in more detail. All drawings are shown in one of the preferred embodiments.
[0057] FIG. 1 is an illustration of a Plate Tube Support Adapting Plate ( 10 ) of the present invention in orthographic view and exploded perspective.
[0058] FIG. 2 is an illustration of a Floating Gas Cylinder ( 20 ) of the present invention in orthographic view and exploded perspective. The Floating Gas Cylinder Actuator is adapted to receive input energy from two sources: 1. Potential energy from high pressure gas and maximizing its force generation in an expansion chamber and; 2. Kinetic energy from an external source like the manual operation. In both cases, the Floating Gas Cylinder Actuator operationally transmits energy and motion to operationally actuate the Bolt Carrier to perform a complete reloading operation.
[0059] FIG. 3 is an illustration of a Floating Charging Handle Cylinder ( 30 ) of the present invention in orthographic view and exploded perspective.
[0060] FIG. 4 is an illustration of a Gas Plug Piston Regulator ( 40 ) of the present invention in orthographic view and exploded perspective.
[0061] FIG. 5 is an illustration of an Upper Gas Block ( 50 ) of the present invention in orthographic view and exploded perspective.
[0062] FIG. 6 is an illustration of a Lower Gas Block Lower Gas Block ( 60 ) of the present invention in orthographic view and exploded perspective.
[0063] FIG. 7 is an illustration of a One Piece Gas Block ( 65 ) of the present invention in orthographic view and exploded perspective.
[0064] FIG. 8 is an orthographic view of a bolt carrier key replacement ( 13 ).
[0065] FIG. 9 is an orthographic view of a Push Rod ( 80 ) and a Guide Tube ( 70 ).
[0066] FIG. 10 is an illustration of the complete direct drive retrofit system of the present invention in exploded perspective.
[0067] FIG. 11 is a schematic cut view of the complete system installed on an M 16 rifle utilizing the Plate Tube Support Adapting Plate ( 10 ), which couples sliding from the front with the OEM Barrel Nut, constraining the Plate Tube Support Adapting plate from rotation and lateral movement. The coupling with the structural support guide tube, which is locked at the front by the gas block, completes the total constringent of the Plate Tube Support Adapting plate.
[0068] FIG. 12 is a schematic isomeric view of a sliding front guard handle ( 95 ) coupled with the lateral external charging handle portion ( 30 A) to enable the “Pump Action” charging action.
[0069] FIG. 13 is an isometric schematic view of the installation of the Plate Tube Support Adapting Plate ( 10 ), which couples sliding from the front with the OEM Barrel Nut, part required for the installation of the system, object of this patent application in M16 rifles without requiring any permanent modification to the OEM receiver or other original parts. The Plate Tube Support Adapting Plate also provides alternatively support to a hand guard.
[0070] FIG. 14 is a schematic isomeric view of the Gas Piston System; jointly operating with a linkage mechanism manually actuated charging system as described in the operating system of this application.
[0071] FIG. 15 is a schematic isomeric view of the external linkage mechanism manually actuated charging system as described in this application in a certain embodiment.
[0072] FIG. 16 is a schematic isomeric view of the Gas Piston System as described in this application, in a certain embodiment.
[0073] FIG. 17 is a schematic isomeric view of a the slidably coupling of the floating gas cylinder actuator ( 20 ) with the Floating Charging Handle Cylinder ( 30 ) in a manner in which the interaction is limited to transfer of force and motion of from the Floating Charging Handle Cylinder ( 30 ) to the Floating Gas Cylinder Actuator ( 20 ) and not vice versa, due to the contactless nature of the linear relative motion. This condition grants the Non Reciprocating functioning of the Operating system described in this application.
[0074] FIG. 18 is a schematic isomeric view or an alternative array of the external linkage mechanism manually actuated charging system when used in combination of a conventional gas piston blocks. Notice the absence of the Floating Gas Cylinder Actuator. The motion promoted by a gas piston inside the Conventional gas block is exerted directly over the front face ( 80 A) of the push rod ( 80 ), operationally transmitting transmits energy and motion to operationally actuate the Bolt Carrier to perform a complete reloading operation.
[0075] FIG. 19 is a schematic isomeric view of the linkage array system itself, to operationally transmit motion to the bolt carrier by applying external rearwards force to the Floating Charger handle. Notice the presence in the array of the floating gas cylinder actuator ( 30 ), which is a part present in the mechanical linkage array, and in the gas-piston motion generating system.
[0076] FIG. 20 is a schematic isomeric view of an alternative array of the External Linkage Mechanism Manually Actuated Charging System when used in combination of conventional gas piston blocks. Notice the absence of the Floating Gas Cylinder Actuator. The motion promoted by a gas piston inside the Conventional gas block is exerted directly over the front face ( 80 A) of the push rod ( 80 ), operationally transmitting transmits energy and motion to operationally actuate the Bolt Carrier to perform a complete reloading operation. The array herein described, operating within a structural guide tube ( 80 ) may be utilized in existing designs of firearms using conventional gas piston systems to operate a push rod, given the proper adaptations for its use.
[0077] FIG. 21 is a schematic sectional view of the combined application of in a conventional gas block, showing several stages of the dual functioning of the linkage mechanism when energy derives from potential energy of the high pressure gas piston system, and when kinetic energy derives from external manual force.
[0078] FIG. 22 is a schematic sectional view of the operation of the linkage array when a conventional gas piston system is used. Notice that the Floating charging handle remains immobile as the push rod moves linearly through it in a contactless manner.
[0079] Name of the components and reference numerals.
Part Number Name
[0000]
10 TUBE SUPPORT ADAPTING PLATE
10 A REAR PINS
10 B BARREL HOLE
10 C ROD BORE
10 D HAND GUARD SUPPORT HOLE
11 TUBE SUPPORTING LUG
11 A ANULAR INSERTION CUT
11 B ROD BORE GUIDE
12 BARREL NUT
12 A SEMI CIRCULAR CUT
12 B HOLE FOR BARREL
13 BOLT CARRIER
13 A BOLT CARRIER GA KEY REPLACEMENT
14 BARREL
14 A BARREL GAS PORT
15 MAIN SPRING
20 FLOATING GAS CYLINDER ACTUATOR
20 A LATERAL ALIGNMENT GUIDE KEY/LATERAL STUD
20 B LATERAL EXHAUST PORT
20 C INTERNAL CYLINDRICAL CAVITY
20 D MAIN HIGH PRESSURE EXPANSION CHAMBER
20 E REAR CYLINDRICAL CAVITY
20 F SLIM PORTION
20 G FRONT ANNULAR FACE
20 H FRONT WALL
20 J LARGER DIAMETER
30 FLOATING CHARGING HANDLE CYLINDER
30 A LATERAL EXTERIOR CHARGING HANDLE
30 B CENTER BORE
30 C PIVOT HOLE
30 D ARTICULATED HANDLE EXTENSIONS
30 E PIVOTING PIN
30 F REAR FACE
30 G CYLINDER RING
40 GAS PLUG PISTON REGULATOR
40 A NARROW EXHAUST PORTION STUD/SECONDARY CYLINDER.
40 B LOCKING SEMICIRCULAR CUT
40 C EXTERNAL KNOB
40 D LATERAL REGULATING RADIAL APERTURES ARRAY
40 E GAS INJECTION PASSAGE
40 F ANULAR ROTATIONAL LOCK HOLES ARRAY
400 LOCKING DIMPLE
40 H GAS PLUG REAR FACE
40 I EXHAUST PORT
40 J PRIMARY CYLINDER
50 UPPER GAS BLOCK
50 A SECURING ROD BORE
50 B UNDER CUT FOR TUBE SUPPORT
50 C HIGH PRESSURE GAS APERTURE
50 D GAS PLUG PISTON REGULATOR BORE
50 E DOUBLE V DOVETAIL MALE
50 F RETENTION SPRING BORE
51 SECURING ROD
51 A RETAINING PIN
51 B RETAINING SLOTS
52 RETENTION PIN
60 LOWER GAS BLOCK
60 A BARREL BORE CLAMP
60 B HIGH PRESSURE GAS APERTURE
60 C DOUBLE V DOVETAIL FEMALE
60 D SCREW HOLES
60 E SCREW
65 ONE PIECE GAS BLOCK
65 A BARREL BORE CLAMP
65 B HIGH PRESSURE GAS APERTURE
65 CUNDERCUT FOR TUBE SUPPORT
65 D SCREW HOLES
65 E GAS PLUG PISTON REGULATOR BORE
65 F SECURING ROD BORE
65 G RETENTION SPRING BORE
65 H UPPER FACE
65 I SCREW
65 J RETENTION SPRING
65 K REAR FACE
66 CONVENTIONAL UNITARY GAS BLOCK WITH INTERNAL CONTAINED PISTON-CYLINDER ARRAY
66 A MOVABLE INTERNAL PISTON R CYLINDER TO CONTACT THE PUSH ROD
67 PROJECTILE
68 MAIN AXIS OF CO ALIGNMENT
69 HIGH PRESSURE COMBUSTION GAS
70 STRUCTURAL SUPPORTING GUIDE TUBE
70 A ENGAGING GROVES/SLOT CUT
70 B FORE END
70 C REAR RIND
70 D LOCKING PROTRUSIONS
70 E INTERNAL WALL OF TUBE
80 PUSH ROD
80 A FORE END
80 B REAR END
80 C CYLINDRICAL RING
80 D CYLINDRICAL RING FRONT FACE
90 COMPRESSION SPRING
91 SLIDING HAND GUARD
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0172] This invention focuses in providing solutions to at least two of the flaws, deficiencies and limitations of previous M16 platform designs. It is a careful trade of ergonomics, portability, fire power, fire comfort, ease of field service and manufacturing, preserving the compactness and conventional silhouette of the original design, and the ease of service and installation.
[0173] The embodiments provided herein provide, in a single mechanism array, a direct drive gas piston system, working simultaneously in cooperation with a frontal ambidextrous, not reciprocating, charging system for M 16 and alike rifles, automatic or semiautomatic, capable of operating in tandem with the original rear t charging handle. Such a mechanism array should be capable of being installed in existing rifles as a retrofit kit without requiring any machining or permanent modifications to the original receiver. The gas block assembly composed of two ensemble able parts to facilitate the cleaning and installation procedure; an upper gas block and a lower gas block, which functions like a traditional one piece block when assembled together. A single gas block will also perform properly with the proper characteristics gas passageways. The system having an external lateral, ambidextrous, non-reciprocating, charging handle to be operated when required by the frontal supporting hand for ease of operation. The frontal charging handle capable of coupling with a horizontally sliding frontal hand guard to provide a “Pump Action” charging alternatively when connected to the Floating Charging Handle Cylinder ( 30 ). The linkage system working inside a structural tube to provide rigidity alignment, receive and transmit, energy, motion, and prevent harmonic vibrations. The linkage system having adapting supports to be coupled with existing parts and shapes of the receiver with the proper protrusions and cavities to provide a secure motion constraining fixation means to the rifle. The system should provide an easy manner to disassembly in the field. The system should be dismountable to return the rifle to the factory original condition. The system should be compact enough to preserve the general shape of the rifle without adding significant weight to the rifle. At least one single tube support adaptor plate, by design, must to be preferably coupled with the Barrel nut of the M16 rifle is needed to provide the rear structural tube support. At the front, preferably, though not necessarily, the gas block provides the complete support to the system. The system may be completely reversible and retrofit in M16 standard rifle platforms and others conveniently adapted.
[0174] The combination of several elements interacting together is what makes this invention remarkable and unexpected. All previous direct drive gas piston systems to replace the gas impingement system have rods or bars, which at some point operate in cantilever supported only by a portion penetrating inside the receiver without any other support which generates disturbing harmonic vibrations affecting the performance of the system and demanding thicker sections of the bar. This invention utilizes a structural supporting Guide Tube ( 70 ) to contain and constrain laterally the displacement of all mechanisms within. Especially important it is for the Push Rod ( 80 ) which has a Cylindrical Ring ( 80 A) sliding internally with proper tolerance against the internal diameter surface of the supporting tube ( 70 ). Such contact is unique to this design since all others lack of any structural tube which provides alignment and support necessary to prevent the lateral harmonic vibration. By having a permanent lateral contact with the tube the push bar never is in cantilever support. It is important to this invention to provide a rigid Guide Tube ( 70 ) to grant support, containment and alignment to most of its components. A Tube Support Adapting Plate ( 10 ) of unique shape and design to couple with the receiver or parts attached to it is a non permanent means of securely affixing and constraining the Guide Tube ( 70 ) to the rifle at the rear, without interfering the action or altering its integrity. At the front, the Guide Tube ( 70 ) is affixed, and constrained to rotation or linear horizontal displacement, to the rear wall end of the Gas Block ( 65 ), which in turn is securely affixed to the barrel by means of the Barrel Bore Clamp ( 65 B). A Floating Charging Handle Cylinder ( 30 ) array operates sliding inside said Tube Guide ( 70 ) in conjunction and complete independence of the parts involved in the direct drive action. A Main High Pressure Expansion Chamber ( 20 D) of the Floating Gas Cylinder ( 20 ) has a “Sine qua non” (impossible to do without) requisite of necessary importance in attaining the required momentum to force the Bolt Carrier ( 13 ) to its most rearwards position to extract the used case and load a new round from the magazine. Without the Expansion Chamber ( 20 D) the impacting force of the Direct Drive gas System may not be strong enough to force the displacement of the Bolt Carrier and Bolt inside the rifle receiver. No permanent modification of the M-16 rifle or AR 15 platform rifles is needed to install this kit, condition which makes possible the reverse procedure of uninstalling the kit, leaving the rifle in an original state. In this invention, in a certain embodiment the gas block device can be constructed as a single unit piece, using part ( 65 ), or, in another embodiment as a two piece gas block, so that when assembled together the Lower gas block ( 60 ), and the Upper Gas Bolt ( 50 ), both become a unit that exactly matches the one piece gas block ( 65 ). The two piece gas block facilitates the complete disassembly procedure for cleaning of the gas system more thoroughly. The Upper Gas Bolt ( 60 ), slides completely muzzlewards allowing the complete removal of the all the parts of the Direct drive gas piston system, and those of the lateral front charging system.
[0175] The following description for Assembly is made when utilizing the One Piece Gas Block ( 65 ). To assemble, in one of the possible embodiments, proceed as follows: Remove front OEM hand guards from the rifle. Remove the existing OEM gas block and front sight or from the rifle. Remove existing OEM gas impingement tube. Then from the muzzle end introduce the rifle barrel through the Annular Barrel Bore ( 1011 ) of a Tube Support Adapting Plate ( 10 ) with a Tube Supporting lug ( 11 ) facing foreword. Then press The Rear Pins ( 10 A) of the Tube Support Adapting Plate ( 10 ) against a Semi Circular Cuts ( 12 A) of a Barrel Nut ( 12 ). Then introduce the Locking Protrusions ( 70 D) of a Guide Tube ( 70 ) inside an Annular Insertion Cut ( 11 A) of said Tube Supporting lug ( 11 ) assuring that the Engaging Groves ( 70 A) are placed to the side of preference where the Lateral Charging handle ( 30 A) will be operating. Then, introduce a Compression Spring ( 90 ) inside said Guide Tube ( 70 ) from the Fore End ( 70 B). Then, introduce the Rear End Push Rod ( 80 B) through said Compression Spring ( 90 ), and continue introducing a Push Rod Push Rod ( 80 ) through the Rod Bore Guide ( 11 B) of said Tube Supporting lug ( 11 ), Then Introduce the Rear Cylindrical Cavity ( 20 E) of a Floating Gas Cylinder ( 20 ) through the Fore End ( 70 B) assuring that a Lateral Alignment Guide ( 20 A) slides through the Engaging Groves ( 70 A) and that the Fore End Push Rod ( 80 A) penetrates inside Rear a Cylindrical Cavity ( 20 E). A Cylindrical Ring Push Rod ( 80 C) should move freely through the Internal Wall of the supporting Tube ( 70 E); Then, Introduce a Floating Charging Handle Cylinder ( 30 ) inside said Fore End ( 70 B) assuring that Pivot Hole ( 30 C) is placed towards the muzzle end, and that Center Bore ( 30 B) slides into a Slim Portion ( 20 F) of Floating Gas Cylinder ( 20 ). Then introduce the muzzle end of the barrel through a Barrel Bore Clamp ( 65 A) of a One Piece Gas Block ( 65 ) assuring that Retention a Spring Bore ( 65 G) faces towards the muzzle end. Slide said One Piece Gas Block ( 65 ) rearwards so that the Rear Face ( 65 K) contacts the step on the Barrel ( 14 ), close to the Barrel Gas Port ( 14 A), and aligns with a High Pressure gas Aperture ( 65 B); also make sure that Fore End ( 70 B) penetrates inside the Undercut for Tube Support ( 65 C) of One Piece Gas Block ( 65 ). Place the Retention Spring ( 65 J) inside said Retention Spring Bore ( 65 G). Fore End of a Retention Spring ( 65 J) will go inside a Locking Dimple ( 406 ) to secure rotation of a Gas Plug Piston Regulator ( 40 ). Introduce said Gas Plug Piston Regulator ( 40 ) through a Gas Plug Piston Regulator Bore ( 65 E) assuring that the External Knob ( 40 C) penetrates inside Internal Cylindrical Cavity ( 20 C) of a Floating Gas Cylinder actuator ( 20 ). Push said External Knob ( 40 C) rearwards and insert a Securing Rod ( 51 ) through a Securing Rod Bore ( 65 F) and place two Retaining Pins ( 51 A) on a Retaining Slot ( 51 B). Align Upper Face ( 65 H) with the horizontal top of the rifle by rotating One Piece Gas Block ( 65 ) to assure alignment of Barrel ( 14 ) with High Pressure gas Aperture ( 65 B). Insert Screw ( 65 I) through Screw Holes ( 65 D) and tighten. The above description is based in the utilization of One Piece Gas Block ( 65 )
[0176] Two different systems operate jointly in cooperation without interfering in any instance of the independent operations: A gas piston system, and an external linkage mechanism, manually actuated, charging system.
[0177] The operation of the direct drive gas Piston-Cylinder system is of pneumatic (gas) nature where dynamics of gases apply, forcing mechanical dynamics to apply also. In one of the possible embodiments of this invention the gas block device can be constructed as a single unit piece, using the one piece gas block part ( 65 ). In another possible embodiment a two piece gas block assembly is possible, in a manner that when assembled together, the upper gas block part number ( 50 ) and the lower gas block part number ( 60 ), both become a unit that exactly matches the one piece gas block ( 65 ). For disassembly, the lower gas block part number ( 60 ) remains attached to the barrel, and the upper gas block part number ( 50 ) slides muzzlewards facilitating the fast complete disassembly procedure for thoroughly cleaning all the components of the gas system, as well as the frontal cocking charging system.
[0178] The following description is based in the alternative utilization of a Two Piece Gas Block. Parts ( 50 ) and ( 60 ) assembled together. In the direct drive Gas Piston operation, the non reciprocating Lateral Exterior Charging handle ( 30 A) and the Floating Charging Cylinder ( 30 ) do not intervene at all. They are completely independent. After igniting the powder of the cartridge, the projectile moves through the bore of a Barrel ( 14 ) in response to the high pressure propellant gases. Immediately after passing a Barrel Gas Port ( 14 A), a portion of the high pressure gasses diverts out of the barrel through a High Pressure Gas Aperture ( 60 B) of a Lower Gas Block ( 60 ), which aligns with a High Pressure Gas Aperture ( 50 C) of a Upper Gas Block ( 50 ), which is aligned with a Lateral Regulating Radial Apertures Array ( 40 D) of a Gas Plug Piston Regulator ( 40 ), which conveys the high pressure gases to the Gas Injection Passage ( 40 E). The Exhaust Portion ( 40 E) of the Gas Plug Piston Regulator ( 40 ) penetrates inside the Internal Cylindrical Cavity ( 20 C) of the Floating Gas Cylinder ( 20 ), allowing the high pressure gasses to penetrate into the Main High Pressure Expansion Chamber ( 20 D), which has a larger diameter ( 20 J). The high pressure gasses act over the rear face ( 20 H) of the Main High Pressure Expansion Chamber ( 20 D) with a force described by the equation F=P×A where P is the high pressure of gasses inside Main High Pressure Expansion Chamber ( 20 D) multiplied by the rear area (A) of the Main High Pressure Expansion Chamber ( 20 D). This forces the Floating Gas Cylinder ( 20 ) to move rearwards impacting Fore End Push Rod ( 80 A) of Push Rod ( 80 ) which is nested inside Rear Cylindrical Cavity ( 20 E), causing the Rear End Push Rod ( 80 B) to ram against the Bolt Carrier Key ( 13 A) of the Bolt Carrier ( 13 ), which in turn displaces rearwards compressing the main spring inside the receiver ejecting the empty case, and in a reciprocating forward movement displaces a new live round from the magazine forcing it into the Barrel ( 14 ) chamber, thus completing the automatic firing loading cycle. The Compression Spring 90 forces the Push Rod ( 80 ) forward back into the Rear Cylindrical Cavity ( 20 E), and Exhaust Portion ( 40 A) completely coupled into Internal Cylindrical Cavity ( 20 C).
[0179] It must be understood that the Gas Plug Piston Regulator ( 40 ) is housed inside the gas plug piston regulator bore ( 50 D) of the Gas Block ( 50 ) and remains immobile horizontally, but can be rotated to regulate the high pressure gasses flow. The Gas Plug Piston Regulator ( 40 ) has an array if several Lateral Regulating Radial Apertures Array ( 40 D) of different diameters that align with High Pressure Gas Aperture ( 50 C) and constrains and conduct the high pressure gasses flow into Gas Injection Passage ( 40 E), and ultimately to the Main High Pressure Expansion Chamber ( 20 D) where there is a rear wall of larger projected area over which the high pressure acts producing a strong force in the rearwards direction which is transmitted to the Push Bar ( 80 ) displaces rearwards together with the floating Gas Cylinder Actuator ( 20 ) When the Exhaust Port ( 20 B) of Floating Gas Cylinder ( 20 ) aligns with Gas Plug Rear Face ( 40 H) the high pressure gasses are relived and expelled to the exterior through an Exhaust Port ( 201 ) passing through the Engaging Groves ( 70 A) of the Guide Tube ( 70 ). The Lateral Alignment Guide ( 20 A) slides by the Engaging Groves ( 70 A) maintaining permanent alignment of the Exhaust Port ( 20 B) with the Engaging Groves Engaging Groves ( 70 A) and allowing the longitudinal displacement of Floating Gas Cylinder ( 20 ), while constraining any rotation, thus assuring the unrestricted flow of the gasses through the Engaging Groves ( 70 A) to the exterior. The Floating Charging Handle Cylinder ( 30 ) remained immobile during the above described action resulting in a non reciprocation act due to the sufficient clearance of the internal wall of The Floating Charging Handle Cylinder ( 30 ), and the external wall of the slim portion ( 20 F) of the Floating Gas Cylinder Actuator ( 20 ).
[0180] The operation of the Frontal lateral Ambidextrous, non reciprocating charging system is of mechanical nature only. When the firer manually pulls an Articulated Handle Extension ( 30 D) rearwards it acts over a rear face surface ( 30 F) having an annular shape which contacts the Front Annular Face ( 20 G) of the Floating Charging Handle Cylinder ( 30 ) producing a rearwards force and a displacement. A Center Bore ( 30 B) of Floating Charging Handle Cylinder ( 30 ) slides loosely out of the Slim Portion ( 20 F) of the Floating Gas Cylinder ( 20 ), and slides inside the Internal Wall of the Tube ( 70 E), and the Lateral Charging handle ( 30 A) displaces linearly only along the Engaging Groves ( 70 A). The Floating Charging Handle Cylinder ( 30 ) is a part independent of the direct drive impingement action. It has a spring loaded Articulated Handle Extension ( 30 D) that pivots about the Pivoting Pin ( 30 E) to provide a larger cocking handle to ease the rearwards pulling of the firer for cocking. At that moment the Rear Face ( 30 F) of Floating Charging Handle Cylinder ( 30 ) contacts and pushes the Annular Face ( 20 G), This forces the Floating Gas Cylinder ( 20 ) to displace rearwards pushing Fore End Push Rod ( 80 A) of Push Rod Push Rod Push Rod ( 80 ) which is nested inside Rear Cylindrical Cavity ( 20 E), causing the Rear End Push Rod ( 80 B) to move against the Bolt Carrier Key ( 13 A) of the Bolt Carrier ( 13 ), which in turn displaces rearwards compressing the main spring inside the receiver ejecting the empty case. When releasing the Articulated Handle Extension ( 30 D), the compressed main spring of the rifle forces the bolt carriage forward and in a reciprocating forward movement displaces a new live round from the magazine forcing it into the Barrel ( 14 ) chamber, thus completing the cocking action. The Compression Spring ( 90 ) assists in the return of the Rod Push Rod ( 80 ), Floating Gas Cylinder ( 20 ), and the Floating Charging Handle Cylinder ( 30 ) to the frontal position.
[0181] The Guide Tube ( 70 ) is necessary to provide internal alignment, anti rotation, protection from dirt, and to serve as ground to all the linkage mechanism components functioning within. The Guide Tube ( 70 ) is locked in position constraining lateral, longitudinal or rotational movements by Rear End ( 70 C) at the rear Guide Tube ( 70 ) that couple with a Annular Insertion Cut ( 11 ). A conveniently placed on a Tube Support Adapting Plate ( 10 ), and at the front the Guide Tube ( 70 ) is supported by insertion on a Undercut for Tube Support ( 50 B). The Annular Insertion Cut ( 11 A) are placed at 180 degrees so that the Rear End ( 70 C) can be engaged in a manner that the Engaging Groves ( 70 A) is placed either to the right of the rifle or to the left, Thus assuring an ambidextrous operation according to the preference of the firer.
[0182] This invention has as well similar applications, in other possible embodiments, for rifles different from standard M16, M4 platforms, utilizing a conventional unitary gas block with a self-contained short stroke gas piston-cylinder coupling actuator, in which either the piston or the cylinder move backwards to impact and to transmit energy and motion to a push bar, operationally linked to the Bolt Carrier in which there is not a Floating Gas Cylinder Actuator ( 20 ) or functionally equivalent part which moves linearly in a Short Stroke mode, when moved by the effect of high pressure gases, or in a Long Stroke mode, when moved by the effect of a manual external mechanical force.
[0183] The M 16 rifle has proven to be an extraordinary rifle under many combat circumstances. This invention makes the M16 even better. Accordingly, it should understood that the invention described herein remedies the two most prominent remaining flaws of the M 16 family of rifles in one single addition to new rifles or as a retrofit kit for existing rifles. The M16 has evolved and undergone several revisions and upgrades which have brought it to be considered outstanding due to its reliability, accuracy and performance. Several attempts have been made by the governments and private rifle developers to present a substitute weapon to be adopted by the military, but none up to now is more advantageous than the presently produced M-16/M4. In addition, the AR-15 family of rifles produced and sold as a civilian version of the M-16 also benefits from the present invention which is totally compatible with its design for factory installation in new rifles produced or for retrofit installation by individual owners. However the major benefits of this development are in the tactical improvement represented, in drastic time reduction of the charging operation, reduction of body movements, protection of the shooter location concealment, drastic reduction of time to get back on target, it favors the use of more powerful scopes, it conveys more fire power and accuracy. The weight addition is very small, the manufacturing cost is low, and the retrofit operation is very simple. This innovative device has the potential of extending the life of service of the M16 rifle in the military or to be used for the next generation of rifles to be put in service in the future.
[0184] The operational system described in the present application enables the independent manual mechanical rear displacement to the rear of the Floating gas cylinder actuator, transmitting the motion to the push bar and ultimately displacing the bolt carrier rearward for manual charging operation, which in all previous art design is moved pneumatically by the action of the expelled gasses utilizing a gas piston system only. The frontal location of a charging handle provides significant operating ergonomic benefits to the shooter reflected in comfort, precision, reduced time to get back on target, and ultimately, increased survival chances when performing in crucial situations when reaction time is extremely important.
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An Operating System for firearms combining a direct drive gas piston system, functioning in conjunction with a linkage mechanism operating within a structural tube, enabling the use of a frontal charging handle or a sliding handguard allowing a frontal actuated, ambidextrous, non-reciprocating charring operation. The operating system is conceived to be easily retrofitted in M16 rifles without performing any machining operations. The artifact partially comprises affixing supports, a structural tube to constrain and align the actuating components, a securing frontal gas block, a regulated direct gas piston including an independent push bar with alignment rings, springs, and freely displacing parts with lateral projections connecting with the exterior handle or hand guard actuator. By enabling to use the firer's supporting hand while charging, it solves complicated ergonomic maneuvers required to charge with the original M16 T handle, improves rifle cleanliness, and reduces the crucial time to get back on target.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/GB2007/000126, filed Jan. 4, 2007, which claims priority to Great Britain Application Serial No. 0600878.3, filed Jan. 17, 2006, which are incorporated herein by specific reference.
BACKGROUND OF THE INVENTION
[0002] 1. The Field of the Invention
[0003] The invention relates to wiring and in particular but not exclusively to in-vehicle wiring. The kind of vehicle envisaged may be selected from a wide range of vehicles from military vehicles such as tanks, to sport motors, rail, ice, air, water, and snow going vehicles.
[0004] 2. The Relevant Technology
[0005] One prior art known is a flat carbon fiber case or box housing multiple wires such as those currently used in Formula One racing. In order to manufacture these boxes, the box is initially formed by molding carbon fiber faces of the box and joining them together and thereafter loosely placing the wires in their required position dependent upon the manufacturing specification. A drop of silicon or other sealant is then used to secure the lid of the box in place once the wires are installed within the box.
[0006] The following drawbacks exist in this prior art structure:
the wires can displace within the box due to vibration, impact, explosions or other outside occurrence; these boxes which are essentially rectangular parallelepipeds are neither able to snugly fit around nor able to be placed on objects other than objects which are themselves flat; there are spaces between wires and between the faces of the box signifying that the strength of the box itself is reduced as each face if acted upon can separately bow; it requires the use of silicon or other sealants to secure the components together; and air fills any remaining space in the box which may cause corrosion within the box if corrosive components are contained in the box.
[0012] The following patent documents are acknowledged U.S. Pat. No. 6,971,650; DE10308759A1; EP1506553; US2006/000924; US2004/0069525; EP1376618A3; PCT/EP03/01531; WO03/098642; U.S. Pat. No. 6,419,289; DE29917502; EP1026019; U.S. Pat. No. 5,371,324; De354516; EP0208138; and U.S. Pat. No. 3,168,617.
SUMMARY OF THE INVENTION
[0013] In a first broad independent aspect, the invention provides an array of multiple wires; one or more connectors which engage said wires; two or more layers of a hardened fiber and filler compound sandwiching said wires; the areas adjacent to the wires comprise a filler which immobilizes the wires relative to said layers; wherein at least a portion of said connectors is embedded in a filler.
[0014] This configuration is particularly advantageous because it allows the connector portions to be protected at their rear and ready for use at their front. This allows them to be an integral part of the connector and wires assembly. It also may be readily formed into a generally flat structure between the connectors in order to fit in confined spaces.
[0015] In a second broad independent aspect, the invention provides a wiring component comprising an array of multiple wires sandwiched between two or more layers of a hardened fiber and resin compound where the areas adjacent to the wires are filled by filler such as the resin or the resin and fiber compounds which immobilizes the wires relative to said layers; wherein the fibers are woven.
[0016] This configuration is particularly advantageous because it provides a particularly rigid structure and marks a complete departure from prior art non-woven teaching which results in components which are inherently flexible.
[0017] In a third broad independent aspect, a wiring component comprises an array of multiple wires sandwiched between two or more layers of a hardened fiber and resin compound where the areas adjacent to the wires are filled by a filler such as the resin or the resin and fiber compounds which immobilizes the wires relative to said layers; wherein the wires comprise copper and are sheathed with one or more sheaths which create a bond between the wires and layers.
[0018] This configuration is particularly advantageous because the sheaths themselves can contribute to the bonding of the wires with the layers.
[0019] In a fourth broad independent aspect, the invention provides a wiring component comprising an array of multiple wires sandwiched between two or more layers of a hardened fiber and resin compound where the areas adjacent to the wires are filled by a filler such as the resin or the resin and fiber compounds which immobilizes the wires relative to said layers; wherein the component incorporates a substantially planar portion and a lip extending from said planar portion at an angle. This configuration is particularly advantageous because it adds rigidity to the component and allows it to fit over a three dimensional object such as an engine.
[0020] In a subsidiary aspect in accordance with the invention, the connector incorporates a cap protecting its connectable portion; wherein said cap incorporates a seal on the inside of said cap. This configuration is particularly advantageous because it prevents the connector being damaged by filler flowing into the connectable portion.
[0021] In a further subsidiary aspect, the fibers are woven. This allows the layers to be strengthened.
[0022] In a further subsidiary aspect, the wires comprise copper and are sheathed in one or more sheaths which create a bond between the wires and layers.
[0023] In a further subsidiary aspect, the component incorporates a substantially planar portion and a lip extending from said planar portion at an angle.
[0024] In a fifth broad independent aspect, the invention provides an array of multiple wires sandwiched between two or more layers of a hardened fiber and resin compound where the areas adjacent to the wires are filled by the resin or the resin and fiber compounds which immobilizes the wires relative to said layers.
[0025] This configuration is particularly advantageous because it achieves an air free or almost air free protective box. It also provides all the advantages of a conventional carbon fiber box in that it is a solid structure with the toughness and the heat resistance of the traditional boxes. The array can be molded in a form to fit the shape of the body of a vehicle. This would therefore have the additional benefit of reducing the overall size requirement around an engine which can lead to a reduced size of body with less wind resistance than would otherwise be the case. It avoids any displacement of the wires relative to each other during use and installation of the wires within a receiving system. This configuration does away with the requirement for using silicon or other sealants and will therefore simplify the manufacturing process. This system may be used in a wide variety of applications which may include for example substituting traditional circular in cross-section sheathed heat resistant engine to chassis electrical multiple wire cables.
[0026] In a further subsidiary aspect in accordance with the invention's fifth broad independent aspect, the wires are substantially co-planar when viewed in a cross-section across the width of the wires. This marks a complete departure from the prior art teaching in circular cross-section cables. It would allow flat and curved wire arrays to be achieved which would provide the wire arrays with greater flexibility in terms of use whilst retaining the advantages of toughness and heat resistance associated with the prior art devices.
[0027] In a further subsidiary aspect, the compound is a non-conductive compound. This may for example be a compound of a material similar or identical to the material sold under the brand or designation “Kevlar” which would permit either the wires to be provided without any protective sheaths, if desired, or in the case of the melting of wire sheath of still retaining electrical insulation of the wires thus avoiding short circuits or other potentially dangerous consequences.
[0028] In a further subsidiary aspect, the two or more layers of compound are employed on either side of the multiple wires. The use of multiple layers allows a flat smooth surface to be produced rather than one which follows precisely the contour of the enclosed wires and would therefore be uneven above the wires. This optional configuration would therefore allow the wires to be disguised within the layers. It also reduces the stress/strain concentration points which would be located at these uneven regions of the surfaces when only one layer is used on both sides of the wires. It therefore offers a tougher and therefore more durable configuration than would otherwise be achieved.
[0029] In a further subsidiary aspect, the wires are sheathed in addition to said compound by a sheath which is resistant to 100 degrees in a vacuum oven. This particular kind of sheathing allows the wires to remain protected, immobilized and conductive only across the wires (i.e., without any risk of a short circuit in normal operation).
[0030] In a further subsidiary aspect, the array is rigid and molded to conform to the shape of a vehicle component. This particularly allows when the vehicle component is the vehicle body to save space within the vehicle body so that a vehicle body of a small size may be used which would have important benefits from a wind resistance point of view.
[0031] In a sixth broad independent aspect, the invention provides a method of producing an array of multiple wires, comprising the steps of:
selecting a plurality of wires placing them between layers of a hardenable fiber and resin compound; vacuuming air from the array; and heat treating the array in a vacuum oven.
[0035] When this method is employed there is no complex post-hardening assembly required. The air is effectively removed from interstitial positions between the wires. Any given shape may be obtained by preferably placing the wires and the compound in a mold. This would allow compliance with any selected object for attachment. The product resulting from this method incorporates any of the advantages listed above with reference to previous specific aspects.
[0036] In a seventh broad independent aspect, the invention provides a method of producing a wire component, comprising steps of:
selecting a plurality of wires placing them between layers of a hardenable fiber and resin compound; vacuuming air from the array; placing the layers and wires on a mold; and heat treating the array in a vacuum oven.
[0041] In a subsidiary aspect in accordance with the invention's seventh broad aspect, the invention provides the step of attaching a connector to said wires and clamping said connector to said mold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Various embodiments of the present invention will now be discussed with reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope.
[0043] FIG. 1 schematically shows the assembly prior to heat treating.
[0044] FIGS. 2 a and 2 b show cross sectional views of an array of multiple wires with one layer on both sides of the wires.
[0045] FIGS. 3 a and b show cross sectional views of the array of multiple wires with two layers on both sides of the wires before and after treatment.
[0046] FIG. 4 shows in perspective view an end portion of an arc-shaped band of multiple wires where the band itself is rigid.
[0047] FIG. 5 shows a cross sectional view of a wiring component located in a mold.
[0048] FIG. 6 shows a perspective view of the mold with its connector clamp in position.
[0049] FIG. 7 shows a perspective top view of a portion of the mold without its connector portion in place.
[0050] FIG. 8 shows a perspective view from the front where a connector would be located.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] FIG. 1 shows a lower layer 1 of fiber and resin compound prior to any heat treatment. The fiber and resin compound is formed as a sheet of interwoven fibers with the strands either extending in one direction or in a direction perpendicular to this direction. A cross-mesh is employed. These resin and fiber compounds are readily available in many formats. This particular resin and fiber compound may be a carbon fiber and resin compound. The natural stickiness of the resin allows the wires such as wire 2 to be placed in any appropriate configuration on the first layer. The second layer 3 may be placed on top of the array of wires and secured thereto.
[0052] The two layers and the wires may be placed on or in a mold which imposes its shape on the component. In order to improve the smoothness of the surface finish a glass or aluminum mold is preferred. An aluminum mold with a surface with a curve will allow the laminate to adopt the shape of that curve following the heat treatment. A station is provided for extraction of the air by vacuum between the layers prior to their placement in an autoclave oven for pressurized (preferably in a vacuum) heat treatment.
[0053] The temperature of the heat treatment is selected in order to strike a good balance between economy and rapidity of heat treatment. For this application however a treatment of approximately 100 to 125 degrees is preferred. After cooling of the component, the array of multiple wires becomes a solid structure with the geometry set by the mold.
[0054] The rigid structure can then be fitted with electrical connectors for incorporation into a vehicle as appropriate. It is also preferred during the heat treatment to continue to remove air from the component in order to minimize any risk of air bubbles in the interstitial regions between the wires.
[0055] FIG. 2 a shows a first layer 4 and a second layer 5 of fiber and resin compound and a number of wires such as wire 6 located between the layers. The wires may be sheathed or unsheathed as appropriate. This arrangement allows the wires to be substantially co-planar when viewed in cross-section across the width of the wires.
[0056] FIG. 2 b shows wire 6 following the heat treatment. The spaces between the wires have now been occupied by resin primarily and potentially fibrous compound which therefore serve to immobilize the wires relative to the layers. Essentially no air is present between the wires. If necessary, prior to the heat treatment additional resin may be spread onto the layers to ensure that the filling between the wires occurs and to create a smoother finished outer surface.
[0057] FIG. 3 a shows the use of two layers on both sides of the wires. These are referenced 7 , 8 , 9 and 10 respectively.
[0058] Following heat treatment the interstitial regions between the wires have been substantially filled and the upper and lower surfaces 11 and 12 are smooth to mirror the smoothness of the aluminum mold or glass mold (two sheets of glass) which may be used to form a component during its preparation and hardening process. The mold may be a single sided mold.
[0059] FIG. 4 shows an arc-shaped component 13 comprising an array of multiple wires sandwiched between two layers of hardened fiber and resin compound. The array of multiple wires is referenced 14 . At one end 15 of the array of multiple wires, two sets 16 and 17 of wires protrude each joining their own individual connector 18 and 19 . The connector illustrates is a standard circular connector. The arc-shaped region has a height of far lesser importance than the diameter of either of these connectors. This allows standard electrical connection to occur from a narrow flat space in a motor vehicle.
[0060] The invention also envisages the use of non-conductive compounds in the layers so that if the sheath of the wires are damaged or melt no short circuit would normally occur. It may also allow no sheath at all to be employed. Layers of Kevlar (brand name or known designation) are for example envisaged.
[0061] The invention also envisages that a layer forms an electrical screen similar to the braiding on electrical cables.
[0062] Furthermore, the wires may have two or more different diameters. The resin and fiber compounds are selected to be able to advantageously conform with a range of wires of different diameters.
[0063] FIG. 5 shows a mold 20 on which is placed a wiring component generally referenced 21 which comprises an array of copper wires located between two layers of hardened fiber and filler compound. Under the vacuum conditions of production, wires and filler paste 22 fill the rear portion of a connector 23 . The connector incorporates a flange 24 which abuts against a connector location plate 25 . The connector location plate 25 incorporates a diameter 26 with a number of indents in order to allow the passage of connector projections 27 . The connector location plate acts as a barrier when it is tightly attached to the mold 20 in order to tend to prevent filler covering the entire connector. For the same effect, there is also provided a connector protective cap 28 which fits tightly over the connectable portion of the connector. A rubber seal 29 is located on the inside of the cap and as the cap is secured to the connector it keeps any filler from entering the connector portions which necessarily are to be kept free of filler for correct electrical connection. Corner 30 is preferably also filled with temporary masking compound to create an extra seal. As can be seen from the figure at arrow 31 the composite material surrounds the rear portion of the connector.
[0064] In FIG. 6 , mold 20 is presented whilst being attached to plate 25 and an upper mold portion 32 which surrounds primarily the connector portion. Connector location plate 25 incorporates a number of indents such as indent 33 allowing the passage of pin 27 of a typical connector. Upper mold portion 32 , plate 25 and mold 20 are joined together by screws which may be placed in bores 34 , 35 , 36 and 37 . Threaded tunnels are provided in upper mold portion 32 and mold 30 to ensure a tight connection between the three components.
[0065] FIG. 6 also illustrates a trough 38 in which the fiber, resin and wires are placed for hardening. The resulting hardened component incorporates a substantially planar portion with said walls such as wall 39 projecting upwards in the mold.
[0066] FIG. 7 shows the trough 38 in greater detail. Before the components are placed in the mold it is preferred to use a release agent. Trough 38 widens out towards the connector portion 40 .
[0067] FIG. 8 is another view of the mold arrangement of FIG. 6 . Identical numerical references are used for clarity.
[0068] The resulting component has a smooth and shiny surface and is preferably comfortable at 130 degrees Celsius.
[0069] The composite material used may be obtained from Advanced Composite Material for example MTM57 CF0300.
[0070] The preferred insulation and conductor kinds are as follows.
[0071] For the insulation sheaths, the following are preferred: PTFE; Polyalkene/PVDF dual wall; Polyimide; ETFE, HSTF; FEP; TFE.
[0072] With regards to the conductor material types, the following are preferred: Copper; Tin-plated copper; Silver-plated copper; Nickel-plated copper; Silver-plated copper alloy; Nickel-plated copper alloy.
[0073] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all resects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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A wiring component includes an array of multiple wires, at least one connector which engages the wires, and at least two layers of a hardened fiber and a filler compound that sandwiches the wires. The areas adjacent to the wires include a filler which immobilizes the wires relative to the layers. In one embodiment at least a portion of the connector is embedded in the filler.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a horse riding exercise machine, and more particularly, to a horse riding exercise machine which can be operated without power and can be adjusted suitable for weight and height of a user.
2. Description of the Related Art
Recently, the number of obese people, from children to adults and regardless of sex, is rapidly rising due to rapid westernization of dietary life and lack of exercise. The rapid rise in the number of obese people is having an enormously bad influence nationally, socially and individually. Obesity has become a social epidemic, and exercise has been the easiest method as the solution of obesity for obese people.
Specifically, an obese person makes efforts to get rid of obesity through methods of walking without using a separate exercise machine and methods of using an exercise machine such as a treadmill to break down the fat in the body, which brings about obesity.
However, these typical exercise methods are monotonous and tedious regardless of whether using the exercise machine or not, so obese people easily give up and so these methods are not a big help for getting rid of obesity.
In addition, horse riding is an exercise having an unusual characteristic in which the rider is required to be in unity with a living horse, is a sport which trains the body and enlivens one's spirit by fostering chivalry, and is an exercise of the whole body which helps to properly develop the body and develop boldness and sound thinking abilities.
In addition, the horse riding is an exercise of the whole body, which can be enjoyed by men and women of all ages, and the horse riding is an exercise performed by straightening one's back such that one's posture is corrected. The horse riding can strengthen intestinal function when seating on a horse, which is moving up and down, is helpful for alleviating constipation for women and students, is effective in prostatic diseases for men, improves lung capacity and is helpful for strengthening the lower body such as calves or thighs.
Therefore, when horse riding, the upper body is straightly corrected, the waist becomes flexible, mental concentration and body rhythm are built, lung capacity is improved, the hip is strengthen, one's courage is developed, and the sense of balance and flexibility of each part of the body are developed to help properly develop a healthy body.
The fact that outstanding effects of the exercise of the whole body can be achieved through horse riding is widely known, however, majority of people cannot actually enjoy horse riding because of economic situations, locations and time.
SUMMARY OF THE INVENTION
Meanwhile, due to the reasons described above, various horse riding machines have been proposed so that horse riding may be enjoyed in narrow spaces such as an indoor, however, typical horse riding machines are driven by motors so noise occurs indoor and energy is consumed.
In addition, the horse riding machines according to typical technologies may not be adapted according to heavy adults or light teenagers, and specifically, may not be adapted according to height.
Therefore, the present invention is provided to solve the described problems, and an object of the present invention is to provide a horse riding exercise machine which can suppress noise occurring indoor, fundamentally prevents energy consumption, and appropriately adapt according to weight and height of the user.
To achieve the object of the present invention, according to an aspect of the present invention, a horse riding exercise machine includes: a body frame having a box shape; a saddle support spaced apart from a central upper part of the body frame in an upward direction by a predetermined distance to support a saddle; a pair of upper support brackets mounted on atop surface of the body frame while facing each other; a shaft coupled by the upper support bracket; an operation frame having one end rotatably coupled to the shaft; a pair of operation rods having ends parts rotatably coupled to an end part of the operation frame and opposite end parts rotatably installed to both side surface parts of a rear part of the saddle support; a lower support bracket installed at a lower part of the body frame; a coupling bar rotatably coupled to the lower support bracket; a coil spring having one end coupled to the coupling bar; a T bar formed in a “T” shape and having one end coupled to the lower support bracket; an elevation rod having one end coupled to the T bar and an opposite end coupled to the saddle support; a forward-backward rod rotatably installed on the saddle support and having one end installed to a lower part of a handle; a link rod having one end rotatably installed at a lower part of the handle and an opposite end rotatably installed at the saddle support; a first bar coupled to the forward-backward rod to interwork with the forward-backward rod and having one end rotatably installed at a front part of the saddle support; a second bar having one end rotatably installed at a rear part of the saddle support; a first rod having one end rotatably coupled to a lower end part of the first bar; a second rod rotatably coupled to the first rod; a third rod rotatably coupled to the second rod; a vertical bar having an upper end part rotatably coupled to a part at which the second rod and the third rod are coupled; a movable bar rotatably coupled at a rear end of the operation frame; a second flywheel coupled to a lower end part of the movable bar by a link to rotate through an elevation of the movable bar; a first flywheel interworking with the second flywheel by a belt; a lower bar rotatably installed at a lower end part of the vertical bar; a rotation frame having one end rotatably installed at the lower support bracket and an opposite end in a form of a free end; a main spring having one end fixed to the operation frame and an opposite end seated on a top surface of the rotation frame; a gear box installed in an inner space of the body frame and provided therein with a worm and a worm gear; a handle installed outside the body frame to rotate the worm of the gear box; and a rotation rod having one end coupled to the worm gear inside the gear box and an opposite end installed to the rotation frame to rotate by an operation of the handle.
According to the present invention, the horse riding exercise machine further includes an indication bar having one end fixed to the rotation frame and an opposite end protruding out of the body frame such that the opposite end protruding out of the body frame elevates according to an elevation of the rotation frame.
In addition, the horse riding exercise machine further includes a foot support at both side surfaces of the saddle.
Further, the foot support includes an inclined frame inclined downward; and a plurality of support bars spaced apart from the inclined frame by a predetermined distance.
According to the present invention, at least one of the support bars is foldable by a hinge.
In addition, the coupling bar interworks with the T bar.
According to the embodiment of the present invention, the horse riding exercise machine is driven without a motor and without power by using energy stored in the flywheel so noise from the motor or a drive apparatus indoor can be suppressed and energy consumption can be prevented, and, specifically, the horse riding exercise machine can be adjusted to fit the weight of the user by using the handle and the foot support can be used according to the height of the user.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing main parts of a horse riding exercise machine according to an embodiment of the present invention.
FIG. 2 is a rear perspective view showing the main parts of the horse riding exercise machine shown in FIG. 1 .
FIG. 3 is a perspective view showing the main parts.
FIGS. 4 and 5 are rear perspective views showing the main parts of FIG. 3 .
FIGS. 6 and 7 are views for explaining a main spring and a coil spring.
FIG. 8 is a side view of the horse riding exercise machine.
FIGS. 9 and 10 are side views of the main parts.
FIG. 11 is a rear view of the main parts.
FIG. 12 is a view for explaining an adjustment according to weight.
FIG. 13 is a view for explaining a handle and an indication bar.
FIG. 14 is a view for explaining a foot support.
FIGS. 15 and 16 are views showing the horse riding exercise machine according to another embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described with reference to accompanying drawings, and same reference numbers are used for same parts in every drawing.
FIG. 1 is a perspective view showing essential parts of a horse riding exercise machine according to an embodiment of the present invention, and FIG. 2 is a rear perspective view showing main parts of the horse riding exercise machine.
As shown in the drawing, the horse riding exercise machine according to the present invention designated as reference number 10 includes, a body frame 11 having a box shape, and a saddle support 13 spaced apart from a central upper part of the body frame 11 in an upward direction by a predetermined distance to support a saddle 100 .
As shown in FIG. 3 , a pair of upper support brackets 17 are mounted on a top surface of the body frame 11 , and shafts 19 are installed at the pair of upper support brackets 17 .
In addition, an operation frame 21 is rotatably installed at a center part of the horse riding exercise machine and has one end rotatably coupled to the shaft 19 (Refer to FIG. 6 ).
Further, a pair of operation rods 23 having end parts rotatably coupled to an end part of the operation frame 21 and opposite end parts rotatably installed to both side surface parts at a rear part of the saddle support 13 are installed (Refer to FIGS. 3 and 5 ).
A lower support bracket 25 is installed at a lower part of the body frame 11 , and as shown in FIGS. 6 and 7 , a coupling bar 55 is rotatably installed on the lower support bracket 25 , and a coil spring 27 is coupled and seated to the coupling bar 55 .
In addition, a T bar 77 formed in a “T” shape is installed at the lower support bracket 25 , and as shown in FIG. 9 , an elevation rod 15 is coupled to the T bar 77 .
The T bar 77 interworks with the coupling bar 55 such that, when the T bar 77 rotates on the lower support bracket 25 , the coupling bar 55 interworks with the T bar and rotates. Therefore, the elastic force of the coil spring 27 influences the T bar 77 and the elevation rod 15 via the coupling bar 55 . One end of an elevating rod 15 is coupled to the T bar 77 and an opposite end is coupled to the saddle support 13 (Refer to FIG. 5 ).
As shown in FIGS. 2 and 3 , a forward-backward rod 51 is rotatably installed on the saddle support 13 and has one end installed to a lower part of a handle 200 . A link rod 52 having one end rotatably installed at a lower part of the handle 200 and an opposite end rotatably installed at the saddle support 13 is installed.
As shown in FIGS. 9 and 10 , a first bar 91 is coupled to the forward-backward rod 51 to interwork with the forward-backward rod 51 and has one end rotatably installed at a front part of the saddle support 13 , and a second bar 92 has one end rotatably installed at a rear of the saddle support 13 .
In addition, a first rod 61 has one end rotatably coupled to a lower end part of the first bar 91 , a second rod 62 is rotatably coupled to the first rod 61 , and a third rod 63 is rotatably coupled to the second rod 62 . Further, a vertical bar 83 rotatably is coupled to a part to which the second rod 62 and the third rod 63 are coupled. In addition, a lower bar 80 is rotatably installed at a lower end part of the vertical bar 83 (Refer to FIGS. 9 and 10 ).
As shown in FIGS. 3 and 9 , a movable bar 71 is rotatably coupled at a rear end of the operation frame 21 , a second flywheel 90 b is coupled to a lower end part of the movable bar 71 by a link 74 such that the second flywheel 90 b is rotated by an elevation of the movable bar 71 , and a first flywheel 90 a is interlocked to the second flywheel ( 90 b ) by a belt 81 .
In addition, a rotation frame 29 is shown in FIG. 10 . One end of the rotation frame 29 is rotatably installed at the lower support bracket ( 25 ) and an opposite end is formed in a form of a free end.
As shown in FIG. 7 , a main spring 31 is seated on a top surface of the rotation frame 29 . The main spring 31 supports the operation frame 21 .
A gear box 35 and a handle 37 is shown in FIGS. 4 and 5 . The gear box 35 is installed at a rear part of an inner space of the body frame 11 , and a worm (not shown) and a worm gear (not shown) are provided in the gear box 35 . The worm and the worm gear decrease the torque, however the embodiment is not limited thereto and other mechanical elements may be used. In addition, a handle 37 is installed outside the body frame 11 to rotate the worm of the gear box 35 .
In addition, as shown in FIG. 12 , a crank 36 is coupled to the worm gear in the gear box 35 , and the crank interworks with the rotation frame 29 by the rotation rod 33 . Therefore, the user operates the handle 37 to elevate a lower end part of the main spring 31 . As shown in FIGS. 1 and 3 , the handle 37 is installed outside of the body frame 11 so that the user may easily operate the handle 37 .
In addition, an indication bar 39 having one end fixed to the rotation frame 29 and an opposite end protruding out of the body frame 11 is installed such that the opposite end protrudes out of the body frame 11 elevates according to an elevation of the rotation frame 29 .
As shown in FIGS. 1 and 11 , a foot support 41 is installed on a frame of a cover formed at both side surfaces of the saddle 100 , the foot support 41 includes an inclined frame 43 inclined downward and a plurality of support bars 45 spaced apart from the inclined frame 43 by a predetermined distance, and the support bars 45 located at upper positions may be folded by a hinge.
An operation according to the configuration described above will be described below.
In addition, as shown in FIGS. 1 and 2 , the handle 200 allows the body to maintain balance and prevent the body from falling during horse riding and the handle may be pulled and pushed back and forth, respectively, by hand. The handle 200 is in a shape of “U” laid down sideways so that the handle may be gripped by both hands.
When the user pushes the handle to a forward direction by using the center of the body while gripping the handle 200 , the upper end of the forward-backward rod 51 leans forward and is pushed, and the lower end of the forward-backward rod 51 is pushed to a backward direction. One end of the link rod 52 installed adjacent to the forward-backward rod 51 is rotatably installed at the handle 200 and the other end is rotatably installed at the saddle support 13 . Therefore, when the forward-backward rod 51 moves, the link rod 52 also moves, thus the handle 200 moves horizontally.
According to the movement, the first bar 91 and the first rod 61 , the second rod 62 , and the second rod 62 and the third rod 63 move by a joint, and the vertical bar 83 rotates around a center by the movement. The lower bar 80 rotates by a rotation of the vertical bar 83 (Refer to FIG. 10 ).
In addition, when the user pushes the handle forward, the upper end part of the forward-backward rod 51 moves forward, and the lower end of the first bar 91 interworking with the front/rear rod 51 moves backward. When the lower end of the first bar 91 moves backward, the lower part bar 80 moves forward by the vertical bar 83 .
In addition, when the saddle support 13 is elevated by using the weight of the user while the user is seated on the horse saddle 100 , the operation frame 21 rotates around the center by the operation rod 23 . The elevation rotates the second flywheel 90 b coupled to the movable bar 71 by the crank. When the user moves the center of gravity back and forth while gripping the handle 200 , the second flywheel 90 b rotates 360° or more. The torque continues to rotate by inertia, and even when the user is sitting still on the horse saddle 100 , the second flywheel 90 b rotates and elevates the horse saddle 100 .
In addition, the adjustment according to the weight of the user will be described.
As shown in FIGS. 4 and 5 , the handle 37 is installed at a back surface of the body frame 11 . In addition, as shown in FIG. 13 , a long hole is formed next to the handle 37 and an indication bar 39 protrudes through the long hole, and markings are formed according to weight along the long hole.
Therefore, when the user rotates the handle 37 , the rotation rod 33 coupled to the gear box 35 and the rotation frame 29 interworking with the rotation rod 33 are elevated, and the main spring 31 is elevated by the elevating rotation frame 29 . As shown in FIG. 13 , the indication bar 39 also elevates along the markings by the elevating rotation frame 29 .
In other words, when the user rotates the handle 37 and positions the indication bar 39 to a position indicating the weight of the user, the main spring 31 also elevates to apply an elastic force at an appropriate position.
In addition, as shown in FIGS. 1 and 14 , the foot support 41 includes the inclined frame 43 inclined to a lower part thereof and a plurality of support bars 45 spaced apart from the inclined frame 43 at a predetermined distance, and as shown in FIG. 14 , at least one of the support bars 45 may be folded by a hinge 46 .
Therefore, the user may easily get on or get off the saddle 100 by using one of the support bars 45 according to the height of the user.
According to the horse riding exercise machine of the present invention, when the user elevates the saddle support 13 by using the weight of the of the user while sitting on the horse saddle 100 , the operation frame 21 also rotates around a center by the operation rod 23 such that the second flywheel 90 b coupled to the movable bar 71 by a crank is rotated by the elevation.
When the user does not use the weight while sitting on the horse saddle 100 , the second flywheel 90 b is automatically rotated so that the horse riding exercise is possible.
The second flywheel 90 b may be automatically rotated by automatically rotating the first flywheel 90 a interworking with the second flywheel 90 b by the belt 81 .
In this case, as shown in FIGS. 15 and 16 , to automatically rotate the first flywheel 90 a , a motor 150 is fixed to a lower part of the body frame 11 and an electrical driving belt 160 is coupled to a shaft 152 of the motor 150 and coupled to the first flywheel 90 a to rotate the first flywheel 90 a.
According to the present invention, when the user does not use the weight while sitting on the horse saddle 100 , the first flywheel 90 a is rotated by the motor 150 and the electrical driving belt 160 to rotate the second flywheel 90 b interworking with the first flywheel 90 a so that the horse saddle 100 is elevated.
The user may automatically exercise by horse riding through operating the motor 150 , and the motor 150 may be stopped to manually exercise by horse riding when exercising by horse riding through using the weight of the user.
While the horse riding exercise machine according to the present invention has been particularly shown and described by embodiments, it should not be interpreted in any way to limit the scope of the present invention. Therefore, the scope of the present invention is not limited to the described embodiments, but is limited only by the accompanying claims and equivalents thereof, and any alterations equivalent to the accompanying claims are within the scope of the present invention.
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A horse riding exercise machine includes: a saddle support; an operation frame; a pair of operation rods; an elevation rod; a forward-backward rod; a vertical bar; a movable bar; a flywheel; a rotation frame; a main spring; a gear; and a handle. The horse riding exercise machine can be driven without power by using energy stored in the flywheel so noise from the motor and a drive apparatus indoor can be suppressed and energy consumption can be prevented, and, specifically, the horse riding exercise machine can be adjusted suitable for the weight of the user by using the handle and the foot support can be used according to the height of the user.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a 371 of PCT/US02/16889 filed 30 May 2002, which claims benefit of application 60/295,454 filed 1 Jun. 2001.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
In the manufacture of paper from wood, the wood is first reduced to an intermediate stage in which the wood fibers are separated from their natural environment and transformed into a viscous liquid suspension known as a pulp. There are several classes of techniques which are known, and in general commercial use, for the production of pulp from various types of wood. The simplest in concept of these techniques is the so-called refiner mechanical pulping (RMP) method, in which the input wood is simply ground or abraded in water through a mechanical milling operation until the fibers are of a defined desired state of freeness from each other. Other pulping methodologies include thermo-mechanical pulping (TMP), chemical treatment with thermo-mechanical pulping (CTMP), chemi-mechanical pulping (CMP) and the so-called kraft or sulfate process for pulping wood. In all of these processes for creating pulps from wood, the concept is to separate the wood fibers to a desired level of freeness from the complex matrix in which they are embedded in the native wood.
Of the constituents of wood as it exists in its native state, the cellulose polymers are the predominate molecule which is desired for retention in the pulp for paper production. The second most abundant polymer to cellulose in the native wood, which is the least desirable component in the pulp, is known as lignin. Lignin is a complex macromolecule of aromatic units with several different types of interunit linkages. In the native wood, lignin physically protects the cellulose polysaccharides in complexes known as lignocellulosics, and those lignocellulosics must be disrupted for there to be marked enzyme accessibility to the polysaccharides, or to separate lignin from the matrix of the wood fibers.
It has been suggested that biological systems can be utilized to assist in the pulping of wood. A desirable biological system would be one which is intended to liberate cellulose fibers from the lignin matrix by taking advantage of the natural abilities of a biological organism. Research in this area has focused on a type of fungi referred to as white-rot wood decay fungi. These fungi are referred to as white-rot, since the characteristic appearance of wood infected by these fungi is a pale color, which color is the result of the depletion of lignin in the wood, the lignin having been degraded or modified by the fungi. Since the fungi appear to preferentially degrade or modify lignin, they make a logical choice for fungi to be utilized in biological treatments to pulp wood, referred to as biopulping.
Several reports have been made of attempts to create biopulping systems using white-rot fungi on a variety of wood fibers. Previous research has concentrated on a single, or relatively few, species of fungi. The most commonly utilized fungi in such prior systems is the white-rot fungi Phanerochaete chrysosporium , also referred to as Sporotrichum pulverulentum . Other fungi which have been previously used in such procedures include fungi of the genera Polyporus and Phlebia. The prior art is generally cognizant of the fact that attempts have been made to use biological organisms, such as white-rot fungi, as part of a process of treating wood, in combination with a step of either mechanical or thermal mechanical pulping of cellulose fiber.
The use of white rot fungi for the biological delignification of wood was studied as early as the 1950s at the West Virginia Pulp and Paper Company (now Westvaco) (Lawson and Still, C. N. (1957) Tappi J., 40, 56A–80A). In the 1970s Eriksson and coworkers at STFI (Swedish Forest Product Laboratory) demonstrated that fungal treatment could result in significant energy savings for mechanical pulping (U.S. Pat. No. 3,962,033 for an invention by Eriksson et al. (1976); (Ander and Eriksson, K. E., (1975); Svensk Papperstidning, 18, 641) (Eriksson and Vallander, K. E. (1982) Svensk Paperstidning, 85(6), R33–R38). Two sequential biopulping consortia comprised of the USDA Forest Service, Forest Products Laboratory in Madison, Wis. (hereinafter, “FPL”), the Universities of Wisconsin and Minnesota, and 22 pulp and paper and allied companies demonstrated the techno-economic feasibility of biopulping in connection with mechanical refining (Akhtar et al., (1992a), Tappi J., 75(2), 105–109); (Akhtar et al., (1992b) Biotechnology in the pulp and paper industry , (Kuwahara, M. and Shimada, M. eds.) Tokyo, UNI Publishers Company Ltd., p. 545); (Akhtar et al., (1993) Holzorschung, 47(1), 36–40); (Blanchette, R., (1984) Applied & Environmental Microbiology, 48(3), 647–653); (Blanchette et al., (1988) Biomass, 15, 93–101); Leatham et al.(1989) Biotechnology in the Pulp and Paper Industry, 4 th International Symposium , Raleigh, N.C., May 16–19); (Leatham et al., (1990a), Tappi J., 73(3), 249–255); Leatham et al., (1990b), Tappi J., 73(5), 197–200), (Myers et al., (1988), Tappi J., 71(5), 105–108); (Pearce, N. H., et aL) screened 204 isolates of wood decay fungi in bench scale trials for their performance in biomechanical pulping of eucalyptus chips. ( Proccedings 49 th Appita Annual General Conference , Hobart, Tasmania, Australia, 2–7 Apr. 1995, 347–351) Refining energy savings of 40%–50% were obtained with some selected fungi. No strength improvements were reported. Additional developments in biomechanical pulping were described in: U.S. Pat. No. 5,055,159 for an invention by Blanchette, et al. (1991); U.S. Pat. No. 5,460,697 for an invention by Akhtar et aL (1995); U.S. application published as WO 9605362 on Feb. 1, 1996.
Unfortunately, biomechanical processes have only gained limited commercial acceptance, and have not been widely utilized. One of the difficulties has been that most of the prior techniques for utilizing biological techniques for the pulping of paper have resulted in paper which has had only marginal strength increase or is weaker than papers made by more conventional processes.
In fact, while a certain amount is known about the interaction of lignin and cellulose in wood fibers, because of the extreme complexity of the relationships, and the variation in the enzymes produced by varieties of the white-rot fungi, it is not readily possible to predict from the action of a given fungus on a given type of wood whether or not the paper made from wood partially digested with such fungus will have desirable qualities or not. The selection of white-rot fungi for biopulping applications on the basis of selective lignin degradation may seem a rational one, but it has proven to be a poor predictor of the quality of the resultant paper. The exact relationship between the degradation of lignin, and the resulting desirable qualities of paper produced at the end of the pulping process, are not at all clear. Accordingly, given present standards of technology and the present understanding of the complex interaction of lignin and cellulose, it is only possible to determine empirically the quality of paper produced through a given biological pulping process and the amount of any energy savings achieved through such a process.
For reasons set forth above, most of the fungi screened for the biomechanical pulping of one type of wood do not necessarily work well in the biomechanical pulping of another type of wood. All the biomechancial pulping references described above are directed to the biopulping and processing of wood species other than eucalyptus, a very common wood species in many parts of the world and potentially valuable source of pulp for papermaking or other processes. What is needed is a method of processing eucalyptus wood which takes advantage of the cost savings of mechanical pulping techniques without a loss of end product quality one often experiences when using mechanical pulping.
SUMMARY OF THE INVENTION
In the method of the present invention, eucalyptus wood is partially degraded with a culture of the fungus Ceriporiopsis subvermispora , followed by mechanical pulping of the treated wood.
It has been found that through the biological degradation of eucalyptus chips using Ceriporiopsis subvermispora followed by mechanical pulping of the treated wood chips, a dramatic decrease in the energy required for mechanical pulping is achieved while at the same time giving rise to paper which has enhanced, rather than decreased, strength characteristics.
It is thus an advantage of the process described in accordance with the present invention that a procedure for the biomechanical pulping of eucalyptus wood chips is described which utilizes less energy than prior art techniques and which results in paper having more desirable strength characteristics.
It is further an object of the present invention in that it utilizes a natural biological organism to degrade the wood thus reducing the likelihood of unwanted artificial environmental contaminants produced by degradation of lignin and its byproducts.
It is a further advantage of the present invention in that it has been found that the biological processing of the wood chips in accordance with the present invention can be done in a static fermentation procedure without the need for an exotic or moving fermenting chamber thereby allowing the process to be used more practically on a large scale.
Other objects, advantages, and features of the present invention will become apparent from the detailed description of the invention, below.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed toward the biological pretreatment of wood chips for pulp making for paper manufacture. It has been particularly found here that through the use of a particular species of fungus, and the maintenance of relatively forgiving conditions during the treatment of wood chips by said fungus, it is possible to utilize a biological treatment or pretreatment as a part of a process of pulping eucalyptus wood, a wood resource of high commercial importance in many parts of the World. It has further been found that the pulping process results in a paper which has a strength which is increased over paper made from eucalyptus wood by purely mechanical pulping and over paper made from other species of wood by biomechanical pulping. It has been found, furthermore, that the eucalyptus biomechanical pulping method of the present invention results in a dramatic savings in the energy expended during the mechanical pulping process. In other words, the process of biomechanical pulping of eucalyptus wood of the present invention not only results in energy savings; it also results in a stronger product.
This process of the present invention makes use of white rot fungi, preferably, a culture of C. subvermispora , more preferably a culture of C. subvermispora L-14807-SS-3. However, other white rot fungi can also be used. Strains of C. subvermispora can be maintained by conventional fungal culture techniques most conveniently by growing on potato-dextrose-agar (PDA) slants. Stock slants may routinely be prepared from an original culture for routine use and may be refrigerated until used. The particular strain of C. subvermispora utilized in the examples below, L-14807-SS-3 was obtained from the Center for Mycology Research, Forest Products Laboratory, Madison, Wis. It was found that particular strain of fungus was particularly well-suited for biomechanical pulping of eucalyptus wood, according to the process of the present invention. However, other it is contemplated that other strains of C. Subvermispora , such as—CZ-3, L-9186-SP, FP-105732, and FP-105752-SS5, and other white rot fungi, such as Hyphodontia setulosa, Phlebia subserialis, Phlebia brevispora, Phlebia tremellosa, Phanerochaete chrysosporium would be suitable for use in the methods of the present invention.
The process of the present invention is intended for and particularly adapted for the biopulping of eucalyptus. The wood is converted to chips through a conventional technology. Wood chips are heat treated, preferably with steam, to disable but not necessarily sterilize the chips prior to inoculation with the fungus. The moisture content in the chips is kept at fiber saturation point or greater. A preferred moisture content would be approximately 50–55% of the total wood based on wet weight basis of the chips.
Fungi are preferably applied to the wood as follows. To inoculate significant volumes of wood chips, a starter inoculum may be prepared. PDA plates are inoculated from PDA slants and incubated at 27±1° C. and 70–90% relative humidity. These plates are used to inoculate 1 liter Erlenmeyer flasks containing potato dextrose broth and yeast extract. The inoculated flasks are incubated without agitation in an incubator at 27±1° C. and 70–90% relative humidity for 7–10 days. The surface of the medium is covered with the fungus in the form of mat. The fungal mat is removed from the medium, washed with sterilized water on sterilized buchner funnel to remove all the medium. The fungal mat is transferred into a sterile waring blender with sterile forceps and blended with sterile water. This suspension is used to inoculate wood chips. Scaling up the foregoing culture steps for preparing the fungal inoculation involves preparation of media in commercial scale vats, and growth of fungi in commercial scale fermenters. Using industrial scale equipment, fungal cultures in 500–1500 gallon batches are readily obtainable.
Fungal treatment of wood chips is carried in bioreactor which may be any of a number of styles capable of handling solid media fermentation culture. It is merely required that the stationary or solid phase reactor have sufficient aeration so as to ensure adequate O 2 flow to the fungus and significant removal of CO 2 therefrom. In fact, it is an advantage of the process that it can be conducted in static fermentation procedure without the need for an exotic or moving fermenting chamber thereby allowing the process to be used more practically on a large scale. Aeration, humidity and temperature are all preferably controlled, to at least some extent. On an industrial scale, the inoculated chip mass may be incubated in cylindrical silos or in open chip piles of 20–200 tons, under nonstick conditions, provided proper ventilation is maintained, as discussed more fully hereafter.
For the fungal treatment, wood chips are put in the bioreactor, autoclaved and cooled to room temperature, or exposed to steam to disable native microorganism populations without absolute sterilization. The wood chips to be treated are inoculated with starter culture. The amount of inoculum added to the chips can vary. It should be sufficient to ensure growth and spread to all chips in the bioreactor. Inoculum level of 1 to 5 gm per ton of wood chips was found to be sufficient. The chips so inoculated will then be incubated during a time period in which the fungal mycelia will penetrate throughout the wood chips. It has been found that nutrients are not required during fungal treatment of eucalyptus wood chips. Addition of nutrients does not give additional biopulping benefits but result in more loss in the weight of wood chips and unbleached pulp yield. The most desired temperature range depends on the fungal strains.
It has been found that a bioreactor kept in the range of 27±2° C. with a moisture content in the wood of 55–65% achieves a great degree of mycelia penetration of wood chips that results in significant degradation of wood chips for paper pulping process. The wood chips are aerated continuously during the incubation period with the air saturated with moisture that the wood maintains the constant moisture content of about 55–65%. It has been found that under the conditions used experimentally, an incubation period of 1 to 3 weeks results in significant modification of the wood chips and reduction in energy output for mechanical processing in the subsequent processing steps.
The biologically degraded wood chips are then subjected to a mechanical pulping process. Eucalyptus pulp made according to the biomechanical pulping procedure of the present method can then be bleached in a multistage bleaching process and made into paper using standard paper-making techniques. Paper made from eucalyptus biomechanical pulp is better in quality, strength and texture to that created from eucalyputs through a simple mechanical pulping process and to that created from other woods through either simple mechanical or biomechanical pulping processes.
Effective biopulping can be carried out under nonsterile conditions in which naturally occurring flora are present and viable. However, better results are obtained with steamed or autoclaved wood chips. Eucalyptus wood chips are exposed to live steam resulting in elevating their surface temperature to about 90° to 100° C., as measured immediately after steam treatment. The exposure time is a function of the temperature of the superheated vapor and also the inlet pressure. While 101° to 108° C. influent steam at 15 to 75 in line psi for exposure times of 3 to 50 seconds is adequate, the optimum values are best determined in a few empirical process runs for the particular type and configuration of equipment, as hereinafter described in more detail.
The chamber in which steam treatment takes place should not be too tightly packed. Open space of about under 10% to over 65% of the volume capacity is sufficient to allow penetration of steam to all chip surfaces provided that the chips can be mechanically turned or agitated to prevent impeded exposure to steam at touching surfaces. For example, in the screw conveyor used in a preferred embodiment of the invention, the open space above the chips in the conveyor was found to be approximately 57% to 69%. In addition, the void space between the chips in the preferred embodiment amounted to approximately 61%. Therefore, the total void space in the conveyor amounted to approximately 83% (large chips) to 88% (small chips). Uniformity of steam treatment is very important, as the naturally occurring flora must be uniformly disabled or biosuppressed physiologically to avoid spots of overgrowth by contaminants during the subsequent incubation step.
A particularly efficient method of steam treatment is by injecting steam into a continuous flow screw or auger bearing the chips at about 30% to 45% spacial density as discussed above. It was found that exposure time of chips adequate for the present process could be only 40 seconds compared to 5–10 minutes in a quiescent batch mode. Steam was released at moderate pressure and applied ambiently without pressurizing the vessel.
A number of species of contaminating organisms can readily be isolated from moistened wood chips including Aspergillis spp., Colletotrichum spp., Trichoderma spp., Gliocladium spp., Ophiostoma spp., Penicillium spp., Ceratocystis spp., Nectria spp., Cytospora spp., and Alternaria spp. Many of these are more physiologically robust and faster growing than the inoculating lignin-degrading or modifying fungi of choice. Growth of these organisms is also enhanced in many instances by the nutrient adjuvants contained in the fungal inoculum. Therefore, addition of such nutrients is avoided.
Once the indigenous, undesirable microbes are disabled or suppressed by steam treatment, the less robust and more fastidious white-rot fungi in the inoculum are able to remain dominant over extended periods. The disabled organisms are still viable and capable of becoming dominant, as shown by biopulping runs in which the treatment temperature was inadvertently allowed to rise only to sub-optimal levels. In those instances the runs were ruined by overgrowth of the contaminating fungi. Clearly a highly delicate but controllable process balance must be maintained, but it is unclear scientifically what competitive factors are at work to maintain the desired biological balance over extended incubations. Reducing exposure to steam to a minimum without sterilization also has favorable implications for process costs. The low exposure time conductive to a continuous treatment means that high volume treatment required in any commercial scale process is attainable in the present invention.
If steam or heat is used to sterilize the wood chips, the chips are preferably cooled prior to inoculation of the biopulping fungi to minimize the possiblity of killing or disabling the organisms in the inoculum. Chips steam treated on a continuously moving path are passed through heat transfer means which cool the chips to an appropriate temperature for inoculation. Applicants have found that the most cost effective and simplest method is to place an in-line air blower manifold directly in the conveyance path, and adjust the air flow to a rate that will cool the passing chips adequately.
Chips to be inoculated with Ceriporiopsis subvermispora L14807 SS-3 are preferably cooled to no more than about 50° C., more preferably to a temperature between about 40° C. and about 45° C. The highest temperature tolerated by biopulping organisms will vary from species to species or even from strain to strain of the same species, so that empirical tests may be necessary to determine a physiologically suitable temperature for inoculation of wood chips with any given type of culture. Cooling only to the highest physiologically suitable temperature minimizes the cooling time and speeds the process, and reduces the energy consumed.
Inoculation of the biopulping fungi is preferably carried out in-line, and applied as a liquid spray to the passing wood chips. As in the steam treatment, the working action of agitated conveyor or auger allows inoculum to be uniformly adsorbed onto the chip surfaces by tumbling and churning during rotary or other agitated conveyance. It is important that the inoculum be applied substantially thoroughly and uniformly to the chip surfaces. If the biopulping fungi are to maintain dominance over other flora, the contaminating flora should not be given a sufficient opportunity to reestablish themselves in local areas of the chip surfaces where coverage of inoculum is uneven.
The enzymatic breakdown or modification of lignin by fungi is an exothermic reaction, so that when a large mass of chips is undergoing delignification, a substantial concentration of heat ensues. As the surface area of the mass of chips diminishes relative to the total mass, the problem intensifies since wood itself is an excellent heat insulator. The most practical way to dissipate heat in the chips to prevent the temperature from exceeding the level at which the biopulping fungi are killed, and the contaminants begin to overgrow the fungi, is by forcing air through the chips.
It has been found that the temperature of chip piles can be adequately controlled and maintained at levels biocompatible with the continued propagation and dominance of the fungus by loading the chips onto an air pervious frame defining a plurality of ducts through which forced air is passed. It has been empirically determined that the humidity of the air should be in a range from at least 30% up to over 95% relative humidity, preferably about 85%, and the flow rate should be adjusted seasonally to maintain the temperature in the core of the pile within the active growth range of the fungus, which must be determined for each species. In the case of C. subvermispora , the range is approximately 27° to 32° C.
After inoculation, the chips may be conveniently collected in large piles. Temperature and humidity control are important for optimal fungal propagation and lignin degradation or modification. It has been determined that practical control can be maintained for piles loaded onto the bottom frame referred to above having dimensions about 40–55 feet high, 100 feet wide and any length. Two 400 foot long piles can accommodate a pulp plant utilizing 600 tons of chips daily. To obtain proper humidity, wet bulb/dry bulb tests can be performed on the influent air. Relative humidity should preferably be maintained at about 70%–90%. Humidification of air by conventional means such as fogging prior to pumping or fanning into the frame ducts is generally necessary. The amount of heat generated in the pile generally requires continuous dissipation by forced air flow even during the winter months in the northern climes.
Incubation times are related to the degree of lignin digestion or modification desired, the type of wood chips being handled, and the particular fungus or combination of fungi being utilized in the process. Useful periods of incubation range from a few days to four weeks. On the other hand, prolonged incubation results in larger standing inventories of chips and larger on site storage capacity.
Tubular reactors (silo reactors) can also be used for biopulping. This silo reactor has a large-scale (multiton) capacity. A perforated plate at the bottom of the reactor supports the chips approximately 5 cm above the bottom of the reactor. Air is supplied to this void space at the bottom center of the reactor. A baffle plate immediately above the air inlet distributes the air more evenly across the bottom of the reactor.
After the incubation of the fungi in the wood chips, the wood chips are then preferably subjected to a conventional mechanical refining process to make wood pulp of the desired level of freeness. Dilution water is added to the chips and the chips are run through a mechanical refiner through a number of passes. The number of passes of the chips/pulp mixture will depend upon the freeness desired for the particular paper application to be made. The chip/pulp mixture is fed through the refiner until the desired level of freeness is achieved. Thus freeness may be periodically monitored to determine the progress of the pulps toward the freeness level which is desired for the paper. Between passes the wood pulp may be dewatered as necessary.
The biomechanical pulps made through this procedure may then be made into paper using standard paper making techniques. It has been found that the standard techniques as described by the Technical Association of the Paper and Pulp Industry (TAPPI) which are known to work with mechanically refined pulps work equally well with the biomechanically refined pulps of the type created by the process described herein. Accordingly, the paper may be made in conventional methodologies. The paper from the biomechanically created pulp can be compared in quality, strength and texture to that created through simple mechanical pulping and it will be found that the biomechanically created pulp has significantly increased strength properties. Thus it is apparent that the process of the present invention does not sacrifice the quality or strength of the paper in order to achieve the highly desirable energy savings, but in fact results in a unique combination of both significant reduction in energy utilization in the process, and an increase in the strength properties of the resulting paper.
Biomechanical pulping of eucalyptus wood according to the process of the present invention produces paper of surprisingly high quality compared to previous studies with other woods. In previous studies, we have seen some improvements in paper strength properties during biomechanical pulping of both hardwood and softwood species with several white-rot fungi (U.S. Pat. No. 5,750,005 “Method of Enhancing Biopulping Efficacy,” Akhtar (1998)). For example, improvements were observed in burst index of up to 37% and tear index of up to 44% (see Table 1, below) with pine chips (softwood chips), and in tear index of up to 24% (see Table 2, below) with aspen chips (hardwood chips) processed by biomechanical pulping using various species of white-rot fungi compared to mechanical pulping without inoculation. Surprisingly, when eucalyptus wood chips were inoculated with Ceriporiopsis subvermispora , as described in the Examples below, substantial improvements in paper strength properties (burst index 70% and tear index 184%) were observed (see Table 3, below).
TABLE 1
Biomechanical pulping of pine (softwood) chips
with several white-rot fungi and strains
(2-week treatment).
% improvements
over control
Fungi/strain
Burst index
Tear index
Phlebia brevispora HHB-7099
0
13
Phlebia subserialis RLG 6074-sp
37
44
Dichomitus squalens MMB 10963-sp
13
41
Hyphodontia setulosa FP 106976
0
40
Perenniporia medulla-panis HHB 12172
24
34
Ceriporiopsis subvermispora CZ-3
0
14
Ceriporiopsis subvermispora FP-105752 SS-4
0
14
Ceriporiopsis subvermispora L-14807 SS-1
0
14
Ceriporiopsis subvermispora L-14807 SS-3
0
21
Ceriporiopsis subvermispora L-14807 SS-5
0
21
Ceriporiopsis subvermispora L-14807 SS-10
0
11
TABLE 2
Biomechanical pulping of aspen (hardwood) chips
with several white-rot fungi and strains
(2-week treatment).
% improvement
over control
Fungi/strain
Burst index
Tear index
Phlebia subserialis RLG 6074-sp
0
0
Hyphodontia setulosa FP 106976
0
0
Phlebia brevispora HHB 7099
0
19
Phlebia tremelosa FP 102557-sp
0
24
Ceriporiopsis subvermispora L-14807 SS-3
0
11
TABLE 3
Biomechanical pulping of Eucalyptus grandis (hardwood)
chips with Ceriporiopsis subvermispora L-14807 SS-3
(2-week treatment).
% improvement over control
Burst index
Tear index
70
184
Previous data with both hardwood and softwood species, including the data summarized in Tables 1 and 2, above, show strength improvements with fungus-treated chips compared to the control. However, these improvements are not as pronounced as those obtained during biomechanical pulping of eucalyptus wood chips, shown in Table 3 and in the Examples below. Eucalyptus is a hardwood species with poor paper strength, due to short fiber length. Because of its poor paper strength properties, this wood has traditionally been considered to be of only limited use in the production of pulp utilized in mechanical pulping processes. Therefore, traditionally, in the final furnish from which newsprint and tissue paper is produced, a significant amount of kraft pulp (about 50%) is mixed with eucalyptus mechanical pulp to impart strength. Biomechanical pulping of eucalyptus wood according to the process of the present invention results in such a substantial increase in fiber strength that it is possible to significantly reduce the amount of kraft pulp required for a final furnish.
Biomechanical eucalyptus pulp behave more like a softwood mechanical pulp, with the strength characteristics of such a pulp, than it behaves like a traditional hardwood pulp. These highly unexpected results have only been observed with only eucalyptus wood. We have evaluated other types of hardwood in the past, but never achieved such improvements in paper strength properties.
Details of the process of the present invention will become more apparent from the following examples which illustrate laboratory-scale embodiments on of the process of the present invention, and results achieved thereby.
EXAMPLES
Example 1
Biomechanical Pulping of Eucalyptus Wood
Eucalyptus wood chips were supplied by a mechanical pulp mill in Brazil. Chips were placed in plastic bags and frozen to prevent the growth of contaminating microorganisms.
Bioreactors containing 1.5 kg of chips (dry weight basis) were steam sterilized for 10 min. prior to inoculation. After cooling at room temperature, these chips were inoculated with a suspension containing, water, unsterilized corn steep liquor and fungus. The inoculated bioreactors were incubated for 2 weeks at 27° C. and 65% relative humidity. The control and fungus-treated wood chips were refined to a pulp and then used to produce paper. The chips were heat treated with steam pressurized to 15 p.s.i.g. for 1 minute and 15 seconds. During this time, the chips were sent through a thermo-mechanical refiner (Sprout-Bauer, model # 1210P, having a plate pattern D2B505, and 300-mm diameter) for fiberization. The pulp produced was subsequently fiberized in a Sprout-Waldron Model D2202 single rotating 300 mm diameter disk atmospheric refiner. Pulp was collected at each pass as hot water slurry. Between the passes the pulp slurry was dewatered to approximately 25% solids in a porous bag by vacuum. Dilution water at 85° C. was then added each time as the pulp was fed into the refiner. Samples of the pulp were taken and tested for the Canadian Standard Freeness (CSF) and the process continued until the samples were refined to 300–500 CSF. Hand sheets were also prepared and tested using TAPPI standard testing methods.
Fungal pretreatment of eucalyptus wood chips was found to enhance paper strength properties substantially compared to the untreated control (see Table 4, below). The fungal pretreatment increased burst index by 70%, tear index by 184%, tensile strength by 120% and breaking length by 120% compared to the control.
TABLE 4
Paper strength properties comparison.
Strength properties
Control (untreated) chips
Fungus-treated chips
Freeness (ml)
402
390
Burst index (kN/g)
0.20
0.34
Tear index (mNm2/g)
1.03
2.93
Tensile strength (Nm/g)
5.16
11.35
Breaking length (m)
526
1157
The results summarized above indicated that the treated mechanically processed fibers were stronger than conventional mechanical fibers.
Example 2
Replacement of 30% Kraft Pulp in a 50/50 Mechanica/Kraft Pulp
Most paper is generally produced from a furnish which is a combination of mechanical and chemical pulp, such as kraft pulp. Kraft pulp fibers are generally included in most papers because of their high strength and low lignin content. Unfortunately, kraft pulp fibers are expensive to produce. Kraft pulp is mixed with mechanical pulp to cut down on costs of production. However, there is generally a limit to what proportion of a pulp can comprise mechanical pulp fibers, without compromising the quality of the paper produced therefrom.
In this Example, paper produced from untreated pulp samples consisting of 50% mechanical fibers plus 50% hardwood bleached kraft pulp fibers was compared to paper produced from fungus-treated pulp samples consisting of 80% biomechanical fibers plus 20% hardwood bleached kraft pulp fibers. The results of this study are summarized in Table 5, below. These results clearly indicate that at least 30% of the expensive kraft fibers in a 50/50 mix of mechanical/kraft pulp can be substituted with biomechanical pulp fibers, which are significantly less expensive than kraft pulp. The hardwood bleached kraft pulp fibers were 100% hardwood, commercial grade, and were produced by a paper mill in Brazil.
TABLE 5
Kraft substitution studies with pulp samples.
Fungus-treated
Strength properties
Control (untreated) chips a
chips b
Burst index (kN/g)
0.35
0.38
Tear index (mNm 2 /g)
1.69
2.92
Tensile strength (Nm/g)
9.40
11.26
Breaking length (m)
959
1148
Density (kg/m 3 )
310
307
Specific volume (cm 3 /g)
3.23
3.26
Drainage time (second)
5
5
a 50% TMP + 50% hardwood bleached kraft pulp.
b 80% Bio-TMP + 20% hardwood bleached kraft pulp.
Example 3
Replacement of 40% Kraft Pulp in a 50/50 Mechanica/Kraft Pulp
Eucalyptus wood was pulped in separate portions as described in Examples 1–2, using mechanical or biomechanical pulping techniques. Paper was produced from a furnish of an untreated pulp of 50% mechanical pulp, 40% hardwood bleached kraft pulp, and 10% softwood kraft pulp was prepared as a control, above. Paper was also produced from a furnish of treated pulp of 90% biomechanical ecucalyptus fibers and 10% softwood fungus-treated kraft pulp, and compared to paper produced from the control pulp. The results of this study are presented in Table 6, below.
TABLE 6
Kraft substitution studies with pulp samples.
Fungus-treated
Strength properties
Control (untreated) chips a
chips b
Burst index (kN/g)
0.35
0.68
Tear index (mNm 2 /g)
2.50
3.83
Tensile strength (Nm/g)
9.41
14.50
Breaking length (m)
960
1476
Specific volume (cm 3 /g)
3.02
3.17
a 50% TMP + 40% hardwood bleached kraft + 10% softwood kraft pulp.
b 90% Bio-TMP + 0% hardwood bleached kraft + 10% softwood kraft pulp.
The results of this study suggest the possibility of replacing even 40% hardwood bleached kraft pulp with biomechanical fibers in a blend containing 50% kraft pulp fibers.
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In a new process for preparing pulped wood chips for paper making, chips from a hardwood such as eucalyptus are inoculated with aliving culture of one or more white rot fungi. The fungi propagate throughout the body of the wood chip, selectively attacking the lignin of the wood without harming the cellulosic fibers. Subsequent mechanical pulpting results in reduced utilization of energy, improved strength, and reduced cooking time.
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The benefit of U.S. Provisional Patent Application Ser. No. 61/353,503, filed on Jun. 10, 2010, is claimed hereby. The teachings of U.S. Provisional Patent Application Ser. No. 61/353,503 are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
This invention relates generally to flexible hoses and, more particularly, to flexible hoses having a hose construction that is kink, crush, and burst resistant.
BACKGROUND OF THE INVENTION
Flexible hoses are widely utilized in countless applications. For instance, garden hoses are used for watering grass, trees, shrubs, flowers, vegetable plants, vines, and other types of vegetation. Garden hoses are also commonly used to supply water for cleaning houses, buildings, boats, equipment, vehicles, animals, and the like. Fluids, such as beverages, fuels, liquid chemicals, gases and air are also frequently delivered from one location to another through a flexible hose.
Flexible hoses have been manufactured for decades out of natural rubber, synthetic rubbers, thermoplastic elastomers, and plasticized thermoplastic materials. Conventional flexible hoses commonly have a layered construction that includes an inner tubular conduit, a spiraled, braided, or knitted reinforcement wrapped about the tubular conduit, and an outer cover.
Kinking is a problem that has been associated with flexible hoses since their commercialization and continues to be a problem today. Kinking is a phenomenon that may occur when the hose is doubled over or twisted. A consequence of kinking is that the flow of fluid through the hose can be either severely restricted or blocked. Kinking is a nuisance that causes the user to waste time unkinking the hose. Extreme kinking may occur when, for example, a newly purchased coiled garden hose is initially used. At the time of initial use, a coupling at one end of the hose is fastened to a faucet. The user typically grasps the opposite end of the hose and move away from the faucet without allowing the coiled hose to untwist. Kinking also occurs after the initial use as a consequence of routine movements by the user. Virtually everyone that has used in garden hose in cleaning or gardening has at one time or another been aggravated by a kinked hose.
When a hose kinks, the flow of fluid through the hose is blocked. The user must then attempt to remove the blockage by manual manipulation, such as by swinging the hose to relax the kink or approaching the kinked location and manually straightening the kink. A kink in a garden hose may require the user to return to the faucet, shut off the flow of water at the faucet to release the fluid pressure in the hose, and then manually unkink the hose. The user suffers further inconvenience because he or she must walk back, reestablish the flow of water through the hose, and then return to the opposite end of the hose to continue use. An even more acute problem arises when the user has already attached a large sprinkler device, such as an oscillating sprinkler to the end of the hose, and is forced to untwist the hose with the sprinkler attached.
The tendency of flexible hoses to kink may be at least partially alleviated by winding a helical wrap about the exterior of the inner tubular conduit. However, because of the choice of construction materials for the wrap and conduit, such kink resistant hoses achieve enhanced flexibility by sacrificing crush resistance to an externally applied force. When these reinforced hoses are deformed, for example by walking on or driving over them with a car, the helical wrap tends to permanently deform. The permanent deformation that results from being crushed restricts path for fluid to flow through the hose. Another approach for increasing the kink resistance of flexible hoses is to increase the wall thickness of the tubular conduit. However, increasing the wall thickness sacrifices hose flexibility such that these hoses are more cumbersome for a user to handle and manipulate. Increasing the wall thickness also makes the hose heavier and accordingly more difficult to move and use.
U.S. Pat. No. 7,658,208 discloses a flexible hose that is depicted as having kink, crush, and burst resistance. The flexible hose described in U.S. Pat. No. 7,658,208 is comprised of: a tubular member comprising a sidewall aligned along a longitudinal axis and a lumen radially inside said sidewall, said tubular member comprising an ethylene-octene interpolymer comprising polymerized units of ethylene and 1-octene, wherein the interpolymer is characterized by an average block index greater than zero and up to about 1.0 and a molecular weight distribution, M w /M n , greater than about 1.3 and a helical reinforcement strip at least partially embedded within said sidewall of said tubular member and helically wound with a pitch about said lumen of said tubular member, said reinforcement strip comprising a blend of polypropylene and an ethylene-butene interpolymer of ethylene and 1-butene, where the ethylene-butene interpolymer is characterized by an average block index greater than zero and up to about 1.0 and a molecular weight distribution, Mw/Mn, greater than about 1.3.
United States Patent Application Publication No. 2010/0071795 A1 also describes flexible hoses having a kink, crush, and burst resistant construction. A hose revealed by United States Patent Application Publication No. 2010/0071795 A1 is comprised of an inner tubular member; an outer tubular member; a yarn layer disposed between the inner and outer tubular members; and a plurality of reinforcement strips within the outer tubular member and helically wound with a pitch about the lumen of the tubular member, wherein the outer tubular member is composed of a first compound containing an olefin block copolymer and a styrene/ethylene-butylene/styrene-based thermoplastic elastomer, and the reinforcement strips are composed of a second compound containing a thermoplastic elastomer and a polypropylene homopolymer.
SUMMARY OF THE INVENTION
The flexible hose of the present invention is crush resistant, burst resistant, and virtually impossible to kink in normal use. The hose construction of the present invention is applicable to hoses that are designed for delivering virtually any kind of fluid including water, organic liquids, aqueous based herbicides, aqueous based insecticides, industrial chemicals, beverages, air, industrial gases, vacuum and the like. The hose design of the present invention is particularly applicable to garden hoses for the delivery of water. In fact, garden hoses having the construction of the present invention are highly resistant of kinking and almost never kink when being used in conventional lawn, garden, and cleaning applications.
This invention is based upon the unexpected finding that the kink resistance of hoses can be greatly improved by incorporating a fabric reinforcing layer having a special construction therein. This special construction allows for an increase in ratio of bend stiffness to torsional stiffness which causes the hose to have a propensity to twist rather than kink. For the first time, the flexible hoses of this construction take advantage of this methodology to resist kink formation. This fabric reinforcing layer is located between the inner tubular layer and the outer tubular layer of the hose. The construction employed in the fabric reinforcing layer includes a first plurality of reinforcing cords which extend spirally through the hose and are substantially parallel to each other and a second plurality of reinforcing cords which extend spirally through the hose and are substantially parallel to each other. In this construction, the first plurality of reinforcing cords are oriented at an angle α which is within the range of 20° to 50° of the longitudinal axis of the hose, and wherein the second plurality of reinforcing cords are oriented at an angle β which is within the range of 60° to 85° of the longitudinal axis of the hose, wherein the angle α and the angle β are mutually opposite with respect to the longitudinal axis of the hose. In addition to the special fabric reinforcing layer, the hoses of this invention also utilize one or more reinforcing strips which are at least partially embedded within the outer tubular layer. These reinforcing strips are helically wound in the direction of angle β with respect to the orientation of the reinforcing cords.
The present invention more specifically discloses a kink, crush, and burst resistant hose having a longitudinal axis and a lumen for conveyance of a fluid comprising (1) an inner tubular layer, (2) a fabric reinforcing layer wherein said fabric reinforcing layer is comprised of a first plurality of reinforcing cords which extend spirally through the hose and are substantially parallel to each other and a second plurality of reinforcing cords which extend spirally through the hose and are substantially parallel to each other, wherein the first plurality of reinforcing cords are oriented at an angle α which is within the range of 20° to 50° of the longitudinal axis of the hose, and wherein the second plurality of reinforcing cords are oriented at an angle β which is within the range of 60° to 85° of the longitudinal axis of the hose, wherein the angle α and the angle β are mutually opposite with respect to the longitudinal axis of the hose (3) an outer tubular layer, and (4) at least one reinforcing strip which is at least partially embedded within the outer tubular layer and helically wound in the direction of β with respect to the orientation of the reinforcing cords and a pitch about the lumen of said hose.
In the hose construction of the present invention the cords in the first plurality of reinforcing cords and the cords in the second plurality of reinforcing cords are spirally wound to form the fabric reinforcing layer. In this construction the cords in the fabric reinforcing layer are in the form of a non-woven matrix wherein all of the cords wound at angle α either pass over or pass under all of the cords wound at angle β. The kink, crush, and burst resistant hose of the subject invention typically has a ratio of bend stiffness to torsional stiffness which is greater than 1.0, preferably greater than 1.2, and most preferably greater than 1.3.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings which are incorporated herein constitute a part of this specification and illustrate various embodiments of the subject invention. These drawings are intended to be used in conjunction with the written description to provide clear understanding of the nature and scope of the subject invention. It should be understood that in referencing the figures submitted herein and in understanding the hoses of this invention that mirror images of such hoses are within the nature and scope of the invention. It should accordingly be understood that the angle α and the angle β depicted and described herein can be interchanged to depict the minor image of the drawings and descriptions provided herein.
FIG. 1 is a perspective view of a garden hose construction in accordance with one embodiment of the subject invention.
FIG. 2 is a perspective view of a portion of the hose of FIG. 1 in which the layers are partially removed for purposed of better illustration of the hose construction of this invention.
FIG. 2A is a side view of a portion of the hose of FIG. 1 in which the layers are partially removed for purposed of better illustration of the hose construction of this invention.
FIG. 3 is a cross-sectional view taken along a vertical section of FIG. 2 showing the inner tubular layer, the fabric reinforcing layer having the special construction of this invention, the outer tubular layer, and helically wound reinforcing strips which are fully embedded within the outer tubular layer.
FIG. 4 is a view illustrating the orientation of the cords in the fabric reinforcing layer in relation to the longitudinal axis of the hose. FIG. 4 illustrates a hose wherein the helically wound reinforcing strips are partially embedded within the outer tubular layer.
FIG. 5 is an illustration depicting the measurement of Bending stiffness (EI).
FIG. 6 is an illustration depicting the measurement of Torsional stiffness (GJ).
FIG. 7 is an illustration depicting a kink resistant flexible hose in accordance with one embodiment of this invention wherein the fabric reinforcing layer includes a first longitudinal reinforcing cord and a second longitudinal reinforcing cord.
DETAILED DESCRIPTION OF THE INVENTION
The flexible hose of this invention has a longitudinal axis 30 that is diametrically centered within the lumen 28 of the hose 10 . The hose 10 extends axially for an indefinite length along the central longitudinal axis 30 and has a length that may vary depending upon the intended use. In some cases the hose may be relatively short. However, the benefit attained by utilizing the highly kink resistant design of this invention is of the greatest value in longer hoses which are more susceptible to kinking. In many cases the flexible hoses of this invention will be 10 feet (3 meters) to 300 feet (91 meters) long. The flexible hoses of this invention will commonly be 20 feet (6 meters) to 200 feet (61 meters) long. For instance, garden hoses having the construction of this invention will typically be 25 feet (8 meters) to 100 feet (30 meters) long. The flexible hoses of this invention typically have an inside diameter which ranges from about 0.125 inch (0.3 cm) to about 2 inches (5 cm) or even larger. The inside diameter of the flexible hoses of this invention is commonly within the range of 0.25 inch (0.6 cm) to 1 inch (2.5 cm) and is frequently within the range of 0.5 inch (1.3 cm) to 0.75 inch (1.9 cm).
Hose 10 may be adapted for use in a wide variety of industrial or household applications. One commercial application for hose 10 is a garden or water hose for household or industrial use. Another commercial application for hose 10 is a drop hose mainly used for the transfer of various fluids including, but not limited to, gasoline, petroleum-based products, chemicals, petrochemicals, and fluid food products. Hose 10 may be also used to make pneumatic hoses for use in conjunction with pneumatic tools and other fluid actuated devices. The flexible hoses of this invention are also useful in conjunction with central vacuum cleaner systems for homes and other buildings.
Opposite ends 32 , 34 of the flexible hose 10 are typically terminated by conventional hose fittings 36 , 38 , respectively, used for coupling the flexible hose 10 to complementary hose fittings (not shown) of a fluid source, a water faucet, a fluid drain, a fluid dispenser, or even another flexible or rigid hose or conduit. However, in one embodiment of this invention the flexible hose is not terminated with a coupling on one or both of the ends thereof.
The flexible hose of this invention is of the general construction as illustrated and described in United States Patent Application Publication No. 2010/0071795 A1 and can typically be manufactured using the materials described therein. However, in making the hoses of this invention the fabric reinforcing layer described herein is substituted for the yarn layer described in United States Patent Application Publication No. 2010/0071795 A1. It should be understood that specific hose constructions and materials that go beyond the embodiment disclosed in United States Patent Application Publication No. 2010/0071795 A1 can be employed in the flexible hoses of this invention. In any case, the teachings of United States Patent Application Publication No. 2010/0071795 A are incorporated herein for the purpose of teaching a hose construction and materials that can be utilized in manufacturing the kink resistant hoses of this invention.
The flexible hoses of the present invention include (1) an inner tubular layer, (2) a fabric reinforcing layer having the special construction of this invention, (3) an outer tubular layer, and (4) at least one helically wound reinforcing strip which is at least partially embedded within the outer tubular layer. The hose 10 may be manufactured or fabricated using extrusion techniques known to a person having ordinary skill in the art. In one embodiment, the inner tubular layer (inner tubular member) 24 is formed as an extrusion and the fabric layer 22 is applied to the exterior of the inner tubular layer 24 by winding the reinforcing cords onto the inner tubular layer. A portion of the outer cover 12 is then applied over the fabric reinforcing layer, and the reinforcement strips 14 , 16 , 18 , 20 are applied in a die spinning process, and then the remainder of the outer cover 12 is applied.
The inner tubular layer 24 is formed from a low modulus rubber or thermoplastic elastomer or similar material that is chemically resistant, chemically inert, and resistant to permeation by the fluid conveyed through the lumen 28 . The inner tubular layer 24 lends strength to the hose 10 for increasing the burst pressure and operates in this regard with the yarn layer 22 and reinforcement strips 14 , 16 , 18 , 20 to provide a relative high burst pressure. The inner tubular member 24 is relatively flexible with a low initial modulus so that the hose 10 is not overly stiff or rigid.
The formulation for the material forming the inner tubular layer 24 may comprise a compound of a polypropylene homopolymer and an olefin block copolymer. In particular, the polypropylene homopolymer may be H110-02N polypropylene and the olefin block copolymer may be Infuse D9107 blended in a ratio of about 90 weight percent olefin block copolymer to about 10 weight percent polypropylene homopolymer. The low modulus material from which the inner tubular member 24 is formed may include from 0.5 weight percent to 2.0 weight percent of pigments and/or dyes to provide a color and additives, such as ultraviolet stabilizers, heat stabilizers, antioxidants, antiozonants, lubricants, and the like.
The material employed in making the inner tubular layer and the low modulus portion of the outer tubular layer can also be natural rubber, a synthetic rubber, a thermoplastic elastomer, or a plasticized thermoplastic material, such as polyvinyl chloride (PVC). It should be appreciated that the inner tubular layer and the low modulus portion of the outer tubular layer can be made from the same or different materials or combination of materials. Natural rubber, styrene-butadiene rubber, synthetic polyisoprene rubber, polybutadiene rubber, nitrile rubber, and various blends thereof can be formulated to offer excellent physical and chemical characteristics, such as excellent durability, low temperature flexibility, and chemical resistance. However, it is typically necessary to cure such natural and synthetic rubber containing formulations with sulfur or a sulfur-containing curing agent and to include one or more antidegradants in the formulation thereof. Thermoplastic elastomers and thermoplastic resins offer the advantage of not needing to be cured. However, a plasticizer is needed in formulations made with thermoplastic resins, such as PVC to attain needed levels of flexibility.
In one embodiment of this invention, the low modulus material constituting the inner tubular layer 24 exhibits an initial modulus in a range between about 200 psi (1.4 MPa) and about 5,000 psi (34.5 MPa). The initial modulus of the low modulus material is frequently in the range of 3,500 psi (24.1 MPa) about 4500 psi (31.2 MPa). The minimum tensile strength for the low modulus material may be as low as about about 800 psi (5.5 MPa) and is preferably at least 900 psi (6.2 MPa).
The fabric reinforcing layer is located between the inner tubular layer and the outer tubular layer. It is typically applied to the inner tubular layer in manufacturing the hose of this invention by winding strands of reinforcing cord onto the inner tubular layer. In doing so, one or more cords are wound at an angle α which is within the range of 20° to 50° of the longitudinal axis of the hose to form the first plurality of cords in the reinforcing layer. Then, one or more cords are wound at an angle β which is within the range of 60° to 85° of the longitudinal axis of the hose to form the second plurality of cords in the reinforcing layer. It should be noted that the angle α and the angle β are mutually opposite with respect to the longitudinal axis of the hose as is illustrated in FIG. 4 . The cords in the first plurality of cords in the fabric reinforcing layer are typically wound at an angle α which is within the range of 25° to 35° of the longitudinal axis of the hose with the cords in the second plurality of cords being wound at an angle β which is within the range of 75° to 85° of the longitudinal axis of the hose. The cords in the first plurality of cords 56 in the fabric reinforcing layer are more typically wound at an angle α which is within the range of 27° to 33° of the longitudinal axis of the hose with the cords in the second plurality of cords 57 being wound at an angle β which is within the range of 77° to 83° of the longitudinal axis of the hose. It is also important as shown in FIG. 4 for the reinforcing strips 14 and 16 to be helically wound in the direction of β wherein β is an angle less than 90°. It should be noted that for purposes of this invention, angle α and angle β are always less than 90°. The cords in the first plurality of cords in the hose will also preferably be somewhat slack (not fully taut). It has been found better torsional flexibility of the hose of this invention is maintained in cases where the first plurality of cords in the hose are slightly slack. In most cases, the first plurality of cords will be slack to a degree in which they can experience a strain within the range of 0.25% to 5%, typically within the range of 0.5% to 4%, and more typically will be within the range of 1% to 2% without exhibiting an increase in the level of stress.
The second plurality of cords is simply wound over the first plurality of cords to produce a spirally wound fabric reinforcing layer. It is accordingly a nonwoven fabric rather than being a knitted-type reinforcement or a mesh network. More specifically, in the hose construction of the present invention, the cords in the first plurality of reinforcing cords and the cords in the second plurality of reinforcing cords are spirally wound to form the fabric reinforcing layer. In this construction, the cords in the fabric reinforcing layer are in the form of a non-woven matrix wherein all of the cords wound at angle α either pass over or pass under all of the cords wound at angle β. The kink, crush, and burst resistant hose of the subject invention typically has a ratio of bend stiffness to torsional stiffness which is greater than 1.0, preferably greater than 1.2, and most preferably greater than 1.3.
The kink resistant flexible hose of this invention will preferably further include longitudinal cords in the fabric reinforcing layer. The number of the longitudinal cords included in the fabric reinforcing layer will typically range from 1 to about 20, will more typically be within the range of 1 to about 10 and will preferably be a number within the range of 1 to 5. The number of longitudinal cords included in the fabric reinforcing layer will typically be 1, 2, 3, or 4. FIG. 7 illustrates a kink resistant flexible hose in accordance with one embodiment of this invention wherein the fabric reinforcing layer includes a first longitudinal reinforcing cord 50 and a second longitudinal reinforcing cord 51 . The angular spacing θ between the longitudinal cords utilized in reinforcing the hose will typically be within the range of 2 degrees to 90 degrees, will more typically be within the range of 4 degrees to 45 degrees, and will preferably be within the range of 5 degrees to 20 degrees. In cases where multiple longitudinal reinforcing cords are utilized in the hose all of the reinforcing cords will be present within this angular spacing θ which has a maximum separation of 90 degrees.
Bending stiffness (EI) is determined with reference to FIG. 5 according to the formula:
EI = PL 3 3 δ max
wherein E represents Young's Modulus, wherein I represents the Moment of Inertia of the beam or hose section, wherein P represents the load applied at end of beam or hose section, wherein L represents the Length of beam or hose section, and wherein δ max represents the Maximum deflection at end of beam or hose section.
Torsional stiffness (GJ) is determined with reference to FIG. 6 according to the formula:
GJ = TL θ
wherein G represemts Shear Modulus, wherein J represents the Polar Moment of Inertia, wherein L represents the Length of beam or hose section, wherein T represents the Applied torque at end of the beam or hose section, and wherein θ represents the angular deformation or twist in radians.
It should be noted that the term “cords” as used herein includes monofilaments, multi-filament materials, yarns comprising a plurality of filaments, or cords which are comprised of a plurality of filaments and/or yarns that are wound or structured in any construction. The cords can be made utilizing a wide variety of natural and/or synthetic materials, such as cotton, polyester (such as polyethylene terephthalate or polyethylene naphthalate), nylon, rayon, aramid, carbon fiber, ceramic fibers (such as silicon carbide), polyvinyl alcohol (PVA), poly p-phenylene-2,6-benzobisoxazole (PBO), polypropylene, and the like. In some applications, metallic cords or hybrid cords, such as steel cords which can optionally be plated with brass or another alloy can be utilized in the fabric reinforcing layer. For instance, reinforcement with steel cords can be beneficially utilized in high pressure hoses such as hydraulic hoses and high pressure steam hoses.
The outer cover 12 is composed of a flexible material characterized by a low initial modulus so that the hose 10 is not excessively stiff. In particular, the low modulus material constituting the outer cover 12 is significantly more flexible (i.e., has a lower initial modulus) than the high modulus material constituting the reinforcement strip 14 . In one aspect, the low modulus material constituting the outer cover 12 exhibits an initial modulus in a range from about 200 psi (1.4 MPa) to about 1,000 psi (6.9 MPa). In one embodiment, the initial modulus of the low modulus material is about 550 psi (3.8 MPa). The minimum tensile strength for the low modulus material may be about 800 psi (5.5 MPa), or greater. However, the minimum tensile strength may be as low as about 540 psi (3.7 MPa).
The formulation for the low modulus material constituting the outer cover 12 may be selected from the group consisting of olefin block copolymers (OBC), plasticized polyvinyl chlorides (PVC), plasticized polyvinyl chloride alloys, styrene/ethylene-butylene/styrene-based (SEBS) thermoplastic elastomers (TPE), thermoplastic vulcanizates (TPV), thermoplastic polyurethanes (TPU), polyolefin elastomers (POE), mixtures thereof, and the like. In an alternative embodiment of this invention, the low modulus material can be a thermoset material such as an ethylene propylene rubber (EPR) or an ethylene-propylene-diene rubber (EPDM). A particular olefin block copolymer for use in forming outer cover 12 is Infuse D9107 commercially available from The Dow Chemical Company (Midland, Mich.), which is characterized by a density of 0.866 grams per cubic centimeter (ASTM D792) and a melt mass flow rate of 1.0 grams per ten minutes (190° C./2.16 kg, ASTM D1238). In one embodiment, the low modulus material constituting the outer cover 12 may be composed of a 50:50 weight percent mixture of OBC and SEBS-based TPE. The low modulus material from which the outer cover 12 is formed may include from 0.5 wt. % to 2.0 wt. % of pigments to provide a color and additives like ultraviolet stabilizers, heat stabilizers, and lubricants. In one embodiment, the SEBS used in the low modulus material may be a compound containing 80 parts to 200 parts of oil and homopolymer, as well as fillers and additives.
The combination of a low modulus material for the outer cover 12 and a high modulus material for the reinforcement strips 14 , 16 , 18 , 20 is selected to construct a hose 10 that, in comparison with conventional hose constructions, exhibits acceptable flexibility, kink resistance, and crush resistance under zero- and low-fluid pressure conditions without sacrificing strength that resists bursting. In certain embodiments of the invention, the materials for the outer cover 12 and reinforcement strips 14 , 16 , 18 , 20 may be selected to operate under internal working fluid pressures ranging from about 15 psi (103 KPa) to about 500 psi (3.4 MPa).
Each of the reinforcement strips 14 , 16 , 18 , 20 includes a plurality of continuous coils or turns, that are wound with a spiral or helical winding pattern having a helical pitch measured along the central longitudinal axis 30 such that adjacent turns of the different strips 14 , 16 , 18 , 20 are non-contacting and, thereby, separated or spaced apart from each other by a center-to-center or centerline spacing, s. The pitches for the reinforcement strips 14 , 16 , 18 , 20 are approximately equal. The centerline spacing, s, between adjacent pairs of the reinforcement strips 14 , 16 , 18 , 20 may range from about 50 percent of the diameter, d, of the individual turns to about 500 percent of the diameter, d. In a specific embodiment, the centerline spacing, s, for adjacent pairs of the reinforcement strips 14 , 16 , 18 , 20 may be about 100 percent of the diameter, d. The turns of the reinforcement strips 14 , 16 , 18 , 20 may have a geometrical shape with a round cross section as depicted in FIGS. 2 and 3 , an oval cross section, a hexagonal cross section, or another suitable cross section. The axial gaps 46 between adjacent turns of the reinforcement strips 14 , 16 , 18 , 20 are filled by the material of the outer cover 12 . In an alternative embodiment, the hose 10 may include more or less than four reinforcements strips 14 , 16 , 18 , 20 so long as multiple strips are present.
The cross-sectional area of the reinforcement strips 14 , 16 , 18 , 20 , as well as the helical pitch of the reinforcement strips 14 , 16 , 18 , 20 , may influence the flexibility of the hose 10 and its strength against flattening and against pressure to resist bursting. Increasing the helical pitch of the reinforcement strips 14 , 16 , 18 , 20 in the axial direction increases the centerline spacing, s, which reduces the flexibility of the hose, and may decrease the strength against flattening and pressure resistance against bursting. Increasing the cross-sectional area of the reinforcement strips 14 , 16 , 18 , 20 increases the crush resistance against flattening but may reduce the flexibility.
In one aspect, the reinforcement strips 14 , 16 , 18 , 20 comprise a high modulus material having a greater initial modulus than a low modulus material forming the outer cover 12 . Because of the higher initial modulus, the high modulus material forming the reinforcement strips 14 , 16 , 18 , 20 have a greater rigidity (or lower flexibility) than the low modulus material forming the outer cover 12 . As understood by a person having ordinary skill in the art, the initial modulus is a physical property of a material measured from the slope of an engineering stress-strain curve at low strain levels near zero strain. An engineering stress-strain curve is a graph representing an experimental measurement derived from measuring load (i.e., stress) versus extension (i.e., strain) for a sample of a material. The shape and characteristics of the stress-strain curve vary with the type of material. The stress-strain curve features an initial elastic region over an initial range of relatively low applied stresses, followed by a plastic region over another range of moderate applied stresses, and ultimately fractures at a sufficiently high applied stress.
The high modulus material of reinforcement strips 14 , 16 , 18 , 20 may be composed primarily of a rigid thermoplastic elastomer (TPE), which is often referred to as a thermoplastic olefin (TPO). The high modulus material is selected imparts high burst strength, good crush resistance/resilience, and kink resistance to the hose 10 . In various embodiments, the high modulus material of reinforcement strips 14 , 16 , 18 , 20 may comprise a compound of a TPE and polypropylene having a composition ranging from about 80 percent by weight TPE to about 5 weight percent TPE. In other embodiments, the formulation for the high modulus material may range from about 20 weight percent TPE to about 5 weight percent TPE. Increasing the percentage by weight of polypropylene in the compound relative to percentage by weight of TPE is believed to increase the kink resistance of the hose 10 , but reduce the flexibility. The high modulus material from which the strips 14 , 16 , 18 , 20 are formed may include from 0.5 weight percent to 2.0 weight percent of pigments to provide a color and additives like ultraviolet stabilizers, heat stabilizers, and lubricants.
High modulus material formulations suitable for constructing the reinforcement strips 14 , 16 , 18 , 20 may comprise a compound of a polypropylene homopolymer and a TPE selected from the ENGAGE® family of ethylene-butene copolymers commercially available from The Dow Chemical Company (Midland, Mich.). In one embodiment, these materials are combined in a ratio of about 20 weight percent TPE to about 80 weight percent polypropylene homopolymer. A particularly useful polymer compound for the high modulus material of reinforcement strip 14 includes ENGAGE® ENR 7256 ethylene-butene copolymer and a polypropylene homopolymer, which may be combined in a ratio of about 20 weight percent TPE to about 80 weight percent polypropylene homopolymer. ENGAGE® ENR 7256 is characterized by a density of 0.885 grams per cubic centimeter (ASTM D792), a melt mass flow rate of 2.0 grams per ten minutes (190° C., ASTM D1238), and a tensile strength with a yield of 11.2 MPa when molded and tested in accordance with ASTM D638. A representative polypropylene homopolymer for use in the high modulus material of reinforcement strip 14 comprises H110-02N polypropylene that is commercially available from The Dow Chemical Company (Midland, Mich.). H110-02N polypropylene is characterized by a density of 0.900 grams per cubic centimeter (ASTM D792), a melt mass flow rate of 2.0 grams per 10 minutes (230° C.; ASTM D1238), and a tensile strength with a yield of 35.2 MPa when molded and tested in accordance with ASTM D638.
The high modulus material of reinforcement strips 14 , 16 , 18 , 20 may be selected with a composition that exhibits a minimum initial modulus of about 5,000 psi (34.5 MPa) and a minimum tensile strength of about 1,000 psi (6.8 MPa), or greater. The tensile strength represents the stress at the inflection point or maximum on the engineering stress-strain curve, which corresponds to the maximum stress that can be sustained by a structure in tension. In one embodiment, the high modulus material of reinforcement strip 14 is characterized by an initial modulus of about 40,000 psi (276 MPa) or greater and a tensile strength of about 1,600 psi (11 MPa) or greater. Although not wishing to be limited by theory, the relatively high initial modulus of the high modulus material of reinforcement strips 14 , 16 , 18 , 20 is believed to impart appreciable kink resistance to the hose 10 and the minimum tensile strength of the high modulus material of reinforcement strips 14 , 16 , 18 , 20 is believed to impart appreciable burst strength to the hose 10 .
The outer cover 12 operates to protect the inner tubular member 24 and the yarn layer 22 from the environment of the hose 10 when deployed for use in the field. The outer cover 12 also provides adhesion to the inner tubular member 24 that will not allow the yarn layer 22 to move around. The yarn layer 22 includes windows between the constituent filaments that permit the material of the outer cover 12 to contact the inner tubular member 24 and provide a cohesive hose construction.
References herein to terms such as “inner” or “interior” and “outer” or “exterior” refer, respectively, to directions toward and away from the center of the referenced element, and the terms “radial” and “axial” refer, respectively, to directions perpendicular and parallel to the longitudinal central axis of the referenced element are made by way of example, and not by way of limitation, to establish a frame of reference. It is understood that various other reference frames may be employed in describing the subject invention.
This invention is illustrated by the following examples that are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. Unless specifically indicated otherwise, parts and percentages are given by weight.
EXAMPLE 1 AND COMPARATIVE EXAMPLE 2
In this experiment, a hose was made utilizing the methodology of this invention and compared to an identical hose that was made utilizing a conventional fabric reinforcing layer. These hoses had an inside diameter of approximately 16 mm and outside diameters of approximately 23 mm. The inner tubular layer in the case of both hoses was made by extruding an SEBS compound having a wall thickness of approximately 1.3 mm. In the case of the experimental hose of this invention, the fabric reinforcing layer was made by winding eighteen separate polyethylene terephthalate polyester yarns at an angle α of 30° with respect to the longitudinal axis of the hose. Three separate polyethylene terephthalate polyester yarns were then wrapped on top of the first plurality of yarns at an angle β of 80° with respect to the longitudinal axis of the hose to make the fabric reinforcing layer which is comprised of a first plurality of eighteen yarns which are wrapped in the direction of α and a second plurality of three yarns which are wrapped in the direction of β. Then the outer tubular layer, including reinforcing strips embedded therein, were applied on top of the fabric reinforcing layer to make the hose. The outer tubular layer made with another SEBS compound and two reinforcing strips were made utilizing TPO. The reinforcing strips were about 2.5 mm in width by 2.5 mm in height and had a helical pitch of 12 mm.
In the case of the control hose, the fabric reinforcing layer was made by winding nine separate polyethylene terephthalate polyester yarns at an angle α of 54.7° with respect to the longitudinal axis of the hose. Nine separate polyethylene terephthalate polyester yarns were then wrapped on top of the first plurality of yarns at an angle β of 54.7° with respect to the longitudinal axis of the hose to make the fabric reinforcing layer which is comprised of a first plurality of nine yarns which are wrapped in the direction of α and a second plurality of nine yarns which are wrapped in the direction of β. Then the outer tubular layer, including reinforcing strips embedded therein, were applied on top of the fabric reinforcing layer to make the hose. The outer tubular layer made with another SEBS compound and two reinforcing strips were made utilizing TPO. The reinforcing strips were about 2.5 mm in width by 2.5 mm in height and had a helical pitch of 12 mm.
The conventional hose was determined to have a bending stiffness of 38.0 psi and a torsional stiffness of 145.4 psi which provides a stiffness ratio of 0.3. The experimental hose of this invention was determined to have a bending stiffness of 40.8 psi and a torsional stiffness of 29.2 psi which provides a stiffness ratio of 1.4.
The conventional hose was attached to a water spigot and was pressurized to approximately 60 psi which is standard commercial water pressure. The hose was pulled from a coil without allowing it to twist in the hand as a gardener or household user would handle it in normal applications. As the hose was pulled, numerous loops formed over the length of the hose eventually leading to several kinks which restricted the flow of water. In the case of the experimental hose which was similarly pressurized and handled, kinks did not form as was the case with the conventional hose. In fact, even after intentionally putting small loops in the hose and pulling, the natural inclination of the hose was to twist rather than kink. Intentional efforts to kink the experimental hose did not result in kink formation due to the fact that the experimental hose torsionally twisted out of loop.
While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention.
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The flexible hose of the present invention is crush resistant, burst resistant, and virtually impossible to kink in normal use and is applicable to hoses that are designed for delivering virtually any kind of fluid including water, organic liquids, aqueous based herbicides, aqueous based insecticides, industrial chemicals, beverages, air, industrial gases, vacuum, and the like. The hose design of the present invention is particularly applicable to garden hoses for the delivery of water. In fact, garden hoses having the construction of the present invention are highly resistant to kinking and almost never kink when being used in conventional lawn, garden, and cleaning applications.
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TECHNICAL FIELD
[0001] The present invention relates to a bis(tetrahydrofuran) compound, a process for producing the same, and a use of the compound.
BACKGROUND ART
[0002] Along with the arrival of an aging society, senile dementia such as Alzheimer's-type dementia, dementia with Lewy bodies, Parkinson's disease, etc. has become a serious social issue.
[0003] The onset mechanism of these types of dementia has yet to be fully determined. However, a remarkable degeneration of cholinergic neurons is found in patients with Alzheimer's-type dementia, and the degeneration and loss of midbrain dopaminergic neurons are found in patients with Parkinson's disease. Such degeneration and loss are believed to cause the onset of dementia.
[0004] Neurotrophic factors (NTF) is a generic term for substances that promote the survival, differentiation, and regeneration of nerve cells. Specifically, these substances are high molecular proteins such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), etc. NGF acts on cholinergic neurons, and BDNF acts on both cholinergic neurons and midbrain dopaminergic neurons. If the activities of these neurotrophic factors are successfully enhanced, such enhancement is likely to produce effective prevention or treatment of the above-described dementia.
[0005] Patent Document 1 discloses the use of one of the components of Compositae plants, i.e., helioxanthin, as an agent to enhance the activity of a cell differentiation inducing factor.
[0006] However, an effective preventive or treatment agent for patients with senile dementia, whose number is expected to increase, has not yet been developed.
[0007] Patent Document 1: Japanese Unexamined Patent Publication No. H9-151132
DISCLOSURE OF THE INVENTION
Technical Problem
[0008] An object of the present invention is to provide a new bis(tetrahydrofuran) compound having an excellent neurotrophic factor activity-enhancing effect, and a process for producing the bis(tetrahydrofuran) compound.
Technical Solution
[0009] The present inventors conducted intensive studies in an attempt to solve the above-described problem, and found that a bis(tetrahydrofuran) compound synthesized for the first time by the present inventors has an excellent neurotrophic factor activity-enhancing effect. The present invention has been completed based on such finding.
[0010] As shown in the following items 1 to 10, the present invention provides a bis(tetrahydrofuran) compound, a process for producing the same, and a neurotrophic factor activity enhancer containing the compound or a composition for ameliorating neurological disease containing the compound. Item 1. A bis(tetrahydrofuran) compound represented by formula (1):
[0000]
[0000] wherein R 1 and R 2 are the same or different, and represent a C 1-4 alkyl group, a C 1-5 alkoxy group, an aryl C 1-5 alkoxy group, a C 2-5 alkenyloxy group, or an aryl C 2-5 alkenyloxy group, or R 1 and R 2 together represent ═O or ═CH 2 ; R 3 represents a hydrogen atom or a group —CH 2 —O—R 4 ; R 4 represents a C 1-4 alkyl group, a C 1-5 alkylcarbonyl group, or an aryl C 1-4 alkyl group optionally having one or more substituents on the aryl ring; and a carbon-carbon bond between “a” and “b” represents a single bond or a double bond.
Item 2. The bis(tetrahydrofuran) compound according to Item 1, wherein R 1 and R 2 together represent ═O in formula (1).
Item 3. The bis(tetrahydrofuran) compound according to Item 1, wherein R 1 and R 2 together represent ═CH 2 in formula (1).
Item 4. The bis(tetrahydrofuran) compound according to Item 1, wherein R 1 represents a C 1-4 alkyl group, and R 2 represents a C 1-5 alkoxy group, an aryl C 1-5 alkoxy group, a C 2-5 alkenyloxy group, or an aryl C 2-5 alkenyloxy group.
Item 5. A process for producing the bis(tetrahydrofuran) compound of Item 2, comprising reacting an acrylic acid compound represented by the following formula (2) with a quaternary ammonium fluoride:
[0000]
[0000] wherein R 3 and a carbon-carbon bond between “a” and “b” are as defined above; R 5 represents a C 1-4 alkyl group; and R 6 represents a silyl-based protecting group.
Item 6. A process for producing the bis(tetrahydrofuran) compound of Item 3, comprising reacting the bis(tetrahydrofuran) compound of Item 2 with Tebbe's reagent.
Item 7. A process for producing the bis(tetrahydrofuran) compound of Item 4, comprising reacting the bis(tetrahydrofuran) compound of Item 3 in an alcohol in the presence of an acid catalyst.
Item 8. A neurotrophic factor activity enhancer containing the bis(tetrahydrofuran) compound of Item 1.
Item 9. The activity enhancer according to Item 8, wherein the neurotrophic factor is a nerve growth factor or a brain-derived neurotrophic factor.
Item 10. A composition for ameliorating neurological disease, the composition containing the bis(tetrahydrofuran) compound of Item 1.
ADVANTAGEOUS EFFECTS OF THE INVENTION
[0011] Bis(tetrahydrofuran) compounds represented by formula (1) of the present invention have an excellent neurotrophic factor activity-enhancing effect, and thus can be suitably used for the prevention or treatment of neurodegenerative diseases such as senile dementia commonly known as Alzheimer's disease, Down syndrome, Parkinson's disease, Creutzfeldt-Jakob disease, amyotrophic lateral sclerosis (ALS), and diabetic neuropathy; diseases caused by neurological disorders such as mental disorders including depression and schizophrenia; neurological disorders caused by sequelae of encephalitis, cerebral palsy, and head and/or spinal cord injuries; and cerebral vascular disorders associated with cerebral infarction, intracerebral bleeding, and cerebral arteriosclerosis. Among the bis(tetrahydrofuran) compounds represented by formula (1), bis(tetrahydrofuran) compounds represented by formulae (1C) and (1D) are particularly excellent in exhibiting the above effects.
[0012] The production process of the present invention can provide a new bis(tetrahydrofuran) compound as described above that has an excellent neurotrophic factor activity-enhancing effect.
[0013] Bis(tetrahydrofuran) compounds represented by formulae (1A) and (1B) of the present invention are useful intermediates for producing the bis(tetrahydrofuran) compounds represented by formulae (1C) and (1D).
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a micrograph showing cells cultivated in a medium containing DMSO.
[0015] FIG. 2 is a micrograph showing cells cultivated in a medium containing DMSO and NGF (20 ng/ml).
[0016] FIG. 3 is a micrograph showing cells cultivated in a medium containing DMSO, NGF (20 ng/ml), and bis(tetrahydrofuran) compound (1C-2-1) (1 μM) of the present invention.
[0017] FIG. 4 is a micrograph showing cells cultivated in a medium containing DMSO, NGF (20 ng/ml), and bis(tetrahydrofuran) compound (1C-2-1) (10 μM) of the present invention.
[0018] FIG. 5 is a micrograph showing cells cultivated in a medium containing DMSO, NGF (20 ng/ml), and bis(tetrahydrofuran) compound (1D-2-1) (1 μM) of the present invention.
[0019] FIG. 6 is a micrograph showing cells cultivated in a medium containing DMSO, NGF (20 ng/ml), and bis(tetrahydrofuran) compound (1D-2-1) (10 μM) of the present invention.
DESCRIPTION OF EMBODIMENTS
[0020] Examples of C 1-4 alkyl groups represented by R 1 , R 2 , and R 4 in formula (1) include straight- or branched-chain alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, etc., with methyl, ethyl, and n-butyl being preferable, and methyl being particularly preferable.
[0021] Examples of C 1-5 alkoxy groups represented by R 1 and R 2 in formula (1) include straight- or branched-chain alkoxy groups having 1 to 5 carbon atoms, such as methoxy, ethoxy, isopropoxy, tert-butoxy, prenyl (3-methyl-2-butenyl), etc., with methoxy and ethoxy being preferable, and ethoxy being particularly preferable.
[0022] Examples of aryl C 1-5 alkoxy groups represented by R 1 and R 2 in formula (1) include arylalkoxy groups in which the alkoxy moiety is a straight- or branched-chain alkoxy group having 1 to 4 carbon atoms, such as benzyloxy, 1-phenylethoxy, 2-phenylethoxy, naphthylmethoxy, anthracenylmethoxy, phenanthrenyl methoxy, etc., with benzyloxy being preferable.
[0023] Examples of C 2-5 alkenyloxy groups represented by R 1 and R 2 in formula (1) include straight- or branched-chain alkenyloxy groups having 1 to 5 carbon atoms and 1 to 3 (preferably 1) double bonds, such as allyloxy, 2-butenyloxy, 3-methyl-2-butenyloxy, 3-butenyloxy, 4-pentenyloxy, 3-pentenyloxy, etc., with allyloxy and 3-methyl-2-butenyloxy being preferable.
[0024] Examples of aryl C 2-5 alkenyloxy groups represented by R 1 and R 2 in formula (1) include arylalkenyloxy groups in which the alkenyl moiety is a straight- or branched-chain alkenyl group having 1 to 5 carbon atoms and 1 to 3 (preferably 1) double bonds, such as 3-phenyl-2-propenyloxy, 4-phenyl-2-butenyloxy, 4-phenyl-3-butenyloxy, 5-phenyl-4-pentenyloxy, 5-phenyl-3-pentenyloxy, 4-phenyl-1,3-butadienyloxy, 3-(1-naphthyl)-2-propenyloxy, 3-(2-naphthyl)-2-propenyloxy, etc., with 3-phenyl-2-propenyloxy being preferable.
[0025] Examples of C 1-5 alkylcarbonyl groups represented by R 4 in formula (1) include alkylcarbonyl groups in which the alkyl moiety is a straight- or branched-chain alkyl group having 1 to 4 carbon atoms, such as acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, 3-methyl-2-butenoyl, etc., with acetyl and 3-methyl-2-butenoyl being preferable.
[0026] Examples of aryl C 1-4 alkyl groups represented by R 4 in formula (1) include arylalkyl groups in which the alkyl moiety is a straight- or branched-chain alkyl group having 1 to 4 carbon atoms, such as benzyl, 1-phenethyl, 2-phenethyl, naphthyl methyl, anthracenylmethyl, phenanthrenylmethyl, etc., with benzyl being preferable. The aryl group-forming part of aryl C 1-4 alkyl groups may have 1 to 5 (preferably 1 to 3) substituents, and examples of the substituents on the aryl group include C 1-4 alkyl, C 1-4 alkoxy, C 1-4 alkylcarbonyl, C 1-4 alkoxycarbonyl, amino, nitro, cyano, carboxyl, carbamoyl, halogen atom, etc. C 1-4 alkyl, C 1-4 alkoxy, and C 1-4 alkylcarbonyl described herein are the same as C 1-4 alkyl, C 1-4 alkoxy, and C 1-4 alkylcarbonyl described above. Examples of C 1-4 alkoxycarbonyl groups include alkoxycarbonyl groups in which the alkoxy moiety is a straight- or branched-chain alkoxy group having 1 to 4 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, isopropoxycarbonyl, tert-butoxycarbonyl, etc. Examples of the halogen atom include fluorine, chlorine, bromine, iodine, etc.
[0027] The bis(tetrahydrofuran) compounds represented by formula (1) include the compounds represented by the following formulae (1A), (1B), (1C), and (1D):
[0000]
[0000] wherein R 3 and a carbon-carbon bond between “a” and “b” in each formula are as defined above; R 1d and R 2d represent a C 1-5 alkoxy group, an aryl C 1-5 alkoxy group, a C 2-5 alkenyloxy group, or an aryl C 2-5 alkenyloxy group; and R 1d and R 2c represent a C 1-4 alkyl group.
[0028] More specifically, the bis (tetrahydrofuran) compounds represented by formula (1) include the compounds respectively represented by the following formulae (1A-1), (1A-2), (1B-1), (1B-2), (1C-1), (1C-2), (1D-1), and (1D-2).
[0000]
[0000] wherein R 1c , R 1d , R 2c , R 2 , and R 3 in each formula are as defined above.
[0029] R 3 in the compounds represented by the above formulae (1A-1), (1A-2), (1B-1), (1B-2), (1C-1), (1C-2), (1D-1), and (1D-2) is preferably a hydrogen atom.
[0030] The bis(tetrahydrofuran) compounds represented by formula (1) of the present invention are produced, for example, according to the processes expressed by the following reaction formula-1 to reaction formula-3.
[0000]
[0000] wherein R 3 and a carbon-carbon bond between “a” and “b” in each formula are as defined above; R 5 represents a C 1-4 alkyl group; and R 6 represents a silyl-based protecting group.
[0031] As shown in reaction formula-1, the bis(tetrahydrofuran) compound (1A) of the present invention is produced by reacting a compound represented by formula (2) with a quaternary ammonium fluoride.
[0032] In the above formula (2), R 5 is a straight- or branched-chain C 1-4 alkyl group having 1 to 4 carbon atoms.
[0033] Examples of silyl-based protecting group represented by R 6 include silyl groups such as trimethylsilyl (TMS), triethylsilyl (TES), triisopropylsilyl (TIPS), triisobutylsilyl, tert-butyldimethylsilyl (TBS), tert-butylmethoxyphenylsilyl (TBMPS), tert-butyldiphenylsilyl (TBDPS), tert-hexyldimethylsilyl (TDS), triphenylsilyl (TPS), etc., with tert-butyldimethylsilyl and tert-butyldiphenylsilyl being preferable.
[0034] This reaction is preferably carried out in a solvent. A wide variety of well-known solvents may be used insofar as they do not adversely affect the reaction. Examples of such solvents include aromatic hydrocarbons such as benzene, toluene, xylene, etc.; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, etc.; aliphatic hydrocarbons such as hexane, cyclohexane, petroleum ether, etc.; aliphatic hydrocarbon halides such as dichloromethane, 1,2-chloroethane, chloroform and carbon tetrachloride; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, etc.; ketones such as acetone, 2-butanone, methyl isobutyl ketone, etc.; nitriles such as acetonitrile, propionitrile, benzonitrile, etc.; amides such as N,N-dimethylformamide, hexamethylphosphoric triamide (HMPA), etc.; sulfoxides such as dimethyl sulfoxide, etc.; or a mixed solvent of the above solvents.
[0035] Examples of quaternary ammonium fluorides used in this reaction include tetrabutylammonium fluoride (TBAF), tetraethylammonium fluoride (TEF), ammonium fluoride, etc., with tetrabutylammonium fluoride being preferable.
[0036] The amount of quaternary ammonium fluoride used is not particularly limited, and is suitably selected from a wide range. The amount of quaternary ammonium fluoride used is usually 0.5 to 5 moles, preferably 1.5 to 3 moles, per mole of compound (2).
[0037] The reaction temperature is not particularly limited; however, suitable reaction temperatures are usually within a range of −10° C. to the boiling point of the solvent used, preferably about 0 to about 50° C., and further preferably about 10 to about 40° C. Additionally, the reaction time is usually within 10 hours, preferably from about 30 minutes to about 5 hours, although the reaction time depends on conditions such as the type of raw material compounds, the amount of raw material compounds used, the reaction temperature, etc.
[0038] Bis(tetrahydrofuran) compound (1A) thus obtained is easily isolated and purified from the reaction mixture by typical isolation and purification procedures, such as column chromatography and recrystallization.
[0039] Compound (1B) is produced in accordance with the process expressed by the following reaction formula-2:
[0000]
[0000] wherein R 3 and a carbon-carbon bond between “a” and “b” are as defined above.
[0040] As shown in reaction formula-2, compound (1B) is produced by reacting compound (1A), produced according to the reaction formula-1, with Tebbe's reagent.
[0041] With regard to Tebbe's reagent, reaction conditions, and the like, refer to J. Am. Chem. Soc., 100, 3611 (1978), J. Am. Chem. Soc., 119, 7483 (1997), etc. The process expressed by reaction formula-2 is carried out by, for example, adding Tebbe's reagent dropwise to compound (1A) at room temperature in a solvent such as THF, toluene, or pyridine, preferably in an anhydrous solvent, stirring the mixture for one to several hours at room temperature, adding dropwise thereto an aqueous alkali solution such as a 10% aqueous sodium hydroxide solution while cooling, and filtering and concentrating the resulting reaction solution.
[0042] Compound (1B) thus obtained is easily isolated from a reaction mixture by typical isolation and purification procedures, such as column chromatography and recrystallization.
[0000]
[0000] wherein R 1c , R 1d , R 2c , R 2d , R 3 and a carbon-carbon bond between “a” and “b” are as defined above; and R is the same as R 1c or R 2d , and represents a C 1-5 alkoxy group, an aryl C 1-5 alkoxy group, a C 2-5 alkenyloxy group, or an aryl C 2-5 alkenyloxy group.
[0043] As shown in reaction formula-3, bis(tetrahydrofuran) compounds (10) and (1D) are produced by reacting compound (1B) in an alcohol represented by formula (3), in the presence of an acid catalyst.
[0044] Specific examples of alcohol (3) used in this reaction include, for example, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, prenyl alcohol(3-methyl-2-butenonol), benzyl alcohol, allyl alcohol, cinnamyl alcohol, etc., with methanol, ethanol, n-propyl alcohol, and isopropyl alcohol being preferable, and methanol, ethanol, and n-propyl alcohol being particularly preferable.
[0045] The amount of alcohol (3) used is not particularly limited, and is suitably selected from a wide range. Alcohol (3) is usually used in an amount of 0.8 moles or more, preferably 1.2 moles or more, per mole of compound (1B). As alcohol (3) is usually used as a solvent, alcohol (3) is used in an amount of 1 to 1,000 parts by weight, preferably 10 to 100 parts by weight, per part by weight of compound (1B).
[0046] This reaction may be carried out by further adding a suitable solvent. A wide variety of well-known solvents may be used insofar as they do not adversely affect the reaction. THF, dichloromethane, etc. are examples of usable solvents.
[0047] Examples of catalysts used in this reaction include: pyridinium p-toluenesulfonate (PPTS), pyridinium dodecylbenzenesulfonate, pyridinium tetrafluoroborate, pyridinium hydrogen sulfate, pyridine-SO 3 complex, p-toluenesulfonate, benzenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfonic acid chloride, p-toluenesulfonic acid anhydride, benzoyl chloride, 2,4,6-trimethylbenzoyl chloride, sulfuric acid, amidosulfuric acid (sulfamic acid), sodium hydrogen sulfite, anhydrous zinc chloride, anhydrous ferric chloride(III), anhydrous aluminum chloride, Scandium(III) trifluoromethanesulfonate, yttrium(III) trifluoromethanesulfonate, ytterbium(III) trifluoromethanesulfonate, iodine, etc. Among these, pyridinium salt compounds such as pyridinium p-toluenesulfonate, pyridinium dodecylbenzenesulfonate, pyridinium tetrafluoroborate, and pyridinium hydrogen sulfate are preferable, and pyridinium p-toluenesulfonate is particularly preferable.
[0048] The amount of catalyst used is usually about 0.1 to about 30 wt %, preferably about 5 to about 20 wt %, based on compound (1B).
[0049] The reaction temperature is not particularly limited; however, suitable reaction temperatures are usually within a range of −10° C. to the boiling point of the solvent used, preferably 0 to 50° C., and further preferably in the vicinity of 0° C. Additionally, the reaction time is usually from about 1 to about 60 minutes, preferably about 5 minutes, although the reaction time depends on reaction conditions such as the type of raw material compounds, the amount of raw material compounds used, the reaction temperature, etc.
[0050] Compounds (1C) and (1D) thus obtained are easily isolated from a reaction mixture by typical isolation and purification procedures such as column chromatography and recrystallization.
[0051] This reaction produces a mixture of compounds (1C) and (1D). However, these compounds are easily isolated and purified by isolation procedures such as silica gel column chromatography and the like. As a result, in this reaction, compound (3) is produced in an amount about 2 to about 4 times the amount of compound (4).
[0052] Raw material compound (2) used in reaction formula-1 is producible in accordance with a known method.
[0053] For example, raw material Compound (2) can be produced in accordance with the process expressed by the following reaction formula-4.
[0000]
[0000] wherein R 3 , R 5 and R 6 and a carbon-carbon bond between “a” and “b” are as defined above; and X represents a halogen atom.
[0054] As shown in reaction formula-4, compound (2) is produced by reacting compound (4) with a silyl halide compound represented by formula (5), thereby protecting a hydroxy group of compound (4) with a silyl-based protecting group, then reacting thus-obtained compound (6) with a propynoic acid ester represented by formula (7) in the presence of a strong base such as lithium diisopropylamide (LDA), and further reducing thus-obtained compound (8) using sodium bis(2-methoxyethoxy)aluminum hydride (Red-Al).
[0055] These reactions are carried out by employing known reaction conditions, or in accordance with known methods.
[0056] As is clear from the test example described later, bis(tetrahydrofuran) compound (1) of the present invention is capable of enhancing neurotrophic factor activity. Accordingly, the bis(tetrahydrofuran) compound represented by formula (1) of the present invention, particularly the compounds represented by formulae (1C) and (1D), are effective as neurotrophic factor activity enhancers, and are also effective as active ingredients of a composition used for ameliorating or treating diseases and other conditions caused by neurological disorders.
[0057] Neurotrophic factors contemplated by the present invention include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), glial-derived neurotrophic factor (GDNF), NT-4/5, etc., with NGF or BDNF being preferable, and NGF being particularly preferable.
[0058] The present invention provides a neurotrophic factor activity enhancer or a composition for ameliorating diseases and other conditions caused by neurological disorders (hereinafter also referred to as a “preparation”), wherein the enhancer and the composition contains the bis(tetrahydrofuran) compound represented by formula (1) as an active ingredient.
[0059] The preparation of the present invention may consist of compound (1) alone, or the preparation of the present invention may be a composition prepared by combining compound (1) with any known carriers, additives, or the like into a form suitable for a desired use according to a known method.
[0060] The form of the preparation of the present invention is not particularly limited. Examples of the form include solid preparations such as tablets, powders, granules, pills, powdered syrups, and capsules (hard capsules and soft capsules); paste-like or gel-like preparations such as creams, ointments, and gels; and liquid preparations such as solutions, suspensions, emulsions, syrups, and elixirs.
[0061] The content of bis(tetrahydrofuran) compound (1) in the preparation of the present invention is not particularly limited insofar as the neurotrophic factor activity-enhancing effect is exhibited. Of the total weight (100 wt %) of the preparation, the content of bis(tetrahydrofuran) compound (1) is usually in the range of 0.001 to 99 wt %, preferably 0.01 to 50 wt %, more preferably 0.1 to 30 wt %.
[0062] The preparation of the present invention contains bis(tetrahydrofuran) compound (1) in an amount effective for exhibiting a neurotrophic factor activity-enhancing effect. The preparation may be combined with one or more other components within a range in which the above-described effect is not impaired. Such other components are not limited insofar as they are pharmacologically and pharmaceutically acceptable. Such components include carriers generally used for production of preparations, for example, diluents, binders, dispersants, thickeners, lubricants, pH adjusters, solubilizers, etc. Other components include antibiotics, antimicrobial agents, bactericides, antiseptics, builders, bleaches, enzymes, chelating agents, antifoaming agents, colorants (such as dye compounds and pigments), softeners, humectants, surfactants, antioxidants, perfumes, flavoring agents, odor improving agents, solvents, etc. Further, known neurotrophic factors, neurotrophic factor-like active substances, or neurotrophic factor activity enhancers or activators other than the enhancers of the present invention may be added to the preparation of the present invention.
[0063] Methods of the use of the present preparation include a method in which the preparation is introduced into the body via oral administration, instillation, injection, etc., and a method in which the preparation is locally applied to the affected area.
[0064] Because the amount used of the preparation of the present invention depends on the formulation, administration (use), and the like, the amount is not necessarily determined; however, an appropriate daily dose can be suitably set according to the age and symptoms of the patient, and is usually within a range of 1 ng to 100 mg, preferably 10 ng to 50 mg, per 1 kg of human adult body weight, in terms of dosage of bis(tetrahydrofuran) compound (1) of the present invention. The preparations are preferably administrated in one to several divided doses per day.
Example
[0065] The present invention is described below in further detail with reference to production examples, a preparation example, and a test example of bis(tetrahydrofuran) compound (1) of the present invention; however, the present invention is not limited thereto. “Me” used hereinbelow refers to methyl.
[0066] Measuring Device Used
[0067] The nuclear magnetic resonance spectrum (hereinbelow referred to as “NMR”) was measured using Varian Gemini-200, Mercury-300, Unity-600 and JOEL JMN-ECP-400. A sample was measured using tetramethyl silane (TMS), chloroform (CHCl 3 ) or benzene (C 6 H 6 ) as the internal standard. The chemical shift (δ) was indicated in ppm, and the coupling constant (J) was indicated in Hz. The signals were described with the following symbols: “s” for singlet, “d” for doublet, “t” for triplet, “q” for quartet, “m” for multiplet, and “br” for broad.
[0068] Normal-phase silica gel column chromatography was performed using Merck Kieselgel 60 (70-230 mesh ASTM) and Kanto Chemical normal-phase silica gel 60 (spherical, 63-210 μm), and reversed-phase column chromatography was performed using a Nacalai Tesque Cosmosil 140 C 18 -PREP.
[0069] High-performance liquid chromatography (HPLC) was performed using a JASCO 880-PU chromatographic pump, and the results were expressed in v/w ratio using a JASCO spectrometer. The melting point (hereinafter sometimes referred to as “mp”) was measured using a YANACO micro melting point apparatus.
[0070] The infrared absorption spectrum (hereinafter may be referred to as “IR”) was measured by the reflection method using a FT-IR410.
[0071] The mass analysis spectrum (hereinafter may be referred to as “MS”) was measured by the electron impact ionization method (hereinafter may be referred to as “EI”), the chemical ionization method (hereinafter may be referred to as “CI”), or the fast atom bombardment method (hereinafter may be referred to as “FAB”), using a JEOL AX-500.
[0072] X-ray crystallographic analysis (X-ray) was carried out using a Mac Science DIP-2020 X-ray analyzer. Mo Ka radiation was used as the X-ray source. Reflection data were collected, and analysis was carried out using a MAC Science crystal analysis program.
[0073] Solvent and Reagent Used Unless otherwise specifically stated, the reactions were carried out under Ar (argon) atmosphere, and special grade solvents or dehydrated solvents were used as reaction solvents. Further, the anhydrous tetrahydrofuran (THF) used was anhydrous tetrahydrofuran (stabilizer-free) produced by Kanto Chemical Co., Inc.; the anhydrous dichloromethane used was anhydrous dichloromethane produced by Kanto Chemical Co., Inc.
[0074] The product obtained upon solvent extraction was and dried using anhydrous magnesium sulfate (MgSO 4 ) or anhydrous sodium sulfate (Na 2 SO 4 ). The solvent was evaporated with an evaporator under reduced pressure.
[0075] Thin layer chromatography (TLC) for analysis was performed using Merck Kieselgel 60F 254 (0.25 mm, 0.5 mm). Spots were detected by irradiation using a 254 nm UV lamp, or by spraying with an anisaldehyde-sulfuric acid color-developing agent, and then heating.
Production Example 1
[0076]
[0077] TBAF (1.0 M, THF, 13,78 ml, 13.78 mmol) was added dropwise to an anhydrous THF solution (45 ml) of the above-described ester compound (2A) (1.5 g, 4.59 mmol) that corresponds to raw material compound (2) of the present invention, and the mixture was stirred for 30 minutes at room temperature. Saturated saline was added thereto, and the mixture was thrice-extracted with ethyl acetate. The organic layer thus obtained was dried with anhydrous sodium sulfate, filtered, and then concentrated. The residue was purified by column chromatography (silica gel 30 g, n-hexane:ethyl acetate=1:1) to afford bis(tetrahydrofuran) compound (1A-2-1) of the present invention (757.5 mg, yield 92%).
[0078] FTIR (neat) 3526, 2945, 2319, 1790 cm −1
[0079] 1 H NMR (300 MHz, CDCl 3 ) δ ppm: 1.49-1.59 (1H, m), 1.83-1.92 (2H, m), 1.96-2.32 (3H, m), 2.79 (2H, d, J=3.6 Hz), 4.31 (1H, dd, J=1.8, 3.6 Hz), 4.39 (1H, dd, J=2.1, 12.0 Hz), 4.57 (1H, dq, J=2.1, 12.0 Hz), 5.93 (1H, m)
[0080] 13 C NMR (75 MHz, CDCl 3 ) δ ppm: 17.2t, 24.1t, 29.1t, 36.9t, 69.8t, 81.9d, 88.1s, 125.4d, 134.6s, 174.83s
[0081] MS (CI) m/z 181 (M + +H)
[0082] HRMS (CI) m/z calcd for C 10 H 13 O 3 (M + +H): 181.0865, found 181.0862
[0083] m.p. 68-71° C.
Production Example 2
[0084]
[0085] Anhydrous THF (6 ml), anhydrous toluene (2 ml), anhydrous pyridine (40 μl, 0.49 mmol) and bis(tetrahydrofuran) compound (1A-2-1) (400 mg, 2.197 mmol) of the present invention obtained in Production Example 1 were placed in a dried two-neck flask. Tebbe's reagent (0.5 M, toluene, 8.79 ml, 4.39 mmol) was further added dropwise thereto at room temperature. This mixture was stirred for one hour at room temperature, and then cooled to −20° C. A 10% aqueous sodium hydroxide solution was added dropwise thereto, and the mixture was then filtered through Celite and concentrated. The residue thus obtained was used in the next process without purification.
[0086] The thus-obtained residue was dissolved in methanol (30 ml), and PPTS (301.46 mg, 1.2 mmol) was added thereto at room temperature, and the mixture was stirred for 5 hours. The mixture was cooled to 0° C., and then saturated sodium hydrogen carbonate solution was added thereto, after which the mixture was thrice-extracted with ethyl acetate. The organic layer thus obtained was dried with anhydrous sodium sulfate, filtered, and then concentrated. The residue was purified by column chromatography (silica gel 1.5 g, the ratio of n-hexane to ethyl acetate=3:1) to give a colorless oily diastereomer mixture of (1C-2-1) and (1D-2-1) (369 mg, yield 80%). Next, the thus-obtained diastereomer mixture was separated into compound (1C-2-1) and compound (1D-2-1) by normal-phase HPLC (Cosmosil 5SL-II Water (20×250), the ratio of n-hexane to ethyl acetate=6:1, 17.0 ml/min, detector: RI).
[0087] Physical Properties of Compound (1C-2-1):
[0088] FTIR (neat) 2985, 2943, 2863, 2830, 1698 cm −1
[0089] 1 H NMR (300 MHz, C 6 D 6 ) δ ppm: 1.13 (1H, dt, J=3.0, 12.9 Hz), 1.43 (3H, s), 1.52-1.60 (1H, m), 1.64-1.79 (1H, m), 1.85-2.00 (2H, m), 2.14 (1H, dt, J=3.3, 9.7 Hz), 2.26 (1H, dd, J=1.7, 14.3 Hz), 2.24 (1H, dd, J=5.8, 14.3 Hz), 3.15 (3H, s), 4.16 (1H, dq, J=1.7, 11.5 Hz), 4.23 (1H, dd, J=1.7, 5.8 Hz), 4.55 (1H, dq, J=3.0, 11.5 Hz), 5.31 (1H, brs)
[0090] 13 C NMR (150 MHz, C 6 D 6 ) δ ppm: 18.7t, 23.4q, 24.7t, 30.2t, 47.7t, 48.7q, 69.8t, 87.6s, 88.2d, 109.9s, 121.04d, 139.8s
[0091] MS (CI) m/z 209 (M + -H)
[0092] HRMS (CI) m/z calcd for C 12 H 17 O 3 (M + -H): 209.1205, found 209.1155.
[0093] Physical Properties of Compound (1D-2-1):
[0094] FTIR (neat) 2984, 2939, 2870, 2829, 1431, 1375 cm −1
[0095] 1 H NMR (300 MHz, C 6 D 6 ) δ ppm: 1.16 (1H, ddd, J=3.3, 12.6, 13.8 Hz), 1.30 (3H, s), 1.46-1.55 (1H, m), 1.67-1.83 (3H, m), 1.87-2.09 (2H, m), 2.52 (1H, d, J=14.1 Hz), 3.20 (3H, s), 4.26 (1H, d, J=6.0 Hz), 4.24 (1H, dd, J=1.4, 10.7 Hz), 4.83 (1H, dq, J=2.1, 10.7 Hz), 5.36 (1H, brs)
[0096] 13 C NMR (150 MHz, C 6 D 6 ) δ ppm: 18.5t, 23.6q, 24.5t, 32.2t, 47.3t, 48.7q, 70.7t, 87.6s, 87.9d, 108.3s, 121.0d, 140.3s
[0097] MS (CI) m/z 209 (M + -H)
[0098] HRMS (CI) m/z calcd for C 12 H 17 O 3 (M + -H): 209.1178, found 209.1177.
Production Example 3
[0099]
[0100] The tetrahydrofuran compound (1A-2-1) (1 g, 5.5 mmol) of the present invention obtained in Production Example 1 above was dissolved in methanol (55 ml), and palladium-activated carbon (290 mg as activated carbon palladium) was added thereto, and the mixture was stirred for 12 hours at room temperature under 1 atm of hydrogen. The reaction mixture thus obtained was filtered and then concentrated. The residue was purified by column chromatography (silica gel 20 g, the ratio of n-hexane to ethyl acetate=3:1) to afford, as a colorless oily product, the tetrahydrofuran of the present invention compound (1A-1-1) (838 mg, yield 83%).
[0101] FTIR (neat) 2938, 2862, 1773, 1451 cm −1
[0102] 1 H NMR (600 MHz, CDCl 3 ) δ ppm: 1.26-1.38 (3H, m), 1.64-1.77 (1H, m), 1.84-1.94 (4H, m), 2.31 (1H, quintet, J=4.9 Hz), 2.67 (1H, d, J=18.4 Hz), 2.76 (1H, dd, J=5.5, 18.4 Hz), 3.65 (1H, d, J=8.5 Hz), 4.07 (1H, dd, J=4.4, 8.5 Hz), 4.55 (1H, d, J=5.5 Hz)
[0103] 13 C NMR (75 MHz, CDCl 3 ) δ ppm: 23.1t, 23.8t, 28.3t, 30.0t, 36.4t, 44.0d, 73.7t, 78.0d, 95.4s, 175.4s
[0104] MS (CI) m/z 183 (M + +H)
[0105] HRMS (CI) m/z calcd for C 10 H 15 O 3 (M + +H): 183.1021, found 183.1024.
Production Example 4
[0106]
[0107] Anhydrous THF (5 ml), anhydrous toluene (1.6 ml), anhydrous pyridine (30 ml, 0.37 mmol) and bis(tetrahydrofuran) compound (1A-1-1) (300 mg, 1.66 mmol) of the present invention obtained in Production Example 3 above were placed in a dried two-neck flask. Tebbe's reagent (0.5 M, toluene, 6.6 ml, 3.29 mmol) was further added dropwise thereto at room temperature. This mixture was stirred for 2 hours at room temperature, and then cooled to −20° C. A 10% aqueous sodium hydroxide solution was added dropwise thereto, and the mixture was then filtered through Celite and concentrated. The residue thus obtained was used in the next process without purification.
[0108] The thus-obtained residue was dissolved in methanol (16 ml), PPTS (164.8 mg, 0.66 mmol) was added thereto at room temperature, and the mixture was stirred for 5 hours. The mixture was cooled to 0° C., and then saturated sodium hydrogen carbonate solution was added thereto, after which the mixture was thrice-extracted with ethyl acetate. The organic layer thus obtained was dried with anhydrous sodium sulfate, filtered, and then concentrated. The residue was purified by column chromatography (silica gel 10 g, the ratio of n-hexane to ethyl acetate=2:1) to give a colorless oily diastereomer mixture of (1D-1-1) and (1C-1-1) (278 mg, yield 80%). Next, the thus-obtained diastereomer mixture was separated into (1D-1-1) and (C-1-1) by normal-phase HPLC (Cosmosil 5SL-II Water (20×250), the ratio of n-hexane to ethyl acetate=6:1, 17.0 ml/min, detector: RI).
[0109] Physical Properties of Compound (1C-1-1):
[0110] FTIR (neat) 2984, 2934, 2860, 2826, 1451, 1375 cm −1
[0111] 1 H NMR (300 MHz, C 6 D 6 ) δ ppm: 0.99 (2H, dt, J=3.0, 11.0 Hz), 1.06-1.24 (1H, m), 1.40 (3H, s), 1.45-1.67 (4H, m), 1.91 (1H, dt, J=5.0, 11.5 Hz), 2.12 (1H, brd, J=11.5 Hz), 2.21 (1H, d, J=14.4 Hz), 2.28 (1H, dd, J=6.3, 14.4 Hz), 3.17 (3H, s), 3.43 (1H, d, J=7.7 Hz), 4.05 (1H, dd, J=4.5, 7.7 Hz), 4.40 (1H, dd, J=1.1, 6.3 Hz)
[0112] 13 C NMR (75 MHz, C 6 D 6 ) δ ppm: 22.8q, 24.3t, 24.7t, 29.3t, 32.1t, 45.8d, 48.3t, 48.7q, 73.4t, 83.2d, 94.3s, 108.9s MS (CI) m/z 213 (M + +H)
[0113] HRMS (CI) m/z calcd for C 12 H 20 O 3 (M ÷ +H):213.1491, found 213.1471.
[0114] Physical Properties of Compound (1D-1-1):
[0115] FTIR (neat) 2982, 2934, 2856, 2826, 1449, 1375 cm −1
[0116] 1 H NMR (300 MHz, C 6 D 6 ) δ ppm: 0.88-1.09 (2H, m), 1.21 (1H, dq, J=3.4, 13.2 Hz), 1.31 (3H, s), 1.31-1.62 (5H, m), 1.68 (1H, dd, J=5.3, 14.1 Hz), 1.88 (1H, dt, J=5.3, 11.4 Hz), 2.48 (1H, d, J=14.1 Hz), 3.22 (3H, s), 3.47 (1H, d, J=7.5 Hz), 4.22 (1H, d, J=5.4 Hz), 4.37 (1H, dd, J=4.3 Hz)
[0117] 13 C NMR (75 MHz, C 6 D 6 ) δ ppm: 24.3q, 24.6t, 24.7t, 29.8t, 33.0t, 46.0d, 46.4t, 49.0q, 74.0t, 83.2d, 95.2s, 108.1s
[0118] MS (CI) m/z 211 (M + +H)
[0119] HRMS (CI) m/z calcd for C 12 H 19 O 3 (M + -H): 211.1334, found 211.1353.
Production Example 5
[0120] Anhydrous THF (5 ml), anhydrous toluene (1.6 ml), anhydrous pyridine (30 ml, 0.37 mmol) and bis(tetrahydrofuran) compound (1A-1-1) (300 mg, 1.66 mmol) of the present invention obtained in Production Example 3 above were placed in a dried two-neck flask. Tebbe's reagent (0.5 M, toluene, 6.6 ml, 3.29 mmo) was further added dropwise thereto at room temperature. This mixture was stirred for 2 hours at room temperature, and then cooled to −20° C. A 10% aqueous sodium hydroxide solution was added dropwise thereto, and the mixture was then filtered through Celite and concentrated. The residue thus obtained was used in the next process without purification.
[0121] The thus-obtained residue was dissolved in benzyl alcohol (16 ml), and PPTS (164.8 mg, 0.66 mmol) was added thereto at room temperature, and the mixture was stirred for 5 hours. The mixture was cooled to 0° C., and then saturated sodium hydrogen carbonate solution was added thereto, after which the mixture was thrice-extracted with ethyl acetate. The organic layer thus obtained was dried with anhydrous sodium sulfate, filtered, and then concentrated. The residue was purified by column chromatography (silica gel 10 g, the ratio of n-hexane to ethyl acetate=2:1) to give a colorless oily diastereomer mixture of (1C-2-2) and (1D-2-2) (278 mg, yield 80%). Next, the thus-obtained diastereomer mixture was separated into the (1C-2-2) and (1D-2-2) shown below by normal-phase HPLC (Cosmosil 5SL-II Water (20×250), the ratio of n-hexane to ethyl acetate=6:1, 17.0 ml/min, detector: RI).
[0000]
[0122] Physical Properties of Compound (1C-2-2):
[0123] 1 H NMR (600 MHz in C 6 D 6 ) δ ppm: 1.07 (1H, dt, 3.9, 14.4 Hz), 1.50 (1H, m), 1.52 (3H, s), 1.70 (1H, m), 1.89 (2H, m), 2.16 (1H, dt, J=3.0, 14.4 Hz), 2.35 (1H, dd, J=2.4, 15.0 Hz), 2.51 (1H, dd, J=6.0, 15.0 Hz), 4.17 (1H, dd, J=2.4, 12.0 Hz), 4.20 (1H, dd, J=2.4, 7.2 Hz), 4.48 (1H, d, J=12.0 Hz), 4.55 (1H, dq, J=, 3.0, 12.0 Hz), 4.68 (1H, d, J=12.0 Hz), 5.31 (1H, br s), 7.11 (1H, t, J=8.4 Hz), 7.20 (2H, t, J=8.4 Hz), 7.34 (2H, d, J=8.4 Hz)
[0124] 13 C NMR (150 MHz in C 6 D 6 ) δ ppm: 18.60t, 24.48q, 24.68t, 30.05t, 47.98t, 63.96t, 69.92t, 87.97s, 88.14d, 110.12s, 121.17d, 127.32d, 127.72d (2C), 128.48d (2C), 139.73s, 139.88s.
[0125] Physical Properties of Compound (1D-2-2):
[0126] 1 H NMR (600 MHz in C 6 D 6 ) δ ppm: 1.16 (1H, ddd, J=3.3, 12.6, 14.6 Hz), 1.37 (3H, s), 1.53 (1H, m), 1.73 (2H, dt, J=3.3, 11.4 Hz), 1.76 (2H, dd, J=5.6, 14.3 Hz), 1.77 (1H, m), 1.74 (1H, br d, J=11.4 Hz), 2.24 (1H, m), 2.62 (1H, d, J=14.3 Hz), 4.14 (1H, dd, J=1.6, 11.4 Hz), 4.22 (1H, d, J=5.8 HZ), 4.59 (1H, d, J=12.0 Hz), 4.70 (1H, d, J=12.0 Hz), 4.79 (1H, ddt, J=2.2, 3.0, 11.4 Hz), 5.31 (1H, br s), 7.08 (1H, t, J=7.4 Hz), 7.18 (2H, t, J=8.4 Hz), 7.38 (2H, d, J=7.4 Hz)
[0127] 13 C NMR (150 MHz in C 6 D 6 ) δ ppm: 18.48t, 24.57t, 24.75q, 32.16t, 47.48t, 63.82t, 70.74t, 87.90d, 87.95s, 108.77s, 121.16d, 127.14d, 127.84d (2C), 128.00d (2C), 139.98s, 140.21s.
Production Example 6
[0128] A colorless oily diastereomer mixture of (1C-2-3) and (1D-2-3) was obtained in a similar manner as in Production Example 5, except that ethyl alcohol (16 ml) was used instead of benzyl alcohol. Next, the diastereomer mixture thus obtained was separated into the (1C-2-3) and (1D-2-3) shown below by normal-phase HPLC (Cosmosil 5SL-II Water (20×250), the ratio of n-hexane to ethyl acetate=6:1, 17.0 ml/min, detector: RI).
[0000]
[0129] Physical Properties of Compound (1C-2-3):
[0130] 1 H NMR (600 MHz in C 6 D 6 ) δ ppm: 1.11 (3H, t, J=6.9 Hz), 1.15 (1H, ddd, J=3.0, 12.9, 13.2 Hz), 1.48 (3H, s), 1.58 (1H, m), 1.74 (1H, m), 1.90 (2H, m), 2.19 (1H, dt, J=3.3, 13.2 Hz), 2.31 (1H, dd, J=1.6, 14.0 Hz), 2.67 (1H, dd, J=5.8, 14.0 Hz), 2.67 (1H, dd, J=5.8, 14.0 Hz), 3.37 (1H, dq, J=6.9, 16.2 Hz), 3.62 (1H, dq, J=3.9, 16.2 Hz), 4.17 (1H, ddt, J=1.6, 1.9, 13.8 Hz), 4.24 (1H, dd, J=1.4, 6.0 Hz), 4.54 (1H, dddd, J=2.1, 3.0, 8.4, 13.8 Hz), 5.31 (1H, br s)
[0131] 13 C NMR (150 MHz in C 6 D 6 ) δ ppm: 15.89q, 18.58t, 24.24q, 24.69t, 30.31t, 47.99t, 56.72t, 69.87t, 87.53s, 88.22d, 109.70s, 120.96d, 139.89s.
[0132] Physical Properties of Compound (1D-2-3):
[0133] 1 H NMR (300 MHz in C 6 D 6 ) δ ppm: 1.14 (3H, t, J=6.9 Hz), 1.17 (1H, m), 1.34 (3H, s), 1.53 (1H, m), 1.70-2.17 (5H, m), 2.54 (1H, d, J=14.4 Hz), 3.45 (1H, dq, J=1.9, 6.9 Hz), 3.65 (1H, dq, J=1.9, 6.9 Hz), 4.23 (1H, d, J=6.0 Hz), 4.25 (1H, d, J=11.1 HZ), 4.93 (1H, dq, J=2.1, 11.1 Hz), 5.37 (1H, br s).
Production Example 7
[0134] A colorless oily diastereomer mixture of (1C-2-4) and (1D-2-4) was obtained in a similar manner as in Production Example 5, except that n-butyl alcohol (16 ml) was used instead of benzyl alcohol. Next, the diastereomer mixture thus obtained was separated into the (1C-2-4) and (1D-2-4) shown below by normal-phase HPLC (Cosmosil 5SL-II Water (20×250), the ratio of n-hexane:ethyl acetate=6:1, 17.0 ml/min, detector: RI).
[0000]
[0135] Physical Properties of Compound (1C-2-4):
[0136] 1 H NMR (600 MHz in C 6 D 6 ) δ ppm: 0.88 (3H, t, J=7.4 Hz), 1.13 (1H, ddd, J=3.0, 12.6, 13.8 Hz), 1.37 (2H, m), 1.50 (3H, s), 1.55-1.60 (3H, m), 1.72 (1H, m), 1.92 (2H, m), 2.18 (1H, dt, J=3.0, 12.6 Hz), 2.32 (1H, dd, J=1.4, 14.4 Hz), 2.44 (1H, dd, J=5.6, 14.4 Hz), 3.38 (1H, dt, J=6.3, 9.0 Hz), 3.62 (1H, dt, J=6.6, 9.0 Hz), 4.17 (1H, dd, J=1.9, 9.8 Hz), 4.19 (1H, dd, J=1.1, 5.4 Hz), 4.54 (1H, m), 5.30 (1H, br s)
[0137] 13 C NMR (150 MHz in C 6 D 6 ) δ ppm: 14.12q, 18.63t, 19.84t, 24.42q, 24.72t, 30.22t, 32.68t, 47.93t, 61.09t, 69.97t, 87.58s, 88.26d, 109.76s, 120.93d, 139.95s.
[0138] Physical Properties of Compound (1D-2-4):
[0139] 1 H NMR (600 MHz in C 6 D 6 ) δ ppm: 0.84 (3H, t, J=7.4 Hz), 1.16 (1H, ddd, J=3.6, 12.6, 14.4 Hz), 1.34 (2H, m), 1.36 (3H, s), 1.49-1.62 (3H, m), 1.71-1.80 (3H, m), 1.92 (1H, m), 2.00 (1H, m), 2.54 (1H, d, J=14.4 Hz), 3.44 (1H, dt, J=6.9, 9.0, Hz), 3.53 (1H, ddd, J=5.8, 7.2, 9.0 Hz), 4.20 (1H, d, J=5.6 Hz), 4.26 (1H, dd, J=1.6, 10.8 Hz), 4.92 (1H, ddt, J=2.2, 3.6, 10.8, Hz), 5.37 (1H, br s)
[0140] 13 C NMR (150 MHz in C 6 D 6 ) δ ppm: 14.14q, 18.50t, 19.85t, 24.59t, 24.81q, 32.25t, 32.69t, 47.49t, 61.49t, 70.70t, 87.56s, 88.03d, 108.48s, 120.95d, 140.47.
Production Example 8
[0141] A colorless oily diastereomer mixture of (1C-2-5) and (1D-2-5) was obtained in a similar manner as in Production Example 5, except that allyl alcohol (16 ml) was used instead of benzyl alcohol.
[0000]
[0142] Physical Properties of a Diastereomer Mixture of Compound (1C-2-5) and Compound (1D-2-5):
[0143] 1 H NMR (300 MHz in C 6 D 6 ) δ ppm: 1.23 (1H, dt, J=3.0, 13.2 Hz, major), 1.43 (3H, s, minor), 1.55 (3H, s, major), 1.60-2.01 (m), 2.29 (1H, dt, J=3.6, 12.9 Hz), 2.40 (1H, dd, J=1.5, 14.4 Hz), 2.59 (1H, dd, J=5.7, 14.4 Hz), 2.66 (1H, d, J=14.4 Hz), 4.01 (1H, ddt, J=1.8, 4.8, 12.9 Hz, major), 4.89 (1H, ddt, J=1.8, 4.8, 13.2 Hz, minor), 4.19-4.35 (m), 4.62 (1H, dq, J=3.0, 11.4 Hz), 5.00 (1H, dq, J=2.4, 11.1 Hz, minor), 5.14 (1H, dq, 1.8, 10.5 Hz, major), 5.34-5.46 (2H, m), 6.0 (1H, m).
Production Example 9
[0144] A colorless oily diastereomer mixture of (1C-2-6) and (1D-2-6) was obtained in a similar manner as in Production Example 5, except that prenyl alcohol (16 ml) was used instead of benzyl alcohol.
[0000]
[0145] Physical Properties of a Diastereomer Mixture of Compound (1C-2-6) and Compound (1D-2-6):
[0146] 1 H NMR (200 MHz in C 6 D 6 ) δ ppm: 1.15 (1H, dt, J=3.2, 12.8 Hz), 1.51 (3H, s), 1.54 (3H, s), 1.61 (3H, s), 1.7-2.0 (m), 2.26 (1H, dt, J=3.0, 13.0 Hz), 2.30 (1H, dd, J=1.6, 14.0 Hz), 2.51 (1H, dd, J=5.6, 14.0 Hz), 4.03 (1H, dd, J=6.6, 11.2 Hz), 4.12-4.29 (m), 4.53 (1H, dq, J=3.0, 11.4 Hz), 5.33 (1H, br s), 5.49 (1H, br t, J=6.8 Hz).
Production Example 10
[0147] A colorless oily diastereomer mixture of (1C-2-7) and (1D-2-7) was obtained in a similar manner as in Production Example 5, except that cinnamyl alcohol (16 ml) was used instead of benzyl alcohol.
[0000]
[0148] Physical Properties of a Diastereomer Mixture of Compound (1C-2-7) and Compound (1D-2-7):
[0149] 1 H NMR (200 MHz in C 6 D 6 ) δ ppm: 1.15 (1H, m), 1.28-2.05 (m), 1.39 (3H, s, minor), 1.52 (3H, s, major), 2.25 (1H, dt, J=3.0, 13.0 Hz), 2.34 (1H, dd, J=1.6, 14.4 Hz), 2.54 (1H, dd, J=5.8, 14.4 Hz), 2.61 (1H, d, J=14.4 Hz), 4.02-4.37 (m), 4.55 (1H, dq, J=3.0, 11.4 Hz, major), 4.95 (1H, dq, J=3.0, 11.0 Hz, minor), 5.33 (1H, br s), 6.27 (1H, dt, J=5.4, 16.0 Hz, major), 6.29 (1H, dt, J=5.4, 15.8 Hz, minor), 6.62 (1H, br d, J=16.0 Hz, major), 6.66 (1H, dt, J=1.8, 16.0 Hz, minor), 6.99-7.16 (m), 7.26 (2H, dt, J=1.4, 6.2 Hz).
Test Example
Preparation of Medium and Reagent
[0150] Preparation of Dulbecco's Modified Eagle Medium (DMEM)/10% HS, 5% FBS
[0151] Donor horse serum (HS) (5 ml), fetal bovine serum (FBS) (2.5 ml), and penicillin-streptomycin (0.5 ml) were added to DMEM (total amount: 50 ml), and thereby DMEM/10% HS, 5% FBS were prepared.
[0152] Preparation of DMEM/2% HS, 1% FBS
[0153] HS (1 ml), FBS (0.5 ml) and penicillin-streptomycin (0.5 ml) were added to DMEM (total amount: 50 ml), and thereby DMEM/2% HS, 1% FBS was prepared.
[0154] Preparation of 0.25% trypsin/PBS (Phosphate Buffered Saline)
[0155] 2.5% trypsin was diluted 10-fold with PBS, and thereby 0.25% trypsin/PBS was prepared.
[0156] Preparation of 0.4% Trypan Blue
[0157] 0.4% trypan blue was prepared by dissolving 0.2 g of trypan blue in 50 ml PBS.
[0158] Preparation of Sample
[0159] When the solvent was ethanol, the concentrations were targeted at 1 mM, 0.1 mM, and 10 mM. A sample at 1 mM concentration was prepared first. When the amount of sample was 1 mg, the sample was dissolved in 100% ethanol (1/molecular weight×1,000)/2 ml, and an equal amount of Milli-Q (1/molecular weight×1,000)/2 ml was added thereto, after which the sample was filtered through a 0.45 mM filter into a sample tube.
[0160] A sample at 0.1 mM concentration was prepared by diluting 1 mM solution 10-fold with 50% ethanol. Likewise, a sample at 10 mM concentration was prepared from 0.1 mM solution.
[0161] When the solvent was DMSO, the concentrations were targeted at 10 mM, 1 mM, and 0.1 mM.
[0162] When the sample is prepared in ethanol, the sample is diluted 100-fold with the medium; and when the sample is prepared in DMSO, the sample is diluted 1.000-fold in the medium. The actual concentrations of the sample were thus 10 mM, 1 mM, and 0.1 mM both when the sample was prepared in ethanol and when the sample was prepared in DMSO.
[0163] Neurite Outgrowth Measuring Method
[0164] Measurement was carried out using the following equipment and software.
[0000] Research-level inverted microscope 1×70 (Olympus Corporation)
High-resolution CCD cooled digital color camera C4742-95-12SC (Hamamatsu Photonics K.K.)
Lumina Vision fluorescence imaging analysis system and MacSCOPE image analysis package (Mitani Corporation)
[0165] Statistical Processing
[0166] Statistical processing of obtained data was carried out using “Origin ver. 7.0” (OriginLab, USA) and Mac Statistical Analysis. The significant difference was determined using Student's T-test and Dunnett's T-test.
[0167] Experimental Test Material and Reagent
[0168] Cell
[0169] Pheochromocytoma (PC12) cells were purchased from the Health Science Research Resources Bank of the Japan Health
[0170] Sciences Foundation. Cell number: JCRB0733, product name: PC-12.
[0171] Reagents
[0172] DMEM, penicillin-streptomycin, HS, FBS, trypsin, and nerve growth factor (NGF) were obtained from GIBCOBAL. DULBECCO'S PBS was obtained from Dainippon Pharma Co., Ltd. Ethanol and dimethyl sulfoxide (DMSO) were obtained from Nacalai Tesque, Inc.
[0173] Experimental Test Method
[0174] Cell Culture
[0175] PC12 cells were cultivated in a medium having a composition including DMEM/10% HS, 5% FBS, 50 IU/ml penicillin, and 50 mg/ml streptomycin, in a culture flask coated with rat tail-derived collagen, in an incubator (95% humidity, 5% carbon dioxide). When the cell density becomes obviously too low, or when the cells overproliferate, the cells would be under load, requiring a longer time for proliferation and/or causing the cells to dye out. Thus, the cells were subcultured such that the cells would be present at a density of about 80% in the flask. When cells were subcultured or when activity evaluation tests were carried out, the cells were treated with trypsin (0.25%, 5 min.) to obtain a cell suspension, which was then seeded into a collagen-coated culture flask or plate.
[0176] Cell Isolation and Seeding
[0177] The condition of the PC12 cells was observed; it was confirmed that at least 50% of the PC12 cells were fused. The plate was coated with rat tail-derived collagen; on the following day, the plate was washed twice with Milli-Q water. Then, a medium having a composition including DMEM/10% HS, 5% FBS, 50 IU/ml penicillin, and 50 mg/ml streptomycin was prepared.
[0178] The medium in the culture flask was removed by suction. The PC12 cells were washed twice with PBS (5 mL), and trypsin (3 mL) was added thereto, which was then left to stand for about 5 minutes. A cell suspension was obtained by pipetting. In order to inhibit the activity of the trypsin, the cell suspension was transferred to a 50 mL centrifuge tube containing a serum-containing medium (2 mL). The total amount was adjusted to 10 mL with PBS, and the cell suspension was centrifuged (1,000 rpm×5 min). After centrifuging, the supernatant liquid was removed by suction using a pump, PBS (10 mL) was added thereto, and pipetting was carried out several times using a bent-tip Komagome pipette. After pipetting, the cell suspension was centrifuged again, and a similar operation was repeated twice. After the second centrifuging, the prepared medium (5 mL) was added to the tube, pipetting was carried out several times using a bent-tip Komagome pipette, and a cell suspension was thereby obtained.
[0179] Screening Method
[0180] The cells were isolated by the method described above, and seeded into a 48-well plate such that the cell density was 2,000 cells/cm 2 in the medium having a composition including DMEM/10% HS, 5% FBS. After the cells were cultured for 24 hours in an incubator, the medium was exchanged with a sample-containing medium including DMEM/2% HS, 1% FBS and NGF (10 ng/ml) as well as a medium including DMEM/2% HS, 1% FBS and NGF (10 ng/ml). Cell culturing continued in the incubator, and the cell form was observed under a microscope for one week from the day following the medium exchange. During this period, when neurite outgrowth was observed, the neurite outgrowth was photographed using a digital camera.
[0181] The sample was prepared using 50% ethanol and DMSO. The sample prepared using 50% ethanol was diluted 100-fold in the medium, and the sample prepared using DMSO was diluted 1.000-fold in the medium.
[0182] Judgment on Neurite Outgrowth Activity
[0183] As for the determination of neurite outgrowth activity, when a cell with at least one neurite longer than the cell body was observed, the cell was counted as a neurite formation. The neurite length was determined by a comparison between the control (50% ethanol or 0.1% DMSO), and cells that underwent differentiation induced by adding NGF (10 ng/ml).
[0184] Activity Test Result
[0000]
[0185] FIG. 1 is a micrograph showing cells cultivated in a medium containing DMSO. FIG. 2 is a micrograph showing cells cultivated in a medium containing DMSO and NGF (20 ng/ml). FIG. 3 is a micrograph showing cells cultivated in a medium containing DMSO, NGF (20 ng/ml), and compound (1C-2-1) (1 μM). FIG. 4 is a micrograph showing cells cultivated in a medium containing DMSO, NGF (20 ng/ml), and compound (1C-2-1) (10 μM). As is clear from FIGS. 3 and 4 , under the presence of DMSO and NGF (20 ng/ml), the sample including 1 μM or 10 μM of compound (1C-2-1) resulted in further enhanced neurite outgrowth activity, compared with the sample without compound (1C-2-1).
[0000]
[0186] FIG. 5 is a micrograph showing cells cultivated in a medium containing DMSO, NGF (20 ng/ml), and compound (1D-2-1) (1 μM). FIG. 6 is a micrograph showing cells cultivated in a medium containing DMSO, NGF (20 ng/ml), and compound (1D-2-1) (10 μM). As is clear from FIGS. 5 and 6 , under the presence of DMSO and NGF (20 ng/ml), the sample including 1 μM or 10 μM of compound (1D-2-1) resulted in further enhanced neurite outgrowth activity, compared with the sample without compound (1D-2-1).
[0187] Compound (1D-2-3) and the diastereomer mixture of compound (1C-2-5) and compound (1D-2-5) were also subjected to the activity test in a manner similar to that described above. The results show that, under the presence of DMSO and NGF (20 ng/ml), the sample including 10 μM of compound (1D-2-3) resulted in further enhanced neurite outgrowth activity, compared with the sample without compound (1D-2-3). The results also show that, under the presence of DMSO and NGF (20 ng/ml), the sample including 10 μM of the diastereomer mixture of compound (1C-2-5) and compound (1D-2-5) resulted in further enhanced neurite outgrowth activity, compared with the sample without the diastereomer mixture of compound (1C-2-5) and compound (1D-2-5).
|
The present invention provides a new bis(tetrahydrofuran) compound having an excellent neurotrophic factor activity-enhancing effect, and a process for producing the same. The bis(tetrahydrofuran) compound of the present invention is represented by formula (1):
wherein R 1 and R 2 are the same or different, and represent a C 1-4 alkyl group, a C 1-5 alkoxy group, an aryl C 1-5 alkoxy group, a C 2-5 alkenyloxy group, or an aryl C 2-5 alkenyloxy group, or R 1 and R 2 together represent ═O or ═CH 2 ; R 3 represents a hydrogen atom or a group —CH 2 —O—R 4 ; R 4 represents a C 1-4 alkyl group, a C 1-5 alkylcarbonyl group, or an aryl C 1-4 alkyl group that may have a substituent on an aryl ring; and a carbon-carbon bond between “a” and “b” represents a single bond or a double bond. The bis(tetrahydrofuran) compound has an excellent neurotrophic factor activity-enhancing effect.
| 2
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BACKGROUND OF THE INVENTION
Heretofore cutting tools of the prior art have used replaceable cutters so that when the parts became worn the old cutter would be discarded and a new cutter would be installed.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved nibbler-type cutter which overcomes the prior art disadvantages; which is simple, economical and reliable; which effectively doubles the life of the movable cutter; which is usable in a detachable nibbler slide block; and which is reversibly mounted in the nibbler slide block.
Other objects and advantages will be apparent from the following description of the invention and the novel features will be particularly pointed out hereinafter in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention is illustrated in the accompanying drawings in which:
FIG. 1 is a side elevational view, partly in section, of a portable cutting tool constructed in accordance with the present invention.
FIG. 2 is a front elevational view, taken along lines 2--2 of FIG. 1.
FIG. 3 is a partial side elevational view showing the nibbler slide block connected to the cutting tool.
FIG. 4 is an exploded perspective view of the elements of the nibbler-type cutter.
FIG. 5 is a partial front elevational view showing the nibbler slide block engaging the slide way of the cutting tool.
FIG. 6 is a dramatized view showing the stored bit unused and the engaged bit worn.
FIG. 7 is a partial side elevational view showing the nibbler bit reversed so that the unused bit is mounted for the cutting operation.
FIG. 8 is a partial front elevational view of the shear type cutter, partly in section.
FIG. 9 is a partial side elevational view of the shear type cutter, partially in section.
DESCRIPTION OF THE INVENTION
In the illustrated embodiment of the invention FIG. 1 shows a portable cutting tool of the nibbler-type, designated generally 10, having a housing 12 including a handle 14 disposed in superposition to a motor portion 16 and a head 18. An electric motor 20 is mounted within the motor portion 16 and includes a drive shaft 22 extending into the head 18 and having a splined end 24 that meshes with a gear 26 mounted on a shaft 28 journaled in the head 18 on an axis parallel to the axis of the shaft 22. An eccentric 30 illustrated in FIGS. 1 and 2 is secured for rotation with the shaft 28 and is connected through a link 32 to a bar 34 mounted for reciprocation in the head 18.
The lower end of the bar 34 as illustrated in FIG. 1 extends outwardly of the bottom of the housing 12 into a side or laterally extending opening 36 formed between a front mounting plate 38 and rear mounting plate 40, each secured to the head by screws 42. The oppositely facing side walls of the mounting plates 38 and 40 have aligned grooves 44, 44 illustrated in FIGS. 1, 3 and 5. A lock pin 46 is mounted in a counterbore 48 of the rear mounting plate 40 and bias by a spring 50 to have its tip 52 normally extended outwardly into side opening 36 from which it may be withdrawn by an operating grasping the handle 54 to pull the same in a direction away from the opening 36.
The lower end of bar 34 has a tongue and groove 56 formed thereon as is illustrated in FIGS. 1, 3, and 4. The bar 34 defines an upper bar which will connect to a lower bar 58 which has a tongue and groove 60 formed at its upper end to be slidingly received within the tongue and groove 56 of the bar 34 to form an interlocking box joint 61 therewith. Thus the bar 58 is keyed to the bar 34 and will unitarily reciprocate therewith upon operation of the motor 20.
The lower bar 58 is slidingly received within a central aperture 62 of a slide block 64 illustrated in FIGS. 1-4. The slide block 64 has a window 66 formed on the forward side thereof as viewed in FIGS. 2 and 3 to permit proper alignment of the respective tongue and groove 56 and 60 connection so as to form the box joint 61.
The slide block 64 is substantially rectangular, with the longer sides thereof facing the front and rear as viewed in FIG. 1 and having tongues 68, 68 formed thereon. When the slide block 64 is slid laterally as illustrated in FIG. 5 within the mounting plates 38 and 40 a tongue and groove connection will be made between tongue 68 and grooves 44. Of course, during the tongue and groove connection the lock pin 46 will be removed from its blocking position so that once the connection is made the tip 52 thereof will enter a locking hole 70 shown in FIG. 1. Thus assembled the slide block 64 is held against movement relative to the head 18. Whenever it is desired to remove the slide block 64 the lock pin 46 will be pulled outwardly to remove the tip 52 from the hole 70 to permit the lateral sliding disassembly movement of the slide block 64 relative to the head 18.
A tapped counterbore 72 extends upwardly from the bottom of the mounting bar 58 as shown in FIGS. 1 and 4, with a tapped hole 74 formed at the lower end of the side opposite the tongue 60 and extending through to the bore 72. A cutter 76 is threadedly received within the tapped counterbore 72 and secured therein by a set screw 78 connected within the hole 74 to engage the side wall or shank of the cutter 76.
The cutter 76 is symmetrically formed so that the side above its mid-point is the mirror-image of the side below the mid-point and therefore the cutter 76 can be mounted from either end. The cutter 76 is best seen in FIGS. 1 and 4 and has a threaded portion 80 at the upper and lower ends thereof which terminates in a cylindrical shank portion 82 with the inner ends of the opposite shanks 82, 82 terminating in a neck down portion 84 of reduced diameter which defines oppositely facing annular shoulders 86, 86 each of which define an annular cutting edge. A hypothetical mid-plane 88 would lie perpendicular to the axis 90 of the cutter 76 mid-way between the shoulders 86, 86 to dissect the neck down portion 84. The slide block 64 includes a ledger element 92 having a slot 94 formed at its lower end to receive the sheet material to be cut. The upper edge 96 of the slot 94 defines a fixed cutter adjacent the axial aperture 62 and will co-act with the lower of the cutting edges or shoulders 86 of the cutter 76 on the upstroke of the bar 34 to remove a cresent-shape section of the sheet material. The ledger element 92 is suitably secured to the slide block 64 so as to affix the annular upper sleeve 98 within the aperture 62 wherein its inner periphery will journal the reciprocatory motion of the mounting bar 58.
Subsequent to the cutter being threadedly connected to the mounting bar 58 its threaded lower end 80 will extend below the ledger element 92 to receive thereon a cutter knob 100 held in place by a nut 102 threadedly received on the end 80 as illustrated in FIGS. 1 and 4. During the lateral slide mounting of the slide block 64 to the mounting plates 38 and 40 the knob 100 will be used to align the mounting bar 58 with the bar 34 as by rotating the same so as to permit the slide motion of the interlocking connection between the respective tongue and grooves of the bars 34 and 58. Once the alignment has been obtain the slide block 64 is assembled to the head 18 thus keying the respective bars 34 and 58 for unitary reciprocal motion upon operation of the motor 20. The connection of the bars 34 and 58 is adapted to be detached upon the disassembly of the slide block 64 from the mounting plates 38 and 40.
Though the tolerances are close there is sufficient clearance to permit the reciprocal motion of the bars 34 and 58 and the cutter 76 within the journaled components thereof. After an unspecified period of time depending on the care and the nature of the sheet material being cut, the engaged moving cutting edge will eventually wear as illustrated in FIG. 6 by the worn or rounded cutting edge or shoulder 86A which has been in use during the cutting operation. A second fresh cutting edge 86B is shown in stored position immediately above the worn edge 86A and upon reversal of the cutter 76, which the operator may readily accomplish, the assembly will be as shown in FIG. 7 wherein the fresh cutting edge 86B is in position for the cutting operation wherein it will co-act with the upper cutting edge 96 of the slot 94. Through the simple device of reversing the cutter 76 the effective life of the cutter 76 has been substantially doubled.
FIGS. 8 and 9 show the head 18, the bar 34 to which a second slide block 104 is connected to the mounting plates 38 and 40 in the same tongue and groove type detachable connection. During the lateral assembly motion of the slide block 104 a connecting member 106 having a tongue and groove top portion 108 is slidingly received in the tongue and groove 56 of the bar 34. The connecting member 106 is mounted within the slide block 104 for reciprocal motion therein. The connecting member 106 has a side cutout 110 formed at its lower end to define a vertical seating surface 112 which receives a shear type cutter 114 having a cutting edge 116 and being secured thereto by a screw 118. The shear type cutter 114 cooperates with a ledger element 120 having a ledger blade 122 carried by an arm 124 suitably secured to the bottom of the slide bracket 104.
It will be understood that various changes in the details, materials, arrangements of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principles and scope of the invention.
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A portable cutting tool, and particularly a tool designed as a nibbler-shear for use in cutting sheet material. The tool includes a power head with a changeable block, one for a shear type cutter and one for a nibbler type cutter. The one with the nibbler type cutter has a fixed cutter and a movable cutter. The movable cutter is reversibly mounted and has two cutting edges, one co-acting with the fixed cutter and the other to remain in a stored position for future use.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of U.S. patent application Ser. No. 11/406,417, filed on Apr. 18, 2006, which is incorporated by reference into this application.
FIELD OF THE INVENTION
[0002] This invention relates to the field of supports and more particularly to an adjustable support device for mounting a planar object between two opposing surfaces.
BACKGROUND OF THE INVENTION
[0003] In hurricane-prone areas or possibly tornado-prone areas, often when advance notice is provided, windows and doors get covered with plywood to reduce penetration by wind and flying debris. In the past, the plywood was screwed or nailed to the door or window frame and removed when the storm resided. The process of holding the plywood in place and nailing or screwing it to the frame is time-consuming and often required one person to hold the plywood while another person fastens the plywood to the window or door frame. Unfortunately, the screws leave holes where they entered the frame. Even worse, if not pre-drilled, the nails or screws sometimes crack the frame.
[0004] An improvement to the process of mounting plywood to the door or window frame is described in U.S. Pat. No. 5,634,618 to Farmer, Jr. et al., which is hereby incorporated by reference. This patent describes an adjustable clip for mounting the plywood between two opposing surfaces (e.g., the inner side surfaces of the door or window frame). The clip described in this patent has a U-shaped “cup” portion into which the plywood fits and a means to apply force to the opposing surfaces which, in one embodiment, is a screw. Unfortunately, this clip is not suitable for a range of materials, being designed to fit only one size of material (e.g., ¼″ plywood). This requires installers to carry different clips for different sizes of plywood or similar material (e.g., ¼″ plywood, ⅜″ plywood, ½″ plywood, 10 mm plastic). Furthermore, after the storm, if plywood is used, it often absorbs moisture. The plywood swells from the moisture and may not fit in the U-shaped cup of this patent.
[0005] What is needed is an adjustable clip or support that fits many different thicknesses of planar material such as plywood while holding the planar material against the inner surfaces of a window or door frame during situations such as severe weather.
SUMMARY OF THE INVENTION
[0006] In one embodiment, an adjustable support for mounting a substantially planar object between substantially opposed support surfaces is disclosed including a substantially L-shaped base and a clamp. The clamp is removably and adjustably attached to the first side of the L-shaped base, thereby forming an aperture between the second side of the L-shaped base and the bottom surface of the clamp. The aperture is adaptable to accept various thicknesses of substantially planar objects. A device is provided for engaging the adjustable support with a support structure, passing through the clamp and passing through a hole in the first side of the L-shaped base and entering a hole in the support surface to hold the substantially planar object between the first support surface and a substantially opposed second support surface.
[0007] In another embodiment, a system for protecting an opening is disclosed; the opening has substantially opposed support surfaces. The system includes a substantially planar object sized to fit snuggly within the opening between a first and second opposing support surface. The system includes holes formed in the opposing support surfaces. A plurality of adjustable supports hold the planar object within the opening; each the adjustable supports includes a substantially L-shaped base having and a clamp. The clamp is removably and adjustably attached to a first side of the L-shaped base thereby forming an aperture between a second side of the L-shaped base and a bottom surface of the clamp. The aperture accepts and holds planar object of various widths. A locking pin passes through each clamp and through an elongated hole in the first side of the L-shaped base. The locking pin inserts into the holes in the substantially opposed support surfaces, thereby holding the substantially planar object within the opening.
[0008] In another embodiment, an adjustable support for mounting a substantially planar object between substantially opposed support surfaces is disclosed including a substantially L-shaped base and a clamp. The clamp is removably and adjustably attached to a first side of the L-shaped base forming an aperture between a second side of the L-shaped base and a bottom surface of the clamp. The aperture accepts and holds the planar object. A device for securing the adjustable support to the substantially opposed support surfaces passes through the clamp and through an elongated hole in the first side of the L-shaped base and interfaces with the substantially opposed support surfaces thereby holding the substantially planar object between the substantially opposed second support surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:
[0010] FIG. 1 illustrates a perspective view of a support of the present invention.
[0011] FIG. 2 illustrates a rear perspective view of a support of the present invention.
[0012] FIG. 3 illustrates an exploded view of a support of the present invention.
[0013] FIG. 4 illustrates a view of a door shielded by a planar sheet of material held in place by multiple supports of the present invention.
[0014] FIG. 5 illustrates an exploded view of an alternate support of the present invention.
[0015] FIG. 6 illustrates a perspective view of a support of a second embodiment of the present invention.
[0016] FIG. 7 illustrates a second perspective view of a support of the second embodiment of the present invention.
[0017] FIG. 8 illustrates a perspective view of a sleeve of the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. The support of the present invention is designed to hold in place any conceivable stiff, planar object including wood (e.g., plywood), composite material, plastic (e.g., clear polycarbonate panels or polypropylene panels), glass and metal (e.g., aluminum and galvanize steel). Furthermore, the planar material can be corrugated or accordion style. If corrugated or accordion style, the support of the present invention is preferably deployed at locations along the structural sides of the planar material such that as force is applied, it forms a wedge instead of compressing the corrugations or accordion folds. The support of the present invention holds this planar object securely between two substantially opposed support surfaces by applying traverse pressure between at least one of the support surfaces and the planar object. The support surfaces can be any substantially opposed surface including, but not limited to, two parallel sides of a door frame or window frame.
[0019] As will be seen, the adjustable supports of the present invention provide an adjustable aperture that can accept and hold a wide range of thicknesses of planar material allowing an installer to need only one type of support for installation of many types of planer material. For example, sheet steel may have a thickness of ¼″ while plywood or polycarbonate panels may have a thickness of ¾″. The supports of the present invention can be adjusted to work equally well with both thicknesses of planar material. Furthermore, often after the storm subsides, the planar material is removed from the structure being protected. If the planar material accepts moisture and expands (e.g., plywood), it is important that the supports adjust to the slightly thicker, off-tolerance planar material. This would not be easy to do with the supports of the prior art.
[0020] Referring to FIG. 1 , a perspective view of an adjustable support of the present invention is shown. An L-shaped base 22 and clamp 20 are configured to sandwich a planar sheet of material 40 (shown in FIG. 4 ) in an aperture 60 . In a preferred embodiment, base serrations 14 catch and hold clamp serrations 12 , holding the clamp against the planar sheet of material 40 until screws 24 (shown in FIG. 3 ) are inserted and tightened. The base serrations 14 are angled toward the base 22 bottom while the clamp serrations 12 are angled away from the base 22 bottom, thereby engaging with each other to hold the clamp 20 in position with respect to the base 22 while inserting and tightening screws 24 (shown in FIG. 3 ) creating an aperture 60 of desired size. The pressure screw 30 is threaded in preferably the clamp 20 or alternately the base 22 and is tightened to apply pressure against two opposing support surfaces in between which the planar sheet 40 has been inserted as will be shown in FIG. 4 . The two opposing support surfaces are, for example, the inner walls of a door frame or the inner walls of a window frame.
[0021] The L-shaped base 22 and clamp 20 are made from any sturdy material, preferably aluminum, steel, stainless steel, ultra-high molecular weight plastic (UHMW) or a structural plastic such as glass-filled polypropylene.
[0022] Referring to FIG. 2 , a rear perspective view of an adjustable support of the present invention is shown. Shown is the base 22 with elongated screw holes 26 through which clamp screws 24 (shown in FIG. 3 ) pass and another elongated screw hole 32 through which the pressure screw 30 passes. The elongated screw holes 24 / 32 allow movement of the clamp 20 with respect to the base 22 . In this embodiment, serrations 12 / 14 hold the clamp 20 in place with respect to the base 22 while tightening clamp screws 24 , thereby locking the clamp 20 in position with respect to the base 22 . The serrations also provide structural locking between the clamp 20 and the base 22 .
[0023] Referring to FIG. 3 , an exploded view of an adjustable support of the present invention is shown. Shown is the base 22 with the optional serrations 14 visible from the side only. The optional serrations 12 of the clamp 20 are visible. The pressure screw 30 threads through threads 34 in the clamp 20 and passes through an elongated hole 32 in the base 22 , thereby permitting the clamp 20 to move closer to the base 22 to tightly hold the planar material 40 (not shown). Likewise, clamp screws 24 pass through the elongated holes 26 in the base and into threaded holes 28 in the clamp. The clamp screws 24 hold the clamp 20 and base 22 in relative position after they are adjusted to the desired aperture size.
[0024] Referring to FIG. 4 , a view of a door shielded by a planar sheet of material held in place by multiple adjustable supports of the present invention is shown. The door is by example. Any opening can be protected with the present invention including, but not limited to, a door and a window. The door has a frame with decorative molding 44 . In this example, a sheet of plywood is fitted within the inside edges of the door frame 47 / 48 and a plurality of supports 10 of the present invention are situated holding the plywood 40 between the clamp 20 and base 22 of the supports 10 and the supports 10 apply pressure to the opposing inside edges of the door frame 47 / 48 by tightening the pressure screws 30 of each support 10 . As shown, supports are positioned on opposite edges of the planar material 40 , which can be any relatively flat and stiff material such as plywood, etc. It is preferred to place the supports 10 at 6 inches from the edge of the planar material 40 and at every 12 inches thereafter. For added strength, supports 10 can be placed on the top and bottom edges of the planar material 40 , thereby exerting pressure on the top and bottom inside walls 48 of the frame 42 . In another embodiment, supports 10 are placed along only one edge of the planar material 40 . For additional protection, the pressure screw 30 can have a protective cup on its end where it interfaces with the door frame 47 / 48 or a thin sheet of a stiff material such as steel can be placed between the end of the pressure screw 30 and the opposed surfaces.
[0025] Referring to FIG. 5 , an exploded view of an alternate support of the present invention is shown. Shown is the base 22 with a relatively smooth surface 64 (without serrations) visible from the side only. The face 62 of the clamp 20 is also relatively smooth. Being that the base 22 and the face 62 of the clamp 20 are relatively smooth, friction between these two surfaces holds them in place with respect to each other. In some embodiments (not shown) these surfaces 62 / 64 can be textured or alternately, a gasket can be placed between them to hold the base 22 in place with respect to the clamp 20 . The pressure screw 30 threads through threads 34 in the clamp 20 and passes through an elongated hole 32 in the base 22 , thereby permitting the clamp 20 to move closer to the base 22 to tightly hold the planar material 40 (not shown). Likewise, clamp screws 24 pass through the elongated holes 26 in the base and into threaded holes 28 in the clamp. The clamp screws 24 hold the clamp 20 and base 22 in relative position after they are adjusted to the desired aperture size.
[0026] Referring to FIG. 6 , a perspective view of an adjustable support 110 of a second embodiment of the present invention is shown. An L-shaped base 122 and clamp 120 are configured to sandwich a planar sheet of material 40 (shown in FIG. 4 ) in an aperture 160 . The base serrations 114 are angled toward the base 122 bottom while the clamp serrations 112 are angled away from the base 122 bottom, thereby engaging with each other to hold the clamp 120 in position with respect to the base 122 while inserting and tightening screws (as shown in FIG. 3 ) creating an aperture 160 of desired size. The locking pin 131 and locking pin handle 130 are shown in position of being engaged with the opposing support surfaces 47 / 48 . To release the clip from the opposing support surfaces 47 / 48 , the locking pin handle 130 is rotated 90 degrees past a detent 133 to a point where it clears the locking pin retainer 135 , at which point it can be easily pulled to disengage from the hole in the opposing support surfaces 47 / 48 . This locking mechanism is easier to operate during installation and removal since the locking mechanism of the prior embodiments require a screw driver held against the planar material 40 to turn the locking screw 30 .
[0027] In some embodiments, a boss 126 is provided in the L-shaped base 122 and an elongated hole 127 in the clamp 120 to secure the clamp 120 to the L-shaped base 122 with screws (not shown).
[0028] In this embodiment of the present invention, holes are made in the opposing support surfaces 47 / 48 to accept the locking pin 131 .
[0029] Referring to FIG. 8 , a perspective view of a sleeve of the second embodiment of the present invention is shown. In some embodiments, a sleeve 170 is inserted into the holes in the opposing support surfaces for ascetic reasons and to reduce friction when inserting and removing the locking pin 131 . In some embodiments, a cap 172 is provided to cover the open end of the sleeve 172 and in some embodiments the cap 172 is tethered to the sleeve 170 (tether not shown) and covers the holes when not in use for ascetic reasons and to keep debris out of the sleeve.
[0030] During installation, the locking pin handle 130 is positioned to an approximately 90 degree angle from the clamp 120 , thereby clearing the locking pin retainer 135 . Once the locking pin 131 is aligned with the hole in the opposing support surfaces, the locking pin 131 is pushed into the hole. To keep the locking pin 131 in place, the locking pin handle 130 is rotated approximately 90 degrees, passing a detent 133 that holds it against the clamp 120 .
[0031] In some embodiments, a security screw 121 is used to keep the planar material from pulling out of the adjustable support 110 during high winds. The security screw 121 passes through the clamp 120 , through a hole cut in the planar material 40 and through a hole in the L-shaped base 122 , where it is held in place by a nut 123 (not visible in FIG. 6 ).
[0032] The L-shaped base 122 and clamp 120 are made from any sturdy material, preferably aluminum, steel, stainless steel, ultra-high molecular weight plastic (UHMW) or a structural plastic such as glass-filled polypropylene.
[0033] Referring to FIG. 7 , a second perspective view of an adjustable support 110 of a second embodiment of the present invention is shown. An L-shaped base 122 and clamp 120 are configured to sandwich a planar sheet of material 40 (shown in FIG. 4 ) in an aperture 160 . The base serrations 114 are angled toward the base 122 bottom while the clamp serrations 112 are angled away from the base 122 bottom, thereby engaging with each other to hold the clamp 120 in position with respect to the base 122 while inserting and tightening screws (as shown in FIG. 3 ) creating an aperture 160 of desired size. The locking pin 131 and locking pin handle 130 are shown in position of being engaged with the opposing support surfaces 47 / 48 . To release the clip from the opposing support surfaces 47 / 48 , the locking pin handle 130 is rotated 90 degrees to a point where it clears the locking pin retainer 135 , at which point it can be easily pulled to disengage from the hole in the opposing support surfaces 47 / 48 . This locking mechanism is easier to operate during installation and removal since the locking mechanism of the prior embodiments require a screw driver held against the planar material 40 to turn the locking screw 30 . Once all adjustable supports 110 are disengaged, the planar material 40 is easily removed from the opposing support surfaces 47 / 48 .
[0034] In this embodiment of the present invention, holes are made in the opposing support surfaces 47 / 48 to accept the locking pin 131 . In some embodiments, a sleeve 170 (see FIG. 7 ) is inserted into the holes for ascetic reasons. In some embodiments, a cap 172 is provided to cover the holes in the opposing support surfaces when not in use for ascetic reasons and to keep debris out of the sleeve.
[0035] During installation, the locking pin handle 130 is positioned to an approximately 90 degree angle from the clamp 120 , thereby clearing the locking pin retainer 135 . Once the locking pin 131 is aligned with the hole in the opposing support surfaces, the locking pin 131 is pushed into the hole. To keep the locking pin 131 in place, the locking pin handle 130 is rotated approximately 90 degrees, passing a detent 133 that holds it against the clamp 120 .
[0036] In some embodiments, a security screw 121 is used to keep the planar material from pulling out of the adjustable support 110 during high winds. The security screw 121 passes through the clamp 120 , through a hole cut in the planar material 40 (shown in FIG. 4 ) and through a hole in the L-shaped base 122 , where it is held in place by a nut 123 .
[0037] The L-shaped base 122 and clamp 120 are made from any sturdy material, preferably aluminum, steel, stainless steel, ultra-high molecular weight plastic (UHMW) or a structural plastic such as glass-filled polypropylene.
[0038] Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.
[0039] It is believed that the system and method of the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.
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The present invention is an adjustable support for installing a planar sheet of material between opposed surfaces for protection from events such as storms. The supports secure the planar sheet to an opening such as a door and window, thereby holding it in place during storms, etc. The supports are easily removed and include a substantially L-shaped base and a clamp. The clamp is removably and adjustably attached to the first side of the L-shaped base, thereby forming an aperture between the second side of the L-shaped base and the bottom surface of the clamp. The aperture is adaptable to accept various thicknesses of substantially planar objects. A device is provided for engaging the adjustable support with a support structure, passing through the clamp and passing through a hole in the first side of the L-shaped base and interfacing with support surfaces to hold the substantially planar object between the first support surface and a substantially opposed second support surface.
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This invention relates to foldable sunshields for automobile and vehicle windows, including, particularly, the windshield, and the method of manufacture of such sunshields.
BACKGROUND OF THE INVENTION
Prior art sunshields for covering the interior sides of the windshields of automobiles, particularly those made in accordance with Levy, U.S. Pat. No. 4,202,396, have enjoyed a rather remarkable success. Sunshields made in accordance with Levy are comprised of about 10 elongated, rectangular panels, each slightly over 5 inches wide and approximately 201/4 inches long. The successive panels in Levy are folded in alternate directions, that is, the panels are folded accordion-like. Various other sunshields have also proved to be readily accepted in the automobile sunshield market, such as those covered by Zheng U.S. Pat. No. 4,815,784. Kim, U.S. Pat. No. 5,267,599, shows parallel creases, or channels, alternately located on opposing sides of a foam material, so that it can be alternately folded in opposite directions from the crease. Kim shows a sunshield comprised of 4 rectangular panels and a sunshield comprised of 5 rectangular panels. Niernberger, U.S. Pat. No. 4,848,825 teaches a trapezoidal panel on each end of an automobile windshield cover which is used on the outside of an automobile windshield.
SUMMARY OF THE INVENTION
This invention is an improved, foldable sunshield of semi-rigid, "impressionable material". By "impressionable material" is meant material that can be impressed with a crease, or which can be manufactured with such a crease or channel and which will retain all or part of such crease or channel enabling the material to readily be folded thereafter along the crease. A "channel" is considered to include within its meaning, a "crease". Crease, by definition, includes, without limitation, folding. That is, a "crease" is a particular manner of creating a "channel". So, "channel" is defined herein as broader and inclusive of "crease". A "channel" may be formed in the material as it is manufactured or in other ways, and, thus, might not be formed by creasing. For some materials, it may be required that the material or the creasing die or block be heated in order to suitably impress the material. The creases or channels which are then in the sunshield material allow the sunshield to be easily folded and put away and, later, unfolded and thus used many times.
The sunshield is preferably fitted to and used on the interior side of the windshield of a vehicle or an automobile, however, it may be used on the outside of an automobile window as shown in U.S. Pat. No. 4,848,825, or it may be used on the inside or outside of the rear window or any other window of a vehicle or an automobile. However, it is adapted best to be used on the interior side of the windshield of an automobile. It is so adapted by fitting it, in its unfolded condition, to the size and shape of such interior side of the windshield of an automobile. It is constructed best to fit under the visors when they are down and to fit around the rear view mirror or to have a cutout through which the mirror and the strut which holds it, can extend.
The sunshield is formed of a core material which is impressionable. Among the various impressionable materials are foam material, foam-like material, cellular material, cardboard, particularly the corrugated kind, and various bubble plastics and crinkle plastics. Numerous polymers are manufactured in the form of a foam. Usually this is accomplished by mixing the polymer, or plastic, with a blowing agent which is a gas that is often nitrogen. This forms a cellular material. Both thermoplastic and thermoset polymers are converted into foams in this and other ways. Sometimes, the cellular material will have a rigid, smooth skin and a cellular core. Polystyrene foam, (styrofoam), and polyurethane foam are examples of commonly-available foams made from polymers. Such foams may be adhered to, formed around or formed integral with fibers, filaments, threads, netting, screen or woven materials such as a fabric whether of plastic or of cotton, wool or other textile material. A polyester may be found very useful as the core material of the sunshield if the polyester is reinforced with fibers, filaments, threads, netting, screen or woven materials.
One method of forming bubble plastics, explained in U.S. Pat. No. 4,535,828, issued Aug. 20, 1985, embosses two films of polyethylene, creating peaks and valleys and adheres the films together at the peaks, which causes the valleys to form closed cell bubbles. That patent discloses the use of a slitted laminate of metallized polyethylene in a folding window shade used in a building.
Corrugated material, honeycomb material and other expanded materials may be found suitable for use as the sunshield material herein, particularly if they are heat-insulative in character.
Foam material, cellular material and bubble plastics are particularly advantageous as the core material of the impressionable material or as one or more of the layers in the sunshield because they provide insulation against heat transfer through the sunshield.
Other impressionable materials may be found to be suitable. For example, certain insulative plastics, whether of single layer or multiple layers of the same or differing materials, which are not made into foam, may be found quite suitable in practicing this invention.
The impressionable materials may be reflective in themselves or it may be desirable to add a reflective coat. Aluminum paint, nickel paint or silver paint and other metallic paints and combinations thereof on a plastic film are customarily used to provide reflective coatings. The sunshield material may be comprised of multilayers and one or more of the layers may be a reflective layer. The reflective layer may be comprised of a reflective metallic paint deposited on a polymer, such as Mylar, polyethylene, vinyl, polyvinyl chloride, acrylate, or any number of other suitable plastic films. Paper or other material may also be used. Such reflective layer preferably has an outer, protective layer of a transparent film placed over it, although it may be found that the reflective coating could be placed on the inside of an outer, protective film which would thus serve a dual purpose. U.S. Pat. No. 4,261,649, Reflective Sun Screen, teaches the use of an acrylic outer coating over a layer of reflective Mylar, a polyester. As set forth in that patent, other reflective polyester films are also available for use in providing a reflective coating. A durable, metallic coating could be placed on the outside of the outer film of the sunshield material.
Polyethylene and other films may be used. Of course, numerous thermoplastic and thermosetting films may be found suitable as outer coatings or to be used as films having reflective coatings. The core material could itself be metallized to provide the reflective layer.
The sunshield material may be a single layer of material or it may be comprised of a plurality of layers of the same or of differing materials. In the patent to Kim, cited above, is disclosed the step of heating the outer surfaces of a film such as polyethylene and creating pockets of air, crinkles, in the outer layers, or films, which may or may not be reflective.
By using a semi-rigid or even a rigid material, the sun-shield does not collapse and stays in place, held, for example, by the sun visors of an automobile, the rear view mirror or by other means. Brackets, clips, Velcro, hooks, straps, pins, adhesive or other means may be used to hold the semi-rigid or rigid sunshield in place. The sunshield itself may have suction cups, straps, Velcro, elastic bands and other appurtenances which aid in the use or storage of the sunshield.
The method herein enables quicker and more convenient manufacture of vehicle sunshields. The resulting product is more economical to produce, yet results in a quality product.
In the preferred embodiment of this invention, the sunshield is manufactured from an impressionable material by placing a plurality of creases therein for folding the sunshield. All of the creases are on the same side of the material and alternate creases are slightly wider to allow the material to fold easily over the crease, in the alternate direction. U.S. Pat. No. 4,317,481, to Oswald, utilizes double wide spaces in a thermal barrier comprised of slats placed adjacent each other, but does not teach or suggest any such structure which is accomplished by channels or creases in an impressionable material. In the invention herein, the wider creases allow the material to fold over the side the wider creases are created on. Where the material has a narrow, or smaller, crease, the material is folded away from side the crease lies on. Such narrow creases combined with wider creases allow the sunshield to be folded accordion-like, in alternate directions, folding one direction at a narrow crease and folding the other direction at a wide crease.
It is to be realized that all such creases may be made slightly wider and the sunshield could still be properly folded in alternate directions. Such creases may be parallel or only approximately parallel to each other thus forming planar elements which are rectangles or, possibly, only approximately rectangles. On the other hand, such creases may be at an angle with respect to each other thus forming planar elements which are not rectangles but are approximately trapezoids. If the top and bottom of the sunshield are parallel, the planar elements are trapezoids. If they are not parallel, the planar elements are approximate trapezoids.
It can be seen that the creases form hinge-like connections between adjoining planar elements. More than one crease may be used between adjacent elements. That is, there may be two creases, side by side, two creases which overlap or two creases a small distance apart in order to create, in effect, a wider crease.
Folding of a sunshield in alternate directions, which is accordion-like, is taught in Levy but Levy makes no suggestion of wider creases nor of placing all creases nor placing of all channels on the same side of the sunshield material.
Although the preferred embodiment of this invention has all of the creases on the same side of the sunshield material, another embodiment might have some creases on the opposite side, but this invention does not have the creases located alternately on opposite sides of the material, as in Kim, mentioned above.
If it is considered that the sunshield material has two opposing sides, in back-to-back relationship, it may be seen that the creases or channels of this invention are all located on one of the sides. There are no creases or channels, used for accordion-like folding, in the other side of the sunshield material. Of course, there may be creases or channels irrelevant to the accordion-like folding, in such other side, but there are no creases in the other side about which the sunshield material is folded in the accordion-like folding of the sunshield.
The creases or channels may be v-shaped, u-shaped having a round bottom, or channel-shaped having a substantially flat bottom. The same kind of crease or the same kind of a channel may be used throughout a sunshield or they may be varied in a single sunshield, as desired. Such creases may be cold-formed or heat-formed as desired and depending on the material or materials being used. The creases or channels may be formed, during the process of manufacturing the material, by extrusion or other process. Preferably, the material is comprised of a thermoplastic foam or a thermoplastic bubble pack and creases are formed using heat-forming of creases after the material is manufactured.
Creases are preferably formed by a creasing tool or shoe, but, less preferable creases may be formed by a slitting mechanism as set forth in U.S. Pat. No. 4,535,828.
If a protective film or a reflective film are added to the core material, the creasing may be done before the film or films are added or after the film or films are added, depending on the nature and thickness of the added film or films. If a thick, hardy film is to be added to the core material, the creasing would likely be done after the film is added to the core material. On the other hand, a thin or very flexible film could be added to a core material after the core material is creased.
This invention comprises both a foldable sunshield product and a method of manufacture of the foldable sunshield product from an impressionable material without having to crease the material alternately on opposing sides as taught by Kim, cited above.
Consequently, this invention removes the requirement to turn the material over in order to place creases on the alternate side or to have additional jigs and fixtures which will crease the material simultaneously from both sides. In mass production, creasing the material on a single side constitutes a substantial and important time-saving and cost-saving feature.
Therefore, an object of this invention is to provide a sunshield manufactured from impressionable material which folds in alternate directions along a successive plurality of creases on the same side of the impressionable material.
Another object of this invention is to provide a sunshield manufactured from impressionable material which has alternate creases of wide and narrow widths.
It is another object of this invention to provide a sunshield of impressionable material which folds accordion-like along creases, all of which creases are on the same side of the impressionable material.
It is, therefore, an object of this invention to provide a method of manufacture of a foldable sunshield which is economical and convenient.
Still another object of this invention is to provide a method of manufacture of a foldable sunshield which creases the sunshield material on a single side.
Further objects and features may be seen from the following figures and description. It is to be understood that the drawings are designed for illustrative purposes and are not intended to define the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a prior art sunshield.
FIG. 2 is a sunshield of the invention creased in accordance with the preferred embodiment of the invention.
FIG. 3 is an end view of the unfolded sunshield of FIG. 2, viewed from line 3--3, FIG. 2, showing creases in the sunshield as being v-shaped, alternating with wider, channel-shaped creases and all on the same side of the sunshield material.
FIG. 4 is an end view, similar to FIG. 3, of an unfolded sunshield, showing creases in the sunshield as being u-shaped with rounded bottoms and all on the same side of the sunshield material.
FIG. 5 is a similar end view of an unfolded sunshield, showing creases in the sunshield as being channel-shaped, having a flat bottom and all on the same side of the material.
FIG. 6 is a similar end view of an unfolded sunshield, showing creases as all being v-shaped and on all on the same side of the material.
FIG. 7 is a cross-section of sunshield material showing a single layer film on one side of the core material of the sunshield and a possible single layer film, in dotted lines, on the other side.
FIG. 8 is a cross-section of sunshield material showing two layers of film on each side of the core material of the sunshield.
FIG. 9 is a cross-section of sunshield material showing one layer on each side of the sunshield material, each layer serving as both reflective coating and protective covering.
FIG. 10 is a cross section of sunshield material having two layers of film on each side of the core material and showing, in dotted lines, how a creasing block compresses the core material into a hinge-like connection between planar elements of the sunshield.
FIG. 11 is a cross section of sunshield material having two layers of film on each side of the core material and showing, in dotted lines, how a wide creasing block compresses the core material into a hinge-like structure between planar elements of the sunshield, so that adjacent planar elements can be folded over the wide crease.
FIG. 12 is an end view of a folded sunshield made in accordance with the invention, showing the folds at each side of the folded sunshield resulting from all creases being on the same side of the sunshield material, as shown, for example, in the end view of an unfolded sunshield in FIG. 3.
FIG. 13 is an end view of a folded sunshield made in accordance with one embodiment of the invention, showing the folds at each side of the folded sunshields resulting from two v-shaped creases on alternate sides of the sunshield material, followed by one wider crease on the same side as the second of said creases.
FIG. 13A is an end view of the unfolded sunshield of FIG. 13, showing the disposition of the wide and narrow creases.
FIG. 14 is an end view of an unfolded sunshield, showing a variation in creases, in an embodiment which requires only two wider creases.
FIG. 15 is an end view of an unfold sunshield, showing another variation in disposition of creases.
DESCRIPTION
FIG. 1 is a prior art sunshield having planar, rectangular elements in accordance with the Levy patent cited above and commonly made out of corrugated cardboard.
FIG. 2 is a sunshield 1 of the invention of a shape fitted to the windshield of an automobile. Creases 2, 3 and 4 are representative of narrow creases in the sunshield material. Creases 5, 6 and 7 are representative of the wider creases in the sunshield material. It may be seen that the creases form a hinge-like structure between planar elements 8 and 15 and the other planar elements, or panels, of the sunshield 1. Dotted line 9 indicates that a removable portion 10 might be included in the sunshield so that the sunshield could easily be installed past the rearview mirror. A suitable score line at dotted line 9 and around the rest of portion 10 would allow portion 10 to be removed. Such portion 10 could also be a bendable portion, to move it out of the way so the rearview mirror could extend through the space occupied by portion 10.
The creases shown in FIG. 2 may be made by moving the material under creasing dies or rollers or by moving the dies or rollers over the material. The creases might also be formed by a long, stamping die or dies which make one or more complete creases at a time. A firm, underlying base is provided underneath the sunshield material in order to cause the material to crease properly.
FIG. 3 is an end view of the unfolded sunshield 1 of FIG. 2, viewed from line 3--3, FIG. 2, showing creases 2, 3 and 4 in the sunshield as being v-shaped, alternating with wider, channel-shaped creases 5, 6 and 7 and all on the same side of the sunshield material 11.
FIG. 4 is an end view, taken on a line similar to FIG. 3, of an unfolded sunshield 1, showing exemplary narrow, wide, narrow creases 12, 13 and 14, respectively, in the sunshield as being u-shaped with rounded bottoms, rather than v-shaped as in FIG. 3. It is noted that all of the creases in FIG. 4 are on the same side of the sunshield material 11.
FIG. 5 is a similar end view of an unfolded sunshield 1, showing exemplary creases 16, 17 and 18, in the sunshield material 11, as being channel-shaped, having a flat bottom and all on the same side of the material. Such narrow and wide creases could be made, for example, by rollers 19 and 20 which are narrow and wide, respectively. In this embodiment, the material is moved under a number of such rollers, to cause the material to be creased at the proper locations. If, for example, the sunshield material is a thermoplastic, heated rollers or dies could be used to form a more lasting crease more readily in the thermoplastic. A simple upturned piece of wood or metal that is heated could serve as a suitable die to form such creases, by moving either the die or the material. As stated previously, long, stamping dies, could be used to create one or more entire creases at a time. Such dies may be heated if the material is thermoplastic.
FIG. 6 is a similar end view of an unfold ed sunshield 1, showing the creases as all being v-shaped and on all on the same side of the material 11. Narrow v-shaped creases 21, 22, and 23 alternate with wider v-shaped creases 24, 25 and 26.
FIG. 7 is a cross-section of sunshield material 11 showing a single layer film 28 on one side of a sunshield core material 29 which is shown, in this instance, as being a foam. A single layer film 30 may also be included on the other side of the material core material 29, as shown in dotted lines. Film 28 may be a durable, protective, film, say, a Mylar film, a polyester, for the core 29 of foam. Alternatively, film 28 could be a film of an other polyester, an acrylic, a polyvinylchloride, a polyethylene or other suitable exterior film coating. Ultra-violet blockers, colorants or dyes may be included in the film 28 to prevent deterioration of the sunshield by sunlight over a long period of time.
The film 28 may have a reflective coating on the inside surface 28A or the outside surface 28B of the film 28. It may, itself, comprise a lamination of films. Metallization of films and laminations of film layers is well-known in the window film trade, as is the use of adhesives, ultraviolet blockers, dyes and colorants. If the core material 29 has a reflective surface, the film 28 may be merely a durable, protective film. Alternately, film surface 28A may be an opaque backing which does not let light pass through. Film 28 may have holes therein or may be comprised, itself, of bubbles or foam, depending on the purpose intended to be served. Preferably, it is both a protective coating and has a reflecting surface. It may also add to the heat-insulating quality of the sunshield material.
FIG. 8 is a cross-section of sunshield material 32 showing two layers of film 33 and 34 on one side of core material 35 and two layers of film 36 and 37 on the other side of core material 35. In this embodiment, film layers 33 and 36, which are the outside layers, are protective layers and, thus, are preferably tougher and more durable than the inner films. There may be a reflective coating or a reflective layer, for example, between films 33 and 34 or, for example, between film 34 and core material 35. Such reflective layer might be, for example silver, aluminum or nickel which is painted, sprayed, evaporated or otherwise deposited onto any of the desired surfaces. Alter-natively, there may be a separate layer of a reflective material, metal or otherwise.
FIG. 9 is a cross-section of sunshield material 40 showing a film 41 on the top of core material 42 and a film 43 on the bottom of core material 42. Such film 41 is made of material which is itself reflective. The film 43, on the bottom of core material 42 may be also made reflective to provide a uniform product, or a product that can be reversed and used with either side facing toward the sun. Films 41 and 43 serve as both reflective films and protective films.
FIG. 10 is a cross section of sunshield material 45 having two layers of film 46 and 47 on the top on one side of the core material 48 and two layers of film 49 and 50 on the other side of core material 48. In FIG. 10, core material 48 is not shown as being comprised of a foam. Core material 48 may be a foam, or may not be a foam but may be composed of other impressionable material. Die 51, shown as a stamping die, in dotted lines, would cause the material to be creased as shown by dotted lines 52 and 53. Die 51 may be long, creating an entire crease at a time, or it may be designed as a block which moves across the material or past which the material moves, to create an entire crease. The underlying structure 54 provides support to allow the creasing to be properly accomplished. If the sunshield material is thermoplastic, either creasing die 51 or underlying structure 54 may be heated, or both may be heated. It may be seen from FIG. 10 how the creasing die 51 compresses the core material 45 into a hinge-like connection between planar elements of the sunshield. Creasing die 51, as shown in FIG. 10, is of insufficient width to cause a crease over which the material may be folded. The creases formed by die 51, shown in FIG. 10, would only allow the material 45 to be folded away from the crease. Creasing die 51 would have to be about 21/2 to 31/2 times as wide as that shown, in order to crease material 48 suitably so that it could be folded over the crease.
FIG. 11 is a cross section of sunshield material 45 having two layers of film 46 and 47 on the top of core material 48 and two layers of film 49 and 50 on the bottom of core material 48. Creasing die 55 is much wider than creasing die 51, of FIG. 10. FIG. 11 shows, by dotted creasing lines 56 and 57, how a wide creasing die 55 compresses the core material so that the material 45 can be folded over the crease. That is, the creasing die 55 creates a crease that is a wide, hinge-like connection between planar elements of the sunshield, so that adjacent planar elements can be folded over the wide crease. As in FIG. 10, underlying structure 52 provides a backing against which the crease is made. Either or both of the creasing die 55 and the underlying structure 52 may be heated to assist in the creasing process.
FIG. 12 is an end view of a folded sunshield 1 made in accordance with one embodiment of the invention, shown in an end view in FIG. 3. The view is taken when the sunshield 1 is folded, on the view line 3--3, FIG. 2, showing the folds at the left side 61 of sunshield 1 and the folds at the right side 62 of the folded sunshield 1. In this embodiment, all creases are on the same side of the sunshield material, as shown in the end view of the unfolded sunshield 1 in FIG. 3. Creases 2, 3, 5 and 6 may be compared with those shown in FIG. 3 to see that all creases are on the same side of the material and alternate creases 5, 6 and 7 are wide enough for the sunshield material to be folded over the crease. FIG. 12, if unfolded by unfolding the bottom panel 11A first, downwardly and to the left, correlates the creases in sunshield 1 of FIG. 10 with the creases of sunshield 1 of FIG. 3.
FIG. 13 is a similar end view of a folded sunshield 64 made in accordance with one embodiment of the invention, showing the folds at each side of the folded sunshields resulting from a wide crease 65 followed by two v-shaped creases 66 and 67 on alternate sides of the sunshield material, followed by one wide crease 68 on the same side as crease 67. This may be understood better by reference to FIG. 13A.
FIG. 13A is an end view of the sunshield 64 of FIG. 13, when unfolded, with the bottom panel 11A unfolded first, downwardly and to the left. Wide crease 65, on the bottom of the material 11, is followed by alternating creases 66 and 67 which are, in turn, followed by wide crease 68 on the same side as crease 67. The pattern of creases is continued, a wide crease followed by alternating narrow creases.
FIG. 14 is an end view of an unfolded sunshield 69, showing a variation in creases, in an embodiment which requires only two wider creases. Narrow crease 70 is followed by narrow crease 71 on the alternate side of material 11, followed by wide crease 72 on the same side as narrow crease 71. Then follows three narrow alternating crease 73, 74 and 75, followed, in turn, by a wide crease 76 and narrow creases 77 and 78 which are on opposite sides from each other.
FIG. 15 is an end view of an unfolded sunshield 79, showing another variation in disposition of creases. Alternating narrow creases 80 and 81 are followed by wide crease 82, followed by narrow crease 83, wide crease 84, narrow crease 85, wide crease 86, narrow crease 87 and narrow crease 88 on the alternate side of material 11. It is noted that, in this embodiment, all creases are on the same side of material 11 except the two end creases 80 and 88, which are on the opposite side from all other creases.
Although specific embodiments and certain structural arrangements have been illustrated and described herein, it will be clear to those skilled in the art that various other modifications and embodiments may be made incorporating the spirit and scope of the underlying inventive concepts and that the same are not limited to the particular forms herein shown and described except insofar as determined by the scope of the appended claims.
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A vehicle sunshield which is foldable in an accordion-like manner and method of making a foldable sunshield comprising an impressionable material having a plurality of successive creases or channels on the same side of the material. Alternate creases are wider to allow folding the sunshield over the alternate creases.
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[0001] The present application is a continuation-in-part of U.S. Ser. No. 08/827,194, now U.S. Pat. No. ______ .
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of preventing retinal ganglion cell death, associated with glaucoma, by administering to retinal ganglion cells of a mammal, a compound which blocks the putative non-inactivating sodium ion channels of the above cell type.
[0004] 2. Brief Description of the Art
[0005] Glaucoma is an optic neuropathy associated with elevated itraocular pressures which are too high for normal function of the eye, and results in irreversible loss of visual function. (See for example, Dreyer et al “Elevated glutamate levels in the vitreous body of human and monkeys with glaucoma”, Arch. Ophthalmology 114:299-305, 1996) It is estimated in medical science that glaucoma afflicts approximately 2 percent of the population over the age of forty years, and is therefore a serious health problem. Ocular hypertension, i.e. the condition of elevated intraocular pressure, which has not yet caused irreversible damage, is believed to represent the earliest phase of glaucoma. Many therapeutic agents have been devised and discovered in the prior art for the treatment or amelioration of glaucoma end co the condition or increased intraocular pressure which precedes glaucoma.
[0006] Primary open angle glaucoma (POAG) is associated with a rise in intraocular pressure (IOP). This increase in IOP is believed to contribute to the loss of optic nerve function which ultimately leads to blindness. Reduction of IOP is therefore a crucial component in the management of POAG. However, in many individuals lowering of IOP is not sufficient or ineffective in preventing vision loss associated with POAG.
[0007] It is thought that a novel class of sodium channels residing within the optic nerve of the rat are responsible for damage to the rat optic nerve following anoxia or hypoxia. However, in glaucoma the sequence of pathological events leading to the loss of optic nerve function, is not known.
[0008] The drugs currently utilized in the treatment of glaucoma include miotics (e.g., pilocarpine, carbachol, and acetylcholinesterase inhibitors), sympathomimetrics (e.g., epinephrine and dipivalylepinephrire), beta-blockers (e.g., betaxolol, levobunolol and timolol), alpha-2 agonists (e.g., para-amino clonidine) and carbonic anhydrase inhibitors (e.g., acetazolamide, methazolamide and ethoxzolamide). Miotics and sympathomimetics are believed to lower intraocular pressure by increasing the outflow of aqueous hi,or, while beta-blockers, alpha-2 agonists and carbonic anhydrase inhibitors are believed to lower intraocular pressure by decreasing the formation o: aqueous humor. All five types of drugs have potential side effects. Miotics, such as pilocarpine, can cause blurring of vision and other visual side effects which may either decrease patient compliance or require termination of miotic drug therapy. Carbonic anhydrase inhibitors can also cause serious side effects which affect patient compliance and/or necessitate withdrawal of the drug therapy. At least one beta-blocker, timolol, has increasingly become associated with serious pulmonary side effects attributable to its effect on beta-2 receptors in pulmonary tissue.
[0009] As a result additional antiglaucoma drugs are being developed, e.g., prostaglandin derivatives, muscarinic antagonists, etc. However, none of the above drugs are designed to directly interact with the retinal ganglion cell and its associated axon.
[0010] Thus, it would be desirable to prevent the loss of ganglion cell body and axon function, which may be associated with glaucoma by a biological mechanism which does not modulate aqueous humor dynamics and therefore intraocular pressure. Moreover, it would be desirable to treat the retinal ganglion cell body and axon of a mammal directly to prevent the destruction thereof by the glaucomatous condition.
SUMMARY OF THE INVENTION
[0011] Surprisingly, it has been discovered in accordance with the present invention, that sodium channel blockers which block the non-inactivating sodium ion channel of the optic nerve of a mammal may be effective for preventing the loss of retinal ganglion cells when such sodium channel blockers are administered and applied in a pharmaceutical composition. Accordingly, the present invention relates to a method of preventing loss of retinal ganglion cells and their associated axons (optic nerve) function, associated with glaucoma, by systemically or directly administering to the eye of a mammal an ophthalmic composition which includes an amount of a sodium channel blocker which is effective to block the non-inactivating sodium ion channel or the ganglion cells of said mammal.
[0012] More specifically, the present invention is directed to a method for altering a possible sequence of pathological events in retinal ganglion cells that may be associated with glaucomatous optic neuropathy. The sequence includes the pathological depolarization of retinal ganglion cells, an influx of millimolar amounts of sodium via non-inactivating sodium channels and a subsequent reversal of the sodium/calcium exchanger. Reversal of the sodium/calcium exchanger mediated by both membrane depolarization and increased intracellular sodium causes a toxic buildup of intracellular calcium. The method for altering this sequence includes a step of blocking associated non-inactivating sodium channels in retinal ganglion cells in order to prevent reversal of sodium/calcium ion exchange and subsequent buildup of the calcium ion concentration in the retinal ganglion cells to a lethal level.
[0013] Specifically, this blocking is achieved by administering to the retinal ganglion cells a pharmaceutical composition having an active ingredient with non-inactivating sodium channel blocking activity.
[0014] Specific examples of sodium channel blockers which are used as the active effective ingredients in the ophthalmic compositions of the present invention are described as benzothialzole, phenyl benzothialzole, disopyramide, propafenone, flecainide, lorcainide, aprindine, encainide, GEA-968, azure A, pancuronium, N-methylstrychnine, CNS 1237, BW1003C87, BW619C89, U54494A, PD85639, ralitoline, C1953, lifarizine, zonisamide and riluzole.
[0015] The composition may comprise an ophthalmic solution adapted for administration to the eye of a mammal in the form of intracameral injection.
[0016] A direct effect on retinal ganglion cells is an important discovery in accordance with the method of the present invention. However, normal electrical excitability of ganglion cells, crucial for vision, will not be compromised.
[0017] Further, a pharmaceutical composition provided in accordance with the present invention useful for preventing retinal ganglion cell death associated with glaucoma with the composition comprising with its active ingredient one or more compounds having non-inactivating sodium channel blocking activity.
[0018] More specifically, the present invention provides a method for preventing retinal ganglion cell death associated with glaucoma in an animal of the mammalian species, including humans, which includes the step of administering to the retinal ganglion cells of the mammal a pharmaceutical composition which comprises as its active ingredient one or more compounds having non-inactivating sodium channel blocking activity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The advantages and features of the present invention would be better understood by the following description when considered in conjunction with the accompanying drawings.
[0020] [0020]FIG. 1 is a diagram of the assumed relevant transport mechanisms for a retinal ganglion cell under normal conditions; and
[0021] [0021]FIG. 2 is a diagram of a retinal ganglion cell under ischemic conditions.
DETAILED DESCRIPTION OF THE INVENTION
[0022] While not wishing to be bound by theory, it is believed that the death or loss of axons and associated cell bodies comprising the optic nerve is the result of a lethal increase in the intracellular concentration of calcium ion (Ca +2 ) resulting from an influx of sodium ion (Na + ) through. a non-inactivating sodium ion channel. While studies have been conducted on rat optic nerve segments (Stys et al, 1995; Waxman, 1995), no application has been made to ganglion cells. There is no expectation of altering a similar sequence of pathological events in retinal cells to prevent death thereof after anoxia based on earlier experiments on rat optic nerves because it is unclear whether (1) a similar sequence of events takes place during glaucoma or (2) whether noninactivating Na channels are present in mammalian retinal ganglion cells, and, if present, the role these. channels play in the destruction of retinal ganglion cells that accompanies vision loss associated with glaucoma.
[0023] The procedure in rat retinal ganglion cell is as follows:
[0024] Following depolarization excitable voltage-dependent Na channels open for about one millisec and then close. Provided the cell membrane remains depolarized, the chancels will not reopen until the membrane is repolarized towards its resting state. In contrast to normal excitable Na channels, non-inactivating Na channels can be open at normal resting membrane potentials and can remain open at depolarized potentials. Under pathophysiological conditions such as adenosine triphosphate (ATP) depletion or sustained depolarization Na influx through non-inactivating Na channels can substantially increase intracellular Na. This increase in intracellular Na causes the electrogenic Na/Ca 2+ exchanger (Ransom et al, 1993; Stys, 1995, Waxman et al, 1992) which normally operates to promote efflux of Ca 2+ from the cell to reverse operation with a resulting large increase in intracellular Ca +2 concentration. The Ca +2 concentration of the cell may increase from nanomolar to micromolar levels with the resulting death of said neuronal cell. (Large increases in intracellular Ca +2 have been associated with neuronal cell death and prevention of the increase of intracellular Ca +2 concentration has been shown to protect neurons of the central nervous systems, and rat optic nerve.) In the optic nerve preparation intracellular Ca2+ was not measured, however, normal cell Ca 2+ in most cell types including neurons is approximately 100-200 nanomolar. When Ca 2+ rises to micromolar levels it becomes toxic. Exactly what level of Ca 2+ in optic nerve triggers cell destruction is not known or at least has not been reported.
[0025] Thus, the compounds utilized in accordance with the method of the present invention and in the compositions of the present invention are sodium channel blockers which block the non-inactivating sodium ion channels of the retinal ganglion cells. The sodium channel blockers of the present invention prevent the influx of sodium ions into the neuronal cell through the non-activating sodium channel. Preferably the sodium channel blockers of the present invention will selectively block said non-inactivating sodium channels as opposed to voltage-gated sodium ion channels that inactivate rapidly.
[0026] Pharmaceutically acceptable salts of the sodium channel blockers can also be used in accordance with the present invention. A pharmaceutically acceptable salt may be any salt which retains the activity of the parent compound and does not impart any deleterious or untoward effect on the subject to which it is administered and in the context in which it is administered.
[0027] Such a salt may be derived from any organic or inorganic acid or base. The salt may be a mono or polyvalent ion. Or particular interest where the acid function is concerned are the inorganic ions, such as alkali ions, e.g. sodium, potassium, etc. Organic amine salts may be made with amines, particularly ammonium salts such as mono-, di- and trialkyl amines, e.g. alkyl amines wherein each alkyl group may comprise up to six carbon atoms, or ethanol amines. Salts may also be formed with caffeine, tromethamine and similar molecules. It is only important that the cation of any salt of a sodium channel blocker utilized in the compositions or methods of this invention be able to block the non-inactivating sodium channels of the retinal ganglion cell.
[0028] For protecting against retinal ganglion cell damage in a mammalian eye, and particularly for prevention of retinal ganglion cell loss in humans exposed to a condition that causes optic neuron loss, the active compounds (or mixtures or salts thereof) are a ministered in accordance with the present invention to the eye admixed with an ophthalmically acceptable carrier. Any suitable, e.g., conventional, ophthalmically acceptable carrier may be employed. A carrier is ophthalmically acceptable if it has substantially no long term or permanent detrimental effect on the eye to which it is administered. Examples of ophthalmically acceptable carriers include water (distilled or deionized water), saline and other aqueous media. In accordance with the invention, the active compounds are preferably soluble in the carrier which is employed for their administration so that the active compounds are administered to the eye in the form of a solution. Alternatively, a suspension of the active compound or compounds (or salts thereof) in a suitable carrier may also be employed.
[0029] In accordance with the invention the active compounds (or mixtures or salts thereof) are administered in an ophthalmically acceptable carrier in sufficient concentration so as to deliver an effective amount of the active compound or compounds to the optic nerve site of the eye. Preferably, the ophthalmic, therapeutic solutions contain one or more of the active compounds in a concentration range of approximately 0.0001% to approximately 1% (weight by volume) and more preferably approximately 0.0005% to approximately 0.1% (weight by volume).
[0030] Any method of administering drugs to the retinal ganglion cell site of a mammalian eye may be employed to administer, in accordance with the present invention, the active compound or compounds to the eye to be treated. By the term “administering” is meant to include those general systemic drug administration modes, e.g., injection directly into the patient's blood vessels, oral administration and the like, which result in the compound or compounds being systemically available. Also, inter-cameral injection may be utilized to deliver the sodium channel blocker to the retinal ganglion cell site. The primary effect on the mammal resulting from the direct administering of the active compound or compounds to the mammal's eye is the prevention of optic nerve loss. Preferably, the. active useful compound or compounds are applied topically to the eye or are injected directly into the eye.
[0031] Injection of ophthalmic preparations, for example ocular drops, gels or creams may be used because of ease of application, ease of dose delivery and fewer systemic side effects, such as cardiovascular hypotension. An exemplary topical ophthalmic formulation is shown below in Table I. The abbreviation q.s. means a quantity sufficient to effect the result or to make volume.
TABLE I Ingredient Amount (% W/V) Active Compound in accordance about 0.0001 to with the invention, about 1 Preservative 0-0.10 Vehicle 0-40 Tonicity Adjustor 1-10 Buffer 0.01-10 pH Adjustor q.s. pH 4.5-7.5 antioxidant as needed Purified Water as needed to make 100%
[0032] Various preservatives may be used in the ophthalmic preparation described in Table I above. Preferred preservatives include, but are not limited to, benzalkonium potassium, chlorobutanol, thimerosal, phenylmercuric acetate, and phenylmercuric nitrate. Likewise, various preferred vehicles may be used in such ophthalmic preparation. These vehicles include, but are not limited to, polyvinyl alcohol, povidone, hydroxyropyl methyl cellulose, poloxamers, carboxymethyl cellulose and hydroxyethyl cellulose.
[0033] Tonicity adjustors may be added as needed or convenient. They include, but are not limited to, salts, particularly sodium chloride, potassium chloride, etc., mannitol and glycerin, or any other suitable ophthalmically acceptable tonicity adjustor.
[0034] Various buffers and means for adjusting pH may be used so long as the resulting preparation is ophthalmically acceptable. Accordingly, buffers include but are not limited to, acetate buffers, citrate buffers, phosphate buffers, and borate buffers. Acids or bases may be used to adjust the pH of these formulations as needed.
[0035] In a similar vein, ophthalmically acceptable antioxidants include, but are not limited to, sodium metabisulfite, sodium thiosulfate, acetylcysteine, butylated hydroxyanisole, and butylated hydroxytoluene.
[0036] Those skilled in the art will recognize that the frequency of administration depends on the precise nature of the active ingredient and its concentration in the ophthalmic formulation.
[0037] Specific examples of sodium channel blockers which are used as the active effective ingredients in the ophthalmic compositions of the present invention are described as benzothialzole, phenyl benzothialzole, disopyramide, propafenone, flecainide, lorcainide, aprindine, encainide, GEA-968, azure A, pancuronium, N-methylstrychnine, CNS 1237, BW1003C87, BW619C89, U54494A, PD85639, ralitoline, C1953, lifarizine, zonisamide and riluzole.
[0038] A sodium channel blocker, in accordance with the present invention, may be identified by the methods disclosed in “The Extracellular Patch Clamp: A Method for Resolving Currents Through Individual Open Channels in Biological Membranes”, Neher et al Pflugers Archiv V375 pp 219-228 (1978) and “Improved Patch-Clamp Techniques for High-Resolution Current Recording from Cells and Cell-Free Membrane Patches”, Hamill et al Pflugers Archiv V391 pp 85-100 (1981). These references are to be incorporated herein in toto for providing a method for identifying sodium channel blockers useful in accordance with the present invention.
EXAMPLE
[0039] [0039]FIG. 1 shows a representation of a retinal ganglion cell 10 , under normal conditions and assumed relevant transport mechanisms 12 , 14 , 16 , 18 responsible for maintaining the sodium (Na + ), potassium (K + ) and calcium (Ca 2+ ) gradients and electrical activity of the cell. As shown under normal conditions ATP levels are adequate and furnish the fuel needed to drive the Na + /K + pump 14 that maintains the K + and Na + gradients, keeping intracellular concentrations of K + high and Na + low relative to their respective extracellular concentrations. The voltage-gated Na + and K + channels 12 , 16 provide the currents that make up the action potential. The electrogenic Na + /Ca 2+ , exchanger 18 keeps cellular Ca 2+ levels within the physiological range (nanomolar)
[0040] If, however, ATP levels should drop, due to some pathophysiological insult, the axon will depolarize and the Na + /K + gradients will collapse over time as a result of Na + /K + pump 14 inhibition as shown in FIG. 2 for a cell 20 under ischemic conditions. The rise in cellular Na + is mediated by a subset of voltage-gated Na + channels that do roe inactivate over time. These Na + channels are coined “noninactivating”. The combination of membrane depolarization and intracellular Na + increase is sufficient to drive the Na + /Ca 2+ exchanger 18 backwards (see FIG. 2) such that the ganglion cells load with lethal levels of Ca 2+ . It is assumed that this scenario occurs in the retinal ganglion cell in glaucoma.
[0041] Accordingly, in accordance with the present invention the following sequence is expected in the presence of a therapeutic concentration of a Na + channel blocker selective for the noninactivating type. First, the Na + channel blocker would have little or no effect on the normal action potential. This is crucial for normal ganglion cell function. Second, it will block the deleterious increase in cell Na + and the subsequent lethal increase in cell Ca 2+ . Thus, normal ganglion cell dysfunction will be minimized and therefore help prevent the loss of visual field associated with glaucoma. In addition, blockers of noninactivating Na + channels may yield an additional benefit. This is because Na + channels are thought to help prevent excitotoxic glutamate release which occurs in neuronal tissue during ischemia, hypoxia and other pathological conditions. Excessive extracellular glutamate levels are neurodestructive and thus may also be involved in glaucomatous optic neuropathy. Thus, Na + overload and excitotoxic increase in extracellular glutamate in accordance with the present invention may be prevented by a therapeutic concentration of one drug, a blocker of noninactivating Na + channels.
[0042] In view of the above, it is clear that the scope of the present invention should be interpreted solely on the basis of the following claims, as such claims are read in light of the disclosure.
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A method and composition for altering a plausible sequence of pathological events in retinal ganglion cells associated with glaucoma, the sequence including membrane depolarization, influx of millimolar amounts of Na + via non-inactivating Na + channels, and the lethal elevation of cell Ca 2+ due to reversal of the Na + /Ca 2+ exchanger. The method includes blocking, by administration of a selected composition, of associated, non-inactivating Na + channels in retinal ganglion cells in order to limit Na + /Ca + exchange in the retinal ganglion cells and prevent buildup of the Ca 2+ level in the retinal ganglion cells to a lethal level. The results in a method of preventing retinal ganglion cell death, associated with glaucoma, by administering to the optic nerve of a mammal, a compound which blocks the non-inactivating sodium ion channels of the optic nerve. Alternately, said invention relates to a method of preventing optic retinal ganglion cell death in a human by administering to the retinal ganglion cells of said human a compound which blocks the non-inactivating sodium ion channel of the retinal ganglion cells.
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BACKGROUND OF THE INVENTION
[0001] Hot beverages, normally coffee, tea or the like, are frequently sold as a take-out item and supplied in disposable cups with thin plastic lids. Such lids are generally of two types, lids which are to be removed in their entirety for access to the contents of the cup, and lids which utilize a fold-back or tear back flap to expose a large drinking opening.
[0002] If the lid is to be removed in its entirety when consuming the contents of the cup, the lid will frequently include a sipping opening which allows the consumer to cautiously sip the beverage until such time as the coffee has sufficiently cooled to allow for a direct drinking thereof from the cup. In those lids wherein a closure flap is provided, the opening formed upon removal of the flap must be quite substantial to allow for a drinking of the coffee in a normal and rather high flow manner. Sipping through such an opening, particularly when the beverage is very hot, can be troublesome.
[0003] As consumer preferences in lids will vary, a supplier of the dispensed beverage will frequently have to stock both types of lids to meet customer requirements.
[0004] Patents of general interest with regard to the environment of the invention include Lane et al, U.S. Pat. No. 5,699,927 wherein the lid, in addition to providing an enlarged drinking opening with a closure flap, also includes a small vent 74 opening within a rather deep recess 72 for the venting of steam. Such a steam venting hole would have no sipping capability.
[0005] Another such patent is Zettle et al, U.S. Pat. No. 6,783,019 B2 which, in addition to an enlarged drinking opening or spout 108 through the lid itself, also includes a straw hole 106 with a gasket 200 . This hole, because of its structure specifically for the accommodation of a straw, is unlikely to be used to access hot liquids. Further, positioning of the straw opening substantially inward from the edge portion of the lid will preclude any possibility of a cautious sipping of the cup contents therethrough.
[0006] The patent to Warden et al, U.S. Pat. No. 5,398,843 discloses a breakout section which is pushed inward to provide a drinking opening. This patent also discloses a highly restricted vent opening which is probably necessary to facilitate flow of fluid through the rather restricted drinking opening, and clearly is not intended to, and could not, as constructed, permit a sipping therethrough.
SUMMARY OF THE INVENTION
[0007] The present invention is particularly directed to a multiple function cup lid which can, at the option of the user, allow a controlled sipping, as would be desirable when the contents of the cup are too hot for a conventional drinking, and an unrestricted drinking of the contents as the liquid cools. The capability of the single lid of the invention to provide for two modes of direct access to the contents of a hot container, without removal of the lid, avoids the necessity of providing a separate lid for each drinking mode. Rather, both modes are accommodated by a unique single lid.
[0008] Basically the lid, formed of a conventional thermoplastic material or the like, provides a tear back flap joined by an integral or living hinge to a central portion of the lid body. The flap, when closed and prior to tearing or breaking away, has an outer rim portion defining a downwardly opening cavity which frictionally engages the conventional beaded lip of a cup. The remainder of the lid has a similarly configured peripheral rim for sealing of the entire lid to the container or cup. The flap, when a drinking of the contents of the cup is desired, will, through a lifting of the rim portion of the flap, break away and pivot rearwardly. This will expose the lip of the cup itself for a direct engagement of the user's lips with the cup lip and a direct drinking of the contents, as would be the case were the entire lid removed, while still retaining a substantial protective enclosure of the cup contents.
[0009] The lid, in an area diametrically aligned with the flap, also includes a raised ridge at the outer periphery of the lid. This ridge is provided with the sipping opening therethrough aligned with the tear flap. The positioning of the sipping opening in the raised portion or ridge, positions the sipping opening substantially above the maximum fill line of the cup, normally at or slightly below the beaded lip thereof. In addition, the ridge uniquely provides for a convenient access to the sipping opening by the mouth of the drinker with the lips positioned to each side thereof for controlled access to the contents in the sipping mode.
[0010] When drinking through the drinking opening, it is desirable to close the sipping opening which, while relatively small, is clearly larger than a restricted vent opening through which accidental discharge is not normally a problem. Accordingly, a projecting tab is integrally formed with the rim portion of the flap and extends beyond the rim forming periphery of the lid. This tab, upon an opening of the flap and a swinging of the flap fully backward, will engage over and close the sipping opening. This closing of the sipping opening is enhanced and an effective seal thereof provided, by a projecting lug on the tab configured to conform to the configuration of the sipping opening for a snug engagement therein. The engagement of the lug in the sipping opening will also act so as to hold the flap in its open position.
[0011] Further objects and features of the invention will become apparent from the detailed description of the invention following hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a top perspective view of the lid of the invention mounted to a hot cup with the tear flap closed and with the sipping opening open;
[0013] FIG. 2 is a similar perspective view with the tear flap released and pivoted rearwardly to overlie the lid and seal the sipping opening;
[0014] FIG. 3 is an enlarged cross-sectional detail of the lid itself taken substantially on a plane passing along line 3 - 3 in FIG. 1 with the flap in its closed position; and
[0015] FIG. 4 is an enlarged cross-sectional detail through the lid itself taken substantially on a plane passing along line 4 - 4 in FIG. 2 and illustrating the flap in its open position.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] Referring now more specifically to the drawings, the hot cup lid 10 of the invention is illustrated, in FIGS. 1 and 2 , engaged over the open mouth of a hot cup 12 . The cup 12 , in the manner of conventional hot cups, includes an outwardly rolled edge about the open mouth thereof which defines a cup lip 14 . The lid 10 includes a top or top panel 16 and a peripheral rim 18 adapted to snap-mount and seal to the cup lip. The lid rim 18 , noting FIGS. 3 and 4 , includes a downwardly directed cavity 20 which seats on the cup lip 14 , an outer skirt 22 , preferably including an inwardly directed locking bead 24 , and an inner rim skirt 26 defining the cavity 20 and engageable against the inner surface of the cup 12 .
[0017] The height of the top 16 above the peripheral rim 18 varies from a maximum height with a side wall 28 extending between the top 16 and the inner rim skirt 26 therebelow to a generally diametrically opposed position wherein the top 16 engages directly with the inner rim skirt 26 substantially below the cavity 20 defined thereby. Basically, the top 16 is of a constant height for a substantial portion of the lid 10 and, at a break point indicated by 30 , slopes, as indicated at 32 , progressively downward, to the rim, with a corresponding progressive decrease in the height of the lid side wall 28 . Note in particular the left side of the cross-sectional details of FIGS. 3 and 4 .
[0018] The lid 10 includes a central recess 34 , the depth of which below the top 16 is such whereby the bottom 38 of the recess 34 is positioned substantially above the peripheral rim 18 . The recess 34 is of a size and so configured as to define or retain a peripheral ridge 40 about a major portion of the lid, including the full height portion thereof and an extent of the downwardly sloping area 32 , note in particular FIGS. 1 and 2 . This ridge 40 is defined by the flat top 16 , the side wall 28 and an inner wall 42 which also defines the peripheral wall of the recess 34 .
[0019] A flap-accommodating channel 44 extends radially outward from the relatively higher recess bottom 38 centrally through the sloping portion of the top 16 to the cup rim 18 .
[0020] A tear flap 46 extends centrally along the channel 44 and is defined by laterally spaced parallel tear or break lines 48 in and along the bottom of the channel 44 and through the aligned section or portion 50 of the lid rim 18 . The inner end of the flap 46 is pivotally joined to the bottom 38 of the recess by an appropriate living hinge 52 . The flap also includes an integral tab 54 on and projecting outward from the outer skirt portion of the rim portion 50 of the flap with this tab 54 , having an upwardly projecting sealing lug 56 thereon.
[0021] The flap 46 , when one desired to drink from the cup 12 , is grasped by the tab 56 and upwardly and rearwardly pivoted, causing a parting of the tear or break lines 48 as well as a disengagement of the rim portion 50 integral therewith. The drinking opening thus formed is of a substantial size and, by a removal of the rim portion 50 with the flap, exposes the cup lip 14 for direct access thereto by the drinker, much in the manner of drinking from an open top cup. This substantially free access to the contents of the cup will also be facilitated by the inclined nature of the portion 32 of the top, which allows for an accommodation of the upper lip of the drinker. As desired, the bottom of the channel 44 can be strengthened or stabilized immediately outward of the tear lines 48 by a pair of downwardly directed ribs 60 formed therein and paralleling the tear lines 48 for a major portion of the length thereof.
[0022] The top 16 , and more particularly the flat top ridge portion thereof formed by the recess 34 , at a point diametrically opposed from the flap and opening 48 formed thereby, includes a sipping opening 62 therethrough. This sipping opening 62 is, as opposed to the drinking opening 58 , of a size so as to allow for a controlled sipping of the hot contents of the cup therethrough until such time as the contents have sufficiently cooled so as to allow for a conventional drinking thereof through the drinking opening 58 . It will be noted that this sipping opening 62 is provided immediately adjacent the outer periphery of the lid for convenient and safe access thereto and to the hot liquid to issue therefrom in a controlled manner. Further, the ridge 40 within which the sipping opening 62 is defined, allows for a convenient positioning of the mouth of the drinker when accessing the sipping opening. The elevated positioning of the sipping opening 62 at the uppermost position of the lid, will also provide for at least a small cooling effect as the hot liquid flows through the lid to the sipping opening.
[0023] Referring to FIGS. 2 and 4 in particular, when the larger drinking opening 58 is to be accessed, the flap 46 is upwardly and rearwardly pivoted and releasably retained in its open position by engagement of the lug 56 on the tab 54 within the sipping opening 62 . The sipping opening and lug are of complimentary configurations whereby the lug completely seals the sipping opening to prevent any accidental discharge therefrom as the drinking opening 58 is accessed. Further, in order to accommodate the projecting rim section 50 integral with the flap 46 , and thus not interfere with the sealing engagement of the lug 56 within the sipping opening 62 , a pocket or pocket area 64 will be provided at the rear of the recess 34 immediately forward of the ridge 40 within which the sipping opening 62 is defined. The pocket 64 , as will be readily recognized, is appropriately aligned to receive the rim section 50 . It will also be recognized that this pocket 64 , will provide for a further accommodation of the lid to the drinker's mouth as the sipping opening is accessed.
[0024] Inasmuch as the flap 46 incorporates a section or portion 50 of the locking rim 18 , the flap can be reclosed for a substantially resealing of the drinking opening. It should also be appreciated that the hot cup lid of the invention can be formed of any appropriate thermoplastic or like material standard in the formation of cup lids and which will allow for the provision of tear or break lines, a living hinge, and a snap mounting of the lid rim and flap rim portion to a conventional hot cup.
[0025] As described, the lid is unique in its multi-functional capacity, providing, at the option of the drinker, a sipping of the contents of the cup through a small sipping opening upwardly removed from the fill level of the cup, and, upon a sufficient cooling of the cup contents to the drinker's preference, a direct drinking through an enlarged drinking opening provided in the lid which exposes the cup lip itself and provides direct access to the contents thereof as one would have in an open mouth cup. This is achieved while at the same time retaining a partial enclosure of the cup to maintain the warmth thereof and avoid accidental spillage.
[0026] The foregoing is considered illustrative of the principles of the invention. As modifications and variations may occur to those skilled in the art, it is not desired to limit the invention to the exact construction and manner of use as shown and described. Rather, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention as claimed.
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A hot cup lid providing alternating modes of access to the contents of a cup, the lid including an enlarged drinking opening selectively closed by a tear flap, and a smaller sipping opening diametrically aligned with the drinking opening and adjacent the periphery of the lid, the tear flap including a sealing lug thereon engageable within and closing the sipping opening upon pivotal movement of the flap to open the drinking opening.
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BACKGROUND
[0001] Sumps, also referred to as catch basins, have traditionally been utilized in chemical, petrochemical, metal finishing, industrial and municipal operations to capture the flow of hazardous materials. Due to the development and implementation of storm water runoff regulations, the use of sumps is now common in parking lots, salvage yards, scrap yards, and anywhere that rain can combine with oil, grease, fuel, or other hazardous materials. The sumps are typically located in holes dug out of the pavement so that only their upper surface is exposed, allowing run-off to collect directly into the sump. The concrete or asphalt surrounding a sump is generally sloped to the sump to provide for gravitational flow and capture.
[0002] In current constructions, sumps are commonly constructed from a layer of concrete with a protective coating of tile, brick, or FRP. Other solutions include molded single wall tanks, however these tanks have a tendency to lift or “float” out of their hole and become either damaged or unusable. Anchored sumps of these types are traditionally expensive because the materials necessary to create the anchored sump are costly and there is relatively significant fabrication labor.
SUMMARY OF THE INVENTION
[0003] The present invention overcomes the shortcomings of the prior art and comprises a seamless, rotationally molded double wall sump. The seamless, one piece double wall design is unique to the industry and has inherent advantages over previous designs. The dual wall design provides insurance against leakage, and the seamless design prevents seepage or leaks from penetrating the sump. The double wall design may be molded with a fabric faced grating seat as an integral part. The design results in a cost effective, high performance solution that can be produced in large quantities with relatively little labor costs compared with previous sump manufacturing concepts. The double walls form a gap that may be filled with a foam stiffener to further increase the rigidity and strength of the sump.
[0004] For both retrofit and new construction, the sump of the present invention is cast-in-place using standard concrete materials and methods. That is, the sump is placed into wet cement formed in a pit and allowed to harden around the sump. The adjoining ground level is set such that any liquids within the immediate area will flow to the sump for further disposition which can include outlet piping for gravity flow to a larger collection tank. Or, the sump can be equipped with a level control device and relays to activate a pump for “lifting” or transferring the liquids to another location for storage and/or treatment. The integral ribs of the secondary containment portion of the sump function to “lock” the sump into the surrounding concrete to prevent flotation of the sump in “high water table/empty sump” conditions. The integral fabric face, which can be a polyester or polypropylene sheet, is located on the vertical side and top of the grating seat to allow the thermoplastic sump to be effectively integrated with the chemically resistant flooring system being applied to the surrounding concrete floor. This feature provides for the isolation of the interface between the sump and concrete.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is top view of the sump of the present invention without the grate;
[0006] FIG. 2 is a cross sectional view of the sump of FIG. 1 ; and
[0007] FIG. 3 is a cross-sectional view of the sump in ground with a pump installed to purge collected waste.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] A sump 10 of the present invention is generally shown in FIGS. 1-3 , comprising a cylindrical body 12 having two integrally molded vessels that form a double walled container. The first vessel 14 is a primary containment vessel that forms the interior of the sump 10 and is used to collect the various materials that the sump is designed to capture. The outer or secondary vessel 16 is a redundancy guard against leakage and is molded with the primary vessel to form a seamless integral one-piece unit of double wall construction. Between the two walls is a gap that may be filled with a stiffening foam 18 or other stiffening agent that can be injected between the two walls of the sump 10 during the molding process. The rigidity of the sump 10 is most critical at the upper portion of the sump, since the sump 10 is typically buried in the ground 20 (See FIG. 3 ) and surrounded by concrete. If the upper portion of the sump is flexible, it can separate from the concrete and create gaps at the surface between the secondary vessel and the ground that can allow contaminants to seep between the cement and the sump, leading to contamination, corrosion, and other deleterious effects.
[0009] The outer surface of the secondary vessel 16 is formed with a plurality of ribs 22 that protrude radially outward, preferably in concentric circles, and serve as anchors for the sump 10 to prevent the sump from lifting or “floating” in the concrete. First the ground is excavated and then wet cement is poured into the hole to create the base for the sump 10 . Before the concrete sets, the double walled sump 10 is placed on the cement and additional cement poured around the walls to encase the sump 10 in wet cement until only the upper edge 24 of the sump 10 is visible in the concrete. The wet cement fills the gaps 26 between the ribs 22 , and as the cement hardens the ribs 22 and the interleaving cement ridges formed in the gaps 26 prevent the sump from rising upward.
[0010] The sump 10 may be formed with a first port 28 along the lower surface that can be used to drain the sump as it fills with materials. Piping (not shown) connecting the sump through the port 28 can be gravity fed, so that as material collects when it reaches the port it is carried away under the influence of gravity to a collection area. Alternatively, the port and connecting piping can be coupled to a pump 30 that extracts the material collected in the sump. The pump 30 can be manually actuated, timer actuated, or it may be actuated upon the signaling of a fluid level sensor (not shown) incorporated into the sump. The level sensor determines the level of the collected waste in the sump 10 , and sends a signal to the pump 30 when the level reaches a predetermined position or elevation in the sump to prevent overflow. Alternatively, the level sensor may send a signal to a processor (now shown) remote from the sump that can be used to actuate the pump 30 or other drainage measures.
[0011] The sump 10 may be configured with a leak detection sensor 32 to warn if the primary container 14 becomes compromised. If the primary container 14 forms a crack or loses integrity, waste will enter the area between the primary container 14 and the secondary container 16 , collecting at the bottom of the gap between the two walls. If sensor 32 is placed at the bottom of the gap, it can send a signal to a nearby microprocessor to send an alarm that the sump needs repair. The leak detector can be as standard detector that detects a change in resistance or capacitance when in contact with a liquid.
[0012] It is preferable to have the surround ground 20 area adjacent the sump contoured or sloped so that all run-off will collect into the sump via gravity. The sump may also have a second port 36 that leads other collection areas into the sump, such that the sump acts as a localized collection reservoir. The sump 10 may also preferably be formed with a circumferential upper lip 38 that retains a grate 40 , such as a fiberglass grate, so that the opening of the sump 10 is not a hazard that workers can fall into.
[0013] The foregoing description is intended solely to be exemplary and not limiting as to the scope of the invention. There are many alterations and modifications that would be understood by one of ordinary skill in the art, and the invention is intended to include all such modifications, particularly as to pertains to use, materials, shape, dimension, and the like. For example, the sump could take on a rectangular shape without departing from the spirit or scope of the invention, or could be made from other materials suitable for the particular application. Thus, the invention should be construed to cover all such modifications and alterations, consistent with the language of the claims herein construed using their ordinary and customary meanings without limitation to anything depicted in the drawings or any descriptions above unless expressly limited.
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A seamless, double-walled sump is disclosed for collecting run-off materials and waste products. The sump includes a primary containment vessel and a secondary vessel, integrally molded into a single seamless unit. The sump includes a plurality of ribs that cooperate with surrounding concrete or other enclosing material to anchor the sump and prevent floating. The sump may also include a fabric outer layer that serves as an interface between the concrete and the sump to prevent corrosion.
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BACKGROUND OF THE INVENTION
The invention has as its subject a liquid separating and evacuating device for fluid suction equipment and, in particular, for dental surgery equipment.
DESCRIPTION OF THE PRIOR ART
During treatment given inside the mouth, dental treatment for example, it is impossible for the patient to swallow the saliva produced by the salivary glands located in the mouth itself. Furthermore, while the said treatment is taking place the flow of blood and the use of various liquid substances is frequent, and the said liquids have to be evacuated along with the saliva.
For this purpose a probe connected to a suction pump is inserted in the mouth of the patient, the latter attending to the evacuation of the liquids held inside the mouth itself.
The fluid extracted, normally consisting of air, saliva, blood and various liquids, depending upon the type of treatment being given, can be made to pass thru the pump and to be discharged externally. To do this, however, can jeopardize the satisfactory operation and the life span of the pump since the liquids present in the fluid are corrosive and the cause of encrustment.
In order to overcome this particular problem a device can be inserted in the suction tube, between the pump and the probe, which separates the liquids from the air and looks after the discharging externally of the said liquids.
Centrifugal separating devices exist at the present time, and these virtually consist of a container into which the sucked fluid enters in a tangential direction. In this way the liquids adopt a vortical downward motion and are discharged in a continuous fashion from below.
The said devices are provided with a float which, with the aid of suitable contrivances, interrupts the suction of the pump at the time the liquid inside the container reaches too high a level, and when this occurs the liquid is discharged by gravity. When the level of the liquid drops, the float sets the suction pump back in motion, and the vortex of the liquid is re-created.
One problem with this type of separating device is that it requires a motor of high power to be used for the suction pump in order to enable the suction circuit to operate properly.
Another problem is that the suction pump is constantly and rapidly switched on and off when the quantity of liquid arriving is high.
SUMMARY OF THE INVENTION
One object of the invention is to overcome the aforementioned difficulties by making available a separating and evacuating device which does not require a motor of high power to be used for the suction pump and which, during operation, does not constantly and rapidly switch the said pump on and off, though it does allow a large quantity of liquid to be separated and evacuated.
Another object of the invention is to make available a separating and evacuating device that is highly reliable yet simple from the operating viewpoint.
These and other objects too are attained with the device in question, essential features of which are that it comprises: a first chamber into which the fluid extracted arrives, this being designed to effect the separation from the air of the liquid part of the fluid extracted, kept, during the operation of the device, at a pressure less than that of the atmosphere; a second chamber placed beneath the said first chamber; automatic means, tripped by the level of the liquid present in the first chamber, designed to alternately create in the said second chamber a pressure approximately identical to that of the atmosphere when the level of the liquid in the first chamber is lower than a pre-set value, and a pressure approximately identical to that of the first chamber when the level of the liquid in the first chamber is above the said pre-set value; and valve means designed to alternately allow and prevent liquid from passing from the said first chamber to the said second chamber, and to alternately allow and prevent liquid from passing from the said second chamber to the outside, the passing of the liquid from the first to the second chamber being allowed when the two chambers are at approximately the same pressure and being prevented when the pressure of the second chamber is approximately identical to that of the atmosphere, the passing of the liquid from the second chamber to the outside being allowed when the pressure of the second chamber is approximately identical to that of the atmosphere and being prevented when the pressure of the second chamber is approximately identical to that of the first chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the invention will emerge more obviously from the detailed description that follows of one preferred but not sole form of embodiment for the device in question, illustrated purely as an unlimited example on the accompanying drawings, in which:
FIG. 1 shows, in a view seen from above, the device forming the subject of the invention, with certain parts removed in order that others may be seen more clearly;
FIG. 2 shows, in a reduced scale, a section of the device along the plane followed by the line II--II in FIG. 1;
FIG. 3 shows, in a reduced scale, a section of the device along the plane followed by the line III--III in FIG. 1;
FIG. 4 shows, in a reduced scale, a section of the device along the plane followed by the line IV--IV in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The separating and evacuating device (1) in question is virtually constituted by a cylindrical container (2) placed on a vertical axis, the upper edge (2a) of which is hermetically connected, thru two elastic rings (7a) and (7b), to a covering member (3). The container (2) is divided, by means of a partition (4) positioned in a substantially horizontal fashion, into two areas that constitute a first chamber (5) and a second chamber (6) placed beneath the said first chamber (5).
The first chamber (5) communicates directly with a suction pipe (8), machined in the covering member (3), which is in turn connected, thru a first flexible tube (9), one extremity of which is visible in the drawing, to a suction pump that is not illustrated. During operation, the first chamber (5) is maintained, thru the said suction pump, at a pressure below that of the atmosphere. The suction pipe (8) has two extremities, (8a) and (8b), respectively, to each of which it is possible, depending on the space available for the installation of the device (1), to connect the flexible tube (9). In the example illustrated, the tube (9) is connected to the extremity (8a), while the extremity (8b) is sealed by a first cover (10). The first chamber (5) communicates directly with an inlet pipe (11), machined in the covering member (3) which, in turn, is connected, thru a second flexible tube (12), one extremity of which is visible in the drawing, to one or more suction probes that extract fluid from the mouth of the patient. When the device is in operation, the fluid extracted, deprived of any solid bodies thru the use of a non-illustrated filter placed in the inlet pipe (11), passes into the first chamber (5) wherein the separation of the liquids from the air takes place, and the former drop downwards towards the bottom of the said chamber. The inlet pipe (11) has two extremities, (11a) and (11b), respectively, to each of which it is possible, depending on the space available for the installation of the device (1), to connect the flexible tube (12). In the example illustrated, the tube (12) is connected to the extremity (11a), while the extremity (11b) is sealed by a second cover (14).
In order to prevent part of the liquid from being drawn by the pump thru the suction pipe (8), both this and the inlet pipe (11) are so arranged as to not face each other. Provision is made in the partition (4) and in a bottom wall (15) with which the container (2) is provided, for a first mushroom valve (16) and a second mushroom valve (18), respectively, which constitute valve means for alternately allowing and preventing the liquid from passing from the first chamber (5) to the second chamber (6), thru the valve (16), and the liquid from passing from the second chamber (6) to the outside, thru the valve (18).
The valves (16) and (18) are arranged in such a way that their opening takes place thru a downward movement of the obturation means (16a) and (18a), respectively. In this way liquids are allowed to pass from the first to the second chamber when chambers (5) and (6) are at approximately the same pressure since the obturation means (16a) of the valve (16) drop by gravity and open the passage but are prevented from doing this when the chamber (6) is at a pressure approximately identical to that of the atmosphere since the said difference in pressure existing between the two chambers (as stated, the first chamber (5) is, during operation, always at a pressure below that of the atmosphere) pushes the obturation means (16a) of the valve (16) upwards against the set of the valve until the passage for the liquid is closed. Likewise the valve (18) allows the liquid to pass from the second chamber (6) to the outside when the chamber (6) is at a pressure approximately identical to that of the atmosphere, and prevents the said passing of the liquid when the chamber (6) is under vacuum with respect to the outside (particularly when the chamber (6) is at an almost identical pressure to that of the chamber (5)).
The device (1) comprises automatic means, tripped by the level of the liquid present in the first chamber (5), designed to alternately create in the said second chamber (6) either a pressure approximately identical to that of the atmosphere, when the level of the liquid in the first chamber (5) is below a pre-set value, or a pressure identical approximately to that of the first chamber (5), when the level of the liquid in the latter is above the pre-set value.
The said automatic means comprise a pneumatic distributor (20) whose body is machined in the covering member (3). In the cylindrical cavity (20b) inside the body (20a) of the distributor, placed on a vertical axis and communicating directly with the first chamber (5), slides a cursor (21) connected integrally, on a vertical axis, to one extremity of a rigid rod (22) positioned vertically. The other extremity of the rod (22) is connected integrally to a float (23) contained in the first chamber (5).
The said float (23) is designed to pass to the automatic means an operating signal determined by the level of the liquid present in the first chamber (5). Depending on the position adopted by the float (23), the cursor (21) slides in the cavity (20b) of the distributor (20) and either opens or closes the paths of the said distributor.
Furthermore, the automatic means comprise a pneumatic valve (24) whose obturation means are constituted by a diaphragm (25) actuated by the distributor (20). The said valve (24) is constituted by a lower annular cavity (26) placed on a vertical axis and communicating directly, via an external channel (27), with the second chamber (6) and alternatively either with the outside or with the first chamber (5), and by an upper cavity (28) placed in communication, via the channels described hereinafter, with the annular cavity (26), on a horizontal contact plane, with the interposition of the diaphragm (25), the non-operative position of which defines the horizontal contact plane. In its central area the annular cavity (26) is provided with a coaxial hole (30), the upper extremity (30a) of which is at an elevation slightly less than that of the said contact plane and communicates directly with the first chamber (5).
The pneumatic distributor (20) and the pneumatic valve (24), operated by the level of the liquid present in the first chamber (5) thru the float (20), alternately place the second chamber (6) either in communication with the first chamber (5) or with the outside.
When, in fact, the level of the liquid present in the first chamber (5) is not sufficient to cause the flotation of the float (23) (FIG. 4), the upper cavity (28) of the pneumatic valve (24) is placed in communication with the outside via a first passage constituted by a channel (31) machined in the covering member (3), the extremities of which communicate with the outside and with the cylindrical cavity (20b) of the pneumatic distributor, respectively, by a first groove (32) machined circumferentially in the cursor (21), and by the channels (33) and (34) machined in the inside of the cursor (21). The diaphragm (25) is thrust, by the difference in pressure existing between the upper cavity (28) and the hole (30) in the pneumatic valve, to close the extremity (30a) of the hole (30) (position A shown with dashes in FIG. 3). The annular cavity (26) is placed in communication with the outside via a second passage constituted by a channel (31), by the first groove (32) and by a channel (35) machined in the covering member (3), the extremities of which communicate with the cylindrical cavity (20b) of the pneumatic distributor and with the annular cavity (26) of the pneumatic valve. In this way the second chamber (6) connected, as stated, to the annular cavity (26) is in communication with the outside and is thus at an approximately atmospheric pressure.
When the level of the liquid present in the first chamber (5) is sufficient to cause the flotation of the float (23) (FIG. 3), the cursor (21) is displaced upwards and it closes the first passage and the second passage. The upper cavity (28) of the pneumatic valve (24) is placed in communication with the first chamber (5) and is thus carried to a pressure less than that of the atmosphere via a third passage constituted by the channel (36) machined in the covering member (3), the extremities of which communicate with the hole (30) in the pneumatic valve and with the cylindrical cavity (20b) of the pneumatic distributor, respectively, by a second groove (38) machined circumferentially in the cursor (21) in a position underneath the first groove (32), and by a channel (40) machined in the covering member (3), the extremities of which communicate with the cylindrical cavity (20b) and with the upper cavity (28), respectively.Because of the vacuum existing in the cavity (28), the diaphragm (25) rises from the extremity (30a) of the hole (30), position B in FIG. 3, and allows there to be a communication between the first chamber (5) and the annular cavity (26) and thus between the first chamber (5) and the second chamber (6) which, in this way, is at a pressure approximately identical to that existing in the first chamber.
In order to stop the operation of the suction pump in the event of the fluid extracted containing a greater quantity of liquid that can be evacuated by the device (1), three level measuring contrivances, (50), (51), and (52), respectively, are inserted in the first chamber (5), placed at different heights. This insertion of level measuring contrivances in the chamber (5) is allowed by the tubes (50a), (51a) and (52a), respectively, which are machined in the covering member (3) and place the upper part of this in direct communication with the first chamber (5).
The level measuring contrivances (50), (51) and (52) supply an electric signal when their lower extremity is immersed in the liquid and are so connected electrically as to interrupt the operation of the suction pump when all three have their extremity immersed in the liquid, and to put the pump back in operation when the level of the liquid drops below that of the measuring contrivance (51). In this way it is possible to avoid the motor that operates the suction pump being switched on and off in rapid succession.
The operation of the device in question takes place in the following way: When the suction pump is operated, the first chamber (5) is carried to a pressure below that of the atmosphere. Fluid that enters the first chamber (5) is extracted thru one or more suction probes. Until the level of the liquid allows the flotation of the float (23) the second chamber (6) is, as stated, at atmospheric pressure and thus the valve (16) prevents the liquid from passing from the first to the second chamber and, naturally, air from passing from the second to the first chamber. When the level of the liquid in the chamber (5) is such as to allow the flotation of the float (23), the latter moves upwards (FIG. 3) and places the first chamber (5) in communication, as stated, with the second chamber (6). The valve (16), subject to almost identical pressure both at the top and at the bottom, opens and allows the liquid to pass from the first to the second chamber. Contemporaneously, the valve (18), subjected at the bottom to atmospheric pressure closes and prevents the liquid from passing from the second chamber (6) to the outside and also prevents the air from entering the second chamber (6). When the level of the liquid in the first chamber (5) drops below a value whereby the flotation of the float (23) is no longer possible, the latter returns downwards to the position shown in FIG. 4, the valve (16) closes again and the valve (18) opens again to thus allow the liquid present in the second chamber (6) to be evacuated externally.
Should the quantity of liquid extracted by the suction probe exceed the quantity that can be evacuated, the chamber (5) fills with liquid.
Once the level of the liquid reaches the third measuring contrivance (50), the operation of the suction pump is interrupted and the chambers (5) and (6) reach the atmospheric pressure. The valves (16) and (18) open and discharge the liquid continuously by gravity. The suction pump resumes its operation once the level of the liquid in the chamber (5) arrives at a lower level than that of the intermediate measuring contrivance (51).
The invention can undergo numerous modifications of a practical nature without in any way deviating from the conceptual framework of the invention as per the claims listed hereinafter.
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Disclosed herein is a liquid separating and evacuating device for fluid suction equipment and, in particular, for dental surgery equipment, with which it is possible to separate the air from the liquids and to continuously drain the latter without interrupting the suction.
The said device consists essentially of a cylindrical container, placed on a vertical axis, that is provided on the bottom part thereof with a draining valve. Placed inside the said container there is a horizontal partition that is divided into two superposed chambers. This partition has a valve which either allows or prevents the liquid from passing from the first chamber to the second chamber.
A float contained in the first chamber controls, by actuating a pneumatic distributor, the opening and the closing of the aforementioned valves which successively allow the liquid to pass from the first chamber to the second chamber and from the latter to the outside.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a parts exchange mechanism of a chip mounter, and particularly to techniques of exchanging parts of a chip mounter, such as a suction bit for sucking electronic parts, and a positioner for centering and positioning the electronic parts. These electronic parts are chip-shaped electronic parts such as semiconductor chips and mounted onto a printed circuit board by the chip mounter.
2. Related Art Statement
In general, there are a multiplicity of types of chip-shaped electronic parts differing in dimensions and shapes from one another. In order to mount the chip-shaped electronic parts having the multiplicity of types onto the printed circuit boards by one chip mounter, it is necessary to exchange, at least, a suction bit for sucking the chip-shaped electronic parts and a positioner for centering the chip-shaped electronic parts, in accordance with the dimensions and shapes of the electronic parts to be mounted.
To this end, in the common practice of the art, chip mounting work was temporarily suspended, and a suction bit and a positioner were changed separately by hand.
However, when there are many types of electronic parts to be mounted, it was extremely troublesome and complicated to manually carry out exchange of parts such as the suction bit and the positioner in accordance with the type of electronic parts mounted. Thus, efficiency of parts exchanging of the chip mounter were lowered, being great obstacle to automate chip mounting work from beginning to end.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a technique capable of automatically carrying out exchange of a suction bit, a positioner and the like of the chip mounter.
It is another object of the present invention to provide a technique capable of simultaneously carrying out exchange of a suction bit and a positioner of the chip mounter.
A parts exchange mechanism of a chip mounter according to the present invention is a mechanism for exchanging parts such as a suction bit and a positioner of a chip mounter, comprising:
holding means for holding parts to be exchanged on the side of the chip mounter;
receiving and delivering means for receiving the parts to be exchanged from the holding means and delivering the same thereto;
clamp means capable of clamping and releasing the parts to be exchanged; and
an actuator for causing the parts clamp means to clamp and release;
wherein: the clamp means is actuated by the operation of the actuator; and receiving and delivering of the parts to be exchanged between the holding means and the receiving and delivering means and exchange of the parts to be exchanged are automatically carried out.
Another parts exchange mechanism of a chip mounter according to the present invention is a parts exchange mechanism for exchanging a suction bit and a positioner of the chip mounter, comprising:
a suction bit holding member and a positioner holding member respectively provided on a mounter head of the chip mounter so as to hold the suction bit and the positioner, respectively;
a collet chuck for holding the suction bit, which receives the suction bit from the suction bit holding member and delivers the same thereto;
a chuck sleeve for applying a clamping force to the collet chuck or releasing the force therefrom so as to cause the collet chuck to clamp or release the suction bit;
a first rod connected to the chuck sleeve;
a first actuator for causing the first rod to move in its axial direction;
a piston member connected to the collet chuck and capable of moving in its axial direction so as to receive the positioner from the positioner holding member and deliver the same thereto while holding the positioner;
clamp pawls rocking about a pin so as to clamp or release the positioner held by the piston member;
a clamp pawl rocking means connected to the chuck sleeve, for applying a rocking force to the clamp pawls;
a post member connected to the piston member and the first actuator; and
a second actuator for causing the first actuator to operate in its axial direction.
By use of the former mechanism described above, the parts to be exchanged such as the suction bit and the positioner of the chip mounter are fully automatically exchanged without the need of hand work, so that the efficiencies of the parts exchange work and the chip mounting work can be improved.
Furthermore, by use of the latter mechanism described above, the suction bit and the positioner of the chip mounter are automatically exchanged at the same time, so that the working efficiencies can be further improved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing an embodiment of parts exchange mechanism according to the present invention; and
FIGS. 2 and 3 are front views for explaining the states of operation thereof.
DETAILED DESCRIPTION OF THE INVENTION
In this embodiment, reference numeral 1 denotes a mounter head of a chip mounter, and 2 a parts exchange mechanism.
The mounter head 1 of the chip mounter has a suction bit holding member 5 (a first holding means) for holding a suction bit 3 and a positioner holding member 6 (a second holding means) for holding a positioner 4.
Simultaneous and automatic exchange of the suction bit 3 and the positioner 4 can be carried out by the parts exchange mechanism 2 of this embodiment.
Accordingly, a parts exchange structure for the suction bit 3 and a parts exchange structure for the positioner 4 are interlockingly constructed for operation.
First, the parts exchange structure for the suction bit 3 will be described. The parts exchange structure for the suction bit 3 has: a first air cylinder 7 as being a first actuator; a first rod 9 connected and fixed to the top end of a cylinder rod 8 of the first air cylinder 7; a chuck sleeve 11 connected to the top end of the first rod 9 by means of a pin 10; and a collet chuck 12 (a clamp means) inserted into the top end portion of the chuck sleeve 11 in the vertical direction, the upper portion of the collet chuck 12 is vertically split so that the upper portion thereof opens or closes in response to the vertical movement of the chuck sleeve 11 due to a tapered type chuck construction thereof so as to clamp or release the suction bit 3 (parts to be exchanged).
On the other hand, the parts exchange structure for the positioner 4 includes: a second air cylinder 13 as being a second actuator; a second rod 15 connected and fixed to the top end of a cylinder rod 14 of the second air cylinder 13, for pushing up the first air cylinder 7 by the operation of the second air cylinder 13; plates 16 and 17 fixed to the undersurface of the first air cylinder 7; a post 19 connected and fixed to the plate PG,8 16 by means of a bolt 18; a plate 20 connected to the top end of the post 19 by means of a bolt 20a; a piston member 23 connected and fixed at the bottom end thereof to the inner periphery of the plate 20 by means of a nut 21, and connected and fixed at the top end thereof to the collet chuck 12 by means of a pin 22, extending vertically outwardly of the first rod 9, and mounted at the top surface thereof with the positioner 4 which is to be received from and delivered to the positioner holding member 6; a cylinder member 24 for guiding the vertical movement of the piston member 23; a ring 26 (a clamp pawl rocking means) connected and fixed to the chuck sleeve 11 by means of a pin 25; and four (for example) generally L-shaped clamp pawls 29 (a clamp means) adapted to rock about a pin 28 in response to the vertical movement of the ring 26 and a biasing force of a spring 27 to thereby clamp or release the positioner 4 held on the piston member 23.
In addition, a plate 30 and a post 31 are connected to the top end of the second air cylinder 13.
Action of this embodiment will hereunder be described.
First, the description is given of a case where the suction bit 3 and the positioner 4 are respectively mounted onto the suction bit holding member 5 and the positioner holding member 6 of the mounter head 1 of the chip mounter, by the parts exchange mechanism 2.
First, when the first air cylinder 7 is driven to raise the cylinder rod 8, the first rod 9 mounted on the forward end (top end) of the cylinder rod 8, the chuck sleeve 11 fixed to the first rod 9 by means of the pin 10 and the ring 26 fixed to the chuck sleeve 11 by means of the pin 25 are raised. As the ring 26 rises, the clamp pawls 29 are rotated about the pin 28 in the counterclock-wise direction against the biasing force of the spring 27, the upper end potions of clamp pawls are opened as indicated by arrows, and the positioner 4 mounted on the top surface of the piston member 23 is released.
On the other hand, as the chuck sleeve 11 rises, the upper portion of the collet chuck 12 flares resiliently to thereby release the suction bit 3.
Subsequently, the mounter head 1 not holding the positioner 4 by means of the holding members 5 and 6 is positioned upwardly of the suction bit 3 and the positioner 4 which were released as described above.
In this state, when the second air cylinder 13 is driven to raise the cylinder rod 14, the second rod 15 fixed to the cylinder rod 14 rises to push up the undersurface of the first cylinder 7. Since the first air cylinder 7, the plate 16, the post 19, the plate 20 and the piston member 23 are fastened to one another, the piston member 23 rises while being guided by the inside diameter of the cylinder member 24 as the first air cylinder 7 is pushed up.
As a result, the positioner 4 mounted on the top surface of the piston member 23 and the suction bit 3 inserted into the collet chuck 12 fixed to the piston member 23 by means of the pin 22 are raised together with the piston member 23, delivered to the suction bit holding member 5 and the positioner holding member 6 which are provided on the mounter head 1, respectively, and held thereby.
Subsequently, when the second air cylinder 13 is driven to draw in the cylinder rod 14, the second rod 15 fixed to the cylinder rod 14 is lowered to pull down the plate 17.
Since the plate 16, the plate 17, the post 19, the plate 20 and the piston member 23 are fastened to one another, the piston member 23 and the collet chuck 12 fixed to the piston member 23 by means of the pin 22 are pulled down as the plate 17 is lowered.
At this time, since the clamp pawls 29 and the collet chuck 12 are still in the released states, the suction bit 3 and the positioner 4 remain in the mounter head 1 while being held by the respective holding members 5 and 6. With this operation, mounting of the suction bit 3 and the positioner 4 onto the mounter head 1 is carried out fully automatically and simultaneously.
Next, the description is given of a case where the suction bit 3 and the positioner 4 are simultaneously and automatically removed from the mounter head 1.
First, the mounter head 1 is positioned upwardly of the piston member 23 being in a state where the suction bit 3 and the positioner 4 are not mounted or held thereon.
After this positioning, the mounter head 1 is driven by a driving means, not shown, to bring the suction bit 3 held by the suction bit holding member 5 into a lowered state, and to bring the positioner 4 held by the positioner holding member 6 into a released state.
In this state, when the second air cylinder 13 of the parts exchange mechanism 2 is driven to raise the cylinder rod 14 thereof, the second rod 15 connected and fixed to the cylinder rod 14 is raised to push up the undersurface of the first air cylinder 7.
Since the first air cylinder 7, the plate 16, the post 19, the plate 20 and the piston member 23 are fastened to one another, the piston member 23 rises while being guided by the inside diameter of the cylinder member 24 as the first air cylinder 7 is pushed up.
By this rise of the piston member 23, the piston member 23 receives the positioner at the upper surface thereof, while, the collet chuck 12 connected and fixed to the piston member 23 by means of the pin 22 also rises together with the piston member 23 and the inner diametral surface of the collet chuck 12 receives the outer shape of the suction bit 3.
Thereafter, when the first air cylinder 7 is driven to draw in the cylinder rod 8 thereof, the first rod 9 fixed to the top end of the cylinder rod 8, the chuck sleeve 11 connected and fixed to the first rod 9 by means of the pin 10 and the ring 26 connected and fixed to the chuck sleeve 11 by means of the pin 25 are lowered.
As the ring 26 is lowered, the clamp pawls 29 are rotated about the pin 28 in the clock-wise direction by the biasing force of the spring 27 to clamp the positioner 4 mounted on the top surface of the piston member 23 as shown in FIG. 1.
At the same time as this, the chuck sleeve 11 is lowered and the collet chuck 12 is closed due to the tapered type chuck construction thereof to clamp the suction bit 3 which has been received in the inside diameter of the collet chuck 12 from outside.
Subsequently, when the second air cylinder 13 is driven to draw in the cylinder rod 14 thereof, the second rod 15 connected and fixed to the cylinder rod 14 is lowered to pull down the plate 17.
Since the plate 16, the plate 17, the post 19, the plate 20 and the piston member 23 are fastened to one another, the piston member 23 and the collet chuck 12 connected and fixed to the piston member 23 by means of the pin 22 are lowered as the plate 17 is pulled down.
At this time, since the collet chuck 12 and the clamp pawls 29 are clamping the suction bit 3 and the positioner 4, respectively, the suction bit 3 and the positioner 4 are held in the inside diameter of the collet chuck 12 and on the top surface of the piston member 23, respectively, and simultaneously and automatically removed from the suction bit holding member 5 and the positioner holding member 6 of the mounter head 1, respectively.
With this operation, removal of the suction bit 3 and the positioner 4 from the mounter head 1 is automatically and simultaneously completed.
Accordingly, in this embodiment, the suction bit 3 and the positioner 4 of the chip mounter can be simultaneously and fully automatically mounted onto the holding members 5 and 6 and removed therefrom by use of the parts exchange mechanism 2, so that the parts exchange can be carried out highly efficiently for a very short time.
Although the parts exchange mechanism 2 in this embodiment is an automatic parts exchange mechanism having multiple functions, the component parts thereof are intensively arranged in straight and compact manner in the longitudinal direction, so that the parts exchange mechanism is advantageous in terms of space efficiency. Moreover, the parts exchange mechanism as a whole constitutes an independent station, so that additional installations of a plurality of parts exchange mechanisms can be easily carried out.
Incidentally, the present invention is not limited to the above embodiment, and various other modifications can be adopted.
Furthermore, the present invention may be applied to the exchange of the component parts of the chip mounter other than the suction bit and the positioner.
According to the present invention, the following excellent functional effects can be achieved.
(1) Component parts such as the suction bit and the positioner of a chip mounter can be fully automatically exchanged, so that there is no need of carrying out parts exchange by hand work while stopping operation of the chip mounter, thus considerably improving the efficiency of parts exchange.
(2) The suction bit and the positioner are exchanged simultaneously, so that the efficiency of parts exchange working can be further improved and parts exchange can be carried out for a very short time.
(3) According to the above-described items (1) and (2), the chip mounting work can be carried out automatically from beginning to end.
(4) Furthermore, according to the above-described items (1) and (2), electronic parts such as the semiconductor chip parts having the multiplicity of types which differ in dimensions and shapes can be mounted onto the printed circuit board by one chip mounter at high efficiency and with safety.
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A parts exchange mechanism of a chip mounter, capable of automatically exchanging parts such as a suction bit for sucking chip-shaped electronic parts to be mounted onto a printed circuit board, and a positioner for centering the same. The part exchange mechanism comprises: holding means for holding the parts to be exchanged on the side of the chip mounter; receiving and delivering means for receiving the parts from the holding means and delivering same thereto; clamp means capable of clamping and releasing the parts; and an actuator for causing the clamp means to clamp and release. A parts exchange mechanism capable of automatically and simultaneously exchanging plurality of parts of a chip mounted is also provided.
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The present application is a CON of U.S. patent application Ser. No. 10/893,328, filed Jul. 19, 2004, now U.S. Pat. No. 7,317,496 which is a CON of U.S. patent application Ser. No. 10/427,139, filed May. 02, 2003, now U.S. Pat. No. 6,791,630, which is a DIV of U.S. patent application Ser. No. 09/829,818, filed Apr. 10, 2001, now U.S. Pat. No. 6,580,473, which is a DIV of U.S. patent application Ser. No. 08/884,607, filed Jun. 30, 1997, now U.S. Pat. No. 6,262,784, which is a CIP of U.S. patent application Ser. No. 08/602,104, filed Feb. 23, 1996, now U.S. Pat. No. 5,696,566, which is a DIV of U.S. patent application Ser. No. 08/070,717, filed Jun. 1, 1993, now U.S. Pat. No. 5,517,341.
FIELD OF THE INVENTION
The present invention relates to display devices and methods of forming display devices, and more particularly to liquid crystal display devices and methods of forming liquid crystal display devices.
BACKGROUND OF THE INVENTION
In order to minimize the space required by display devices, research into the development of various flat panel display devices such as LCD display devices, plasma display panels (PDP) and electro-luminescence displays (EL), has been undertaken to displace larger cathode-ray tube displays (CRT) as the most commonly used display devices. Particularly, in the case of LCD display devices, liquid crystal technology has been explored because the optical characteristics of liquid crystal material can be controlled in response to changes in electric fields applied thereto. As will be understood by those skilled in the art, a thin film transistor liquid crystal display (TFT LCD) typically uses a thin film transistor as a switching device and the electrical-optical effect of liquid crystal molecules to display data visually.
At present, the dominant methods for fabricating liquid crystal display devices and panels are typically methods based on amorphous silicon (a-Si) thin film transistor technologies. Using these technologies, high quality image displays of substantial size can be fabricated using low temperature processes. As will be understood by those skilled in the art, conventional LCD devices typically include a transparent (e.g., glass) substrate with an array of thin film transistors thereon, pixel electrodes, orthogonal gate and data lines, a color filter substrate and liquid crystal material between the transparent substrate and color filter substrate. The use of a-Si TFT technology typically also requires the use of separate peripheral integrated circuitry to drive the gates and sources (i.e., data inputs) of the TFTs in the array. In particular, gate driving signals from a gate driving integrated circuit are typically transmitted to the gate electrodes of TFTs in respective rows and data driving signals from a data driving integrated circuit are typically transmitted to the source electrodes of TFTs in respective columns. A display is typically composed of a TFT substrate in which a plurality of liquid crystal pixels are formed. Each pixel typically has at least one TFT and a pixel electrode coupled to the drain of the respective TFT. Accordingly, the application of a gate driving signal to the gate of a TFT will electrically connect the pixel electrode of a respective TFT to the data line connected thereto.
Referring now to FIGS. 1-3 , an active matrix substrate of a conventional TFT LCD with a light blocking film will be described. This and other TFT LCDs are more fully described in U.S. Pat. No. 5,426,523 to Shimada et al. In particular, FIG. 1 is a plan view showing a conventional active matrix display device. FIG. 2 is a cross-sectional view of the active matrix display device of FIG. 1 , taken along line A-A′ and FIG. 3 is a cross-sectional view of the active matrix display device of FIG. 1 , taken along line B-B′. As illustrated by FIG. 1 , a gate line 130 is formed in a horizontal direction, and a data line 150 crosses the gate line 130 . A light blocking film 8 , with a width larger than that of the data line 150 , is formed on each data line 150 . Each of the side excess portions over the data line 150 in the transverse direction is set to a length “d”. In each region defined by the gate and data lines, a pixel electrode 7 is formed so that both sides of the pixel electrode 7 overlap the neighboring blocking films and data lines by a constant length. In each pixel region, a TFT is formed. Specifically, the region of a silicon film 110 under the branch of the gate line 130 forms a gate of the TFT, the region of the silicon film 110 connected to the data line 150 by way of a contact hole 4 a forms a source of the TFT, and the region of the silicon film 110 connected to the pixel electrode 7 by way of a contact hole 4 b forms a drain of the TFT. If a turn-on voltage is applied to the gate line 130 , a conduction path between source and drain becomes active due to the ON state of the TFT, and, therefore a video signal from the data line 150 can be transmitted to the pixel electrode 7 via the silicon film 110 .
Referring now to FIG. 2 , a silicon film 110 is formed on a transparent substrate 100 , and serves as a source electrode, a drain electrode and a semiconductor active layer of the TFT. A gate insulating film 120 is formed on the silicon film 110 and the transparent substrate 100 so as to cover the entire surface. On a certain region of the gate insulating film 120 , a gate electrode 130 is formed. Moreover, an insulating film 140 is formed on the entire surface of the gate electrode 130 and the gate insulating film 120 . A contact hole 4 a is formed through the gate insulating film 120 and the insulating film 140 . On the insulating film 140 , the data line 150 is formed and connected to the silicon film 110 via the contact hole 4 a.
On the entire surface of the insulating film 140 and the data line 150 , a passivation film 160 is formed, and a contact hole 4 b is formed through the gate insulating film 120 , the insulating film 140 and the passivation film 160 . A pixel electrode 7 , made of an indium-tin-oxide (ITO) film, is formed on the passivation film 160 and connected to the silicon film 110 via the contact hole 4 b . A video signal received from the data line 150 passes through the silicon film 110 via the contact hole 4 a , and, then, is transmitted to the ITO pixel electrode 7 via the contact hole 4 b . The TFT with such a structure where the gate electrode 130 is located on the semiconductor layer is called a top gate type TFT.
A cross-sectional structure of the prior active matrix substrate coupled with a liquid crystal layer and a counter substrate will now be described with reference to FIG. 3 . Here, a gate insulating film 120 is formed on a transparent substrate 100 , and a data line 150 is formed thereon. A passivation film 160 is formed on the entire film of the gate insulating film 120 and the data line 150 , and a light blocking film 8 is formed on the passivation film so as to cover a certain region of the passivation film over the data line 150 . An insulating film 180 is formed on the entire surface of the light blocking film 8 and the passivation film 160 , and an ITO pixel electrode 7 is formed thereon. In the above mentioned structure of the prior active matrix substrate, the data line 150 has a thickness of 500 nm, and is usually formed of aluminum (Al). The passivation film 160 is formed of silicon oxide (SiOx) having a thickness of 400 nm. Furthermore, the light blocking film 8 having a thickness of 100 nm is formed of the same material as the data line 150 , and each of the lengths “d” of the side excess portions of the light blocking film 8 over the data line 150 in the transverse direction, is set to be 5 μm.
A counter substrate 200 , including a transparent counter electrode 210 formed on the surface thereof, is attached to the active matrix substrate. Into a space between the two substrates, liquid crystal is injected to form the liquid crystal layer 190 , and the thickness of the liquid crystal layer 190 is set to be about 5 μm. Here, even though abnormal light leakage occurs due to the orientation disorder of the liquid crystal molecules in the edge regions of the data line 150 (caused by a step of the data line 150 ), the light leakage can be blocked considerably since the light blocking film 8 is broader than the data line 150 and is formed to cover the data line 150 . In these circumstances, the orientation disorder of the liquid crystal molecules by a step of the light blocking film 8 can be negligible, since the thickness of the light blocking film 8 is very small than that of the data line 150 .
However, some light leakage still remains due to the considerable step of the data line 150 . Especially, in a normally white mode display, the vicinity of the step of the data line 150 is not absolutely black even when a voltage is applied to the liquid crystal for a black display. Thus, the contrast of the display apparatus is degraded. In addition, the opening ratio of the liquid crystal display apparatus is made smaller since the light blocking film 8 is formed to exceed 5 μm at its side portions over the data line 150 and thus covers the pixel electrode 7 with its excess regions.
In the illustrated display device, the light blocking film 8 is located between the pixel electrode 7 and the data line 150 while overlapping one another. Accordingly, the capacitive coupling between the pixel electrode 7 and the data line 150 increases because the light blocking film 8 serves as an intermediate conductive layer. Moreover, the fabrication of this structure where the light blocking film 8 is formed on the data line 150 increases manufacturing cost since it requires additional processes such as metal deposition and etching.
Thus, notwithstanding the above described prior art active matrix liquid crystal display devices, there continues to be a need for improved liquid crystal display devices which have high contrast and opening ratios and are less susceptible to light leakage caused by disordered or misaligned liquid crystal molecules.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide improved liquid crystal display (LCD) devices and methods of forming same.
It is another object of the present invention to provide liquid crystal display devices having improved opening ratios and methods of forming same.
It is a further object of the present invention to provide liquid crystal display devices having improved contrast ratios and methods of forming same.
It is still a further object of the present invention to provide liquid crystal display devices having light blocking lines which do not contribute to parasitic capacitive coupling between data lines and pixel electrodes, and methods of forming same.
These and other objects, advantages and features of the present invention are provided by liquid crystal display devices which having pixel electrodes, data lines and gate lines and utilize light blocking lines to improve display contrast ratios yet position the light blocking lines on the same level of metallization as the gate lines to thereby limit parasitic capacitive coupling between the data lines and the pixel electrodes. In addition, the light blocking lines are positioned on only one side of the data lines so that improvements in the display's opening ratio can also be achieved.
In particular, according to the present invention, liquid crystal display devices comprise an array of liquid crystal display cells (e.g., TFT display cells) and a plurality of light blocking lines to improve the contrast ratios of the display devices. The light blocking lines are preferably patterned so that no overlap occurs between a display's data lines and the light blocking lines. The elimination of overlap reduces the step height in the display's pixel electrodes and thereby reduces the extent of disclination of the liquid crystal molecules in the liquid crystal material extending opposite the pixel electrodes. The light blocking lines are also preferably patterned beneath the display's data lines so that parasitic capacitive coupling between the data lines and the pixel electrodes is reduced. Moreover, although the light blocking lines are formed parallel to the data lines, they are preferably formed on only one side of the data lines so that improved opening ratios can be achieved. The light blocking lines are also preferably formed with beveled edges so that the step height in the display's pixel electrodes can be reduced even further. Thus, the light blocking lines are formed to compensate for light leakage (which may occur because of the presence of parasitic electric fields between a display's data lines and pixel electrodes during operation) yet still maintain the degree of disclination of the liquid crystal molecules at a low level by allowing the pixel electrodes to be formed with reduced step height.
According to one embodiment of the present invention, a liquid crystal display device comprises a transparent substrate having a face thereon, and first and second display cells on the substrate. The first display cell contains a first pixel electrode and has a control input (e.g., gate electrode of a TFT) electrically coupled to a first gate line. The second display cell: contains a second pixel electrode and a control input electrically coupled to a second gate line. A first light blocking line is also provided on the substrate. The first light blocking line is preferably electrically coupled to the first gate line by patterning the first gate line and the first light blocking line using the same level of metallization. A first data line is also provided on the substrate. According to a preferred aspect of the present invention, the first data line overlaps the first and second pixel electrodes by not the first light blocking line. The first data line is also preferably formed at a higher level of metallization relative to the first light blocking line so that, among other things, parasitic capacitive coupling between the first data line and the first and second pixel electrodes can be maintained at a relatively low level.
According to another embodiment of the present invention, a liquid crystal display device comprises an array of liquid crystal display cells on a transparent substrate, arranged as a plurality of rows and columns of display cells. A plurality of data lines are also provided on the substrate so that each data line is disposed between adjacent columns of display cells. A plurality of ladder-shaped electrodes are also provided on the substrate and each of the ladder-shaped electrodes is disposed opposite a row of display cells so that the pixel electrodes in each row of display cells overlap a respective ladder-shaped electrode. The ladder-shaped electrodes are also preferably formed with beveled edges to improve the planar uniformity of the subsequently formed pixel electrodes and reduce the extent of disclination between the liquid crystal molecules in the liquid crystal material extending opposite the pixel electrodes.
The present invention also includes methods of forming liquid crystal display devices having improved opening and contrast ratios. In particular, according to yet another embodiment of the present invention, a method of forming a liquid crystal display device (e.g., active matrix display) includes the steps of forming a first conductive layer (e.g., aluminum) on a face of a transparent substrate and then patterning the first conductive layer to define a ladder-shaped electrode having first and second side electrodes and a plurality of rungs electrically interconnecting the first and second side electrodes. A first electrically insulating layer (e.g., SiO 2 ) is then formed on the ladder-shaped electrode. Next, a layer of amorphous silicon (a-Si) is formed on the first electrically insulating layer. The layer of amorphous silicon is then patterned to define an amorphous silicon active region extending opposite a portion of the first side electrode. A second conductive layer is then formed on the first electrically insulating layer and amorphous silicon active region. The second conductive layer is then patterned into a data line and a drain electrode so that the data line and drain electrode contact first and second portions of the amorphous silicon active region, respectively. A second electrically insulating layer (e.g., Si 3 N 4 ) is then formed on the patterned second conductive layer and then patterned to expose a portion of the drain electrode. A layer of indium-tin-oxide (ITO) is then deposited and patterned to define a pixel electrode which is electrically connected to the exposed portion of the drain electrode.
Thus, the present invention provides for liquid crystal display devices having improved contrast ratios by incorporating light blocking lines therein. The light blocking lines are also patterned so that any step height in the display's pixel electrodes is maintained at a low level so that the degree of disclination in the liquid crystal material is reduced. This is achieved by patterning the light blocking lines so that they do not overlap the display's data lines. In addition, the light blocking lines are preferably positioned on only one side of the data lines so that improved opening ratios can be achieved. The parasitic loading capacitance between the data lines and pixel electrodes can also be improved by patterning the light blocking lines below the data lines, using the same level of metallization as used to form the gate lines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a layout schematic view or a liquid crystal display device according to the prior art.
FIG. 2 is a cross-sectional view of the liquid crystal display device of FIG. 1 , taken along line A-A′.
FIG. 3 is a cross-sectional view of the liquid crystal display device of FIG. 1 , taken along line B-B′.
FIG. 4 is a layout schematic view of an active matrix liquid crystal display device according to the present invention.
FIG. 5 is a cross-sectional view of a first embodiment of the device of FIG. 4 , taken along line C-C′.
FIG. 6 is a cross-sectional view of a second embodiment of the device of FIG. 4 , taken along line C-C′.
FIG. 7 is a cross-sectional view of a third embodiment of the device of FIG. 4 , taken along line C-C′.
FIG. 8 is a cross-sectional view of an embodiment of the device of FIG. 4 , taken along line D-D′.
FIG. 9 is a cross-sectional view of another embodiment of the device of FIG. 4 , taken along line D-D′.
FIG. 10 is an electrical schematic of an active matrix liquid crystal display device according to an embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be 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 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. Like numbers refer to like elements throughout.
Referring to FIGS. 4 and 10 , layout and electrical schematic diagrams of an active matrix liquid crystal display device according to the present invention will now be described. In particular, an active matrix liquid crystal display device is provided which comprises a two-dimensional array of thin-film transistor (TFT) liquid crystal display cells arranged as a plurality of columns of display cells and a plurality of rows of display cells. As illustrated, each column of display cells is defined between adjacent data lines 150 (e.g., D j−2 , D j−1 , . . . , D j+1 ) and each row of display cells is defined between adjacent gate lines 130 a (e.g., G i−2 , G i−1 , . . . , G i+2 ). Each display cell may comprise an amorphous silicon (a-Si) thin-film field effect transistor (TFT) having a source region electrically coupled to a corresponding data line 150 via an orthogonal data line extension, a gate electrically coupled to a corresponding gate line 130 a and a drain region electrically coupled to a respective pixel electrode 7 preferably formed of a transparent material such as indium-tin-oxide (ITO). Each display cell also preferably comprises a storage capacitor (C S ). As will be understood by those skilled in the art, the value of the storage capacitor is a function of, among other things, the area of overlap between a pixel electrode 7 and an electrode coupled to an adjacent lower order gate line. As best illustrated by FIG. 4 , the value of the storage capacitor is a function of the area of overlap between each pixel electrode 7 and an underlying ladder-shaped electrode which, as described more fully hereinbelow, is comprised of a gate line 130 a , a light blocking line 9 and a storage electrode line 130 b . A liquid crystal capacitor C LC is also defined by each cell as the capacitance between a pixel electrode on a lower TFT substrate and a counter electrode 210 on an upper counter substrate 200 . As illustrated, the counter electrode 210 may be biased to a common potential (V com ).
Referring again to FIG. 4 , the data lines 150 are preferably patterned as a plurality of parallel lines of metallization and each row of display cells is defined opposite a respective ladder-shaped electrode which is comprised of a plurality of light blocking lines 9 at the rungs of the ladder-shaped electrode, a gate line 130 a and a storage electrode line 130 b which extends parallel to the gate line 130 a . According to a preferred aspect of the present invention, each light blocking line 9 is defined in parallel with a corresponding data line 150 , however, these lines are spaced laterally from each other so there is no overlap between them. This reduces the extent of any parasitic capacitive coupling between the data lines 150 and the light blocking lines 9 . Moreover, because each light blocking line 9 is located on only one side of a respective data line 150 and pixel electrode 7 , in contrast to the prior art active matrix substrates where both sides of a pixel electrode extend opposite a light blocking line, the opening ratio of the liquid crystal display device is increased. As described more fully hereinbelow, the location of each light blocking line 9 relative to a respective pixel electrode 7 is a function of the angle of orientation of the liquid crystal molecules in the liquid crystal material which separates the lower TFT substrate 100 from the upper counter substrate 200 . As illustrated, the light blocking lines 9 are located on the left side of the pixel electrodes to correspond to the angle of orientation of the liquid crystal molecules 190 ′ illustrated by FIGS. 5-7 .
Referring now to FIGS. 5-8 , cross-sectional views of various embodiments of the device of FIG. 4 are illustrated. In particular, the display device of FIG. 4 may be formed by forming a first conductive layer (e.g., aluminum, titanium, tungsten and alloys thereof) on a face of a transparent substrate 100 and then patterning the first conductive layer as a ladder-shaped electrode comprised of a plurality of light blocking lines 9 (at the rungs of the ladder-shaped electrode), a gate line 130 a and storage electrode line 130 b . In FIG. 8 , the illustrated cross-sections of the gate line 130 a and the storage electrode line 130 b are part of adjacent ladder-shaped electrodes. The first conductive layer may be formed to have a thickness of about 2,000 Å. After the first conductive layer has been patterned to define a plurality of ladder-shaped electrodes, the edges of the ladder-shaped electrodes are beveled, using conventional techniques, to reduce the abruptness of their cross-sectional profile to subsequently formed layers. A first electrically insulating layer 120 (e.g., SiO 2 ) is then formed on the patterned first conductive layer and face of the transparent substrate 100 , as illustrated.
Next, a layer of amorphous silicon (a-Si) is formed on the first electrically insulating layer 120 and then patterned to define a plurality of amorphous silicon active regions 110 of subsequently formed TFTs. Then, a blanket second electrically conductive layer, which may have thickness of less than about 2,000 Å, is formed on the first electrically insulating layer 120 and active regions 110 . The second electrically conductive layer is then patterned using conventional techniques to define (i) a plurality of parallel data lines 150 which have orthogonal extensions in ohmic contact with source region portions of the active regions 110 , and (ii) a plurality of drain electrodes 170 in ohmic contact with drain region portions of the active regions 110 . A second electrically insulating region 160 is then formed on the patterned second electrically conductive layer. This second electrically insulating layer 160 may comprise an inorganic passivation layer of silicon nitride (Si 3 N 4 ) having a thickness of less than about 4,000 Å, for example. The second electrically insulating layer 160 is then patterned to define a plurality of openings therein which expose respective drain electrodes 170 of the display cells. An optically transparent layer of indium-tin-oxide is then formed on the second electrically insulating layer 160 and patterned to define a plurality of pixel electrodes 7 . As illustrated, the opposing ends of adjacent pixel electrodes preferably overlap opposing edges of each data line 150 .
As best illustrated by FIG. 5 , a upper counter substrate 200 containing a counter electrode 210 is then mounted in spaced relation opposite the lower TFT substrate 100 . As will be understood by those skilled in the art, liquid crystal material is then injected into the space between the lower and upper substrates to define a liquid crystal material layer 190 having a pre-tilt angle. As will be understood by those skilled in the art, the tilt of the liquid crystal molecules 190 ′ in the liquid crystal material layer 190 is influenced by the magnitude of the vertical electric field which can be established between each pixel electrode 7 and the counter electrode 210 . However, near the vicinity of each data line 150 , the tilt orientations of the liquid crystal molecules 190 ′ in the liquid crystal material 190 are altered or scattered by stray and horizontal electric fields in the gap between adjacent pixel electrodes 7 . As illustrated, the stray electric fields may be sufficient to switch the pre-tilt orientation of the liquid crystal molecules 190 ′ to an opposite direction in what is commonly referred to as a “disclination region” illustrated as region d 1 . Unfortunately, the transmission of light through the disclination region is typically nonuniform and in a normally white display, light may be allowed to pass through the disclination region even when the pixel electrodes 7 are biased to provide a black display image. When this occurs, the contrast ratio of the display is adversely affected. However, according to the present invention, the light blocking lines 9 are designed to block light which otherwise would be pass through the transparent substrate 100 (from a backlight) and into the disclination region. Here, the light blocking lines 9 are typically patterned to be wider than the disclination region d 1 . Moreover, because the width of the disclination region d 1 typically increases with any increase in step height associated with the pixel electrodes 7 , the light blocking lines 9 are spaced laterally from the data lines 150 so there is no overlap therebetween which might increase the step height of the pixel electrodes 7 (and also increase the magnitude of any parasitic load capacitance between the data lines 150 ). Finally, because the light blocking lines 9 are positioned along only one side of the pixel electrode 7 , the opening ratio of the display device may be increased.
Referring now specifically to FIG. 6 , the width of the disclination region (shown as d 2 ) may be reduced even further by improving the planar uniformity of the pixel electrodes 7 . According to another preferred aspect of the present invention, this reduction in the width of the disclination region can be achieved by forming an organic electrically insulating/passivation layer 220 on the inorganic insulating layer 160 . The organic insulating layer 220 preferably comprises a layer of polyimide or an acrylic resin having a smooth upper surface and a thickness in a range between about 5,000 and 7,000 Å. In particular, the organic insulating layer 220 is made sufficiently thick to offset step-height variations in the inorganic insulating layer 160 . The organic insulating layer 220 may also be planarized using conventional techniques to define a planarized upper surface on which the pixel electrodes 7 can be formed.
Referring now specifically to FIG. 7 , the above-described method of forming a liquid crystal display device may be simplified by omitting the step of forming an inorganic insulating layer 160 which typically involves a chemical vapor deposition step. However, to compensate for the missing inorganic insulating layer 160 , an organic insulating layer 220 may be formed to have a thickness in a range between about 15,000 and 35,000 Å, however, thicker insulating layer 220 may also be used. This organic insulating layer 220 may also be planarized so that the pixel electrodes 7 have reduced step height. As will be understood by those skilled in the art, increasing the thickness of the organic insulating layer 220 increases the vertical distance between the data lines 150 and the pixel electrodes 7 and thereby reduces the magnitudes of the stray electric fields adjacent the spaces between the pixel electrodes 7 . As described above, this reduction in field strength and step height reduces the width of the disclination region so that d 3 <d 2 <d 1 . Accordingly, the widths of the light blocking lines 9 may also be decreased as the vertical spacing between the data lines 150 and pixel electrodes 7 is increased. Thus, increased opening ratios may be achieved by increasing the thickness of the passivation layer(s) disposed between the data lines 150 and pixel electrodes 7 .
FIGS. 8 and 9 also illustrated two examples for limiting light leakage in the upper and lower sides of each pixel. The two figures are cross-sectional views of the device of FIG. 4 , taken along the line D-D′. The view of FIG. 8 corresponds to an etch back type amorphous silicon LCD apparatus, and the view in FIG. 9 corresponds to an etch stopper type amorphous silicon LCD apparatus. As shown in FIG. 8 , an organic black matrix layer 300 is formed to cover the end portions of the gate lines 130 a and storage electrode lines 130 b . The organic black matrix 300 may have a thickness of about 8,000 Å or more for a higher luminous intensity. Even though the step of the black matrix 300 may raise the orientation disorder of the liquid crystal molecules 190 ′ due to its thickness, the gate lines 130 a and storage electrode lines 130 b can effectively block the leakage of light which may be caused by step height of the black matrix 300 layer.
Referring now to FIG. 9 , a black matrix layer 230 containing chromium is formed on the counter substrate 200 . In this embodiment, the light rays reflected on the black matrix 230 may be transmitted to the channel region 10 of the TFT in the active matrix substrate, and thus light leakage can occur since the light rays produce an induced current in the channel region. However, since the amorphous silicon film layer 110 is formed very thin in the etch stopper type TFT, this light leakage can be considerably reduced.
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 purposes of limitation, the scope of the invention being set forth in the following claims.
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Active matrix display devices having improved opening and contrast ratios utilize light blocking lines to improve display contrast ratios yet position the light blocking lines on the same level of metallization as the gate lines to thereby limit parasitic capacitive coupling between the data lines and the pixel electrodes. The light blocking lines are also positioned on only one side of the data lines so that improvements in the display's opening ratio can also be achieved. The light blocking lines are preferably patterned so that no overlap occurs between a display's data lines and the light blocking lines. The elimination of overlap reduces the step height in the display's pixel electrodes and thereby reduces the extent of disclination of the liquid crystal molecules in the liquid crystal material extending opposite the pixel electrodes. The light blocking lines are also preferably patterned beneath the display's data lines so that parasitic capacitive coupling between the data lines and the pixel electrodes is reduced. The light blocking lines are also preferably formed with beveled edges so that the step height in the display's pixel electrodes can be reduced even further.
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BACKGROUND OF THE INVENTION
Approximately thirty percent of the body protein of mammals is comprised of collagen, a long rod-like polypeptide containing three parallel chains of coiled-coil structure with a molecular weight of about 300,000. Collagen existing in skin, cartilage, bone and tendon is composed of two α1 chains and one α2 chain of roughly one thousand amino acids each. The α1 sequence is completely known and substantial sequences of the α2 chain have been elucidated.
Collagenase effects an ultra-specific cleavage of collagen at a site one quarter the length of the molecule from the C-terminus in each of the three chains.
Collagenase is produced by rheumatoid synovial cells at a rate higher than it is produced by normal cells and the destructive events of rheumatoid arthritis can be correlated with the generation of collagenase. Collagenase has also been found to be involved in disease states resulting in tissue destruction of the stomach, eye, middle ear, peridontal membranes and skin. The administration of a collagenase inhibitor to prevent tissue destruction is an indicated method of treatment for disease states involving proteolytic destruction of collagen.
Collagenase is a metallo enzyme of molecular weight about 40,000 with a requirement of zinc. The enzyme is known to be inhibited by chelating agents such as ethylenediaminetetraacetic acid, o-phenanthroline, penicillamine and disulfide reducing agents such as cysteine and dithiothreitol as well as a number of poorly characterized naturally occurring substances.
DESCRIPTION OF THE INVENTION
In accordance with this invention there is provided a group of polypeptides which inhibit the activity of the enzyme collagenase. The polypeptides of this invention present the structural formula:
X--R.sub.1 --R.sub.2 --[R.sub.3 ].sub.n --NH.sub.2
in which
X is hydrogen, alkanoyl of 2 to 6 carbon atoms, cycloalkylcarbonyl of 6 to 8 carbon atoms or alkoxycarbonyl of 2 to 6 carbon atoms;
R 1 is Cys-, 3-mercapto-Val-, p-Glu-Cys-, p-Glu-3-mercapto-Val- or Pro-Gln-Gly-;
R 2 is Leu-, Ile- or Val-;
R 3 is Ala-, Ala-Gly- or Ala-Gly-Arg-; and
n is 0 or 1;
or a pharmaceutically acceptable salt thereof.
The pharmaceutically acceptable salts of the polypeptides of this invention include salts derived from either organic or inorganic acids such as acetic, lactic, succinic, benzoic, salicylic, methanesulfonic, toluenesulfonic, hydrochloric, sulfuric or phosphoric acid, and the like. Desired salts may be produced from other salts via conventional treatment with ion exchange resins. The N-terminal acyl groups depicted as X in the structural formula, supra, are preferably alkanoyl or cycloalkanoyl moieties as defined and more preferably either the acetyl or cyclopentylcarbonyl groups.
The compounds of this invention are produced by conventional solution phase techniques or solid phase techniques employing a benzhydrylamine polystyrene resin support. Thus, the individual amino acids or preformed di- or tri-peptides necessary for the formation of the desired polypeptide or their activated derivatives are condensed with formation of carbamide (--CONH--) bondings in the desired order of succession while temporarily protecting any reactive group which could undesirably enter into the condensation reaction. In the case of cysteine and penicillamine, the side chain mercapto protecting group may be acetamidomethyl, trityl, carbamoyl, thioethyl, thiotertiarybutyl or preferably p-methoxybenzyl. For arginine, the protecting groups may be nitro, benzyloxycarbonyl, adamantyloxycarbonyl, tert-butyloxycarbonyl or preferably the tosyl group. The applicable α-amino protecting groups are those well known to the art or preferably tert-butyloxycarbonyl.
The inhibitory effect of the compounds of this invention toward collagenase was determined following the procedure of Sellers et al., Biochem. J. 167, 353-360 (1977) whereby the 2 mM of the inhibitor being tested is incubated at 35° C. for from 5 to 18 hours (depending upon the potency of the collagenase) with collagen and collagenase (buffered with Tris®--CaCl 2 ; pH 7.4). The collagen is acetyl 14 C collagen. The samples are centrifuged and an aliquot removed for assay on a scintillation counter. Because native collagen forms insoluble fibrils under the test conditions, the supernatant liquid contains radioactivity as a measure of hydrolysis. The collagenase activity in the presence of 2 mM inhibitor is compared to activity in a control devoid of inhibitor and the results reported as percent inhibition of collagenase activity. Each of the compounds of this invention have been established as active collagenase inhibitors by the test procedure.
Thus, the compounds of this invention are useful in the treatment of disease states involving excessive collagen destruction by collagenase such as rheumatoid arthritis and diseases evidenced by tissue destruction of the stomach, eye, middle ear, peridontal membranes, skin. The dosage of the collagenase inhibitors of this invention will vary with the mode of administration (oral, parenteral, topical, intramuscular, etc.) and the condition of the specific patient under treatment. Proper dosing may be readily established by initial administration of small amounts of the inhibitor, ca. 100 μg/kg. followed by increased doses until the optimum effect is achieved in a specific human or non-human mammalian patient. When sustained release treatment is desired, the polypeptides may be placed in conventional depot dosage forms such as a Silastic® capsule or slow release pellet formulations conventional to the art.
The following examples illustrate the preparation of typical representative compounds of the invention. After each preparative example, the percent inhibition of collagenase activity at the 2 mM level of inhibition in accordance with the previously described standart testing procedure is provided.
EXAMPLE 1
H-L-Cys-L-Ile-NH 2
2.05 g (6 meq) of t-Boc-s-p-methoxybenzyl-L-cysteine and 973 mg (6 meq) of carbonyl diimidazole were reacted 2.5 hr. at ambient temperature in 10 ml of tetrahydrofuran. L-Isoleucine amide.HCl (1.1 g) in DMF containing 0.86 ml of triethylamine was added to the above at 0° C. and reacted over 72 hours allowing icebath to melt. The reaction mixture was evaporated under reduced pressure (<30° C.) and the residue dissolved in ethyl acetate (EtOCa)/H 2 O and filtered. The phases were separated and the EtOAc layer was extracted with 5% KHSO 4 , saturated KHCO 3 and dried over Na 2 SO 4 . The drying agent was removed was removed by filtration and the EtOAc removed under reduced pressure (<30° C.) and the residue dried in vacuo over KOH. 21/2 gm TLC (S. G. CHCl 3 /MeOH 25/1 I 2 indicator) indicated the presence of a major R f 0.67 and minor component in the protectd dipeptide amide and it was purified on a silica gel column using CHCl 3 /MeOH 25/1. Fractions 41-64 were combined on the basis of TLC S. G. CHCl 3 /MeOH 25:1 and I 2 detection R f 0.65 and evaporated to dryness in vacuo <30° C. Wt. 1.1 gm.
The protected dipeptide was deprotectd with HF in the presence of 10 ml of anisole for 1 hr. at 0° C. The HF was removed in vacuo and the residue triturated 3 times with Et 2 O and dried in a stream of N 2 . The residue was triturated with 0.2 N HOAc filtered and the filtrate lyophylized, 533 mg of crude H-Cys-Ile-NH 2 .
150 mg of the crude peptide were chromatographed on Sephadex G-10 using 0.2 N HOAc as elutant. One ml fractions were collected at a flow rate of 15 ml per hour and fractions 33-36 were combined based on TLC S.G., BAW, ninhydrin and lyophylized 79 mg. R f (BAW). Amino acid ratio: Cys 0.94, Ile 1.0, NH 3 0.8. Percent inhibition collagenase: 35.
EXAMPLE 2
L-pGlu-L-Cys-L-Ile-NH 2
5 Grams benzhydrylamine hydrochloride resin (Beckman) were treated in a solid phase peptide synthesizer with 30% triethylamine in MeCl 2 for five minutes and washed successively, with MeCl 2 (1×) and DMF (2×) and coupled with 6 gm t-Boc-L-isoleucine, 4 gm HOBT and 4 ml DIC overnight. After successive washings with DMF (1×), MeCl 2 (2×) MeOH (1×) and MeCl 2 (2×) the amino acyl resin was ninhydrin slightly positive and was recoupled with the above reagents in the same amount. After the usual washing at this stage it was still ninhydrin slightly positive and after washing the resin with DMF--30% triethylamine followed by DMF it was recoupled with 12 gm t-Boc-L-isoleucine, 8 gm HOBT and 8 ml DIC over 4 days. It was washed as usual at this step previously and coupled with 8.5 gm t-Boc-S-p-methoxybenzyl-L-cysteine, 4 gm HOBT and 4 ml DIC overnight. After the previously described washing at this stage, the peptidyl resin was slightly ninhydrin positive and was recoupled with 8.5 gm t-Boc-S-p-methoxybenzyl-L-cysteine, 4 gm HOBT and 4 ml DIC overnight. After the usual washing at this stage the peptidyl resin was deprotected with TFA, washed in the previously described manner for this stage, and coupled with 6 gm pyro-L-glutamic acid, 4 gm HOBT and 4 ml DIC as previously described for this step. After the usual washing at this stage it was recoupld two succeeding times with the same amounts of reagents as previously described. The peptidyl resin was slightly ninhydrin positive, was washed with diethyl ether, and dried in vacuo.
The peptidyl resin was deprotected and cleaved with HF in the presence of 7 ml of anisole for 1 hour at 0° C. The HF was removed in vacuo overnight the residue washed 3 times with diethyl ether, dried in a current of nitrogen and triturated with 150 ml of 0.2 N HOAc for five minutes and filtered. The filtrate was lyophylized. 346 mg of crude pGlu-Cys-Ile-NH 2 .
63 mg of the above were purified by chromatography on Sephadex G-10 using 0.2 HOAc as solvent at a flow rate of 15 ml per hour with collection of 1 ml fractions.
Collected fractions 67-76 were combined on the basis of TLC SG.BAW system and peptide chlorine spray and lyophylized (R f 0.47 in BAW system), 27 mg. Amino acid analysis of the product gave the following ratios: Glu, 1.0, Cys (not recovered), Ile 0.90, NH 3 1.2. Percent inhibition collagenase: 75.
EXAMPLE 3
CH 3 CO-Pro-Gln-Gly-Ile-Ala-Gly-NH 2
8 Grams of benzhydrylamine hydrochloride resin (Bachem) were treated twice in a solid phase peptide synthesizer with 30% triethylamine in methylene chloride (MeCl 2 ) for five minutes and washed successively, with methylene chloride and dimethylformamide (DMF) and coupled with 5 gm t-Boc-Glycine, 4 gm hydroxybenzotriazole (HOBT) and 4 ml diisopropylcarbodiimide (DIC) overnight in DMF. After successive washings with DMF (1×), MeCl 2 (2×), MeOH and MeCl 2 the resin gave a slightly positive ninhydrin reaction and was recoupled with 5 gm t-Boc Glycine, 4 gm HOBT and 4 ml DIC as previously. After successive washings with DMF (once) MeCl 2 (twice), MeOH and MeCl 2 , the t- Boc-glycyl resin was trace ninhydrin positive and was deprotected for 30 minutes with 50% trifluoroacetic acid in MeCl 2 followed by washing with MeCl 2 (once) 30% triethylamine in DMF (twice) and DMF (twice). The glycyl-resin was coupled with 5.5 gm t-Boc-L-alanine, 4 grams HOBT and 4 ml DIC overnight. The peptidyl resin was washed successively with DMF, MeCl 2 , MEOH and MeCl 2 as previously, was ninhydrin slightly positive and was recoupled with 5.5 gm t-Boc-L-alanine 4 gm HOBT and 4 ml DIC as previously.
It was trace ninhydrin positive at this point, was deprotected with 50% TFA in MeCl 2 as previously washed with MeCl 2 , DMF-triethylamine, and DMF as previously and coupled with 6 gm t-Boc-L-isoleucine, 4 gm HOBT and 4 ml DIC as described for the previous coupling. The peptidyl resin after the usual washing at this step was ninhydrin trace positive was deprotected with TFA washed as previously described for this step and coupled with 6 gm t-Boc-glycine, 4 gm HOBT and 4 ml DIC as previously described. The peptidyl-resin was recoupled twice one with 6 gm t-Boc-glycine and once with 10 gm t-Boc-glycine being trace ninhydrin positive was washed as previously for this step; deprotected with TFA as previously described washed as previously described for this step and coupled with 7.4 gm t-Boc-L-glutamine, 4 gm HOBT and 4 ml DIC as described for the previous couplings. The peptidyl resin was slightly ninhydrin positive and was recoupled with 7.4 gm t-Boc glycine as previously, washed as usual for this step and coupled with 6.5 gm t-Boc-L-proline, 4 gm HOBT and 4 ml DIC as previous. Being slightly ninhydrin positive it was recoupled with 6.5 gm t-Boc-L-proline as described previously and was deprotected with TFA as usual at this stage, washed as usual and coupled with 10 gm acetyl imidazole in DMF overnight. The peptidyl-resin was ninhydrin negative after the second washing at this stage was washed once with Et 2 O and dried in vacuo over KOH.
The above peptidyl resin was deprotected and cleaved with HF in the presence of 8 ml of anisole for 1 hour at 0° C. The HF removed in vacuo and the residue washed 3 times with diethyl ether, dried in a current of nitrogen and triturated with 150 ml of 0.2 N HOAc for five minutes and filtered. The filtrate was lyophilized giving 976 mg crude AcPro-Gln-Gly-Ile-Ala-Gly-NH 2 .
94 mg of crude peptide were partitioned on Sephadex G-25 (medium) using the system BuOH, acetic acid, water 4:1:5 at a flow rate of 25 ml per hour and collecting 1 ml fractions. Collected fractions 74-82 were combined on the basis of TLC silica gel (Merck), BAW system using peptide-chlorine spray for detection (R f 0.39) evaporated to dryness in vacuo below 30° C. and lyophylized from 0.2 N HOAc gave 13 mg of title compound. Amino acid analysis of the product gave the following ratios: Pro 1.03, Glu 1.1, Ala 1.0, Gly 2.3, Ile 1.07, NH 3 2.2. Percent inhibition collagenase: 35.
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The polypeptides
X--R.sub.1 --R.sub.2 --[R.sub.3 ].sub.n --NH.sub.2
where
X is hydrogen, alkanoyl of 2 to 6 carbon atoms, cycloalkylcarbonyl of 6 to 8 carbon atoms or alkoxycarbonyl of 2 to 6 carbon atoms;
R 1 is Cys-, 3-mercapto-Val-, p-Glu-Cys-, p-Glu-3-mercapto-Val- or Pro-Gln-Gly-;
R 2 is Leu-, Ile- or Val-;
R 3 is Ala-, Ala-Gly- or Ala-Gly-Arg-; and
n is 0 or 1;
or a pharmaceutically acceptable salt thereof act as collagenase inhibitors useful in the treatment of diseases involving excessive tissue destruction by collagenase.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims benefit of U.S. Provisional Application No. 61/525,641, filed Aug. 19, 2011, which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention generally relates to planar front illumination systems for the illumination of reflective materials and displays, and more particularly to a light guide plate that conducts light from an edge light source across the face of a reflective display.
BACKGROUND OF THE INVENTION
In contrast to backlit displays (e.g., a backlit transmissive Liquid Crystal Display, LCD), where light is projected through one or more filters or shutters to create an observable image, a reflective display (e.g., an electrophoretic display, EPD) relies on light reflected off of a reflective surface to generate an image. Typically, reflective displays make use of the ambient light present in the environment where the display is used. Planar front illumination systems have been used for many years to augment the ambient light so that reflective displays can be used in darker environments. Typical planar front light illumination systems are made of clear materials and are attached to the front of reflective electronic displays. Front lights provide supplemental illumination to the face of the display when the reflected ambient light is insufficient to create an observable image.
An ideal front light illumination system would be able to efficiently and uniformly direct the light from a supplemental light source toward the display while not emitting stray light toward the environment or user. This ideal front light illumination system passes all of the reflected light to the user without optical loss or optical artifacts. Further, such an ideal front illumination system would be unobtrusive under ambient lighting, i.e., maintaining the contrast, brightness and image quality of the underlying display. In addition, such an ideal front light is also low cost, thin, lightweight, easily manufactured, compatible with touch technologies and widely available.
One common type of front light illumination system includes a light guide plate constructed with numerous microscopic optical surface features. Each of these optical surface features incrementally redirects a small portion of the light inside the light guide plate using reflection or refraction. Ideally, these optical surfaces extract and distribute the luminous flux within the light guide plate uniformly over the surface of the reflective display. To achieve reflection or refraction without mirrored surfaces (which would be costly and/or difficult to produce), optical engineers carefully construct the critical features and angles of the micro optical surface features to reliably and predictably reflect or refract despite the often poor collimation (i.e., the wide distribution of ray angles) of the source illuminators (e.g., LEDs or fluorescent tubes). The refractive and reflective feature of an optical interface is strongly dependent on the relative indices of refraction of the materials on either side of the interface. To maximize the reflective and refractive power of these micro optical features, the micro optical features are usually exposed directly to air to maximize the refractive index difference.
FIG. 1 shows a front illumination system with microscopic optical surface features. This system comprises a reflective display 100 , a light source 101 and a light guide plate 102 . The light guide plate has optical features 103 formed on the outer facing surface of the front illumination system. The light source 101 is typically comprised of one or more cold cathode fluorescent lights (CCFLs) or one or more LEDs suitably arranged to produce moderately collimated light 104 directed into a light injection surface of the light guide plate 102 .
Common additional features known in the art (not shown) include a reflective housing for the light source, surface treatments on the light source 101 and the injection area of the light guide plate 102 , and films or mixing plates inserted between the light source 101 and light guide plate 102 that improve coupling efficiency, uniformity, manufacturability, optical performance and cost. Such additions are applicable to the present invention as well to achieve similar advantageous effects.
The light guide plate 102 has nominally coplanar light guiding surfaces (top and bottom of 102 in FIG. 1 ). A substantial portion of the light 104 injected into light guide plate 102 remains within the light guide plate 102 due to the well-known optical effect of total internal reflection (TIR). Light guide plate 102 has a plurality of micro optic features 103 on its outer surface that redirect a portion of the guided rays 107 downward at each micro optic feature 103 . Ideally, the injected light 104 is uniformly redirected and distributed across the entire surface of the reflective display 100 . To achieve uniformity, the density, height, angle, pitch and shape of the micro optic features 103 and the thickness or shape of the light guide plate 102 is modulated across the breadth and width of the light guide plate 102 to account for the diminished light flux as a function of distance from the light source 101 .
The incrementally redirected light 107 illuminates the reflective display 100 creating reflected rays 109 that can be seen by a user (the user, not shown, is above the front illumination systems as illustrated herein).
A typical front illumination system is usually only activated when the ambient light 108 falling on the display from external sources is insufficient for the user to perceive an image from the reflective display 100 . When ambient illumination 108 is strong enough and consequently the front illumination source is not needed, the front illumination system should be as unobtrusive as possible. Specifically, the front light system should not create unusual reflections, image artifacts or stray light paths that degrade the appearance of the underlying display.
FIG. 2 shows a prior art back illumination system comprising a transmissive display 200 , a light source 201 and a light guide plate 202 . Light guide plate 202 has printed white dots 203 on the outer surface farthest from the display 200 . The light source 200 injects light 204 into the light guide plate 202 , which is then substantially guided by total internal reflection in a lateral direction in the light guide plate 202 . A plurality of small white dots 203 is screen or inkjet printed, etched, stamped, burned, or molded (among the many conventional methods well known in the art of backlight design) on the outer surface of the light guide plate 202 to act as scattering centers that redirect the guided light in a diffuse scattering pattern 207 towards the transmissive display 200 and ultimately toward the viewer (ray 209 ). The density, color, scattering effects and/or sizes of the dots 203 is conventionally varied as a function of position to account for non-uniformity of the light source and to compensate for the consumption of guided light flux as a function of distance from the light source 201 . As is known in the art, additional films 208 are conventionally placed between the back light and the transmissive display (e.g. diffusers and light redirecting films, polarization recycling films, etc.) to improve the optical efficiency, contrast, viewing angle and uniformity of the overall display.
The refractive and reflective feature of an optical interface between two clear materials (e.g. plastic and air) is strongly dependent on the relative indices of refraction of the materials on either side of the interface. To optimize the light guiding (via total internal reflection) and light extraction (via scattering, reflection or refraction) behaviors, the micro optical features are usually exposed directly to air to maximize the refractive index difference.
SUMMARY OF THE INVENTION
The front illumination systems of the prior art that rely on air interfaces, while improving the refracting and reflecting effects, create a number of substantial difficulties that are solved by the present invention. First, air gaps between optical elements over a wide area are difficult to mechanically construct while maintaining thinness and optical quality. If the front illumination system is integrated with a touch panel function, the front face must be sufficiently rigid so that it can maintain the air gap under worst case user finger pressure. Air gaps, due to the high relative index of refraction change, also can create substantial unwanted reflections unless costly anti-reflection coatings are used at each interface.
Second, if air gaps are formed on films that are subsequently laminated to a light guide plate (i.e., an embedded air gap), these air gaps are difficult to control in production as the lamination adhesive can be displaced into the air gaps or grooves, modifying the behavior of the light extraction phenomena and creating uniformity problems. An inherent tradeoff in adhesion strength versus optical quality and feature size is introduced that may not provide satisfactory solutions. Furthermore, air pressure and humidity vary widely (sometimes quickly, e.g., on an aircraft) and condensation, contamination and pressure related effects (if sealed) can create engineering, production and user difficulties.
Further, since the source light is usually poorly collimated, stray light leakage can be inadvertently directed toward the viewer, significantly increasing the brightness of the black level and thus degrading contrast. Such stray light leakage, even if not directed to the viewer, e.g., if exported at a highly acute angle from the front surface of the display system, can still result in poor electro-optical efficiency, which can negatively impact the battery life of mobile devices.
Additionally, controlling the quality of the micro optical features created in a molding process can be challenging as the light guide plate is made thinner and lighter.
Another concern associated with the prior art systems is that mechanical damage, e.g., scratches, may extract light from the light guide plate causing them to be especially highlighted when the front light is activated. Additional mechanical barriers between the light guide plate and the user are often required to prevent scratch highlighting, increasing thickness of the front illumination system and degrading optical performance of the display system.
Front light illumination system design forces a number of compromises where optical design goals, e.g. minimizing ambient reflections and image artifacts. are optimized at the expense of some other constraints, e.g., the cost of anti-reflection coatings and thickness of the system.
The front illumination system of the present invention addresses a number of the aforementioned limitations and forced compromises in the art, enabling a fully laminated, thin, light, economical, uniform, mechanically robust, efficient, highly transparent, low artifact, low leakage front illumination system.
The system of the present invention includes a light guide plate that conducts light from an edge light source across the face of a reflective display. Micro lenses are formed on the inner or outer surface of the light guide. The micro lenses direct the light conducted in the light guide toward the display. A layer having a lower index of refraction is formed on the surface of the light guide plate having the micro lenses. This layer is also known as a stepped index layer and assists in substantially confining the injected light in the light guide plate by total internal reflection. This structural configuration provides a fully laminated front illumination system with a buried light guide layer. In a preferred embodiment, the micro lenses are formed as concave or convex structures in or on the surface of the light guide plate. In another embodiment, a touch screen can be laminated inside protective layers either above or below the light guide plate.
The planar front illumination system of the present invention can be fully laminated with no air gaps and no air pockets in order to maximize ruggedness and minimize internal surface reflections that can degrade optical performance. The system simplifies integration of reflective displays with touch sensor. The system is thin and light. The system maximizes the light directed inward toward the display while minimizing stray light in all other directions. The system generates substantially uniform illumination over a large area and minimizes display and illumination related artifacts such as Moire, ghosting and pressure sensitivity. The system is efficiently and inexpensively produced.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purposes of illustrating the present invention, there is shown in the drawings a form which is presently preferred, it being understood however, that the invention is not limited to the precise form shown by the drawing in which:
FIG. 1 depicts a prior art front illumination system for a reflective display with micro optic features on the front face of a light guide plate;
FIG. 2 illustrates a prior art back illumination system for a transmissive display utilizing a printed dot pattern light guide plate;
FIG. 3 illustrates a planar front illumination system of the present invention with convex micro lenses formed on the inner face of a light guide plate;
FIG. 4 depicts a planar front illumination system of the present invention with convex micro lenses formed on the inner face of a light guide plate with a laminated outer protective sheet;
FIG. 5 illustrates a planar front illumination system of the present invention with concave micro lenses formed on the inner face of a light guide plate;
FIG. 6 depicts a planar front illumination system of the present invention with concave micro lenses formed on the inner face of a light guide plate with a laminated outer protective sheet;
FIG. 7 depicts a planar front illumination system of the present invention with concave micro lenses formed on the outer face of a light guide plate with a laminated outer protective sheet; and
FIG. 8 illustrates a planar front illumination system of the present invention with convex micro lenses formed on the outer face of a light guide plate with a laminated outer protective sheet.
DETAILED DESCRIPTION OF THE INVENTION
The following abbreviations are utilized in the following description, which are intended to have the meanings provided as follows:
CCFL—cold cathode fluorescent light
EPD—electrophoretic display
LCD—liquid crystal display
LGP—light guide plate
LED—light emitting diode
OCA—optically clear adhesive
OLED—organic light emitting diode
PC—polycarbonate
PET—polyethylene terephthalate
PMMA—poly methyl methacrylate
TIR—total internal reflection.
FIG. 3 illustrates an embodiment of the present invention including a reflective display or material 300 , a light source 301 and a light guide plate 302 . A plurality of convex micro lenses 303 is formed on the inner surface of the light guide plate 302 , the surface closest to the reflective display 300 . The light source 301 and light guide plate 302 are coupled as is well known in the art to achieve efficient, uniform and reproducible light injection 304 into the light guide plate 302 . Laterally propagating rays 305 are confined within the light guide plate 302 by, in part, the TIR effect 306 from the inner surface of the light guide plate 302 at the interface to a stepped index layer 310 . The stepped index layer 310 has an index of refraction that is lower than that of the light guide plate 302 . In a preferred embodiment, the stepped index layer 310 is a clear adhesive layer that has a lower index of refraction than the light guide plate 302 in order to support total light guiding by TIR. The outer optical interface of the light guide plate 302 in the embodiment illustrated in FIG. 3 is to air (above plate 302 in FIG. 3 ). This interface also provides for TIR of guided rays 305 . Although air can be used as the stepped index layer, it is preferred to use some other material, such as the above described clear adhesive layer.
The term “stepped index” is borrowed from the fiber optic technology and is distinguished from other indexes such as “graded index” fiber which has a smooth index peak that confines a single mode in order to keep propagation speed very uniform). In a fiber structure, a cylindrical inner core of high index material is cladded with a lower index material to achieve TIR for light propagating down the length of the cylinder. In contrast to the use in fiber structures, the present invention uses its stepped index layer to confining light in only one dimension and leaves the light to freely propagate freely in the other two dimensions. In a fiber, the light is confined in two dimensions and can freely propagate in only one dimension.
Micro lenses 303 formed on the light guide plate 302 perform a light extraction function in which a portion of the incident guided rays 305 are refracted and/or reflected 307 toward the reflective display 300 . The reflective display 300 reflects the extracted light 307 and incident ambient light 308 toward the viewer (not shown) as rays 309 . These reflected rays 309 pass through the light guide plate 302 , optical adhesive layer 310 and micro lenses 303 with only small reflection and refraction effects.
In one embodiment of the present invention, the areal density of the micro lenses 303 , with respect to the surface area of the surface of light guide plate 302 , is varied within the light guide plate 302 to compensate for light source nonuniformity and variations in the optical flux in the light guide plate 302 as a function of position in order to present a substantially uniform light source to the display. In a preferred embodiment of the present invention, the density of the micro lenses 303 is increased farther from the light source 301 to achieve a more uniform flux 307 over the length of light guide plate 302 . In a further embodiment, the micro lens 303 density is adjusted near edges of the light guide plate 302 to account for side and opposing surface reflections and optical losses in order to achieve a more uniform extracted light field 307 . The areal density of the micro lenses 303 can range from near zero, <1% by area, to very high, nearly 100%, depending on the non-uniformity of the light flux and the extraction efficiency of the micro lenses 303 .
The density of the micro lenses 303 can be simulated to get an initial areal density, and then empirically tuned during the manufacturing process, e.g., fabricating a light guide plate 302 with a specific areal density of micro lenses 303 , measuring the uniformity of the light on the display 300 and repeating this process, changing the density over many cycles to optimize the uniformity of the light flux
In a further embodiment of the present invention, the area of each micro lens 303 is kept substantially smaller than the underlying reflective display 300 unit pixel area so that the micro lenses 303 do not objectionably distort the underlying pixels (not shown in FIG. 3 ).
In a further embodiment of the present invention, the height and profile of each micro lens 303 is engineered, e.g., by making substantially microscopically smooth edges and profile transitions, to allow the optical adhesive 310 to uniformly coat and fill all spaces around micro lenses 303 to prevent microscopic air bubbles from being trapped or forming after some post-manufacturing environmental exposure, e.g., exposure to low external air pressure at high altitudes, heat and/or humidity.
In a further embodiment, the convex shape of micro lenses 303 is tuned to the refractive indices of the light guide plate 302 and the optically clear adhesive layer 310 to optimize uniformity of the extracted light, manufacturing yield, tooling complexity and material cost by making the optical reflection and refractive effects insensitive to manufacturing and material variations.
In a further embodiment, the micro lenses 303 are made sufficiently small e.g., 50 microns or less, and spaced sufficiently closely together and sufficiently elevated above the image plane of display 300 so that the extracted light 307 reaching the display 300 image plane is substantially spatially uniform.
In a still further embodiment, the micro lenses 303 are designed to minimize direct reflection from ambient illumination 308 and to minimize distortion of the reflected image 309 through refraction by, for example, constraining the maximum angle of the micro lenses 303 relative to the light guide plate 302 . The micro lens 303 shape, micro lens 303 edge geometry, OCA 310 index of refraction, and OCA 310 softness, i.e., the ability to flow around the micro lens 303 shape, contribute to the contrast, brightness, clarity, and overall optical performance of he combined display system. By balancing the multiple demands on the micro lens 303 shape in accordance with the present teachings, one skilled in the art can minimize the perceived degradation of the reflective display 300 performance, e.g., contrast, brightness, clarity, caused by the front illumination system of the present invention.
A large number of materials are available for constructing the present invention. Light guides 302 typically have substantially flat surfaces and are commonly constructed of PMMA or PC plastic, although any optically clear material, e.g., glass, with an index of refraction that is higher than the surrounding material, e.g., air or vacuum above and the OCA 310 below the light guide plate 302 in FIG. 3 . Similarly, the light source 301 can assume many forms and be made from many materials. For example a CCFL, an OLED or one or more LED lamps coupled to a light bar or mixing plate may be used within the present teachings as the light source 301 . One or more sides of the light guide plate 302 may have injecting surfaces with one or more light sources 301 . For simplicity, only one light source is shown in the figures but as is well known in the art, the number and positions of light sources, e.g., placed at one or more edges or corners, can be varied given system constraints on cost, light uniformity, brightness, mechanical boundaries, form factor, etc. Other light sources (e.g., incandescent lamps, lasers, vacuum fluorescent tubes) could be used.
The optical interfaces and surfaces of the components of the present invention can be coated, shaped, processed, textured or modified by the inclusion or application of specialized films so as to achieve any number of standard desirable changes in properties. These films can be used to improve light confinement, improve light guide injection uniformity, reduce stray reflections, improve light source 301 to light guide plate 302 coupling efficiency, improve light guide plate 302 to reflective display 300 interface or reduce the thickness and weight of the system. Such additions and modifications are well known in the art of illumination design and are available at the discretion of the designer to achieve the desired balance between cost, performance, yield, etc., without detracting from the scope of the present teachings.
Many options are available for fabricating micro lenses 303 on the light guide plate 302 . In one embodiment, the micro lenses 303 are printed using, e.g., an industrial inkjet printer and a clear UV cured polymer ink. Such printers can directly apply small, e.g., 30 microns or less, clear polymer dots precisely, rapidly and inexpensively onto the light guide plate.
In another embodiment, micro lenses 303 can be formed on the surface of the light guide plate 302 by an injection molding process when the light guide plate 302 is manufactured. In this process, a metal mold is tooled with precise micro lens indentations and plastic is injected into the mold creating convex lenses 303 at each metal mold indentation.
Micro lenses 303 can also be hot stamped, molded, mechanically embossed, engraved, chemically etched and/or created lithographically on the light guide plate 302 . Substituting such alternative techniques for creating micro lenses 303 on the inner surface of a front illumination light guide plate 302 are known to those skilled in the art and are included in the scope of the present teachings.
The exact shape of the micro lenses 303 can be substantially changed within the present teachings, e.g., circular, hemispherical, triangular, square, rectangular or oval shapes among others are all possible. In addition or in the alternative, lensing lines, segments or traces could be substituted for the round micro lenses 303 illustrated in FIG. 3 .
In one embodiment of the present invention, the light guide plate 302 and the stepped index layer 310 , e.g., an optically clear adhesive layer, can be manufactured as a unit, for later incorporation in the assembly of a completed device having a light source 301 and a display 300 .
In an alternative embodiment, stepped index layer 310 , with an index of refraction lower than the light guide plate 302 can be co-extruded with the light guide 302 to achieve both protection and light confinement by TIR within in the light guide plate 702 .
FIG. 4 shows a further embodiment of the present invention comprising a reflective display or material 400 , a light source 401 and a light guide plate 402 . A plurality of convex micro lenses 403 is formed on the inner surface of the light guide plate 402 , the surface closest to the reflective display 400 . The light source 401 and light guide plate 402 are coupled as is well known in the art to achieve efficient, substantially uniform and reproducible light injection 404 into the light guide plate 402 . Laterally propagating rays 405 are confined within the light guide plate 402 by a TIR effect from the inner surface of the light guide plate 402 at the interface to a stepped index layer 410 . In a preferred embodiment, the stepped index layer 410 is a clear adhesive layer that has a lower index of refraction than the light guide plate 402 in order to support TIR light guiding.
An outer clear protective sheet 412 is laminated to the top of light guide plate 402 with an additional stepped index layer 411 disposed between the protective sheet 412 and the light guide plate 402 . In a preferred embodiment, the stepped index layer is an optically clear adhesive layer that has a lower index of refraction than the light guide plate 402 . This upper optical interface of light guide plate 402 also supports light guiding of the transversely travelling rays 405 by TIR.
In an alternative embodiment, a protective layer 412 with an index of refraction lower than the light guide plate 402 can be coextruded with the light guide plate 402 to achieve both protection and light confinement by TIR within the light guide plate 402 . In this embodiment, no adhesive layer is required and the protective layer 412 acts as the stepped index layer.
The micro lenses 403 of the embodiment illustrated in FIG. 4 perform the same light extraction function as the micro lenses 303 described above with respect to FIG. 3 . Further, all of the above description with respect to the manufacture and variations in the micro lenses 303 applies equally to the micro lenses 403 .
Micro lenses 403 formed on the light guide plate 402 perform a light extraction function in which a portion of the incident guided rays 405 are refracted and/or reflected 407 toward the reflective display 400 . The reflective display 400 reflects the extracted light 407 and incident ambient light 408 toward the viewer (not shown) as rays 409 . The incident 408 and reflected rays 409 pass through the protective sheet 412 , optical adhesives 410 411 , light guide plate 402 and micro lenses 403 with only small reflection and refraction effects.
FIG. 5 shows a further embodiment of the present invention comprising a reflective display or material 500 , a light source 501 and a light guide plate 502 . A plurality of concave micro lenses 503 is formed on the inner surface of the light guide plate 502 , the surface closest to the reflective display 500 . The light source 501 and light guide plate 502 are coupled as is well known in the art to achieve efficient, substantially uniform and reproducible light injection 504 into the light guide plate 502 . Laterally propagating rays 505 are confined within the light guide plate by TIR from the inner surface of the light guide plate 502 at the interface to a stepped index layer 510 . In a preferred embodiment, the stepped index layer 510 is a clear adhesive layer that has a lower index of refraction than the light guide plate 502 in order to support TIR.
Micro lenses 503 on the light guide plate 502 perform a light extraction function in which a portion 507 of the incident guided rays 505 are refracted and/or reflected by the lenses 503 and are directed toward the reflective display 500 . The reflective display 500 reflects the extracted light 507 and incident ambient light 508 toward the viewer (not shown) as rays 509 . These reflected rays pass through the light guide plate 502 , stepped index layer 510 and micro lenses 503 without substantial losses or distortions.
All of the above description with respect to the variations in the micro lenses 303 applies equally to the micro lenses 503 .
Concave micro lenses 503 can be formed on the surface of the light guide plate 502 by an injection molding process when the light guide plate 502 is manufactured. In this process, a metal mold is tooled with precise micro lens bumps and plastic is injected into the mold creating concave lenses at each metal mold bump. Numerous other processes known in the art can be adapted to create concave lens shapes, including hot stamping, etching, photolithography, sandblasting, mechanical engraving or drilling and laser engraving.
FIG. 6 shows a further embodiment of the present invention comprising a reflective display or material 600 , a light source 601 and a light guide plate 602 . A plurality of concave micro lenses 603 is formed on the inner surface of the light guide plate 602 , the surface closest to the reflective display 600 . The light source 601 and light guide plate 602 are coupled as is well known in the art to achieve efficient, uniform and reproducible light injection 604 into the light guide plate 602 . Laterally propagating rays 605 are confined within the light guide plate 602 by TIR from the inner surface of the light guide plate 602 at the interface to a stepped index layer 610 . In a preferred embodiment, the stepped index layer 610 is a clear adhesive layer that has a lower index of refraction than the light guide plate 602 in order to support TIR light guiding. An outer clear protective sheet 612 is laminated to the light guide plate 602 with an intervening stepped index layer 611 . In a preferred embodiment, stepped index layer 611 is an optically clear adhesive with a lower index of refraction than the light guide plate 602 in order to support light guiding by TIR.
In an alternative embodiment, a protective layer 612 with an index of refraction lower than the light guide plate 602 can be coextruded with the light guide plate 602 to achieve both protection and light confinement by TIR within in the light guide plate 602 . In this embodiment, no adhesive layer is required and the protective layer 612 acts as the stepped index layer.
Micro lenses 603 on the light guide plate 602 perform a light extraction function as described above with respect to FIG. 5 in regard to concave micro lenses 503 . Further, all of the above description with respect to the variations in the micro lenses 303 applies equally to the micro lenses 603 .
Micro lenses 603 formed on the light guide plate 602 perform a light extraction function in which a portion of the incident guided rays 605 are refracted and/or reflected 607 toward the reflective display 600 . The reflective display 600 reflects the extracted light 607 and incident ambient light 608 toward the viewer (not shown) as rays 609 . The incident 608 and reflected rays 609 pass through the protective sheet 612 , optical adhesives 610 611 , light guide plate 602 and micro lenses 603 without substantial losses or distortions.
FIG. 7 shows a further embodiment of the present invention comprising a reflective display or material 700 , a light source 701 and a light guide plate 702 . A plurality of concave micro lenses 703 is formed on the outer surface of the light guide plate 702 , the surface that is farthest from the reflective display 700 . The light source 701 and light guide plate 702 are coupled as is well known in the art to achieve efficient, substantially uniform and reproducible light injection 704 into the light guide plate 702 . Laterally propagating rays 705 are confined within the light guide plate 702 by the TIR effect from the inner surface of the light guide plate 702 at the interface to a stepped index layer 710 . In a preferred embodiment, the stepped index layer is an optically clear adhesive layer that has a lower index of refraction than the light guide plate 702 in order to support TIR light guiding.
An outer clear protective sheet 712 is laminated to the top of light guide plate 702 with an additional stepped index layer 711 . In a preferred embodiment, the stepped index layer 711 is an optical adhesive layer that has a lower index of refraction than the light guide plate 702 . This upper optical interface of light guide plate 702 also supports light guiding of the transversely travelling rays 705 by TIR.
In an alternative embodiment, protective layer 712 with an index of refraction lower than the Light guide plate 702 can be co-extruded with the light guide 702 to achieve both protection and light confinement by TIR within in the light guide plate 702 . In this embodiment, no adhesive layer is required and the protective layer 712 acts as the stepped index layer.
Micro lenses 703 formed on the light guide plate 702 perform a light extraction function in which a portion 707 of the incident guided rays 705 are refracted and/or reflected toward the reflective display 700 . The extracted rays 707 pass through the light guide 702 and the clear adhesive layer 710 to the reflective display 700 . Reflective display 700 reflects the extracted light 707 and the ambient light 708 toward the viewer as rays 709 . These reflected rays 709 pass through the clear areas of light guide plate 702 and micro lenses 703 with only small reflection and refraction effects.
All of the above description with respect to the manufacture of the concave micro lenses 503 and the variations in the micro lenses 303 apply equally to the micro lenses 703 .
FIG. 8 shows a further embodiment of the present invention comprising a reflective display or material 800 , a light source 801 and a light guide plate 802 . A plurality of convex micro lenses 803 is formed on the outer surface of the light guide plate 802 , the surface that is farthest from the reflective display 800 . The light source 801 and light guide plate 802 are coupled as is well known in the art to achieve efficient, uniform and reproducible light injection 804 into the light guide plate 802 . Laterally propagating rays 805 are confined within the light guide plate 802 by the TIR effect from the inner surface of the light guide plate 802 at the interface to a stepped index layer 810 . In a preferred embodiment, the stepped index layer 810 is a clear adhesive layer that has a lower index of refraction than the light guide plate 802 in order to support TIR light guiding.
An outer clear protective sheet 812 is laminated to the top of light guide plate 802 with an additional stepped index layer 811 . In a preferred embodiment, the stepped index layer 811 is an optically clear adhesive layer that preferably has a lower index of refraction than the light guide plate 802 . This upper optical interface of light guide plate 802 also supports light guiding of the transversely travelling rays 805 by total internal reflection.
In an alternative embodiment, a protective layer 812 with an index of refraction lower than the light guide plate 802 can be coextruded with the light guide plate 802 to achieve both protection and light confinement by TIR within in the light guide plate 802 . In this embodiment, no adhesive layer is required and the protective layer 812 acts as the stepped index layer.
Micro lenses 803 formed on the light guide plate 802 perform a light extraction function in which a portion 807 of the incident guided rays 805 are refracted or reflected toward the reflective display 800 . The extracted rays 807 pass through the light guide 802 and the clear adhesive layer 810 to the reflective display 800 . Reflective display 800 reflects the extracted light 807 and the incident ambient light 808 toward the viewer (not shown) as rays 809 . These reflected rays 809 pass through the light guide plate 802 , optical adhesives 810 811 , protective sheet 812 and micro lenses 803 without substantial losses or distortions.
Further, all of the above description with respect to the manufacture and variations in the micro lenses 303 apply equally to the micro lenses 803
In the above embodiments of the present invention, the protective sheets 412 , 612 , 712 and 812 respectively provide a layer of mechanical separation between the light guiding layers 402 , 602 , 702 and 802 and the user so that mechanical marks, or surface contamination, e.g., scratches, gouges, oil, dirt, water, fingerprints, dust, etc. do not create inadvertent light extraction toward the user. Further, the protective sheets 412 , 612 , 712 and 812 can support additional layers and surface treatments that enhance the performance, e.g., anti-glare/haze, anti-reflection, anti-fingerprint, anti-scratch, hardcoat or other enhancements. If these additional layers are applied directly to the light guide plates 402 , 602 , 702 and 802 , they would possibly degrade the light guide confinement performance and adversely affect contrast, brightness or other display performance criteria under ambient or front lighted conditions.
In an additional embodiment of the present invention, the light guide plates 302 , 402 , 502 , 602 , 702 and 802 are fabricated from polycarbonate with an index of refraction of approximately 1.585, and the optical adhesive layers 310 , 410 , 411 , 510 , 610 , 611 , 710 , 711 , 810 and 811 are made of a low index optical adhesive with an index of refraction between 1.32 and 1.50. In an alternative embodiment of the present invention, the light guide plates 302 , 402 , 502 , 602 , 702 and 802 are fabricated from PMMA with an index of refraction of approximately 1.49 and the optical adhesive layers 310 , 410 , 411 , 510 , 610 , 61 , 710 , 711 , 810 and 811 are made of a low index optical adhesive with an index of refraction between 1.32 and 1.45. Those skilled in the art will recognize the wide variety of light guide materials and adhesive laminating materials that can be substituted within the general framework of the present teachings to create the conditions for sufficient confinement by TIR within the light guide plates 302 , 402 , 502 , 602 , 702 and 802 .
Those skilled in the art will also recognize that the protective layers 412 , 612 , 712 and 812 can be used as a substrate for integrating a fully laminated touch sensor onto the top of the display system. Such laminated touch sensors are well known in the art, e.g., projected capacitance, surface capacitance, and infrared, among others. The lamination of such a touch sensor as, or in addition to, the top protective layers 412 , 612 , 712 and 812 are within the scope of the present invention.
The light sources 301 , 401 , 501 , 601 , 701 and 801 are only shown as firing from a single edge to simplify the drawings. In practice, these light sources 301 , 401 , 501 , 601 , 701 and 801 can inject light from any or all edges and/or from one or more corners of the light guide plates 302 , 402 , 502 , 602 , 702 and 802 . A string of LEDs or point light sources arranged linearly along one or more edges of the light guide plate 302 , 402 , 502 , 602 , 702 and 802 can also constitute the light source 301 , 401 , 501 , 601 , 701 and 801 within the present invention.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and other uses will be apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the gist and scope of the disclosure.
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A system for illuminating a reflective display or other material from a planar front device and a method of manufacture thereof. The system includes a light guide plate that conducts light from an edge light source across the face of a reflective display. Micro lenses are formed on the inner or outer surface of the light guide and direct the light conducted in the light guide toward the display. A stepped index layer is formed on the surface of light guide plate containing the micro lenses. The stepped index layer has an index of refraction lower than an index of refraction of the light guide plate to assist in the total internal reflection of light injected into the light guide plate. A top layer protective coat or touch screen can be laminated to the outside of the light guide plate.
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BACKGROUND OF THE INVENTION
The data storage industry has developed various libraries for various media. Since there are many different types of applications, there are many different styles of libraries. Several types of libraries use multiple shafts to guide and drive a picker assembly from drives to media stores. Precision shafts or guide elements can be costly and may require time consuming factory adjustments that could require readjustment in the field. The addition of a gear rack or leadscrew to drive the picker can cause binding if not lined up properly initially and could shift over time.
Commonly, dual shafts allow for the picker and lift assembly to be rotated to service several columns of media stores. However, both shafts must be perfectly parallel to avoid binding the picker assembly during vertical motion. Also, it has been difficult to rotate the two shafts between storage columns to precisely locate the picker for accessing the drives and media stores. If the picker is not precisely located, repeated insertion and withdrawal of media into the drives and media stores can cause excessive wear. Any slight offset in the vertical position of the drives and media stores can cause difficulty in precise picker positioning.
There is a need for a data storage library with a media transport element or picker which can use a single shaft to position the picker between storage columns and raise and lower the picker to access drives and media stores. There is also a need for a data storage library with a simple means of precisely positioning the picker adjacent the drives and media stores regardless of any slight deviations in the position of the drives and media stores from nominal.
SUMMARY OF THE INVENTION
A data storage library for storing and accessing data storage media, consisting of a housing, a storage array within the housing, the storage array having a wall, a media storage element arranged adjacent the storage array wall for holding storage media, a data transfer element arranged adjacent the storage array wall for reading and writing information on the storage media, an import/export element to transfer the storage media into and out of the data storage library, and a media transport element which moves along the storage array wall, the media transport element following any deviations in the wall to precisely position itself adjacent the media storage element and data transfer element.
A principal object and advantage of the present invention is that the media transport element follows the boundary or wall of the storage array to precisely position the media transport element for accessing the media storage element and data transfer element, regardless of any irregularities in the storage array due to thermal expansion, stress relieving, and chassis deflection.
A second principal object and advantage of the present invention is that it uses a single shaft to position the media transport element between storage arrays and to move the media transport element between media storage elements and data transfer elements within a storage array. Having a single shaft, rather than dual shafts, eliminates the need for precise parallel alignment between two shafts.
A feature of the present invention is that the picker has an engagement wheel which rides along the wall of the storage array and a magnet which holds the engagement wheel in contact with the wall.
Another feature of the present invention is that the picker rotates about the single shaft on a picker bushing which has sufficient clearance from the shaft to allow the picker to ride along the storage array wall.
Another feature of the present invention is that the shaft has gear rack teeth machined into one face and there is a lift motor to move the media transport element along the shaft, eliminating the need for a separate pulley system for moving the media transport element.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the data storage library.
FIG. 2 is a detailed perspective view of the media transport element.
FIG. 3 is a detailed view of the engagement wheel and magnet.
FIG. 4 is a detailed view of the shaft and lift motor.
FIG. 5 is a detailed view of the stepper motor and position sensor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The data storage library of the present invention is generally shown in the Figures as reference numeral 10.
The data storage library 10 consists of a housing 20 which provides a protective environment for the other components of the data storage library 10.
Within the housing 20 is at least one storage array 30 which holds a number of other components. Preferably, more than one storage array 30 is contained within the housing 20. The storage array 30 has a boundary or wall 32. In the preferred embodiment, the storage array 30 is a vertical column, but any other orientation or shape such as horizontal or polygonal is also possible, it being understood that the only requirement for the storage array 30 is to have a boundary or wall 32 along which a media transport element may move as will be further described below.
Arranged within the storage array 30 is at least one and preferably several media storage elements 40. The media storage elements 40 hold the storage media when the storage media are not being read or written to. The storage media can be any media which can be used to record information, such as data and graphics. The recording means may be magnetic, optical, or any other equivalent recording means known in the storage media art. Preferably, the storage media are compact discs (CDs). Preferably, the media storage elements 40 are trays which hold the CDs.
Also arranged within the storage array 30 is at least one and preferably several data transfer elements 50, which are used to read and write information on the storage media. Preferably, the data transfer elements 50 are compact disc drives (CD drives) but the data transfer elements 50 may be any equivalent device such as an optical disc drive, a cassette drive, floppy disc drive or hard drive. The latest CD drives allow the CD to be written to as well as read from, in which case the media is called a PD. Such writable PDs are readily available, an example being the Panasonic LM-RP6500A PD.
An import/export element 60 is used to transfer the storage media into and out of the data storage library 10. The import/export element may be positioned anywhere within the housing 20 as long as its position relative to a storage array 30 is known.
All of the media storage elements 40 and data transfer elements 50 are arranged adjacent the boundary or wall 32 of the storage array, the importance of which will become clear below. Each of the media storage elements 40 and data transfer elements 50 has a slot or other equivalent means S by which the storage media may be inserted and removed. The slot S is at the same distance from the boundary or wall 32 in each of the media storage elements 40 and data transfer elements 50. Preferably, adapters are used to compensate for any difference in the position of the slot S between the media storage elements 40 and data transfer elements 50. Such adapters may preferably attach to the wall 32 of the storage array 30 and position the media storage elements 40 and data transfer elements 50 at the correct distance from the wall 32.
A media transport element 70 is movable within the housing 20 to move the storage media among media storage elements 40, data transfer elements 50, and import/export element 60 within a storage array 30, and also to move between storage arrays 30 when there is more than one storage array.
In order to precisely position the media transport element 70 for accessing the media storage elements 40 and data transfer elements 50, the media transport element 70 follows the boundary or wall 32 of the storage array 30. Because each of the media storage elements 40 and data transfer elements 50 is arranged adjacent the boundary or wall 32 and because each slot S is the same distance from the boundary or wall 32, the media transport element 70 may be precisely positioned so as to insert or remove storage media into or from one of the media storage elements 40 and data transfer elements 50 without any strain being imposed on any component, even if the storage array 30 has any irregularities due to thermal expansion, stress relief, or chassis deflection. That is, even if the media storage elements 40 and data transfer elements 50 are not precisely aligned with each other, the media transport element 70 can compensate easily for any misalignment without any complicated or expensive position sensors.
The need for such precise positioning is great, because friction and strain may produce part failure over the many millions of positionings if the alignment is off by more than 10 thousandths of an inch.
In the preferred embodiment, the media transport element 70 is a robotic picker 72. In the preferred embodiment, the picker 72 moves along a single shaft 80 to position the picker adjacent one of the media storage elements 40 and data transfer elements 50, the motion of the picker 72 along the shaft 80 being constrained by the storage array 30. The single shaft 80 also rotates about its axis as shown in the Figures to move the picker 72 between storage arrays 30. To allow the picker 72 to follow the boundary or wall 32 of the storage array, the picker 72 rotates slightly about the shaft 80.
In the preferred embodiment, the picker 72 has an engagement wheel 74 which rides along the boundary or wall 32 of the storage array 30. An engagement magnet 76 holds the engagement wheel 74 in contact with boundary or wall 32. Preferably, the magnet 76 does not contact the boundary or wall 32, but is held a slight distance away from the boundary or wall 32 by the engagement wheel 74. In this manner, the wheel rolls with very little friction along the wall 32.
In the preferred embodiment, the picker 72 rotates slightly about the shaft 80 on a picker bushing 82. The picker bushing 82 has sufficient clearance from the shaft 80 as to allow the picker to ride along the storage array wall 32 and to move slightly toward and away from the storage array wall 32 as it follows the wall 32. Alternatively, the stepper motor and associated gears may have a slight clearance which allows the picker to ride along the storage array wall 32 and to move slightly toward and away from the storage array wall 32 as it follows the wall 32.
Preferably, the data storage library further comprises a stepper motor 90 which rotates the shaft 80 between storage element arrays 30. A sensor 100 detects that the picker has been positioned adjacent a storage array wall 32. The sensor may preferably be an optical sensor. The stepper motor is then used to precisely position the picker 72 adjacent another storage array wall 32. Preferably, the position of the import/export element 60 relative to the storage arrays 30 is known, and the stepper motor may be used to position the picker 72 adjacent the import/export element 60.
In the preferred embodiment, the shaft 80 has gear rack teeth 104 machined into one face of the shaft 80. A lift motor 110 engages the gear rack teeth 104 to move the picker 72 along the shaft 80. The lift motor 110 has an encoder 112 which is used to determine the position of the picker 72 along the shaft 80.
Preferably, the picker 72 has a slider 120 thereon and a slider motor 122 attached to the slider 120 for moving the slider toward and away from the storage array 30. The slider has a finger 124 which is used to grip the storage medium to insert and remove the storage medium from one of the media storage elements 40 and data transfer elements 50.
In operation, storage media are loaded into the media storage elements 40 either by opening the housing 20 or by using the import/export element 60 to load one medium at a time. If the import/export element 60 is used, the operator signals the data storage library 10 to open the import/export element 60. Storage medium is then placed within the import/export element 60 and the import/export element 60 is closed. The data storage library 10 then signals the picker 72 to retrieve the storage medium from the import/export element 60 and place the storage medium in one of the media storage elements 40.
At initialization, the data storage library 10 rotates the shaft 80 until the sensor 100 detects the presence of the picker 72 against one storage array wall 32. The shaft 80 is then rotated until the sensor 100 detects the presence of the picker 72 against the wall of another storage array 30. The lift motor 110 then raises the picker 72 slightly to signal the zero position vertically. The picker then being at the 0,0 position on the x and y axes of movement, the stepper motor 90 may then be used to position the picker 72 adjacent the wall 32 of any storage array 30. The encoder 112 may be used to position the picker 72 adjacent any of the media storage elements 40 and data transfer elements 50.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.
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A data storage library for storing and accessing data storage media, consisting of a housing, a storage array within the housing, the storage array having a wall, a media storage element arranged adjacent the storage array wall for holding storage media, a data transfer element arranged adjacent the storage array wall for reading and writing information on the storage media, an import/export element to transfer the storage media into and out of the data storage library, and a media transport element which moves along the storage array wall, the media transport element following any deviations in the wall to precisely position itself adjacent the media storage element and data transfer element.
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This application is based on and claims priority under 35 U.S.C. § 119 with respect to Japanese Application No. 11-359208 filed on Dec. 17, 1999, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention generally relates to a vehicle seat apparatus. More particularly, the present invention pertains to a seat slide apparatus for a vehicle having a combination of steel and light metal rails.
BACKGROUND OF THE INVENTION
Known vehicle seat slide apparatus are basically composed of a lower rail fixed to the vehicle floor, an upper rail which holds the seat to slidably move the seat in the vehicle longitudinal direction relative to the lower rail, and a lock mechanism for effecting engagement and disengagement of the lower and upper rails for adjusting the seat position. The seat slide apparatus should be light in weight and the sliding resistance of the upper rails relative to the lower rail should be relatively small. For this reason, the rails are made from lightweight metal alloy such as by aluminum alloy extrusion forming, and rollers or balls are positioned between the sliding surfaces of the rails to reduce frictional resistance.
However, an undesirably large number of components is required to produce these types of seat sliding apparatus because balls or rollers are required as well as a mechanism for supporting the balls or rollers. In addition, the shape of the rail must be relatively accurately dimensioned, especially at the ball or roller holding portion. However, it is difficult to maintain desired dimensions within a tolerance range using an extrusion forming method.
One proposal for addressing some of the disadvantages and drawbacks associated with the construction of known seat sliding apparatus is described in Japanese Utility Model Published Application No. Hei 6(1994)-74465. This seat slide apparatus is composed of a lower rail made of steel, an upper rail comprised of a sliding portion made of aluminum alloy and a seat support portion made of steel, and a lock mechanism engageable with a hole in the lower rail and supported on the seat support portion. The lower portion of the sliding member of this apparatus possesses an H-shaped cross-section having sufficient wall thickness. The apparatus is designed to prevent excessive play of both rails and smoothly slide the upper rail relative to the lower rail by contacting parts of both the upper portions and the outer surface of the vertical portions of the H-shaped part with the inner wall surface of the hollow portion of the lower rail.
So long as the dimensions of the two rails are kept within a small dimensional tolerance, this construction of the seat sliding apparatus reduces the number of components, such as the balls or rollers, without causing sticking during the sliding movement of the upper rail relative to the lower rail due to the contact between the different materials such as steel material and aluminum alloy material, However, this construction of the seat sliding apparatus requires high accuracy forming for the rails. Even a slight deviation from the tolerance causes an excessive play between both rails, thus increasing the sliding resistance.
In light of the foregoing, a need exists for a seat sliding apparatus that is not as susceptible to the disadvantages and drawbacks identified above.
A need exists for a seat slide apparatus which utilizes a different technological solution to produce an improved seat slide apparatus.
SUMMARY OF THE INVENTION
According to the present invention, the seat slide apparatus is designed so that a portion of the steel upper rail contacts the inner wall of the hollow portion of the lower rail by using a spring force. It is preferable to provide a surface portion having indented and projecting portions (grooves and ridges) on the inner wall of the hollow portion of the lower rail. A portion of the upper rail is elastically in contact with the surface portion having the projections.
The dimensional tolerance range of the upper rail and the lower rail can be wider by utilizing the elastic characteristics of the upper rail and without causing excessive play of the upper rail during sliding motion relative to the lower rail. In addition, the sliding resistance is kept constant and the assembly work is easier to carry out.
Thus, according to one aspect of the invention, a seat slide apparatus includes a lower rail made from light metal alloy materials having a pair of side portions upwardly extending from both ends of the base portion, with each surface of the inner wall of the side portion having a projection portion. An upper rail made from steel material has flange portions upwardly extending from both ends of a horizontal bottom portion, and each flange portion elastically contacts the projection portions.
According to another aspect of the invention, a vehicle seat slide apparatus includes a lower rail, an upper rail and a lock mechanism. The lower rail is adapted to be secured to the floor of the vehicle and includes a base portion and a pair of side portions. Each of the side portions extends upwardly from one end of the base portion and possesses an inwardly inclined portion. A plurality of projections extend from the inner wall surface of each inclined portion. The upper rail includes a horizontal bottom portion and a pair of flange portions extending upwardly from ends of the horizontal bottom portion. Each flange portion faces one of the inclined portions of the side portion of the lower rail, and each of the flange portions of the upper rail is in contact with the projections of one of the inclined portions. The lock mechanism is engageable with a portion of the lower rail and the upper rail to fix the position of the upper rail with respect to the lower rail.
According to another aspect of the invention, a seat slide apparatus for a vehicle includes a lower rail adapted to be secured to the vehicle floor, an upper rail and a lock mechanism. The lower rail includes a base portion and a pair of side portions, with each of the side portions extending upwardly from one end of the base portion. The upper rail includes a horizontal bottom portion and a pair of flange portions extending upwardly from ends of the horizontal bottom portion. Each flange portion includes a surface portion facing a surface portion of the side portion. A plurality of projections extend away from either the surface portion of each side wall or the surface portion of each flange, and the other of the surface portion of each side wall and the surface portion of each flange contacts the projections. The lock mechanism is adapted to engage a portion of the lower rail and the upper rail to fix the position of the upper rail with respect to the lower rail.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The foregoing and additional features and characteristics of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawing figures in which like reference numerals designate like elements and wherein:
FIG. 1 is a perspective view of a seat slide apparatus according to the present invention; and
FIG. 2 is a cross-sectional view of the seat slide apparatus shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the seat slide apparatus 1 according to the present invention includes a lower rail 3 that is adapted to be fixed to the vehicle floor through a bracket 2 , an upper rail 4 slidably disposed in the longitudinal direction relative to the lower rail 3 , and a lock mechanism 7 operated by a handle 5 and engageable with holes 6 provided on the lower rail 3 . The lock mechanism 7 is supported by the upper rail through a bracket 8 .
Referring to FIG. 2, the lower rail 3 is formed by extrusion of light metal alloy such as aluminum alloy and includes a pair of side portions 10 extending upwardly from both sides of a base portion 9 , an upwardly and slightly inwardly inclined portion 11 extending from each of the side portions 10 , and a tip portion 12 extending downward from the top end of each inclined portion 11 . A plurality of rollers 13 are situated on the base portion 9 .
The holes 6 receiving the engaging part of the lock mechanism 7 are provided on one of the side portions 10 of the lower rail 3 . The inner wall surface of the inclined portion 11 of each side portion 10 is provided with a surface region or surface portion 14 having one or more convex elements or projections. Thus, the surface portion possesses surface characteristics differing from the surface characteristics of the portion of the inner wall surface of each side portion adjoining the surface portion 14 . Generally speaking, the surface portion 14 possesses a plurality of spaced apart projections, with grooves being defined between adjacent projections. The projections or protuberances of the surface portion 14 can be, for example, knurled or grooved, or can be a somewhat wave-shaped configuration.
The upper rail 4 is composed of two generally L-shaped plates made from spring steel. The two generally L-shaped plates are connected to form a reverse T- shaped upper rail. The end of the horizontal bottom portion 16 of each plate extends upwardly and inwardly to form a flange portion 15 at each side of the upper rail. Both flange portions 15 are adapted to be elastically deformed inwardly or outwardly relative to the horizontal bottom portion 16 . In addition, the horizontal bottom portions 16 of the upper rail 4 are in contact with the rollers 13 .
A through hole 17 is provided in one of the flange portions 15 of the upper rail 4 . The tip end of the lock mechanism 7 forming an engaging part of the lock mechanism 7 extends into and is engageable with the hole 17 in the flange portion 15 and one of the holes 6 in the side portion 10 of the lower rail 3 to lock the upper and lower rails 4 , 3 relative to one another.
The elastic flange portions 15 of the upper rail 4 face towards and are always in contact with the respective surface portions 14 of the lower rail 3 . It is to be understood that the surface portions 14 are not limited to the shape and configuration shown in FIG. 1 . The surface portions 14 can be in a variety of other configurations, including a surface having arc-shaped regions or reverse V-shaped regions. The surface portions 14 forming projection portions preferably contact the respective flange portions 15 along several spaced apart line contacts or several spaced apart point contacts.
When the lock mechanism 7 is disengaged from the holes 6 of the lower rail 3 by operating the handle 5 , the upper rail 4 is free to move relative to the lower rail 3 and the driver can thus adjust the seat to any preferable position. Rattling is prevented during sliding movement of the seat or under vehicle vibration conditions because the flange portions 15 of the upper rail 4 elastically contact the respective surface portion 14 of the lower rail 3 that is provided with the projections. In addition, the sliding movement between the steel and light weight metal alloy material avoids sticking between the two parts and also reduces the sliding resistance. Moreover, abrasion powder generated by the frictional contact of the light weight metal alloy material is able to enter the bottom of the surface of the indented regions or grooves of the surface portion 14 , thus avoiding interference with the siding surface. It is thus possible to achieve a relatively constant sliding resistance. It is also to be understood that the convex portion(s) or projections forming the surface portion 14 can also be made separately from the lower rail 3 and then subsequently fixed to the side portions 10 of the lower rail 3 .
The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.
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A seat slide apparatus includes an upper rail smoothly slidable relative to a lower rail without using any balls. A part of the convex portion of the lower rail made of lightweight metal alloy material contacts the flange portions of the steel-made upper rail with an elastic spring force.
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FIELD OF INVENTION
The invention relates to fishing lures and particularly to the type of fishing lure having a main line which extends through the body of a primary lure adapted to slide on the line and also relates to lure assemblies incorporating both a primary lure and a secondary lure.
BACKGROUND OF INVENTION
It has previously been known to provide fishing tackle having a lure and a main line that extends through the body of the lure and permits the lure to slide on the line under certain conditions. Examples of such lures are found in U.S. Pat. Nos. 1,972,697; 2,112,901; 2,494,407; 2,609,633 and 2,794,288, it has also been known to provide a fishing lure assembly having a primary lure and a secondary lure such as shown in U.S. Pat. No. 2,794,288. However, what has not been heretofore achieved and which becomes the object of the present invention is to provide a fishing lure assembly having a main line mounting a primary lure which can slide back and forth on the line, an associated secondary lure and a unique combination of features which permit the primary lure and associated secondary lure to (a) be easily cast together; (b) the primary lure to produce an intermittent or popping sound for attracting fish; (c) provide both a surface and a subsurface lure; and (d) utilize the primary lure in a manner such that it can be used as a strike indicator, alternatively as a depth control or in combination with a skirt solely as a surface or so-called top water lure.
SUMMARY OF INVENTION
The fishing lure assembly of the invention comprises a floatable plug simulating in shape and color a small bait size fish serving as a primary lure through which the main line extends in slidable relation substantially along the central longitudinal horizontal axis thereof. The primary lure transports a hook structure and is shaped at its forward end to produce an intermittent or popping sound when pulled through the water. The trailing end of the main line in the principal first embodiment mounts a secondary lure comprising a lightweight spoon at the outer end of which is mounted another hook structure. In a second embodiment, a bead and split ring are mounted on the trailing end of the line which permits mounting of a skirt as a secondary lure immediately behind the primary lure and in a third embodiment a propeller is mounted at the rear of the primary lure to accent fish attraction produced by the primary lure. The primary lure is thus versatile and is designed in such a way that it can be used with a variety of fish attracting devices such as the mentioned spoon, skirt or propeller.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a first embodiment of the invention in use illustrating how the spoon, i.e. the secondary lure, tends to sink relative to the surface plug, i.e. the primary lure after the lures have been cast.
FIG. 2 illustrates a side view of the plug which serves as the primary lure and showing the main line fitted with a split ring to act as a stop.
FIG. 3 illustrates a front end view of the plug of FIG. 2.
FIG. 4 illustrates a cross section taken along line 4--4 of FIG. 3
FIG. 5 is a perspective view of the plug of FIG. 2.
FIG. 6 illustrates the plug of FIG. 2 fitted with a bead and split ring and skirt.
FIG. 7 indicates the lure assembly of FIG. 1 in use and with the plug serving as a strike indicator.
FIG. 8 illustrates the plug of FIG. 2 fitted with a propeller.
FIG. 9 is a side elevation view of a spoon as used in the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
Making reference initially to FIGS. 1-5, the fishing lure assembly 10 of the invention provides a primary lure simulating a small, suitably colored fish approximating the size of the typical minnow used for bait comprising a plug 12 made of a floatable wood, plastic or other material having a simulated open mouth with jaws 15 formed with a recessed, relatively shallow, cavity 16 which has been discovered to produce a desirable, fish attracting, intermittent or popping sound in use. Plug 12 has a relatively smooth, rearwardly tapered shape devoid of fins or the like, is of a solid construction, and cross-sections at any location along the length of the plug are generally circular and centered on the central longitudinal, horizontal axis of the plug.
Simulated fish eyes 13 are mounted on an upper surface of the plug immediately behind the upper of the jaws. The main line 17 leading from the rod-reel assembly 19 held by the fisherman F passes through a central opening or bore 18 substantially coinciding with the central longitudinal horizontal axis of lure 12. A set of hooks 20 are fitted outwardly and beneath plug 12 intermediate the length thereof. A conventional concave, lightweight metal formed spoon 22 forms a secondary lure and is secured to the outer end of the main line 17. Another hook structure 25 is loosely mounted on the outer or trailing end of spoon 22. Thus, after the line assembly 10 has been cast, there is provided both a surface and a subsurface lure and an intermittent or popping sound is produced as plug 12 is pulled through the water.
Prior to casting, the lures are assembled as illustrated and the fisherman F brings the primary lure or plug 12 in close relation with the secondary lure or spoon 22 such that they may be cast together. After the initial cast, the spoon 22 tends to sink as in FIG. 1 and thus there is quickly established both a surface lure provided by plug 12 and a subsurface lure provided by spoon 22.
In use, the lure 12 floats and when a fish is caught by the secondary lure immediately tilts and thus acts as a strike detector as seen in FIG. 7. After being cast, the line 17 to which the spoon 22 is attached, tends to assume a roughly 45° angle X with respect to the water surface S.
Depth control can be achieved by installing a stop 30 on the main line 17 as in FIG. 2. The flexible hub portion 34 of a conventional rubber or plastic formed skirt 35 can be installed over a bead, not shown and hidden from view in FIG. 6, and split ring 39 as in FIG. 6. Further versatility is exhibited by the ability to use plug 12 with a propeller 31 mounted between a pair of beads 37, 37' and secured by a split ring 41. Propeller 31 revolves when plug 12 is pulled through the water and in conjunction with the sound produced by plug 12, further attracts the fish being sought.
In summary, the following advantages are achieved in conjunction with providing the intermittent or popping sound:
(a) A secondary lure of any normal weight used in fishing can be delivered at any of any infinite number of depths.
(b) The primary lure can serve as a strike indicator for the secondary lure.
(c) The primary lure does not restrict the ability to set the hook on the secondary lure.
(d) The primary lure acts as an attraction to the secondary lure.
(e) Each cast presents two entirely different lures to the fish at the same time.
(f) Fish searching is enhanced by the presence of both a primary and a secondary lure.
(g) In a schooling fish situation, the opportunity for catching two fish simultaneously is enhanced.
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A fishing lure assembly provides a primary surface type lure formed so as to be able to slide on the fishing line on which it is mounted and a secondary subsurface type lure secured to the end of the line. Various modifications permit the primary line to mount various fish attracting devices.
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FIELD OF THE INVENTION
The invention relates to an apparatus for applying partial surface coatings to textile substrates, particularly adhesive materials in insert fixing technology in which a flowable thermoplastic or thermosetting plastic coating compound is applied to the substrate and is made to firmly adhere thereto.
BACKGROUND OF THE INVENTION
Numerous processes are known for the coating of textile substrates, e.g. non-woven fabrics, fabrics and gauze materials. Most of the coating compounds are adhesive compounds, which are applied for the firm joining of a substrate to the coated substrate in the adhesive state or are made adhesive after application, the adhesive compound being brought into a stable state after adhesion has taken place. High demands are made on such joints in the textile industry with respect to the binding strength, the durability, lack of sensitivity to external influences and elasticity and these are fulfilled to a varying extent by the known processes, as will be shown hereinafter.
The known foil coating in which a separately produced foil of thermoplastic material is pressed onto a preheated textile substrate or an extruded foil is applied in the still warm state to the substrate and is pressed onto the latter, as well as surface coating in which a thermoplastic powder mixed to form a paste is scraped onto a textile web, dried, heated and adhered to the substrate in the slightly liquid state by roller pressure are only used to a limited extent in the textile field, because continuous, uninterrupted thermoplastic coatings during the subsequent adhesion to other textile substrates through temperature, time and pressure have excessive thermal and washing shrinkage values particularly for the clothing industry and also give the end product a non-textile feel.
In the known sprinkling or dusting process, a thermoplastic coating material preground or screened out to a particular particle size distribution is sprinkled onto a preheated textile web, further heated in an oven and then firmly adhered to the textile substrate in the slightly liquid state by roller pressure. As such coatings are irregular, substrates coated in this way after adhering to other thin, smooth upper-materials conventionally used especially in the shirt and blouse industry lead to an orange skin-like surface of the article of clothing following a cleaning treatment.
In the net coating process, an extruded net or a longitudinally slotted foil is spread out and adhered to the preheated textile web. When the stretched net is heated, the connection points tear and the now projecting extensions draw back again into the intersections of the net, so that a non-continuous, punctiform coating of excellent regularity is obtained, but this process is little used because it is uneconomic.
The regular partial, e.g. punctiform coating of the substrate with an adhesive material represents an essential requirement of the clothing industry, obviously whilst respecting the aforementioned requirements. Various processes are known for this. Rotary screen process printing is very widely used in which thermoplastic powder mixed to form a paste by means of binders is applied by a doctor blade with the desired opening pattern to the substrate through the openings of a cylinder screen printing block moving along the substrate. After drying the binder, the thermoplastic material is partly melted and joined to the substrate by roller pressure. This process is also known in conjunction with the use of a ground thermoplastic adhesive material, but the same uniformity as obtained in the processing of pastes is not achieved. The end product is in fact similar to that obtained with the sprinkling or dusting process and has the same disadvantages.
The known intaglio printing-based processes are very economic. Such processes have proved advantageous in connection with the use of a thermoplastic powder, which is scraped onto a roller having depressions arranged in the desired way. A preheated textile web receives the powder, which is further heated in a continuous heating furnace and then firmly adhere to the substrate by roller pressure.
All the known processes function with thermoplastic materials ground and/or screened to particular particle sizes, which is expensive.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an apparatus for practicing; a process of the aforementioned type so that the coating compounds can be applied from materials in their original and generally granular form, i.e. do not have to be ground and/or screened, whilst still permitting a perfect partial surface coating of the substrate, without having to accept limitations with regards to the arrangement and form of the coating.
In accordance with one embodiment of the invention this object is achieved by an apparatus for applying partial surface coatings to textile substrates, particularly adhesive compounds, which employs a rotatable metal cylinder having inner and outer cylindrical surfaces having perforations extending therethrough from said inner surface to said outer surface and being rotatable about a longitudinal axis. A coating head is mounted inside the cylinder and has at least one coating nozzle adjacent and facing the inner surface. The coating head is a beam extending parallel to said axis and includes a feed duct, a main duct extending from the feed duct and an opening chamber extending from the main duct. The opening chamber is bounded by two sealing lips adapted closely to the inside of the cylinder, supported by mounting means on the coating head and defining an outlet opening therebetween for the controlling flow from opening chamber.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings which form a part of this disclosure:
FIG. 1 is a schematic, block diagram of a system for applying thermoplastic and thermosetting plastic compounds to textile substrates according to a first embodiment of the present invention;
FIG. 2 is a schematic, block diagram of a system for applying thermoplastic and thermosetting plastic compounds to textile substrates according to a second embodiment of the present invention;
FIG. 3 is a diagrammatic, side elevational view of an apparatus for applying coating compounds according to a first embodiment of the present invention;
FIG. 4 is a diagrammatic, side elevational view of an apparatus for applying coating compounds according to a second embodiment of the present invention;
FIG. 5 is a diagrammatic, side elevational view of an apparatus for applying coating compounds according to a third embodiment of the present invention;
FIG. 6 is an end elevational view of a coating head according to the present invention;
FIG. 7 is a diagrammatic, side elevational view of an apparatus for applying coating compounds to textile substrates according to a fourth embodiment of the present invention;
FIG. 8 is a partial, enlarged, elevational view of the coating head of FIG. 7;
FIG. 9 is a partial, enlarged view of a portion of the apparatus of FIG. 7; and
FIG. 10 is a partial, side elevational view, in section, of the adjacent ends of the coating head and perforated cylinder of the apparatus of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The coating installation shown in block diagram form in FIG. 1 is used for applying a thermoplastic melting substance and comprises a container 1 for receiving, storing and liquifying the substance. Such equipment is known (DAS No. 2,836,545) and will not be described in greater detail here. The coating installation also comprises a line 2 connecting container 1 with a conveying mechanism 3, which conveys the melting substance through the coating installation. The conveying or transporting mechanism 3, e.g. a volume-type pump is mechanical, e.g. is connected by a shaft 4 to a motor drive 5. The coating installation also comprises a coating head 6 with a coating nozzle 8 connected by means of a line 7 and which by means of a line 9 is connected to the conveying mechanism 3. By means of a mechanical connection 11, coating head 6 is connected to a motor drive 10. Part or all the coating head 6 is moved by drive 10, e.g. by laterally displacing head 6 with respect to the substrate movement or by rotating part thereof, of FIGS. 6 and 7. A control 12, whose instructions are supplied by lines 13, 14 to motor drives 5, 10, is associated with the coating installation.
FIG. 2 shows a coating installation in partial block diagram form. The difference between this installation and that of FIG. 1 is merely with regards to the arrangement of motor drive 10, connected by mechanical connections 11, 16 both to coating head 6 and to coating nozzle 8. In this case, as required, coating nozzle 8 can be moved alone or together with coating head 6. In FIGS. 1 and 2, drive 10 is responsible not only for the movement of the complete coating head 6, but also for the movement of all parts required for applying the coating compound, e.g. valves, switches for heating systems and the like. The mechanical drive can naturally be replaced by an equivalent hydraulic, pneumatic or electric drive.
The coating installations according to FIGS. 1 and 2 are suitable not only for the application of thermoplastic coatings, but also for thermosetting plastic coatings, it being optionally necessary to carry out certain modifications on some devices. However, in general, these installations have the advantage that they have a simple construction and do not require ground powder. Instead, they can use granular material, but still obtain uniform coatings.
The installations shown diagrammatically in FIGS. 3 to 5 illustrate the overall arrangement for the continuous application of partial coatings to a textile web or to cut portions transported on a substrate. The same reference numerals designate the same parts as in FIGS. 3 to 5.
The textile substrate 15 is unwound from an unwinding device 16, passes through a preheating zone 17 and reaches a first station 18 (FIG. 3), where one side of the substrate is indirectly coated, i.e. the coating compound is supplied through line 9, e.g. a heated hose, to coating head 6 with coating nozzles 8 and is applied to a roller 19 which, as a function of the desired partial coating, has corresponding surface characteristics and transfers the applied coating to substrate 15. A counter-pressure roller 20, also having different coating characteristics, cooperates with roller 19 for the purpose of calendering the application coating. Behind the first station 18 is arranged a second station 21 with the same construction and is used for providing a second indirect coating application to substrate 15, so that now the complete partial coating is applied. Obviously, the number of stations used is dependent on the nature of the partial coating and it is possible to have one, two or more stations 18 to 21.
Following station 21, the textile substrate 15 passes into a heated continuous passage section 22 for further melting of the thermoplastic materials or for drying or condensing out the coating compound. After passing through the heated section 22, there is a further calendering by a calender 23 with rollers 24, 25 for improving the adhesion of the coating compound to the substrate 15, after which it is wound up onto a winding-on device 26.
The temperature in preheating zone 17 is adjustable in such a way that the textile substrate 15 can be preheated to ensure a completely satisfactory transfer from roller 19 to substrate 15 or, in the case of direct application, from coating nozzle 8 to substrate 15. As a function of the substrate 15 to be processed, calender 23 can also be omitted if calendering in stations 18, 21 ensures a reliable adhesive of the coating to the substrate surface.
The installation according to FIG. 4 is used for the direct application of the coating compound to substrate 15, i.e. the coating compound is applied to substrate 15 in a coating station 27 via line 9, coating head 6 and coating nozzle 8. The coating compound is then further heated in the continuous passage section 22 and then calendered in calender 23. In station 27, a base 28 is arranged below substrate 15 and is either stationary or moves with the said substrate.
FIG. 5 shows a lining or backing installation, i.e. for sticking together textile substrates 15 or 15'. In a lining station 29, the adhesive compound is directly applied to substrate 15. Adhesion to the second substrate 15' then takes place between a roller 30 and a counter-pressure roller 31. Following further heating in the continuous passage section 22, calendering takes place in calender 23. In the lining station 29, roller 30 together with a further roller 32 also serve for the guidance of a belt 33 over the fixed base 28. Belt 33 moves at the same speed as substrate 15.
FIG. 6 shows a coating head 6 having a connecting piece 35 on one outside wall 34 and to which is connected line 9 (not shown). On a further outer wall 36 is provided the coating nozzle 8. Casing 37 of coating head 6 contains a rotary slide valve 38 with depressions 39, through which the coating compound is intermittently supplied to coating nozzle 8, which is supplied through a line 40 to depressions 39 and then through a line 41 to coating nozzle 8. Rotary slide valve 38 permits an accurate dosing of the coating compound leaving nozzle 8. Coating head 6 can coprise one, two or more coating nozzles 8. As a function of the number of nozzles 8, the casing and slide valve 38 has a corresponding length. In FIG. 6, dosing takes place in a regular manner, but it is also possible for dosing to take place at irregular intervals enabling different application effects and/or rigidities to be obtained, which can be further increased by different depressions 39. If, in addition, coating head 16 is pivotably arranged in a plane parallel to the substrate plane, it is possible to vary the spacing between the individual coating nozzles 8 by the sloping arrangement of head 6 with respect to the direction of movement of substrate 15. In this way, it is possible to obtain very closely juxtaposed partial coatings, which would not be possible due to the necessary spacing between two nozzles 8 in the case of a coating head 6 arranged perpendicular to the substrate movement.
Interrupted application to substrate 15 can also be obtained by means of controlled valves. Hydraulic, pneumatic, electric or mechanical energy can be used for operating these valves. There is also a considerable number of valves when using a relatively large number of juxtaposed nozzles 8. In this case, the rotary slide valve 38 can lead to the same action as with a larger number of valves. As thermoplastic and in part thermo-setting plastic compounds have a lubricating action, the rotary slide valve 38 leads to the same operational reliability as with individual valves. In addition, the surface of slide valve 8 and the bore of casing 37 can undergo surface treatment, e.g. siliconization, chromium plating, etc. If a plurality of juxtaposed valves 38 are used, they can move at different speeds to achieve different coatings.
Further coating effects can be obtained through the design of coating nozzles 8. By varying the width, size and shape of the nozzle ends, it is also possible to obtain different coating effects. This is particularly advantageous if different stiffening effects are to be obtained on the substrates 15 to be treated.
Heating in preheating zone 17 and in continuous passage section 22 can take place in different ways, e.g. by electric heating, infrared heating and heating by a hot air blower. Substrate 15 must be unrolled and rolled up again as carefully as possible in order to prevent any distortion thereof.
It is admittedly possible to obtain a large number of partial coating patterns with the nozzles 8 arranged in coating head 6, but due to the dimensions of the nozzles difficulties can be encountered in the production of closely juxtaposed coating portions. Admittedly, an improvement can be obtained by the aforementioned pivoting of the coating head 6 about a vertical axis, but in this case an additional adjusting device must be provided not only for coating head 6, but also for the support 28 positioned below the textile substrate 15. These difficulties can be eliminated by the coating installation according to FIGS. 7-10 in which coating is performed on the one hand with a coating head 6, e.g. according to FIG. 4 and on the other with a coating head 50 arranged within a rotating, perforated metal cylinder 46, where the pressurized melting compound is applied from a coating nozzle 49 to the inside of the metal cylinder 46 and from there through the perforations. In the case of both devices, application of the melting compound can take place indirectly via a transfer belt or a transfer roller or directly to the textile substrate 15. FIG. 7 illustrates the indirect application of the melting compound to a carrying belt 45, e.g. a PTFE belt in connection with a coating head 6 provided with not shown nozzles and said belt transfers the compound to substrate 15. In connection with the application with metal cylinder 46, it is possible to use both direct and indirect applications by means of a transfer roller 51 to textile substrates 15. In the case of direct application, there is no need for the carrying belt 45. When using coating head 6, indirect application via belt 45 offers the advantage that by pivoting coating head 6 about a vertical axis the distance between the nozzle ends can be reduced. In this case, the bearing arm 47 arranged on the other side of carrying belt 45 must also be pivotable.
In the case of perforated metal cylinder 46, there is no need for carrying belt 45, because in cylinder 46 the perforations can be arranged as close to one another as required. In the case of the indirect application of the melting compound, a treated transfer roller 51 is provided and serves to transfer the compound to substrate 15. In the case of a direct application of the melting compound, a heated acceptance or take-over roller 52 is used and there is then generally no need for transfer roller 51. If carrying belt 45 is used for the indirect application of the melting compound, the transfer roller 51 is used as a drive roller for belt 45.
Substrate 15 is unwound from a unwinding device 16 and passes via a guide pulley 53 onto a preheating roller 54 and from there to acceptance roller 52, where the melting compound is applied either directly or indirectly. The partially coated substrate 15 passes through a calender having two coolable calender rolls or bowls 55, 56, provided with an adjustable bowl gap, cf arrow 57. After calendering the substrate 15 passes via two cooling rollers 58, 59 and a guide pulley 60 to a winding-on device 61 onto which it is wound by a winding drive 62.
A further substrate 15 is unwound from a further unwinding device 63, guided via a guide pulley 64, a preheating roller 65 and a calender bowl 56 and is lined with the substrate coated with the melted compound. Both coating and lining can take place with the present installation. The different rollers are driven by a motor drive 66, which guides rollers 57, 58, 59 by means of an envelope member 67, e.g. an open-link chain and by gears indicated by the dot-dash line. Envelope member 67 also drives a diagrammatically shown gear 69, which in turn drives rollers 52, 55, 65, optionally by means of intermediate gears. In turn, rollers 52, 55 drive rollers 51 or 57. Carrying belt 55 is driven by transfer roller 51 and is tensioned by a gripping device with a gripping wheel 70. Guide pulleys 71, 72 guide carrying belt 45.
Cylinder 46 can have random perforations, e.g holes, slots, etc in the most varied arrangements, sizes and shapes.
The dosing of the melting compound can take place by pressure in the compound supply, the size of the perforations in cylinder 46, the width of the opening between sealing lips 82 and the substrate drive. The coating head 50 with its cylinder 46 extends over the width of the machine or acceptance roller 52, cf arrow 73, which is also used for adjusting the roller gap of transfer roller 51. Coating head 50 is a beam with a cavity located in its interior comprising a feed-in duct 79, a main duct 80 having a slot or juxtaposed slots and an opening or issuing chamber 81. Chamber 81 is bounded by two sealing lips 82 forming an opening or gap. As feed-in duct 79 and main duct 80 do not extend up to the end faces of the beam, it is merely necessary to laterally seal opening chamber 81. This is effected by two rods 90 attached to the sealing lips and adjustably coupled to coating head 50, which follow the profile or chamber 81 and can also be used for adjusting the width of the opening of chamber 81, either through using varyingly long rods or by making the rods displaceable. The material of the rod is slightly deformable, e.g. in the form of a suitable plastic or a hose, so that on placing the beam on perforated cylinder 46, the sealing lips 82, e.g. of plastic or metal, can adapt closely to the inside of cylinder 46. Ducts 83 also extend over the length of the beam and into these can be inserted heating elements enabling a precise temperature to be respected and set.
Cylinder 46 is rotated by a not shown variable speed drive. The melting compound is supplied under pressure to the internal coating head 50 and is transferred to substrate 15 by the opening formed in front of sealing lips 82 and the perforations in cylinder 46. The melting compound is heated to a flowable state in a storage container and its temperature is regulated by a further heat supply up to an in coating head 50. The temperature can be additionally influenced by infrared radiation sources 77 external to the outer circumference of cylinder 46.
In order to permit a clean breaking off of melting compound on passing out of the perforations of cylinder 46 hot air, whose pressure and temperature can be adjusted, can be blown through the nozzles 78, e.g. in the vicinity of the raising point of cylinder 46 from substrate 15. The plant shown in FIG. 7 can be simplified in that the melting compound is only applied in acoordance with one coating type and the lining device can be omitted.
As a use, reference is made to the production of spun non-woven fabrics from thermoplastic adhesive fibres, which have hitherto been produced from slitted foils, but only accompanied by lining with prepared, e.g. siliconized paper could they be cut to the desired sizes in order to prevent sticking together by the blade temperature produced at the time of cutting. The aforementioned coating modes make it possible to produce spun non-woven fabrics in a simple way. The subsequent separation into strips can be avoided by interrupting the application in the fabric. This obviates the need for expensive intermediate layers. It is possible to pass equally quickly to some other application type, independently of whether continuous or discontinuous coating forms are involved.
The plant according to FIGS. 7-10 is mainly used for adhering textile substrates with a thermoplastic adhesive, but it is also possible to apply other agents, e.g. stiffening agents. The plant can also be used without difficulty for the application of thermosetting plastics.
EXAMPLE
Coating takes place on a textile or non-textile web of e.g. 120 g/m 2 of non-woven fabric for clothing inserts using 19 g/m 2 of polyamide and a coating head according to FIG. 8 and a perforated cylinder in a 17 mesh arrangement (arrangement of the points on an equilateral triangle with angles of 60°), in order to permit subsequent sticking to the back for reinforcement purposes with upper-material in the clothing industry on the generally known splicing or pasting presses at 150° C., 300 to 3500 g pressure/cm 2 and for 12 to 15 seconds.
The following compounds are used as coating materials for the partial coating of textile substrates with thermoplastic adhesives: ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, polystyrene-butadiene-polystyrene block polymers, polystyrene-isoprene-polystyrene block polymers, polyethylene, polypropylene, butyl isobutyl and isoprene rubber types, ethylene propylene rubber, polyvinyl acetate and polymers thereof, saturated polyesters and copolyesters, polyurethanes, polyamides and copolyamides.
The thermosetting plastics used, e.g. phenol and cresol resins, as well as epoxy resins, are applied in liquid form and after hardening form brittle, pressure-resistant materials. Prior to cross-linking, up to 60% of fillers can be admixed therewith.
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
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Apparatus for applying partial surface coatings to textile substrates, particularly adhesive compounds in fixing inset technology. A cylinder rotatable about a cylindrical axis has inner and outer cylindrical surfaces with perforations extending through these surfaces. A coating head mounted inside the cylinder has a coating nozzle adjacent and facing the inner surface. The head includes a feed duct, a main duct extending from the feed duct and an opening chamber extending from the main duct. The opening chamber is bounded by two sealing lips adapted closely to the inside of the cylinder, supported by a mounting structure for the chamber and defining an outlet opening therebetween for controlling flow from the chamber. The structure has rods attached to the lips and adjustably coupled to the coating head to enable the opening to be adjusted in width.
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BACKGROUND OF THE INVENTION
In the drilling of wells into the earth by rotary drilling techniques, a drill bit is attached to a drill string, lowered into a well, and rotated in contact with the earth; thereby breaking and fracturing the earth and forming a wellbore thereinto. A drilling fluid is circulated down the drill string and through nozzles provided in the drill bit to the bottom of the wellbore and thence upward through the annular space formed between the drill string and the wall of the wellbore. The drilling fluid serves many purposes including cooling the bit, supplying hydrostatic pressure upon the formations penetrated by the wellbore to prevent fluids existing under pressure therein from flowing into the wellbore, reducing torque and drag between the drill string and the wellbore, maintaining the stability of open hole (uncased) intervals, and sealing pores and openings penetrated by the bit. A most important function is hole cleaning (carrying capacity), i.e. the removal of drill solids (cuttings) beneath the bit, and the transport of this material to the surface through the wellbore annulus.
Reduced bit life, slow penetration rate, bottom hole fill up during trips, stuck pipe, and lost circulation, can result when drill solids are inefficiently removed in the drilling of vertical boreholes. The efficiency of cuttings removal and transport becomes even more critical in drilling the deviated or inclined wellbore, particularly when the inclination is greater than 60 degrees, because as cuttings settle along the lower side of the wellbore, this accumulation results in the formation of a cutting bed. As a result of the reduction in net area open to flow, cuttings transport becomes severely impaired. If the drill pipe lies on the low side of an open hole interval (positive eccentricity), drill solids concentrate in the constricted space and conditions susceptible to differential sticking of the pipe can also occur. Hole cleaning can also be a problem under conditions where the drill string is in tension and intervals of negative eccentricity result as the drill string is pulled to the high side of the annulus. In the latter situation, the drill string is not usually in direct contact with the cuttings bed, but the latter's presence can lead to incidents of stuck pipe when circulation is stopped to pull out of the hole.
Various methods have been proposed for improving the efficiency of cuttings removal from the wellbore, including, promoting the formation of a particular flow regime throughout the annulus, altering the rheology of the entire drilling fluid volume, increasing the annular velocity, rotating pipe, and combinations thereof. In the case of the inclined wellbore, U.S. Pat. No, 4,246,975 to Dellinger, teaches the use of eccentric tool joints to stir up the cuttings bed, thus aiding cuttings removal.
U.S. Pat. No. 4,361,193 to Gravley teaches the incorporation of one or more fluid nozzles in the drill string for directing a portion of the drilling fluid circulating in the drill string outwardly into the annulus of the wellbore about the drill string so as to effect a stirring action on the drill cuttings and improve their removal by the return flow of the drilling fluid.
SUMMARY OF THE INVENTION
The present invention is directed to a method and system for increasing the cuttings transport efficiency during the rotary drilling of a wellbore. A drill string is formed of a plurality of sections of drill pipe interconnected at tool joints with a drill bit at its lower end. A drilling fluid is circulated down the drill and up the annulus between the wellbore and the drill string. As the drilling fluid is circulated, it flows through a plurality of annulus reducers located at spaced-apart positions along the drill string. The annulus reducers impart a cyclical pumping action to the flowing drilling fluid. During drilling, the drill string is axially reciprocated. An extension capability of the drill string maintains continuous weight on the drill bit during this reciprocating action.
In a further aspect, the annulus reducers provide for at least two differing sizes of annulus restrictions alternately spaced along the wellbore.
In a still further aspect, the reciprocating movement of the drill string is such that each annulus reducer is moved a distance at least equal to the axial spacing of the annulus reducers along the drill string.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a drill string lying along the lower side of a deviated wellbore extending into the earth.
FIG. 2 illustrates a cuttings bed buildup around the drill string of FIG. 1 during rotary drilling operations.
FIG. 3 illustrates the drill string of the present invention for use in the deviated wellbore of FIG. 1 to minimize a cuttings bed buildup.
FIGS. 4-6 illustrate alternate embodiments for the annulus reducers utilized with the drill string of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 there is illustrated a conventional drill string used in the rotary drilling of a wellbore, particularly a deviated wellbore. A deviated wellbore 1 has a vertical first portion 3 which extends from the surface 5 of the earth to a kick-off point 7 and a deviated second portion 9 of the wellbore which extends from the kick-off point 7 to the wellbore bottom 11. Although the illustrated embodiment shows a wellbore having a first vertical section extending to a kick-off point, the teachings of the present invention are applicable to other types of wellbores as well. For instance, under certain types of drilling conditions involving porous formations and large pressure differentials, the teachings herein may be applicable to vertical wellbores. Also some deviated wellbores need not have the first vertical section illustrated in FIG. 1.
A shallow or surface casing string 13 is shown in the wellbore surrounded by a cement sheath 15. A drill string 17, having a drill bit 19 at the lower end thereof, is positioned in the wellbore 1. The drill string 17 is comprised of drill pipe 21 and the drill bit 19, and will normally include at least one drill collar 23. The drill pipe 21 is comprised of joints of pipe that are interconnected together by tool joints 25, and the drill string may also include wear knots for their normal function. In the deviated second portion 9, the drill string normally rests on the lower side 27 of the wellbore.
Drill cuttings are removed from the wellbore bottom 11 by circulating drilling fluid, as shown by the arrows.
It is a common occurrence in the drilling of high-angle boreholes, as shown in FIG. 1, to have difficulty in removing the drill cuttings from the wellbore. A normal drilling mud circulation rate is about 100 feet/minute average velocity in the annulus between a 5 inch drill pipe and a nominal 121/4 inch wellbore. This velocity is frequently inadequate to remove the drill cuttings. By increasing the mud flow velocity to 150 feet/minute, cuttings removal has been found to be enhanced. However, problems are experienced at the greater flow rate. Pump pressures increase dramatically causing added expenditure of power and maintenance. The wellbore may not be able to support this increased pressure without breakdown of the formation and subsequent loss of drilling mud circulation.
Also, any decrease in the size of the annulus will cause both a pressure and velocity increase in the drilling mud flow. For example, the mud flow velocity of 100 feet/minute around the 5 inch drill pipe will increase to about 115 feet/minute about a 63/8 inch tool joint and to about 145 feet/minute about an 8 inch drill collar. In addition, if the 121/4 inch wellbore were reduced to 111/4 inch, the mud flow velocity would be about 123 feet/minute about the 5 inch drill pipe, 145 feet/minute about the 63/8 inch tool joint and 198 feet/minute about the 8 inch drill collar. These velocity changes are even more pronounced in drilling a 97/8 inch wellbore with 5-inch drill pipe.
To overcome such problems of drill cuttings removal in wellbore drilling operations, particularly in deviated wellbores, the present invention provides for the imparting of a cyclical pumping action into the drilling mud flow up the wellbore annulus. This pumping action provides a stirring of the cuttings which enhances their transport up the wellbore by the flowing drilling mud. This may be better understood by reference to FIGS. 2 and 3. Referring first to FIG. 2, it can be seen that in a deviated wellbore 30 each drill cutting particle 31 will tend to fall (as shown by arrow 32) from the flow of drilling mud up the wellbore (as shown by arrow 33). These particles accumulate on the lower side of the wellbore to form a cuttings bed as shown at 34 beneath and around the drill pipe 35 which also rests along the lower side of the wellbore on the tool joints 36.
Referring now to FIG. 3 there is diagrammatically shown the drilling tool of the present invention, the use of which provides a stirring action to the drill cuttings to keep them from falling out of the mud flow stream. At the lower end of the drill pipe 40 is the drill bit 41 and a conventional bottom hole assembly (BHA) 42 including the drill motor 53 and the measuring while drilling system 54. Adjacent the bottom hole assembly 42 is shown the extension sub 43 which provides the immediate source of weight on the drill bit. The drill pipe 40 may be cyclically moved up and down in the wellbore, to the extent allowed by the extension sub, without taking weight off the drill bit. Located at spaced-apart positions along the drill pipe 40 are a plurality of annulus reducers 44. These annulus reducers may be all of the same type or may be of different types at select spaced-apart positions along the drill pipe. FIG. 4 illustrates an annulus reducer 44 that is a drill pipe diameter enhancer wherein the mud flow cross-sectional area is reduced to the area 45 within wellbore 50. FIG. 5 illustrates an annulus reducer 46 that is a wellbore diameter reducer wherein the mud flow cross-sectional area is reduced to the area 47 within the wellbore 50. FIG. 6 illustrates an annulus reducer 48 that is a conventional drill pipe stabilizer wherein the mud flow cross-sectional area is reduced to the area 49 within the wellbore 50.
The drill tool of FIG. 3 is used to provide the desired stirring action to the drill cuttings in the following manner. During drilling operations, the drill pipe is cyclically moved up and down in the wellbore a distance d as permitted by the extension sub 43 which continuously maintains weight on the drill bit to advance the drilling operations. As the drill pipe is moved up and down the distance d, the annulus reducers 44 are also moved up and down the same distance d. It is preferable that the spacing between these annulus reducers be no greater than the distance d so that the up or down position of any one of such reducers overlaps with the down or up position respectively of an adjacent reducer. In this configuration, each axial movement of the drill pipe up and down in the wellbore cyclically causes the adjacent moving reduced annuli to overlap. The greater mud flow velocity through these moving reduced annuli imparts cyclical pumping action to the cuttings along the wellbore where the reduced annuli are located, thereby resulting in an enhanced transportion of the drill cuttings from the wellbore to the surface of the earth. Each of these stabilizers are supplied for varying wellbore size.
In one example, drill bit 41 is a 121/4 inch bit. Drill motor 53 is 73/4 inch Delta 1000 mud motor supplied by Dyna-Drill Co. of Irvine, Calif., and which is 241/2 feet in length. The measuring-while-drilling system 54 can be of the types supplied by the Anadrill/Schlumberger of Houston, Tex.; Gearhart Industries of Fort Worth, Tex.; Teleco Oil Field Services of Meriden, Conn.; or Exploration Logging of Sacramento, Calif., for example. Other suitable measuring-while-drilling systems are disclosed in U.S. Pat. Nos. 3,309,656, 3,739,331; 3,770,006; and 3,789,355. The spiral-bladed stabilizers 56 can be of the integral blade or non-magnetic integral blade type supplied by Norton Christensen, Inc. of Houston, Tex. or of the rig-replaceable sleeve type supplied by Drilco (Div. of Smith International) of Houston, Tex., for example.
Several alternative embodiments are available for configuration of the extension sub 43. When powered by hydraulic pressure, the teaching of U.S. Pat. No, 3,105,561 to Kellner for a hydraulic actuated drill collar may be utilized. The technology utilized in conventional bumper subs or jars for drilling and fishing operations may also be used. Numerous manufacturers supply such bumper subs or jars as listed in the Composite Catalog of Oil Field Equipment and Services, 36th Revision, 1984-85, published by World Oil, Houston, Texas. Such bumper subs include the lubricated bumper sub No. 746-23 of Baker Service Tools, the A-Z fishing bumper sub of A-Z International Tool Co., and the fishing bumper sub of Bowen and the ball bearing drive bumper jar of Driltrol as examples.
Several such annulus area reducers are supplied by Servco, Division of Smith International, Inc., Gardena, Calif., such as the sleeve-type stabilizer or the integral blade stabilizer.
Several types of annulus area reducers are available in the form of drill collar stabilizers, drill pipe stabilizers, integral blade stabilizers, sleeve stabilizers and spiral blade stabilizers. Numerous manufacturers supply such stabilizers as also listed in the Composite Catalog of Oil Field Equipment and Services, 36th Revision, 1984-85, published by World Oil, Houston, Texas. All of these stabilizers come in varying sizes for differing wellbore sizes. Such stabilizers include the clamp-on type stabilizer of Servco, a Division of Smith International, Inc., and the clamp-on and interchangeable sleeve stabilizers of SMF International, Paris, France as examples.
While a preferred embodiment of the invention has been described and illustrated, numerous modifications or alterations may be made without departing from the spirit and scope of the invention as set forth in the appended claims.
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A wellbore drill string is formed of a plurality of sections of drill pipe interconnected at tool joints with a drill bit at its lower end. A drilling fluid is circulated down the drill string and up the annulus between the wellbore and the drill string. A plurality of annulus reducers located at spaced-apart positions along the drill string impart a cyclical pumping action to the flowing drilling fluid. During drilling, the drill string is axially reciprocated and an extension capability to the drill string maintains continuous weight on the drill bit.
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FIELD OF THE INVENTION
[0001] This invention is directed to a method for repairing and reinforcing underground pipes, which does not require excavation to reach the section of pipe requiring repair and/or reinforcement.
BACKGROUND OF THE INVENTION
[0002] Underground pipes used for swimming pools, wells, sewers, other water systems and electrical cables can become cracked after many years of use. Such cracking can result from shifting of the earth, growth of roots, and placement of heavy objects on the ground above the pipes. If the pipe is a water supply or drain pipe, the cracking can cause water to leak from the pipe. If the pipe is used to house electrical cable, the cracking can cause water to leak into the pipe. In either case, the cracking can result in failure of the pipe for its intended purpose.
[0003] Repair of the damaged pipe can be accomplished by excavating the surrounding ground and repairing and replacing the damaged pipe or damaged sections of it. This process can be expensive and time consuming. An improved system and method for repairing and reinforcing underground pipes are disclosed in U.S. Pat. Nos. 7,137,757 and 7,241,076, both issued to Cosban, which are incorporated by reference. The disclosed system and method involve pulling a liner assembly through a length of the pipe and anchoring and sealing the liner assembly at both ends. The liner assembly includes a smooth flexible bore liner and a semi-rigid reinforcing helix that prevents or inhibits collapse of the liner within the pipe. Once the liner assembly has been pulled through the pipe and sealed at both ends, it functions as a new inner pipe wall which isolates the interior of the pipe from the cracks in the original pipe wall.
[0004] One drawback of the foregoing system and method is illustrated in FIG. 1 . In FIG. 1 , a liner assembly 10 including a smooth flexible bore liner 12 and a semi-rigid reinforcing helix 14 is being pulled through a pipe section 16 using a nylon cord 18 connected to a temporary liner head 20 . The pipe section 16 has a wall 22 that bends and defines a sharp inner corner 24 . As the liner assembly 10 is pulled through the pipe section 16 , the liner assembly 10 is urged against the sharp inner corner 24 of wall 22 . The semi-rigid helix 14 can become ensnared by the sharp inner corner 24 , causing the smooth flexible bore liner 12 to become punctured, torn or otherwise damaged, and sometimes causing at least a partial collapse of the liner assembly 10 . Even if the liner assembly 10 is not damaged, the sharp corner 24 can make it difficult or awkward to pull the liner assembly 10 through the pipe section 16 . The amount of drag or resistance when pulling the liner assembly 10 can become intolerable when there are multiple corners in the pipe being repaired and/or when the pipe and liner assembly are long.
[0005] There is a need or desire for an improved system and method for repairing and reinforcing underground pipes which overcomes the foregoing difficulty.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to an improved system and method for repairing and/or reinforcing underground pipes which minimizes and substantially reduces the resistance and drag encountered when moving the liner assembly through the pipe. The method includes the steps of providing a flexible liner assembly having a first end and a second end, applying an internal pressure to the liner assembly, inserting the first end of the liner assembly into a first end of a pipe section while maintaining the internal pressure, pushing the liner assembly through the pipe section while maintaining the internal pressure until the first end of the liner assembly reaches a second end of the pipe section, and releasing the internal pressure from the liner assembly. The method may include the steps of sealing the first and second ends of the liner assembly before pushing the liner assembly through the pipe section, to facilitate pressurization and maintain the internal pressure, and unsealing the first and second ends of the liner assembly to facilitate the release of internal pressure. The method may also include the step of connecting first and second ends of the installed liner assembly to the pipe section so that the liner assembly provides a substantially leak-free conduit through the pipe section.
[0007] The flexible liner assembly can include a smooth flexible bore liner and a semi-rigid reinforcing helix, and can be closed at both ends to maintain internal pressure. The flexible liner assembly can alternatively include another flexible material, such as a corrugated plastic material, which can be closed at both ends. The closure device can include a screw-in pressure plug at one or both ends which connects to an air compressor and transmits pressurized air to the interior of the liner assembly. Other types of closure devices can also be used.
[0008] The air pressure in the liner assembly should be high enough so that the liner assembly can be pushed through the interior or the pipe section without collapsing, and low enough that the liner assembly has sufficient flexibility to bend around the corners in the pipe section.
[0009] By providing a liner assembly that can be pushed through a pipe section, instead of being pulled, contact between the liner assembly and sharp corners of the pipe section can be generally avoided. The liner assembly does not become ensnared at the sharp corners, and less resistance is encountered when moving the liner assembly through the pipe section. This facilitates the repair of longer pipe sections, and pipe sections having a greater number of turns, than can be accomplished by pulling the liner assemblies through the pipe sections.
[0010] With the foregoing in mind, it is a feature and advantage of the invention to provide an improved method for repairing and reinforcing underground pipes which avoids or minimizes the problems associated with flexible liner assemblies becoming ensnared at the sharp corners of pipe sections.
[0011] It is also a feature and advantage of the invention to provide an improved liner assembly which can maintain internal pressure, enabling the liner assembly to be pushed instead of pulled through the pipe section.
[0012] The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the invention, read in conjunction with the accompanying drawings. The detailed description and drawings are intended to be illustrative rather than limiting, the scope of the invention being defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 schematically illustrates a prior art method of repairing or reinforcing an underground pipe that includes the step of pulling a liner assembly through a pipe section.
[0014] FIG. 2 schematically illustrates an inventive method of repairing or reinforcing an underground pipe that includes the step of pushing an internally pressurized liner assembly through a pipe section.
[0015] FIG. 3 schematically illustrates the use of a pig and a tag line to measure the length of a pipe section and determine the design length of a liner assembly to be inserted.
[0016] FIG. 4 is a perspective view of a screw-in end plug that can be attached to both ends of the liner assembly to maintain internal pressure during installation of the liner assembly into the pipe section.
[0017] FIG. 5 is a perspective new of the liner assembly of FIG. 4 with a gas injection nozzle attached, to inject pressurized gas such as air into the liner assembly.
[0018] FIG. 6 is a perspective view of an end cap for the liner assembly of FIG. 4 .
[0019] FIG. 7 is a top view of the liner assembly of FIG. 4 , further equipped with two small partial openings for receiving a special two-pronged tool.
[0020] FIG. 8 is a perspective view of one embodiment of a retainer sleeve that can serve as an adapter between one or both ends of the installed liner assembly and corresponding one or both ends of the pipe section.
[0021] FIG. 9 is a perspective view of an end of a pipe section with the retainer sleeve of FIG. 8 attached, and equipped with a threaded connector sleeve for connecting the pipe section to a main pipe or pipe assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to FIG. 2 , a pipe section 100 is shown having a first end 102 , a second end 104 , and a wall 106 having two sharp inner corners 108 . A flexible liner assembly 110 is provided including a first end 112 covered by plug 114 , and a second end 116 covered by plug 118 . The illustrated flexible liner assembly 110 includes a smooth flexible liner bore 120 and a semi-rigid reinforcing helix 122 . In alternative embodiments, the flexible liner assembly 110 may be formed of a corrugated semi-rigid plastic material, or another suitable material.
[0023] In order to repair or reinforce the pipe section 100 using the flexible liner assembly 110 , a selected pressure, such as air pressure, is applied internally in the liner assembly 110 . The internal pressure is large enough to maintain integrity and prevent collapse of the liner assembly 110 , but not so large as to prevent bending and flexing of the liner assembly 110 . The plugs 114 and 118 or other suitable means are employed to maintain the desired pressure inside the liner assembly 110 . The desired pressure inside the liner assembly 110 is generally about two (2) to about twenty (20) psi, suitably about three (3) to about six (6) psi. The optimum pressure may be different for different applications, depending on the length and diameter of the pipe section 100 , the length and diameter of the liner assembly 110 , the material of construction of the liner assembly 110 , the number of turns in the pipe section 100 , and other factors.
[0024] While maintaining the internal pressure, the first end 116 of the liner assembly 110 is inserted into the first end 102 of the pipe section 100 . The liner assembly 110 is then pushed through the pipe section 100 in the direction of the arrow until the first end 116 of liner assembly 110 approaches or reaches the second end 104 of pipe section 100 . As shown in FIG. 2 , because the pressurized liner assembly 110 is being pushed instead of pulled, the liner assembly 110 urges away from the sharp inner corners 108 of the wall 106 of pipe section 100 , and instead slides along the smoothly curved outer portions 109 of the wall 106 . There is little or no risk of liner assembly 110 becoming ensnared by the sharp inner corners 108 , and the liner assembly 110 passes through the pipe section 100 with minimal resistance.
[0025] The liner assembly 110 suitably has a predetermined length that is approximately equal to the length of the pipe section 100 being repaired or reinforced. This way, when the first end 112 of the liner assembly 110 approaches the second end 104 of the pipe section 100 , the second end 116 of the liner assembly 110 will approach the first end 102 of the pipe section 100 . Because the liner assembly 110 is flexible, it may have a length that is slightly longer or slightly shorter than the length of pipe section 100 . Suitably, the length of the liner assembly 110 , while internally pressurized, is within about 20%, or within about 10% of the length of pipe section 100 .
[0026] After the liner assembly 110 is fully inserted in the pipe section 100 , such that the first end 112 of the liner assembly 110 reaches the second end 104 of pipe section 100 , the internal pressure is released from the liner assembly 110 . This can be accomplished by removing the end plugs 114 and 118 from the liner assembly 110 . Before or after the internal pressure is released, the outer circumference of the first end 112 of the liner assembly 110 can be sealed to the inner circumference of the second end 104 of pipe section 100 , and the outer circumference of the second end 114 of the liner assembly 110 can be sealed to the inner circumference of the first end 102 of the liner assembly 110 . By virtue of the sealing, and the removal of end plugs 114 and 118 , the interior of the liner assembly 110 then functions as the interior of the pipe section 100 for purposes of passing fluids or storing electrical cable. The flexible liner assembly 110 provides a leak-free conduit, while the original pipe section 100 provides structural integrity.
[0027] The desired length of the liner assembly 100 can be determined by initially measuring the length of the pipe section 110 using a pig 130 attached to a tag line 132 as shown in FIG. 3 . Pig 130 can be made of polystyrene foam or another lightweight material, and has a cylindrical shape or other suitable shape that allows it to be transported through pipe section 100 using a blast of air from the first end 102 and/or vacuum from the second end 104 . The tag line 132 has a length at least as high as the length of pipe section 100 and can range from about 50 feet to several hundred feet. The pig 130 can be transported through the pipe section 100 in the direction of the arrow using a blow gun applied at the first end 102 and/or a wet/dry vacuum applied at the second end 104 . When the pig 130 reaches the second end 104 , the tag line 132 can be detached or left attached. The length of the tag line between the first end 102 and the second end 104 is then measured to determine the design length of the liner assembly 110 .
[0028] The pig 130 can alternatively be in the form of a wooden sphere, a plastic bag containing foam pieces, or another suitable material. When the pig 130 is formed as a wooden sphere, a fluid such as water can alternatively be employed to transport the pig 130 through the pipe section 100 . The length of pipe section 100 is typically the underground length, measured from a convenient entry point upstream from where the pipe section 100 enters the ground to a convenient exit point downstream from where the pipe section 100 leaves the ground.
[0029] When the liner assembly 110 is formed of a smooth flexible bore 120 and semi-rigid helix 122 , the smooth flexible bore 120 can be formed of polyamide, polypropylene, polyethylene, EPDM, nitrile, PVC/NBR (polyvinyl chloride/nitrile butadiene rubber) blends, or another suitable flexible material having good long-term stability during use. The semi-rigid helix 122 can be formed of polypropylene, polyethylene, wire reinforcement, or another suitable semi-rigid material. The semi-rigid helix 122 can be inside the flexible bore 120 , or may be external to the flexible bore 120 , in which case the flexible bore 120 is adhered to the semi-rigid helix 122 using heat or a suitable adhesive material. A commercially available material that combines the flexible bore 120 and semi-rigid helix 122 is sold by Kuryama of America, located in Schaumburg, Ill., under the trade name TIGERFLEX®.
[0030] The liner assembly 110 may alternatively be formed using a semi-rigid corrugated plastic material. Suitable plastic materials include without limitation polypropylene, high density polyethylene, polyamides, polyvinyl chloride, PVC/NBR blends, and laminates thereof. Other suitable materials and structures may also function as the liner assembly 110 , provided that the liner assembly 110 has sufficient flexibility to pass around corners in the pipe section 100 , and sufficient rigidity to avoid collapse.
[0031] The plugs 114 and 118 can be externally threaded plugs that screw into mating threads provided at the respective ends 112 and 116 of the liner assembly 110 to provide a substantially air-tight seal. FIG. 4 illustrates one embodiment of plug 114 or 118 , designated as a threaded plug 140 having an internally threaded opening 142 and external threads 144 . FIG. 5 illustrates the same plug 140 in which an injection nozzle 146 is connected to inlet 142 to permit the controlled injection of air from a pressurized air supply (not shown). FIG. 6 illustrates the same plug 140 in which a top cap 148 having a threaded portion 150 is screwed, pressure fitted, or otherwise sealed in the opening 142 . The top cap 148 optionally has a hook or loop 152 which can be connected to a tag line, as further explained below.
[0032] When the liner assembly 110 is being pressurized, prior to insertion into the pipe section 100 , a first plug 114 (represented by a combination of threaded plug 140 and end cap 148 ) can be screwed into the first end 112 of the liner assembly 110 with the aid of an epoxy or other sealant, if necessary, to provide a sealed fit. A second plug 118 (represented by a combination of threaded plug 140 and injection nozzle 146 ) can be screwed into the second end 116 of the liner assembly 110 with the aid of an epoxy or other sealant, if necessary. Air from a pressurized air supply (not shown) can be injected through nozzle 146 into the liner assembly 110 until a desired pressure is achieved. Then, the air supply is isolated and the injection nozzle 146 is removed from the second plug 118 and replaced with an end cap 148 .
[0033] At this point, the pressure inside the liner assembly 110 is maintained, and the liner assembly 110 can be inserted into the pipe section 100 by pushing from the second end 116 as described above. Alternatively, the liner assembly 110 can be inserted into the pipe section 100 using a combination of pushing from the second end 116 and pulling from the first end 112 . In order to perform the combination of pushing and pulling, the trailing end 131 of the tag line 132 shown in FIG. 3 can be tied or otherwise connected to the hook 152 of the end cap 148 on the first end plug 114 on the liner assembly 110 . This is accomplished before the liner assembly 110 is inserted into the pipe section 100 . Then, the liner assembly 110 can be inserted by pushing from the second end 116 , as explained above, and pulling from the first end 112 by pulling the leading edge 133 of the tag line 132 which can be connected to the pig 130 . Depending on the application, the pushing and pulling of the liner assembly 110 through pipe section 100 need not be performed simultaneously. In some applications, it may be desirable to perform an alternating sequence of pushing and pulling. In other applications, it may be desirable to continuously push from the second end 116 of the liner assembly and only occasionally pull from the first end 112 of the liner assembly. By designing the liner assembly 110 for both pushing and pulling, the user has the flexibility to perform whatever steps are necessary to successfully insert the liner assembly 110 into the pipe section 100 .
[0034] The plugs 114 and 118 can be formed of any suitable material such as polyvinylchloride, polypropylene, high density polyethylene or the like. The end plugs 114 and 118 are not limited to the foregoing configurations. Also, the tag line 132 should be formed of a material that is sufficiently strong to accommodate the liner assembly 110 , but does not cut and groove any portion of the wall 106 of the pipe section 100 . If the material of the tag line 132 is too sharp, it may cut and groove the sharp inner corners 108 , causing unwanted drag. One particularly suitable material for the tag line 132 is a flat nylon tape having a width of at least about 0.5 inch.
[0035] As illustrated in FIG. 7 , the top of the plug 140 may be designed with two small partial openings 141 and 143 that do not extend all the way through the plug 140 . The partial openings 141 and 143 are intended to accommodate a special two-pronged tool which facilitates the screwing and unscrewing of the plug 140 from the liner assembly 110 .
[0036] After the liner assembly 110 has been fully inserted into the pipe section 100 , the internal pressure is released by removing both end plugs 114 and 118 . If the threaded plugs 140 are used, they can be unscrewed with the aid of a two-prong tool that engages openings 141 and 143 . After the end plugs 114 and 118 are removed (or, in some instances, before), the outer surface of the end portions 112 and 116 of the liner assembly 110 can be fitted to the inner surface 109 of the pipe section 110 . Typically, the first end 112 of liner assembly 110 is fitted to the pipe section 100 near its second end 104 , and the second end 116 of liner assembly 110 is fitted to the pipe section 100 near its first end 102 .
[0037] In order for the installed liner assembly 110 to serve as a conduit within the pipe section 100 , it is important to provide leak-proof seals between the ends of the liner assembly 110 and the pipe section 100 . In most instances, the outer diameter of liner assembly 100 is slightly smaller than the inner diameter of pipe section 100 . In order to accommodate the differences in diameter, a retainer sleeve 160 , such as shown in FIG. 8 , can be provided at both ends 102 and 104 of pipe section 100 to serve as an adapter between liner assembly 110 and pipe section 100 .
[0038] The retainer sleeve 160 has a first portion 162 of narrower outer diameter, a second portion 164 of intermediate outer diameter, and a third portion 166 of wider outer diameter. The first portion 162 may or may not be threaded, and is adapted to engage the inner surface of liner assembly 110 at either or both ends 112 and 116 . The outer diameter of first portion 162 is about equal to the inner diameter of liner assembly 110 . An epoxy or other sealant can be applied to form an air and water tight, pressure resistant seal.
[0039] The second portion 164 may or may not be threaded, and is adapted to engage the inner surface of pipe section 100 at either or both ends 102 and 104 . The outer diameter of second portion 164 is about equal to the inner diameter of pipe section 100 at either or both ends. An epoxy or other sealant can be applied to form an air and water tight, pressure resistant seal.
[0040] The third portion 166 may or may not be threaded, and has an outer diameter about equal to the outer diameter of pipe section 100 at either or both ends. As shown in FIG. 9 , when the retainer sleeve 160 is fully installed, the third portion 166 may appear as a short extension of pipe section 100 at one or both ends 102 and 104 . The pipe section 100 can then be reconnected to the main pipeline or pipe assembly from which it was disconnected to initiate the repair or reinforcement. If the ends of the pipe section 100 are equipped with a standard threaded connector sleeve 170 having threads 172 , the connector sleeve 170 can be reconnected to a mating connector sleeve on the main pipeline or pipe assembly (not shown). The reconnection of mating connector sleeves further reinforces the position of retainer sleeve 160 at one or both ends of pipe section 100 . Sealing rings, such as O-rings, can also be used to reinforce the connection between connector sleeves 170 and mating connector sleeves.
[0041] The embodiments of the invention described herein are exemplary. Various modifications and improvements can be made without departing from the sprit and scope of the invention. The scope of the invention is indicated by the appended claims, and all changes that fall within the meaning and range of equivalents are intended to be embraced therein.
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A method of repairing or reinforcing underground pipes includes the steps of providing a flexible liner assembly having a first end and a second end, applying an internal pressure to the flexible liner assembly, inserting the first end of the liner assembly into a first end of a pipe section while maintaining the internal pressure, pushing the flexible liner assembly through the pipe section while maintaining the internal pressure, releasing the internal pressure from the flexible liner assembly, and connecting the first and second ends of the flexible liner assembly to the pipe section so that the flexible liner assembly provides a substantially leak-free conduit through the pipe section. The method addresses drawbacks associated with prior art methods by preventing or reducing contact between the flexible liner assembly and sharp inner corners of the pipe section, thereby reducing drag between the flexible liner assembly and the interior of the pipe section.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a device for measuring a gas flow, of the type having a measurement chamber and an ultrasonic transceiver unit which can be attached to the measurement chamber over the openings thereof and which is provided with transmit and receive heads which are oriented against the openings of the measurement chamber, with membranes being arranged between the measurement chamber and the transmit and receive heads which are permeable to ultrasound waves, but largely impermeable to moisture and bacteria.
2. Description of the Prior Art
German PS4 222 286 describes an ultrasonic flow meter of the above type in which the transmitter and the receiver are arranged at a distance from each other along a measuring tube. The measuring length extends obliquely to the axis of a tubular measurement chamber through which the medium flows whose flow rate is to be determined. This flow meter is known as a spirometer for determining the lung capacity of the patient. In order to maintain hygiene, a sterile insertion tube is inserted into the measurement chamber with each new patient. The sterile tube is provided with measurement windows which are fitted so that they are situated over the openings. Membranes which are permeable to ultrasound signals but impermeable to moisture and bacteria are arranged in the measurement windows, so that the ultrasound signals along the measuring tube can pass through the sterile insertion tube. It is therefore unnecessary for the hospital personnel to autoclave the flow meter after every use, which is advantageous since the ultrasonic transceiver unit, in particular, are sensitive parts in the flow meter. In connection with the known ultrasonic flow meer, the membranes, which are arranged at a distance from the ultrasonic transmit and receive heads, can be foam rubber, in one example, and a Mylar® film, in another. In connection with the first example, in order to be able to reach the transmit or receive unit, the ultrasound signals must first pass through the relatively thick foam rubber membrane, and then a relatively large air gap. This transition from a relatively thick membrane to a relatively large air gap can lead to a high acoustical impedance, i.e. to a high sound wave reflection. This can lead to relatively large acoustical losses, so that an unacceptably low sound signal reaches the transmit or receive heads. A relatively low acoustical impedance is associated with the use of a Mylar® film, due to its extreme thinness, so that a receivable sound signal can reach the aforementioned heads. The disadvantage of Mylar® films which are attached as described is that they are so thin and sensitive that they cannot always withstand the mechanical stress they are exposed to when a pressure excess arises in the measurement chamber, which can cause the films to easily rip.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a device of the type initially described wherein maximum acoustical energy is fed to the ultrasonic transceiver unit, while moisture and germs are kept away from the unit.
This object is inventively achieved in a device for measuring a gas flow the membranes are removably arranged close to the transmit and receive heads. Since the membranes are removable, they can be removed after an examination and replaced by new membranes in connection with a new patient. As an alternative, the membranes can potentially be cleaned and reused. Since the membranes are arranged close to the transmit and receive heads, the acoustical impedance is effectively lowered, and more acoustical energy is fed to these heads. Due to the placement of the membranes, very thin metal or polymer membranes can be used, for example, since they are no longer exposed to a mechanical stress in this position. A thicker membrane, made of foam rubber, for example, can now be used with nearly an equally good acoustical energy feed to the transmit and receive heads. The advantage of a thick membrane is its good durability.
The article "Impedance-Matched Metallurgically Sealed Transducers" (IEEE Transactions on Sonics and Ultrasonics, Vol. SU-31, No. 2, March 1984:101-104) teaches a robust ultrasonic sensor whose head is provided with a relatively thick membrane, which is connected to the sensor and which is permeable to ultrasound waves, but not to moisture and bacteria. In front of the membrane, a thin plastic film is attached which is provided exclusively to reduce the acoustical impedance, which is otherwise relatively high if a metal membrane as described is used. It is not stated in the article that the thin plastic film eliminates the possibility of moisture and bacteria reaching the metal membrane. Thus, despite the metal membrane and the plastic film, it is necessary when using this sensor in connection with an ultrasonic flow meter to autoclave this sensor prior to each new patient, since moisture and bacteria may be present on the metal membrane. Regular auto claving of the sensor results in a shortened lifetime.
In an embodiment of the inventive device, each transmit and receive head presses against the respective membrane. In such an embodiment, the membranes are fastened in the measurement chamber removably, for example. If the heads are pressed against the respective membranes, nearly all the air between the membrane and the head is pressed to the side, so that the heads become situated close to the respective membrane, thereby enabling a further reduction of the acoustical impedance.
In another embodiment of the inventive device, it is proposed that the membrane is attached to the transmit and receive head. The heads of the transmitter and of the receiver can thus be provided with membranes before being attached to the measurement chamber. Subsequent to the examination, the transmitter and receiver are detached from the measurement chamber, the membranes are replaced and the transmitter and receiver are used in connection with a new patient.
In another embodiment of the inventive device, each transmit and receive head is connected to the membrane by means of an adhesive, at least over a part of the head surface. The membrane is appropriately provided with an adhesive layer. The adhesive layer is removed from the head in the replacement of the membrane. Because the membrane has a mechanical connection to the head in this type of embodiment, the acoustical impedance is again lowered. There is mechanical stability of the membrane here as well.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the basic components of a first embodiment of an inventive measuring device, in a longitudinal section.
FIG. 2 shows the basic components of a second embodiment of inventive measuring device, in a longitudinal section.
FIG. 3 shows the basic components of a third embodiment of an inventive measuring device, in a longitudinal section.
FIG. 4 shows the structure of a part of a measuring device according to FIG. 3.
FIG. 5 shows the construction of the same part of the measuring device as in FIG. 4, but in another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically depicts an ultrasonic flow meter 1 wherein an ultrasonic transmitter 2 and an ultrasonic receiver 3 is and arranged along a channel 4, which serves as a measuring length, at a distance from one another. The channel 4 extends obliquely to the axis 5 of a tubular measurement chamber 6 through which the medium flows whose flow rate is to be determined. The flow meter is what is known as a spirometer for determining the lung capacity of the patient. The ultrasonic transmitter 2 and the receiver 3 are respectively provided with transmit and receive heads 7,8, which are directed toward respective openings 9, 10 in the measurement chamber 6 through which the measuring length extends. This general type of ultrasonic flow meter 1 is demonstrated and described in PCT Application WO 94/28790. Membranes 11, 12 are provided in the inventive ultrasonic flow meter 1 which are permeable to ultrasound waves but largely impermeable to moisture and bacteria and which are arranged close to the transmit and receive heads 7, 8. In this exemplary embodiment, the inner diameter of the channel 4 is approximately as large as the outer diameter of the transmit and receive heads 7,8. In this type of embodiment it is advantageous to attach the membranes 11, 12 directly to the transmit and receive heads 7, 8, respectively, with an adhesive, for example. The application of the metal or polymer membranes 11, 12 close to the respective transmit and receive head 7,8 results in a relatively low acoustical impedance, enabling a relatively large amount of acoustical energy to be supplied. Given this type of application, relatively thick membranes can be attached without a notable reduction of the acoustical energy reaching the respective heads 7, 8. A very small acoustical impedance is obtained if a thin membrane is used. Since the membranes 11, 12 are connected to the respective heads 7,8 via an adhesive in the exemplary embodiment, the membranes 11, 12 are brought into mechanical contact with the heads 7, 8, achieving a further reduction of the acoustical impedance. Since the membranes 11, 12 are replaceable, they are removed after an examination, and new membranes 11, 12 are applied prior to each new patient. As an alternative, the membranes 11, 12 can be autoclaved and reused.
FIG. 2 shows an ultrasonic flow meter 1, which differs from the ultrasonic flow meter 1 described in connection with FIG. 1 in that the inner diameter of the channel 4 is greater than the outer diameter of the respective transmit and receive heads 7, 8. Another difference is that the membranes 11, 12 are removably attached to the respective open ends 13, 14 of the channel 4. By pressing the respective heads 7, 8 of the transmitter 2 and the receiver 3 against the respective membranes 11, 12, almost all the air between the membranes 11, 12 and the heads 7, 8 is expelled, allowing the heads 7, 8 to be situated close against the membranes 11,12. In this exemplary embodiment, the membranes 11,12 need not be provided with an adhesive. In connection with the embodiment described in FIG. 2, the ultrasonic transmitter 2, the ultrasonic receiver 3 and the membranes 11, 12 can be removed after each examination, and new membranes can be applied to the respective heads 7, 8 prior to each patient. The transmitter and receiver are subsequently pressed against the respective membranes 11, 12 again, as described, and are locked in this position.
FIG. 3 depicts another schematically illustrated ultrasonic flow meter 15. In connection with this flow meter, the transmitter 17 and the receiver 18 are arranged on the same side of the elongated measurement chamber 18. The transmitter 16 can emit an acoustical signal, referenced 19, which is transmitted, via a number of reflections at the walls of the measurement chamber 18, through a gas mixture that flows through the measurement chamber 18, in order to subsequently strike the receiver, which accepts the transmitted acoustical signal. This general type of ultrasonic flow meter 15 is detailed in European Application 0 874 238. The diameter of those openings 20, 21 which are arranged at the measurement chamber and which are provided for the transmitter 16 and the receiver 17 is inventively approximately equally as large as the outer diameter of the respective heads 22, 23 of the transmitter 16 and the receiver 17. In this exemplary embodiment, a retainer 24 is arranged at the measurement chamber 18, containing a rolled stock of ribbon-shaped membrane 25. Prior to an examination, the ribbon-shaped membrane 25 is rolled far enough out of the retainer so that it covers the two openings 20, 21 of the measurement chamber 18. The membrane 25 can be provided with an adhesive at least on the side which comes to rest against the outer wall of the measurement chamber 26, in order to be able to apply the membrane rapidly and easily. The transmitter 16 and the receiver 17 are subsequently attached against the membrane 25 at the respective openings 21, 22. The membrane 25 can also be provided with an adhesive on the side directed opposite the measurement chamber 18. This is preferred and results in a very good contact between the heads 22, 23 and the membrane 25. The outer wall of the measurement chamber 18 is provided with a tear part 26 for the membrane 22. Subsequent to an examination, the transmitter 16 and the receiver are removed. The membrane 25 is detached from the outer wall of the measurement chamber 18. Subsequently, another length of membrane 25 is pulled out of the retainer 25 prior to the next examination, until the membrane 2 covers the openings 21, 22, the membrane 25 which was used in the preceding measurement being torn off with the aid of the tear part 26. The transmitter 16 and the receiver 17 are subsequently applied against the membrane 25 again.
FIG. 4 illustrates that the openings 20, 21 can be larger than the outer diameter of the respective head 22,23 of the transmitter 16 and of the receiver 17. In this exemplary embodiment, the transmitter 16 or the receiver 17 can be pressed against the membrane in order to reduce an air gap between said parts to a minimum, as described in connection with FIG. 2. In connection with this example, the part of the membrane 25 which faces the transmitter 26 or the receiver 17 need not necessarily be provided with an adhesive. The FIG. 4 depicts the opening 21 with the transmitter 16 only.
FIG. 5 illustrates that a sealing ring can be attached between the outer wall of the measurement chamber 18 and the membrane 28. In this type exemplary embodiment, it is advantageous for each opening 20, 21 of the measurement chamber 18 to be respectively provided with a membrane 28. The sealing ring 27 produces a good seal between the interior of the measurement chamber 18 3nd the atmosphere. FIG. 5 depicts the opening 21 with the transmitter 16 only. The opening 20 and the receiver 17 preferably have the same shape.
Although the present invention has been described with reference to a specific embodiment, those of skill in the art will recognize that changes may be made thereto without departing from the scope and spirit of the invention as set forth in the appended claims.
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A device for measuring a gas flow, has a measurement chamber and an ultrasonic transceiver unit which can be attached to the measurement (chamber over openings of the measurement chamber and which is provided with transmit and receive heads. The heads are directed against the openings of the measurement chamber, membranes being arranged between the measurement chamber and the transmit and receive heads which are permeable to ultrasound waves but largely impermeable to moisture and bacteria. In order to feed maximum acoustical energy to the ultrasonic transceiver unit while keeping moisture and bacteria away from the unit, the membranes are replaceably arranged close to the transmit and receive heads.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 655,561; filed Feb. 13, 1991, now U.S. Pat. No. 5,158,491.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to photolithographic deposition of CRT screens, including formation of black matrices and phosphor deposits. The present invention relates more specifically to photostencils used in near contact to the photosensitized faceplate to provide for interchangeable mask and screen type cathode ray tubes (CRTs).
2. Discussion of the Related Art
Those familiar with the art of phosphor screen application to the faceplate of a display device, such as the common color cathode ray tube, are aware of the advantages to be gained by utilizing near contact photoexposure techniques. Such advantages are set forth in the parent application, U.S. Ser. No. 07/655,561, filed Feb. 13, 1991, now U.S. Pat. No. 5,158,491. The parent application is herein incorporated by reference to avoid lengthy exposition of background unnecessary to the exposition of the present invention for those ordinarily skilled in the art.
Briefly, however, the near contact photoexposure screening technique, hereinafter called "near contact printing," utilizes a standardized photostencil placed very close to the photosensitive coating on the CRT faceplate to be exposed. The result is that each faceplate screened by near contact printing is alike in feature size and location to a high degree. This enables likewise standardized shadow masks to be fitted interchangeably in operable relation to the standardized screens.
As set forth in the parent application, an ideal photostencil, called the "parent stencil", for use in near contact printing is made, preferably by photoplotting. The pattern of photostencil features is dictated by the electron-optic characteristics of the operable CRT which govern the paths of the electron beams used to excite the phosphor deposits on the screen. This method of parent stencil generation is time consuming and expensive. The parent photostencil, or duplicates thereof, used in the screen exposure apparatus have a fixed photo-stencil pattern, the discrete elements, or light-passing apertures, of which will be referred to as the aforementioned "features."
Thus, the parent stencil is fixed in an idealized feature pattern but has only one feature size and shape. However, the requirements of the screen features in a given model of tube may change from time to time, due, perhaps, to changing tube specifications or to take advantage of other manufacturing efficiencies or cost saving. Thus, to introduce flexibility of feature size and/or shape to the CRT screen without generating a new parent stencil is highly desirable.
Since the parent stencil cannot be economically used in a factory environment, due to its high cost and susceptibility to damage, it is necessary to form progeny stencils, i.e., working copies therefrom. Because there is no need to duplicate electron beam optics with the near contact exposure apparatus, the parent stencil can be made in any manner necessary to create a working progeny stencil of proper pattern for exposure of the CRT screen. The present invention therefore, teaches the formation of a parent stencil proportional and featured so as to allow near contact print generation of the working progeny thereby enabling changes in the feature size and shape while retaining the feature pattern dictated by electron beam landings in the CRT. Control of the generation of progeny to maintain feature acuity is, of course, central to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Other attendant advantages will be more readily appreciated as the invention becomes better understood by reference to the following detailed description and compared in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures. It will be appreciated that the drawings may be exaggerated for explanatory purposes.
FIG. 1A illustrates formation of the parent stencil.
FIG. 1B is a side view of progeny stencil formation.
FIG. 2 and 3 illustrate known light sources for photoexposure of CRT screens.
FIG. 4 illustrates a light source according to the present invention.
FIG. 5 illustrates the principle of the present invention.
FIG. 6 illustrates a multiple exposure of a progeny stencil feature.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in FIG. 1A, the parent stencil 11, photoplotted, as per the parent invention, according to the dictates of the electron-optics of an operational CRT, has a fixed pattern of light-transmitting features 12. Unlike the embodiment claimed in the parent application, the parent stencil of the present invention is made to be smaller in feature size and pattern than the progeny stencil actually used in the light house. These features are of fixed size and shape, preferably, though not necessarily, round and of smaller size and pattern than the ultimately required working progeny stencil size necessary to expose finished screen. This is due to the intrinsic enlargement of light images originating in a point source passing through a photostencil and landing on an imaging plane spaced therefrom. Mathematical expression of such enlargement and the concomitant spacing of the exposure system elements is within the skill of the ordinary artisan. The features 12 in the parent stencil 11 are described as being round windows for creating a dot screen.
With reference now to FIG. 1B, a parent stencil 11 having light transmitting features 12 is depicted with progeny stencil blank 13 on one side thereof, and at a predetermined distance from, the parent stencil 11. The distance "d" may be in the range of 0.001" to 0.100" in order to maintain maximal image acuity. Consideration must be given to appropriate selection of the distance "d" in conjunction with the spacing required for the ultimate placement of the progeny stencils from the photosensitive faceplate of the CRT, as explained above. A nominal distance of 0.020" is recommended in order to keep the penumbra effects controlled while attaining the desired elongation of spot size. On the opposite side of the parent stencil 11, from the progeny stencil blank 13 is located an exposure light source 15. The progeny stencil blank 13 is coated with a photoresist 17, preferably, though, not necessarily, of the negative type. The photoresist 17 is exposed to the light 19 from the lamp 15, through a shader plate (not shown) to normalize light intensity and to form the progeny stencil pattern having different shape/sizes of features than the parent stencil 11 as further explained below.
A known type of exposure light source 15 for photodeposition of CRT screens is created by placing an opaque, apertured member 21 having a light transmitting aperture 22 over a standard screen exposure lamp 23. The lamp 23 may be a commercially available one kilowatt high-pressure mercury vapor lamp, such as lamp model #BHA704C supplied by ORC Manufacturing Company Limited of Tokyo, Japan. As seen in FIG. 2, the light source created for exposing a dot screen type image of the type shown in FIG. 1A is generally square. That is, the aperture has a length "L" equal to the apparent width "W" of the light source from the lamp 23 in order to approximate a point source of light. To expose a line type of image popular in the use of entertainment type televisions, one would ordinarily use a known line type light source as seen in FIG. 3. That is, the length "L" is many times the width "W" of the light source.
As seen in FIG. 4, the light source 15 according to the present invention, is made "over-square" or "rectangular" preferably by making the length "L" of the aperture 22 placed over the lamp 23 greater than the width "W". Use of this rectangular light source results in an oblong progeny feature 29 being exposed on photoresist 17 (FIG. 5). Use of a square light source merely recreates the same master feature shape on the progeny while use of a true line source may over-elongate the features of the progeny, resulting in merging of the features into one another. Thus, by changing the length "L" of the aperture 22 the light source 15 may be changed to produce different degrees of feature elongation on the progeny.
As seen in FIG. 6, the shape of the progeny feature 29 may be further varied by using multiple exposures and rotation of the lamp. The effect of the rotation of the lamp 23 is indicated in FIG. 6, in which a step sequential rotation of lamp 23 in 120° increments results in a series of multiple exposures on different axis to produce a six sided "clover leafed" feature configuration 31 on the progney stencil 13. The projected circumference of the feature in parent stencil 11, by which the clover leaf pattern 31 is produced, is indicated by the inner circle 33. It will be appreciated that a variety of configurations of progeny feature may be made by varying the aspect ratio of the light source 15 and the sequential rotations of the lamp 23.
It will also be recognized that the techniques described herein may be applied to the near contact printing of the screen itself. The screen will, in such case, be treated as a progeny of the working photostencil used in the production photoexposure apparatus. Such an alternative may, for example, be used to achieve "on the fly" production process flexibility of screen feature geometry.
Rather than rotating the lamp step--sequentially, it may be smoothly rotated through 360°, to provide a window that is circular and enlarged. A slightly longer exposure time is required for good acuity. Also, according to the present invention, the lamp 23 may be held stationary and the assembly comprising the parent stencil and the progeny stencil blank may be rotated as a unit about a common axis.
Exposure time depends on factors such as the distance between the lamp 23 and the parent stencil 11, the distance "d" between the parent stencil 11 and the progeny stencil 13, the sensitivity of the photoresist 17, and of the intensity of the source. By way of example, exposure times for progeny formation may be in the range of 2 to 60 seconds.
The benefits of the invention include:
1. a single parent stencil can be the basis for many different feature sizes or shapes, or both, in progeny stencils;
2. the positions of the feature in a progeny stencil will correspond in precise proportionality with the positions of the features in the parent stencil, as required by the electron-optics of the operational CRT;
3. a change in the shape of the features in a progeny stencil does not require a substantial increase in exposure times, but only a lamp with a slightly longer aperture;
4. in a dot screen system, if the features must be made oblong, they can be made so on any axis.
The method according to the present invention can also be used to form progeny stencils having different slot or slit features than a parent stencil for use in forming line screens.
While particular embodiments of the invention have been shown and described, it will be readily apparent to those skilled in the art that changes and modifications may be made in the present invention without departing from the spirit thereof, and therefor, the purpose of the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.
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A method is disclosed for manufacturing photostencils used in screening the faceplates of color cathode ray tubes. The photostencils are produced as progeny from a parent stencil photo plotted according to the dictates of a proximity photoprinting process in conjunction with the electron optical characteristics of the operational CRT. A rectangular beam is used for radiating light through the pattern of features on the parent stencil onto the photoresist of the progeny stencil. As a result, the features of the progeny stencil differ in size or shape or both, from those of the parent stencil.
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This is a division of application Ser. No. 07/427,346 filed Oct. 27, 1989, now U.S. Pat. No. 5,045,208.
BACKGROUND OF THE INVENTION
This invention relates to column chromatography and, more particularly, to an improved column analyzer system which provides for automatic column chromatography and automatic optical density processing.
Column chromatography (often called microchromatography) is a well-known technique utilized as part of clinical chemistry for analyzing the various constituents of fluids such as blood. For example, Helena Laboratories Corporation, the assignee of the present invention, has marketed equipment and accessories for column chromatography as well as photometers or optical readers. Patent literature relating to column chromatography includes, for example, U.S. Pat. No. 4,341,635 issued Jul. 27, 1982 to Tipton Golias and assigned to Helena Laboratories Corporation (as well as the prior art cited therein), and there is commercially available equipment relative to automating one or more aspects of column chromatography. For example, at least one machine has been marketed prior to the present invention which automates the introduction of fluids into a chromatograph column, and the collection of the eluates from the column. Such equipment also provides for the processing of a plurality of chromatograph columns which are arranged in an array or matrix within the equipment.
The prior art, however, suffers from numerous disadvantages and shortcomings relative to the safe, accurate and expeditious chromatographic processing and subsequent optical density readings.
For example, according to the prior art, the eluate solutions are collected in a series of cuvettes, one cuvette for each eluate solution or fraction. Thereafter, the cuvettes are sequentially processed in an optical reader. This technique is time consuming, permits errors in identification of the cuvettes and exposes the technician handling the cuvettes to biological hazards such as HIV virus which may be carried in the blood specimens. The equipment which automates the processing of columns has heretofore discharged the eluates into a series of test tubes, and then the technician or operator of the equipment must manually transfer the contents into a series of cuvettes since test tubes, because of their curvature, are not amenable to optical density reading.
While extremely high pressure liquid chromatography (HPLC) is well known, and while pressurized chromatography is known based upon the aforementioned Golias U.S. Pat. No. 4,341,635, we have discovered that a constant low pressure greatly enhances liquid chromatography. Prior to the present invention, however, constant low pressure liquid chromatography was not available.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcomings of the prior art by providing a new and improved column analyzer system and method.
The column analyzer system of the present invention provides for the automated processing of an array of chromatographic columns, including removal of caps from the columns, without technician intervention and which provides for the follow-up optical density reading of the eluted solutions.
The present invention provides for an automatic removal of the protective cap at the bottom of the chromatograph column and provides for elution of liquid fractions into a new and improved cuvette such that a single cuvette will contain, in separate cells, the eluates and the total fraction.
The present invention further provides for constant, low pressure on each column during the chromatographic process through the use of a new and improved pressure system.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects and advantages of the present invention, together with other advantages which may be obtained by its use, will become more apparent reading the following detailed description of the invention taken in conjunction with the drawings.
In the drawings, wherein like reference numerals identify corresponding components:
FIG. 1 is an illustration of a chromatograph column according to the principles of the present invention;
FIG. 2 is a perspective illustration, partially broken away, of the cuvette of the present invention;
FIG. 3 illustrates, in perspective view, a rack for supporting a plurality of chromatograph columns according to the principles of the present invention;
FIG. 4 illustrates in section the apparatus for removing the caps from the chromatograph columns;
FIG. 5, comprising FIGS. 5A, 5B and 5C, illustrates the cap removal means with elevation views of each end thereof and with an edge view thereof;
FIGS. 6 and 7 illustrate the system for supplying constant, low pressure including a pressure regulator;
FIG. 8 illustrates the pressure tip associated with a single chromatograph column in a first position disengaged from a column;
FIG. 9 illustrates a pressure tip associated with a single column in the engaged position;
FIG. 10 illustrates, in perspective view, the apparatus of the present invention;
FIG. 11 illustrates, in perspective view, a tray for supporting the cuvettes of the present invention;
FIG. 12 illustrates a portion of the top of the column rack and a portion of the manifold in a disengaged position as seen from the back of the apparatus;
FIG. 13 illustrates the top of the column rack and portion of the manifold of FIG. 12 in an engaged position;
FIG. 14 is a partial front illustration with the door of the apparatus removed;
FIG. 15 is a diagrammatic illustration of the motor and linkage for positioning the manifold in the disengaged apart position;
FIG. 16 is a diagrammatic illustration of the motor and linkage for positioning the manifold in the engaged position; and
FIG. 17 illustrates, diagrammatically, the apparatus of the present invention including, in general terms, the frame or chassis, the location of various fluid supplies and the location of the optical density reader.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings, FIG. 1 illustrates a conventional chromatograph column 10 which includes a upper end or cover 12 threadingly engaged onto the body portion of the column. The body portion of the column includes a downwardly and inwardly tapering reservoir portion 14 communicating with a barrel portion 16 which barrel portion contains ion exchange resin particles. The lower end of the barrel portion 16 tapers downwardly to a tip portion 18 which is covered by a removable cap 20. The column 10 as described and illustrated, including a threadable cover 12 (threads 13 are shown in FIG. 4), is conventional.
During liquid chromatography, it has been conventional, prior to the present invention, for the eluates to be discharged into a series of cuvettes or a series of test tubes. When test tubes are used, the contents are subsequently transferred into cuvettes since the curvature of the body of a test tube interferes with the optical density reading. A cuvette, with its generally flat walls, avoids the problem of distortion of the optical density. However, prior to the present invention, each of the eluates from a chromatographic process have been collected in discrete cuvettes leading to the risk of errors in the processing of the individual cuvettes.
The present invention provides an improved cuvette mean 24 which provides for the collection of all of the eluates from a single column within separate cells of a single cuvette means. With reference to FIG. 2, the cuvette means 24 is a generally rectangular container having opposed, parallel, spaced-apart side walls 26, 28, and opposed, spaced-apart parallel end walls 30, 32 oriented perpendicular to the side walls. The side walls and end walls of the cuvette means are mounted on a base 34, and the side walls and end walls, together with the base, define a rectangular container which is open at the top and closed at the bottom.
By way of example, but not by way of limitation, the cuvette means may include four separate cells. Three interior walls 36a,b,c extend between the side walls 26, 28, with the interior walls being generally parallel to the end walls 30, 32. The cuvette means thus defines four discrete cells 38a,b,c,d, respectively. Each cell is defined by the base 34, the side walls 26, 28, and two additional walls. In the case of cell 38a, the two additional walls are walls 30 and 36a; for cell 38b, the two additional walls are walls 36a and 36b. The two additional walls which define cell 38c are interior walls 36b and 36c. The two additional walls which define cell 38d are walls 36c and 32. It should be noted that cells 38a,b,c are of generally equal size and are substantially smaller than cell 38d for reasons which will be hereinafter explained.
Referring to FIGS. 3, a rack 42 is provided for supporting an array of columns. The rack includes upper and lower plates 44, 46, respectively, supported and maintained in spaced-apart relationship by a plurality of cylindrical rods 48. In the present embodiment of the invention, the upper and lower plates support 50 columns in a 5×10 array. The upper plate 44 is provided with a series of circular apertures 50 of a size and shape to receive the barrel 16 of the column 10. Adjacent each circular aperture is a rectangular aperture 52 to accommodate the automatic column cap removal means which will hereafter be explained. The lower plate 46 includes a plurality of apertures 54 which are generally rectangular in configuration. Each generally rectangular aperture 54 includes opposed short walls, a first longer wall 56 interconnecting the short walls, and a second wall 58 opposed from the longitudinal wall 56 which second wall includes a generally circular cutout portion. The diameter of the generally circular cutout portion is configured to support the lower end of the barrel 16 of the column, and is aligned under the circular aperture 50 in the upper plate, and the longitudinal wall 56 is a bearing surface for the automatic cap removal. In FIG. 3, only a single set of apertures in plate 44 is illustrated although 50 such sets, in a 5×10 array are contemplated. Similarly, only a single aperture 54 is illustrated in plate 46 although a 5×10 array is contemplated. The rack is positioned at a first station in the apparatus of the present invention.
After the chromatography columns are loaded into the rack and placed in position at the first station in the apparatus of the present invention, means are provided for automatically removing the cap 20 from the lower end of each column. FIG. 4 illustrates two positions of the cap removal means, a rest position illustrated by dashed lines and an active position illustrated by solid lines. Specifically, the automatic cap removal means 60 is an elongated, thin, stainless steel spring strip extending generally vertically through the rectangular portions of the apertures 52, 54 in the upper and lower plates of the rack 42. As also illustrated in FIG. 5, the elongated, thin, steel spring includes a fork portion 64 at the lower end, an apertured upper end 66 for attachment to an actuating mechanism and a series of intermediate portions 68 therebetween, one of which intermediate portions 70 bears against the bearing surface wall 56 as the cap removal means is moved vertically downward within the rack 42. Of course, one cap removal means is provided for each column within the array. Actuating mechanism 139 is attached to the spring by screws extending through the apertures in spring end 66. As the actuating mechanism moves the spring 60 vertically downward, section 70 bears against the longitudinal wall 56 in the lower plate 46. The continued downward movement of the spring against the bearing surface 56 urges the fork means to the left as illustrated in FIG. 4 to engage the tip 18 of the column between the fork tines. The continued downward movement of the spring continues the biasing of the fork 64 against the tip such that the underside of the fork engages the top of the cap 20 and forces the cap downwardly until the cap is free of the column. The cap will, in practice, be retained in the first cell 38a of the cuvette means. Thereafter, the cap removal means is withdrawn vertically upwardly.
Means are provided for automating the column chromatography processing including such steps as applying hemolysate to the sample, agitating the column, running a buffer through the column, thereafter adding the sample to the column, adding the reagent to the column, etc. In general terms, this automatic technique is part of the prior art. However, the present invention includes certain features which are not found in the prior art, namely, the provision of constant, low pressure for the chromatography columns which are being processed. The pressure system will now be explained.
Referring to FIGS. 6 and 7, the pressure system includes a compressor 80 for providing constant air pressure to an input port 81 of a regulator 82. The regulator 82 also includes an output port 83.
The regulator 82 includes two pressure relief bores 84, each of which is generally T-shaped in cross section and each of which communicates with a main conduit 86 such that air from the compressor 80 flows through the input port 81, through the main conduit 86 and through the output port 83 of the regulator. The two relief bores 84 are provided to permit operation of the regulator at two different constant pressures. For this purpose, each relief bore is provided with a projectile shape plunger 88, the plunger in one relief bore being of a different weight than the plunger in the other relief bore. In addition, each relief bore 84 may be selectively closed at the exterior surface thereof such that only one relief bore will be in use at any given time. FIG. 7 illustrates the orientation of the regulator 82 when in use. It will be noted that relief bores 84 are positioned at an angle relative to the vertical axis. In operation, with the plungers mounted within the respective relief bores and with one of the relief bores open and the other closed, if the air pressure through the conduit exceeds a threshold as determined by the weight of the plunger associated with the open relief bore, the air will move the respective plunger upwardly, thus opening a fluid flow path through the relief bore thus providing for a bleed of air pressure. When sufficient air pressure bleeds out through the relief bore, the plunger drops back to seal the relief bore from the main conduit. Positioning the plungers in bores 84 at a angle to the vertical facilitates movement of the plungers.
According to the principles of the present invention, a low but constant air pressure should be maintained at the output port 83, Which low pressure should range from about 3 inches of water to about 8 inches of water, depending upon the particular column chromatographic test. Thus, within that range, the weights of the two plungers may be selected such that one plunger is sufficiently light so as to permit a constant air pressure equivalent to three inches of water, and the second plunger is slightly heavier, thus permitting a constant air flow pressure at eight inches of water. It should be further appreciated that it is within the spirit and scope of the present invention to modify the air pressure while still providing constant, low pressure and thus the range of three--eight inches of water as the measurement of the air pressure is illustrative. Slightly less than three inches and slightly more than eight inches may be utilized while achieving the objectives of the present invention.
Referring next to FIG. 8, it should be remembered that the columns are provided in an array, heretofore described as a 5×10 array, namely, 10 chromatograph columns in each of 5 rows. The output from the pressure regulator 82 is coupled through tubes 93 to each of five manifolds 94, each associated with one row. Each manifold 94 is connected to a pressure tip system of the present invention for providing the desired pressure to each of the chromatograph columns while, at the same time, preventing leakage of air if less than a full array of columns is being processed by the system. The pressure tip system, as illustrated in FIG. 8 in the absence of a chromatograph column, includes an upper block or manifold 94 having a conduit 96 therethrough in fluid communication through tube 93 with the output 83 of the pressure regulator. Mounted partially within the block 94 is an elongated pressure cylinder 98, of generally circular cross section, having three reduced diameter circumferential recesses machined therein. Specifically, cylinder 98 has an upper grove or recess 100 machined therein, the upper groove positioned inwardly of a flange 102. An O-ring seal 104 is positioned within the groove 100. A second groove 106 is provided intermediate the two ends of the cylinder 98, and an O-ring 108 is positioned in the second groove 106. A third groove 110 is provided in the cylinder adjacent the second end and is spaced inwardly therefrom such that a lower flange 112 is provided at the second end of the cylinder 98, and a flexible, foam gasket 114 is provided and mounted in the groove 110, the foam gasket 114 being retained by the flange 112. The cylinder 114 has a longitudinal bore 116 extending through the flange 112 and through the body of the cylinder, the bore 116 extending along the longitudinal center line of the cylinder and terminating just inwardly of the upper groove 100. A transverse bore 118 is provided generally perpendicular to the longitudinal bore 116 and intersecting the longitudinal bore 116 at the end thereof inwardly of the upper groove 100. The longitudinal bore 118 is in fluid communication with a circular passageway 120 which is provided within the block 94.
In the absence of a chromatograph column, the pressure tip system is positioned as illustrated in FIG. 8 such that the weight of the pressure tip system pulls the cylinder vertically downwardly causing the O-ring 104 to seal the top of the passageway 120 from the conduit 96, thus preventing the air flow from entering the vertical passageway 120. Thus, O-ring 104 functions both as a seal and also as a retainer which engages the flange 102 and prevents the cylinder mechanism 98 from dropping downwardly out of the passageway 120 of the block 94.
During the operation of the system of the present invention, the entire pressure system is movable such that cuvettes may be placed in the chassis, and chromatograph columns may be placed in frame 42 within the chassis. Thereafter, the pressure system is moved into position relative to the chromatograph columns and lowered into position such that for each chromatograph column mounted in the rack 42, the reservoir top 14 of the column 10 engages the underside of the foam gasket 114 and pushes upward on the foam gasket such that the foam gasket, while still mounted in the groove 110, moves the cylinder 98 upwardly until the O-ring 108 seals the vertical passageway 120 at the bottom of the block 94. This is illustrated in FIG. 9. Simultaneously pressure between the top of the column 10 and the underside of the foam gasket 114 provides an air-tight seal at the top of the column. Lastly, the vertical upward movement of the cylinder 98 moves the upper O-ring 104 clear of the top of the passageway 120. Thus, air pressure through the conduit 96, which is in communication with the output port 83 of the pressure regulator flows through the conduit 96 (for each pressure tip unit), downwardly through the passageway 120 and through the horizontal bore 118 and the vertical bore 116 and thereafter into the top of the chromatography column. A pressure system such as illustrated in FIGS. 8 and 9 is associated with each location in the array of columns.
Thus, it may be appreciated that if a full array of columns is being processed, each column presses upwardly on its respective foam gasket 114 to permit air pressure to flow into the top of the chromatograph column whereas in each position within the array, which is characterized by the absence of a chromatograph column, the pressure system remains in the position of FIG. 8, and no air enters the cylinder 98 associated therewith.
Referring next to FIG. 10, a perspective illustration of the apparatus of the present invention is illustrated. The apparatus of the present invention includes a chassis or frame 130. The frame or rack 42 for the chromatographic columns is mounted within a housing 132 attached to the frame. FIG. 10 also illustrates the five manifolds 94 positioned above the rack 42, the five manifolds or blocks extending from the front to the rear of the housing 132. The cuvettes are positioned below the housing 132 as will be described hereinafter.
Above the housing, a horizontal support block 134 is mounted for movement laterally, i.e., in the "X" direction. Thus, the block 134 moves left and right. Mounted within the block are four discharge needles 136, 137, 138, 139 (see FIG. 17). The needles move as a group in the "Y" direction, i.e., forwardly and rearwardly of the block 134. The needles also move in "Z" or vertical direction. A tray 142 for supporting the cuvettes is slidably mounted under the housing 132 (see FIG. 11).
FIG. 11 illustrates, in perspective, the tray 142 for the cuvettes, the tray including a generally flat surface or floor 144 upon which the cuvettes are placed, the floor being provided with guide rails 146 on three sides thereof. A handle 148 is provided on the tray for movement of the tray of cuvettes into and out of the apparatus of the present invention. The tray of cuvettes has been removed from FIG. 10 for the purposes of clarity and ease of illustration.
FIG. 12 illustrates, in perspective form, a rear view portion of the apparatus of the present invention including the movement of the pressure tip system of engagement with the chromatograph columns. In FIG. 12, three of the manifolds or blocks 94 are visible as is the upper plate 44 of the tray 42 with two chromatograph columns 10 in place, one in each of two rows. At the upper right-hand corner of FIG. 12, a vertical link 150 is illustrated. When the system is in the position illustrated in FIG. 12, the needles 136, 137, 138 can access the tops of each of the chromatograph columns such that fluids may be introduced therein.
Referring next to FIG. 13, which is a perspective illustration similar to FIG. 12 except that link 150 is now vertical, there has been movement of the manifold blocks such that the manifold blocks 94 are now above the columns and the pressure tip system of FIGS. 8 and 9 is now in contact with the tops of the columns.
FIG. 14 illustrates an enlarged, partial front elevation view of the apparatus of the present invention with the door 152 of FIG. 10 open. In this position, a first group of mixing needles 154 is illustrated. There are four such needles, one to be associated with each cell of a single cuvette. After chromatographic separation, the cuvette is moved to the right in FIG. 14 by a stepping motor and is held in position underneath the needles 154 such that the fluid within each cell may be thoroughly mixed. The cuvette is then moved further to the right in FIG. 14 to be scanned by an optical reader 156 (see FIG. 17). After scanning by the optical reader 156, the cuvette advances further to the right under a second group of needles 158 which contain fluid for washing out the cuvette cells.
It was previously indicated that cuvette cell 38d is larger than the other three cuvette cells. This is because in column chromatography, it is common to collect eluates and, in a separate container, dilute a second sample (e.g., of blood or other biological fluid) such that comparative optical density readings may be taken for providing an indication if all of the sample has moved through the chromatograph column. This technique is, of course, well known.
FIG. 15 illustrates, in diagrammatic form, linkage and a motor 160 for moving the manifold system in the retracted position, relative to the tops of the individual chromatograph columns such that reagents, samples and the like may be introduced therein.
FIG. 16 illustrates, diagrammatically, the linkage and motor system of FIG. 15 in the engaged position, illustrating the 90° rotation of the aforementioned link 150. It should be noted that while FIGS. 12 and 13 provide a rear perspective illustration, FIGS. 15 and 16 provide a front elevation diagrammatic illustration.
Referring next to FIG. 17, an overall system illustration of the present invention will now be described. Block 134 is illustrated as mounted to a stepping motor system 162 which moves the block 134 laterally through a drive belt 164. The cuvettes are processed from right to left and from front to back as illustrated in FIG. 17. To accomplish this, a bar or fence 166 extends across the width of the housing 132, underneath the housing but above the tray 142, and one end of the bar is connected to a drive mechanism 168. Advancing the drive mechanism 168 moves the bar 166 forwardly such that five cuvettes 24, one from each row, moves forwardly clear of the tray 142 and onto a drive mechanism 170. Drive mechanism 170 includes a pusher block 172 which advances the cuvettes sequentially underneath the mixer needles 154, through the optical reader 156, and thereafter underneath the evacuator needles 158 which are connected through a pump to a waste evacuation system. After the five cuvettes are processed, drive system 168 advances the bar 166 forward, yet another step, such that the next row of five cuvettes may be deposited onto the drive belt 170 and processed sequentially. FIG. 17 also illustrates a cuvette 24a dropping off the drive mechanism after the completion of mixing, reading and evacuation.
It should be further appreciated that as part of the present invention, a cam 176 is provided, illustrated diagrammatically in FIG. 17, which is mounted on a motor such that at the completion of the chromatographic separation, rotation of the motor causes raising and lowering the entire housing 132. This movement causes any drops at the bottom of the tips of the chromatograph columns to drop into the respective cells of the cuvettes.
The three needles 136, 137 and 138, illustrated in FIG. 10 and in FIG. 17, each move in the "Z" direction under influence of motors and thus provide for mixing or agitation of the resin in the column as well as providing conduits for the addition of reagents and/or samples into the columns. In addition, vertical movement of decapper needle 139 provides for removal of the tips from the columns. Thus, needle 139 functions to move spring 62 downwardly.
Reference should also be had to the bellows-motor 180 illustrated in FIG. 17 wherein four bellow systems are illustrated, each associated with one of the needles 154 and each attached to a motor 182. Motor 182 rotates, and an internal threaded nut system converts the rotation motion of the motor 182 into linear motion of the bellows 180 which, in turn, moves the needles 154 vertically for mixing the liquid in the cuvette cells prior to the liquid passing through the optical reader 156.
The bellows-motor arrangement illustrated with respect to the needles or mixer unit 154 may be replicated for movement of the needles 136-140 as they provide controlled, bi-directional movement in small increments.
The foregoing is a complete description of a preferred embodiment of the present invention. The invention automates those steps normally performed by a technician in a manual pipetting operation, and the individual steps, per se, are conventional.
Many changes and modifications may be made without departing from the spirit and scope of the present invention. The invention, therefore, should be limited only by the following claims.
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An analyzer system for automatic column chromatography, and method for its use, includes an array of chromatograph columns and multi-cell cuvettes associated with each column. Chromatographic separation takes place under a constant, low fluid pressure. A pressure system distributes air to each column during chromatographic separation but prevents leakage of air if the column array is partially empty. The multi-cell cuvette collects and separates the eluates associated with a single column. The system provides for automatic removal of caps from the bottoms of the chromatograph columns and provides for automatic optical density reading.
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FIELD OF THE INVENTION
This invention relates to the field of data communications. More particularly, the invention relates to cable drivers, line drivers, wave shaping of digital pulses and rise and fall control circuits.
BACKGROUND OF THE INVENTION
The transmission of digital data along a transmission line may be accomplished using a cable driver. The cable driver receives the signal to be transmitted and generates a corresponding signal on the transmission line. One objective in the design of cable drivers is to maximize the rate at which data may be transmitted (the “data rate”) on the transmission line. Among other limitations, the maximum data rate which may be transmitted will be limited by two considerations:
i. The cable driver should not generate excessive electromagnetic radiation, which may affect the operation of other devices near the cable driver. To avoid electromagnetic radiation, the 20% to 80% rise and fall time of the low to high and high to low transitions of the output signal of the cable driver must not be less than a specified minimum rise/fall time. In the case of some cable drivers used in the motion picture and television industries, the Society of Motion Picture and Television Engineering (SMPTE) has set out a minimum rise/fall time of 400 pico-seconds (See SMPTE Standard 259M: 10-Bit 4:2:2 Component and f SC Composite Digital Signal Serial Digital Interface).
ii. The cable driver should minimize any jitter in its output signal by ensuring that the output signal is within a specified tolerance of its steady state level prior to the start of the next transition of the output signal.
Prior art cable drivers control the rise and fall times of the output signal with a resistor-capacitor circuit. Such circuits exhibit exponential low to high and high to low output transitions with the result that the output signal takes a relatively long time to settle within the specified tolerance to minimize jitter, while still having a sufficiently long 20% to 80% rise and fall time. Consequently, the data rate which can be transmitted by prior art cable drivers is limited.
BRIEF SUMMARY OF THE PRESENT INVENTION
The maximum data rate which can be transmitted may be increased by designing the cable driver to have linear low to high and high to low output transitions.
Accordingly, it is an objective of the present invention to provide an improved cable driver which has substantially linear low to high and high to low output transitions.
The primary feature of the improved cable driver is the ability to transmit data at higher data rates without increased jitter or electromagnetic radiation. In addition, the improved cable driver reduces the problems of ringing and overshoot in the output signal.
In one aspect, the improved cable driver comprises (a) an input port for receiving an input signal, comprising first and second input terminals; (b) an output port for transmitting an output signal on a transmission line, comprising first and second output terminals; (c) a first resistance and a second resistance for defining an output signal at said output port, said first resistance being coupled between a voltage source and said first output terminal and said second resistance being coupled between said voltage source and said second output terminal; (d) a plurality of switching stages, wherein each of said switching stages comprises a switch and a current source associated with said switch for producing a current, said current source being coupled to its associated switch and each of said switches being coupled to said output port; (e) a plurality of delay stages for providing a delay time, (f) one of said switching stages being coupled to said input port and the remaining switching stages being coupled in series, with a delay stage between at least some of successive pairs of said switching stages so that the rise and fall times of a selected portion of said output signal exceeds a selected duration.
In a second aspect, the improved cable driver comprises (a) an input port for receiving an input signal, comprising first and second input terminals; (b) an output port for transmitting an output signal on a transmission line, comprising first and second output terminals; (c) a first resistor and a second resistor for defining an output signal at said output terminal, said first resistor being coupled between a first voltage source and said first output terminal, and said second resistor being coupled between the first voltage source and said second output terminal, wherein the resistances of said first resistor and said second resistor are equal to the impedance of the transmission line; (d) a plurality of switching stages, wherein each of said switching stages comprises a switch and a current source associated with said switch for producing a current, said current source being coupled between its associated switch and a second voltage source, and each of said switches being coupled to said input port and being responsive to said input signal for coupling its associated current source to said first output terminal or said second output terminal and being capable of switching between said first output terminal and second output terminal with a specified switching time and wherein the switching time of each of said switches is equal; (e) a plurality of delay stages, such that the number of delay stages is one less than the number of switching stages, for providing a delay time, wherein each of said delay stages is coupled between a pair of said switches of said switching stages, for delaying the response of said switches to said input signal such that said switches operate in a sequential order and wherein the delay time of each of said delay stages is equal, and the delay time of said delay stages and the switching time of said switches are selected such that the output signal is substantially linear.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a prior art cable driver.
FIGS. 2A & 2B show the input and output signals of the prior art cable driver.
FIGS. 3A & 3B show the jitter introduced into the output signal when the prior art cable driver receives a short input pulse.
FIG. 4 shows a low to high transition of the output signal of the prior art cable driver.
FIG. 5 shows the improved cable driver in block diagram form.
FIGS. 6A & 6B and 7 A & 7 B show the transition of switches which comprise the improved cable driver the output signal of the improved cable driver.
FIG. 8 shows the switching stage and delay stage of the improved cable driver.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is first made to FIG. 1, which shows a prior art cable driver 20 for transmitting a digital signal over a transmission line. The prior art cable driver 20 comprises an input port 22 , a switch 24 , a current source 26 , resistors 28 and 30 , capacitors 32 and 34 , output stages 36 and 38 and an output port 44 .
Capacitor 32 and resistor 28 are connected in parallel between V CC and node 42 . Capacitor 34 and resistor 30 are connected in parallel between V CC and node 40 . Current source 26 is coupled between switch 24 and ground. Switch 24 is responsive to an input received at input port 22 and may couple current source 26 to node 42 through node H or to node 40 through node L. Output port 44 comprises output terminals 46 and 48 .
Output stage 36 comprises transistor Q 1 , and resistors 50 and 52 . Transistor Q 1 is connected as an emitter follower stage. The base of transistor Q 1 is connected to node 42 . The emitter of transistor Q 1 is coupled to ground through resistor 52 and to output terminal 46 through resistor 50 . The collector of transistor Q 1 is coupled to V CC . Output stage 38 is similarly comprised of a transistor Q 2 and two resistors 54 and 56 . The base of transistor Q 2 is connected to node 40 . The emitter of transistor Q 2 is coupled to ground through resistor 56 and to output terminal 48 through resistor 54 . The collector of transistor Q 2 is connected to V CC .
In use, the prior art cable driver 20 will be configured to produce a differential output signal V out at output terminals 46 and 48 . The differential output signal is defined as the difference between the voltage at output terminal 48 (V 48 ) and the voltage at output terminal 46 (V 46 ):
V out =V 48 −V 46 .
The differential output signal V out will be positive when V 48 is higher than V 46 and this condition will be referred to as a high output signal. Conversely, the differential output signal V out will be negative when V 48 is lower than V 46 and this condition will be referred to as a low output signal. Although the description here is given with respect to a differential output signal, one skilled in the art will recognize that the individual components of the output signal V out at terminals 46 and 48 may be used independently, for example, to drive a single ended cable.
The prior art cable driver 20 operates as follows. A differential input signal, V in , is received at input port 22 , which comprises input terminals 58 and 60 , and is directed to switch 24 . The differential input signal consists of two voltage signals, one of which is received at terminal 58 and the other of which is received at terminal 60 . V in is defined as the voltage at terminal 60 (V 60 ) minus the voltage at terminal 58 (V 58 ):
V in =V 60 −V 58 .
V in will be positive when V 60 is higher than V 58 (defined as V in =V IH ). This condition will be referred to as a high input signal. Conversely V in will be negative when V 60 is lower than V 58 (defined as V in =V IL ) and this condition will be referred to as a low input signal.
Switch 24 is responsive to the differential input signal V in and switches between nodes L and H depending on whether differential input signal V in is low or high, respectively. When differential input signal V in is high, switch 24 will connect current source 26 to node H and conversely, when differential input signal V in is low, switch 24 will connect current source 26 to node L.
Assuming that differential input signal V in is initially low, switch 24 will couple current source 26 , which has a current I 26 , to node 40 . Current I 26 will flow through resistor 30 , which has a resistance R 30 , and capacitor 34 . Capacitor 34 will be charged and the voltage at node 40 will fall to V CC −V 34 , where V 34 is the voltage across capacitor 34 . Capacitor 34 will charge until the voltage at node 40 falls to V CC −I 26 R 30 . The voltage at output terminal 48 will be V CC −I 26 R 30 −V BE2 , where V BE2 is the base-emitter voltage of transistor Q 2 .
Simultaneously, any charge on capacitor 32 will be discharged through resistor 28 , which has a resistance R 28 . When capacitor 32 is fully discharged, the voltage at node 42 will be V CC and the voltage at output terminal 46 will be V CC −V BE1 , where V BE1 is the base emitter voltage of transistor Q 1 . Assuming that the base-emitter voltages of transistors Q 1 and Q 2 are the same and are equal to V BE (i.e. V BE1 =V BE2 =V BE ), the low value of the differential output signal V out will be V OL = V 48 - V 46 = ( V CC - I 26 R 30 - V BE ) - ( V CC - V BE ) = - I 26 R 30
When the differential input switches from low to high, switch 24 will couple current source 26 to node 42 . Current I 26 will now flow through resistor 28 and capacitor 32 , which was previously discharged. Capacitor 32 will charge and the voltage at output terminal 46 will fall to V CC −I 26 R 28 −V BE . Simultaneously, capacitor 34 , which was previously charged will discharge through resistor 30 and the voltage at output terminal 48 will rise to V CC −V BE . The high value of the differential output signal V out will thus be V OH = V 48 - V 46 = ( V CC - V BE ) - ( V CC - I 26 R 28 - V BE ) = I 26 R 28
When the differential input switches from high to low, the process described above will occur in reverse and the differential output signal will return to its initial value of −I 26 R 30 .
The specific output voltage levels will depend on the magnitude of current of current I 26 and the resistances R 28 and R 30 . If both resistors have the same value (as they generally will), the differential output voltage swing will be 2I 26 R, where R is the resistance of resistors 28 and 30 .
One skilled in the art will understand that emitter follower output stages 36 and 38 are required to match the output impedance of the transmission line to which the cable driver's output is directed. The impedance of a transmission line is generally resistive with very low reactance. The resistance of resistors 50 and 54 will normally be equal to the resistance of the transmission line. The use of the emitter follower output stages 36 and 38 introduces a potential problem of ringing and overshoot in the differential output signal appearing at output port 44 . The cable driver 20 will normally be integrated onto a single chip with a package. Emitter follower stages are typically inductive and combined with the parasitic capacitance of the cable driver's package, the output stage 36 or 38 may introduce resonance into the output. If this resonance is substantial, the overshoot and ringing introduced into the transmission line may exceed acceptable tolerances, depending on the particular installation of the prior art cable driver 20 .
Reference is now made to FIGS. 2A and 2B, which shows the input and output voltages of the prior art cable driver 20 , respectively. FIG. 2A shows differential input signal V in received at input port 22 and FIG. 2B shows the differential output signal V out generated by the prior art cable driver 20 at output port 32 in response to the differential input signal V in .
As shown, the differential output signal V out rises and falls exponentially due to the presence of capacitors 32 and 34 in the prior art cable driver 20 . One skilled in the art will recognize that these capacitors in fact increase the rise and fall times of the differential output signal V out . However, these capacitors are required to ensure that the 20% to 80% rise and fall times are not less than the specified minimum time, and therefore ensure that electromagnetic radiation is not produced in the prior art cable device driver. The exponential rise and fall curve of the differential output signal limits the maximum bandwidth of the prior art cable driver 20 , as will be explained below.
As shown at point A on FIGS. 2A and 2B, when the differential input signal V in does not remain high for a sufficiently long period, the differential output signal V out does not approach its maximum output level. When the differential input signal V in subsequently steps from high to low, the differential output signal begins to fall. The starting voltage level for the high to low transition of the output signal is lower than in the normal case, introducing pattern jitter into the differential output signal V out . The same effect is seen at point B when the differential input signal V in has a short low input pulse.
Reference is next made to FIGS. 3A and 3B which show the effect of this pattern jitter more clearly, in the case of a short low input pulse. The dashed line in FIG. 3A shows a normal low input pulse in the differential input signal V in . The dashed line in FIG. 3B shows the corresponding differential output signal V out . Sufficient time has elapsed by the end of the normal low input pulse to permit the differential output signal V out to reach its normal low level V OL . The solid line in FIG. 3B shows the differential output signal V out when the differential input signal V in has a short low input pulse, shown by the solid line in FIG. 3A, and the low to high transition occurs before the differential output signal V out reaches V OL . In FIG. 3B, the difference between the dashed and solid lines is time jitter, as shown.
The degree of jitter may be calculated as follows. If the time at which the low pulse of the differential input signal V in ends is time 0 , then the voltage of the output differential signal V out , in the normal case (dashed lines), may be written V out = V OH - ( V OH - V OL ) e - t R 28 C 32 ,
where C 32 is the capacitance of capacitor 32 and t is time in seconds. To simplify the calculation of jitter, we make the following exemplary definitions:
V OH =1 volt
V OL =0 volts
R 28 =R
C 32 =C
Once skilled in the art will be capable of selecting appropriate components for the prior art cable driver 20 to produce these V OH and V OL voltages.
Thus, V out may be written V out = 1 - e - t RC .
The time at which V out reaches any particular voltage Va may be written
t=−RC ln (1 −Va )
Thus, the time t o at which V out reaches a voltage of 0.5V is
t o =−RC ln (0.5)
If the low to high transition of the input differential signal occurs when the differential output signal has a value of 0.02V (within 2% of its steady state value of 0V), V out may be written V out = 1 - 0.98 e - t RC .
and the time at which V out reaches any particular voltage Va may be written
t=−RC ln ((1 −Va )/0.98).
The time at which the differential output voltage V out reaches a voltage of 0.5V is
t 1 =−RC ln (0.5/0.98)
The time jitter introduced by the 2% error may then be calculated as Jitter = t 0 - t 1 = - RC ln ( 0.98 )
The 20% to 80% rise time of the differential output signal V out may be written t 20 –80 = t 80 % - t 20 % = - RC ln ( 0.2 ) - ( - RC ln ( 0.8 ) ) = - RC ln ( 0.2 / 0.8 ) = - RC ln ( 0.25 )
The percentage effect of jitter resulting from a low to high transition which occurs when the output signal is settled to within 2% of it steady state value may be calculated as % Jitter = Jitter / t 20 –80 = [ - RC ln ( 0.98 ) ] / [ - RC ln ( 0.25 ) ] = 1.46 %
This indicates that if the differential output voltage V out does not settle to within 2% of its steady state value, a jitter of greater than 1.46% of the rise and fall time results. One skilled in the art will be able to show that this calculation holds true for an early high to low transition and for any arbitrary high and low voltage levels (V OH and V OL ) for the differential output signal V out .
Reference is next made to FIG. 4, which shows the differential output signal V out , the 20% to 80% rise time of the differential output signal V out for the prior art cable driver 20 (shown in FIG. 1) and the 2% settling time (i.e. the 98% rise time, t 98% ) of the differential output signal V out . Since the 20% to 80% rise time of the cable driver must exceed the specified minimum threshold, the maximum data rate which may be transmitted using the prior art cable driver 20 will be dependent on the ratio of the 20% to 80% rise time to the 2% settling time of the differential output signal V out .
The ratio of the 20% to 80% rise time of the differential output signal V out to the 2% settling time of the differential output signal V out may be calculated t 20 –80 / t 98 % = [ - RC ln ( .25 ) ] / [ - RC ln ( 0.02 ) ] = 35.4 %
If this ratio could be increased, the maximum data rate which may be transmitted on a transmission line could also be increased, without introducing any additional electromagnetic radiation and without increasing jitter.
Reference is next made to FIG. 5, which shows an improved cable driver 120 , according to the present invention.
The improved cable driver 120 comprises an input port 122 , an output port 144 , two resistors 128 and 130 and five switching stages SS 1 , SS 2 , SS 3 , SS 4 and SS 5 coupled in series by four delay stages, D 1 , D 2 , D 3 and D 4 .
Input port 122 comprises input terminals 158 and 160 . Output port 144 comprises output terminals 146 and 148 . Resistor 128 , which has resistance R 128 , is coupled between V CC and node 148 and resistor 130 , which has resistance R 130 , is coupled between V CC and node 146 .
Resistors 128 and 130 will be chosen to match the impedance of the transmission line to which the improved cable driver 120 is coupled. This eliminates the need for emitter follower output stages, so the associated problems of ringing and overshoot are avoided.
Switching stage SS 1 comprises a current source 162 and a switch 164 . Current source 162 is coupled between switch 164 and ground. Switch 164 is responsive to a differential input signal V in received at input port 122 and may couple current source 162 to node H 1 or to node L 1 . Node H 1 is coupled to output terminal 148 and node L 1 is coupled to output terminal 146 .
Switching stages SS 2 , SS 3 , SS 4 and SS 5 each similarly comprise a current source 166 , 170 , 174 or 178 , respectively, and a switch 168 , 172 , 176 or 180 , respectively. These current sources and switches are coupled together and coupled to ground and to output terminals 148 and 146 in the same manner as current source 162 and switch 164 .
Delay stage D 1 is coupled to input port 122 at nodes 182 and 184 and provides a delayed signal V in−1 responsive to input signal V in at nodes 198 and 200 . Switch 168 is coupled to nodes 198 and 200 and is responsive to signal V in−1 and may connect current source 166 to terminals H 2 or L 2 . Delay stages D 2 , D 3 and D 4 generate sequentially delayed signals V in−2 , V in−3 and V in−4 corresponding to V in and V in−1 . They are similarly coupled between switches 168 and 172 , 172 and 176 and 176 and 180 respectively such that each subsequent switch 172 , 176 or 180 receives a signal corresponding to differential input signal V in−2 , V in−3 , V in−4 at a later time than the preceding switch.
As with the prior art cable driver 20 , the improved cable driver 120 will typically be configured to produce a differential output signal V out at output terminals 146 and 148 . The differential output terminal is defined as the difference between the voltage at output terminal 148 (V 148 ) and the voltage at output terminal 146 (V 146 ):
V
out
=V
148
−V
146
The improved cable driver operates as follows. A differential input signal V in is received at input terminals 158 and 160 and is directed to switch 164 . As with the prior art cable driver 20 , the differential input signal V in is defined as the difference between the voltage received at terminal 160 (V 160 ) and the voltage received at terminal 158 (V 158 ):
V in =V 160 −V 158 .
Switch 164 is responsive to differential input signal V in . If V in is high (i.e. V 160 >V 158 ), switch 164 will couple current source 162 to node H 1 and conversely, if V in is low (i.e. V 160 <V 158 ), switch 164 will couple current source 162 to node L 1 .
Delay stage D 1 provides a delayed signal V in−1 corresponding to input signal V in at nodes 198 and 200 . Switch 168 is responsive to signal V in−1 . If V in−1 is high, switch 168 will couple current source 166 to node H 2 and conversely, if V in−1 is low, switch 168 will couple current source 166 to node L 2 . In this manner, current sources 162 and 166 will be coupled to the same output terminal 146 or 148 .
Similarly switches 172 , 176 and 180 are responsive to the delayed signals provided by delay stages D 2 , D 3 and D 4 , respectively, and will couple current sources 170 , 174 and 178 , respectively, to the same output terminal 146 or 148 as current sources 162 and 166 .
At steady state, if V in is low, all five current sources 162 , 166 , 170 , 174 and 178 will be coupled to output terminal 148 . The voltage at terminal 148 (V 148 ) will be
V 148 =V CC −R 128 ( I 162 +I 166 +I 170 +I 174 +I 178 ).
The voltage at terminal 146 (V 146 ) will be V CC , and the differential output signal V out will be V out = V 148 - V 146 = - R 128 ( I 162 + I 166 + I 170 + I 174 + I 178 ) = V OL
If V in is high, all five current sources 162 , 166 , 170 , 174 and 178 will be coupled to output terminal 146 and the output voltage will be V out = R 130 ( I 162 + I 166 + I 170 + I 174 + I 178 ) = V OH
Assuming that the differential input signal V in is initially high, differential output signal V out will be equal to V OH . On the high to low transition of V in , switch 164 will switch current source 162 from terminal H 1 to L 1 . The voltage at terminal 146 , will rise to
V 146 =V CC −R 130 ( I 166 +I 170 +I 174 +I 178 )
and the voltage at terminal 148 will fall to
V 148 =V CC −R 128 ( I 162 ).
The differential output voltage V out will fall to V out = V 148 - V 146 = - R 128 ( I 162 ) + R 130 ( I 166 + I 170 + I 174 + I 178 ) .
Delay stage D 1 will, after its configured delay period, produce a high to low transition at terminals 198 and 200 . Switch 168 will then switch current source I 2 from terminal H 2 to terminal L 2 and the differential output voltage will fall to
V out =−R 128 ( I 162 +I 166 )+ R 130 ( I 170 +I 174 +I 178 ).
This process will continue until the delay periods of all four delay stages D 1 , D 2 , D 3 and D 4 have elapsed, all five switches 164 , 168 , 172 , 176 and 180 have respectively coupled 162 , 166 , 170 , 174 and 178 to output terminal 146 and V out has fallen to V OL , as defined above.
Reference is next made to FIGS. 6A and 6B. FIG. 6A shows the transitions of switches 164 , 168 , 172 , 176 and 180 from their respective H nodes to their respective L nodes in response to a high to low transition of the differential input signal. FIG. 6B shows the corresponding high to low transition of V out . Switches 164 , 168 , 172 , 176 and 180 are non-ideal switches with a finite transition time. The transition time of switches 164 , 168 , 172 , 176 and 180 and the delay times of delay stages D 1 , D 2 , D 3 and D 4 are preferentially chosen to ensure that the differential output signal V out is substantially linear. At the same time, the 20% to 80% rise and fall times of the differential output signal V out must exceed the specified minimum time. As shown in FIGS. 6A and 6B, if the transition time of the switching stages is too short, the output signal V out will appear as a staircase signal with each step being separated by the delay of the respective delay stages D 1 , D 2 , D 3 and D 4 . Increasing the transition time of the switches 164 , 168 , 172 , 176 and 180 will provide a smooth transition, improving the linearity of differential output signal V out , As shown in FIGS. 7A and 7B, which also shows the transitions of switches 164 , 168 , 172 , 176 and 180 and the differential output signal V out , the differential output signal V out may be made substantially linear by making appropriate choices in the design of the switching stages SS 1 , SS 2 , SS 3 , SS 4 and SS 5 and delay stages D 1 , D 2 , D 3 and D 4 . The design of these elements is described in detail below. As an example, a substantially linear differential output signal V out may be achieved if the delay time between the corresponding signals V in , V in−1 , V in−2 , V in−3 and V in−4 is 70 ps and the transition time of the switches 164 , 168 , 172 , 176 and 180 is 150 ps. This will provide a differential output signal with a transition time of approximately 220 ps.
When a low to high transition of V in occurs subsequently, switches 164 , 168 , 172 , 176 and 180 will couple their respective current sources 162 , 166 , 170 , 174 and 178 to output terminal 148 and differential output signal will return to its initial high output level V OH .
Since the high to low and low to high transitions of the differential output signal V out are substantially linear, the ratio of the 20% to 80% rise time of V out to the 2% settling time (i.e. the 98% rise time) will be t 20 –80 / t 98 = 0.6 / 0.98 = 0.612 = 61.2 % .
As described above, the 20% to 80% rise time or fall time of the differential output signal V out must exceed a minimum time period. If both the prior art cable driver 20 and the improved cable driver 120 are (1) configured to operate with this minimum 20% to 80% minimum rise/fall time and (2) receive an input which allows them the meet the requirement that the differential output signal V out must settle to with 2% of its steady state value (in order to reduce time jitter, as described above), the improved cable driver 120 will be capable of carrying a higher data rate than the prior art cable driver 20 . The ratio of the maximum data rate which may be carried by the improved cable driver 120 to the maximum data rate which may be carried by the prior art cable driver 20 may be calculated as follows:
61.2%/35.4% =1.73
Thus, the improved cable driver 120 is capable of carrying a data rate 1.73 times higher than the prior art cable driver 20 , without increasing the generation of electromagnetic radiation or increasing jitter in the differential output signal V out . One skilled in the art will recognize that if the particular application in which improved cable driver 120 requires that the jitter in the differential output signal V out be less than 1.46%, as calculated above, the benefit of the invention will be commensurately greater.
Reference is next made to FIG. 8, which shows switching stage SS 1 and delay stage D 1 in detail. Switch 164 comprises a differential amplifier stage 220 and current source 162 comprises current mirror 222 . Current mirror 222 comprises transistor Q 5 , diode connected transistor Q 6 and reference current source 224 , which are connected in the well known current mirror configuration. The bases of transistors Q 5 and Q 6 are coupled together and the emitters of transistors Q 5 and Q 6 are connected to a voltage source −V EE . The collector of transistor Q 6 is coupled to V CC through reference current source 224 . The current drawn by transistor Q 5 through differential amplifier stage 220 will depend on the current of current source 224 in known manner. Differential amplifier stage 220 comprises two transistors Q 3 and Q 4 , the emitters of which are connected together. The base of transistor Q 3 is coupled to input terminal 158 and the base of transistor Q 4 is coupled to input terminal 160 . The collector of transistor Q 3 comprises node L 1 and the collector of transistor Q 4 comprises node H 1 . The emitters of transistors Q 3 and Q 4 are coupled to the collector of transistor Q 5 .
The bases of transistors Q 3 and Q 4 are coupled to input terminals 158 and 160 , respectively and receive the differential input signal across their bases. One skilled in the art will be familiar with the operation of the differential amplifier stage 220 and the current mirror 222 and will understand the switching operation provided by the switching stage SS 1 .
Delay stage D 1 is comprised of a differential amplifier consisting of transistors Q 7 and Q 8 , resistors 226 and 228 and a current mirror comprising transistors Q 9 , diode connected transistor Q 10 and reference current source 230 . The emitters of transistors Q 7 and Q 8 are connected together and to the collector of transistor Q 9 . The base of transistor Q 9 is coupled the base of transistor Q 10 . The collector of transistor Q 10 is coupled to V CC through reference current source 230 . The emitters of the transistors Q 9 and Q 10 are connected to −V EE . The collectors of transistors Q 7 and Q 8 are coupled to a voltage source V DD through resistors 226 and 228 , respectively. Transistors Q 7 and Q 8 receive the differential input signal V in across their bases, which are connected to input terminals 160 and 158 respectively. The collectors of transistors Q 7 and Q 8 are coupled to nodes 200 and 198 respectively. One skilled in the art will understand that the operation of Q 7 and Q 8 as a differential amplifier will produce signal V in−1 at nodes 198 and 200 (as discussed above) responsive to the differential input signal V in , but delayed in time. The length of the delay will depend on the current of current source Q 9 , which will depend on the current of reference current source 230 in known manner, the resistance of resistors 226 and 228 and other characteristics of the bipolar technology in which the cable driver circuit is realized. One skilled in the art will be capable of selecting appropriate components to ensure that the transitions of the differential output signal are substantially linear.
Although the invention has been described with reference to an embodiment with 5 rise/fall time stages and 4 delay stages, the number of rise/fall time stages and delay stages may be varied to meet the operational requirements of the particular context in which the improved cable driver 120 is used. In addition, by varying the number and configuration of the switching stages and the delay stages, a non-linear differential output signal V out may be generated and in fact, any desired output wave form may be generated.
One skilled in the art will be capable of making the modifications necessary to use the improved cable driver 120 in these contexts and will recognize that these and other embodiments fall within the spirit and scope of the invention, as defined by the following claims.
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A cable driver is disclosed which provides a substantially linear output signal corresponding to an input signal received by the cable driver on a transmission line. The cable driver includes a number of switches coupled by delay elements with cause the switches to operate in a sequential order in response to an input signal. Each of the switches couples an associated current source to an output port, producing a substantially linear output signal on a transmission line connected to the output port. The substantially linearity of the output signal increases the rate at which data may be transmitted over the transmission line, while permitting the rise and fall time of a specified portion of the output signal to be controlled to ensure that electro-magnetic interference is not produced.
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FIELD OF THE INVENTION
This invention relates to the heat control of steam-heated rollers of the type generally used in paper mills to remove water from the product produced from wet pulp.
BACKGROUND OF THE INVENTION
This invention relates to control of the fluid drain and thence the temperature of steam-heated rollers. Especially but not exclusively in paper mills, a wet pulp is laid on a web and then is run over the surface of successive heated rollers to remove the water and to produce paper as a product. The flow of the pulp which is to become paper is very swift, and its path length through the machine is very long. Path velocities on the order of 35 miles per hour, widths of 24 feet or more, and roller diameters of five feet or larger are commonplace. The rollers are hollow drums to which steam is supplied, and from which condensate and steam are removed. In accordance with good thermodynamic practice, steam discharged from one roller is supplied to the next roller, often in a sequence of perhaps five rollers in a group.
The system is very massive. The mass transport is very large. In the event of failure such as breakage of the treated material or the failure of a roller or a group of rollers to perform their intended function, wastage of many tons occurs before the system can be shut down.
Paper mills are huge installations, and their capital investment is very great. A new paper mill can be expected to cost on the order of $800 million, and an older used mill, perhaps $350 million. Even these large costs do not reflect the total situation. The heavy wear to which they are subjected gives rise to a rebuilding cycle on the order of only about five years. Each five years the average paper machine will be shut in for a substantial period of time during which it is refurbished to operational standards, and at the same time is modernized to provide such advantages as may have become available since its last rebuilding.
The burden of the foregoing is that the costs of inefficiencies in these plants are literally immense. At the present time, in many paper mills that are regarded as in suitable condition, losses by way of unacceptable products approach 5% of the daily throughput. In a 1,000 ton per day mill, this amounts to 50 tons. This tonnage has consumed energy needed to drive the mill and to heat the product. Even though the scrap can be recycled, the labor and thermal energy are not recoverable. As a consequence, designers and operators of these mills are constantly alert for opportunities to reduce the generation of scrap, and to reduce the energy requirements. In fact, there are designers and rebuilders whose entire careers are occupied by redesign, improvement and refurbishment of paper mills with these objectives in mind.
What is genuinely surprising is the fact that in even the most advanced mill presently known to the inventor, control over the running conditions of the steam-heated rolls can still be improved so as to reduce the quantity of scrap produced by the mill. For example, with presently known controls, there is a substantial and continuing risk that the dryer roll may be flooded with hot water. The water greatly inhibits the heat transfer to the paper product. The present state of the art uses pressure drop across the dryer roll drain mechanism as the control reference. This is inadequate because some dryer rolls may be flooded, while adjacent dryer rolls are blowing steam through uncontrolled. Measurement of the supply steam and also of the drain steam as proposed by the instant invention provides BTU measurements needed properly to treat the paper.
At present the detection of a flooded dryer roll (which will not provide the proper drying conditions) is actually a happenstance thing. Periodically an inspector uses an infrared detector which he aims at the dryer roller to measure its temperature. He stands at a considerable distance from the roller and aims at a given spot on the rapidly rotating dryer roller. Assuming good aim and optimum conditions, a dryer roller at the wrong temperature will indeed be detected. But by the time a drop in temperature is detected, the dryer roller will be flooded with water. This causes off-specification paper to be produced that usually must be recycled with a loss of labor and energy.
However, even these proposed and imperfect results are rarely attained in mills of this type. This is because these mills are hot, humid, noisy, and very distracting places. As a consequence, a roller which is performing improperly is seldom discovered until the paper is not properly dried (scrap) or an associated large drive motor starts to overload. Meanwhile, as a precaution the entire system is often adjusted to dry the paper excessively so as to be certain the product is dried acceptably. This consumes excess energy, and can also lead to reduced production of paper.
The costs of these adverse circumstances are substantial. In a large mill, the costs of excess energy consumed but not truly needed can readily approximate $10,000 per day. The accurate control of roller conditions is, as can be seen, an objective long recognized by any prudent paper mill designer or operator.
Mills which utilize so many and such large rollers inherently must consume great amounts of energy, and for the intended applications the optimum source is steam. The properties of steam are well established, and it would seem to be a simple problem in thermodynamics to maintain the rollers in their correct condition both individually and as one of a sequence of rollers. The inefficiency of existing plants shows instead that it is not a simple matter after all, because after generations of good engineers have done their best (and produced large amounts of paper products), the problems and wastage continue to exist.
Surprisingly, the regulation of roller temperatures under the prevailing conditions by means of fluid flow measurements has not been done before, and by means of this invention, which utilizes this approach, the machines can reliably be regulated to assure that the individual rollers are indeed maintained at a proper temperature, with a proper BTU throughput.
It is an object of this invention to provide a rugged and reliable measurement and control which frustrates the flooding of a roller, or the converse, excess steam blow through, and which maintains throughput and temperature conditions to maintain a predetermined temperature while supplying the correct caloric output necessary to heat the paper while it resides on the rollers.
Importantly, this invention enables these results to be attained with the use of elegantly simple controls and minimized plumbing.
BRIEF DESCRIPTION OF THE INVENTION
This invention provides a supply steam flow meter upstream in the steam flow entering the dryer roll and a drain steam flow meter downstream in the steam flow leaving the dryer roll. Saturated steam (which may instead occasionally be superheated steam) is supplied to the inlet at an elevated pressure which by definition establishes the roller temperature. Valves upstream and downstream are set to establish flow conditions that conform to the desired flow-through of steam and condensate at the drain as the consequence of an enabling measurement made with the use of the two flow measurements from the flow meters. The differential conditions between the two flow meters reflect the fact that caloric output to the pulp stream through the roller causes condensation of some of the steam in the roller. The very substantial difference between the volume of the steam that is condensed, and the volume of the resulting condensate, enables one to calculate supply and drain steam flow, change of state, and the energy (BTU's/calories) absorbed by the product, and to adjust the mass throughput so that flooding does not occur. A functional and efficient system is thereby enabled.
The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
The figure is a schematic illustration of the presently preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the figure there is shown a steam heated roller 10 (sometimes called a "rotary drum", having an axis of rotation 11, an exterior cylindrical contact surface 12, and end plates 13. The roller is hollow, the contact surface being formed on a wall 14 of uniform thickness which is exposed to steam in the interior of the roller. Cylindrical cavity 15 (sometimes called a "steam chamber"), defined by wall 14 and end plates 13 receives steam.
A bearing (not shown) at one end, and a rotary joint 16 at the other end, support the roller for rotation around the axis. Drive means (not shown) drives the roller so it maintains a tangential velocity equal to the linear velocity of the paper product. The objective, of course, is to enable the paper product, in whatever state of water removal, to be in contact with surface 12 for a suitable period of time during which some of the water in the product is evaporated from it. The term "product" is not limited to the finally completed paper, but is intended to include its condition throughout the process, including the pulp in all of its stages.
A steam supply line 17 supplies steam to the cavity in the roller, and a drain line 18 removes condensate and residual steam from the roller. The wall of the roller is heat conductive, usually made of steel, and evaporation of water from the paper product and losses by emission result in condensation of some of the steam in the roller. The drain line includes conventional means (not shown) inside the roller which have feet or other evacuation devices to remove the condensate from the wall, and also to drain excess steam from the roller. These provisions are completely conventional and are therefore not disclosed in detail.
The drain line discharges to a collection box 19 from which condensate may be removed by a pump 20 which recycles the water. A downstream supply line 21 conveys drain steam to the next roller downstream.
This invention exercises surveillance and control over the conditions in the steam line and in the drain line. This is accomplished by providing an adjustable steam supply control valve 25 and a steam supply flow meter 26 in the supply line, and an adjustable drain control valve 27 and drain flow meter 28 in the drain line. The theory of the function of this system is based on the fact that steam throughout the system is saturataed (occasionally superheated). Therefore its temperature will be known from its pressure. The control valves, along with the usual steam controls regularly provided in any suitabiy designed system enable one to establish this pressure.
The objective of this system is to provide a predetermined BTU output through the wall of the roller. If there is an insufficient flow of steam, then soon the caloric drain will condense steam to an amount of water which will not be drained, and the roller will fill with hot water. A water-filled roller cannot produce the BTU's required. Furthermore, its mass greatly increases the load on its driving motor. Incorrect product is likely to be produced, and the overload on the drive system can lead to bearing overloads and ultimate damage to the motors.
On the other hand, too great a steam flow is likely to overdry the product, and definitely wastes energy. Clearly, a properly balanced system will provide the correct caloric output to the surface of the roller, but no more, and in so doing should be in steady flow with a roller essentially filled with steam, and with condensate withdrawn at its rate of formation.
The control valves may be any suitable adjustable steam valve such as a globe valve or a gate valve, automatically or manually operated.
The flow meters are conventional differential flow meters as described in the ASME Report on Fluid Meters, 6th edition. They operate to measure flow as a function of the differential pressure set up across an a primary element 30 such as an orifice, a nozzle, or a venturi, or the like, measured by an upstream sensor 31 and a downstream sensor 32. These flow meters are quite standard and require no detailed description here. Meters 26 and 28 are identical.
It will be observed that the flow through the steam supply flow meter 26 is entirely gaseous (it could be slightly superheated) steam. The fluid flow through drain flow meter 28 is a mixture of saturated steam and condensate. Because they both pass through the drain flow meter, the condensate will constitute a small offset to the actual drain steam flow measurement. In fact the reading will be higher than if the same amount of steam were passed through the flow meter, without the condensate. The error is small, in large part because of the substantial difference in volume of a given weight of condensate water, and of steam. This invention essentially measures the flow rate of the drain steam and compensates for the liquid phase.
In a practical system, the resulting "offset" will be about 7%, but most importantly, this offset is substantially constant from full loads through the entire range of partial loads. Therefore, knowing the offset, this simple control concept can be used with full confidence. This is an important feature, because it is unnecessary to provide means to separate the condensate from the steam ahead of the drain flow meter. To do so would require substantial piping and other features which would uneconomically enlarge both the cost and the bulk of the installation.
In operation the BTU output can be derived from the difference between the readings for the supply steam flow and for the drain steam flow. Their difference, read in weight per unit of time, gives the weight of condensate, and from a knowledge of the temperatures and pressures, the BTU provided to the roller can be calculated, again bearing in mind the inherent but constant instrument offset.
Much more to the point is that, once there is established a ratio of the two flow meter readings that results in a suitable BTU output, it is possible to monitor this ratio to assure that the desired steady state persists. Thus, reactive circuitry 45 can be connected between the two flow meters, and so long as the ratio remains within predetermined limits, the operation is acceptable.
In the event that the roller tended to flood, it would reflect insufficient drain steam flow through to meet the demands of the paper. A greatly decreased steam flow rate tnrough the drain flow meter would be registered, and this operating error could quickly be observed and corrected by adjusting the valves either manually or in response to the reactive circuitry. An excessive rate could also be observed and corrected.
This arrangement enables each roller in groups of many rollers to be monitored and controlled. Thus, a temperature profiled system can be arranged, requiring no more than valves which are always provided in the system anyway, and two conventional flow meters for each roller.
Any type of flow meter which is capable of responding to the flow of steam is useful in this invention. Preferably the meter will be the type which responds to a differential pressure, and may be considered a differential meter. These have primary elements which develop the differential pressure to be sensed. Examples of such primary elements are orifice plates, venturis, and nozzles. Flow meters utilizing these features are well known and require no detailed description here.
Underlying the operation of this system is the fact that the partial pressure of the condensate water at the flow meter is quite low, especially compared to the partial pressure of the steam phase. Thus, the offset that results from measuring the flow of a mixed phase stream is itself low enough to be tolerated in creating an effective control system.
This invention thereby provides a reliable, rugged and relatively inexpensive system to assure the operating conditions of steam heated rollers.
This invention is not to be limited by the embodiment shown in the drawings and described in the description, which is given by way of example and not of limitation, but only in accordance with the scope of the appended claims.
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A system to maintain the BTU output of a rotary drum, in which steam is supplied to the drum, and in which saturated steam and condensate is drained therefrom. An upstream flow meter and a downstream flow meter measure fluid flow, and in view of the small partial pressure of the condensate and of the large volumetric difference between the condensate and the steam which was condensed, the difference between the flow meter readings can be understood as a measure of BTU's provided as a consequence of the condensation which occurs in the drum.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National Stage of International Application No. PCT/GB2012/000076, filed Jan. 25, 2012, which claims priority from GB 1101299.4, filed Jan. 25, 2011. The entire disclosure of each of the aforesaid applications is incorporated by reference in the present application.
FIELD OF THE INVENTION
The present invention relates to oxygen sensors and their uses, and more particularly to oxygen sensors for use in product packaging for storing an article in a packaging envelope under modified atmosphere conditions.
BACKGROUND OF THE INVENTION
Modified atmosphere packaging, and in particular oxygen-free packaging, are growing in importance for extending the shelf-life of perishable products, such as foodstuffs, or providing a protective atmosphere for other types of sensitive products. However, this growth has been limited by the absence of suitable sensors that can confirm that the oxygen levels are kept at suitably low levels.
This failure in the art is a result of the diverse range of requirements for an ideal sensor. Generally, the sensors need to be inexpensive as packaging cannot incur high costs, especially for consumable products such as foodstuffs. They also need to be safe and non-toxic as they may be in contact with food and leaching may occur, or they may be at risk of accidental ingestion, for example by children. Furthermore the reaction of the sensor to a packaging failure preferably needs to be irreversible under normal packaging environment. This is important as an increase in oxygen level when a packaging failure occurs can lead to spoilage due to growth of microorganisms and it can happen that their metabolic activity restores low oxygen levels. This means that a reversible sensor may show that no packaging failure has occurred. In addition, it would be useful if the sensitivity of the sensor was tailorable as different applications of the packaging may tolerate different oxygen levels. Finally, the sensors should ideally be easy to use, providing an observable change that an unsophisticated user can appreciate, and without recourse to additional equipment, and be easy to incorporate in the packaging.
There are a few products commercially available in the market, namely, Oxy2 Dot® RedEye® and Ageless Eye™. However, they suffer from a range of significant limitations.
The Oxy2 Dot®, which is manufactured by OxySense®, is a fluorescence-based oxygen sensor. The product is a small circle that sticks to the inside of the package and the fluorescence intensity, which is inversely proportional to oxygen level, is measured by a photodetector. The two main problems with this sensor are (a) the need for expensive sensing equipment, and (b) temporary high oxygen levels may go unnoticed as the sensor operates in a reversible manner. The RedEye® operates on similar principles to the Oxy2 Dot® and, therefore, suffers from similar limitations.
The Ageless Eye™, which is manufactured by Mitsubishi Gas Chemical (MGC), changes visible colour upon oxidation. At low oxygen concentrations (<0.1%) the sensor appears pink, but when the oxygen concentration increases the colour changes gradually to blue. The limitations of this sensor are that it is not irreversible, it is expensive (60 p each) and the dye is harmful (methylene blue).
A further product is under development. A UV activated oxygen indicator is currently being developed by Mills. This sensor, which uses the same dye as Ageless Eye™ (methylene blue), is coated onto the inner side of packaging film and is only activated when exposed to UV light, which changes its colour from blue to white. When the sensor is exposed to oxygen, it regains the blue colour. The main issues with this sensor are safety issues due to the use of methylene blue, aesthetic (tainting of food), and the bleaching effect (blue to white) due to prolonged exposure to shelf light, which may lead to false negatives.
There is also a need to develop an effective oxygen sensor for use in non-food related fields, such as packaging pharmaceuticals and nutraceuticals, and for use in other fields, such as the storage of rare books and manuscripts, and for use in the packaging of high value products, such as electronic devices and components.
Oxygen sensing has been developed in other technical fields. U.S. Pat. No. 3,663,176 describes the use of metal salts of elements in Group IVB and VB of the periodic table as a colorimetric oxygen indicator in stream of alkene (olefin) in polymerization processes. US 2008/0300133 discloses an oxygen scavenger and indicator comprising three components: (a) an oxygen sorbent which is a metal or metal compound that can transfer from one oxidation state to another, (b) a redox indicator and/or complexing agent for the metal or the oxidised form of metal, and (c) at least one polymer or gel electrolyte. The oxygen indicator of this application apparently works when the oxidation of the metal causes a change in a physical property of the oxygen sorbent through a change in the interaction with the redox indicator or the complexing agent, such as a colour change.
GB 2,369,808 discloses oxygen or water sensors for food packaging based on a colour change of soluble transition metal compound, generally a soluble coordination complex.
From the discussion above, it will be apparent that the provision of an effective sensor for modified atmosphere packaging, and in particular for packaging for foodstuffs, remains an unsolved problem in the art.
SUMMARY OF THE INVENTION
Broadly, the present invention relates to oxygen sensors and their uses, and more particularly to oxygen sensors for use in product packaging for storing an article in a packaging envelope under modified atmosphere conditions wherein the oxygen sensors comprise solid poly oxo-hydroxy metal ion materials, optionally modified with one or more ligands. In some embodiments, the solid poly-oxo-hydroxy metal ion material is present in a hydrated, oxygen permeable matrix, for example formed from a material, such as gelatine. While the present invention is applicable in many technical fields, it is particularly applicable in the field of food packaging. The presence of oxygen in packaged food leads to food spoilage through enzymatic-catalysed reactions, oxidation of flavours and nutrients and/or by allowing aerobic food-spoiling microorganisms to grow. Modified-atmosphere packaging, in which the food package is flushed with an inert gas such as nitrogen or carbon dioxide, reduces oxygen levels and extends the shelf-live of food products. The market for this packaging is growing but is currently limited by the absence of cheap oxygen monitoring devices, i.e. oxygen sensors, which ensure that low levels of oxygen have been maintained during the storage and handling of the food packages. The present invention addresses this problem through the development of mineral oxo-hydroxide-based sensors that are safely disposable (e.g. are environmentally friendly), cheap to manufacture, and provide detectable changes in the presence of oxygen that are easy to read. Additionally or alternatively, the oxygen sensors of the present invention may be synthesised from food-grade GRAS reagents which makes them inherently safe for food applications.
Thus, the present invention uses solid poly oxo-hydroxy metal ion materials in contrast to the traditional coordination complexes used in US 2008/0300133 that rely on an interaction with a redox indicator to produce detectable changes in response to the presence of oxygen.
Accordingly, in a first aspect, the present invention provides an oxygen sensor comprising a solid poly oxo-hydroxy metal ion material having a transition metal ion in a first oxidation state that is capable of oxidation to a second oxidation state in response to oxygen, wherein the solid poly oxo-hydroxy metal ion material has a polymeric structure in which one or more ligands are non-stoichiometrically substituted for the oxo and/or hydroxy groups, so that exposure of the material to oxygen causes the oxidation of the metal ion in the solid poly-oxo-hydroxy material to produce a detectable change in the material. In some instances in this aspect of the present invention, the solid poly oxo-hydroxy metal ion material is present in a nanoparticulate or nanostructured form.
In a further aspect, the present invention provides an oxygen sensor comprising a solid poly oxo-hydroxy metal ion material having a transition metal ion in a first oxidation state that is capable of oxidation to a second oxidation state in response to oxygen, wherein the solid poly-oxo-hydroxy metal ion material is present in a hydrated, oxygen permeable matrix, so that oxygen permeating the matrix causes the oxidation of the metal ion in the solid poly-oxo-hydroxy material to produce a detectable change in the material.
Alternatively or additionally, the present invention provides an oxygen sensor comprising a solid oxo-hydroxy metal ion material having a transition metal ion in a first oxidation state that is capable of oxidation to a second oxidation state in response to oxygen, wherein the solid oxo-hydroxy metal ion material is present in nanoparticulate or nanostructured form so that exposure of the material to oxygen causes the oxidation of the metal ion in the solid oxo-hydroxy material to produce a detectable change in the material.
Preferably, the metal ion material used in any aspect of the present invention may be dispersed in the matrix in a nanoparticulate or nanostructured form. This helps to increase the surface area of the material that can come into contact with oxygen permeating the matrix. Preferably, in the sensors of the present invention, the metal ion material does not form a soluble complex with materials forming the matrix, as is the case in the system disclosed in US 2008/0300133.
In one embodiment, the oxygen sensor comprises a solid poly oxo-hydroxy metal ion material having a structure in which one or more ligands are non-stoichiometrically substituted for the oxo and/or hydroxy groups. As will be further explained below, this generally means that the ligands are integrated into the solid phase material and have at least some demonstrable metal-ligand bonding.
In a further aspect, the present invention provides a product packaging for storing an article in a packaging envelope under modified atmosphere conditions, wherein the product packaging comprises an oxygen sensor of the present invention within the envelope, so that oxygen leaking into the packaging envelope causes oxidation of the metal ion to produce a detectable change in the material.
In a further aspect, the present invention provides the use of an oxygen sensor as disclosed herein for detecting the leakage of oxygen into product packaging for storing an article in a packaging envelope under modified atmosphere conditions, so that oxygen leaking into the packaging envelope causes oxidation of the metal ion in the oxo-hydroxy material to produce a detectable change in the material.
In a further aspect, the present invention provides a method of detecting oxygen leaking into product packaging for storing an article in a packaging envelope under modified atmosphere conditions, the method comprising:
(a) providing an oxygen sensor of the present invention within the packaging envelope under modified atmosphere conditions, so that oxygen leaking into the packaging envelope causes oxidation of the metal ion in the oxo-hydroxy material to produce a detectable change in the material; and (b) optionally detecting the change in the material to indicate the leakage of oxygen into the packaging envelope.
In a further aspect, the present invention provides a process for producing an oxygen sensor of the present invention, the process comprising:
(a) mixing the solution comprising a transition metal ion, and optionally one or more ligands, in a reaction medium at a first pH(A) at which the components are soluble; (b) changing the pH(A) to a second pH(B) to cause a solid precipitate or a colloid of the ligand-modified poly oxo-hydroxy metal ion material to be formed; (c) separating, and optionally drying and/or formulating, the solid poly oxo-hydroxy metal ion material produced in step (b); and (d) optionally processing the solid poly oxo-hydroxy metal ion material so that a nanoparticulate or nanostructured material is produced and/or (e) optionally carrying our one or more post production treatments such as heating.
As explained in more detail below, the process may involve the further step of formulating the solid poly oxo-hydroxy metal ion materials in a matrix by mixing the material, or a precursor thereof, with one or more matrix forming materials to form a hydrated, oxygen permeable matrix capable of sensing oxygen. Alternatively or additionally, the one or more matrix forming materials may be introduced at the time of the reaction to precipitate the solid poly oxo-hydroxy metal ion material so that the process comprises the step of precipitating the solid poly oxo-hydroxy metal ion material in the presence of a solubilized matrix material and solidifying the resulting material to produce a solid poly oxo-hydroxy metal ion material in a semi-solid matrix.
The present invention is based on the recognition that materials containing a redox metal (M r ) can convert oxidation state when exposed to a new environment of differing oxygen content or oxidative/reductive potential and that in some cases this will lead to a change in colour in M r -containing materials. The present invention therefore utilises M r -containing materials as sensors of a changing oxygen or oxidative environment. These materials have proven to be highly specific M r containing materials that are capable of fulfilling one or more of the general requirements of oxygen sensors. These requirements include (1) the need to be inexpensive as usually these are “one off” sensors, (2) environmentally and biologically compatible, especially for uses involving foodstuffs, (3) tailorable to the different sensing needs of different environments and (4) easily read and interpreted as a sensor, preferably without expensive equipment or user training. Generally, for sensors in a solid or semi-solid format, the sensor will include a degree of hydration to facilitate redox activity, while in solution, suspension or gel phase, the sensor is preferably dispersed adequately to provide a large enough surface area that enables sensitive detection. The present inventors have found that some specific manipulation of M r poly oxo-hydroxides, equally referred to as hydroxy-oxides in the art, fulfils all of the above criteria and provides for sensitive and tailorable sensing of an oxygen environment. Moreover, they have identified that crystalline forms, namely Mr oxides or Mr hydroxides can also be manipulated in such a fashion to allow for useful oxygen sensing. Thus, Mr oxo-hydroxides in their early stages of self-assembly that is polymeric or cross-linked polymeric (denoted “poly”) or their more crystalline forms (denoted oxide or hydroxide) can be modified and/or manipulated to usefully sense oxygen levels. it may be clear to those skilled in the art that modification of the materials is likely to lead to a reduction in their crystallinity or an increase in their amorphous nature as described in more detail below.
Embodiments of the present invention will now be described by way of example and not limitation with reference to the accompanying figures and examples.
“and/or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example “A and/or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein.
Unless context dictates otherwise, the descriptions and definitions of the features set out above are not limited to any particular aspect or embodiment of the invention and apply equally to all aspects and embodiments which are described.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 a . Phase distribution during the synthesis of Fe 2+ 40 OH under nitrogen, where the nomeclature used to describe these materials is described below.
FIG. 1 b . Particle size of Fe 2+ 40 OH prior to incorporation into a gelatine showing that, without modification, it would form large agglomerates (N=3).
FIG. 1 c . TEM image of 2-15 nm Fe 2+ 40 OH nanoparticles dispersed in a gelatine matrix. The nanoparticles (shown as small dark rods in the TEM image) were produced and incorporated in a gelatine matrix as described in Example 8 and then allowed to oxidise by exposure to air.
FIG. 2 a . Phase distribution during the synthesis of Fe 2+ 40 OH-T 200 .
FIG. 2 b . Particle sizing for Fe 2+ 40 OH-T 200 nanoparticles after synthesis (N=3).
FIG. 3 . Phase distribution during the synthesis of Fe 2+ 40 OH-T 200 Succ 200 under nitrogen.
FIG. 4 . Particle sizing for Cu 2+ 20 OH-Cys 20 nanoparticles after synthesis (N=3).
DETAILED DESCRIPTION
The Metal Ion (M)
The present invention may employ solid poly oxo-hydroxy metal ion materials as the source of the element of the oxygen sensor that responds to the presence of oxygen. These may or may not be solid ligand-modified poly oxo-hydroxy metal ion materials. The production and characterisation of solid ligand-modified poly oxo-hydroxy metal ion materials is disclosed in our earlier application WO 2008/096130, expressly incorporated by reference in its entirety, and these approaches may also be employed for the production of solid poly oxo-hydroxy metal ion materials, i.e. materials in which ligands are not incorporated into the material. In the materials where ligands are incorporated, the solid ligand-modified poly oxo-hydroxy metal ion materials may be represented by the non-stoichiometric formula (M x L y (OH) n ), where M represents one or more metal ions, L represents one or more ligands and OH represents oxo or hydroxy groups, depending on whether the groups are bridging (oxo groups) or surface groups in the solid oxo-hydroxide material. As is well known in the art, non-stoichiometric compounds are chemical compounds with an elemental composition that cannot be represented by a ratio of well-defined natural numbers, i.e. the x, y and n subscripts in the formula above will not necessarily all be natural numbers, even though the materials can be made in a reproducible manner and have consistently reproducible properties.
Conveniently, the solid poly oxo-hydroxides may be formed when the metal ion, originally present in the form of a salt, is dissolved and then induced to form poly oxo-hydroxy materials. This may optionally take place in the presence of one or more ligands (L) and lead to some of the ligand becoming integrated into the solid phase through formal M-L bonding (termed “ligand bonding”), i.e. not all of the ligand (L) is simply trapped in or adsorbed onto the bulk material. The bonding of the metal ion in the materials can be determined using physical analytical techniques such as infrared spectroscopy where the spectra will have peaks characteristic of the bonds between the metal ion and the ligand (L), as well as peaks characteristic of other bonds present in the material such as M-O, O—H and bonds in the ligand species (L). Preferred metal ions (M) are biologically compatible under the conditions for which the materials are used and are readily precipitatable from aqueous solution by forming oxo-hydroxides.
In the present invention, the materials used to form the sensors need to have at least two oxidation states and to produce a detectable change, preferably a visible colour change or a UV-visible change, where the transition metal ion in the materials is oxidised from a first lower oxidation state to a second higher oxidation state, in response to exposure to oxygen or an oxidising environment. It is also preferred that they are biologically compatible materials, especially for applications where they are used in proximity to foodstuffs. These factors mean that the sensors of the present invention are preferably based on transition metal oxo-hydroxides as they typically have the properties required and have the added advantages of being produced by a simple method, easy to incorporate in a semi-solid matrix, safe and undergoing irreversible changes upon exposure to oxygen (under normal packaging conditions). Examples of metal ions include copper, iron, chromium, vanadium, manganese, titanium, cobalt, molybdenum and/or tungsten. Some preferred examples of metal oxidation states that produce the colour changes that may be used in the present invention include: iron (Fe 2+ to Fe 3+ ), copper (Cu + to Cu 2+ ) and cobalt (Co 2+ to Co 3+ ), all of which have the advantage of being non toxic in both oxidation states. It is also preferred that the change in the oxidation state of the metal ion that leads to the colour change is irreversible, or at least is irreversible under the conditions in which it is employed as an oxygen sensor. In some embodiments, more than one type of metal ion (2, 3, 4 or more) may be used.
Without modification, the primary particles of the materials used herein have metal oxide cores and metal hydroxide surfaces and within different disciplines may be referred to as metal oxides or metal hydroxides. The use of the term ‘oxo-hydroxy’ or ‘oxo-hydroxide’ is intended to recognise these facts without any reference to proportions of oxo or hydroxy groups. Hydroxy-oxide could equally be used therefore. As described above, the materials of the present invention that are ligand doped are altered at the level of the primary particle of the metal oxo-hydroxide with at least some of the ligand L being introduced into the structure of the primary particle, i.e. leading to doping of the primary particle by the ligand L.
The primary particles of the solid poly oxo-hydroxy metal ion materials described herein are produced by a process referred to as precipitation. The use of the term precipitation often refers to the formation of aggregates of materials that do separate from solution by sedimentation or centrifugation. Here, the term “precipitation” is intended to describe the formation of all solid phase material, including aggregates as described above and solid materials that do not aggregate but remain as non-soluble moieties in suspension, whether or not they be particulate, e.g. nanoparticulate or nanostructured. These forms of the materials have the advantage that the materials can readily be dispersed in a matrix or used in powder form, with high surface areas for reaction with oxygen. The skilled person can readily determine whether materials are nanoparticulate or nanostructured, for example using techniques such as dynamic light scattering, or an equivalent technique, if present as aqueous suspension, or as determined using TEM, or an equivalent technique, if as a powder or in a matrix. Preferably, nanostructured materials include materials whose structural elements—clusters, crystallites or molecules—have dimensions in the 1 to 100 nm range.
In the present invention, reference may be made to the metal oxo-hydroxides having polymeric structures that generally form above the critical precipitation pH. As used herein, this should not be taken as indicating that the structures of the materials are polymeric in the strict sense of having a regular repeating monomer unit because, as has been stated, ligand incorporation (where applicable) is, except by coincidence, non-stoichiometric. The ligand species is introduced into the solid phase structure by substituting for oxo or hydroxy groups leading to a change in solid phase order. The polymeric nature of oxo-hydroxide metal ion materials is discussed in Flynn, Chem. Rev., 84: 31-41, 1984. Alternatively or additionally, for the ligand modified material used in accordance with the present invention, there may be a decrease in the crystallinity of the structure of the material or increase in the disorder that can be determined by high resolution transmission electron microscopy. High resolution transmission electron microscopy allows the crystalline pattern of the material to be visually assessed. It can indicate the primary particle size and structure (such as d-spacing) and give some information on the distribution between amorphous and crystalline material. Using this technique, it is apparent that the chemistry described above increases the amorphous phase of our described materials compared to corresponding materials without the incorporated ligand. This may be especially apparent using high angle annular dark field aberration-corrected scanning transmission electron microscopy due to the high contrast achieved while maintaining the resolution thus allowing the surface as well as the bulk of the primary particles of the material to be visualised.
The reproducible physico-chemical property or characteristic of the materials of the present invention will be dependent on the application for which the material is intended. Examples of the properties that can be usefully modulated using the present invention include: particle size, light absorbing/reflecting properties, hardness-softness, colour, redox capability, dissolution and encapsulation properties. In this context, a property or characteristic may be reproducible if replicate experiments are reproducible within a standard deviation of preferably ±20%, and more preferably ±10%, and even more preferably within a limit of ±5%.
The Ligand (L)
In embodiments of the present invention in which the oxo-hydroxy metal ion materials used to form the oxygen sensors are ligand modified, the solid phase ligand-modified poly oxo-hydroxy metal ion species are represented by the formula (M x L y (OH) n ), where L represents one or more ligands or anions that can be incorporated into the solid phase ligand-modified poly oxo-hydroxy metal ion material. By way of example, the ligands may be used to modulate one or more of the following properties: the colour of the material before and after exposure to oxygen, the rate of (colour) change in response to oxygen, the sensitivity of the response to oxygen, i.e. the level of oxygen, for example less than 0.1%, or less than 0.5%, or less than 1.0% or less than 5.0%, needed to induce the detectable change or the kinetics of the response to oxygen or an oxidising environment.
In the materials described herein, preferred examples of the ligands may include one or more of the following types of ligand.
(a) a classical anion ligand selected from phosphate, sulphate, silicate, selenate and/or bicarbonate; and/or (b) a food additive ligand, such as maltol and ethyl maltol; and/or (c) an amino acid ligand, such as tryptophan, glutamine or histidine; and/or (d) a nutrient-based ligand, such as folate, ascorbate or niacin; and/or (e) a carboxylic acid ligand, such as gluconic acid or lactic acid; and/or (f) pendant groups from a semi-solid matrix, e.g. amino acid side chains of gelatin.
Carboxylic acid ligands may be employed, such as linear dicarboxylic acid ligands. Examples of these include ligands represented by the formula HOOC—R 1 —COOH, where R 1 is an optionally substituted alkyl, alkenyl or alkynyl group, or an ionised form thereof, e.g. R 1 is a C 1-10 alkyl group, wherein R 1 is optionally substituted with one or more hydroxyl groups. Specific examples of these ligands include succinic acid, malic acid, adipic acid, glutaric acid, pimelic acid, citric acid, aspartic acid or tartaric acid, or an ionised forms thereof, i.e. where the ligand is succinate, malate, adipate, glutarate, pimelate, citrate, aspartate or tartrate.
Whether the carboxylic acid ligand is present as the acid or is partially or completely ionised and present in the form of a carboxylate anion will depend on a range of factors such as the pH at which the material is produced and/or recovered, the use of post-production treatment or formulation steps and how the ligand becomes incorporated into the poly oxo-hydroxy metal ion material. In some embodiments, at least a proportion of the ligand will be present in the carboxylate form as the materials are typically recovered at pH>4 and because the interaction between the ligand and the positively charged metal ion would be greatly enhanced by the presence of the negatively charged carboxylate ion. For the avoidance of doubt, the use of carboxylic acid ligands in accordance with the present invention covers all of these possibilities, i.e. the ligand present as a carboxylic acid, in a non-ionised form, in a partially ionised form (e.g., if the ligand is a dicarboxylic acid) or completely ionised as a carboxylate ion, and mixtures thereof.
Without wishing to be bound by any particular theory, the present inventors believe that the ligand may be provided as pendant groups from matrix material in which the metal oxo-hydroxide is immobilised and/or dispersed. For example, a semi-solid matrix such as gelatine may be used to immobilise and disperse the sensors such that some of side chains of the amino acids in gelatin may be incorporated in surface of primary particle of the poly oxo-hydroxy metal ion material, thus altering its physicochemical properties.
Typically, ligands are incorporated in the solid phase poly oxo-hydroxy metal ion materials to aid in the modification of a physico-chemical property of the solid material, e.g. as compared to a poly oxo-hydroxylated metal ion species in which the ligand(s) are absent. In some embodiments of the present invention, the ligand(s) L may also have some buffering capacity. Examples of ligands that may be employed in the present invention include, but are by no means limited to: carboxylic acids such as adipic acid, glutaric acid, tartaric acid, malic acid, succinic acid, aspartic acid, pimelic acid, citric acid, gluconic acid, lactic acid or benzoic acid; food additives such as maltol, ethyl maltol or vanillin; ‘classical anions’ with ligand properties such as bicarbonate, sulphate, nitrite, nitrate and phosphate; mineral ligands such as silicate, borate, molybdate and selenate; amino acids such as tryptophan, glutamine, proline, valine, or histidine; and nutrient-based ligands such as folate, ascorbate, pyridoxine or niacin or nicotinamide. Typically ligands may be well recognised in the art as having high affinity for a certain metal ion in solution or as having only low affinity or not be typically recognised as a ligand for a given metal ion at all. However, we have found that in poly oxo-hydroxy metal ion materials, ligands may have a role in spite of an apparent lack of activity in solution. Typically, one ligand or two ligands of differing affinities for the metal ion are used in the production of these materials although zero, one, two, three, four or more ligands may be useful in certain applications.
For many applications, ligands need to be biologically compatible under the conditions used and generally have one or more atoms with a lone pair of electrons at the point of reaction. The ligands include anions, weak ligands and strong ligands. Ligands may have some intrinsic buffering capacity during the reaction.
The ratio of the metal ion(s) to the ligand(s) (L) is also a parameter of the solid phase ligand-modified poly oxo-hydroxy metal ion materials that can be varied according to the methods disclosed herein to vary the properties of the materials. Generally, the useful ratios of M:L will be between 10:1, 5:1, 4:1, 3:1, 2:1 and 1:1 and 1:2, 1:3, 1:4, 1:5 or 1:10.
Throughout the examples, the M i+ j OH-L k nomenclature was adopted to describe the preparation for ligand-modified poly oxo-hydroxy transition metal materials; where 1) M refers to the transition metal, i+ to its valence, and j its concentration in the initial solution prior to synthesis and 2) L refers to a ligand and k to its concentration. There is no limit to the number of ligands and where no ligand was present the nomenclature used was M i+ j OH. for example, the nanoparticulate poly oxo-hydroxy material defined as Fe 2+ 40 OH-Tart 200 was prepared from an initial solution that contained 40 mM ferrous iron and 200 mM tartaric acid. Additional to the modified or unmodified poly-oxo-hydroxy materials produced for oxygen sensing, it was shown that more crystalline analogues, namely hydroxides and oxides may also be employed. These more crystalline structures may be initially similarly prepared through aqueous precipitation in the presence of ligand but reacting conditions are chosen to ensure crystallinity is achieved, which typically is assessed through X-ray diffraction measurements. It will however be clear to those in the art that additional methods exist for the conversion of poly oxo-hydroxy phases to crystalline phases including the use of heat.
Producing and Processing the Materials Used to Make Oxygen Sensors
Generally, the materials of the present invention may be produced by a process comprising:
(a) mixing the solution comprising transition metal ion and optionally one or more ligands in a reaction medium at a first pH(A) at which the components are soluble; (b) changing the pH(A) to a second pH(B) to cause a solid precipitate or a colloid of the optionally ligand-modified poly oxo-hydroxy metal ion material to be formed; (c) separating, and optionally drying and/or formulating, the solid poly oxo-hydroxy metal ion material produced in step (b); and (d) optionally processing the solid poly oxo-hydroxy metal ion material so that a nanoparticulate or nanostructured material is produced; and/or (e) optionally carrying our one or more post production treatments such as heating.
In cases where the ligands are provided by the materials forming a semi-solid matrix, the process may involve the step of precipitating the solid poly oxo-hydroxy metal ion material in the presence of one or more solubilized matrix materials and solidifying the resulting material to produce a solid poly oxo-hydroxy metal ion material in a semi-solid matrix. While not wishing to be bound by any particular theory, the present inventors believe that in such materials the pendant groups from the semi-solid matrix are capable of acting as ligands in the solid poly oxo-hydroxy metal ion materials.
It will be apparent that as the materials used to form the oxygen sensors are oxidisable in the presence of atmospheric oxygen, it is advisable to prepare them under an inert atmosphere or reduced oxygen conditions. Examples of other conditions that may be employed include the following using a first pH(A) which is less than 2.0 and the second pH(B) which is between 3.0 and 12.0, preferably between 3.5 and 8.0, and more preferably between 4.0 and 6.0, and carrying out the reaction at room temperature (20-25° C.). In general, it is preferred that in step (a), the solution contains 20 to 100 mM Fe 3+ and 0 to 250 mM of a suitable carboxylic acid ligand, and more preferably about 40 mM Fe 3+ and <100 mM of the ligand. If a ligand is used then a preferred ligand is tartaric acid.
The separation of a candidate material may then be followed by one or more steps in which the material is characterised or tested. Examples of further steps or post production treatments include, but are not limited to: heating, washing, centrifugation, filtration, spray-drying, freeze-drying, vacuum-drying, oven-drying, dialysis, milling, granulating, encapsulating, embedding (e.g. in gelatine), tableting, mixing, compressing, nanosizing and micronizing.
When these materials are used as oxygen sensors, the further steps include forming the solid poly oxo-hydroxy metal ion material into the format in which it is to be employed as an oxygen sensor. By way of example, the solid poly oxo-hydroxy metal ion material may be dispersed in matrix forming materials such as gelatine to form a semi-solid matrix, mixed with water to form an aqueous suspension, or coated or spray dried on a substrate to provide a sensor in the form of a powder coating.
It should be noted that different sizes and shapes of sensors may be used to control sensing time. For example, sensing materials produced in shallower moulds, than those described herein, will change colour faster, since oxygen will permeate shorter distances through the semisolid matrix before reaching the entirety of the sensing material.
Hydroxy and Oxo Groups
The present invention may employ any way of forming hydroxide ions at concentrations that can provide for hydroxy surface groups and oxo bridging in the formation of these poly oxo-hydroxy materials. Examples include but are not limited to, alkali solutions such as sodium hydroxide, potassium hydroxide and sodium bicarbonate, that would be added to increase [OH] in an ML mixture or M (+) solution, or acid solutions such as mineral acids or organic acids, that would be added to decrease [OH] in an ML mixture or M (+) solution.
The conditions used to produce the compositions of the present invention may be tailored to control the physico-chemical nature of the precipitate, or otherwise assist in its collection, recovery or formulation with one or more excipients. This may involve purposeful inhibition of agglomeration, or the use of drying or grinding steps to subsequently affect the material properties. However, these are general variables to any such system for solid extraction from a solution phase. After separation of the precipitated material, it may optionally be dried before use or further formulation. The dried product may, however, retain some water and be in the form of a hydrated solid phase ligand-modified poly oxo-hydroxy metal ion material. It will be apparent to those skilled in the art that at any of the stages described herein for recovery of the solid phase, excipients may be added that mix with the solid poly oxo-hydroxy metal ion material, but do not modify the primary particle and are used with a view to optimising formulation for the intended function of the material. Examples of these could be, but are not limited to, glycolipids, phospholipids (e.g. phosphatidyl choline), sugars and polysaccharides, sugar alcohols (e.g. glycerol), polymers (e.g. polyethyleneglycol (PEG)) and taurocholic acid.
Uses
The oxygen sensors of the present invention may be employed in a range of applications, in particular in the area of packaging and storage, especially where the storage is under modified atmosphere conditions that generally use nitrogen and/or carbon dioxide in a packaging envelope. Accordingly, the sensors may be used for packaging and/or storing products as diverse as food products, pharmaceutical products, nutraceutical products, documents, books or manuscripts, or electronic devices or components.
Materials and Methods
All chemicals were purchased from Sigma Aldrich (Dorset, UK), except uncoloured beef gelatine, which was from a commercial supplier (Oetker).
Synthesis of Metal Oxo-Hydroxides for Use as Oxygen Sensors
The metal oxo-hydroxides described herein are produced by raising the pH of an initial solution containing, at least, a soluble transition metal in a low oxidation state that can undergo oxidation to a higher oxidation state, such as Fe 2+ or Cu + . This initial solution is typically acidic, at 1.0>pH>7.0, but higher pHs can also be used, providing that the metal can remain soluble under such initial conditions. This initial solution can optionally contain one or one or more ligands of the types described herein such as tartaric acid or succinic acid. Furthermore, an electrolyte, such as NaCl or KCl, can also be added to the initial solution. Subsequently, an oxo-hydroxide material is formed through a process of colloid formation and/or precipitation by gradually increasing the pH (e.g. NaOH) until a suitable pH is achieved. Precipitation is typically carried out at room temperature (20-25° C.), but higher temperatures can also be used, if required. Depending on the intended application, reducing compounds, including reducing sugars such as glucose or fructose can be added at any point during the synthesis process for the purpose of tailoring the sensitivity of the materials to oxygen. Finally, the mineral formed can be recovered through a range of strategies dependent on the nature of the mineral and the intended application. Note that the synthetic process should be carried out, preferably, under low oxygen conditions since this prevents the oxidation of the initial soluble metal or the subsequently produced metal oxo-hydroxide. Low oxygen conditions can be achieved through a range of strategies, such as nitrogen flow, that are not described herein. The synthesis of more crystalline sensors, alternatively the conversion of previously produced amorphous materials described elsewhere in the examples to more crystalline phases can be achieved using similar conditions to those described above. However, higher pH's (pH>11) and/or higher temperatures (>60° C.) may be employed in their synthesis.
Post-Synthesis Recovery and Testing
The techniques used for the post-synthesis recovery of metal oxo-hydroxides of the present invention was dependent on the application and nature of the minerals synthesised. The metal oxo-hydroxides can be recovered by a range of methods such as filtration or centrifugation. In examples below, the metal oxo-hydroxides were tested as (i) aqueous suspensions, (ii) dry powders, or (iii) as part of a semi-solid matrix.
Aqueous Suspensions
Upon synthesis, nanoparticulate metal oxo-hydroxides remain stable in suspension and can be used directly for oxygen sensing. Upon exposure to atmospheric oxygen, or any other source of oxygen, the nanoparticulate material undergoes a process of oxidation with an associated change in colour or UV absorbance change that can be monitored.
Dry Powders
Upon synthesis, metal oxo-hydroxides can be dried and used for oxygen sensing as dry powders. The metal oxo-hydroxide powder can be dried directly from a final suspension or from a pellet obtained by centrifugation, filtration, or ultrafiltration. Upon exposure to atmospheric oxygen, or any other source of oxygen, the dry material undergoes a process of oxidation with an associated change in colour that can be used for oxygen sensing. The powders may also be incorporated in paint or spray coating compositions for ease of application.
Semi-Solid Matrix
Upon synthesis, the metal oxo-hydroxides can be incorporated into a semi-solid matrix, such as a gelatine matrix, that immobilises and disperses the material in a nanoparticulate form. It may also disperse materials which, in the absence of semi-solid matrix, would have remained as micron-sized agglomerates. By way of example, the matrix can be produced by dissolving a gelatine powder such as beef gelatine in an aqueous suspension of metal oxo-hydroxides and subsequently cooling it down, resulting in the formation of a semi-solid matrix. Alternatively, the matrix may be produced as part of the reaction that is used to form the metal oxo-hydroxide. Conveniently, the gelatine is used in an amount between 10-20% w/w. Upon exposure to atmospheric oxygen, or any other source of oxygen, the metal oxo-hydroxide, which is within the semi-solid matrix undergoes a process of oxidation with an associated change in colour that can be used for oxygen sensing.
Examples of materials that may be used as semi-solid matrices for retaining the oxygen sensing materials of the present invention in a disperse and, preferably, nanoparticulated form include hydrocolloids or hydrogels from biological sources such as, but not limited to:
Gelatine (e.g. beef, pork), Pectins, Starches (e.g. maize, wheat, tapioca, potato, etc), starch derivatives (e.g., Carboxy Methyl Starch, Starch Phosphate), cellulose, cellulose derivatives (e.g. Hydroxyethyl Cellulose, carboxymethylcellulose), Plant Gums (e.g. Arabic, Guar Karaya, Locust bean, Tragacanth, Psyllium seed, Quince seed, xanthan, larch, gatti), algae-derived gums (Alginate, Carrageen, agar, agarose, Furcellaran), bacteria-derived sugars (e.g. dextran), or chitosans.
Hydrocolloids or hydrogels from synthetic organic polymers such as, but not limited to, poly(vinyl alcohol) [PVA], poly(acrylic acid) [PAA], poly(ethylene glycol) [PEG] poly(acrylonitrile) [PAN].
Hydrocolloids or hydrogels from inorganic polymers such as, but not limited to, silicate, silicon dioxide, magnesium aluminium silicate, other silicon based gels, aluminium hydroxide, bentonite, other aluminium based gels, or borate based gels.
One consequence of the inclusion of the materials in matrices is that the present inventors have found that some variation in the colour of the sensor may be engineered through the choice of matrix material and the conditions (such as pH) used to make the oxygen sensor. This provides a further means in addition to the use of ligand modification discussed above to tailor different oxygen sensors for particular applications. By way of example, if gelatine were added to a suspension of Fe 2+ 40 OH the semi-solid matrix containing ferrous nanoparticles would appear intense bright green whereas the suspension would appear darker (blacker) green. Interestingly, once oxidised the gelatine-based matrix would become bright red whereas the gelatine-free suspension would become brown/orange.
Phase Distribution During Synthesis
A similar procedure to that described above in “Synthesis of metal oxo-hydroxides for use as oxygen sensors” was carried out except that several aliquots were collected at different pH's during synthesis. First, an initial aliquot was also collected for analysis of the “starting metal” concentration. Next the pH was slowly increased by drop-wise addition of a concentrated solution of NaOH with constant agitation until the mixture reached a basic pH (generally >8.0). At different points during the titration, a homogeneous aliquot (1 mL) of the mixture was collected and transferred to an Eppendorf tube. Any centrifugable phase formed was separated from the solution by centrifugation (10 minutes at 13000 rpm). The iron concentration in the supernatant fraction was then determined by ICPOES. To differentiate between soluble iron and particulated non-centrifugable iron (generally <15 nm diameter nanoparticles) in the supernatant, at each time point, each aliquot was also ultrafiltered (Vivaspin 3,000 Da molecular weight cut-off polyethersulfone membrane, Cat. VS0192, Sartorius Stedium Biotech GmbH, Goettingen, Germany) and again analysed by ICPOES.
Inductively Coupled Plasma Optical Emission Spectrometry Analysis (ICPOES)
Metal contents of solutions were measured using a JY2000-2 ICPOES (Horiba Jobin Yvon Ltd., Stanmore, U.K.). Solutions were diluted in 1-7.5% nitric acid prior to analysis.
TEM Analysis
The normal fixation pellet was then dehydrated through the alcohol/acetylnitrile gradient before being fixed in non-aqueous Quettol resin for 7 days. The non-aqueous pellet was resuspended straight into 100% ethanol, overnight, followed by resuspension in acetylnitrile and finally resin. The resultant resin embedded pellets were sectioned in 100 nm thick sections on 400 mesh copper grids for TEM analysis.
Oxygen Analysis
Oxygen levels were monitored using an oxygen meter (Rapidox 1100, Cambridge Sensotec, Cambridge, UK).
Particle Size Analysis
The hydrodynamic particle size of nanoparticulate suspensions was determined by dynamic light scattering (DLS), using a Zetasizer Nano-ZS (Malvern Instruments, UK). The hydrodynamic particle size of the larger agglomerates was determined by static light diffraction (SLD), using a Mastersizer 2000 (Malvern Instruments, UK).
EXAMPLES
Example 1
Ferrous Oxo-Hydroxide, Fe 2+ 40 OH
All solutions/suspensions were bubbled with nitrogen before and throughout the synthesis to achieve low oxygen conditions. A ferrous solution was prepared by adding ferrous sulphate to water that had been previously acidified with hydrochloric acid. The final iron concentration was 40 mM and the pH was generally below 4.0 and usually about 2.0. Once all of the ferrous salt dissolved, the pH was raised with a 5M NaOH solution to pH 7.0-9.0, usually 8.0, during which a green precipitate consisting of micron sized agglomerates, i.e. ferrous oxo-hydroxide, was formed. Finally, this material was incorporated as a nanoparticulate dispersion in a semi-solid matrix.
Example 2
Nanoparticulate Tartrate Modified Ferrous Oxo-Hydroxide, Fe 2+ 40 OH-T 200
All solutions/suspensions were bubbled with nitrogen before and throughout the synthesis to achieve low oxygen conditions. A ferrous solution was prepared by adding ferrous sulphate to water that had been previously acidified with hydrochloric acid and agitated until all of the ferrous salt dissolved. This solution was then added to another solution containing tartaric acid. The solution obtained from mixing the two solutions contained 40 mM iron and 200 mM tartaric acid, and its pH was generally below 4.0 and usually about 2.0. The pH was then raised with a 5 M NaOH solution to pH 7.0-9.0, usually 8.0, during which a green nanoparticulate suspension, i.e. ferrous oxo-hydroxide nanoparticles, was formed. Finally, this suspension was used directly as a sensor, recovered through filtration for other oxygen sensing methods, or, preferably, incorporated as a nanoparticulate dispersion in a semi-solid matrix.
Example 3
Nanoparticulate Tartrate Modified Ferrous Oxo-Hydroxide, Fe 2+ 40 OH-T 120
Example 2 was repeated using 120 mM tartaric acid as the ligand instead.
Example 4
Nanoparticulate Tartrate- and Succinate-Modified Ferrous Oxo-Hydroxide, Fe 2+ 40 OH-T 200 Succ 200
Example 2 was repeated using 200 mM succinic acid in addition to 200 mM tartaric acid.
Example 5
Succinate-Modified Ferrous Oxo-Hydroxide, Fe 2+ 40 OH-Succ 200
All solutions/suspensions were bubbled with nitrogen before and throughout the synthesis to achieve low oxygen conditions. A ferrous solution was prepared by adding ferrous sulphate to water that had been previously acidified with hydrochloric acid and agitated until all of the ferrous salt dissolved. This solution was then added to another solution containing succinic acid. The solution obtained from mixing the two solutions contained 40 mM iron and 200 mM succinic acid, and its pH was about 2.0. The pH was then raised with a NaOH solution to pH 6.5-9.0, usually 8.0, during which a green precipitate, i.e. succinate modified ferrous oxo-hydroxide, was formed. Finally, this suspension was used directly as a sensor, recovered through filtration for other oxygen sensing methods, or, preferably, incorporated as a nanoparticulate dispersion in a semi-solid matrix.
Example 6
Ferrous Oxo-hydroxide, Fe 2+ 40 OH Produced with Disodium Carbonate
A ferrous oxo-hydroxide material was prepared as in Example 1 and except 2.5M Na 2 CO 3 was used instead of 5M NaOH. Finally, this material was incorporated as a nanoparticulate dispersion in a semi-solid matrix.
Example 7
Dry Nanoparticulate Tartrate Modified Ferrous Oxo-hydroxide, Fe 2+ 40 OH-T 200
A nanoparticulate suspension was prepared as in Example 2. This suspension was then evaporated in a rotavapor at 60° C. under vacuum. Once dry the powder was ground and could be used for sensing oxygen.
Example 8
Ferrous Oxo-Hydroxide Dispersed in a Gelatin Semi-Solid Matrix
The following process was carried out under a nitrogen atmosphere. A ferrous oxo-hydroxide material was prepared as described in Example 1 or 5. Next, beef gelatine (15% w/w) was added to this suspension while stirring. Then, the mixture was heated to 40° C. to dissolve the gelatine. Once the gelatine was fully dissolved, the pH was re-adjusted back to its original level with a NaOH solution. Finally, a semi-solid matrix that immobilised and dispersed the ferrous oxo-hydroxide into nanoparticles was formed by cooling this suspension to room temperature. Note that different sizes and shapes of sensors could be achieved by transferring aliquots of the final suspension to suitably shaped and sized moulds prior to cooling.
Example 9
Nanoparticulate Ferrous Oxo-Hydroxide Immobilised in a Gelatin Semi-Solid Matrix
The following process was carried out under a nitrogen atmosphere. A nanoparticulate ferrous oxo-hydroxide was prepared as described in the Examples 2, 3 or 4. Next, beef gelatine (15% w/w) was added to this suspension while stirring. Then, the mixture was heated to 40° C. to dissolve the gelatine. Once the gelatine was fully dissolved, the pH was re-adjusted back to its original level with a NaOH solution. Finally, a semi-solid matrix that immobilised the ferrous oxo-hydroxide nanoparticles was formed by cooling this suspension to room temperature.
It should be noted that different sizes and shapes of sensors could be achieved by transferring aliquots of the final suspension to suitably shaped and sized moulds prior to cooling. As shown in FIGS. 1 to 1 b , Fe 40 OH tends to form agglomerates in the absence of a matrix such as gelatin, but when incorporated in a matrix material, the physicochemical effect of matrix results in physically disperse particles at sizes below 100 nm.
Example 10
Nanoparticulate Tartrate Modified Ferrous Oxo-Hydroxide Dispersed in a Hydroxyethyl Cellulose Semi-Solid Matrix
The following process was carried out under a nitrogen atmosphere. A nanoparticulate ferrous oxo-hydroxide material was prepared as described in Example 2. Next, the suspension was heated to 40° C. and then hydroxyethyl cellulose (10% w/w) was added to this suspension while stirring. A semi-solid matrix, that immobilised the ferrous oxo-hydroxide particles, formed quite rapidly after the addition of hydroxyethyl cellulose.
Example 11
Cuprous Oxo-Hydroxide, Cu + 10 OH
All solutions/suspensions were bubbled with nitrogen before and throughout the synthesis to achieve low oxygen conditions. A cuprous solution was prepared by adding cuprous chloride to water that had been previously acidified with hydrochloric acid. The final copper concentration was 10 mM and the pH was generally below 2.0 and usually about 1.0. Once all of the cuprous salt dissolved, the pH was raised with a NaOH solution to pH 7.0-9.0, usually 8.0, during which a precipitate, i.e. cuprous oxo-hydroxide, was formed. The material was initially a faint yellow colour and turned blue/green when tested in an atmosphere having 21% oxygen. Finally, this material was incorporated as a nanoparticulate dispersion in a semi-solid matrix.
Example 12
Cuprous Oxo-Hydroxide, Cu + 20 OH
Example 11 was repeated using 20 mM copper instead. An initial pH of about 1.0 was required, to ensure full dissolution of the cuprous salt, prior to commencement of the synthesis.
Example 13
Gluconate-Modified Cuprous Oxo-Hydroxide, Cu + 20 OH-Gluc 100
All solutions/suspensions were bubbled with nitrogen before and throughout the synthesis to achieve low oxygen conditions. A cuprous solution was prepared by adding cuprous chloride to water that had been previously acidified with hydrochloric acid and agitated until all of the cuprous salt dissolved. This solution was then added to another solution containing sodium gluconate. The solution obtained from mixing the two solutions contained 20 mM copper and 100 mM gluconate, and its pH was about 1.0-2.0. The pH was then raised with a NaOH solution to pH 7.0-9.0, usually 8.0, during which a blue/green precipitate, i.e. gluconate modified cuprous oxo-hydroxide, was formed. Finally, this suspension was used directly as a sensor, recovered through filtration for other oxygen sensing methods, or, in some preferred embodiments, dispersed in a semi-solid matrix.
Example 14
Nanoparticulate Cysteine-Modified Cuprous Oxo-Hydroxide, Cu + 20 OH-Cys 20
All solutions/suspensions were bubbled with nitrogen before and throughout the synthesis to achieve low oxygen conditions. A cuprous solution was prepared by adding cuprous chloride to water that had been previously acidified with hydrochloric acid and agitated until all of the cuprous salt dissolved. This solution was then added to another solution containing cysteine. The solution obtained from mixing the two solutions contained 20 mM copper and 20 mM cysteine, and its pH was about 1.0. The pH was then raised with a 5 M NaOH solution to pH 7.0-9.0, usually 8.0, during which a brown nanoparticulate suspension, i.e. cuprous oxo-hydroxide nanoparticles, was formed that turned black upon oxidation/sensing. Finally, this suspension was used directly as a sensor, recovered through filtration for other oxygen sensing methods, or, preferably, incorporated as a nanoparticulate dispersion in a semi-solid matrix.
Example 15
Cuprous Oxo-Hydroxide Dispersed in a Gelatin Semi-Solid Matrix
The following process was carried out under a nitrogen atmosphere. First, cuprous oxo-hydroxide was prepared as described in Example 11, 12 or 13. Next, beef gelatine (15% w/w) was added to this suspension while stirring. Then, the mixture was heated to 40° C. to dissolve the gelatine. Once the gelatine was fully dissolved, the pH was re-adjusted back to its original level with a NaOH solution. Finally, a semi-solid matrix that immobilised and dispersed the cuprous oxo-hydroxide into nanoparticles, was formed by cooling this suspension to room temperature.
Example 16
Nanoparticulate Cuprous Oxo-Hydroxide Immobilised in a Gelatin Semi-Solid Matrix
The following process was carried out under a nitrogen atmosphere. A nanoparticulate cuprous oxo-hydroxide was prepared as described in Example 14. Next, this suspension was heated to 40° C. Then, beef gelatine (15% w/w) was added to this suspension while stirring. Once the gelatine was fully dissolved, the pH was re-adjusted back to its original level with a NaOH solution. Finally, a semi-solid matrix that immobilised the cuprous oxo-hydroxide nanoparticles was formed by cooling this suspension to room temperature.
Example 17
Comparison of the Sensitivity Ferrous Oxo-Hydroxide Materials Immobilised in a Gelatin Semi-Solid Matrix: Fe 2+ 40 OH and Fe 2+ 40 OH-Succ 200
Fe 2+ 40 OH and Fe 2+ 40 OH-Succ 200 where produced at pH 8.0 and immobilised in gelatin as described in Example 8. Prior to cooling down, 500 microliters of each suspension was dispensed under a flow of nitrogen into top-opened cylindrical moulds (1.35 cm inner radius). The sensing materials remained in the top-opened moulds for the duration of the sensing experiment and initially where kept in an oxygen free chamber (<100 ppm O 2 ). Next concentration of oxygen was raised to 0.5% to allow oxidation. After 2 h 30 min under 0.5% O 2 , the Fe 2+ 40 OH-Succ 200 material changed from green to orange (Fe 2+ to Fe 3+ oxidation) while Fe 2+ 40 OH remained green, showing that the incorporation of succinate increased sensitivity in relation to Fe 2+ 40 OH.
In general, it should be noted that different sizes and shapes of sensors impact on sensing time. For example, sensing materials produced in shallower moulds, than those described herein, will change colour faster, since oxygen will permeate shorter distances through the semi-solid matrix before reaching the entirety of the sensing material.
Example 18
Comparison of the Sensitivity Ferrous Oxo-Hydroxide Materials Immobilised in a Gelatin Semi-Solid Matrix: Fe 2+ 40 OH and Fe 2+ 40 OH-T 200
Fe 2+ 40 OH and Fe 2+ 40 OH-T 200 where produced at pH 8.0 and immobilised in gelatin as described in Examples 8 and 9. Prior to cooling down, 500 microliters of each suspension was dispensed under a flow of nitrogen into top-opened cylindrical moulds (1.35 cm inner radius). The sensing materials remained in the top-opened moulds for the duration of the sensing experiment and initially where kept in an oxygen free chamber (<100 ppm O 2 ). Next concentration of oxygen was raised to atmospheric level (21%) to allow oxidation. After 40 min under 21% O 2 , a change from green to orange (Fe 2+ to Fe 3+ oxidation) was already visible in the Fe 2+ 40 OH material while Fe 2+ 40 OH-T 200 remained green.
Nanosensors: Proof-of-Concept
Testing of Oxygen Sensors
In the examples that follow, the oxygen sensors were tested directly in suspension or trapped in a gelatine matrix. The sensors were then either exposed to atmospheric oxygen or kept in an oxygen-free environment (i.e. nitrogen). A gelatine matrix was use to stabilise some of the sensors in a ‘solid form’ for proof-of-principle purposes but in commercial embodiments, other materials may be used instead or in addition to gelatine.
Sensors in Suspension
Fe 2+ 40 OH-T 200 is a nanoparticulate ferrous oxo-hydroxide modified with tartaric acid, which is dark green, but upon exposure to oxygen, the solution changes to orange/brown. This is due to the oxidation of ferrous iron (Fe 2+ ) as ferrous oxo-hydroxide to ferric iron (Fe 3+ ). Similar results were obtained with a different ratio of iron to tartaric acid (Fe 2+ 40 OH-T 120 but the colour change was found to occur more rapidly.
Succinate and citric acid were also used as ligands and the resulting ferrous oxo-hydroxides showed similar behaviour. The colour of Fe 2+ 40 OH-T 200 Succ 200 changed from green to orange/brown upon oxidation. The nanoparticulate suspension is lighter in colour and more precipitate is formed upon oxidation than with Fe 2+ 40 OH-T 200 , but the colour change was still clearly seen.
Sensors in a Solid Matrix
Unmodified (i.e. with no added ligands) and tartrate-doped ferrous oxo-hydroxides were immobilised and nano-dispersed in a gelatine matrix as proof of principle. Advantageously, the change of the colour in the solid matrix was even more defined than the colour change in solution. Without wishing to be bound by any particular theory, the present inventors believe that the alteration in colour observed in these experiments using a matrix material such as gelatine may be due to the incorporation of pendant groups from the matrix into the ferrous oxo-hydroxide material, and indicates that these pendant groups present in the matrix material may, given the right synthetic conditions, alter the physicochemical properties of metal ion oxo-hydroxide materials in a similar fashion to free ligands, such as tartrate.
Overall, these results show that we can apply these oxygen sensors to packaging by incorporating them in a matrix such as gelatine and suggest that other ingredients that can form a gel or solid matrix, such as starch or cellulose, can be used. Also, this work showed that different sensitivity can be obtained by producing sensors at different pH's. The use of hydrated matrices also permits other components to be added to the sensors such as other redox sensitive materials, including M containing materials, minerals, compounds or complexes.
Oxygen Indicator in Powder Form
We have investigated the use of dry powders of unmodified and tartrate-doped ferrous oxo-hydroxides as sensors, as dry powders may be preferred for some applications, such as surface coating. The unmodified ferrous oxo-hydroxide powder was originally green, but slight oxidation during the drying process altered it to brownish green. Nevertheless, subsequent exposure to oxygen resulted in further colour change showing that the dry powder, if dried in an oxygen free environment, can be used as a sensor. The tartaric-doped ferrous oxo-hydroxide powder showed a more subtle, and slower, colour change compared to the unmodified ferrous oxo-hydroxide indicating that the sensitivity of sensors based in dry powders may be tailored by ligand modification.
Reactivation of Oxidized Indicators
The packaging process may result in a partial oxidation of the sensor due to unintended exposure to oxygen. We have found evidence that it is possible to reactivate the sensors of the present invention by exposing them to high temperatures (>80° C.) We have also found that this reactivation process is significantly more efficient if in the presence of reducing sugars, such as glucose or fructose.
Copper-Based Sensor
Copper is a transition metal which also forms oxo-hydroxides at high pH and that changes colour when oxidised (cuprous [Cu + ] to cupric [Cu 2+ ]). The colour change of unmodified cuprous oxo-hydroxide in a gelatine matrix was originally very light (Cu + 10 OH) to dark yellow (Cu + 20 OH) to blue greenish (Cu 2+ ) in the presence of oxygen. Cu + 10 OH appeared transparent but in fact was a very faint yellow.
Tailoring of Sensitivity Via Incorporation of Ligands
The incorporation of ligands into the metal ion oxo-hydroxide materials can be used to either increase sensitivity (e.g. Fe 2+ 40 OH-Succ 200 >Fe 2+ 40 OH sensitivity) or to decrease it (Fe 2+ 40 OH-T 200 sensitivity<Fe 2+ 40 OH sensitivity). Without wishing to be bound by a particular theory, the present inventors believe that increased sensitivity appears is achieved by incorporating ligands with low affinity for the metal ion, while the incorporation of higher affinity ligands seems to stabilise the materials at low valence states, thereby decreasing their sensitivity for oxygen.
All documents mentioned in this specification are incorporated herein by reference in their entirety.
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Oxygen sensors and their uses are disclosed, and more particularly to oxygen sensors for use in product packaging for storing an article in a packaging envelope under modified atmosphere conditions wherein the oxygen sensors comprise solid oxo-hydroxy metal ion materials, optionally modified with one or more ligands and/or optionally having polymeric structures. The sensors may be present in a hydrated, oxygen permeable matrix, for example formed from a material, such as gelatine. The sensors are useful in many technical fields, and find particular application in the field of food packaging as they are safely disposable (e.g. are environmentally friendly), cheap to manufacture, and provide detectable changes in the presence of oxygen that are easy to read.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates generally to computer hard drives and more specifically to the interaction of the hard disk with the read/write head.
[0003] 2. Description of Related Art
[0004] Under normal operating conditions, the read/write head of a hard drive does not come into physical contact with the hard disk, but instead rides an air cushion just above the surface of the disk. However, failures can occur, wherein the head come into contact with the disk, resulting in damage to the disk and/or interference with the reading and writing of data. This event is referred to as a head crash or Head-to-Disk Interference (HDI) event. When the read/write head comes in contact with the disk, it can cause extensive loss of data because the magnetic coating on the disk is removed or otherwise made unreadable.
[0005] The magnetic debris resulting from head/disk contact is circulated within the head/disk enclosure until it is deposited on an internal drive filter element. If it were possible to detect the beginning of a head crash event early enough it would be possible to mitigate the loss of data before it became catastrophic.
[0006] Therefore, it would be desirable to have a method for detecting the beginning of a HDI event and minimizing its effects.
SUMMARY OF THE INVENTION
[0007] The present invention provides a method for detecting head-to-disk interference events in a disk drive. The invention comprises coupling a transducer to an air filter in the disk drive, wherein the transducer detects changes in magnetic readings due to debris produced by physical contact between a read/write head and a magnetic storage medium (head crash). The is monitored during disk drive operations and comparing magnetic readings from the transducer with defined parameters. If the transducer readings exceed the defined parameters, the spindle motor of the disk drive is shut off, thus stopping the rotation of the disk and minimizing data loss and damage due to the head crash.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0009] [0009]FIG. 1 depicts a pictorial representation of a data processing system in which the present invention may be implemented;
[0010] [0010]FIG. 2 depicts a block diagram of a data processing system in which the present invention may be implemented;
[0011] [0011]FIG. 3, a pictorial diagram of a hard drive is depicted in which the present invention may be implemented;
[0012] [0012]FIG. 4 depicts a block diagram of a hard drive in accordance with the present invention;
[0013] [0013]FIG. 5A depicts a pictorial diagram illustrating the position of a read/write head relative to a hard disk during normal function;
[0014] [0014]FIG. 5B depicts a pictorial diagram illustrating a head crash;
[0015] [0015]FIG. 6 depicts a flowchart illustrating the hard drive power-on sequence in accordance with the present invention;
[0016] [0016]FIG. 7 depicts a flowchart illustrating drive operation and head crash detection in accordance with the present invention; and
[0017] [0017]FIG. 8 depicts a flowchart illustrating the recovery algorithm in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] With reference now to the figures and in particular with reference to FIG. 1, a pictorial representation of a data processing system in which the present invention may be implemented is depicted in accordance with a preferred embodiment of the present invention. A computer 100 is depicted which includes a system unit 110 , a video display terminal 102 , a keyboard 104 , storage devices 108 , which may include floppy drives and other types of permanent and removable storage media, and mouse 106 . Additional input devices may be included with personal computer 100 , such as, for example, a joystick, touchpad, touch screen, trackball, microphone, and the like. Computer 100 can be implemented using any suitable computer, such as an IBM RS/6000 computer or IntelliStation computer, which are products of International Business Machines Corporation, located in Armonk, N.Y. Although the depicted representation shows a computer, other embodiments of the present invention may be implemented in other types of data processing systems, such as a network computer. Computer 100 also preferably includes a graphical user interface that may be implemented by means of systems software residing in computer readable media in operation within computer 100 .
[0019] With reference now to FIG. 2, a block diagram of a data processing system is shown in which the present invention may be implemented. Data processing system 200 is an example of a computer, such as computer 100 in FIG. 1, in which code or instructions implementing the processes of the present invention may be located. Data processing system 200 employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Accelerated Graphics Port (AGP) and Industry Standard Architecture (ISA) may be used. Processor 202 and main memory 204 are connected to PCI local bus 206 through PCI bridge 208 . PCI bridge 208 also may include an integrated memory controller and cache memory for processor 202 . Additional connections to PCI local bus 206 may be made through direct component interconnection or through add-in boards. In the depicted example, local area network (LAN) adapter 210 , small computer system interface SCSI host bus adapter 212 , and expansion bus interface 214 are connected to PCI local bus 206 by direct component connection. In contrast, audio adapter 216 , graphics adapter 218 , and audio/video adapter 219 are connected to PCI local bus 206 by add-in boards inserted into expansion slots. Expansion bus interface 214 provides a connection for a keyboard and mouse adapter 220 , modem 222 , and additional memory 224 . SCSI host bus adapter 212 provides a connection for hard disk drive 226 , tape drive 228 , and CD-ROM drive 230 . Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors.
[0020] An operating system runs on processor 202 and is used to coordinate and provide control of various components within data processing system 200 in FIG. 2. The operating system may be a commercially available operating system such as Windows 2000, which is available from Microsoft Corporation. An object oriented programming system such as Java may run in conjunction with the operating system and provides calls to the operating system from Java programs or applications executing on data processing system 200 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented programming system, and applications or programs are located on storage devices, such as hard disk drive 226 , and may be loaded into main memory 204 for execution by processor 202 .
[0021] Those of ordinary skill in the art will appreciate that the hardware in FIG. 2 may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash ROM (or equivalent nonvolatile memory) or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in FIG. 2. Also, the processes of the present invention may be applied to a multiprocessor data processing system.
[0022] For example, data processing system 200 , if optionally configured as a network computer, may not include SCSI host bus adapter 212 , hard disk drive 226 , tape drive 228 , and CD-ROM 230 , as noted by dotted line 232 in FIG. 2 denoting optional inclusion. In that case, the computer, to be properly called a client computer, must include some type of network communication interface, such as LAN adapter 210 , modem 222 , or the like. As another example, data processing system 200 may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system 200 comprises some type of network communication interface. As a further example, data processing system 200 may be a personal digital assistant (PDA), which is configured with ROM and/or flash ROM to provide non-volatile memory for storing operating system files and/or user-generated data.
[0023] The depicted example in FIG. 2 and above-described examples are not meant to imply architectural limitations. For example, data processing system 200 also may be a notebook computer or hand held computer in addition to taking the form of a PDA. Data processing system 200 also may be a kiosk or a Web appliance.
[0024] The processes of the present invention are performed by processor 202 using computer implemented instructions, which may be located in a memory such as, for example, main memory 204 , memory 224 , or in one or more peripheral devices 226 - 230 .
[0025] Referring to FIG. 3, a pictorial diagram of a hard drive is depicted in which the present invention may be implemented. The head-disk assembly (HDA) 300 contains a hard disk 301 , a read/write head 302 , and the actuator arm 303 , which controls the movement of the head 302 over the disk 301 .
[0026] The hard disk 301 accommodates data in the form of tiny magnetic transitions. A magnetic coating (data medium) is deposited on the disk 301 , which is made of aluminum or glass. A thin diamond like carbon (DLC) layer is also deposited on disk 301 to protect the magnetic medium against mechanical damage. Finally, a thin lubricant film is applied to the disk surface to provide wear and corrosion resistance. Data is recorded on disk 301 in sectors, identified by their Logical Block Addresses (LBA's) which are arranged in a sequential manner around each track. Usually LBA 0 is located at head 0 , track 0 , sector 0 . The LBA sequentially increases from there. Current disk drives use an interleave factor or 1:1. The rotation of disk 301 is controlled by spindle 305 , which is stabilized by a feedback control circuit to maintain a constant speed, ensuring more accurate data recording and retrieval.
[0027] The read/write head 302 writes data onto disk 301 as tiny magnetic transitions, or detects these magnetic transitions as data bits. Note that various data encoding schemes are used to optimize the ability of the read electronics to accurately reproduce the information written on the disk. The head 302 is moved over disk 301 by actuator arm 303 , which rotates about actuator shaft 304 . The actuator arm 303 allows the head to be positioned above the correct disk sector(s) in order to read or write data. When the disk drive 300 is off, the head 302 rests on a load/unload ramp 308 .
[0028] In the present example, the movement of actuator arm 303 is controlled by “voice coil” motor 306 . Similar to the voice coil of a speaker, the movement of the voice coil motor 306 is determined by the amount and direction of current moving through a coil positioned in a uniform DC magnetic field.
[0029] HDA 300 also has an air recirculation filter 307 , which filters the air already in the HDA case. There is a separate “make up filter” whose purpose is to provide an air circulation path to equalize the air pressure between the inside of the drive and the ambient environment. The purpose of the recirculation filter is to remove microscopic wear debris created during the operation of the moving/rotating elements, as well as HDI events between the head 302 and disk 301 . The rotating disk 301 generates air circulation which moves the microscopic contamination to the recirculation air filter 307 , which removes this debris.
[0030] Referring to FIG. 4, a block diagram of a hard drive is depicted in accordance with the present invention. The host interface chip 401 provides the connection between the hard drive controller and the computer using the hard drive. Read/write commands and command data for the controller are exchanged by means of the interface 401 . The microprocessor 402 controls the host interface 401 and the controller-internal logic elements. For this purpose, a machine program is stored in the microcode of the ROM (or EEPROM) 404 used by the microprocessor 402 . The cache 403 holds the data to be written into or read from a sector of the hard disk.
[0031] Read and write data are communicated to the read/write head via the read/write channel 405 and preamplifier 406 , which boosts the signal to the hardware. The microprocessor controls the rotation of the hard disk by means of the spindle motor control 409 , and the motion of the actuator arm is controlled by means of the servo control 408 , which drives the voice coil motor described in FIG. 3.
[0032] The microprocessor 402 also monitors the drive recirculation filter 407 , which has an imbedded transducer to measure changes in conductance, capacitance or inductance as disk debris accumulates on the filter 407 . This approach takes advantage of the fact that the debris generated by a head crash is a conductive magnetic material. The sensor can be calibrated in the factory during the drive manufacturing burn-in process.
[0033] Referring to FIG. 5A, a pictorial diagram illustrates the position of a read/write head relative to a hard disk during normal function. In order to generate and detect small magnetic transitions for high density data storage, it is necessary for the read/write head 501 to be as close as possible above the hard disk 502 . When the hard drive is off, the head 501 rests off the disk 502 , on a ramp located at the outer diameter, e.g., ramp 308 in FIG. 3. When the hard drive is turned on and the spindle motor begins rotating the hard disk 502 , an air stream is generated which provides a microscopic air bearing upon which the head 501 flies above the disk 502 . When the disk 502 reaches an appropriate angular velocity, the drive servo moves the head 501 from the ramp to the disk 502 , at which time the air bearing is established between the head 501 and disk 502 .
[0034] Note that other disk drive technology exists in which the heads are parked in a landing zone that is physically located at the inner diameter of the drive when the disks are not rotating.
[0035] [0035]FIG. 5B depicts a pictorial diagram illustrating a head crash. Contact between the head 501 and disk 502 (head crash) can be caused by several factors including misalignment and particulate contamination. A head crash which occurs while the disk 502 is rotating at high speeds will cause the head 501 to scrape off and damage the magnetic data medium and protective DLC coating, which results not only in loss of data and damage to the head 501 , but also creates additional particulate contamination which can lead to additional head crashes.
[0036] It should be pointed out that the example disk drive described above, has only one disk and one read/write head. This example is used for the sake of simplicity. However, many modern disk drive comprise several disks stacked on top of each other with small spaces in between the disks to accommodate multiple heads which are mounted on a single actuator arm.
[0037] The present invention provides a method for detecting the occurrence of a HDI and offers algorithms that can be used to mitigate the effect of the HDI to minimize data loss. The early detection of a head crash is accomplished by means of the transducer imbedded in the drive filter unit described above.
[0038] Referring to FIG. 6, a flowchart illustrating the hard drive power-on sequence is depicted in accordance with the present invention. After power is applied to the hard drive (step 601 ), the microprocessor samples the transducer as part of the power on diagnostics (step 602 ). The drive is then spun up by the spindle motor (step 603 ). After the drive is up to speed, the microprocessor periodically samples the transducer in order to establish a baseline measurement (step 604 ). Once this baseline is established, the system moves over to the drive operation process (step 605 ).
[0039] Referring to FIG. 7, a flowchart illustrating drive operation and head crash detection is depicted in accordance with the present invention. During the recording and reading of data, the hard drive accesses the read/write control (step 701 ). As reading and writing occurs, the microprocessor continues to periodically sample the transducer (step 702 ) and determines if the transducer measurements have changed (step 703 ). The algorithm used by the microprocessor monitors the chosen property (resistance, capacitance, inductance) and looks for a sudden increasing change in this property. If the readings have not changed, the drive operations continue as normal. However, if there is a change in the transducer measurements, the microprocessor then determines if this change is significant relative to the baseline established during power-on (step 704 ). If the change is not significant, the drive operation continues as normal. If the change is significant, the condition status and sense data is returned to command (step 705 ) and the recovery algorithm is initiated (step 706 ).
[0040] Referring to FIG. 8, a flowchart illustrating the recovery algorithm is depicted in accordance with the present invention. When the recovery algorithm is initiated, the microcode in the drive unloads the head from the disk in order to allow time for the debris to be removed from the drive by the filter (step 801 ). During this idle period the disk drive microcode analyzes its internal error logs to determine the extent of the damage by mapping the recent occurrences of unrecoverable media errors and/or servo errors due to lack of servo information (step 802 ).
[0041] After a period of time, which is based upon the time it takes to filter all of the air inside the HDA, the head is loaded back onto the media and swept across the disk quickly to assist in cleaning further debris from the disk surface (step 803 ). The head is again unloaded after being swept across the disk in order to minimize further disk damage (step 804 ).
[0042] The drive responds to commands received from the host system with “Not Ready” Sense Key followed by a Sense Code indicating that the drive needs to be immediately backed up because it is failing (step 805 ), and the spindle motor is shut off (step 806 ).
[0043] After receiving the unrecoverable-media-error data from the drive, the host system issues a Start Unit Command when it is ready to begin the back up process, and performs sequential read operations to recover as much data from the drive as possible (step 807 ). The drive does not allow the head to access zones where there were multiple hard errors.
[0044] Without the present invention, when a HDI event occurs, the drive continues to attempt error recovery procedures that aggravate the failure to the point where it is very difficult, if not impossible, to determine the cause of the failure. With the present invention, the drive is able to detect the beginning of the HDI and initiate procedures to mitigate the problem, making it easier to determine the cause of the HDI.
[0045] It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such as a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communications links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The computer readable media may take the form of coded formats that are decoded for actual use in a particular data processing system.
[0046] The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
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A method for detecting head-to-disk interference events in a disk drive is provided. The invention comprises coupling a transducer to an air filter in the disk drive, wherein the transducer detects changes in magnetic readings due to debris produced by physical contact between a read/write head and a magnetic storage medium (head crash). The is monitored during disk drive operations and comparing magnetic readings from the transducer with defined parameters. If the transducer readings exceed the defined parameters, the spindle motor of the disk drive is shut off, thus stopping the rotation of the disk and minimizing data loss and damage due to the head crash.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is the U.S. National Stage of International Application No. PCT/EP20091007300, filed Oct. 7, 2009, which designated the United States and has been published as International Publication No. WO 2010/040563 and which claims the priority of German Patent Application, Serial No. 10 2008 050 223.5, filed Oct. 7, 2008, pursuant to 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTION
Device for cleaning fluid media containing particulate matter, particularly from livestock husbandry, through ozonization in a closed ozonizing container and subsequent separation of the particulate matter portions.
Wastewater from livestock husbandry containing feces, namely liquid manure, is typically collected in storage tanks and after the harvest deployed on farmland as natural fertilizer. As a result, a significant amount of unpleasant odor is generated in the environment.
Such wastewater collection occurs also onboard ships. More particularly, a significant amount of wastewater is produced onboard large seagoing vessels, in particular cruise ships, which cannot and must not simply be discarded overboard. As a result, a commensurately large tank storage space must be provided.
DE 29 20 010 A1 discloses removing contaminants in ground water and surface water with ozone. In this way, wastewater with natural contaminants or contaminants stemming from production processes of the chemical industry is cleaned.
A method for condensing and freezing water vapor from a gas mixture disclosed in DE-OS 1 960 953 is in employed in systems used to precipitate a particular component, for example sulfur dioxide, from a gas mixture, wherein the cold residual gas is used for heat exchange with supplied hot and unprocessed gas, and the gas mixture is supposedly relatively free of water before entering the condenser. It is known from DE-OS 2 025 523 to perform volumetric measurements for monitoring and controlling chemical treatment baths.
The publication “Wasser, Luft und Betrieb” ( Water, Air and Operation ), 19 (1975) No. 4, p. 147-152 discloses the use of ozone for the treatment of water and air. DE-AS 10 62 394 discloses a method and an apparatus for removing odor from air, in particular from industrial waste gases, with ozone, which in essence consists of an inlet tube with a Venturi nozzle. The contaminated air is mixed via the inlet tube with ozone in a mixing device, wherein the ozone is suctioned from an ozinator by a vacuum created at the Venturi nozzle of the inlet tube.
U.S. Pat. No. 4,430,306 discloses an apparatus for recovering oxygen after ozonizing reactions. To this end, O 2 which is not consumed in an ozonizing reaction is supplied to a drying tower where contaminants such as water, organic contaminants and CO 2 are absorbed on zeolites. The cleaned oxygen is returned to the ozinator for increasing the ozone yield.
GB 1 427 614 C1 describes a method and an apparatus capable of cleaning contaminated, in particular foul air by applying ozone. Ozone-saturated moist air and very fine ozone-saturated water droplets are blown into the contaminated gases, wherein the ozone concentration can be continuously measured and regulated.
While all these methods and apparatuses are used for removing noxious odors caused by contaminated wastewater, the contaminated wastewater must be intermediately stored in relatively large tank vessels and the ozone consumption is relatively high. This requires significant storage space which is generally not unlimited, in particular on ships. Moreover, they are not suited to remove the sources from the wastewater at reasonable costs and to keep the required intermediate storage space as small as possible.
It is an object of the invention to provide a device for removing contaminants from liquid media, which minimizes the ozone consumption and which is capable of cost-effectively removing the suspended particles causing the unpleasant odors.
SUMMARY OF THE INVENTION
This object is attained with a device for cleaning liquid media containing particulate matter, in particular from animal husbandry, wherein the device includes a closed ozonizing container in which the liquid media containing particulate matter is ozonized and the particulate matter fraction is subsequently separated, a vertical hollow-cylindrical fixture arranged in the closed ozonizing container, a rotatable agitator shaft having two ends and being operatively connected to the fixture, agitation means cooperating with the agitator shaft, and ozone feed lines connected to the fixture for introduced ozone into the closed ozonizing container.
The device according to the invention includes a closed ozonizing container, in which vertical hollow-cylindrical fixtures are arranged, the fixtures are operatively connected with a rotatable agitator shaft, with agitation means associated with the agitator shaft, and the fixtures are provided with feed lines through which ozone can be introduced.
An advantageous embodiment of the invention has a closed ozonizing container in which a vertical hollow-cylindrical fixture which is open on both ends is arranged, with a rotatable agitator shaft passing through the fixture and a agitating propeller being associated with both ends of the agitator shaft, wherein the fixture is provided with a ring-shaped line through which the ozone can be introduced into the hollow-cylindrical fixture; the closed ozonizing container is preferably spherical.
The device according to the invention can therefore very effectively neutralize constituents in the wastewater that cause unpleasant odors at low costs.
According to another advantageous embodiment of the invention, a conventional stator is provided in the ozonizing container on the bottom end of the agitator shaft, in which a very fast rotating rotor is arranged as agitation means. The agitator shaft is supported on its top end in a bearing flange and is driven by an electric motor.
With this embodiment, relatively high shearing forces are generated with which particulate matter lumps suspended in the medium to be cleaned can be broken down and the medium can be homogenized.
In the device according to the invention, the ring-shaped line for introducing ozone is arranged in the region of the bottom opening of the hollow-cylindrical fixture. These measures ensure that the wastewater intensively interacts with the ozone and is effectively aerated with the gas.
In another advantageous embodiment of the device according to the invention, the ring-shaped line includes nozzles oriented radially into the fixture. Particularly fine ozone bubbles can be generated with this arrangement. As a result of the increased surface area, the reactive surface of the wastewater also increases which shortens the application time of the ozone and hence also shortens the process.
In a particularly advantageous embodiment of the device according to the invention, the agitator propellers arranged on both ends produce a flow in the fixture. The wastewater is thereby permanently kept in motion, so that larger solid components are unable to settle.
It is also ensured that heavy solid components are kept suspended in the wastewater and are prevented from lumping together and settling, which would remove them from the interaction with the ozone.
In another preferred embodiment of the device according to the invention, a closed material separating container, into which the wastewater that was previously treated with ozone in the ozonizing container can be transferred by pumping, is arranged downstream of the closed container. The wastewater pumped from the closed ozonizing container is centrifuged in the material separating container. The heavier flocculated particulate matter is transported to the outside into catch bags for heavy materials, where they are collected and optionally separated. The remaining and now clean wastewater can be readily disposed of.
According to an embodiment according to the invention, the catch bags for heavy materials have discharge flaps which open downward. The flocculated separated heavy materials can then be removed and intermediately stored without taking up much space. The volume of the contaminants which must be intermediately stored for proper disposal can thereby be significantly reduced.
In another preferred embodiment of the device according to the invention, a conventional material separating device is used for separating the suspended particles from the homogenized ozonized medium. The material separating device essentially includes a horizontal housing with an inlet for the medium to be cleaned, wherein a receiving drum which consists of a cylindrical drum part and a conical drum part is disposed inside the housing; a feed screw which is operatively connected with the interior surface of the conical drum part is arranged in the receiving drum.
BRIEF DESCRIPTION OF THE DRAWING
Exemplary embodiments of the invention will now be described with reference to the appended drawing, which shows in:
FIG. 1 shows a spherical closed ozonizing container with a vertical hollow-cylindrical fixture which is open on both sides, through which a rotatable agitator shaft passes, which has on both ends an associated agitator propeller;
FIG. 2 shows a spherical closed ozonizing container according to FIG. 1 , with a vertical hollow-cylindrical fixture which is open on both sides, with an agitator with a rotor that rapidly rotates in a stator arranged in the fixture;
FIG. 3 shows a spherical closed material separating container, into which the wastewater that was previously treated with the ozone in the spherical closed ozonizing container can be pumped and centrifuged, wherein the flocculated particulate matter is centrifuged outwardly into capture bags and captured;
FIG. 4 shows a material separating container, with one half in form of a truncated cone and the other half in form of a cylinder, into which the wastewater that was previously treated with the ozone in the spherical closed ozonizing container can be pumped and centrifuged, wherein the flocculated particulate matter is centrifuged radially outwardly toward the container wall, where it can settle and be removed with a feed screw.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The cleaning device 10 according to the invention illustrated in FIG. 1 is composed of a preferably spherical ozonizing container 11 . The ozonizing container 11 may be filled with wastewater to be cleaned, for example liquid manure from agricultural operations or wastewater loaded with feces, through an inlet valve 11 a . The ozonizing container 11 is preferably spherical so as to attain an optimal surface-to-volume ratio.
In the installed position, the spherical ozonizing container 11 has at the top a welding neck flange 12 with a manhole 13 . The ozonizing container 11 may be inspected, as necessary, through the manhole 13 .
The manhole 13 may be closed to the outside with a blind flange 14 . An agitator drive 15 , for example an electric motor, is attached on the blind flange 14 . An agitator shaft 16 , which extends in the installed position perpendicular through a hollow-cylindrical fixture 17 in the spherical ozonizing container 11 , can be driven with the agitator drive 15 .
The hollow-cylindrical fixture 17 has in the installed position at the top an upper agitator propeller 18 and in the installed position at the bottom a lower agitator propeller 19 . The agitator propellers 18 and 19 generate in the hollow-cylindrical fixture 17 a flow 20 of the wastewater to be cleaned which extends from the top to the bottom. To support the flow 20 , the hollow-cylindrical fixture 17 has at its top edge a funnel insert 21 .
The hollow-cylindrical fixture 17 has in the installed position at the bottom a ring-shaped line 22 through which ozone can be blown in radially inwardly via nozzles 22 a . The ozone reaches the ring-shaped line 22 from an external ozone generator 24 through an ozone supply line 23 , from where the ozone is blown in against the flow 20 . This causes optimal intermixing between the wastewater to be cleaned and the ozone. Control fittings 26 are provided for withdrawing samples.
The spherical ozonizing container 11 rests on container supports 27 and includes a drain fixture 25 for draining. After ozonization, where the contaminants are neutralized and flocculated as particulate matter, the wastewater to be cleaned can be pumped from the spherical ozonizing container 11 with a siphoning pump 29 through a pump line 28 and transferred to a particle separation device 10 a or 30 a , as illustrated in FIGS. 3 and 4 below.
In the embodiment according to FIG. 2 , a stator 39 is arranged in the ozonizing container 11 on the bottom end of the agitator shaft 16 . A fast rotating rotor 40 is arranged in the stator 39 . The agitator shaft 16 is hereby supported at its top end in a bearing flange 38 and is driven by an agitator drive 15 in form of an electric motor.
The stator 39 has a rotor space which is open towards the bottom; the ozone feed line 23 terminates in the rotor space. The medium to be cleaned, namely wastewater or liquid manure from farming, it is not a homogeneous material and can contain solid lumped-together particulate matter islands of different size which either do not react at all with the ozone or only insufficiently.
The medium to be cleaned is therefore homogenized by the rotor 40 which rapidly rotates in the stator 39 , while simultaneously ozone is introduced through the ozone feed line 23 . The rotor 40 rotates with approximately 250 and 500 RPM, producing shearing forces high enough to dissolve and intermix the particulate matter islands.
The particulate separating device 10 a illustrated in FIG. 3 is essentially comprised of an upright material separating container 30 which is arranged in an upright housing 31 . The material separating container 30 is constructed according to the invention in form of a truncated cone, wherein the greater diameter of the truncated cone is in the installed position at the top. The material separating container 30 is provided with a centrifugal drive 32 and has an inlet valve 33 through which the medium to be cleaned, which arrives from the cleaning device 10 according to FIG. 1 and has already been ozonized, can be introduced.
After filling, the ozonized wastewater is set into a rapid rotary motion by the centrifugal drive 32 . All process steps inside the material separating container 30 can be monitored with an external measuring station 34 .
As a result of the rotation, the flocculated suspended particles are centrifuged radially outward, where they are captured in capture bags 35 and 35 a and collected. The capture bags 35 and 35 a , respectively, are distributed along the entire circumference of the truncated-cone-shaped material separating container 30 . The capture bags 35 are located at the top in the region of the larger diameter and are provided with coarse sieves 36 . The larger, because heavier particulate matter is transported outwardly first and farther during centrifuging, and collected in the upper catch bags 35 arranged in the region of the larger diameter.
The smaller and lighter particulate matter is moved outwardly less far and collected in the catch bags 35 a which are provided underneath in the region of the small diameter. The lower catch bags 35 a are here provided with fine sieves 36 a . The flocculated particulate matter is fractioned due to the truncated-cone-shaped design of the material separating container 30 .
After all particulate matter is removed from the cleaned wastewater, the cleaned wastewater can be disposed of through a drain valve 33 a and, for example, returned again to the cleaning flow loop.
The cleaned wastewater can also be transported to an additional water treatment system where it is sufficiently cleaned and disinfected so that it can be used again, for example on a ship, as process water and/or drinking water.
The particulate matter captured in the capture bags 35 and 35 a may be discharged, for example, into a storage space 37 provided in the housing 31 and intermediately stored until the time of final disposal. To facilitate emptying the catch bags 35 and 35 a , the coarse sieves 36 and the fine sieves 36 a are constructed as discharge flaps and can be opened discontinuously. The collected solids can be transported to an unillustrated incinerator for disposal.
The conventional material separating device 30 a illustrated in FIG. 4 is essentially constructed of a horizontal a housing 31 a with an inlet valve 42 for the medium to be cleaned. A receiving drum 46 which is rotatably supported on a container bearing 27 is disposed in the horizontal housing 31 a . The receiving drum 46 is constructed of a cylindrical drum part 43 and a conical drum part 44 .
An inlet valve 42 is arranged in the region of the cylindrical drum part 43 . The cylindrical drum part transitions into the conical drum part 44 as a single piece.
A feed screw 45 , which is operatively connected with the interior surface of the conical drum part 44 , is arranged inside the receiving drum 46 . The receiving drum 46 can be set into a rapid rotation by a drum drive 47 , for example by an unillustrated electric motor. The rotation speed which is important for the material separation can be varied with a control drive 48 .
After the material has been separated, the fluid can be drained through a drain valve 49 . The relatively dry, solid suspended particles that were separated from the medium to be cleaned can be removed through a solid matter discharge port 50 .
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The invention relates to a device for cleaning fluid media containing particulate matter, particularly from livestock husbandry, by means of ozonization in a closed ozonization container ( 11 ) and subsequent separation of the particulate matter portions. A vertically extending hollow cylindrical fixture ( 17 ) is disposed in the closed ozonization container ( 11 ). The fixture ( 17 ) is operatively connected to a rotating agitator shaft ( 16 ), wherein agitation means ( 18, 19 ) are associated with the agitator shaft ( 16 ), and the fixture ( 17 ) is equipped with supply lines ( 22, 23 ) by means of which ozone can be fed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application is a national stage filing under 35 U.S.C. 371 of International Application No. PCT/EP2007/056563, filed on Jun. 29, 2007, which claims the benefit of priority to United Kingdom Patent Application No. 0613925.7, filed on Jul. 13, 2006. Priority to each application is hereby claimed.
FIELD OF THE INVENTION
The present invention relates improvements relating to pharmaceutical compositions. In particular it relates to pharmaceutically active compositions and precursors therefor which contain a so-called “statin”
BACKGROUND OF THE INVENTION
Statins are believed to reduce serum LDL cholesterol levels by inhibition of 3-hydroxy-3-methylglutaryl CoenzymeA reductase (HMG-CoA Reductase). Several statins are known, including Atorvastatin, Cerivastatin, Fluvastatin, Lovastatin, Mevastatin, Pitavastatin, Pravavastatin, Rosuvastatin and Simvastatin.
Statins have been proposed for use in the treatment of coronary heart disease, myocardial infarction, stroke and peripheral artery disease and the statins appear to have favorable effect in the treatment of inflammation, dementia neoplastic conditions, nuclear cataracts and pulmonary hypertension.
Many statins exhibit low water solubility and are practically insoluble in water. This hinders their effective use.
Our co-pending international patent application PCT/GB03/03226 describes the formation of solid, porous beads comprising a three dimensional open-cell lattice of a water-soluble polymeric material. These are typically ‘templated’ materials formed by the removal of both water and a non-aqueous dispersed phase from a high internal phase emulsion (HIPE) which has a polymer dissolved in the aqueous phase. The beads are formed by dropping the HIPE emulsion into a low temperature fluid such as liquid nitrogen, then freeze-drying the particles formed to remove the bulk of the aqueous phase and the dispersed phase. This leaves behind the polymer in the form of a ‘skeletal’ structure. The beads dissolve rapidly in water and have the remarkable property that a water-insoluble component dispersed in the dispersed phase of the emulsion prior to freezing and drying can also be dispersed in water on solution of the polymer skeleton of the beads.
WO 2005/011636 discloses a non-emulsion based spray drying process for forming ‘solid amorphous dispersions’ of drugs in polymers. In this method a polymer and a low-solubility drug are dissolved in a solvent and spray-dried to form dispersions in which the drug is mostly present in an amorphous form rather than in a crystalline form.
Our co-pending applications GB 0501835 and GB 0613925 (filed 13 Jul. 2006) describe how materials which will form a nano-dispersion in water can be prepared, preferably by a spray-drying process. In the first of these applications the water insoluble materials is dissolved in the solvent-phase of an emulsion. In the second, the water-insoluble materials are dissolved in a mixed solvent system and co-exist in the same phase as a water-soluble structuring agent. In both cases the liquid is dried above ambient temperature (above 20 Celsius), such as by spray drying, to produce particles of the structuring agent, as a carrier, with the water-insoluble materials dispersed therein. When these particles are placed in water they dissolve, forming a nano-dispersion of the water-insoluble material with particles typically below 300 nm. This scale is similar to that of virus particles, and the water-insoluble material behaves as though it were in solution.
WO 2003/103640 (Elan Pharma International Ltd) discloses nanoparticulate forms of statins (particularly Lovastatin or Simvastatin). Particle sizes are disclosed from 2000 nm down to 50 nm. Methods for the production of these nanoparticles include grinding, milling, homogenisation, and precipitation methods.
In the present application the term ‘ambient temperature’ means 20 degrees Celsius and all percentages are percentages by weight unless otherwise specified.
BRIEF DESCRIPTION OF THE INVENTION
We have now determined that both the emulsion-based and the single-phase method can be used to produce a water-soluble, nano-disperse form of a statin.
Accordingly, the present invention provides a process for the production of a composition comprising a water-insoluble statin which comprises the steps of:
a) providing a mixture comprising:
i) a water-insoluble statin ii) a water soluble carrier, iii) a solvent for each of the statin and the carrier, and
b) spray-drying the mixture to remove the or each solvent and obtain a substantially solvent-free nano-dispersion of the statin in the carrier.
The preferred method of particle sizing for the dispersed products of the present invention employs a dynamic light scattering instrument (Nano S, manufactured by Malvern Instruments UK). Specifically, the Malvern Instruments Nano S uses a red (633 nm) 4 mW Helium-Neon laser to illuminate a standard optical quality UV curvette containing a suspension of material. The particle sizes quoted in this application are those obtained with that apparatus using the standard protocol. Particle sizes in solid products are the particle sizes inferred from the measurement of the particle size obtained by solution of the solid in water and measurement of the particle size.
Preferably, the peak diameter of the water-insoluble statin is below 800 nm. More preferably the peak diameter of the water-insoluble statin is below 500 nm. In a particularly preferred embodiment of the invention the peak diameter of the water-insoluble statin is below 200 nm.
It is believed that reduction of the particle size in the eventual nano-dispersion has significant advantages in improving the availability of the otherwise water-insoluble material. This is believed to be particularly advantageous where an improved bio-availability is sought, or, in similar applications where high local concentrations of the material are to be avoided. Moreover it is believed that nano-dispersions with a small particle size are more stable than those with a larger particle size.
In the context of the present invention, “water insoluble” as applied to the statin means that its solubility in water is less than 10 g/L. Preferably, the water insoluble statin has solubility in water at ambient temperature (20 Celsius) less than 5 g/L preferably of less than 1 g/L, especially preferably less than 150 mg/L, even more preferably less than 100 mg/L. This solubility level provides the intended interpretation of what is meant by water-insoluble in the present specification.
Preferred water-insoluble statins include Atorvastatin, Cerivastatin, Fluvastatin, Lovastatin, Mevastatin, Pitavastatin, Pravavastatin, Rosuvastatin, Simvastatin and water insoluble derivatives thereof. For example, the range of solubilities of lovastatin, mevastatin and simvastatin lie between 0.0013-0.0015 mg/ml.
Preferred carrier materials are selected from the group consisting of water-soluble inorganic materials, surfactants, polymers and mixtures thereof.
A further aspect of the present invention provides a process for preparing a statin composition comprising a water-insoluble statin and a water-soluble carrier, which comprises the steps of:
a) forming an emulsion comprising:
i) a solution of the statin in a water-immiscible solvent for the same, and ii) an aqueous solution of the carrier, and,
b) drying the emulsion to remove water and the water-immiscible solvent to obtain a substantially solvent-free nano-dispersion of the statin in the carrier
For convenience, this class of method is referred to herein as the “emulsion” method.
A further aspect of the present invention provides a process for preparing a statin composition comprising a water insoluble statin and a water-soluble carrier which comprises the steps of:
a) providing a single phase mixture comprising:
i) at least one non-aqueous solvent ii) optionally, water iii) a water-soluble carrier material soluble in the mixture of (i) and (ii) and iv) a water-insoluble statin which is soluble in the mixture of (i) and (ii), and,
b) drying the solution to remove water and the water miscible solvent to obtain a substantially solvent-free nano-dispersion of the statin in the carrier.
For convenience, this class of method is referred to herein as the “single-phase” method.
In the context of the present invention substantially solvent free means that the free solvent content of the product is less than 15% wt, preferably below 10% wt, more preferably below 5% wt and most preferably below 2% wt.
In the context of the present invention it is essential that both the carrier material and the statin are essentially fully dissolved in their respective solvents prior to the drying step. It is not within the ambit of the present specification to teach the drying of slurries. For the avoidance of any doubt, it is therefore the case that the solids content of the emulsion or the mixture is such that over 90% wt, preferably over 95%, and more preferably over 98% of the soluble materials present is in solution prior to the drying step.
In relation to the methods mentioned above, the preferred statin and the preferred carrier materials are as described above and as elaborated on in further detail below. Similarly the preferred physical characteristics of the material are as described above.
The ‘single phase’ method where both the statin and the carrier material are dissolved in a phase comprising at least one other non-aqueous solvent (and optional water) is preferred. This is believed to be more efficacious in obtaining a smaller particle size for the nano-disperse statin. Preferably, the drying step simultaneously removes both the water and other solvents and, more preferably, drying is accomplished by spray drying at above ambient temperature.
The products obtainable by the process aspects of the present invention are suitable for use in the preparation of medicaments for treatment or prophylaxis of coronary heart disease, myocardial infarction, stroke, peripheral artery, inflammation, dementia, neoplastic conditions, nuclear cataracts and/or pulmonary hypertension.
A further aspect of the present invention provides a method for the preparation of a medicament for use in the treatment or prophylaxis of coronary heart disease, myocardial infarction, stroke, peripheral artery, inflammation, dementia, neoplastic conditions, nuclear cataracts and/or pulmonary hypertension which comprises the step of preparing a composition according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Various preferred features and embodiments of the present invention are described in further detail below.
Statins:
As noted above the preferred water-insoluble anti-parasitic drugs are water-insoluble anti-malarial drugs selected from the group consisting of Atorvastatin, Cerivastatin, Fluvastatin, Lovastatin, Mevastatin, Pitavastatin, Pravavastatin, Rosuvastatin, Simvastatin and derivatives and mixtures thereof. These can be present as the sole pharmaceutically active ingredient in compositions according to the present invention or be together with other drugs to provide a so-called ‘combination therapy’. As an illustrative example, Simvastatin is also available in a combination formulation with Ezetimibe.
Water-Dispersible Product Form:
The present invention provides a method for obtaining a water-dispersible form of an otherwise water-insoluble material. This is prepared by forming a not wholly aqueous intermediate emulsion or solution in which both a water-soluble carrier material and the water insoluble statin are dissolved. On removal of solvents the insoluble statin is left dispersed through the water-soluble carrier material. Suitable carrier materials are described in further detail below.
The structure of the material obtained after the drying step is not well understood. It is believed that the resulting dry materials are not encapsulates, as discrete macroscopic bodies of the water-insoluble materials are not present in the dry product. Neither are the dry materials ‘dry emulsions’ as little or none of the volatile solvent comprising the ‘oil’ phase of the emulsion remains after the drying step. On addition of water to the dry product the emulsion is not reformed, as it would be with a ‘dry emulsion’. It is also believed that the compositions are not so-called solid solutions, as with the present invention the ratios of components present can be varied without loss of the benefits. Also from X-ray and DSC studies, it is believed that the compositions of the invention are not solid solutions, but comprise nano-scale, phase-separated mixtures.
Preferably, the compositions produced after the drying step will comprise the statin and the carrier in a weight ratio of from 1:500 to 1:1 (as statin:carrier), 1:100 to 1:1 being preferred. Typical levels of around 10-30% wt water-insoluble statin and 90-70% wt carrier can be obtained by spray drying.
By the method of the present invention the particle size of the statin materials can be reduced to below 100 nm and may be reduced to around 15 nm. Preferred particle sizes are in the range 40-15 nm.
‘Emulsion’ Preparation Method:
In one preferred method according to the invention the solvent for the water-insoluble statinis not miscible with water. On admixture with water it therefore can form an emulsion.
Preferably, the non-aqueous phase comprises from about 10% to about 95% v/v of the emulsion, more preferably from about 20% to about 68% v/v.
The emulsions are typically prepared under conditions which are well known to those skilled in the art, for example, by using a magnetic stirring bar, a homogeniser, a sonicator or a rotational mechanical stirrer. The emulsions need not be particularly stable, provided that they do not undergo extensive phase separation prior to drying.
Homogenisation using a high-shear mixing device is a particularly preferred way to make an emulsion in which the aqueous phase is the continuous phase. It is believed that this avoidance of coarse emulsion and reduction of the droplet size of the dispersed phase of the emulsion, results in an improved dispersion of the ‘payload’ material in the dry product.
In a preferred method according to the invention a water-continuous emulsion is prepared with an average dispersed-phase droplet size (using the Malvern peak intensity) of between 500 nm and 5000 nm. We have found that an ‘Ultra-Turrux’ T25 type laboratory homogenizer (or equivalent) gives a suitable emulsion when operated for more than a minute at above 10,000 rpm.
There is a directional relation between the emulsion droplet size and the size of the particles of the ‘payload’ material, which can be detected after dispersion of the materials of the invention in aqueous solution. We have determined that an increase in the speed of homogenization for precursor emulsions can decrease final particle size after re-dissolution.
It is believed that the re-dissolved particle size can be reduced by nearly one half when the homogenization speed increased from 13,500 rpm to 21,500 rpm. The homogenization time is also believed to play a role in controlling re-dissolved particle size. The particle size again decreases with increase in the homogenization time, and the particle size distribution become broader at the same time.
Sonication is also a particularly preferred way of reducing the droplet size for emulsion systems. We have found that a Hert Systems Sonicator XL operated at level 10 for two minutes is suitable.
It is believed that ratios of components which decrease the relative concentration of the anti-parasitic to the solvents and/or the carrier give a smaller particle size.
‘Single Phase’ Preparation Method:
In an alternative method according to the present invention both the carrier and the statin are soluble in a non-aqueous solvent or a mixture of such a solvent with water. Both here and elsewhere in the specification the non-aqueous solvent can be a mixture of non-aqueous solvents.
In this case the feedstock of the drying step can be a single phase material in which both the water-soluble carrier and the water-insoluble statin are dissolved. It is also possible for this feedstock to be an emulsion, provided that both the carrier and the statin are dissolved in the same phase.
The ‘single-phase’ method is generally believed to give a better nano-dispersion with a smaller particle size than the emulsion method.
It is believed that ratios of components which decrease the relative concentration of the statin to the solvents and/or the carrier give a smaller particle size.
Drying:
Spray drying is well known to those versed in the art. In the case of the present invention some care must be taken due to the presence of a volatile non-aqueous solvent in the emulsion being dried. In order to reduce the risk of explosion when a flammable solvent is being used, an inert gas, for example nitrogen, can be employed as the drying medium in a so-called closed spray-drying system. The solvent can be recovered and re-used.
We have found that the ‘Buchi’ B-290 type laboratory spray drying apparatus is suitable.
It is preferable that the drying temperature should be at or above 100 Celsius, preferably above 120 Celsius and most preferably above 140 Celsius. Elevated drying temperatures have been found to give smaller particles in the re-dissolved nano-disperse material.
Carrier Material:
The carrier material is water soluble, which includes the formation of structured aqueous phases as well as true ionic solution of molecularly mono-disperse species. The carrier material preferably comprises an inorganic material, surfactant, a polymer or may be a mixture of two or more of these.
It is envisaged that other non-polymeric, organic, water-soluble materials such as sugars can be used as the carrier. However the carrier materials specifically mentioned herein are preferred.
Suitable carrier materials (referred to herein as ‘water soluble carrier materials’) include preferred water-soluble polymers, preferred water-soluble surfactants and preferred water-soluble inorganic materials.
Preferred Polymeric Carrier Materials:
Examples of suitable water-soluble polymeric carrier materials include:
(a) natural polymers (for example naturally occurring gums such as guar gum, alginate, locust bean gum or a polysaccharide such as dextran; (b) cellulose derivatives for example xanthan gum, xyloglucan, cellulose acetate, methylcellulose, methyl-ethylcellulose, hydroxy-ethylcellulose, hydroxy-ethylmethyl-cellulose, hydroxy-propylcellulose, hydroxy-propylmethylcellulose, hydroxy-propylbutylcellulose, ethylhydroxy-ethylcellulose, carboxy-methylcellulose and its salts (eg the sodium salt—SCMC), or carboxy-methylhydroxyethylcellulose and its salts (for example the sodium salt); (c) homopolymers of or copolymers prepared from two or more monomers selected from: vinyl alcohol, acrylic acid, methacrylic acid, acrylamide, methacrylamide, acrylamide methylpropane sulphonates, aminoalkylacrylates, aminoalkyl-methacrylates, hydroxyethylacrylate, hydroxyethylmethylacrylate, vinyl pyrrolidone, vinyl imidazole, vinyl amines, vinyl pyridine, ethyleneglycol and other alkylene glycols, ethylene oxide and other alkylene oxides, ethyleneimine, styrenesulphonates, ethyleneglycolacrylates and ethyleneglycol methacrylate (d) cyclodextrins, for example beta-cyclodextrin (e) mixtures thereof.
When the polymeric material is a copolymer it may be a statistical copolymer (heretofore also known as a random copolymer), a block copolymer, a graft copolymer or a hyperbranched copolymer. Co-monomers other than those listed above may also be included in addition to those listed if their presence does not destroy the water soluble or water dispersible nature of the resulting polymeric material.
Examples of suitable and preferred homopolymers include poly-vinylalcohol, poly-acrylic acid, poly-methacrylic acid, poly-acrylamides (such as poly-N-isopropylacrylamide), poly-methacrylamide; poly-acrylamines, poly-methyl-acrylamines, (such as polydimethylaminoethylmethacrylate and poly-N-morpholinoethylmethacrylate), polyvinylpyrrolidone, poly-styrenesulphonate, polyvinylimidazole, polyvinylpyridine, poly-2-ethyl-oxazoline poly-ethyleneimine and ethoxylated derivatives thereof.
Polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), poly(2-ethyl-2-oxazaline), polyvinyl alcohol (PVA) hydroxypropyl cellulose and hydroxypropyl-methyl cellulose (HPMC) and alginates are preferred polymeric carrier materials.
Preferred Surfactant Carrier Materials:
Where the carrier material is a surfactant, the surfactant may be non-ionic, anionic, cationic, amphoteric or zwitterionic.
Examples of suitable non-ionic surfactants include ethoxylated triglycerides; fatty alcohol ethoxylates; alkylphenol ethoxylates; fatty acid ethoxylates; fatty amide ethoxylates; fatty amine ethoxylates; sorbitan alkanoates; ethylated sorbitan alkanoates; alkyl ethoxylates; Pluronics™; alkyl polyglucosides; stearol ethoxylates; alkyl polyglycosides.
Examples of suitable anionic surfactants include alkylether sulfates; alkylether carboxylates; alkylbenzene sulfonates; alkylether phosphates; dialkyl sulfosuccinates; sarcosinates; alkyl sulfonates; soaps; alkyl sulfates; alkyl carboxylates; alkyl phosphates; paraffin sulfonates; secondary n-alkane sulfonates; alpha-olefin sulfonates; isethionate sulfonates.
Examples of suitable cationic surfactants include fatty amine salts; fatty diamine salts; quaternary ammonium compounds; phosphonium surfactants; sulfonium surfactants; sulfoxonium surfactants.
Examples of suitable zwitterionic surfactants include N-alkyl derivatives of amino acids (such as glycine, betaine, aminopropionic acid); imidazoline surfactants; amine oxides; amidobetaines.
Mixtures of surfactants may be used. In such mixtures there may be individual components which are liquid, provided that the carrier material overall, is a solid.
Alkoxylated nonionic's (especially the PEG/PPG Pluronic™ materials), phenol-ethoxylates (especially TRITON™ materials), alkyl sulphonates (especially SDS), ester surfactants (preferably sorbitan esters of the Span™ and Tween™ types) and cationics (especially cetyltrimethylammonium bromide—CTAB) are particularly preferred as surfactant carrier materials.
Preferred Inorganic Carrier Materials:
The carrier material can also be an water-soluble inorganic material which is neither a surfactant nor a polymer. Simple organic salts have been found suitable, particularly in admixture with polymeric and/or surfactant carrier materials as described above. Suitable salts include carbonate, bicarbonates, halides, sulphates, nitrates and acetates, particularly soluble salts of sodium, potassium and magnesium. Preferred materials include, sodium carbonate, sodium bicarbonate and sodium sulphate. These materials have the advantage that they are cheap and physiologically acceptable. They are also relatively inert as well as compatible with many materials found in pharmaceutical products.
Mixtures of carrier materials are advantageous. Preferred mixtures include combinations of surfactants and polymers. Which include at least one of:
a) Polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), hydroxypropyl cellulose and hydroxypropyl-methyl cellulose (HPMC), alginates and, at least one of; b) Alkoxylated nonionic's (especially the PEG/PPG Pluronic™ materials), phenol-ethoxylates (especially TRITON™ materials), alkyl sulphonates (especially SDS), ester surfactants (preferably sorbitan esters of the Span™ and Tween™ types) and cationics (especially cetyltrimethylammonium bromide—CTAB)
The carrier material can also be a water-soluble small organic material which is neither a surfactant, a polymer nor an inorganic carrier material. Simple organic sugars have been found to be suitable, particularly in admixture with a polymeric and/or surfactant carrier material as described above. Suitable small organic materials include mannitol, polydextrose, xylitol and inulin etc.
Non-Aqueous Solvent:
The compositions of the invention comprise a volatile, second non-aqueous solvent. This may either be miscible with the other solvents in pre-mix before drying or, together with those solvents may form an emulsion.
In one alternative form of the invention a single, non-aqueous solvent is employed in which can form a single phase with water in the presence of the statin and the carrier. Preferred solvents for these embodiments are polar, protic or aprotic solvents. Generally preferred solvents have a dipole moment greater than 1 and a dielectric constant greater than 4.5.
Particularly preferred solvents are selected from the group consisting of haloforms (preferably dichloromethane, chloroform), lower (C1-C10) alcohols (preferably methanol, ethanol, isopropanol, isobutanol), organic acids (preferably formic acid, acetic acid), amides (preferably formamide, N,N-dimethylformamide), nitrites (preferably aceto-nitrile), esters (preferably ethyl acetate) aldehydes and ketones (preferably methyl ethyl ketone, acetone), and other water miscible species comprising heteroatom bond with a suitably large dipole (preferably tetrahydrofuran, dialkylsulphoxide).
Haloforms, lower alcohols, ketones and dialkylsulphoxides are the most preferred solvents.
In another alternative form of the invention the non-aqueous solvent is not miscible with water and forms an emulsion.
The non-aqueous phase of the emulsion is preferably selected from one or more from the following group of volatile organic solvents:
alkanes, preferably heptane, n-hexane, isooctane, dodecane, decane; cyclic hydrocarbons, preferably toluene, xylene, cyclohexane; halogenated alkanes, preferably dichloromethane, dichloroethane, trichloromethane (chloroform), fluoro-trichloromethane and tetrachloroethane; esters preferably ethyl acetate; ketones preferably 2-butanone; ethers preferably diethyl ether; volatile cyclic silicones preferably either linear or cyclomethicones containing from 4 to 6 silicon units. Suitable examples include DC245 and DC345, both of which are available from Dow Corning Inc.
Preferred solvents include dichloromethane, chloroform, ethanol, acetone and dimethyl sulphoxide.
Preferred non-aqueous solvents, whether miscible or not have a boiling point of less than 150 Celsius and, more preferably, have a boiling point of less than 100 Celsius, so as to facilitate drying, particularly spray-drying under practical conditions and without use of specialised equipment. Preferably they are non-flammable, or have a flash point above the temperatures encountered in the method of the invention.
Preferably, the non-aqueous solvent comprises from about 10% to about 95% v/v of any emulsion formed, more preferably from about 20% to about 80% v/v. In the single phase method the level of solvent is preferably 20-100% v/v.
Particularly preferred solvents are alcohols, particularly ethanol and halogenated solvents, more preferably chlorine-containing solvents, most preferably solvents selected from (di- or tri-chloromethane).
Optional Cosurfactant:
In addition to the non-aqueous solvent an optional co-surfactant may be employed in the composition prior to the drying step. We have determined that the addition of a relatively small quantity of a volatile cosurfactant reduced the particle diameter of the material produced. This can have a significant impact on particle volume. For example, reduction from 297 nm to 252 nm corresponds to a particle size reduction of approximately 40%. Thus, the addition of a small quantity of co-surfactant offers a simple and inexpensive method for reducing the particle size of materials according to the present invention without changing the final product formulation.
Preferred co-surfactants are short chain alcohols or amine with a boiling point of <220° C.
Preferred co-surfactants are linear alcohols. Preferred co-surfactants are primary alcohols and amines.
Particularly preferred co-surfactants are selected from the group consisting of the 3-6 carbon alcohols. Suitable alcohol co-surfactants include n-propanol, n-butanol, n-pentanol, n-hexanol, hexylamine and mixtures thereof.
Preferably the co-surfactant is present in a quantity (by volume) less than the solvent preferably the volume ratio between the solvent and the co-surfactant falls in the range 100:40 to 100:2, more preferably 100:30 to 100:5.
Preferred Spray-Drying Feedstocks:
Typical spray drying feedstocks comprise:
a) a surfactant, b) at least one lower alcohol, c) more than 0.1% of at least one water-insoluble statin dissolved in the feedstock, d) a polymer, and, e) optional water
Preferred spray-drying feedstocks comprise:
a) at least one non-aqueous solvent selected from dichloromethane, chloroform, ethanol, acetone, and mixtures thereof, b) a surfactant selected from PEG co-polymer nonionic's (especially the PEG/PPG Pluronic™ materials), alkyl sulphonates (especially SDS), ester surfactants (preferably sorbitan esters of the Span™ and Tween™ types) and cationics (especially cetyltrimethylammonium bromide—CTAB) and mixtures thereof, c) more than 0.1% of at least one water-insoluble statin, d) a polymer selected from Polyethylene glycol (PEG), Polyvinyl alcohol (PVA), polyvinyl-pyrrolidone (PVP), hydroxypropyl cellulose and hydroxypropyl-methyl cellulose (HPMC), alginates and mixtures thereof, and e) optionally water.
The drying feed-stocks used in the present invention are either emulsions or solutions which preferably do not contain any solid matter and in particular preferably do not contain any undissolved statin.
It is particularly preferable that the level of the statin in the composition should be such that the loading in the dried composition is below 40% wt, and more preferably below 30% wt. Such compositions have the advantages of a small particle size and high effectiveness as discussed above.
Water-Dispersed Form:
On admixture of the water-soluble carrier material with water, the carrier dissolves and the water-insoluble statin is dispersed through the water in sufficiently fine form that it behaves like a soluble material in many respects. The particle size of the water-insoluble materials in the dry product is preferably such that, on solution in water the water-insoluble materials have a particle size of less than 1 micron as determined by the Malvern method described herein. It is believed that there is no significant reduction of particle size for the statin on dispersion of the solid form in water.
By applying the present invention significant levels of ‘water-insoluble’ materials can be brought into a state which is largely equivalent to true solution. When the dry product is dissolved in water it is possible to achieve optically clear solutions comprising more than 0.1%, preferably more than 0.5% and more preferably more than 1% of the water-insoluble material.
It is envisaged that the solution form will be a form suitable for administration to a patient either ‘as is’ or following further dilution. In the alternative, the solution form of embodiments of the invention may be combined with other active materials to yield a medicament suitable for use in combination therapy.
EXAMPLES
In order that the present invention may be further understood and carried forth into practice it is further described below with reference to non-limiting examples.
A range of formulations were produced based on different excipients, different active loadings, and different process conditions.
The excipients were chosen from hydroxypropyl cellulose (Klucel EF, Herlus), polyvinyl pyrrolidone (PVP k30, Aldrich), hydroxypropyl methyl cellulose (HPMC, Mw 10 k, 5 cps, Aldrich), polyethylene glycol (PEG, Mw 6,000, Fluka), Tween 80 (Aldrich), pluronic F68 (BASF), pluronic F127 (Aldrich), span 80 (Aldrich), cremphor RH40 (BASF), mannitol (Aldrich), and sodium alginate (Aldrich).
Active loadings varied from 10 wt % to 30 wt %, and the spray dry temperature varied from 120° C. to 160° C. Simvastatin particle size ranged from as small as 100 nm to 2 m.
Details of these formulations are listed as below:
Example 1
20 wt % Loadings
0.40 g Simvastatin, 1.00 g Klucel EF, 0.44 g HPMC, and 0.16 g Pluronic F68 were all dispersed into 100 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before adding 60 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 120° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 217 nm.
Example 2
20 wt % Loadings
0.40 g Simvastatin, 1.00 g Klucel EF, 0.34 g HPMC, 0.16 g Pluronic F127, and 0.10 g Tween 80 were all dispersed into 100 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before adding 60 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 120° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 125 nm.
Two dissolution tests based on a 20 mg simvastatin dose and an 80 mg simvastatin dose were carried out for formulation #15/39/28 following the standard USP2 test. The results are listed below;
Example 2a
Dissolution time, min
20 mg API
5
10
15
20
25
35
50
Equilibrium
% dissolution
25.6
66.9
71.4
85.9
83
89.3
92.5
100
Example 2b
Dissolution time, min
80 mg API
5
10
30
50
70
90
120
150
Equilibrium
% dissolution
15.1
31.8
51.8
63.4
69.6
80.4
92.8
95.8
100
Example 3
20 wt % Loadings
0.40 g Simvastatin, 1.00 g Klucel EF, and 0.60 g HPMC were all dispersed into 100 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before adding 60 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 277 nm.
Example 4
20 wt % Loadings
0.40 g Simvastatin, 1.44 g Klucel EF, and 0.16 g PEG 6000 were all dispersed into 100 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour and a clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a translucent nanodispersion with a particle size of 467 nm.
Example 5
20 wt % Loadings
0.40 g Simvastatin, 1.00 g Klucel EF, 0.18 g HPMC, 0.16 g PEG 6000, 0.16 g Pluronic F127, and 0.10 g Tween 80 were all dispersed into 100 ml absolute ethanol. The ethanol suspension was stirred intensively with magnetic bar for about half hour before adding 60 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 105 nm.
Example 6
20 wt % Loadings
0.40 g Simvastatin, 1.34 g Klucel EF, 0.16 g Pluronic F127, and 0.10 g Cremphor RH40 were all dispersed into 100 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before adding 60 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 120 nm.
Two dissolution tests based on a 20 mg simvastatin dose and an 80 mg simvastatin dose were carried out for formulation #15/39/41 following the standard USP2 test. The results are given below.
Example 6a
Dissolution time, min
20 mg API
5
10
15
20
25
Equilibrium
% dissolution
40.6
54.3
80.8
79.8
102.8
100
Example 6b
Dissolution time, min
80 mg API
5
10
40
60
80
100
Equilibrium
% dissolution
61.1
75.7
85.0
89.5
93.2
100
100
Example 7
20 wt % Loadings
0.40 g Simvastatin, 1.18 g Klucel EF, 0.16 g Pluronic F68, 0.16 g Pluronic F127, and 0.10 g Span 80 were all dispersed into 100 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before adding 10 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 162 nm.
Example 8
20 wt % Loadings
0.40 g Simvastatin, 1.40 g Klucel EF, 0.10 g Tween 80, and 0.10 g Span 80 were all dispersed into 100 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour and a clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 139 nm.
Example 9
30 wt % Loadings
0.30 g Simvastatin, 0.57 g Klucel EF, 0.05 g PEG 6000, 0.05 g Pluronic F127, and 0.03 g Tween 80 were all dispersed into 50 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before adding 30 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 202 nm.
Example 10
30 wt % Loadings
0.30 g Simvastatin, 0.65 g Klucel EF, 0.025 g Tween 80, and 0.025 g Span 80 were all dispersed into 50 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour and a clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a translucent nanodispersion with a particle size of 328 nm.
Example 11
20 wt % Loadings
0.20 g Simvastatin, 0.40 g Klucel EF, 0.10 g Pluronic F127, 0.10 g Tween 80, and 0.20 g Mannitol were all dispersed into 50 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before added 30 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 140° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 151 nm.
A dissolution test based on a 20 mg simvastatin dose was carried out for formulation obtained from example 11 following the standard USP2 test. The results showed a fast dissolution formulation.
Example 11a
Dissolution time, min
20 mg API
5
10
15
Equilibrium
% dissolution
90.2
96.3
99.2
100
Example 12
20 wt % Loadings
0.20 g Simvastatin, 0.50 g Klucel EF, 0.10 g Pluronic F127, and 0.20 g Mannitol were all dispersed into 50 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before adding 30 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 140° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 211 nm.
A dissolution test based on a 20 mg simvastatin dose was carried out for formulation #15/39/77 following the standard USP2 test. The results showed a very fast dissolution formulation.
Example 12a
Dissolution time, min
20 mg API
5
10
15
Equilibrium
% dissolution
96.5
98.5
98.9
100
Example 13
20 wt % Loadings
0.20 g Simvastatin, 0.60 g Klucel EF, 0.05 g Pluronic F127, 0.05 g Tween 80, and 0.10 g Mannitol were all dispersed into 50 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour before adding 30 ml distilled water. A clear solution was obtained.
The solution was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 145 nm.
Example 14
20 wt % Loadings
0.20 g Simvastatin, 0.60 g Klucel EF, 0.10 g Pluronic F127, 0.025 g Tween 80, and 0.025 g Span 80 were all dispersed into 50 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour and a clear ethanol solution was formed. 0.05 g Sodium alginate was dissolved into 30 ml distilled water. The ethanol solution and the aqueous solution were mixed together and a clear mixture was obtained.
The mixture was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 206 nm.
Example 15
20 wt % Loadings
0.20 g Simvastatin, 0.60 g Klucel EF, 0.15 g Pluronic F127 were all dispersed into 50 ml absolute ethanol. The ethanol suspension was stirred intensively with a magnetic bar for about half hour. 0.05 g Sodium alginate was dissolved into 30 ml distilled water. The ethanol dispersion and the aqueous solution were mixed together and a clear mixture was obtained.
The mixture was then spray dried with a BUCHI Mini B-290 spray dryer at 160° C. with the liquid feed rate at 2.5 ml/min. A white free flowing powder was obtained.
20 mg dried powder was dispersed into 10 ml distilled water, giving a crystal clear nanodispersion with a particle size of 276 nm.
A dissolution test based on a 20 mg simvastatin dose was carried out for formulation Example 15 following the standard USP2 test. The results showed a very slow dissolution formulation.
Ex. 15
Dissolution time, min
20 mg API
5
10
20
30
40
50
60
80
100
120
Equilibrium
% dissolution
57.1
61.8
75.8
83.5
87.6
92.5
95.5
92.7
99.8
101.3
100
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A process for the production of a composition comprising a water-insoluble statin which comprises the steps of: a) providing a mixture comprising: i) a water-insoluble statin ii) a water soluble carrier, iii) a solvent for each of the statin and the carrier, and b) spray-drying the mixture to remove the or each solvent and obtain a substantially solvent-free nano-dispersion of the statin in the carrier.
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RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Patent Application Ser. No. 017,296, filed Mar. 5, 1979, now abandoned.
BACKGROUND OF THE INVENTION
In a large percentage of forming machines currently employed in the manufacture of nails, wire is first straightened through a series of rollers and is then incrementally fed into the machine for subsequent nail forming. The wire to be formed in the machine is passed through a sliding platform on which are mounted straightening rolls and some type of wire gripping apparatus. During the nail forming sequence, the sliding platform is moved out from the machine a distance equal to the length of the nail to be formed. This movement permits the straightening rolls to work on the wire. When the platform reaches the end of its outward travel and begins to move inwardly, the wire gripping apparatus is wedged against the wire and establishes a feed of wire into the nail forming machine. The movement of the sliding platform is sequenced through mechanical linkages which connect the rotating end of the machine's main crankshaft to the platform.
The mechanical linkages between the sliding wire feed platform and its crankshaft include two links and four pivot points. Wear at these pivot points makes it difficult not only to set up the nail machine initially for production, but also makes it difficult to maintain consistent repeatability in the length of nails produced. Additionally, the inertial forces transmitted to the end of the crankshaft as the linkage operates causes severe problems in the area of crankshaft alignment and fracture. On the average, applicant has found that linkage and/or crankshaft components of the nail machine require replacement every two hundred (200) hours of operation.
SUMMARY OF THE INVENTION
The present invention is addressed to a wire feed mechanism for use in conjunction with a nail forming machine. The wire feed mechanism is configured having a direct connection with the reciprocating hammerslide of the nail forming machine which is used for forming the head of the nail. The hammerslide is movable between a retracted position (in which it is farthest away from its head forming position) and an extended position (in which it is at its nail head forming location). Consequently, due to the connection between the wire feed mechanism and the hammerslide, there is a direct relationship established between hammerslide movement and wire feeding. This relationship obviates the need for cumbersome and wear prone linkages previously employed in such machines.
The wire feed mechanism includes a selectively operable gripper assembly and an apparatus cooperatively associated with the assembly for adjusting the length of wire gripped and subsequently fed into the nail forming machine. The gripper assembly is attached to one end of the linkage with the hammerslide and thus, is movable with the hammerslide for sequentially feeding wire into the machine. The apparatus for adjusting the length of wire gripped and fed into the nail forming machine by the gripper apparatus is operative to move the gripper apparatus out of engagement with the wire for a given distance of its travel for selectively decreasing the distance the gripper apparatus is in gripping engagement with the wire from the total stroke length of the gripper apparatus. Hence, through the use of the present wire feed mechanism, a simple and easily maintainable wire feed assembly is attained.
Accordingly, it is a general object and feature of the present invention to provide an apparatus for feeding wire into a nail forming machine of the variety having a reciprocating hammerslide, the wire feed mechanism being configured having an actuating linkage provided between the hammerslide and the remainder of the wire feed mechanism.
It is another general object and feature of the present invention to provide an apparatus for feeding wire into a nail forming machine for the type having a reciprocating hammerslide, the wire feed mechanism including a linkage with the hammerslide for selectively actuating the gripping portion of the wire feed mechanism and providing an easily set-up and efficient wire feed mechanism.
It is yet another object and feature of the present invention to provide a wire feed mechanism having an easily set, accurate and efficiently repeatable wire length adjustment mechanism for controlling the length of wire to be fed into the nail forming machine.
Other objects and features of the present invention will, in part, be obvious and will, in part, become apparent as the following description proceeds. The features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its structure and its operation together with the additional objects and advantages thereof will best be understood from the following description of the preferred embodiment of the present invention when read in conjunction with the accompanying drawings wherein:
FIG. 1 is a plan view of a typical type of nail machine with which the present invention is associated, but which indicates the usual type of wire feeding mechanism;
FIG. 2 is a plan view of the nail machine of FIG. 1 with appropriate modifications showing the wire feed mechanism of the present invention combined therewith;
FIG. 3 is a plan view of one portion of the wire feed mechanism of the present invention indicating the movement and operation of the wire feed mechanism; and
FIG. 4 is a front elevational view of the mechanism shown in FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Looking to FIG. 1, there is shown a typical nail forming machine 10. The nail machine 10 is of known design and operation and will be described herein only insofar as the specific components of the machine relate to the present invention.
A motor 12 provides, through appropriate beltings 14, the necessary driving energy for the nail forming machine 10. The nail forming machine 10 has a main crankshaft indicated at 16 through which power is passed to the various moving components of the machine as well as for sequentially advancing wire, indicated at 18, into the machine 10. Located on the wire feed side of the nail forming machine 10 is a sliding wire feed platform 20. This sliding wire feed platform is composed of a wire straightener mechanism 22 and a roller feed arrangement 24. Wire to be formed in the machine passes through the sliding platform 20 upon which are mounted the straightening rolls 22 and the roller feed arrangement including a spring loaded wire grip cam 26. During the nail forming sequence, this sliding platform 20 is moved out from the machine a distance equal to the length of the nail being formed. This movement permits the straightening rolls to work on the wire. When the platform 20 reaches the end of its outward travel and begins to move inwardly again, the spring loaded wire grip cam 26 wedges against the wire and establishes a feed of wire into the machine.
The movement of the sliding platform is sequenced through a mechanical linkage assembly indicated generally at 28 which connects the wire forming machine's main crankshaft 16 to the sliding platform 20. The mechanical linkage assembly 28 includes a pivotal arm 30 pivotally movable about a pivot point 32, linkage points 34 and 36, and a linkage arm 38. Due to an offset of the linkage point 36 from the axis of the main crankshaft 16 it can be seen that a reciprocating movement of the arm 30 is made resulting in movement of the sliding platform between its previously mentioned outward and inward positions.
The linkage between the sliding wire feed platform 20 and the crankshaft 16 is comprised of two links and four pivot points. Wear at these pivot points makes it difficult to not only set up the machine initially for production, but also to maintain repeatability in the length of nails produced. The inertial forces transmitted to the end of the crankshaft as the linkage operates causes severe crankshaft alignment and fracture problems. Applicant has found that the linkage and/or crankshaft components of the machine require replacement approximately every two hundred (200) hours of operation. It is obvious that the linkage provided between the main crankshaft through the two linkage arms 30 and 38, as well as the four pivot points for sequentially advancing incremental portions of a wire into a nail forming machine, are cumbersome, complicated and require frequent maintenance.
The present invention utilizes the reciprocating movement of a hammerslide element 40 located in the center of the nail forming machine 10 to implement wire feed to the forming die 42 therein. The hammerslide 40 is driven (through appropriate linkage arrangements) by the main crankshaft 16 both toward and away from a nail head forming die 42. The operation of a hammerslide and associated die is not novel and need not be further described herein. The hammerslide 40 is movable from a retracted position as shown in FIGS. 1 and 2 to an extended position in which a front portion 44 thereof is moved into a butting engagement with the nail head forming die 42. It is the reciprocating movement of the hammerslide between its two positions which forms the operational basis of the present wire feed mechanism.
The wire feed device of the present invention is shown generally at 50. A connecting rod 52 is attached at one end to the hammerslide 40 through appropriate connectors indicated generally as 54. The connecting rod 52 is disposed outwardly of the hammerslide 40 to extend longitudinally of the machine and is attached at its other end to the wire feed mechanism described hereinafter. In extending forwardly, the connecting rod 52 passes through, and is slidably supported by, a bushing 56 located at the entrance of the nail forming machine 10. The forward end of the rod 52 is attached to a base 58 of the wire feed mechanism shown in detail in FIGS. 3 and 4. Due to a rigid attachment of the rod 52 with the base 58, there is a resultant reciprocating movement of this member of the wire feed device 50 with the reciprocating movement of the hammerslide 40.
The wire feed device 50 of the present invention is best described with reference to FIGS. 3 and 4. As shown, the device comprises a movable frame 58 formed of an angle member, one arm 60 of which is adapted to weldedly attach the forward end of connecting rod 52 whereby the reciprocating movement of the hammerslide 40 is imparted to the frame. The other arm 62 of the angle member forming the frame 58 rigidly attaches to its back side a block 64 having a surface 66 arranged to be in facing relation to, and closely adjacent, the path along which the wire 18 is adapted to travel in being fed from the straightener 22 to the forming die 42. The surface 66 forms backing support for the wire 18 and coacts with dog grip 68, as hereinafter described, to affix the wire to the frame 58 when the latter is moved in the wire feed direction. An elongate V-notch 70 formed in the surface 66 assists in affixing the wire 18 to the surface and also serves in guiding the wire along its feed path.
Dog grip 68 which operates to affix the wire 18 to the movable frame is formed as an elongated arm at an intermediate location along which has welded thereto a pivot pin 72 that is pivotally received in an opening (not shown) in the arm 62 of the frame 58. The outer end of the pin 72 is threaded to receive lock nut 74 to retain the dog grip 68 on the frame.
The dog grip 68 is provided at one end with a chisel point 76 formed at the convergence of the surfaces 78 and 80. As shown, the leading surface 78 is cut at a greater rake angle than the trailing surface 80. By means of this construction the chisel point 76 of dog grip 68 is adapted to bitingly engage a wire 18 when the frame 58 is caused to move in the wire feed direction but simply slide along the wire when the frame moves in the opposite direction.
The other end of the arm forming dog grip 68 is provided with a rigidly secured rod 82, one end of which mounts a cam follower 84 which may be rotatable or fixed with respect to the rod. At its other end the rod 82 fixedly mounts a spring retention post 86 adapted to receive one end of a coiled spring 88. The other end of the spring 88 is received on a similar post 90 that is threadedly secured in an opening in plate 92 fixed to the frame 58 and block 64. The spring 88 functions to normally bias the chisel point 76 of dog grip 68 toward the facing surface 66 of the block 64 and into bearing relation with a wire 18 extending therealong in the notch 70.
It will be appreciated that the apparatus thus far described is capable of effecting the feed of wire 18 from the straightener 22 toward the forming die 42 a distance commensurate with the length of stroke of the hammerslide 40. This constitutes the maximum length of feed the mechanism 50 is capable of imparting to the wire 18. Means to selectively regulate the length of feed of the wire 18 with each hammerslide stroke includes a cam body 94 mounted via mounting bracket 96 on the machine 10 intermediate the wire straightener 22 and the entry end of the machine. The body 94 is connected to the bracket 96 by the threaded engagement of nut 98 with the threaded end of a stud 100 that depends from the body. The stud 100 extends through a slot 102 in the bracket 96, which slot is elongated in a direction parallel with the wire feed path thereby enabling the body 94 to be adjustably positioned therealong.
The upper surface 104 of the cam body 94, as shown best in FIG. 3, is operative to engage the follower 84 on the dog grip 68 to urge the chisel point 76 in opposition to the spring bias away from the surface 66 and wire 18. Thus, the length of wire feed to the forming die can be altered by simply adjusting the position of the cam body 94 on the mounting bracket 96.
The operation of the hereindescribed invention is as follows. With the hammerslide 44 at the forward terminous of its stroke, i.e. coacting with the forming die 42 in its nailheadforming position, the frame 52 of the device 50 is disposed in the position shown in phantom lines in FIG. 3. In this position the follower 84 is caused to engage the surface 104 of cam body 94 thereby urging the dog grip 68 out of engagement with the wire 18. As the hammerslide 44 moves toward its retracted position (to the right in FIG. 2) the follower 84 is moved from the cam body 94 permitting the spring 88 to bias the dog grip 68 counterclockwise about its pivot point and the chisel point 76 into biting engagement with the wire 18 against the surface 66 of block 64. So engaged, the wire 18 is affixed to the frame 52 and caused to move therewith through the remainder of the retracting movement of the hammerslide thereby placing the leading end of the wire in the forming die 42.
Upon reaching the end of its retracting motion, the hammerslide reverses its direction of movement and begins to move toward the forming die 42 (i.e. toward the left in FIG. 2) whereupon, due to the inclination of the trailing surface 80 on dog grip 68 the biting engagement of the chisel point 76 with the wire 18 is released and the dog grip is caused to slide along the wire, the wire being retained in place in the notch 70 of the block 64. Movement of the movable frame 58 of feed device 50 free of the wire 18 is augmented by the fact that, as usual in the nail forming machines of the described type, the wire 18 is grasped by the forming die 42 during this portion of the operating cycle of the machine.
As the frame 58 continues to move to the left, toward its full-forward position, the follower 84 engages the cam body 94 rotating the dog grip 68 clockwise out of contact with the wire 18. The dog grip 68 remains in this position through the remainder of the forward stroke of the hammerslide 44 and continues in this position while the direction of movement of the hammerslide and frame 58 is reversed. When the follower 84 again drops from the cam body 94, the chisel point 76 is returned to biting engagement with the wire 18 and the latter is moved another incremental distance.
To alter the length of feed of the wire 18 in relation to the stroke of the hammerslide 44 the position of the cam body 94 on the mounting bracket 96 need only be changed. Thus to extend the length of feed of the wire the cam body must be moved to the left from the position shown in FIG. 3. To shorten the length of feed the cam body must be moved to the right.
From the foregoing, it will be seen that there is provided a simple, efficient, and easily maintained wire feed mechanism and wire length adjustment apparatus for use with a wire forming machine. The lack of complicated components and the simplification of the moving parts included in the present invention provide for a reliable and easily set up arrangement without the need for cumbersome and wearable components used previously.
While certain changes may be made in the above noted apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense.
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A wire feed mechanism for use in conjunction with a nail forming machine. The wire feed includes a wire clamping device connected through appropriate linkages to a reciprocating hammerslide located within the nail machine. The hammerslide is movable between extended and retracted positions for forming the nail head. Due to the direct positive linkage between the hammerslide and the wire clamping device, feeding movement of the wire into the nail machine is achieved as a direct result of hammerslide movement, thereby obviating the need for cumbersome and elaborate linkages currently in use.
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FIELD OF THE INVENTION
The present invention relates to shower door assembly, and in particular, to adjustment assembly used therein which achieves fast assembling and adjustment.
BACKGROUND OF THE INVENTION
Doors used for shower enclosure are often mounted against wall surfaces and the doors thus mounted are kept as vertical as possible. However, the wall surfaces of buildings are often not exactly vertical, for example, titled toward outside/inside by an angle. Therefore, if mounted completely along the wall surface, the doors may not be smoothly opened or closed. In this regard, it is necessary to adjust the distances between the top/bottom end of a door and a wall surface so as to keep the door in a vertical position.
To achieve this adjustment, a door assembly usually comprises a stationary frame to be attached to a wall surface, and a movable frame connected with a door panel, such as a glass door panel. The stationary frame is firstly attached to the wall surface and then the movable frame is moved toward the stationary frame, during which the distances between the top and bottom ends of the movable frame, and the stationary frame are such adjusted that the movable frame is in a vertical position, and thus so is the door panel. The stationary and movable frames are finally connected to each other by drilling thereon and by using fasteners.
However, in one aspect, the drilling operation requires at least two people to cooperate and is very time-consuming. In another aspect, the drilling may inadvertently cause damages to the surfaces of the frames generally made of aluminum materials, which is undesirable to consumers.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a shower door assembly which comprises a stationary frame, a movable frame and at least one adjustment assembly disposed between the stationary frame and the movable frame, the at least one adjustment assembly comprising an adjustment device and a locking device, the adjustment device being detachably connected to the stationary frame and having an extension, the locking device being detachably connected to the movable frame and comprising
two opposite sides and a bottom side connecting said two opposite sides, the opposite sides and the bottom side defining a first cavity having a first depth and a second cavity having a second smaller depth, the first and second cavity jointly receiving the extension of the adjustment device;
a blocking element, a pressing element and an elastic element disposed between the blocking element and the pressing element being located in the first cavity, the elastic element being arc-shaped when unlocked, an interface between the first and the second cavity having at least a portion forming an inclined surface projecting to the blocking element; and
a driving device comprising a cam mechanism and a sliding element in the first cavity, the sliding element has one end in contact with the pressing element and the other end sliding along with the inclined surface when driven by the cam mechanism so as to push the pressing element toward the blocking element, and thus reduce the curvature of the arc-shaped elastic element until the elastic element is engaged with the adjustment device.
Preferably, the arc-shaped elastic element has an intrados facing towards the blocking element.
In one embodiment, the blocking element comprises a guiding rod. The pressing element and the arc-shaped each has a through hole, respectively, through which the guiding rod can pass so as to guide the movements of the pressing element and the elastic element within the first cavity.
In one embodiment, the pressing element has a guiding groove for receiving the one end of the sliding element. The guiding groove has a width large enough to maintain the one end within the guiding groove when the sliding element is sliding along the inclined surface.
In one embodiment, the locking device has a threaded hole penetrating through one of the two opposite sides such that when the locking device and the adjustment device are engaged, the engagement can be enhanced by screwing a screw into the threaded hole. Preferably, in this embodiment, a spacer element is disposed within the second cavity in a gap formed by the extension of the adjustment device. The spacer element is provided to prevent deformation of the elastic element already flattened, which may be caused by excessive force applied by the screwing as mentioned above.
In one embodiment, the pressing element has platforms at two sides, for in contact with the two opposite sides of the locking device, so as to prevent turnover of the pressing element during movement.
In one embodiment, the locking device has a receiving groove at one of the two opposite sides for receiving the cam mechanism.
In one embodiment, a surface of the extension of the adjustment device that is in contact with the arc-shaped elastic element is provided with teeth, such that the elastic element will be imbedded between two adjacent teeth when the elastic element is pressed, so as to enhance the engagement of the adjustment device and the locking device.
In one embodiment, the locking device is attached to the movable frame at at least two different linkage points, such that the locking device will not rotate about the movable frame.
In one embodiment, the arc-shaped elastic element is flattened when pressed, i.e., the curvature is zero.
In one embodiment, the stationary frame has two sidewalls, each received within respective slot provided with the locking device.
In one embodiment, the shower door assembly comprises two adjustment assemblies located at terminal ends of the stationary/movable frames, and the adjustment assemblies are disposed in opposite.
In one embodiment, the arc-shaped elastic element is constituted by a single metal sheet or a plurality of metal sheets that are disposed side by side. The single metal sheet, or the plurality of metal sheets as a whole, has a thickness between about 0.1 mm and no more than 0.2 mm, preferably 0.15 mm.
The shower door assembly provided by the present invention transfers the rotation of the cam mechanism to the translational movement of the pressing element by the inclined surface and the sliding element. The movement of the pressing element towards the blocking element makes the arc-shaped elastic element disposed there between flattened, such that the lateral width of the elastic element increases, causing engagement with the extension of the adjustment device. Therefore, the adjustment device is locked by the locking device and thus immovable, the relative position between the stationary frame and the movable frame is thus fixed. When the cam mechanism is counter-rotated, the arc-shaped elastic element will disengage with the adjustment device due to the restoring force of the elastic element and return to unlocked state. The adjustment device can achieve fast assembling and adjustment of the shower door and, in the meantime, is able to lock and release by minimum force.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 schematically and partially shows a locking device according to one embodiment of the invention.
FIG. 2 shows the locking device of FIG. 1 from another perspective of view, showing more elements.
FIG. 3 is an exemplary pressing element of the invention.
FIG. 4 is an exemplary sliding element of the invention.
FIG. 5 shows a sectional view of an exemplary locking device.
FIG. 6 shows an exemplary cam mechanism of the invention.
FIG. 7 shows an exemplary arc-shaped element of the invention.
FIG. 8 shows an exemplary adjustment device of the invention.
FIG. 9 is an exploded view showing a shower door assembly of the invention.
FIG. 10 shows an assembling state of the shower door assembly, wherein the door assembly is unlocked.
FIG. 11 shows another assembling state of the shower door assembly, wherein the door assembly is locked.
FIG. 12 is a sectional view of the state as shown in FIG. 10 .
FIG. 13 is a sectional view of the state as shown in FIG. 11 .
Elements that are irrelevant of the spirit of the invention is omitted from the drawings for clarity purpose.
DETAILED DESCRIPTION
The invention will now be described in more detail in reference to preferable examples in conjugation with the accompanied drawings.
FIG. 1 partially shows a locking device 300 according to one embodiment of the invention. The locking device 300 is substantially rectangular in shape. Two opposite sides 301 , 302 and a bottom side 303 jointly define an open internal space. The internal space comprises a first cavity 310 and a second cavity 320 . The second cavity 320 has a less depth than that of the first cavity 310 . An interface between the first and second cavities 310 , 320 has at least a part forming an inclined surface 330 projecting toward the first cavity 310 .
The locking device 300 is coupled to a movable frame 200 (see FIG. 9 ) at at least two linkage points 313 , 383 , such that the locking device 300 will not rotate around the movable frame 200 .
In FIG. 1 , a blocking element 311 is provided within the first cavity 310 at an end that is away from the bottom side 303 . In this example, the blocking element 311 has a guiding rod 312 for guiding the movements of other elements in the first cavity 31 .
FIG. 2 shows more elements of the locking device 300 . In the first cavity 310 is disposed a pressing element 315 , and an arc-shaped elastic element 314 between the pressing element 315 and the foresaid blocking element 311 . The arc-shaped elastic element 314 has an intrados facing toward the blocking element 311 . The pressing element 315 is able to be moved within the first cavity 310 in relation to the blocking element 311 so as to press or release from the elastic element 314 to change the curvature, and in turn the lateral width, of the elastic element 314 .
A sliding element 316 is further provided in the first cavity 310 and has one end in contact with the pressing element 315 , and the other end in contact with and sliding along the inclined surface 330 . Therefore, when actuated by the cam mechanism 317 , the sliding element 316 will slide along the inclined surface and push the pressing element to move toward the blocking element 311 . The locking device 300 has a groove 304 at its one side for receiving the cam mechanism 317 . FIG. 2 shows only a handle 371 of the cam mechanism 317 .
FIGS. 3 and 4 show an exemplary pressing element 315 and a sliding element 316 , respectively. The pressing element 315 comprises a sliding groove 353 for receiving the one end 361 of the sliding element 316 . The sliding groove 353 is wide enough such that the end 361 is always maintained therein during the slide of the sliding element 316 along the inclined surface 330 . The pressing element 315 has two platforms 352 at two sides for contacting the two opposite sides 301 , 302 of the locking device 300 , so as to prevent from overturn of the pressing element 315 during its movement. In this example, the pressing element 315 is provided with a through hole 354 , through which the guiding rod 312 of the blocking element 311 can pass, so as to guide the movement of the pressing element 315 .
The sliding element 316 comprises the one end 361 received within the sliding groove 353 , a contact surface 362 in contact with the cam mechanism 317 , and the other end 363 in contact with and sliding along the inclined surface 330 . When rotated, the cam mechanism 317 pushes, through the contact surface 362 , the sliding element 316 to rotate about the end 361 , and in the meantime, the other end 363 slides along the inclined surface 330 . Because the inclined surface 330 is projected toward the first cavity 310 , the sliding element 316 pushes the pressing element 315 to move toward the blocking element 311 .
FIG. 5 is a sectional view of the locking device, showing the relative positions of respective element in the first cavity 310 and the cooperation between them.
FIG. 6 shows an exemplary cam mechanism 317 which comprises a handle 371 and a cam portion 372 . The handle 371 is provided to facilitate rotation operation of the cam mechanism and the cam portion 372 is used for contact with the contact surface 362 of the sliding element 316 . The cam mechanism 317 may be attached to the side 301 by pins such that it may rotate about the side 301 , such that the cam portion 372 is in contact with the contact surface 362 to push the sliding element 316 to move.
FIG. 7 shows an exemplary elastic element 314 which has an intrados preferably facing toward the blocking element 311 . The elastic element 314 preferably has a through hole 341 through which the guiding rod 312 can pass to guide the movement of the elastic element 314 . When pressed by the pressing element 315 , the curvature of the elastic element 314 will decrease, so the lateral width increases. In one example, the curvature of the elastic element 314 is reduced to zero, i.e., the lateral width reaches maximum value and the elastic element 314 is flattened. The arc-shaped element can be a single metal sheet, or a plurality of metal sheets arranged side by side, so as to provide both suitable elastic force and strength. In the example, the elastic element has a thickness of about 0.15 mm. A thickness more than 0.2 mm may not provide sufficient elastic force and less than 0.1 mm may not provide sufficient strength.
FIG. 8 shows an exemplary adjustment device 400 comprising a securing portion 420 detachably connected to the stationary frame 100 , and an extension 410 . The inner surface of the extension is distributed with a plurality of teeth 411 . The teeth are provided to achieve more close and reliable engagement with the locking device 300 .
FIG. 9 schematically shows a shower door assembly of the present invention. The shower door assembly comprises a stationary frame 100 , a movable frame 200 , and two adjustment assemblies connected between the stationary frame 100 and the movable frame 200 , with each of the two adjustment assemblies being located at respective ends of the stationary frame/movable frame. Each adjustment assembly is consisted of the locking device 300 and the adjustment device 400 , the relative position and cooperation between them are shown in the figure. The movable frame 200 is coupled with a pivot door 250 which can be, for example, a glass door. The pivot door 250 may be connected to the movable frame 200 by suitable methods, for example by the locking device 300 . For example, a through hole can be provided on the locking device 300 , through which a pivot shaft of the pivot door can pass so as to be linked with the locking device 300 .
As shown in FIG. 9 , the stationary frame 100 have two sidewalls 101 , 102 which, when assembling, may be inserted into respective slot 381 , 382 (see FIG. 1 ) of the locking device 300 .
FIG. 10 shows the shower door assembly in a first state wherein the locking device and the adjustment device are combined, but the movable frame 200 and the stationary frame 100 are not locked. FIG. 12 shows a top view of the shower door assembly in this state. As shown, the cam mechanism 317 is in an open position and the sliding element 316 is not actuated. The elastic element 314 is thus in an uncompressed condition. The movable frame 200 and the stationary frame 100 can freely move with respect to each other.
FIG. 11 shows the shower door assembly in a second state wherein the locking and adjustment devices are locked together, so that the relative position between stationary frame 100 and the movable frame 200 can not be changed. FIG. 13 shows a top view of the shower door assembly in this state. As shown, the cam mechanism 317 is in a close position and received within the receiving groove 304 . The sliding element 316 is actuated to slide along the inclined surface 330 , so as to push the pressing element 315 to move towards the blocking element 311 . The elastic element 314 will then be pressed to gradually become flat. The lateral width of the elastic element 314 increases and eventually engages with the extension 410 of the adjustment device, such that the adjustment device is pressed against the two opposite sides of the locking device and therefore immovable in relation to the movable frame 200 . The stationary frame 100 is therefore immovable in relation to the movable frame 200 .
Optionally, in this example, the locking device 300 is provided with a threaded hole 305 penetrating through one side of the locking device. When the adjustment device 400 and the locking device 300 is locked, a screw 325 can be screwed into the threaded hole and abutted against the extension 410 so as to enhance the engagement between the flattened elastic element and the extension. On the other hand, in order not to cause unrecoverable deformation to the elastic element, it is preferably that, in the second cavity 320 , a spacer element 321 is provided in a space formed by the extension.
It should be understood that various example embodiments have been described with reference to the accompanying drawings in which only some example embodiments are shown. The present invention, however, may be embodied in many alternate forms and should not be construed as limited to only the example embodiments set forth herein.
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A shower door assembly with at least one adjustment assembly has an adjustment device and a locking device. The locking device includes a blocking element, a pressing element and an elastic element between the blocking element and the pressing element. The elastic element is arc-shaped when unlocked. An inclined surface projects to the blocking element. The curvature of the elastic element is thus reduced until it engages with the adjustment device. A driving device includes a cam mechanism and a sliding element having one end in contact with the pressing element and the other end sliding along with the inclined surface when driven by the cam mechanism so as to push the pressing element toward the blocking element, and thus reduce the curvature of the arc-shaped elastic element until the elastic element is engaged with the adjustment device.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Provisional patent application Ser. No. 62/291,506 filed Feb. 4, 2016, by the present inventor.
BACKGROUND
Prior Art
The following is a tabulation of some prior art that presently appears relevant:
Kind
Pat. No.
Code
Issue Date
Patentee
U.S. Patents
8,424,125
B2
Apr. 23, 2013
A. M. Anderson
4,137,579
Feb. 6, 1979
P. S. Soler
5,737,779
Apr. 14, 1998
R. H. Haddock
4,282,611
Aug. 11, 1981
G. L. O'Day
5,153,947
Oct. 13, 1992
E. C. Markles
5,390,374
Feb. 21, 1995
S. E. Hubrig, et al.
6,079,057
Jun. 27, 2000
P. M. Mette
5,655,230
Aug. 12, 1997
J. H. Corbin
U.S. Pat. application Publications
2012/0246816
A1
Oct, 4, 2012
S. Jung
Nonpatent Literature Documents
Potty
Weeman
http://www.pottyscotty.com/mi-scotty-00032.html
Scotty,
Urinal,
Garvin,
The Main
http://www.themaindrain.com/
Dan,
Drain,
The conventional toilet is a heavy porcelain receptacle that is bolted to the floor and designed to receive liquid and solid waste. The conventional toilet is comprised of a bowl, pivotable seat and cover, water-tank, internal J-water trap connecting the bowl to a sewer drain, and flushing mechanism to flush water and waste from the bowl to the sewer drain. When the seat and cover is lifted to an upright position, the toilet is commonly used as a urinal for males while standing.
Using the toilet as a urinal in this manner causes a few disadvantages such as the mess left behind, the seat being left upright and unready for the next user who wishes to sit, and the over-consumption of water. The mess left behind can be attributed to the distance between the discharging member of the male and the toilet-bowl and the design of the toilet. This distance allows more opportunity for the urine stream to miss the interior of the toilet bowl. Furthermore, once missed, the urine stream splashes against the rim and sides of the bowl creating a greater mess. Even if the urine stream makes it into the toilet, there is no sure prevention against splashing out the water sitting inside the bowl, and even minute traces of the urine stream can splash out when hitting against the interior of the bowl. This remaining mess causes grief and frustration to and between all users of the facility, relieved only by the constant cleaning of the toilet and surrounding area or by requiring all male users to sit uncomfortably for urination.
Although leaving the seat in the upright position is not considered revolting by most people, the courtesy of lowering the seat can be much appreciated in all homes. For homes that require the courtesy, the only solution is to train (with much frustration) all males to put the seat down every time or to force the males to sit uncomfortably for urination.
Contemporarily, manufacturers have determined that to effectively flush solid waste through the J-water trap an amount of 1.25 gallons and 1.65 gallons of water are needed per flush, and have designed their toilets accordingly. Water consumption of a gallon and a half may not seem like much, but multiply it for every time the toilet is used during the day, for every person, and the volume of water devoted to human waste becomes staggering. There are several toilet kits on the market that include a second lever and flushing mechanism to flush with less water for liquid waste, about 1 gallon, as a less forceful flush is required. In regions where drought is severe, most do not flush for liquid waste, as it does not create much unpleasant odor or staining. With this in consideration, a dilution of water would help to counter whatever odor or stains may occur.
Although an area is designated for toilets in all bathrooms, most are limited to a small area and do not permit the space for a second waste receptacle intended for male urination. Furthermore, the water pressure found in residential areas does not permit the installation of urinals with a flushometer, which are commonly found in commercial restrooms.
A urine receptacle that attaches to the conventional toilet is the solution to the aforementioned problems; it can minimize the distance between the discharging member of the male and the receptacle, it can make the lifting of the seat unnecessary, it can decrease the consumption of water, and it would not occupy much space. Currently, the only attachable urinals on the market are simple, waterless apparatuses such as the WeeMan Urinal, which is a simple plastic pouch gripping the rim, and the Main Drain as seen on Kickstarter, which is a receptacle with a semi-flexible tube gripping the rim of the toilet. U.S. Pat. No. 8,424,125 B2 of A. M. Anderson describes a urinal of this type, which is a receptacle with an extendable arm gripping the toilet seat. These simple apparatuses must be rinsed manually and are intrusive for people sitting on the toilet, unless removed prior to sitting.
Multiple rinsable urinals attachable to a toilet have been proposed, none of them reaching the current mainstream market. This may be attributed to several factors such as inconvenient operation, faulty designs, or difficult or costly manufacturing or installation procedures. For example, U.S. Pat. No. 4,137,579 of P. S. Soler and U.S. Pat. No. 5,737,779 of R. H. Haddock must be hand-held during use, and thus are inconvenient to use.
Proposals of faulty designs include U.S. Pat. No. 4,282,611 of G. L. O'Day, which describes an attachable urinal that guides liquid waste into the bowl. In the nonoperational position, the attachable urinal is pivoted to the side where water or liquid waste remaining in the urinal can drip or pour out of the device and onto the floor, thus defeating its purpose. U.S. Pat. No. 5,153,947 of E. C. Markles describes an attachable urinal that pivots from brackets attached to the toilet seat bolts, There is nothing to prevent the urinal from pivoting below a 0° incline, which would allow remaining liquid waste or rinsing water to spill out. To prevent this, the user would be required to inconveniently hold the receptacle in place during use. Also, his only self-cleaning embodiment shows the receptacle and waste tubes are clean-rinsed only when the toilet is flushed, thus over-consuming water. Furthermore for this embodiment to work, the height of the receptacle cannot be adjusted to reach the heights of different users, as the low water-pressure of the toilet bowl's filling line would not be able to reach a receptacle much higher than the toilet tank, U.S. Pat. No. 5,390,374 of S. E. Hubrig, et al describes an attachable urinal with the receptacle attached to a flexible arm, a waste line leading from the receptacle, down the arm, into the toilet bowl, through the water trap, and leading to the sewer. The flexible member is unlikely dependable to release during operation, and the waste line obstructs solid waste in the water-trap. U.S. Pat. No. 6,079,057 of P. M. Mette describes a free-standing urinal with a reservoir to retain liquid waste when in operation. Since the waste reservoir allows the user of several of his embodiments to pivot below a 0° incline, the receptacle would have to be so designed that the underlip reaches upward to prevent the remaining liquid waste or rinsing water from spilling out. However, this design would make it difficult for a tall user to urinate into the receptacle. The installation of this free-standing urinal would require bolting to the walls or floors for security, thus defacing the walls or floors and lowering the value of the bathroom. Furthermore, the reservoir could cause problems such as mildew, foul odor, and difficulty in manipulating the urinal with a full reservoir.
Proposals that would require difficult or costly manufacturing or installation procedures include U.S. Pat. No. 5,655,230 of J. H. Corbin, which describes an auxiliary urinal retrofit, a self-supporting urinal with its own water-tank mounted to a base-plate that is secured by extending the base-plate under the toilet or attached to the wall. This design would require more space than what most bathrooms currently possess, and the installation would require the difficult removal of the toilet. U.S. Patent Application 2012/0246816 A1 of S. Jung describes a rotatable urinal that requires a new toilet with a design alteration of the conventional toilet to accept the attachable urinal, further increasing the cost to the consumer.
SUMMARY OF THE INVENTION
The objective of this invention is to provide a waste-line system that guides liquid waste from close proximity to a user's discharging member to a pre-existing waste-receiver without requiring the lifting of the toilet seat. This waste-line system is supported by a structure that securely attaches to a conventional toilet or other fastened object in the toilet's immediate vicinity, takes preventative measures to avoid water or waste spillage, and is unobtrusive for toilet-sitters when placed in the nonoperational position. Furthermore, this waste-line system has a controllable water-line system for dispersing water and clean-rinsing the waste-line system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front-right perspective view of an embodiment of an adjustable urinal, which is attached to a conventional toilet in the first, upright, non-operational position.
FIG. 2 is a front-left perspective view of the embodiment of FIG. 1 , which is attached to a conventional toilet in the second, near-horizontal, operational position.
FIG. 3 is a front-right perspective view of a portion of the embodiment of FIG. 1 with a cone-like shaped receptacle and a section-cut of an arm for a view of the arm's interior.
FIG. 4 is a top-rear perspective view of the receptacle portion of the embodiment of FIG. 1 with a section-cut of the receptacle.
FIG. 5 is a left perspective view of the point of pivot portion of the embodiment of FIG. 1 with a section-cut of the arm and a leg.
FIG. 6 is a rear perspective view of the leg and point of pivot portion of the embodiment of FIG. 1 with a section-cut of the leg for a view of the leg's interior.
FIG. 7 is a rear perspective view of an alternate design of FIG. 6 with a section-cut of the leg to reveal an alternate design of attaching the wire to the axle of the arm.
FIG. 8 is a right-bottom perspective view of a portion of the embodiment of FIGS. 1 and 2 with a support-arm and outlet end of a waste tube.
FIG. 9 is a rear perspective view of a portion of the embodiment of FIGS. 1 and 2 with a foot and bottom portion of the leg.
FIG. 10 is a right perspective view of an alternate version of the foot of FIG. 9 .
FIG. 11 is a rear perspective view of another alternate version of the foot of FIG. 9 .
FIG. 12 is a front-right perspective of another embodiment of an attachable, adjustable urinal.
FIG. 13 is a front-right perspective view of a portion of the embodiment of FIG. 12 with a cone-like shaped receptacle and arm, the arm has a section-cut for a view of the arm's interior.
FIG. 14 is a top-rear perspective view of a portion of the embodiment of FIG. 12 with a section-cut of the receptacle.
FIG. 15 is a rear perspective view of a portion of the embodiment of FIG. 12 with the point of pivot where the bottom part of the arm meets the top portion of the leg, which has a section-cut for a view of the leg's interior.
FIG. 16 is a rear-right perspective view of the bottom of another embodiment of the urinal that features an alternate waste-expulsion design using a 3-way toilet-seal and toilet-base, and the bottom of the toilet, which is raised for demonstration.
FIG. 17 is a front perspective view of the embodiment of FIG. 15 (toilet is not shown); a waste tube is separated and moved to the left to view the toilet-base.
FIG. 18 is a rear perspective view of a leg and foot of the embodiment of FIG. 14 .
FIG. 19 is a front-left perspective view of an alternate foot design to FIG. 16 , which attaches to the toilet base.
FIG. 20 is a right perspective view of a slightly altered embodiment of FIG. 1 to show the bottom half of the arm with a counterweight.
FIG. 21 is a right-rear perspective view of an embodiment of an alternate rim.
FIG. 22 is a right-rear perspective view of a cross-section of the embodiment of the rim of FIG. 21 .
DETAILED DESCRIPTION
FIGS. 1 - 6 , 8 , 9 —First Embodiment
FIG. 1 shows an embodiment of an adjustable, attachable urinal as it would be mounted on a toilet 1 in the first, non-operational, upright position. The major structure of this embodiment and others later described consists of a receptacle 2 joined to a hollow, rigid arm 3 , which is mounted at the top of a hollow, cylindrical leg 4 at a point of pivot 5 . The leg 4 is held in place by a foot 6 a and a support-arm 7 , which are bolted to a closet bolt 8 and a toilet-seat bolt 9 , respectively.
FIG. 2 shows the embodiment of FIG. 1 in the second, operational, near-horizontal position. In this position, a water-spray 10 is released inside the receptacle 2 . The receptacle 2 connects to a waste tube 11 that leads through the hollow arm 3 and exits the arm 3 at the point of pivot 5 . The waste tube 11 then turns toward the toilet 1 , passes between the rim of the toilet bowl 13 and the toilet seat 14 , and turns into the toilet bowl 12 .
FIGS. 3, 4, 5, 6, 8, and 9 show different portions of embodiment of FIG. 1 . This embodiment includes a spring-powered mechanism for returning the arm 3 from the second position to the first position. FIGS. 3 and 4 feature the receptacle 2 and arm 3 . FIG. 3 is from a right perspective view with a cross-section of the arm 3 and FIG. 4 is from a top-rear perspective view with a cross-section of the receptacle 2 . Both FIGS. 3 and 4 show a water-inlet tube 15 , which is led through the arm 3 , along the receptacle 2 to water-sprayers 16 near the edge of the receptacle 2 , a rim 17 at the edge of the receptacle 2 , and a handle 18 joined to the receptacle 2 . A lever 44 is mounted to the handle 18 , which pulls on a wire 45 when pressed. The wire 45 and a wire-sleeve 46 leads through the arm 3 (the edge of the arm 3 is left out of the section-cut to demonstrate that the wire leads into the arm 3 ) to the point of pivot 5 . As shown in FIG. 3 , the waste tube 11 connects to the neck end of the receptacle 2 and runs through the hollow arm 3 alongside the water-inlet tube 15 and wire-sleeve 46 . FIG. 3 demonstrates how the rim 17 and edge of the receptacle 2 is curved so that the lower portion is slightly more extruded than the top.
FIG. 5 shows a left-perspective view of a cross-section of the arm 3 and leg 4 , and FIG. 6 shows a rear perspective view of the bottom part of the arm 3 and a cross-section of the leg 4 . Both FIGS. 5 and 6 show that a ratchet wheel 47 is held loosely in place by an axle 49 , which is joined to the two sides of the arm 3 that runs through the leg 4 at elongated holes 50 a and 50 b . A peg 47 a protruding from the ratchet wheel 47 runs through the leg 4 at elongated hole 50 c . The wire 45 is connected to the pawl 48 , which is held loosely in place by a rod 51 with a torsion spring (not shown) turning the pawl 48 toward the ratchet wheel 47 , and where the rod 51 connects to the arm 3 . A latch 52 is held in place by a rod 53 in the same fashion as the pawl 48 is held by the rod 51 with the rod 53 being connected to the arm 3 with a torsion spring (not shown) turning the latch 52 toward the pawl 48 . The ratchet wheel 47 has a protrusion that extends vertically in the rear, which has a protrusion 47 b that extends horizontally forward.
Furthermore, FIGS. 5 and 6 show that the sides at the end of the arm 3 at the point of pivot 5 is shaped elliptically 3 b and 3 c , the edges of which is resting on two wheels 54 a and 54 b . The valve stem 20 a attaches to one of these wheels 54 b . The other wheel 54 a is loosely fitted to an axle 21 a , which is joined to both the leg 4 and valve 19 a . FIG. 6 shows a compression spring 55 in which one end attaches to the base of the leg 4 a and the other end attaches to a wire 56 , which leads up the leg 4 , past the valve 19 a and valve stem 20 a , and fastens around the arm axle 49 . A pneumatic tube 57 is mounted to the two axles 49 (loosely) and 21 a.
FIG. 6 also shows a water-inlet tube 15 connected to the valve 19 a . The bottom side of the valve 19 a connects to another water-inlet tube 22 . This inlet tube 22 has a threaded end 23 for receiving a braided compression tube 24 (as shown in FIG. 2 ).
FIG. 8 shows an exploded, bottom-right view of the support-arm 7 , previously shown in FIGS. 1, 2, and 6 . The support-arm 7 is mounted to the leg 4 ( FIG. 1 ) by a lever-tightening clamp 24 that is joined at one end of the support-arm 7 . The support-arm 7 is shaped like a hollow bar with the middle part of the top-side removed. An extender-bar 25 slides into support arm 7 and a bolt 28 runs through both elongated holes 26 and 27 , which tightens the two bars together by a wing-nut 29 . The end of the extender-bar 25 on the opposite end of the clamp 24 has a hole 30 for fitting a contemporary toilet seat bolt 9 .
Furthermore, FIG. 8 shows that in the area where the waste tube 11 is about to end, the tube alters its shape 11 b from a cylindrical-like tube 11 a to a horizontal, rectangular-like tube 11 c , which leads between the toilet bowl rim 13 and toilet seat 14 ( FIG. 2 ), which is then bent downward and placed into the toilet bowl 12 ( FIG. 2 ). The bolt 28 holding the support-arm and extender-bar 25 together is affixed to the waste tube 11 between the shape alteration 11 b and the rectangular tube 11 c.
FIG. 9 shows a right perspective view of the foot 6 a and bottom portion of the leg 4 . The leg 4 is inserted at the top of the foot 6 a by a lever-tightening clamp 31 . The foot 6 a is curved and has a hole 32 for inserting the closet bolt 8 ( FIG. 1 ). A hole 33 in the foot 6 a allows the leg 4 to slide through the bottom of the foot 6 a.
Operation
FIGS. 1 - 6 , 8 , 9 —First Embodiment
The embodiment of this adjustable, attachable urinal was designed to be installed on a variety of conventional toilets 1 , on either side. Installation is as follows: the foot 6 a (detailed in FIG. 9 ) is set to sit on the lower base of the toilet 1 with the foot's hole 32 on the pre-existing closet bolt 8 . The hole 30 of the extender-bar 25 (detailed in FIG. 8 ) is placed on the toilet-seat bolt 9 , and the clamp 24 of the support-arm 7 is placed loosely around the leg 4 . The installer deposits leg 4 into the foot 6 a and decides on the height of the overall urinal, including whether it should be lowered to slip through the hole 33 at the bottom of the foot 6 a . The installer then tightens the clamp 31 of the foot 6 a , decides whether the urinal should be placed further back or to the side by rotating the urinal, and then tightens the closet-bolt 8 to the foot 6 a . The installer then slides the support-arm 7 to a height so that it is flush with the extender-bar 25 . The installer then manipulates the end of the tube 11 so that the bolt 28 affixed to the tube 11 at the shape alteration 11 b passes through both elongated holes of the support-arm 26 and the extender-bar 27 . The installer then tightens the wing-nut 29 onto the bolt 28 , tightens the toilet seat bolt 9 , and tightens the clamp 24 onto the leg 4 . To conclude, the installer fits a compression tube 24 from the pre-existing water outlet to the threads 23 of the water-inlet tube 22 . Should the owner ever decide to alter the overall height of the urinal, he would simply have to release the lever-clamp 24 , raise or lower the leg 4 to the desired height and retighten the lever-clamp 24 .
Once installed, there are two positions for the adjustable, attachable urinal. The first position is an upright, non-operational position as shown in FIG. 1 , and the second position is a near-horizontal, operational position as shown in FIG. 2 . In the first position, the arm 3 is upright, the valve 19 is closed, and no water flows into the receptacle 2 . As the operator maneuvers the arm 3 by pulling the handle 18 downward into the second position, the elliptical wheels 3 b and 3 c of the arm 3 turn and causes two events: the two wheels 54 a and 54 b to turn, and the arm 3 and all attached to rise.
As FIG. 6 illustrates, while one wheel 54 b regulates water flow, the other wheel 54 a and corresponding axle 21 a provides balance to the arm 3 and pivoting motion. The wheel 54 b is joined to the valve stem 20 so that as the wheel 54 b turns, so does the valve stem 20 , thus opening the valve 19 and releasing water from the water-inlet tube 22 into the water-inlet tube 15 to the water sprayers 16 , and into the receptacle 2 to rinse the interior (detailed in FIGS. 3 and 5 ). From the receptacle 2 , the water and/or waste is then funneled into the waste-tube 11 , and as FIG. 8 illustrates, the water is then funneled from the waste tube's cylindrical portion ha to the tube's alteration 11 b , and then to the rectangular tube 11 c , where it escapes into the toilet bowl 12 . The rectangular tube 11 c is designed to be thin in order to reach the toilet bowl 12 with the toilet seat 14 down by passing between the toilet rim 13 and the toilet seat 14 without the seat resting on and pinching the tube 11 c.
Referring to FIGS. 5 and 6 , as the elliptical wheels 3 b and 3 c turn, the distance between the centers and thus the axles of the ellipses 49 and the wheels 20 a / 21 a increase. The only allowance of this distance increase is for the axle of the ellipses 49 to rise in the elongated holes 50 a and 50 b of the leg 4 . As the axle 49 rises, so does the wire 56 wrapped around it, which in effect pulls on and stretches the compression spring 55 . If there is no resistance, the spring would pull the axle 49 , wire 56 , and arm 3 downward, causing the arm 3 to turn back to its upward position. However, the pawl 48 and ratchet wheel 47 offers such resistance. The ratchet wheel 47 is designed so that as it rises along with the arm 3 the wheel does not turn with the arm 3 : the ratchet wheel 47 is loosely fitted on the axle 49 and the peg 47 a is inserted an elongated hole 50 c of the leg 4 , thus preventing the ratchet wheel 47 from rotating. Also, as the arm 3 turns, the pawl 48 runs along the circumference of the ratchet wheel 47 to be caught in the lower teeth and catching the arm 3 along with it.
As the arm 3 turns to the second position, the operator may decide on the angle of the arm, and therefore the ultimate height of the receptacle 2 by deciding which tooth of the ratchet wheel 47 to catch on the pawl 48 (detailed in FIGS. 5 and 6 ). However, the minimal height of the receptacle 2 is determined by two properties: the length of the elongated holes 50 a and 50 b , which would prevent any further distance between the axles 49 and 20 a / 21 a , thus preventing any further turning of the ellipses 3 b and 3 c and arm 3 , and the length of the extrusion of the arm 3 a , which would collide with the leg 4 . The angle determining this minimal height is not to exceed below a 5° incline to prevent water spillage.
As illustrated in FIG. 2 and detailed in the exploded views of FIGS. 3 and 4 , the rim 17 prevents water from spilling straight down from the water-sprayers 16 and offers some protection from water spraying or spilling backward. The rim's 17 curvature offers an operator a view and an access for manipulation.
To return this embodiment to the first position, the operator simply squeezes the lever 44 (detailed in FIG. 3 ), The lever 44 pulls the wire 45 , which pulls one end of the pawl 48 (detailed in FIGS. 5 and 6 ) in order to rotate away from the ratchet wheel 47 . This allows the compression spring 55 to compress since the previously mentioned resistance is now eliminated, now causing the arm 3 to return to its first position. To keep the pawl 48 away from the ratchet wheel 47 during the position change, the pawl 48 hooks onto the latch 52 when it is rotated from the lever 44 squeeze. Once the arm 3 is back in the first position, the latch 52 is pushed on the opposite side by the ratchet wheel's forward protrusion 47 b , causing the latch 52 to rotate and release the pawl 48 while ready to be caught on the ratchet wheel 47 , once again. The wire 45 is covered by a sleeve 46 to guide the wire 45 and prevent the sleeve 46 from catching. The pneumatic tube 57 mounted to the two axles 49 (loosely) and 21 a slows the distance between them, thus hindering acceleration and the rapid or jerky movement of the arm 3 in its rotation, and consequently acts as a cushioning for said arm, preventing any potential damage to or shifting of the urinal.
Detailed Description
FIGS. 8 , 9 , 12 - 15 —Second Embodiment
FIGS. 8, 9, 12, 13, 14, and 15 show another embodiment of the attachment urinal. FIG. 12 shows a full, right perspective view of this embodiment. The second embodiment is similar to the first as the second replicates the designs of the parts of FIGS. 8 and 9 , differing by altering the design of the water-inlet system somewhat and excluding the spring-return mechanism, which comprises of: the elliptical wheels 3 b and 3 c , the wheels 54 a and 54 b and their respective axles 49 , 21 a and 21 b , the spring 55 and attached wire 56 , the pneumatic tube 57 , and the elongated holes of the leg 4 - 50 a , 50 b , and 50 c.
As seen in both FIGS. 13 and 14 ( FIG. 13 is a front-right perspective view, FIG. 14 is a top-rear perspective view) and compared to FIGS. 3 and 4 , the lever 44 is eliminated. In FIG. 13 (when compared to FIG. 3 ), the wire 45 and wire-sleeve 46 is eliminated so that only the waste-tube 11 and water-inlet 15 travel inside the hollow of the arm 3 .
FIG. 15 is a rear perspective view featuring the point of pivot 5 , which is a lower portion of the arm 3 and a cross-section of the top portion of the leg 4 . Compared to FIG. 6 , the parts of the spring-return mechanism (mentioned previously) have all been eliminated. Instead, the arm 3 is joined to a valve stem 20 and loosely attached to an axle 21 . The valve stem 20 goes through a hole in the top of the leg 4 and enters a valve 19 . The axle 21 is joined to the leg 4 on the opposite end. The valve 19 is held in place by the leg 4 . The water-inlet tube 22 connects to the valve 19 from the bottom and the water-inlet tube 15 connects to the valve 19 from the top and continues through the arm 3 as it does in the first embodiment.
Operation
FIGS. 16 - 18 —Second Embodiment
The installation of the second embodiment is exactly the same as the first. The operation is similar with these few exceptions: When an operator pulls the arm 3 down by the handle 18 from the first position to the second, the arm 3 directly turns the valve stem 20 with an axle 21 on the opposite side to provide balance and support. The arm 3 is then either held in place or dropped to the minimal height as determined by the arm extrusion 3 a . To return the urinal to the first position, the operator lifts the arm 3 by the handle 18 and pushes the arm 3 back into place.
Detailed Description
FIGS. 16 - 18 —Third Embodiment
FIGS. 16 and 17 show a rear-right and front-top perspective view, respectively, of a third embodiment of the urinal in order to demonstrate an alternate method of waste disposal. Instead of the waste tube 11 leading into the toilet bowl 12 as shown in the first and second embodiments, the waste tube 11 leads to a unique 3-way toilet seal 36 . This 3-way toilet seal 36 is much like a conventional rubber/plastic toilet seal 36 a that connects a toilet sewer line 39 and the sewage outlet of the toilet 1 , except that a flat tube 36 b protrudes from one side of the toilet seal 36 a . The flat tube 36 b extends horizontally, turns upward, and alters in shape to become a cylindrical tube 36 c , which receives a 1-way backflow valve 37 with a ring clamp 40 to fasten the connection.
To allow the 3-way toilet seal 36 to extend out the rear of the toilet 1 so that the toilet 1 does not sit on the flat tube 36 b , a toilet base 38 is placed under the toilet leaving a gap in the back for the flat tube 36 b to escape. The base 38 is also used as a mount for the foot 6 a.
As the embodiment demonstrates in FIGS. 16 and 17 , and exclusively in FIG. 18 , the support-arm 7 clamps to the leg 4 , the extender-bar 25 bolts to the toilet seat bolt 9 , and a rod 41 enters the elongated hole 24 of the support arm 7 and a hole in the extender-bar 25 . Wing nuts 42 a and 42 b fasten the rod 41 to the support arm 7 and wing nuts 42 c and 42 d fasten the rod 41 to the extender-bar 25 . The bottom end of the rod 41 joins the foot 6 a.
Operation
FIGS. 16 - 18 —Third Embodiment
This third embodiment of the adjustable, attachable urinal was also designed to be installed on a variety of conventional toilets 1 , on either side. Installation is as follows (refer to FIGS. 16-18 ): if the toilet 1 is already installed, the toilet 1 must be removed from its location above the toilet sewer-line 39 . The installer centers the toilet-base 38 on the sewer-line 39 . The installer then pastes the 3-way toilet seal 36 a under the toilet on the sewage outlet with the flat tube 36 b running toward the rear of the toilet 1 . The toilet 1 is then placed over the toilet base 38 , fitting the 3-way toilet seal 36 a into the toilet sewer-line 39 . The 1-way backflow valve 37 is then inserted in the cylindrical end of the 3-way toilet seal 36 c and the clamp 40 is tightened around the connection. The extender-bar 25 is then placed on the toilet seat bolt 9 in the same manner described as in the first embodiment. The foot is then placed on a bolt (not shown) on the toilet base 38 , the position of the urinal is then decided on by its allowable rotation, and both bolts (seat bolt 9 and toilet base 38 bolt) are tightened, as well as the wing nuts 42 a and 42 b on the rod 41 . The installer determines the leg's 4 height and the foot's 6 a clamp 31 is tightened. The installer determines the height for the support-arm 7 so as not to conflict with any other parts. The installer then tightens the clamp 24 of the support-arm 7 , and tightens the wing nuts 42 c and 42 d on the rod 41 to the support-arm 7 .
This third embodiment is placed between the first and second positions and operates mechanically in exactly the same way as described in the first embodiment. However, instead of the water flowing through the waste tube 11 to the rectangular waste tube 11 a , 11 b , and 11 c and into the toilet bowl 12 , the water flows through the waste tube 11 to the backflow valve 37 , and into the 3-way toilet seal 36 . The purpose of the backflow valve 37 is to block noxious odors from escaping or inhibiting potential backflow from the sewer line.
Alternative Embodiments
FIGS. 7 , 10 , 11 , 19 - 22
There are various alternative designs to portions of the different embodiments:
As shown in FIG. 7 , the first embodiment can be slightly altered by mounting and wrapping the wire 56 around a disc 58 , which is joined to the axle 49 . As the arm 3 is turned downward, the axle 49 and disc 58 rotate, the wire 56 is pulled further, extending the spring 55 further. When the latch 52 is released and the spring 55 actuates, the wire 56 turns and pulls down the disc 58 , thus turning and pulling down the axle 49 and attached arm 3 , thus returning the arm 3 back to the first position.
FIGS. 10 and 11 show two different alternate designs of the foot 6 a of the first and second embodiments. FIG. 10 shows a right perspective view of a foot 6 b with a horizontal bar 34 along the bottom. FIG. 11 shows a rear perspective view of a foot 6 c with a bar 35 on the bottom to be wedged under the toilet 1 ( FIG. 1 ).
FIG. 19 shows a front-left perspective view of an alternate design for the leg 4 , as demonstrated in FIGS. 16-18 of the third embodiment. This design shows two feet 6 a and 43 mounted to the toilet base 38 . The second foot 42 is curved differently than the first foot 6 a so that the top end reaches higher on the leg 4 . This second foot 42 is intended to provide support and thus eliminates the support-arm 7 , extender-bar 25 , and rod 41 .
FIG. 20 shows a right perspective view of a slight alteration to the first and third embodiments in which a weight 59 is added to the elliptical ends 3 b and 3 c of the arm 3 by extensions 3 d and 3 e . This provides a counterweight to the arm 3 and makes the return from the second position to the first easier. The extensions 3 d and 3 e are joined to the exterior surface of the ellipses 3 b and 3 c so that when the arm is in its first position and the weight 59 is down, the extensions 3 d and 3 e go over the wheels 54 a and 54 b and do not obstruct contact between the wheels 54 a and 54 b and the ellipses 3 b and 3 c.
FIGS. 21 and 22 show a rear-left perspective view of a rim 17 a , which is a slightly altered design of the rim 17 of all three embodiments. FIG. 21 shows the rim 17 a in its entirety and FIG. 22 is a cross-section view of the front half of the rim 17 a . The rim 17 a contains two reservoirs 17 y and 17 z . A water-inlet tube 15 ( FIG. 4 ) is affixed to a hole 17 b of the first reservoir 17 y . The reservoir 17 y has only one outlet, a hole 17 c ( FIG. 20 ), which leads to the second reservoir 17 z . FIG. 19 shows the outlet of the second reservoir 17 z , which consists of little holes 17 d along the edge of the rim 17 a.
As the urinal is in the second position, the first reservoir 17 y fills with water from the water-inlet tube 15 . If the water level reaches the hole 17 c , the water spills into the second reservoir 17 z and trickles through the lower little holes 17 d . When the urinal is returned to the first position, the water empties out of the first reservoir 17 y into the second 17 z , and disperses out of the little holes 17 d to rinse the interior surface of the receptacle 2 .
CONCLUSIONS, RAMIFICATIONS, AND SCOPE
The reader will see that each embodiment described above achieves the main goals of the invention, that is, to provide a urinal that is structurally rigid, self-cleaning, attachable to most conventional toilets without attaching the urinal to the surrounding floor or walls (which would require serious carpentry work), adjustable to the users' preference or space limitations, unobtrusive in non-operative mode, and user-friendly. The urinal is user-friendly in the sense that it is easy to switch between non-operative and operative mode, and can be held in place hands-free during use.
The reader will also see that each embodiment also has its own advantages and disadvantages. While the first and second embodiments are easier to install, the third allows the height of the receptacle to be lowered further to allow usage by shorter adults or children. The first embodiment requires little labor to return the urinal to the first position and is easy for multiple users to set the receptacle at different preferred heights. The second embodiment's simple design has fewer parts, which would mean that the production and manufacture is less expensive and potential mechanical problems would arise less often. Unless the user decides to flush the toilet after using the first or second embodiment, these two embodiments consume less water than using the toilet alone. The third embodiment, in bypassing the toilet, makes flushing completely unnecessary and guarantees water-saving. Unless the leg 4 pokes through the hole 33 of the foot 6 a all the way down to the floor of any of the three embodiments, or the feet 6 b or 6 c of FIGS. 10 and 11 are used, sweeping or mopping the floor under these embodiments is not very difficult.
As for the embodiments' materials, most parts can be made of a stain-resistant plastic, using the plastic molding injection process. It is recommended that parts undergoing stress or friction, such as the axles 20 , 21 , 20 a , 21 a , 49 , parts of the spring return mechanism, valves 19 , 19 a , support arm 7 , or extender-bar 25 , be made of metallic materials with high oxidation-resistance, such as aluminum, brass, or stainless-steel.
While my above descriptions contain many specifics, they should not be construed as limitations on the scope, but rather as an exemplification of several embodiments thereof. Many other variations are possible. For example, instead of the third embodiment having the same spring-release mechanism described in the first embodiment, an alternative design can eliminate this mechanism and incorporate the second embodiment's simplified form. Another variation can switch out the foot, leg, support-arm, extender-bar and rod design featured in FIG. 18 for the foot, leg, support-arm, and extender bar design of the first and second embodiments. Only in this variation, the receptacle will be limited to the same minimal height as the first and second embodiments since the point of pivot 5 cannot exceed below the toilet bowl rim 13 .
Additionally, many parts of these embodiments can be slightly altered or substituted with other parts that perform the same function. For example, the handle 18 can be altered to include a grip to the left and/or top of the receptacle 2 . The lever-tightening clamps 24 and 31 can be regular nut and bolt ring-clamps. The leg 4 can be separated and mounted together loosely just below the valve to allow the top portion to pivot horizontally slightly when the arm 3 is in the second position. The pneumatic tube 57 may be a hydraulic tube.
The valves 19 and 19 a can be any turn-based valve; a compression-valve, ball valve, cartridge valve, etc. An alternative to the turn-based valve is one actuated by the pulling or pushing of a rod such as an equilibrium valve. This type of valve can be placed in the same position in the first and third embodiments with the end of the valve stem loosely mounted to the axle 49 . The valve can be placed in the second embodiment and designed so that the valve stem is loosely mounted to the arm 3 and is opened and closed by the movement of the arm 3 . Furthermore, the valve stem can be loosely mounted to a peg near the circumference of a disc (similar to the one in FIG. 7 ) on an axle that is a combination of the axles 20 and 21 .
A valve in addition to, or in replacement of, the valves 19 , 19 a can be placed around the receptacle 2 or arm 3 to allow greater control of water flow during operation and/or anywhere along the water-inlet tube 22 for a pre-determined water flow.
The valve of any of the embodiments can be also altered to be timer-based, either mechanical or electrical. The return of the arm 3 to the first position would cause the beginning of the count-down of the valve's opening. Using the rim 17 a of FIG. 21 , the water would disperse evenly down the waste-tube 11 in the first position until the end of the timer, at which point the valve closes.
For the embodiments in which the extender-bar 25 is mounted to the toilet-seat bolt 9 , a thick nylon washer can be placed on the other seat bolt to balance the toilet seat. In cases where there is not enough room to run the rectangular waste tube 11 c between the toilet bowl rim 13 and toilet seat 14 , one or two more washers can be placed on both seat bolts to raise the seat just enough to slip the tube 11 c through without the toilet seat 14 sitting on and pinching the tube 11 .
FIG. 8 shows how a nut 29 is tightened to hold the waste tube 11 in place during installation. Alternatively, another nut and bolt (not affixed to anything) can be used to hold together the support-arm 7 and extender-bar 25 , allowing the bolt 28 affixed to the waste tube 11 to be bolted to either the support-arm 7 or the extender-bar 25 , depending on the shape of the toilet bowl rim. FIG. 8 also shows how the extender-bar 25 can slide into the support-arm 7 . However, the support-arm 7 can alternatively be bar-shaped, like the extender-bar 25 , so that the two can form an angle and so the different embodiments of the urinal can be placed further behind the toilet 1 during installation.
For the embodiments that incorporate the elliptical wheels 3 b and 3 c and their complementary circular wheels 54 a and 54 b , these wheels can have a surface material that increases the wheels' friction, or they can be redesigned as complementary gears in order to ensure that the turning of the elliptical wheels turn the circular wheels, which ensures that the valve 19 a opens and closes correctly. Also, these wheels can be dissected so that the only part of the circumference that remains is the part that touches the other wheel and the area that keeps the structural integrity between the circumference and the part joined to the arm 3 (ellipse) or axles 20 a and 21 a (circle).
For the second embodiment, it is not easy for multiple users to drop the receptacle to different preferred heights. This inconvenience can be resolved by having the arm extrusion 3 a adjustable lengthwise using a sliding bar in order to reset the minimal angle incline of the arm 3 , and therefore the minimal drop-down height of the receptacle 2 .
As an alternative to the spring-return mechanism of the first and third embodiments, a motor can be included in the second embodiment, either placed at the point of pivot 5 to directly turn the axle 20 , 21 , or arm 3 , or placed elsewhere and using an intermediary, such as a belt or chain, to turn the axle 20 , 21 , or arm 3 .
Another alternative to the spring-return mechanism is to incorporate into the second embodiment a torsion spring, one end joined to the leg, the other to the arm, at the point of pivot 5 to return the arm 3 from the second position to the first. Furthermore, a ratchet wheel, pawl, latch, wire, and lever of the first embodiment can be included in this alteration in order to prevent the arm 3 from returning prematurely and to determine the angle of the arm 3 and ultimate height of the receptacle.
To simplify the spring-return mechanism of the first and third embodiments, the ratchet wheel 47 and pawl 48 can be removed, and the latch 52 can be spring-hinged at the top of the leg 4 . The latch 52 can be placed to catch the axle 49 of the arm 3 when the arm 3 is turned to the second position and the axle 49 concurrently rises. Pulling the lever 44 and wire 45 turns the latch 52 and releases the axle 49 , thus allowing the spring to pull the axle 49 down and return the arm 3 .
Likewise, the latch 52 can be moved or duplicated to be spring-hinged just under the hole 50 a to catch the axle 49 as it is in its lowest position, when the arm 3 is in its first position. This will prevent the arm 3 from falling undesirably. For release, a lever can be attached to the handle under the receptacle 2 , with a complementary wire and wire-sleeve leading to the new latch.
The third embodiment features a 1-way backflow valve 37 as a method of blocking noxious odors of the sewer-line or inhibiting backflow. As an alternative, a P water-trap can be placed between the waste-tube 11 and 3-way toilet seal 36 , or somewhere along the waste tube 11 in order to block the noxious odors. The only outlet for backflow would be the receptacle 2 , which is far above the rim of the toilet in the first position, and therefore unlikely any backflow would discharge from the urinal.
FIGS. 10 and 11 show alternative feet for the first and second embodiments. If necessary, the feet can be further secured by adding another bar, like the arm support 7 . One side of the bar clamps low on the foot 6 b or 6 c and the bar's opposite side is bolted down by the closet bolt 8 .
The design of the counterweight of FIG. 20 can be incorporated into the second embodiment.
The alternative rim 17 a featured in FIGS. 21 and 22 can be further altered to include the handle 18 (hollowed out) as part of the first reservoir 17 y.
The previous description and figures demonstrate embodiments that are designed to attach to the conventional toilet 1 . However, the toilet itself can be redesigned to accept and secure the different embodiments. A hole or holder can be placed beside the toilet seat bolts 9 (on either side) or lower beside the toilet bowl 12 to receive the leg 4 of the different embodiments. The hole can lead into the top of the toilet bowl 12 so that the waste-tube 11 leads through the leg 4 and directly into the toilet bowl 12 . The toilet can also be redesigned to have a second, smaller water-trap running beside the current one, the inlet designed to be somewhere accessible for receiving the waste-tube 11 such as the rear or on the toilet rim 13 in the area by the toilet seat bolts 9 , thus making the 3-way toilet seal 36 and toilet base 38 unnecessary in order to bypass the toilet bowl 12 .
Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.
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A universal, attachable urinal. Urine is discharged into receptacle ( 2 ) that funnels to a waste-tube ( 11 ) that runs through a hollow arm ( 3 ) to a pre-existing waste receiver. The arm ( 3 ), mounted by the receptacle ( 2 ), pivots on a stationary leg ( 4 ) between an operational and a nonoperational position. The leg ( 4 ) is secured next to the toilet by foot ( 6 a ) and/or support arm ( 7 ), using the closet bolt ( 8 ), toilet seat bolt ( 9 ), or other nearby secured object. A water line runs from the toilet's water source to the receptacle ( 2 ) for rinsing it and the conjoined waste-tube ( 11 ). Embodiments vary between the waste-tube ( 11 ) leading to the toilet bowl ( 12 ) or sewer-line ( 39 ), the manual or semi-automatic upright return of the arm ( 3 ), methods for securing the leg ( 4 ), and methods for controlling water dispersion to and in the receptacle ( 2 ) for rinsing.
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BACKGROUND OF THE INVENTION
[0001] (1) Field of the Invention
[0002] This invention relates to a docking system for handheld electronic communication devices such as cellular telephones or the like, for use with structures or vehicles, and is a Continuation-In-Part Application of U.S. patent application Ser. No. 08/581,065, filed Dec. 29, 1995, which is a Continuation-In-Part Application of our allowed co-pending U.S. patent application Ser. No. 08/042,879, filed Apr. 5, 1993, each being incorporated herein by reference, in their entirety.
[0003] (2) Prior Art
[0004] Extraneous radio frequency emission has become a serious concern of hand-held electronic communication devices such as portable facsimile machines, ground position indicators, and cellular telephone manufacturers and users alike. RF radiation is considered a potential carcinogen.
[0005] The proliferation of these hand-held devices is evident everywhere. A single hand-held device however, should able to travel with its owner and be easily transferably usable in automobiles, planes, cabs or buildings (including hospitals) as well as at offices and at desks with no restrictions on their use, and without causing concern with regard to the radiation therefrom. The hand-held devices should be portable for a user to carry in his pocket, yet be able to use that same cellular unit in such vehicle or building while minimizing such radiational effect therein.
[0006] It is an object of the present invention to permit a user of a portable hand-held electronic communication device such as a cellular telephone or the like, to conveniently use that same hand-held device/cellular phone in an automobile, plane or building, office/desk, or anywhere signal transmission is needed, and to permit such signal to reach its intended destination such as a communications network or satellite, without interfering with other electrical equipment and in spite of interfering walls of buildings or structure and/or other electrical equipment.
[0007] It is a further object of the present invention to minimize any radiation from such a portable device, such as a cellular telephone or the like, while such use occurs in an automobile, a building or an elevator, an airplane, a cab, or other public facility in which the user wishes to minimize his own exposure to stray radiation, and also to permit re-transmission of his signal, to avoid the necessity of connecting and disconnecting cables, and to permit a wide variety of cellular telephones such as would be utilized in a rental car where various manufactures' phones would be used, and to permit control of such re-transmission of signals where desired, so as to allow user/customer billing and monitoring thereof.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention comprises a docking system adaptable to an automobile, plane, building or desk for receipt of an electronic communication device such as a cellular telephone, portable computer, facsimile machine, pager or the like, to permit a user safe, environmentally safe, non-touching, radiationally communicative mating of the antenna of that device to a further transmission line through a juxtaposed pick-up probe, the signal coming in or going out through a communications network or further remote antenna.
[0009] The docking system may comprise a “zone” or “focal area” as a generally rectilinear area/volume on/in a desk or work surface on/in which the electronic communication device may be placed, such a surface or space being possible on a desk, or in a plane. That focal area may also, in a further embodiment, be comprised of one or more rooms in a building, such focal area having a pick-up probe thereat, in conjunction with a shield placed on/in the desk, room, vehicle or building to prevent the radiation from that communication device from traveling in any undesired directions within the desk, room, vehicle or building.
[0010] The focal area may be defined by a metal walled structure within or on which a broadband probe is arranged. The metal walled structure acts as a shield to minimize radiation from the communication device from passing therethrough. In a first embodiment, the shield may be comprised of a partial housing disposed within the upper work surface of a desk. The probe would be elongatively disposed within the partial housing and be in electrical communication with a transmission line such as coax cable, waveguide, or the like. The partial housing may have a planar dielectric layer thereover, which would also be co-planar with the surface of the desk. The communication device would be placed within the pickup zone of the focal area, and would be able to transmit and receive signals through the dielectric layer. The partial housing would act as the shield in the desk, to minimize radiation by the worker at the desk. In a further embodiment, the housing may be comprised of a thin, generally planar mat of conductive material, which mat may be flexible and distortable, for conformance to a particular work surface and for ease of storage capabilities. The mat has an upper layer of dielectric material (for example, plastic, foam or the like). A thin, flat, conformable coupling probe may be embedded into or printed onto the upper surface of the dielectric material. The mat may be utilized as a portable focal area for placement of a communication device thereon, or wrapped up in an enveloping manner therein.
[0011] A yet further embodiment of the present invention includes a control unit in the transmission line from the pickup probe to the further remote antenna. The control unit may comprise a filter or switch connected to a computer. The computer may accumulate billing information, control system functions, or act as a regulator for multiple users of the antenna coupling system.
[0012] The invention thus comprises a docking system for connecting a portable communication device to a further signal transmission line, the portable communication device having an externally radiative antenna, the system comprising a shield for restricting at least a portion of any radiation from the externally radiative antenna of said portable communication device, and a coupling probe mounted adjacent to the shield for radiatively coupling between the externally radiative antenna of the portable communication device and the further signal transmission line via radio frequency energy therebetween. The shield may be comprised of an electrically conductive material, or an attenuative material capable of blocking at least part of the radiofrequency radiation energy coming from the communication device(s) connected thereto. The shield defines a focal area for receipt and transmission of a radio frequency signal, when a communication device is placed within the focal area. The focal area or zone, may be selected from the group of structures consisting of a desk, a room in a building, or a tray or the like in a vehicle. The further signal transmission line may be connected to a further communication network and/or a further antenna connected to the transmission line, yet positioned at a location remote from the shield. The transmission line may have a control unit therein, the control unit being arranged to permit regulation of signals being transmitted through the transmission line. The control unit may comprise a computer arranged to monitor time or use of the docking system. The shield and the probe may be spaced apart by a dielectric material. The shield, the probe and the dielectric material may be flexible. The communication device may include at least two cellular telephones (or other portable communication devices) simultaneously connected to the remote antenna.
[0013] The invention also includes a method of coupling a portable communication device having an externally radiative antenna, to a signal transmission line having a further remote antenna thereon, for the purpose of effecting radio signal transmission therebetween, the method comprising the steps of arranging a radiation shield in juxtaposition with at least a portion of said radiative antenna of the portable communication device, mounting a coupling probe adjacent the shield and in communication with the signal transmission line, and placing the externally radiative antenna of the portable communication device close to the probe and the shield so as to permit radiative communication between the externally radiative antenna and the signal transmission line via the coupling probe. The method may include arranging the shield in or on a generally planar work surface so as to restrict the propagation of at least a portion of the radiation emanating from the communication device primarily only to the vicinity of the probe. The method may include attaching a control unit to the transmission line to permit regulation of electric signals therethrough, and adding a further communication device in juxtaposition with a further probe, the further probe also being in electronic communication with that control unit, so as to permit multiple simultaneous use of the transmission line and communication system and/or remote antenna therewith. The method of coupling the portable communication device to the signal transmission line, may also include the step of billing any users of the communication and/or remote antenna by monitoring and tabulating any signals received by and sent through the control unit.
[0014] It is an object of the present invention to provide a shielded antenna docking arrangement, which itself may be portable, for use with a portable communication device such as a cellular telephone, facsimile machine or ground position indicator or the like, such use occurring in a vehicle such as a plane, an automobile or a cab or in a public or private building, office desk or elevator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The objects and advantages of the present invention will become more apparent when viewed in conjunction with the following drawings in which:
[0016] FIG. 1 a is a perspective view of a focal area docking arrangement, as may be utilized with a desk;
[0017] FIG. 1 b is a partial view taken along the lines A-A of FIG. 1 a;
[0018] FIG. 2 a is a perspective view of a portable focal area docking system for portable communication devices;
[0019] FIG. 2 b is a view taken along the lines B-B of FIG. 2 a;
[0020] FIG. 3 a is a block diagram of a docking system having a sensor unit arranged therewith;
[0021] FIG. 3 b is a block diagram of a further embodiment of that shown in FIG. 3 a ; and
[0022] FIG. 4 is a side elevational view of a docking system, as it may be utilized in a vehicle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Referring now to the drawings in detail, and particularly to FIG. 1 a, there is shown a portable communication device docking arrangement 10 , to permit a portable communication device such as a hand-held cellular telephone 12 to be utilized thereon, such as on a desk 14 or adjacent to it, and as a personal communicator (i.e. cellular telephone, facsimile machine, pager or the like) which may also be carried on an individual.
[0024] Such a docking system 10 of the present invention may also be adaptable to an automobile, plane, or building for providing radiationally restrictive communication between a portable electronic communication device 12 such as a cellular telephone, portable computer, facsimile machine, pager, or the like, while allowing communicative mating of the radiative antenna of that device to a further transmission line and communication system and/or a more remote antenna, as recited and shown in our aforementioned patent applications, incorporated herein by reference in their entirety.
[0025] The docking system 10 may comprise a “zone” or “focal area” 16 as a rectilinear area/volume on/in a desk 14 or work surface on/in which the electronic communication device 12 may be placed, such a surface or space being in a structure such as an airplane. That focal area 16 has a pick-up coupling probe 22 thereat, as shown for example in FIG. 1 b, in conjunction with a shield 24 placed on/in the desk 14 , (or room, vehicle or building, as shown in FIGS. 3 a and 3 b ), to prevent the radiation (electromagnetic/microwave) emanating from that communication device 12 from traveling in any undesired directions within the desk, room, vehicle or building.
[0026] The focal area 16 may be defined by a metal walled housing structure 30 within which a broadband probe 22 is arranged, as shown in FIG. 1 b. The metal walled structure 30 acts as a shield to minimize undesired radiation from the communication device 12 from passing therethrough. In a first embodiment, the shield may be comprised of a partial housing 34 disposed within the upper work surface 36 of a desk 14 , as may be seen in FIG. 1 b. The pick-up probe 22 would be elongatively disposed within the partial housing structure 30 and be in electrical communication with a transmission line 32 such as coaxial cable, waveguide, or the like. The transmission line 32 would be in electrical communication with an electric communications network or distribution system 38 , and/or to a further remote antenna 40 , such as may be seen in FIGS. 1 b, 3 a and 3 b. The partial housing 30 may have a planar dielectric layer 42 thereover, which would also be co-planar with the surface of the desk 14 . The communication device 12 would be placed within the pickup zone of the focal area 16 , and would be able to transmit and receive signals through the dielectric layer 42 . The partial housing 30 would act as the shield in the desk, to minimize radiation directed towards the worker(s) at the desk.
[0027] In a further embodiment as shown in FIG. 2 a , the shield or housing may be comprised of a thin, generally planar mat 50 of conductive material, which mat 50 may be flexible and distortable, for conformance to any surface (human or otherwise), and may be folded or rolled up to minimize storage requirements. The mat 50 has an upper layer 52 made of a dielectric material (plastic, foam or the like). A thin, flat, conformable coupling probe 54 is embedded into or printed onto the upper surface of the layer of dielectric material 52 . The mat 50 may be utilized as a portable focal area for placement of a communication device thereon, or wrapped-up in an enveloping manner therein. The probe 54 is connected to a transmission line 56 , in electrical contact with a network or remote antenna, not shown in this figure.
[0028] A yet further embodiment of the present invention includes a control unit 60 , connected into the transmission line 62 from the pickup probe 64 to the further remote antenna 66 shown in FIGS. 3 a and 3 b . The control unit 60 may comprise a filter, switch, amplifier, attenuator, combiner, splitter, or other type of frequency converter, connected to a computer 68 . The computer 68 may be arranged to accumulate customer or billing information by functioning with a processor to print out use-data 69 , to maintain frequency control functions, or to act as a regulator for multiple users of the antenna coupling system 10 . There may be a plurality of pickup coupling probes 64 each connected to the control unit 60 and the transmission line 62 , one probe 64 in each of a plurality of shielded rooms 65 , each wall or work area (desk) having a shield, the rooms 65 shown in a building 67 , in FIG. 3 b.
[0029] The view shown in FIG. 4 , displays a portable communication device such as a facsimile machine or computer 70 supported on a tray 72 articulably mounted on the back of an airplane seat 74 . The tray 72 has a “focal area” 75 therewithin, as represented by the dashed lines 76 . The focal area 75 includes a conductive (preferably metallic) shield arranged beneath and partially surrounding a broadband probe 77 . The probe 77 transmits electrical signals radiated to and from a radiative antenna on or in the base of the portable communication device 70 . A transmission line 78 which may be comprised of coaxial cable, waveguide, or optical fibers, extends from the probe within the focal area, to a further remote antenna 80 mounted outside of the structure, which here, is identified as an airplane.
[0030] A control unit 82 , such as attenuators, heterodyne converters, amplifiers, bandpass filters, switches, or the like, may be arranged in communication with the transmission line 78 to monitor or control the time in the vehicle in which the communication device may be utilized, for example, to limit certain times when such devices may be utilized in an airplane, or to modulate the signal being transmitted or received by the remote antenna, and/or to monitor usage of the docking system for subsequent billing of those users.
[0031] Thus what has been shown is a unique system for minimizing the detrimental effects of radiation from common portable communication devices to their users, while improving the transmission capabilities and customer usage of such devices, overcoming the barriers such as buildings and vehicles in which such devices might otherwise be utilized, that would interfere with the flow of signals transmitted.
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The present invention comprises a docking system for connecting a portable communication device to a further signal transmission line. The docking system may be arranged within a workstation such as a desk or a tray. The system may also envelope a room in a building or be located in a vehicle, to control and restrict the radiative emission from the communication device and to direct such radiation to a further remote antenna and or signal distribution system connected to the transmission line.
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BACKGROUND OF THE INVENTION
This invention relates generally to a safety valve for use in a hydraulic line system which prevents flow of a working hydraulic fluid above a specific flow rate and more particularly to a safety valve which is located in the barrel of a chute lift cylinder of a ready mix concrete truck.
The delivery chute on the rear of ready mix concrete trucks is conventionally raised and lowered by means of a hydraulic cylinder. In normal operating use, the chute is often full of concrete and held in position by a hydraulic cylinder. The hydraulic hose connected to the hydraulic cylinder is subject to wear, damage, and deterioration by the nature of its application. Frequent inspections for cuts, abrasions, wear, acid wash damage, etc., are necessary to prevent hose failure during operation. Failure may occur if the hose is not regularly inspected. Failure also results from damage occurring on the job site. Workers tugging and pulling on a heavy, full concrete chute can cause pressure spikes in the hydraulic fluid flowing through the chute lift hydraulic hose. Workers can also use the hydraulic hose connection to the cylinder as a hand hold which causes further damage and wear to the hose and connection. Previously damaged hoses may break from the pressure spikes in the chute lift hydraulic hose. A broken hose results in a sudden pressure loss and the fluid flow is no longer controlled. The sudden loss of pressure results in hydraulic fluid rapidly flowing from the hydraulic cylinder, resulting in the chute crashing downward and potentially seriously injuring workers.
What is needed is a way to prevent the chute from crashing downward due to a sudden loss of hydraulic fluid pressure.
SUMMARY OF THE INVENTION
The present invention is a safety valve which prevents the chute from rapidly falling due to a sudden loss of hydraulic fluid pressure. The safety valve is located in the interior of the chute lift hydraulic cylinder. The cylinder mount is drilled and tapped to provide for the safety valve located in the cylinder's barrel and the cylinder's port located in the cylinder mount. Normal hydraulic fluid flow coming out of the chute lift cylinder is less than three gallons per minute. The gallons per minute flow increases dramatically should the hydraulic hose break. The safety valve is activated any time the flow leaving the chute lift cylinder exceeds a predetermined value, e.g., approximately four gallons per minute. The safety valve immediately blocks further hydraulic fluid from leaving the chute lift cylinder and, thus, the chute cannot fall.
The principle object of this invention is to provide an internal safety valve to prevent the rapid falling of a hydraulically held concrete chute due to sudden loss of hydraulic pressure because of a hydraulic line failure.
Another object is to provide an internal safety valve that directly mounts into the chute lift cylinder barrel.
Still another object of the present invention is to provide a quick responsive flow fuse that adds minimal bulk to the hydraulic cylinder.
These and other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings which like numerals in the several views refer to corresponding parts.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial side view of a ready mix concrete truck with an extended concrete chute incorporating the present invention;
FIG. 2 is a view of a retracted hydraulic cylinder partially cut away to show the location of the safety valve in the barrel of the hydraulic cylinder;
FIG. 3 is a view of an extended hydraulic cylinder partially cut away to show the location of the safety valve in the barrel of the hydraulic cylinder;
FIG. 4 is a cross sectional view of the hydraulic cylinder with the flow valve in an open position.
FIG. 5 is a cross sectional view of the hydraulic cylinder with the valve in a closed position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a work type vehicle, namely a ready mix concrete truck, is indicated generally by 10. It includes a rotatable mixer drum 12. Cement or concrete is emptied through discharge spout 13 into a discharge chute 15. This discharge chute 15 is used to cause the concrete to flow into a bucket, wheel barrel or to a space defined by erected concrete forms. Discharge chute 15 is positioned by means of the chute lift hydraulic cylinder 20. Workers also pull and tug on the chute for lateral positioning thereof.
The present invention relates to a hydraulic cylinder safety valve assembly designated generally as 21, consisting of a safety valve device 25 located within the discharge chute cylinder 20. A hydraulic hose 28 is connected to the inport valve 30 of the discharge chute cylinder 20. The discharge chute cylinder used typically is a displacement single action hydraulic cylinder. Controlled flow of the hydraulic fluid is from the hydraulic hose 28 into the cylinder 20 when the cylinder is extended and from the cylinder 20 to the hydraulic hose when the cylinder is retracted. The cylinder 20 consists of a barrel 32, piston 34, cylinder mount 36 and a moving seal 38. The cylinder mount is drilled and tapped for the intake valve 30 and the safety valve 25. A bore 40 connects intake valve 38 with a longitudinal bore 41 of the safety valve device 25. The safety valve 25 is located within bore 31 of the cylinder barrel 32 adjacent the cylinder mount 36. The piston 34 is mounted for reciprocation within the barrel 32. When the piston 34 is in the extended position the cement chute is raised as shown by the solid lines in FIG. 1. When the piston 34 is in the retracted position as shown in FIG. 3 and by the broken lines of FIG. 1, the cement chute 15 is lowered. The piston 34 has an internal cavity 35 which receives the safety valve 25 when in the retracted position shown in FIG. 3.
The safety valve 25 is shown in FIGS. 2, 3, 4 and 5. The safety valve 25 is threaded onto the cylinder mount 36. The valve 25 contains a longitudinal bore 41 and counter bore 42. The counter bore 42 contains a moveable cylindrical spool 44, compression spring 46, and a poppet 48 which will be described in further detail below. The poppet valve seat 48 is located in the counter bore 42 and has a radial flange 50 and base 52 containing opening 54. The flange 50 is located at the end of the valve 25 adjacent the cylinder mount 36 and longitudinal bore 41. The poppet 48 has a main cylindrical body 56 containing a bore 58. The main cylindrical body 56 tapers to a section containing two opposed ports. These two ports 60 and 62 provide for fluid communication between the poppet bore 58 and the valve interior 42. The poppet 48 then tapers into a conical end 64.
The spool 44 is located within counter bore 42. The spool spring 46 is also located within bore 42 and extends into the spool interior 66. A portion of spool spring 46 surrounds the poppet 48. FIG. 4 shows the spring during controlled flow. Spool spring 46 provides the biasing means to urge spool 44 away from the poppet 48, creating a fluid passage way through the ports 60 and 62 into the spool interior 66 and through the spool aperture into the cylinder barrel. The valve operates to restrict flow when the fluid pressure on the spool surrounding the aperture increases compressing spool spring 46 forcing the spool aperture 68 against the conical end 64 of the poppet 48. This is the closed position shown in FIG. 5. The aperture 68 of the spool 44 is of a diameter greatly smaller than the diameter of the spool and the counter bore 42. This aperture may, for example, be 0.125".
The arrows in the FIGS. 2 and 3 show the flow of fluid from the cylinder through the valve during extension and retraction of the cylinder. In FIGS. 2 and 4, hydraulic fluid flows from the cylinder port fluid inlet valve 30 into the cylinder mount bore 40 and then into the flow valve inlet 41. From the inlet 41, fluid passes into the poppet bore 58 and out of the ports 60 and 62. The flow then enters the interior 66 of the spool 48 where it passes through the spool aperture 68 into the counter bore 42 and finally through flow valve port 49 into the cylinder barrel. The introduction of fluid into the hydraulic cylinder barrel 32 and bore 35 causes the piston 34 to extend from the cylinder barrel 32. When it is desired to retract the piston 34 to lower the cement chute 15, the hydraulic fluid is released from the hydraulic piston 34 and flows in the opposite direction through the valve 25.
Fluid will readily pass in either direction when the flow rate in the valve 25 is less than a predetermined rate, e.g., approximately four gallons per minute. The flow rate less than the predetermined rate is the controlled rate of the hydraulic system. The spring 46 has sufficient stiffness such that the fluid pressure on the spool surface as fluid enters the spool aperture 68 is insufficient to cause the spool 44 to move against the force of the spring 46. When the flow rate into the valve 25 from the cylinder 20 exceeds approximately four gallons per minute, the fluid pressure on the spool 44 surface will increase as the fluid rushes to enter the spool aperture 68. The increased fluid pressure on the spool 44 surface causes the spool 44 to move against the force of the spring 46 towards the poppet 48. The spool 44 moves until the aperture 68 engages the conical end 64 of the poppet 48. The spool aperture 68 is blocked thereby restricting fluid flow.
In the event the hydraulic hose breaks, the fluid pressure decreases rapidly on the system port end. Hydraulic fluid leaves the cylinder 20 at an increased flow rate to compensate for the sudden pressure decrease. Accordingly, fluid pressure increases against the spool 44 surface as the hydraulic fluid rushes to enter the spool aperture 68 at an increased flow rate. When the flow rate exceeds the predetermined flow rate, the spool 44 moves against the force of the spring 46 towards the poppet 48. The flow is restricted as the conical end 64 of the poppet engages the spool aperture 68. Hydraulic fluid can no longer flow through the safety valve. Consequently, the hydraulic fluid remains in the hydraulic cylinder maintaining the position of the concrete discharge chute.
It is understood that the above disclosure of the presently preferred embodiment is to be taken as illustrative of the invention. Furthermore, it is to be understood that those skilled in the art be capable of making modifications without departing from the true spirit and scope of the invention.
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An internal safety valve for preventing the discharge chute from rapidly falling due a sudden loss of hydraulic fluid pressure. A safety valve assembly for use in a hydraulic cylinder consisting of a safety valve located in the barrel of a hydraulic cylinder. The moveable piston of the hydraulic cylinder has a cavity for receiving the safety valve therein. The safety valve is actuated when the flow leaving the chute lift cylinder exceeds a predetermined flow. The valve immediately stops the hydraulic fluid from leaving the chute lift cylinder maintaining the position of the discharge chute.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a structure of a vertical cavity surface emitting laser that emits light vertically to a substrate, and more particularly to a low cost light source in optical communications systems and optical information systems such as LANs and Datacoms.
[0003] 2. Description of the Related Art
[0004] A vertical cavity surface emitting laser that oscillates at 1.3 μm and 1.55 μm is now required as a light source for optical transmission systems. To achieve the vertical cavity surface emitting laser having excellent device characteristics, a high quality active layer and mirrors need to be formed simultaneously.
[0005] Mainly a band gap of a gain medium in an active layer determines an oscillation wavelength of a semiconductor laser. InGaAs(P) and InAlGaAs lattice-matched to an InP substrate are generally used for obtaining a long wavelength laser beam. These materials are widely used in active layers of the vertical cavity surface emitting lasers because crystals with high quality crystallinity can be obtained using these materials.
[0006] Since the vertical cavity surface emitting laser emits a laser beam vertically to a semiconductor substrate, mirrors of the resonator need to be formed vertically to the laser beam, namely horizontally to the semiconductor substrate. The mirrors are formed by epitaxially growing several to several dozen pairs of two types of thin layers whose refractive indexes are different from each other. The thickness of each layer is λ/4 optical thickness. Such mirrors are called DBR (Distributed Bragg Reflector) mirrors.
[0007] On the other hand, since a volume of the active layer, the gain region, is smaller than that of an edge emitting semiconductor laser, the mirrors of the laser resonator need a high reflectivity of over 99%. For example, as the conventional mirror, there is a DBR mirror formed of Al(x)Ga(1-x)As and Al(y)Ga(1-y)As (0≦x<y≦1) lattice-matched to a GaAs substrate. This AlGaAs material system, of which a reflector having highly quality crystallinity and a high reflectivity can be easily formed, is widely used in vertical cavity surface emitting lasers of 0.8 μm bands. Therefore, techniques of forming an active layer that oscillates at a long wavelength band on the GaAs substrate has been investigated. GaInNAs, GaAsSb, quantum dots of InGaAs, and highly-strained InGaAs with a high ratio of In are the examples. However, in these materials, crystals with highly-qualified crystallinity cannot be produced. Thus, the materials are not in practical use.
[0008] DBR mirrors on the InP substrate, on which an active layer with high crystallinity can be formed, has been investigated. A vertical cavity surface emitting laser on the InP substrate reported in IEEE Photonics Technology Letters, Vol. 7, pp. 608-610, 1995 uses a combination of semiconductor films of InGaAsP and InP as the mirrors. The refractive index difference between these two semiconductors is so small that forty five pairs of the semiconductors, namely ninety layers, need to be epitaxially grown to obtain a reflectivity of over 99%. Such crystal growth requires a long growth time, decreasing the crystallinity and the uniformity and controllability of the film thickness. Additionally, the laser beam penetrated the mirror so deeply that scattering loss of the mirror might degrade the device characteristics. Further, in such a combination, it was difficult to adjust the wavelength band where high reflectivity could be obtained, namely the stop band, to a wavelength of the gain region because the stop band was narrow. This meant not only that the device yield ratio decreased, but also that the wavelength of the gain region did not match to the stopband when the device was driven without a temperature control and thereby the device could not operate.
[0009] On the other hand, in IEEE Journal On Selected Topics In Quantum Electronics, vol. 6, pp.1244-1253, 2000, it has been reported that calculations show that the characteristics of AlGaAsSb mirrors on the InP substrate can be equal to those of AlGaAs mirrors on the GaAs substrate. In addition, a vertical cavity surface emitting laser using the AlGaAsSb mirrors has been reported by the University of California, whose presentation number was ThCl, at Int'l Semiconductor Laser Conference 2000.
[0010] However, as described below, since it was extremely difficult to produce high quality crystals using the AlGaAsSb materials, the high quality and high reflectivity mirrors could not be produced. The crystallinity of the active layer that is grown on the mirror also degraded. Thus, the device characteristics and reliability deteriorated.
[0011] The difficulty of growing high quality crystals using AlGaAsSb materials is described below. In a quaternary alloy of GaAlAsSb and ternary alloys of GaAsSb and AlAsSb, the elements do not mix evenly and thereby crystals of different compositions are formed when the composition ratio is at a given ratio. This is called a compositional segregation. The region of ratios at which the compositional segregation occurs is called an immiscibility region. The calculation result of the immiscibility region of the AlGaAsSb quaternary alloy has been reported in Japan Journal of Applied Physics, vol. 21, p. 797, 1982.
[0012] [0012]FIG. 3 shows the calculation result. The horizontal axis indicates ratios of an alloy of Al and Ga, the compositions of group III elements. At the far left side, the alloy ratio of Al is 1.0, indicating that the group III elemental composition consists of only Al. At the far right side, the group III elemental composition consists of only Ga. Between the ends, the compositions of both elements are indicated. For example, at the point of 40% from the left end, the composition of Al and Ga is 60:40. The vertical axis indicates the group V element compositions. At the bottom, the alloy ratio of Sb is 1.0, indicating that the group V elemental composition consists of only Sb. At the top, the alloy ratio of As is 1.0, indicating that the group V elemental composition consists of only As.
[0013] The compositional elements inside the circles or partial circles of FIG. 3 segregate because of the immiscibility. To achieve an alloy having high crystallinity, compositions outside the circles are required. The numbers attached to the circles indicate temperatures. The circles indicate the immiscibility regions at the temperatures. Once formed, an alloy keeps its formed condition stably. Therefore, a high-quality alloy can be formed using compositions outside the immiscibility region at temperatures at which the alloy is formed.
[0014] To produce a device, an alloy needs to be lattice-matched to a semiconductor substrate. FIG. 3 shows compositions lattice-matched to a InP substrate. The compositions on the lines of the circles need to be used in producing the device on the substrate. The crystal growth temperature of the compositions needs to be at least equal to or over 800 degrees Celsius to prevent the compositional segregation. On the other hand, desorption of group V elements such as P and As occurs in the crystal when the crystal grows at over 800 degrees Celsius and, therefore, a high quality crystal cannot be obtained. When the crystal grows at temperatures between 500 and 700 degrees Celsius to prevent the desorption, the crystal is formed inside the immiscibility region. The elements do not mix evenly inside the immiscibility region so that the composition segregates. A strain and the like caused by the lattice constant difference between the alloy and the substrate result in the crystal deterioration. A high reflectivity mirror cannot be formed because of the crystal deterioration. Further, the crystallinity of an active layer growing on the deteriorated crystal also deteriorates. As described above, with the conventional AlGaAsSb alloy, the semiconductor mirror having high quality crystallinity could not be produced.
SUMMARY OF THE INVENTION
[0015] The present invention provides a vertical cavity surface emitting laser having on its InP substrate a high quality active layer and high quality mirrors with high reflectivity.
[0016] In a vertical cavity surface emitting laser having on its InP substrate an active layer that emits light and a resonator structure where mirrors located above and below the active layer to obtain a laser beam from the light, and emitting the laser beam perpendicularly to the plane of the substrate. At least one of the mirrors of the vertical cavity surface emitting laser of the present invention comprises an AlGaAs/AlGaSb superlattice having an average composition of Al(x)Ga(1-x)AsSb and an AlGaAs/AlGaSb superlattice having an average composition of Al(y)Ga(1-y)AsSb (0≦x<y≦1). Additionally, a waveguide is formed by etching around the active region until the bottom of the waveguide extends to the substrate. The waveguide groove is then filled with semiconductor material. Remarkable efficiency is shown when the cavity extends to the substrate. Further, the present invention comprises a semiconductor laser module using the above-described vertical cavity surface emitting laser.
[0017] Effects of the invention will be described in the following.
[0018] AlGaAsSb lattice-matched to the InP substrate at a usual crystal growth temperature is inside the immiscibility region where it is difficult to form the high quality alloy using AlGaAsSb. On the other hand, as shown in FIG. 3, AlGaAs and AlGaSb are outside the immiscibility region even at 400 degrees Celsius, far lower than the usual crystal growth temperature, so that the high quality crystal using AlGaAs and AlGaSb can be obtained.
[0019] On the other hand, it is known that a refractive index of the laser beam is equal to that of an average composition of a layer formed by epitaxialy growing alternative layers sufficiently thinner than a wavelength of the laser beam. For example, a layer having nearly the optical equivalence to an AlGaAsSb quaternary alloy can be obtained by epitaxialy growing thin layers of AlGaAs and AlGaSb alternatively. FIGS. 2A and 2B show a case when this fact is applied to an AlGaAsSb mirror. FIG. 2A shows a conventional structure of the mirror formed of an AlAsSb/GaAsSb alloy. A mirror having high crystallinity cannot be obtained using this structure because of the above described influence of the immiscibility. In a preferred structure of the invention shown in FIG. 2B, the AlAsSb layer consists of a combination of thin films of AlAs and AlSb, and the GaAsSb layer consists of a combination of thin films of GaAs and GaSb. In the process of forming superlattices, the film thickness ratio between AlAs and AlSb or GaAs and GaSb is adjusted so that the average lattice constant of these layers are lattice-matched to the InP substrate. As a result, for the laser beam, the superlattices are just like an AlGaAsSb alloy on the InP substrate. Due to the structure of the invention, an AlGaAsSb superlattice mirror having high quality crystallinity at a usual growth temperatures in the range of 500 to 600 degrees Celsius can be obtained. FIG. 2B shows the superlattice whose average composition is a ternary composition of AlGaAs and GaAsSb. The immiscibility region of FIG. 3 shows that a superlattice consisting of thin films of AlGaAs and AlGaSb, whose average composition is AlGaSb, also exhibits the above-described effect.
[0020] Further, by properly designing the film thickness of AlGaSb and AlGaAs, the average composition of the superlattice provides a larger band gap than that of the AlGaAsSb alloy due to a quantum effect. When the mirror consists of a layer having a band gap smaller than a wavelength of a laser beam, the layer absorbs the light, causing negative influence to the laser characteristics. The superlattice mirror has a larger band gap than the alloy, and thus absorbs less laser beam than the AlGaAsSb alloy would absorb. The structure using the superlattice consisting of AlGaAs and AlGaSb is meaningful because, generally, the smaller number of elements that form an alloy, the easier the crystal growth and a crystal film is produced with high-quality crystallinity. As described above, a preferred semiconductor mirror of the present invention is formed of superlattices, not alloys.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] For the present invention to be clearly understood and readily practiced, the present invention will be described in conjunction with the following figures, wherein like reference characters designate the same or similar elements, which figures are incorporated into and constitute a part of the specification, wherein:
[0022] [0022]FIG. 1 shows a vertical cavity surface emitting laser structure according to a preferred Embodiment of the present invention;
[0023] [0023]FIG. 2A shows a band gap structure of a conventional mirror;
[0024] [0024]FIG. 2B shows a band gap structure of a mirror of a preferred embodiment of the present invention;
[0025] [0025]FIG. 3 shows the immiscibility region;
[0026] [0026]FIG. 4 shows another preferred vertical cavity surface emitting laser of the present invention; and
[0027] [0027]FIG. 5 shows a preferred module using the vertical cavity surface emitting laser of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, other elements that may be well known. Those of ordinary skill in the art will recognize that other elements are desirable and/or required in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. The detailed description of the present invention and the preferred embodiment(s) thereof is set forth in detail below with reference to the attached drawings.
[0029] Preferred embodiments of the invention are described below with reference to the FIGS. 1, 3, 4 , and 5 .
Embodiment 1
[0030] A first preferred embodiment of the invention is described with reference to FIG. 1. This preferred embodiment shows a vertical cavity surface emitting laser that oscillates at a wavelength of 1.55 μm band for a light source for Datacoms and LANs. FIG. 1 is a cross-sectional perspective view.
[0031] Illustrated in FIG. 1, reference numerals 2 and 6 are semiconductor multilayer mirrors formed of superlattices. These mirrors are formed by epitaxialy growing low refractive index layers and high refractive index layers alternatively. The thickness of each layer is ¼ wavelength in the semiconductor. The low refractive index layer is formed of a superlattice made of thin films of AlAs and AlSb. The average lattice constant of the low refractive index layer is assigned to that of an InP substrate so that the layer is lattice-matched to the substrate. The high refractive index layer is formed of a superlattice made of thin films of GaAs and GaSb. The average lattice constant of the high refractive index layer is assigned to that of the InP substrate so that the layer is lattice-matched to the substrate.
[0032] [0032]FIG. 1 shows an n-type substrate 1 , an n-type superlattice semiconductor multilayer mirror 2 formed by epitaxialy growing alternatively superlattice layers having an average composition of GaAsSb and superlattice layers having an average composition of AlAsSb, an n-type InP spacer layer 3 , an active layer 4 formed of an undoped InGaAs strained quantum well layer and an undoped InGaAsP barrier layer, a p-type InP spacer layer 5 , a p-type superlattice semiconductor multilayer mirror 6 formed by epitaxialy growing alternatively superlattice layers having an average composition of GaAsSb and superlattice layers having an average composition of AlAsSb, a p-type InGaAs contact layer 7 , an insulating film 8 , polyimide 9 , a positive electrode 10 , negative electrode 11 , and output laser beam 12 .
[0033] A preferred method of fabricating the vertical cavity surface emitting laser of this preferred embodiment is described below. With a MBE (Molecular Beam Epitaxy) method, the superlattice semiconductor multilayer mirror 2 , the n-type InP spacer layer 3 , the active layer 4 , the p-type InP spacer layer 5 , the superlattice semiconductor multilayer mirror 6 , and the p-type InGaAs contact layer 7 are formed on the n-type substrate 1 . Next, with a photolithography and etching method, a circle shaped mesa structure is formed. With a thermal or plasma CVD (Chemical Vapor Deposition) method, the insulating film 8 is formed, and then, with a coating and an etchback method, the polyimide 9 is formed. Lastly, the positive electrode 10 and the negative electrode 11 are formed.
[0034] The invention embodies a high quality and high reflectivity mirror on an InP substrate, on which a high quality active layer can be achieved. The vertical cavity surface emitting laser of the present invention has lasing wavelengths of 1.3 and 1.55 μm bands and can be used for light emitting systems.
[0035] The vertical cavity surface emitting laser of this first preferred embodiment of the present invention operated continuously at room temperature. The threshold current was about 100 μA. The laser beam was emitted through the substrate. The lasing wavelength at room temperature was 1.55 μm and the laser had a long life of over one hundred thousand hours.
Embodiment 2
[0036] A second preferred embodiment of the present invention is described below with reference to FIGS. 4 and 5. This preferred embodiment shows a vertical cavity surface emitting laser with a wavelength of 1.3 μm band, intended for a light source for the optical transmission systems.
[0037] [0037]FIG. 4 is a cross-sectional perspective view. FIG. 5 shows a module incorporating the vertical cavity surface emitting laser of this second preferred embodiment.
[0038] In FIG. 4, reference numerals 14 and 18 refer to semiconductor multilayer mirrors formed of superlattices. These mirrors are formed by epitaxialy growing low refractive index layers and high refractive index layers alternatively. The thickness of each layer is ¼ wavelength in the semiconductor. The low refractive index layer is formed of thin films of AlAs and AlSb. The average lattice constant of the low refractive index layer is assigned to that of the InP substrate so that the layer is lattice-matched to the substrate. The high refractive index layer is formed of thin films of AlGaAs and AlGaSb. The average lattice constant of the high refractive index layer is adjusted to that of the InP substrate so that the layer is lattice-matched to the substrate. The composition ratio between Al and Ga, group III elements, is 5:95.
[0039] The cavity forming the mesa is buried with InP so that heat of the active layer is easily dissipated. Since a binary alloy has generally a higher heat conductivity than a ternary alloy, the structure where the InP buried layer reaches the InP substrate is efficient for heat dissipation.
[0040] [0040]FIG. 4 shows an n-type InP substrate 13 , a superlattice semiconductor multilayer mirror 14 formed by epitaxialy growing superlattice layers having an average composition of AlGaAsSb and superlattice layers having an average composition of AlAsSb alternatively, an n-type InP spacer layer 15 , an active layer 16 formed of an undoped InGaAs strained quantum well layer and an undoped InAlGaAs barrier layer, a p-type InP spacer layer 17 , a superlattice semiconductor multilayer mirror 18 formed by epitaxialy growing superlattice layers having an average composition of AlGaAsSb and superlattice layers having an average composition of AlAsSb alternatively, a p-type InGaAs contact layer 19 , an insulating film 20 , an insulating InP buried layer 21 , a positive electrode 22 , a negative electrode 23 , and an output laser beam 24 .
[0041] A preferred method of fabricating the vertical cavity surface emitting laser of this second preferred embodiment is described below. With an MBE method, a superlattice semiconductor multilayer mirror 14 , an n-type InP spacer layer 15 , an active layer 16 , a p-type InP spacer layer 17 , a superlattice semiconductor multilayer mirror 18 , and a p-type InGaAs contact layer 19 are formed on the n-type InP substrate 13 . Next, with a thermal or plasma CVD method, a SiO2 or SiNx film is formed as a mask for a mesa and a selective crystal growth, and a circle shaped pattern is formed on the film with a photolithography and etching method. The circle shaped mesa is formed using the insulating film as the mesa mask, as shown in FIG. 4. With an MOVPE (Metalorganic Vapor Phase Epitaxy) method, the insulating InP buried layer 21 is formed using the insulating film as the selective growth mask. Then that insulating mask is removed by etching. With the CVD method, the insulating film 20 is formed. Lastly, the positive electrode 22 and the negative electrode 23 are formed.
[0042] The vertical cavity surface emitting laser of this second preferred embodiment operated continuously at room temperature. The threshold current was about 100 μA. The laser beam was emitted through the substrate. The lasing wavelength was 1.3 μm and the laser had a Long life of over one hundred thousand hours.
[0043] Next, a preferred CWDM (Coarse Wavelength Division Multiplexing) light source module for LANs of the present invention is described as one example of a use of the vertical cavity surface emitting laser in a module. FIG. 5 shows a preferred structure of such a module. A laser driver 26 translates input electrical signals 25 to laser driving signals that drive the vertical cavity surface emitting lasers 27 of the present invention. A multiplexer 28 multiplexes light signals emitted from the lasers 27 . The multiplexed signals output through an output optical fiber 29 which is a single mode fiber. The lasers operate without a temperature control such as e.g., a Peltier element. Wavelengths of the lasers λ 1 to λ 4 are 1276, 1300, 1325, and 1350 nm, respectively. The lasers operated at 3.125 GBd for a light transmission of 2 km. There was no crosstalk between signals of the wavelengths, realizing a code error ratio of under 10E-12.
[0044] The foregoing invention has been described in terms of preferred embodiments. However, those skilled, in the art will recognize that many variations of such embodiments exist. Such variations are intended to be within the scope of the present invention and the appended claims.
[0045] Nothing in the above description is meant to limit the present invention to any specific materials, geometry, or orientation of elements. Many part/orientation substitutions are contemplated within the scope of the present invention and will be apparent to those skilled in the art. The embodiments described herein were presented by way of example only and should not be used to limit the scope of the invention.
[0046] Although the invention has been described in terms of particular embodiments in an application, one of ordinary skill in the art, in light of the teachings herein, can generate additional embodiments and modifications without departing from the spirit of, or exceeding the scope of, the claimed invention. Accordingly, it is understood that the drawings and the descriptions herein are proffered by way of example only to facilitate comprehension of the invention and should not be construed to limit the scope thereof.
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A vertical cavity surface emitting laser, useful as a light source in a semiconductor laser module, comprising an InP substrate having an active layer that emits light and a resonator structure having mirrors located above and below the active layer to obtain a laser beam from the light and emit the laser beam substantially perpendicular to the substrate, where at least one of the mirrors is made of AlGaAs/AlGaSb superlattices having an average composition of Al(x)Ga(1-x)AsSb and AlGaAs/AlGaSb superlattices having an average composition of Al(y)Ga(1-y)AsSb (0≦x<y≦1).
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FIELD OF THE INVENTION
This invention relates to a water purification system which incorporates a double pass reverse osmosis membrane assembly for filtering pretreated water and to a method of operating such a system.
BACKGROUND OF THE INVENTION
A typical prior art water purification system is illustrated in FIG. 1 . Feed water is pretreated at 20 and fed to a first storage tank 22 prior to heating in a heat exchanger 24 to a specified membrane operating temperature, typically 25° C. Pre-treatment equipment, which is based on the potable source water quality, typically comprises a multimedia filter to remove particulates, a softener to remove mineral scale, a carbon filter to remove chlorine/chloramines or a chemical injection system using a bisulphite type chemical, possibly a UV station for bacteria kill, and prefilters (1-10 μm) to remove particulates prior to the water entering the reverse osmosis system. After some chemical additions 26 , the water is fed to a reverse osmosis membrane assembly 28 and the purified water is treated with ultraviolet light in a first UV station 30 , deionized at deionization station 32 , treated in a second UV station 34 , and passed through a first sterilizing filter 36 before being fed to a second storage tank 38 . Water is drawn from the second storage tank 38 at various points of use generally indicated by reference numeral 40 after appropriate treatment including a third UV station 42 , a second sterilizing filter 44 and a second heat exchanger 46 to maintain ambient temperatures. Water from the second storage tank 38 is also recirculated through an ozonation system 48 with a pump 50 to reduce bacterial growth. An alternative microbial control design may include a heat exchanger for periodic heat sanitization.
It will be seen from FIG. 1 that excess reject water from the reverse osmosis membrane assembly 28 is drawn through pump 52 to be recirculated to the reverse osmosis membrane assembly 28 while the balance of the reject water is sent to drain. Operation of the system is controlled with a central programmed logic controller (PLC) indicated at 54 .
The system is quite complicated in that it has many technologies to monitor and control. The majority of these types of systems are custom built due to the variability of source water and the intricacies of different production demands. With the current approach in the industry, a human operator cannot control and monitor all of the variables to a satisfactory level. This necessitates an expensive PLC control system. The PLC system is also custom designed due to the above considerations. The complexity of this system dictates long lead times for delivery of the equipment. Once the equipment is placed at location, a long process is employed to adjust all of the technologies in order to maintain the desired water quality. Regular cleaning and sanitization must be performed on the equipment to ensure microbial integrity. Due to the variety and complexity of equipment employed, the maintenance is high. If one piece of equipment fails, the water production process ceases. Depending on the location of the failure, it may dictate sanitization of the equipment or system prior to placing it back into service. This represents lost production time. The complexity of the equipment dictates a thorough investigation and testing prior to releasing the system for production. High-energy input is required to temper the water (increase to 20-25° C.) to feed the system and meet reverse osmosis membrane specifications. In addition, high energy consumption and labour are required to maintain the system within specifications. The percent of water recovery or yield is low, being typically 60 to 75 percent of the system's demand.
Microorganisms, specifically bacteria, form biofilm, which is an extra-cellular organic polymer (polysaccharide in nature). Biofilm can also incorporate divalent metal ions that can form a lattice structure consisting of both organic and inorganic mass. This structure protects the organisms from sanitization and cleaning chemicals. Once this formation develops within a system it is very difficult to remove.
The storage tank is a grower of microorganisms unless an ozonation system is applied. This option is capital intensive and has associated operating and maintenance expenses. In addition ozone is a hazardous substance requiring appropriate safety precautions. Ozone is an added substance to the purified water in order to control the microbial integrity. In systems not employing ozone, the microbes will settle onto the tank surface, due to little movement of water (no velocity), and produce biofilm. Free-floating (planktonic) organisms will reproduce and contaminate the distribution system. Biofilm will protect the organisms from chemical sanitization and allow them to reproduce. Chemical sanitization will be reduced in effectiveness. Systems employing heat sanitization are capital and energy intensive and do not remove biofilm.
The typical prior art water purification system is not designed to prevent the growth of microbes. The approach has been to allow the microbial population to increase to a certain range in numbers, then to clean and/or sanitize the system, thus reducing the microbial population. Microbiological procedures require an incubation period of approximately two days or longer prior to enumeration. The delay in results can have the system out of specification for microbial numbers prior to cleaning and sanitizing. Alternatively, a high frequency scheduled cleaning and/or sanitization regimen is implemented to reduce the possibility of the microbial numbers exceeding specification. This approach is labour and energy intensive and prevents the use of the system while the procedures are being conducted. The design of the prior art does not inherently reduce or prevent the growth of microorganisms during the water purification process.
Various attempts to regulate the conductivity of high purity product water have been described in the prior art. A major problem identified in a double pass reverse osmosis system is the difficulty in rejecting gases such a carbon dioxide. Carbon dioxide present in the feed water will pass through the first pass membranes and the second pass membranes forming carbonic acid and the corresponding equilibrium equation products which result in increased conductivity of the product water. This phenomenon is viewed negatively by the prior art since the increase in conductivity is perceived as decreasing the quality.
The following equations express the carbonic acid formation and equilibrium:
Carbonic acid formation
Carbonic acid equilibrium
It is noted that the formulas were not reproduced in the form in which they were filed. The arrows are missing. If necessary, they may be replaced by equal signs.
Methods attempted for removing carbon dioxide are described in several US patents some of which are discussed below. In U.S. Pat. No. 4,574,049 and U.S. Pat. No. 5,997,745 an alkaline agent is added between the first and second pass to convert the carbon dioxide gas to carbonate which is rejected by the second pass membranes. Addition of an alkaline is used prior to the first pass in conjunction with an acid to the second pass with or without a gas liquid separation module in U.S. Pat. No. 5,766,479. Gas removal by hydrophobic gas permeable membrane contactors is described in patents U.S. Pat. No. 5,156,739 and U.S. Pat. No. 5,670,053. Removal by a forced draft decarbonator and a vacuum degasifier is explained in U.S. Pat. No. 5,338,456 and U.S. Pat. No. 5,250,183. Removal by a forced/induced draft decarbonator before or after a two pass reverse osmosis system is disclosed in U.S. Pat. No. 5,925,255. One solution described in U.S. Pat. No. 6,258,278 is to first treat feed water with a strong base anion resin and subsequently removing carbon dioxide in order to maintain a high pH of 6 to 9.5. U.S. Pat. No. 6,080,316 and U.S. Pat. No. 6,126,834 describe the use of caustic injections to adjust the pH of the infeed water that is controlled by a PLC based on resistivity measurements of the product water. These patents plus others describe a removal process for CO 2 or methods of preventing the CO 2 from ending up in the product water. These patents view the increase in conductivity due to the presence of CO 2 in the product water negatively.
Prior art water purification systems are typically designed to produce the purified water at a defined rate. It is usually based on the maximum required water volume demand during a period of time (hour, shift, day or number of dialysis machines, etc.). To this rate a storage tank can be sized to provide this maximum rate with a minimum buffer volume of approximately 20 percent. The systems cannot vary their production rate by more than a few percentages of the original designed rate.
The object of the invention is to provide a better means of producing water that will meet the specifications of Purified Water and Water for Injection as defined by the United States Pharmacopeia Convention Inc. (as defined but not limited to the current edition XXV) and water for dialysis as defined by the American Association for Advancement of Medical Instrumentation (AAMI).
The invention provides a means of purifying water that supplies the purified water to the point or points of use to allow the water to be drawn immediately on demand. The water that is not used immediately is recycled and repurified to ensure continuous quality.
Another object of the invention is to provide purified water directly to the point or points of use without the requirement for a storage and distribution system. The means of providing the water directly to the point of use is an integral part of the purification process.
The invention's objective is to provide purified water having very low microbial counts. Still another object of the invention is to provide a means of purifying water, which is not conducive to growth of microorganisms within the purification process.
In addition, the object of the invention is to provide a means of removing microorganisms that may grow within the purification process.
The object of the invention is also to provide variable production rates to meet variable demand requirements. In addition this saves energy and water.
It is another object of the invention to provide a means to self-clean the purification system of mineral scale and microorganisms.
Still another object of the invention is to allow the system to self-purge itself of purified water that does not meet the conductivity or temperature parameters.
The objects of this invention include providing a water purification system, which can be operated to produce high purity water at a reduced capital cost investment and with lower operating costs.
SUMMARY OF THE INVENTION
Sanitation and cleaning of the system is done by controlling the pH so that it is normally acidic in contrast to prior art systems and this is done naturally without any acid additions by maintaining a high carbon dioxide concentration in solution, the carbon dioxide being concentrated into the permeate from a reverse osmosis membrane assembly used to purify the water. To increase pH to neutral values for end uses, or reduce the conductivity of the purified water by that contributed by the CO 2 , a base may be added or carbon dioxide may be allowed to escape from solution.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to better understand the invention, illustrative embodiments of a water purification system are described below with reference to the accompanying drawings, in which:
FIG. 1 is a schematic flow diagram showing a typical prior art water purification system including a single pass reverse osmosis membrane assembly and a distribution system including a storage tank;
FIG. 2 is a schematic flow diagram showing a water purification system according to the invention and including a double pass reverse osmosis membrane assembly with points of use and operating at a cold temperature;
FIG. 3 is a schematic flow diagram showing a water purification system according to the invention and including a double pass reverse osmosis membrane assembly with points of use and operating at a hot temperature, or to be operated cold and to be periodically hot water sanitized;
FIG. 4 is a schematic flow diagram showing a water purification system according to the invention and including a double pass reverse osmosis membrane assembly with points of use and operating at a cold temperature and having a serpentine loop return after the purification system for continuous circulation in the loop;
FIG. 5 is a schematic flow diagram showing a water purification system according to the invention and including a double pass reverse osmosis membrane assembly with points of use and operating at a hot temperature and having a serpentine loop return for recirculated excess permeate not used at points of use;
FIG. 6 is a schematic flow diagram showing a water purification system according to the invention and including a double pass reverse osmosis membrane assembly with points of use and operating at both hot and cold temperatures;
FIG. 7 is a schematic flow diagram showing a water purification system according to the invention which is similar to the system drawn in FIG. 2 but which includes small degasification modules for sampling a fraction of product water;
FIG. 8 is a schematic flow diagram showing a water purification system according to the invention which is similar to the system drawn in FIG. 2 but which includes a large degasification module for removing CO 2 from all of the product water;
FIG. 9 is a schematic flow diagram showing a water purification system according to the invention which is similar to the system drawn in FIG. 2 but which includes a large degasification module for removing CO 2 from all of the product water in association with an eductor for returning CO 2 into the system upstream from a first reverse osmosis membrane assembly;
FIG. 10 is a graph showing the reduction in pH over time of the water circulating onto first pass reverse osmosis membranes when the system is operated in idle or circulation mode;
FIG. 11 is a graph showing the reduction in conductivity over time of the water circulating onto first pass reverse osmosis membranes when the system is operated in idle or circulation mode; and
FIG. 12 is a graph showing the reduction in alkalinity over time of the water circulating onto first pass reverse osmosis membranes when the system is operated in idle or circulation mode.
DESCRIPTION OF THE INVENTION
In its simplest embodiment, a water purification system in accordance with the invention and indicated generally by reference numeral 60 in FIG. 2 , has purified water (permeate) drawn directly from the purification process at points of use generally indicated by reference numeral 62 without any previous storage in a tank or locations where water will stagnate and be susceptible to bacterial growth.
The feed water is fed to appropriate pretreatment at 64 and optionally has its pH adjusted to a basic condition through the addition of sodium hydroxide (NaOH) at 66 whereafter it is passed through a first ultraviolet radiation treatment station 68 prior to being pumped with a variable speed pump 70 to a first reverse osmosis membrane assembly 72 .
The permeate from the first reverse osmosis membrane assembly 72 is fed to a second reverse osmosis membrane assembly 74 and its permeate is passed through a second ultraviolet radiation treatment station 76 before being drawn at various points of use 62 , as required. Excess permeate water not used at the points of use 62 , and a major portion of the reject water from both the first reverse osmosis membrane assembly 72 , and all of the reject water from the second reverse osmosis membrane assembly 74 is recycled through the first reverse osmosis membrane assembly 72 after passing through the first ultraviolet radiation treatment station 68 . The ultraviolet radiation treatment sterilizer station 68 is used to reduce the incoming microbial load from the pretreated source water and circulation water prior to entry into the first pass reverse osmosis membrane assembly 72 while the second ultraviolet radiation treatment sterilizer station 76 is used to kill organisms that will eventually grow on the downstream side of the membrane of the second reverse osmosis membrane assembly 74 .
The invention is characterized by the absence of a storage tank, which would otherwise provide fertile ground for microbial growth and contamination of permeate. This is rendered possible by appropriate design selection of the supply capacity to maintain an approximate minimum velocity of 3 ft/sec. (1 meter/sec.) and usually 5 to 7 ft/sec (2 meters/sec.) and by operating the system to keep the permeate in circulation. A minimum velocity to maintain a continuous turbulent flow condition within the piping is known to be approximately 3 ft/sec (1 meter/sec). Conveniently, maintaining a minimum turbulent velocity will reduce the growth of microorganisms and prevent the formation of biofilm on the walls of the point of use piping.
System production rate is designed based on the expected draw off demand and the appropriate serpentine pipe size with the corresponding velocity. Assuming an average pipe velocity of 6 ft/sec., systems can be built with common pipe sizes as follows:
1/8″ pipe (3.0 mm)
0.2 US gpm (0.85 Lpm)
{fraction (3/16)}″ pipe (4.8 mm)
0.5 US gpm (2.1 Lpm)
¼″ pipe (6.2 mm)
0.9 US gpm (3.8 Lpm)
⅜″ pipe (9.6 mm)
2.0 US gpm (8.5 Lpm)
½″ pipe (12.5 mm)
3.6 US gpm (15.0 Lpm)
¾″ pipe (19.0 mm)
8.0 US gpm (34.0 Lpm)
1.0″ pipe (25.4 mm)
14.5 US gpm 60.0 Lpm)
1.25″ pipe (32.0 mm)
23.0 US gpm (95.0 Lpm)
1.5″ pipe (36.0 mm)
32.0 US gpm (135.0 Lpm)
2.0″ pipe (51.0 mm)
60.0 US gpm (240 Lpm)
2.5″ pipe (64.0 mm)
90.0 US gpm (380 Lpm)
3.0″ pipe (76.0 mm)
130 US gpm (550 Lpm)
3.5″ pipe (90.0 mm)
180 US gpm (750 Lpm)
4.0″ pipe (100 mm)
230 US gpm (950 Lpm)
Etc.
The required maximum demand at the points of use 62 would first be found. As an example, 30 US gpm. (120 Lpm) are required at the point of use on a continuous basis. In order to maintain an approximate minimum velocity of around 3 ft./sec. (1 meter/sec.) on the loop return, a system would have to produce 2 times the continuous amount required at the point of use. This would dictate a 2″ (51 mm) distribution loop and an average production rate of around 60 US gpm. (240 Lpm).
The invention is typically designed with a surface area of the first pass having 1.5 to a maximum of 3 times the surface area of the second pass membranes, but most usually 2 times. Ideally the first pass membrane flux (flow rate per unit surface area per unit time) is in a range of 10 to 20 gallons per square foot per day (406 to 812 litres per square meter per day). The water feed flow to the first pass membranes is typically a minimum of 3 times the average production rate from the second pass reverse osmosis assembly 74 to provide high cross flow that will reduce fouling of the membranes.
EXAMPLE
A phenomenon was discovered that produced two effects. The system is generally run in two different modes of operation. The “production mode” is defined when water is being drawn from the system. The “circulation or idle mode” of operation occurs when no water is being drawn off at the points of use. All water, except for reject water, is recirculated and repurified. A system of the same design as shown in FIG. 2 was operated for 30 minutes in production mode (water drawn from the system) under different product recovery levels (80%, 90% 95%) and then placed on idle or circulation mode having the same recovery levels. Osmonics Inc. manufactured the polyamide membranes, model designation AK8040, used in the system.
The tap water feed was first softened and then dechlorinated, using a bisulfite injection system, prior to a 5.0-micron cartridge filter system. The feed water had a pH of 7.2, a conductivity of 340 μS/cm. and alkalinity of 119 ppm. (as CaCO 3 ).
After a 30 minute production stabilization period, the circulating water fed to the first pass membranes was sampled for pH, conductivity and alkalinity, as a function of time for each product recovery level. FIGS. 10 , 11 and 12 show the effect of circulation mode over time for the reduction in pH, conductivity and alkalinity respectively.
The conductivity of the circulation water, which consisted of the new water entering the system, the majority of the water recycled from the reject of the first pass, all of the reject water from the second pass, and all of the product water, dropped to less than one half of the conductivity of the incoming feed water. In addition a second effect was observed that produced a corresponding reduction in pH (see FIG. 10 ) with the reduction in conductivity. The pH dropped to below 6.5 when the recirculating water's conductivity dropped below one half of the feed water conductivity. The rate of the effect to demonstrate itself was in proportion to the total dissolved solids in the recirculated water. The significant reduction in all three parameters from the production mode values to well below the tap feed water values demonstrates the self-cleaning ability of the invention when operated in circulation mode.
The second pass reverse osmosis product water in all three operating conditions, that is, at product recovery levels of 95%, 90% and 80% consistently had a pH of below 5.5.
The invention is further characterized by, the reverse osmosis membranes having the well known property of producing a permeate with dissolved carbon dioxide content. The water purification system 60 is operated to produce an acidic permeate during normal production and times when no water is drawn from the points of use at 62 (idle mode), the acidity in the permeate, and in the system, being increased in part by allowing the pH to decrease as a result of pressurizing the water to maintain carbon dioxide in solution.
An acidic condition is desirable to remove the inorganic fouling fraction from membrane surfaces and to reduce scaling. Minerals such as calcium and magnesium carbonates which are dissolved and maintained in solution are sent to drain. In addition, the high level of acid within the system will permeate the membranes and be distributed through the system sanitizing the whole reverse osmosis system and point of use piping. Microorganisms have an optimum pH range in which they grow. This range is ideally between pH 6.5 to 7.5. As the pH drifts above or below these values, the alkalinity or acidity becomes toxic to the organisms. Organisms that are commonly found in source water (i.e. Pseudomonades) will not grow in acid conditions. In fact, acid conditions at and below pH 5.5 will kill acid sensitive organisms. The area of most concern in the reverse osmosis system is the product spacer screens of the second pass. Reverse osmosis membrane manufacturers do not make claims for sterility of the permeate water. They do state that there will be >99% rejection of microorganisms. The first pass in theory will remove >2 logs and the second pass will reject approximately 2 logs. The problem that has been observed is that the organisms eventually culture and those, which pass the first stage, infect the second stage. The organisms that grow on the second stage will eventually pass into the permeate of the second stage. Due to the inherent design construction of reverse osmosis membranes, the organisms start to culture in the second pass permeate side of the membranes. This is the major area of infection that directly contributes to the contamination of the product water. The organisms then slough off into the water and infect the downstream piping. In this invention, the high acidic conditions after the second pass, approximately pH 5.5 or below, effectively prevent the growth of or kill the organisms that have cultured in the second pass permeate spacers.
The invention thus allows for self-sanitization without peripheral stations for additional, sterilizing filters, and ozonation systems typical of the prior art. The invention can maintain an undesirable state to prevent microorganisms from growing and to clean mineral deposits when the system is not called upon to produce water for a process. The ability of this invention to produce low pH product water, particularly on the permeate side of the second pass, will kill acid sensitive organisms and prevent growth of microorganisms. The invention operated under these conditions is the most desirable.
The ability to reduce the conductivity and pH of the water in circulation mode will allow for operation of the invention without the use of a water softener in the pretreatment. A softener would not be required in pretreatment for removal of water hardness under conditions where the feed water is low to moderately hard and the system is not called upon to produce water for a process on a continuous bases. The circulation or idle mode will clean the membrane of material collected during the production mode.
The current state of the membrane art has developed two different types of membranes: cellulose acetate (CA) and thin film composite (TFC) which are commonly employed in water purification. Each membrane has its strengths and weaknesses. The CA membrane is not susceptible to chlorine but is susceptible to basic conditions (high pH). The TFC membranes are not susceptible to high pH but are susceptible to chlorine. TFC membranes require chlorine removal—usually carbon or bisulphate injection. Carbon grows bacteria that will contaminate the system. If carbon is used, a provision is made to sanitize it with heat (hot water or steam increasing the cost of equipment and operating costs). Both membranes will tolerate low pH. A system using CA membranes would not require any form of pre-treatment (no chlorine removal, no softening/acid/anti-scale injection) other than a mechanical cartridge type filter for particulate removal. A system using TFC type membranes would not require softening/acid injection/anti-scale but would require a provision for particulate and halogen removal. The TFC system could incorporate a chlorine destruct ultraviolet system to destroy chlorine (i.e. as produced by Aquafine or Trojan). The ultraviolet system would be placed just prior to the pump. The acidified water would assist in preventing mineral scale build-up on the quartz sleeves forming part of the ultraviolet system and which would affect the overall intensity of the ultraviolet radiation into the water. The ultraviolet radiation would also inactivate microorganisms that would be introduced in the feed water and potentially any that would be derived from the distribution system.
Heat exchangers to temper the feed water are not required for operation of this device. It is well known in the art of membrane water purification that as the temperature decreases the water viscosity increases and visa versa. The water viscosity directly affects the production rate of the reverse osmosis membranes. This can be as-high as a decrease in production capacity of >2% for every degree C. below 25° C. (25° C. is the membrane manufacturers standard flux rating temperature). At 5° C. the decrease in production rate can exceed 40% at the same specified pressure. In decreasing water temperatures, to maintain the same production rate, a corresponding increase in pressure is required. Water purification systems incorporating the invention do not use heat exchangers to temper water for the following reasons:
a. The membrane surface area in the design is increased to account for the production loss due to temperature.
b. It is desirable from a microbiological point of view to maintain a low temperature within the reverse osmosis and point of use and return piping to decrease the rate of growth of microorganisms.
c. A significant amount of energy can be saved by not tempering the water to 25° C.
The selection of reverse osmosis membranes and the process design of this invention preclude the need to temper the feed water. Membrane manufacturers modelling programs (i.e. Osmonics and Dow) will determine the best membrane selection for the ionic quality of the product water as it relates to the temperature of the feed water. A combination of membrane surface area and types can be employed to obtain the desired ionic quality and production rate. Heating energy represents a significant contribution to operating costs on prior art systems and can be as high as 50% during the winter months in northern climates.
Cooling exchangers are not normally employed in the design of this device. The water rejected from the first pass membranes and the water drawn at points of use acts as a heat sink for the system. Typically an increase of approximately a couple of degrees Celsius is observed between the infeed temperature and the product water returning from the use points. The heat build up within the system is based on the percent recovery, the draw off volume with cycle rate, and the membranes' maximum allowable operating temperature. Storage based systems build up heat from the pump and frictional losses within the distribution system. These systems employ cooling exchangers to maintain the temperature usually between 20-25° C., which is an ideal temperature for microbial growth. Under conditions of high recovery rates where source waters are inherently warm (tropical climates) a cooling exchanger could be employed with this invention. The location of the exchanger would be on the infeed, or in the circulation system within the device (prior to the pump and membranes), thus insuring lower capital cost since sanitary design is not necessary as with storage based systems.
It will be appreciated that high temperature product water or water that does not meet the conductivity specification will be automatically sent to drain. A normal reject rate is established in the system usually between 2 and 50% of the product production rate or 50-98% recovery. The water rejected to drain and product water drawn off act as heat sinks to dump the heat from the system that is built up due to pump horsepower and friction. A conductivity/temperature sensor 14 , 18 measures product water quality on either the purified water supply line to the points of use 62 (product line) or on the return piping back to the reverse osmosis membrane assembly 72 . If water exceeds either or both limits, an automatic valve forming part of a reject assembly 73 on the reject line opens to dump additional water to drain. This acts to purge the system of water which in not within specification. After the quality has been re-established, the automatic valve 73 closes to return the system to normal operating conditions.
A variable frequency drive (VFD) is associated with the motor controlling pump 70 and used for hydraulic control within the system. A flow meter with sensor 12 , 16 on the product water line and/or point of use return line will monitor product flow rate. The sensor or sensors ( 12 , 16 ) will transmit a signal to the variable frequency drive to increase or decrease the speed of the pump motor 70 . The VFD will allow for operation of a water purification system according to the invention from a minimum of 3 feet per second (1 meter per second) to a maximum recommended velocity of 9 feet per second (2.7 meters per second). It will be understood that the system is designed for continuous operation so that water is never left stagnant. Exceeding 10 feet per second (3.0 meters per second) can produce water hammer within the system. This equates to a production rate as low as 50% of the average designed rate to a maximum of 150% of the average designed rate. The VFD is employed for different operating conditions and reasons:
a) During draw down the loop return flow sensor 16 will detect a decrease in flow. This will speed up the revolutions per minute (RPM) of the pump 70 to increase the applied pressure on the reverse osmosis membrane assemblies 72 , 74 , which in turn will produce more water to compensate for the draw down volume. This also maintains the minimum requirement of 3 feet per second (1 meter per second) velocity in the return line.
b) In northern climates, water sources can vary in temperature depending upon the season particularly if the source water is from a surface source (lake, river or reservoir). The VFD will automatically control the production rate based on product flow, irrespective of temperature and water viscosity. Temperature variation will not affect production rate.
c) Temporary adjustments can be made for increased or decreased water demand. Production rates can be modulated within defined parameters. A manual setting of the VFD can set the production rate from as low as 50% of the pumps RPM range to 100% of its range, which would produce a production, range of from 50% to 150% of the designed average production rate.
d) Maintaining the velocity in the point of use piping of ideally 3 feet per second (1 meter per second) but not to exceed 6 feet per second (2 meters per second) during idling times, when no water is drawn from the system, will reduce water consumption and power requirements to save energy. It also reduces the possibility of microbes from settling onto the piping wall that will eventually form biofilm and contaminate the system.
e) In the case of a power failure, the VSD will soft start the system. When power is restored, the pump 70 will initiate a slow ramp up to bring the system up to operating specifications increasing the RPM to operational speed. This prevents hydraulic shocks, which reduces ware and tear on the system and associated point of use equipment. The system will be self-regulating to return itself to producing the desired water quality and quantity.
f) Used during clean in place (CIP) of the system. The frequency drive would be set at around 50 percent of the motor's maximum frequency, in addition the back pressure regulating valves would be opened on the recirculation lines. This produces a good velocity of flow within the system at low pressures. During CIP, it is desirable to maintain a high velocity across the membranes at low pressures to lift the deposited material off the membrane surface. The cleaning chemicals can be dosed into the system with appropriate chemical neutralization on the first pass reject.
Energy efficiency can be realized with the use of submersible pumps. The water being pumped cools the motor. This heat energy is picked up by the water from the pump motor and friction through the distribution system and assists in reducing water viscosity, which increases production rate at a specified pressure. This in turn saves energy costs on pump horsepower.
Sanitary design considerations are used throughout. At least one pump 70 is used to apply pressure to the first pass. The residual pressure from the first pass is used to feed the second pass. This is a more sanitary design than a pump for the first pass and a second pump for the second pass. In addition, the pump 70 is located on the contaminated side of the purification process, which is upstream of the first set of membranes. If a pump 70 has to be replaced, sanitization of the process and point of use 62 piping would not be required as in the typical prior art. In addition a spare pump could be added to the system, swing elbows from the existing pump could be rotated over to the second pump very quickly to reduce down time.
The invention can be operated to regulate itself to maintain product water quality and quantity with only 2 sensors, a combination conductivity/temperature sensor ( 14 , 18 ) and a flow sensor ( 12 , 16 ). No other controls are required to allow the system to self regulate. The flow sensor ( 12 , 16 ) will provide the feedback for the VFD to maintain the velocity and production rate. The conductivity/temperature sensor ( 14 , 18 ) will regulate the automatic valve located on the reject assembly 73 to send high temperature or conductivity water to drain which will clear the system quickly and maintain the hydraulic balance.
The system can be operated with very simple controls. A programmed logic controller (PLC) or proprietary control systems are not required for operation.
The invention is adaptable to various source water qualities up to approximately 2,000 mg/L of total dissolved solids (TDS) based on the existing membrane art. Adjustments can be made to the percent recovery on the system to ensure the final product water quality (from 50% to 98%). In addition, choices can be made of different membranes having different rejection characteristic to assist in the final water quality. As membrane technology advances, higher rejection membranes can be employed to use this device on even higher TDS source water. In cases where the source water exceeds recommended operating guidelines, as specified by the membrane manufacturers, appropriate pre-treatment, as designed by those skilled in the art of water purification, can be employed.
Typical two pass reverse osmosis systems in the prior art are usually designed to run with a 50-60% overall recovery. The typical recovery for this design is 80 to 98% during the production mode. The percent recovery would be dependant on source water temperature and total dissolved solids level.
Where system recovery, in the production mode, is below 90%, it can be increased to 90-98% when operated in circulation or idle mode by using an additional automated valve on the reject assembly 73 . The automated valve would close once the idle mode has been initiated to decrease the amount of water sent as reject water.
Conveniently, the acidified water circulating over the first pass membranes 72 during circulation or idle mode also assists in the reduction of chlorine and chloramines.
Prior art systems have employed a process called direct feed that does not use a storage tank. Essentially this consists of a distribution pipe from the outlet of the purification process that feeds purified water to the points of use. Some systems employ a return line from the points of use back to the inlet of the purification process. This allows circulation of the water when not called upon by the points of use. Typically, in this type of design, the demand rate at the point of use is determined. The systems production rate is designed to meet this demand with an additional 10-20 percent. This invention employs a different concept from the prior art. The design of this invention is to provide purified water where required (point of use) but as a direct draw off point within the high purity side of the inventions purification process. Water obtained is a direct draw of freshly purified water from the invention. Unlike the prior art, the piping to the use point and return to the membrane assembly is an integral part of the purification process. The production rate of the invention is typically twice that of the draw off demand. The hydraulic conditions are different from the prior art in order to maintain the velocities within the purification process. In addition, the low total dissolved solids, water and carbon dioxide balance is required in the volume of water that is returned to the membrane assembly on a continuous basis.
The natural state of the system is to run it without pH adjustment to derive the benefits of the CO 2 in the production and circulation mode. The conductivity of the product water will be elevated due to the dissolved CO 2 gas, which forms carbonic acid and in turn contributes to conductivity. In applications where a specified conductivity is to be maintained for the reason of determining the maximum allowable total dissolved solids content without the interference of the conductivity contributed by CO 2 , the CO 2 gas can be removed on a low volume product sample stream. A sample stream of the product water from either the outlet of the second pass membranes before the loop, or water returning back from the loop, or both places, can be passed through a small degas membrane module 59 (e.g. Liqui-Cel by Celgard or similar) prior to a conductivity sensor 14 , 18 as shown in the water purification system 61 of FIG. 7 . The conductivity sensor 14 , 18 would then register only the conductivity contributed by the total dissolved solids (i.e. USP Stage 1 online conductivity analysis).
Where a requirement exists to produce water of a reduced conductivity, sodium hydroxide or other suitable alkali can be added to the feed water at 66 to convert the CO 2 to carbonate, which will be rejected by the membranes, producing lower conductivity product water. Suitable systems for pH adjustment under variable flow conditions are commercially available such as those manufactured by Prominent Fluid Controls. In this case, a softener would be required in the pretreatment to prevent a more rapid scaling of the membranes under alkaline conditions. Under these conditions, a timing mechanism or a manual turning off of the NaOH injection pump 66 will produce a low pH in the system and distribution loop to achieve self cleaning and sanitizing, during off hours of production. This state can also be achieved between draw off requirements during normal production. The normal state will be to maintain a low pH. When water is required, a switch by the points of use will activate the NaOH pump 66 to bring the pH to within the desired range (approximately 8.3 on the first pass membranes) in order to provide water of a lower conductivity. After draw down, the NaOH pump 66 is once again turned off to maintain an acid cleaning and sanitizing state.
Alternatively, the CO 2 gas can be removed from the water, by incorporating a carbon dioxide degassing module such as a membrane contactor (e.g. Liqui-Cel by Celgard or similar) to increase the pH back to a specified and desired value and also to reduce conductivity at the points of use, as required. A membrane contactor 55 , placed on the permeate side of the second pass, prior to the ultraviolet radiation treatment, will remove the CO 2 gas as shown in the water purification system 71 of FIG. 8 . The removal of the gas will reduce the conductivity and increase the pH back to the specified and desired value. The degas module can be connected to a sweep gas source or a vacuum can be drawn on the module to remove the CO 2 from the product water. Another alternative is to allow the gas to escape from the purified water after drawing it from the system. Once the pressure has been released, the CO 2 will naturally evolve from the water decreasing the conductivity and increasing the pH.
Another alternative system 81 shown in FIG. 9 is to use an eductor 8 connected to a membrane contactor, which is located after the second pass and prior to the ultraviolet system. An eductor 8 , placed on a water line from the discharge of the pump 70 and connected to the inlet of the pump, and having the vacuum line of the eductor connected to the membrane contactor 55 removes CO 2 gas from the product water and introduces it to the feed water. This will reduce the alkalinity in the feed water, reducing scaling of the membranes and reducing pH within the system prior to the contactor to prevent microbial growth
Where the points of use require hot water or the membrane selected for use in the reverse osmosis membrane assemblies 72 , 74 are operated at higher temperatures (70-80° C.), continuously or periodically to kill bacteria, the ultraviolet radiation systems 68 and 76 may be replaced by heat exchangers identified by reference numerals 78 , 80 respectively in the embodiment of a water purification system 82 shown in FIG. 3 . The remaining components are otherwise similar to those in the water purification system 60 of FIG. 2 and are identified by like numerals. The second optional heat exchanger 80 is disposed to control the temperature of the permeate before reaching the points of use indicated at 62 to increase or maintain high water temperatures, for example, in water for injection purposes, to cool the water for other end uses, or to sanitize the loop and associated equipment attached to the point of use loop. In such systems, it will be appreciated that operating costs will be higher because of the energy costs associated with heating water. Therefore, the aforementioned operating cost advantages described with reference to FIG. 2 will be reduced.
Both systems 60 and 82 of FIGS. 2 and 3 may be modified to create systems 86 , 88 as shown in FIGS. 4 and 5 in which a serpentine loop return is added in which permeate is drawn through pump 84 disposed to bypass both the first and second reverse osmosis membrane assemblies 72 , 74 . Placing the systems 86 , 88 on standby, where pump 70 is operated for a few minutes every hour, to flush the systems, will reduce overall water requirements to conserve water while maintaining a minimum velocity of water in the point of use piping that inhibits the formation of biofilm and prevents water stagnation.
A hybrid system 90 of systems 60 and 82 is illustrated in FIG. 6 where the first reverse osmosis membrane assembly 72 is operated at a cold temperature and is associated with an upstream ultraviolet radiation station 68 and the second reverse osmosis membrane assembly 74 is operated at an elevated temperature and is associated with an upstream heat exchanger 92 and pump 94 disposed between the first reverse osmosis membrane assembly 72 and the second reverse osmosis membrane assembly 74 . A second optional heat exchanger 80 is disposed to control the temperature of the permeate before reaching the points of use indicated at 62 .
It will be seen that the permeate from the second reverse osmosis membrane assembly 74 is drawn by the pump 94 to return through the heat exchanger 92 into the second reverse osmosis membrane assembly 74 while the reject water from the second pass reverse osmosis membrane assembly 74 is divided into two fractions supplying both the first and second pass reverse osmosis membrane assemblies 72 , 74 .
The permeate from the first pass reverse osmosis membrane assembly 72 also has a fraction which is recycled through the ultraviolet radiation station 68 and its reject water is divided into two fractions, one of which goes to drain while the other is recycled through the ultraviolet radiation station 68 .
In use, it will be appreciated that a water purification system built in accordance with the invention provides enormous cost benefits. The capital costs are significantly lower, providing savings in the order of 30 to 50% over prior art systems which include a water storage tank. Operating costs are also reduced by 20 to 50%, the savings being attributable to lower energy consumption and reduced labour for cleaning and sanitizing. Most advantageously, a system built in accordance with the invention produces water of high microbiological purity without the infrastructure associated with hot water sanitization and ozone sanitization.
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A process is provided to produce water that will meet the specifications of the United States Pharmacopeia Inc. for Purified Water and Water for Injection, and water for dialysis as circumscribed by the American Association for Advancement of Medical Instrumentation (AAMI). The system has no storage tanks where stagnant water will be fouled by biofilm colonizing the tank surface. Water is circulated throughout the purification system and drawn as required, on demand. The water is purified and used immediately or recycled and repurified to ensure quality. Sanitation of the purification system, maintaining microbiological purity and cleaning is done by controlling the pH so that it is normally acidic by maintaining a high carbon dioxide concentration in solution, the carbon dioxide being allowed to pass into the permeate from a reverse osmosis membrane assembly used to purify the water.
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CROSS REFERENCE TO RELATED APPLICATIONS
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a control scheme. More particularly the present invention relates to a method and apparatus for reducing a shaft power required to drive a multistage turbocompressor by selectively manipulating throttle valves at the compressor stages' inlets while simultaneously protecting the compressor stages from surge.
2. Background Art
During some modes of operation a load imposed by the process on a single- or multistage compressor may exceed a maximum power available from the driver or drivers. Compressor shutdown may be required to avoid damage to the driver. Shutdown is to be avoided due to its inherent production loss.
A known method to avoid shutdown while still protecting the driver from damage reduces the load on the train by throttling the inlet flow using an inlet throttle valve on each stage of compression.
The present-day scheme of protection calls for reducing the opening of the inlet throttle valves, when present. The anticipated result is a reduction of flow through each of the compressor stages, and a consequent reduction in power consumed by compressor train.
Compressor surge is an unstable operating condition that is to be avoided. Modern control systems provide antisurge protection by calculating an operating point of the compressor and determining a proximity of the operating point to the compressor's surge limit. Antisurge control is explained in the Compressor Controls Series 5 Antisurge Control Application Manual, Publication UM5411 rev. 2.8.0 Dec. 2007, herein incorporated in its entirety by reference.
A surge control line is defined by providing a safety margin to the surge limit. When the compressor's operating point approaches the surge control line, a recycle, or antisurge, valve plumbed in parallel with the compressor is opened to provide sufficient flow to the compressor to keep it safe from surge.
Throttling the inlet flow of a turbocompressor stage operating at or near its surge control line causes that stage's operating point to be driven nearer to surge. When the antisurge control system is actively manipulating the antisurge valve to protect its compressor stage from surge, closing the inlet throttling valve will cause the control system to increase the opening of the antisurge valve to compensate for the reduction of the inlet flow rate. Thus no reduction of shaft power is realized.
There is, therefore, a need for an improved control strategy for the startup of turbocompressors to reduce the loading of the compressor while maintaining the compressor flow out of the unstable, surge region.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and apparatus for effectively reducing the shaft power required to drive a multistage turbocompressor. It is a further object of the present invention to provide this reduction in shaft power while maintaining the compressor train in a stable operating condition.
The instant invention uses compressor driver power limiting to simultaneously close inlet throttling valves in the train to reduce the overall driver power consumption by the compressor train. All inlet valves are closed in this manner except those valves on compressor stages operating nearer surge than a predetermined distance. Therefore, inlet throttling valves are not closed past the point where the compressor's operating point is at that predetermined distance from surge.
The instant invention can be used for to control any compressor train with one or more stages of compression, where the shaft load must be limited to avoid shutdown, and where suction throttling valves are available. For the purposes of this document, including the claims, the term compressor train is hereby defined as one or more turbocompressors or turbocompressor stages on a single shaft. Shaft power may be provided by one or more drivers such as gas or steam turbines, or electric motors.
The novel features believed to be characteristic of this invention, both as to its organization and method of operation together with further objectives and advantages thereto, will be better understood from the following description considered in connection with the accompanying drawings in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood however, that the drawings and examples are for the purpose of illustration and description only, and not intended in any way as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic of a compressor train wherein each stage of compression is outfitted with an inlet throttling valve;
FIG. 2 is a schematic of a compressor train and a control system for the same;
FIG. 3 is a representative compressor performance map in (Q,H p ) coordinates;
FIG. 4 is a representative compressor performance map in (Q,{dot over (W)}) coordinates;
FIG. 5 is a flow diagram illustrating a logic of the control scheme of the instant invention;
FIG. 6 is a schematic of a compressor train driven by a gas turbine driver;
FIG. 7 is a detail of an overpower query using electric motor current or power as the criterion for detecting overpowering;
FIG. 8 is a detail of an overpower query using steam turbine steam flow rate as the criterion for detecting overpowering;
FIG. 9 is a detail of an overpower query using gas turbine exhaust gas temperature as the criterion for detecting overpowering; and
FIG. 10 is a detail of an overpower query using shaft torque as the criterion for detecting overpowering.
DETAILED DESCRIPTION OF THE INVENTION
A three-stage compressor train is shown, schematically, in FIG. 1 . The present invention is useful on compressor trains of any number of compressor stages 115 a - 115 c , and is, therefore, not limited to the three-stage train shown in FIG. 1 . Shaft power to drive the compressors 115 a - 115 c is, in this case, provided by a steam turbine 110 and an electric motor 120 .
Instrumentation for monitoring and control comprises flow meter transmitters 125 a - 125 c , suction pressure transmitters 130 a - 130 c , and discharge pressure transmitters 135 a - 135 c for each stage of compression 115 a - 115 c.
The drivers are also instrumented: the electric motor 120 is fitted with an electric current or power transmitter 155 while the steam flow rate into the steam turbine 110 is measured by the steam flow transmitter 160 .
In FIG. 6 , a gas turbine 610 is shown as the driver of the compressor train. Instrumentation on the gas turbine might include an Exhaust Gas Temperature (EGT) transmitter 620 and a shaft torque meter 630 .
Each compressor stage 115 a - 115 c is fitted with an inlet throttling valve 140 a - 140 c by which performance or capacity control is effected and load balancing between the individual compressor stages 115 a - 115 c is carried out.
Adequate flow through the compressor stages 115 a - 115 c is provided for antisurge control by manipulating the antisurge valves 145 a - 145 c.
As with many refrigeration compressors, sidestreams 150 a - 150 b are integral to the compression system.
In FIG. 2 , the same compressor train as illustrated in FIG. 1 is shown with a control system. Some of the reference numbers shown in FIG. 1 are not shown in FIG. 2 for clarity. A typical control system comprises antisurge controllers 210 a - 210 c and performance controllers 220 a - 220 c for each stage of compression 115 a - 115 c , and a load sharing controller 230 .
Into each antisurge controller 210 a - 210 c is inputted signals representing: a flow rate from the flow meter transmitter 125 a - 125 c , a suction pressure from the suction pressure transmitter 130 a - 130 c , and a discharge pressure from the suction pressure transmitter 135 a - 135 c . Other signals may also be provided and the present invention is not limited to any particular set of input signals to the antisurge controllers. The output signal from each of the antisurge controllers 210 a - 210 c is a signal to manipulate the antisurge valve 145 a - 145 c.
The performance controllers 220 a - 220 c manipulate the inlet throttling valves 140 a - 140 c based on a load sharing control scheme such as those disclosed in U.S. Pat. No. 5,743,715, hereby incorporated by reference. The load sharing controller 230 communicates with the performance controllers 220 a - 220 c , causing them to manipulate their respective inlet throttling valves 140 a - 140 c to maintain a process variable at a predetermined set point.
Note that all individual controllers 210 a - 210 c , 220 a - 220 c , 230 are able to communication one with another over a hardwired or wireless network represented by dash-dot-dot lines in FIG. 2 . Therefore, when a driver is overpowered—for instance: the electric motor current (or power) exceeds a predetermined upper threshold—the load sharing controller 230 is able to detect that event by comparing the signal from the current (or power) transmitter 155 to the predetermined threshold, and is then able to signal the performance controllers 220 a - 220 c to cause their respective inlet throttling valves 140 a - 140 c to close. Additionally, the performance controllers 220 a - 220 c can receive information from the antisurge controllers 210 a - 210 c regarding the position of their respective compressor's operating points. With this information, each performance controller 220 a - 220 c will determine if and how much to close the inlet throttling valve 140 a - 140 c to simultaneously reduce the electric motor's load and safeguard the compressors 115 a - 115 c from surge.
A typical compressor performance map in polytropic head vs. Q coordinates is shown in FIG. 3 . Here, Q is volumetric flow rate—usually measured at the inlet. The map of FIG. 3 comprises curves of constant rotational speed 310 a - 310 d , a surge limit 320 , a surge control line 330 , and a power limiting curve 340 . The surge limit 320 is the boundary between the surge region and the stable operating region, usually simply referred to as the operating region. The surge control line 330 is a curve set apart from the surge limit 320 by a safety margin, sometimes referred to as the surge margin. The power limiting curve 340 is a curve set apart from the surge control line 330 by a predetermined distance. When the driver is overpowered, the inlet throttling valve 140 a - 140 c of each turbocompressor 115 a - 115 c is ramped closed to the point where the compressor's operating point reaches the power limiting curve 340 . In this fashion, the antisurge valve 145 a - 145 c of that particular turbocompressor stage 115 a - 115 c is not forced to open to protect the compressor 115 a - 115 c from surge.
In FIG. 4 , another compressor performance map is shown. Here, the performance curves are in shaft power vs. Q coordinates. Each curve 410 a - 410 d is, again, a line of constant rotational speed. It is clear from the curves of shaft power 410 a - 410 d , at a given rotational speed, the required shaft power decreases as the compressor's operating point moves toward the surge limit 320 .
In FIG. 5 , the control algorithm of the present invention is illustrated in a flow diagram. This diagram may be considered the programmed algorithm in the control system 210 a - 210 c , 220 a - 220 c , 230 shown in FIG. 2 . Because the individual controllers 210 a - 210 c , 220 a - 220 c , 230 are able to communicate with one another, any part of the algorithm shown in FIG. 5 may be executed in any particular controller 210 a - 210 c , 220 a - 220 c , 230 . Necessary inputs and outputs to each controller function are communicated via the inter-controller communication links.
As is well known in the art, in the usual course of operation, some aspect of performance or capacity control is carried out on the compressors 115 a - 115 c via the manipulation of the inlet throttling valves 140 a - 140 c . This usual mode of operation is indicated in the top block 510 of FIG. 5 . The control system 210 a - 210 c , 220 a - 220 c , 230 monitors some aspect or aspects of the driver 110 , 120 , 610 to determine if the driver 110 , 120 , 610 is overpowered. Aspects that may be monitored include, but are not limited to: electric motor current, electric motor power, gas turbine exhaust gas temperature, shaft torque, and steam turbine steam flow rate.
When the monitored aspect, or one of the monitored aspects, exceeds a threshold (see FIGS. 7-10 ), the driver 110 , 120 , 610 is deemed overpowered, as indicated in the first query block 520 . When the query proves true, that is, the driver 110 , 120 , 610 is overpowered, the algorithm calls for a query of the control system 210 a - 210 c , 220 a - 220 c , 230 , in the second query block 530 , to determine if each compressor's operating point is to the right of the power limiting curve 340 —that is, if it is safe to close the inlet throttling valve 140 a - 140 c . If the result of this query 530 is false, control of the inlet throttling valve 140 a - 140 c remains with the performance controller in block 510 .
Whenever the query 530 is true, the opening of the respective throttling valve 140 a - 140 c is reduced in block 540 while continuously or periodically checking if the driver 110 , 120 , 610 remains overpowered and, if so, if it remains safe to close the inlet throttling valve 140 a - 140 c further. Note that the function illustrated in FIG. 5 is carried out for each of the turbocompressors 115 a - 115 c in the compressor train that has an inlet throttling valve.
FIGS. 7-10 clarify the first query block 520 in FIG. 5 . In FIG. 7 , the criterion used for determining if the electric motor 120 is overpowered is motor current or motor power, according to the signal received from the current or power transmitter 155 . The signal received from the transmitter 155 is compared to a threshold value for that signal in a query block 710 to make the determination as to whether or not the driver is overpowered.
In FIG. 8 , the criterion used for determining if the steam turbine 110 is overpowered is steam flow rate, according to the signal received from the steam flow rate transmitter 160 . The signal received from the transmitter 160 is compared to a threshold value for that signal in a query block 710 to make the determination as to whether or not the driver is overpowered.
In FIG. 9 , the criterion used for determining if the gas turbine 610 is overpowered is the exhaust gas temperature, according to the signal received from the exhaust gas temperature transmitter 620 . The signal received from the transmitter 620 is compared to a threshold value for that signal in a query block 710 to make the determination as to whether or not the driver is overpowered.
In FIG. 10 , the criterion used for determining if the driver 110 , 120 , 610 is overpowered is the shaft torque, according to the signal received from the torque transmitter 630 . The signal received from the transmitter 630 is compared to a threshold value for that signal in a query block 710 to make the determination as to whether or not the driver is overpowered.
The above embodiment is the preferred embodiment, but this invention is not limited thereto, nor to the figures and examples given above. It is, therefore, apparent that many 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.
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A control method and apparatus for simultaneously protecting a compression system from driver overpowering and turbocompressor surge. When overpowering is detected, flow rate through the each compressor in the turbocompressor train is reduced by closing an inlet throttling valve at the inlet of each respective compressor stage unless a compressor operating point is sufficiently near surge. In this latter case, the inlet throttling valve is not closed. In this way, overall flow rate through the compressor train is reduced while maintaining adequate flow through compromised stages to avoid surge.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a U.S. National Phase Patent Application based on International Application No. PCT/DE2012/000914 filed Sep. 14, 2012, the entire disclosure of which is hereby explicitly incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a device for monitoring the state of rotation of a disk cutter of a shield tunnel boring machine.
[0004] The invention furthermore relates to a disk cutter arrangement having a device of this type.
[0005] 2. Description of the Related Art.
[0006] A device according to the definition of the species and a disk cutter arrangement equipped with a device according to the definition of the species for a shield tunnel boring machine are known from WO 2009/155110 A2. The device known from the prior art has a base plate and a housing cover of a wedge-shaped design which is manufactured from a chamfered metal sheet. A number of modules, which have an acceleration sensor, a temperature sensor and a magnetic field sensor, are situated in a free end section of the housing cover which projects over the base plate in a retaining space which is thus open on one side. The base plate is situated to the side of a clamping screw shaft of a clamping screw belonging to a clamping unit for fixing a disk cutter axis. A connecting plate, through which the clamping screw shaft extends, is mounted on the base plate at right angles, thereby fastening the housing. The modules accommodated in the housing are connected via a wireless connection to a receiver, by means of which the measured values recorded by the sensors may be processed for monitoring the state of rotation of the disk cutter, whose axis adjoins the free end of the housing cover.
SUMMARY OF THE INVENTION
[0007] The present invention provides a device which has a very stable structure and is thus able to withstand the extremely harsh environmental conditions of a shield tunnel boring machine.
[0008] The present invention further provides a disk cutter arrangement having a device of this type, which maintains a high reliability in monitoring the state of rotation of a disk cutter.
[0009] The modules are well protected against damage due to the fact that the retaining space in the device according to the invention is closed on all sides. By designing the housing with a housing block which has a shaft channel accommodating the clamping screw shaft, the housing has a very stable connection to the clamping unit.
[0010] In one form thereof, the present invention provides a device for monitoring the state of rotation of a disk cutter of a shield tunnel boring machine, including a housing which has at least one retaining space for accommodating modules and is configured for mounting on a clamping unit designed for fastening a disk cutter axis of the disk cutter, characterized in that the or each retaining space is closed on all sides, and the housing has a housing block having the or each retaining space, the housing block being provided with an elongated bushing base as part of the fastening unit, which has a shaft channel extending in the longitudinal direction of the bushing base for accommodating a clamping screw shaft of the clamping unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
[0012] FIG. 1 shows a schematic view of a shield tunnel boring machine having a boring head which has a number of disk cutter arrangements provided with disk cutters, and which has a control station;
[0013] FIG. 2 shows a perspective view of an exemplary embodiment of a disk cutter arrangement, which has a disk cutter housing in which is situated a disk cutter which is fixed by clamping screws;
[0014] FIG. 3 shows a perspective view of the exemplary embodiment according to FIG. 2 , in which the disk cutter housing is removed, with a view, in particular, of clamping wedges and clamping blocks connected to the clamping screw, as well as an exemplary embodiment of a device according to the invention, which is situated between a clamping wedge and a clamping block;
[0015] FIG. 4 shows an enlarged perspective view of the arrangement of the device according to FIG. 3 ;
[0016] FIG. 5 shows a perspective exploded view of the arrangement according to FIG. 4 ; and
[0017] FIG. 6 shows a block diagram of the essential modules as well as other components for wireless monitoring of the state of rotation of a disk cutter.
[0018] Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.
DETAILED DESCRIPTION
[0019] FIG. 1 shows a clear side view of a shield tunnel boring machine 1 , which has a rotatable boring head 3 on the side facing an excavation face 2 . Boring head 3 is fitted with a number of disk cutter arrangements 4 , each of which has at least one disk cutter 5 adjoining excavation face 2 during excavation. Disk cutter arrangements 4 are equipped with at least one monitoring device 6 assigned to one disk cutter 5 as devices according to the invention, which are configured to monitor the state of rotation of particular disk cutter 5 of shield tunnel boring machine 1 .
[0020] Monitoring devices 6 are preferably wirelessly connected to a receiver 7 , which is configured to receive signals emitted by monitoring devices 6 , for example in a so-called star network or mesh network configuration, via a receiving antenna 8 and to transmit them via a data line 9 of a data processing unit 11 situated in a control station 10 of shield tunnel boring machine 1 . Data processing unit 11 , in turn, is connected to a screen 12 of control station 10 , on which the data assigned to the states of rotation of disk cutters 5 are displayed.
[0021] FIG. 2 shows a perspective view of an exemplary embodiment of a disk cutter arrangement 4 according to the invention, as is present in a shield tunnel boring machine 1 according to FIG. 1 . Disk cutter arrangement 4 has a disk cutter housing 13 which has an oval shape closed in the manner of a ring. Disk cutter 5 is situated in a disk cutter retaining space 14 enclosed by disk cutter housing 13 on the edge, and it is connected to the disk cutter housing by engaging clamping units 15 on both ends of an axis, around which disc cutter 5 is rotatably supported. Each clamping unit 15 has a clamping screw 16 , by means of which a clamping wedge 17 facing excavation face 2 (not illustrated in FIG. 2 ) during operation and a clamping block 18 on the side of disk cutter housing 13 facing away from excavation face 2 may be tensioned with respect to each other by tightening a tensioning nut 19 and thereby clamping the fixing of the ends of a disk cutter axis (not visible in FIG. 2 ) of disc cutter 5 .
[0022] For tensioning purposes, clamping block 18 is provided with two edge tabs 21 , 22 adjacent to an outside of disk cutter housing 13 , between which a central section 23 crossed by clamping screw 16 is provided. An end section 24 of clamping block 18 extends from central section 23 in the direction of clamping wedge 17 . Monitoring device 6 is situated between clamping wedge 17 and clamping block 18 .
[0023] A spacer 25 , which is adapted to the active length of clamping unit 15 , is situated between monitoring device 6 and clamping block 18 to fix monitoring device 6 in the same relative arrangement to disk cutter 5 even in the case of different dimensions of disk cutter housing 13 .
[0024] A retaining groove 26 , in which monitoring device 6 , clamping wedge 17 and end section 24 of clamping block 18 are situated, is provided in an inside of disk cutter housing 13 facing disk cutter retaining space 14 . It is apparent from FIG. 2 that the same or essentially the same cross sections of end section 24 of clamping block 18 of monitoring device 6 and clamping wedge 17 , or with the exception of only fractions of the overall dimensions, are configured in such a way that retaining groove 26 is essentially complete filled without any appreciable projection into disk cutter retaining space 14 , so that monitoring device 6 is relatively well protected against mechanical damage.
[0025] FIG. 3 shows the exemplary embodiment of disk cutter arrangement 4 according to FIG. 2 without disk cutter housing 13 . It is apparent from FIG. 3 that a sloping surface of clamping wedge 17 rests against the ends of a disk cutter axis 27 , which rotatably fixes disk cutter 5 , so that, when tensioning nut 19 is tightened, clamping wedges 17 press the ends of disk cutter axis 27 against stationary abutment parts 28 surrounding the ends of disk cutter axis 27 in the shape of a C, due to disk cutter housing 13 (not illustrated in FIG. 3 ), whereby disk cutter 5 is held stable. Moreover, it is apparent in the representation according to FIG. 3 that monitoring device 6 has a housing block 29 , which faces away from disk cutter 5 and is manufactured as a casting or is machined from a solid material, and a housing cover 30 , which is mounted on housing block 29 and faces disk cutter 5 , housing block 29 and housing cover 30 forming a housing. Housing cover 30 is equipped with a raised sensor area 31 , which faces a hub 32 of disk cutter 5 and is fitted with a sensor module 33 as a module. In this exemplary embodiment, sensor module 33 has a magnetic field sensor, a temperature sensor and an optional acceleration sensor. In this exemplary embodiment, a number of magnetic transmitters 34 , which are provided, for example, by means of small permanent magnets introduced into hub 32 or by existing magnetic inhomogeneities in the material of disk cutter 5 , are furthermore present in hub 32 of disc cutter 5 facing monitoring device 6 .
[0026] FIG. 4 shows a perspective view of an extract of the arrangement according to FIG. 3 in the area of monitoring device 6 . It is apparent from FIG. 4 that raised sensor area 31 has a curved shape on its inside 35 facing disk cutter axis 27 (not illustrated in FIG. 4 ) to ensure a contactless arrangement of sensor area 31 which is nevertheless situated in close proximity to hub 32 of disk cutter 5 in the axial direction. It is furthermore apparent from the representation according to FIG. 4 that housing cover 30 has an indented transmitting area 36 on the side of sensor area 31 facing clamping block 18 , which thus has a relatively great distance from disk cutter 5 for a good propagation of electronic waves emitted via transmitting area 36 .
[0027] FIG. 5 shows a perspective exploded view of the arrangement according to FIG. 4 . It is apparent from FIG. 5 that clamping screw 16 has a threaded section 37 , provided with an outer thread, and a smooth-walled shaft section 38 , which is connected to clamping wedge 17 . A ball cup 39 and a spherical disk 40 are situated between tensioning nut 19 and clamping block 18 , by means of which positional tolerances may be compensated by tightening tensioning nut 19 .
[0028] Spacer 25 is designed to have a central insertion recess 41 , through which the free end of clamping screw 16 passes. Spacer 25 has a through-hole 42 , 43 on each side of insertion recess 41 , which are flush with inner threaded holes provided in terminal block 18 in a flush arrangement of spacer 25 with end section 24 of terminal block 18 .
[0029] FIG. 5 furthermore shows that housing block 29 of monitoring device 6 has a cuboid structure and, in this exemplary embodiment, has a centrally located bushing base 44 situated in the central area and extending in a longitudinal direction as well as in a transverse direction of housing block 29 . A shaft channel 45 , through which shaft section 38 of clamping screw 16 passes, extends through bushing base 44 . The diameter of shaft section 38 and shaft channel 45 are configured in such a way that housing block 29 is mounted on clamping screw 16 with a certain clearance in the radial direction. Housing block 29 has through-holes 46 , 47 on both sides of shaft channel 45 , which lie in the extension of the inner threaded holes as well as through-holes 42 , 43 of spacer 25 in flush alignment of monitoring device 6 with spacer 25 and with end section 24 of clamping block 18 , so that housing block 29 is detachably fixedly connectable to clamping block 18 using fastening screws, which are not illustrated in FIG. 5 , as the sole fastening means.
[0030] A number of retaining spaces 48 , 49 , 50 are provided on both sides of bushing base 44 in housing block 29 . In an edge wall 51 of housing block 29 which terminates retaining spaces 48 , 49 , 50 on the outside, a number of fastening holes 51 provided with an inner thread are present, into which cover fastening screws 52 may be screwed, which pass through cover fastening holes provided in housing cover 30 for the purpose of connecting housing cover 30 tightly to housing block 29 with the aid of a flat seal situated between housing block 29 and housing cover 30 .
[0031] It is furthermore apparent from the representation according to FIG. 5 that, in addition to sensor module 33 , which is situated in raised sensor area 31 and is held there by screwing and casting with a filling compound, monitoring device 6 also has a coupling module 53 , a power supply module 54 and an electronic module 55 as additional modules, coupling module 53 and electronic module 55 being situated in associated retaining spaces 48 , 50 and held in placed with the aid of a mechanical connecting unit located in retaining spaces 48 , 50 and/or a filling compound which is at least partially filled therein. Power supply module 54 is exchangeable and is held in its retaining space 49 protected against external influences.
[0032] In this exemplary embodiment, sensor module 33 has a magnetic field sensor for detecting preferably the rotational speed, however at least the rotation or standstill of disk cutter 5 , as well as a temperature sensor. Power supply module 54 is configured to autonomously supply monitoring device 6 with electrical energy.
[0033] Coupling module 53 is configured to be inductively connectable to a programming interface for the purpose of integrating monitoring device 6 into the wireless network described in connection with FIG. 1 via electronic module 55 .
[0034] Finally, FIG. 5 shows, as another module, a transmitter module 56 having an antenna, which is situated by casting in transmitting area 36 of housing cover 30 with the aid of screw connections as well as with the aid of a filling compound which is highly resistant to a wide range of stresses.
[0035] Cables, which are not illustrated in FIG. 5 , are provided to connect the modules formed by sensor module 33 , coupling module 53 , power supply module 54 , electronic module 55 and antenna module 56 .
[0036] FIG. 6 shows a block diagram of the electronic structure of monitoring device 6 and its interaction with receiver 7 . For the sake of better understanding, FIG. 6 shows connections transmitting electrical energy by means of solid lines, connections transmitting control signals by means of dashed lines and connections transmitting data signals with the aid of dotted lines.
[0037] Sensor module 33 , electronic module 55 and antenna module 56 may be supplied with electrical energy by power supply module 54 . It is apparent from FIG. 6 that monitoring device 6 is inductively programmable energy-autonomously via coupling module 53 with the aid of a programming interface 57 . Individual modules 33 , 53 , 54 , 55 , 56 are connected to each other via control signal lines and data signal lines.
[0038] While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
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A compact monitoring device for monitoring the state of rotation of a disk cutter of a shield tunnel boring machine is integrated into a clamping element for fastening the disk cutter. A sensor module of the monitoring device is arranged in close proximity to the disk cutter but without touching so that a state of rotation of the disk cutter generated by transmitters mounted in the disk cutter is reliably ensured even under the rough environmental conditions prevailing in shield tunnel boring.
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CROSS REFERENCE TO RELATED APPLICATION
The present application is a continuation of PCT/CH99/00529, filed Nov. 10, 1999, and designating the United States.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for feeding sheet-like articles, in particular printed products such as, for example, newspapers, periodicals, parts thereof and inserts therefor, from a vertical stack thereof.
In a known apparatus of this type (EP-A-0806 391), a sucker arrangement is provided which comprises suction heads which are fitted on a rotor which is driven in rotation. The suction heads, which are connected to a negative-pressure source, are positioned from above on the respectively uppermost printed product of the stack. The printed product are then gripped under the action of the negative pressure acting on the suction opening of a suction head, and are raised off from the stack as the suction head moves further. The sucker arrangement brings the gripped printed product into the active region of a pushing arrangement, which comes to act on an edge of the raised-off printed product. At this point in time, the suction heads are disconnected from the negative-pressure source, as a result of which the gripped printed product is released and pushed away from the stack by the pushing arrangement.
The sucker arrangement thus serves only for raising the printed products off from the stack, while the pushing arrangement performs the task of transporting the printed products away.
This known apparatus requires a comparatively high level of mechanical outlay in order to control the movement of the suction heads. In addition, control means are necessary for periodically connecting the suction heads to the negative-pressure source and disconnecting them therefrom.
Also known are apparatuses which are intended for raising sheet-like articles off from a stack and transporting them away (EP-A-0 585 924 and GB-A-712,337) and have sucker arrangements in which the suction head is guided in a longitudinally displaceable manner in a guide. The suction head is retained in its front, receiving position by means of an elastically deformable restoring element, e.g. a compression spring. If the suction head, with the suction opening connected to the negative-pressure source, is positioned on the uppermost article of the stack, which results in the suction opening being closed, then the suction head automatically moves rearward, counter to the action of the restoring element, into a rear, discharge position. By virtue of this movement of the suction head, the gripped article is raised off from the stack. By virtue of the movement of the sucker arrangement together with the gripped article, the latter is conveyed away from the stack. For the release of the article conveyed away in this manner, the suction head is disconnected from the negative-pressure source.
These solutions thus require a control means for connecting the negative-pressure source to the suction opening of the suction heads and disconnecting it therefrom.
It is an object of the present invention described above, to provide an apparatus of the type with a relatively straightforward design and control which requires less outlay, and allows a stack to be reduced satisfactorily without the products being adversely affected.
SUMMARY OF THE INVENTION
The above and other objects and advantages of the present invention are achieved by the provision of an apparatus which comprises a rest for supporting a vertical stack of the articles, a sucker arrangement for lifting the uppermost one of the articles from the stack, and a pushing away mechanism for laterally moving the article which has been lifted from the stack by the sucker arrangement. The sucker arrangement includes at least one suction head which is mounted for movement in a is guide element between a lowered extended position where it engages the uppermost one of the articles in the stack, and a raised retracted position. Also, the suction head has a lower suction opening which is permanently connected to a negative pressure source, and a restoring element is provided for biasing the suction head toward its lowered position.
The specific design of the suction head and the particular design of the pushing away mechanism make it possible for the movement of the suction head to be controlled, without the suction opening being connected to the negative pressure source and disconnected therefrom, solely by the gripped sheet-like articles being pushed away from the suction opening.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the subject matter of the invention are explained in more detail hereinbelow with reference to the accompanying drawings, in which, purely schematically:
FIG. 1 is a side view of an apparatus for reducing a stack of sheet-like articles which embodies the present invention.
FIG. 2 shows, on an enlarged scale and likewise in side view, the structural unit for raising, and pushing the articles away from the stack,
FIG. 3 is a view taken in the direction of the arrow A in FIG. 2, of the structural unit shown in FIG. 2,
FIG. 4 shows the suction head in longitudinal section,
FIGS. 5 to 7 are simplified illustrations of the functioning of the structural unit for raising, and pushing away, the articles from the stack,
FIG. 8 is a longitudinal section of another embodiment of the suction head,
FIG. 9 is a section along line IX—IX in FIG. 8, and
FIGS. 10 and 11 show two possible solutions for charging the stack.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An apparatus 1 for reducing a stack 2 is shown in its entirety in FIG. 1 . The stack 2 is supported on a rest 3 which is arranged at a given, fixed height. In the present exemplary embodiment, the stack 2 comprises printed products 4 , which in this case are folded. These printed products 4 may be newspapers or periodicals and parts thereof or inserts therefor.
In order to raise, and to push away, the respectively uppermost printed product 4 from the stack 2 , a raising and pushing off unit is provided, the unit being designated 5 and being shown on an enlarged scale in FIGS. 2 and 3. This raising and pushing-off unit 5 is fastened on a transverse carrier 6 which is connected to two connecting carriers 7 , 8 , which are each arranged adjacent the sides of the stack 2 .
The two connecting carriers 7 , 8 are connected to a carriage 9 which is guided in a schematically indicated longitudinal guide 10 such that it can be displaced longitudinally in the direction of the arrow B, i.e. such that it can be ajusted in height. Guide rollers 11 are provided on the carriage 9 and are supported on the longitudinal guide 10 . Acting on the carriage 9 is a balance weight 12 which is connected to the carriage 9 by means of a drawing element 13 . The location at which the drawing element 13 is fastened on the carriage 9 is designated 13 a . The drawing element 13 is guided over a stationary, rotatably mounted deflecting roller 14 . Instead of the balance weight 12 , it is also possible to use a cylinder/piston unit or a pneumatic spring.
A removal conveyor 15 is provided in order to remove the printed products 4 raised from the stack 2 . The conveyor is designed as a rocker and, in the present case, is formed by a belt conveyor. The latter has one or more conveying belts 16 which are arranged one beside the other and guided over deflecting rollers 17 and 18 . The deflecting roller 18 is mounted in the carriage 9 by way of its rotary spindle 18 a and thus moves along with the lifting movement of the carriage 9 . The other deflecting roller 17 is mounted in two bearing arms 19 by way of its rotary spindle 17 a , only one bearing arm being visible in FIG. 1 . The bearing arms 19 are seated on a bearing spindle 20 , which is mounted rotatably in a framework 21 (only illustrated in part). A schematically indicated drive motor 22 serves for driving the belt conveyor 15 in the direction of the arrow D.
As can be seen from FIG. 1, the printed products 4 raised from the stack 2 are conveyed away in an imbricated formation S in which each printed product 4 rests on the following printed product. The trailing edges 4 a of the printed products 4 , which in the present case are the folded edges, are thus exposed in the imbricated formation S.
In FIG. 1, the carriage 9 is shown in the top end position. The bottom end position of the carriage 9 is indicated by chain-dotted lines and designated 9 ′. In this bottom end position of the carriage 9 , the guide rollers and the balance weight assume the position indicated at 11 ′ and 12 ′, respectively. The possible displacement travel of the carriage 9 is specified by the arrow C. In this bottom end position of the carriage 9 , the removal conveyor 15 and the carriers 6 , 7 and 8 also assume a bottom position, which is likewise depicted by chain-dotted lines in FIG. 1 .
The construction of the raising and pushing off unit will now be explained in more detail hereinbelow with reference to FIGS. 2, 3 and 4 .
This raising and pushing off unit 5 has a sucker arrangement 24 containing two suction heads 25 spaced apart one beside the other. Each suction head 25 has a suction opening 25 a (FIG. 4 ). The suction heads 25 are guided in a longitudinal guide 26 and can be displaced in the direction of their longitudinal axis. The hollow cylindrical longitudinal guides 26 each have likewise hollow cylindrical connection stubs 27 (FIG. 3) connected to them. Connected to the connection stubs 27 are connecting lines 28 , which lead to a negative pressure source (not illustrated specifically). Each suction opening 25 a is thus in permanent connection with the negative pressure source via the longitudinal guide 26 , the connection stub 27 and the connecting line 28 .
Arranged between each suction head 25 and the fixed connection stub 27 is a compression spring 29 , which biases the suction head 25 toward its extended, receiving position, which is shown on the left-hand side in FIG. 3 and in FIG. 4 . In order to prevent the suction heads 25 from being forced out of the longitudinal guides 26 , an annular shoulder 30 is formed (FIG. 4) on each longitudinal guide 26 . The annular shoulder interacts with an annular protrusion 31 on the suction head 25 in the extended end position of the suction head 25 .
Each longitudinal guide 26 is fastened on a securing element 32 , which is connected to a connecting part 33 . The latter is fastened on a bearing part 34 , which is connected to a longitudinal carrier 35 . A connecting element 36 connects the longitudinal carrier 35 to a load bearing column 37 , which is fastened on the transverse carrier 6 .
The raising and pushing off unit 5 also contains two pushing away units 38 , which are likewise spaced apart one beside the other. Each pushing away unit 38 is located in the vicinity of a suction nozzle 25 , as FIG. 3 shows. Each pushing away unit 38 has a number of pushing away protrusions 39 , which are fastened at regular intervals on an endless conveying chain 40 . Each of these conveying chains 40 is guided over deflecting wheels 41 and 42 . As is shown, but not described in any more detail, the deflecting wheels 41 , 42 are fastened rotatably in a load bearing framework 44 formed by the already mentioned structural elements 34 - 37 and a fastening linkage 43 (FIG. 2 ). A deflecting wheel of each pushing away unit 38 , e.g. the deflecting wheel 42 , is driven in the clockwise direction via a drive (not illustrated), which results in the pushing away protrusions 39 being moved in the direction of the arrow F.
The raising and pushing off unit 5 also has two holding down elements 46 spaced apart one beside the other. Each holding down element 46 is fastened on a securing means 47 (FIG. 2 ), which is seated in a rotationally fixed manner on a shaft 48 . This shaft 48 is mounted rotatably in a mounting part 49 , which is fastened on a carrier 50 belonging to the fastening linkage 43 . Connected to the shaft 48 is a lever 51 which engages in an elongate guide slot 53 in a control lever 54 by way of a bolt 52 . The control lever 54 is seated on a shaft 55 , which is mounted rotatably in a load bearing framework 44 in a manner which will not be described in any more detail. A control lever 56 is fixed to the shaft 55 . The control lever 56 interacts with a control element 58 which is fastened on the common shaft 57 of the deflecting wheels 41 , and thus rotates along with the deflecting wheels 41 , and has projecting control fingers 59 (FIG. 2 ). In the present case, three control fingers 59 are provided, these acting on the control lever 56 , and raising the same, periodically in each case. The action of raising the control lever 56 results in the control lever 54 being pivoted into the position which is shown by chain-dotted lines in FIG. 2 and is designated 54 ′. By virtue of the movement of the control lever 54 , the lever 51 is pivoted into the position designated 51 ′, which results in the holding-down elements 46 being pivoted rearward into the position designated 46 ′ in FIG. 2 .
The raising and pushing-off unit 5 also has a supporting arrangement 60 , which serves for supporting the load-bearing framework 44 and the load-bearing structure, formed by the carriers 6 , 7 and 8 , on the stack 2 . This supporting arrangement 60 contains a transverse carrier 61 , which is supported on the longitudinal carrier 35 of the load-bearing framework 44 via a connecting element 62 . The connecting element 62 is mounted pivotably on the longitudinal carrier 35 . It is thus possible for the connecting element 62 and the transverse carrier 61 to execute an oscillating movement about the longitudinal axis of the longitudinal carrier 35 . This pivoting or oscillating movement is indicated by the arrow G in FIG. 3 .
Fastened on the transverse carrier 61 are connecting elements 63 , 64 in which load-bearing bars 65 and 66 are respectively retained, the longitudinal axes of the bars running essentially at right angles to the longitudinal axis of the transverse carrier 61 . A supporting wheel 67 , 68 is mounted rotatably at the bottom, free end of each load-bearing bar 65 , 66 , respectively. These supporting wheels 67 , 68 rest on the stack in the region of the side edges 2 a , 2 b , in the corners of the stack 2 . As can be seen from FIG. 2 in particular, the supporting wheels 67 , 68 are positioned obliquely. This means that the axes of rotation 67 a , 68 a of the supporting wheels 67 , 68 run transversely, that is to say neither parallel nor at right angles, to the side surfaces 2 a , 2 b , 2 c of the stack 2 .
It can be gathered from the description of the construction of the apparatus 1 for reducing the stack 2 which has been provided to this point that the raising and pushing-off unit 5 , which is supported on the stack 2 via the supporting arrangement 60 , follows the stack 2 as the latter is being reduced, which has yet to be described. The load bearing structure, which is formed by the carriers 6 , 7 , 8 , is thus lowered with the carriage 9 , guided in the guide 10 , the load bearing framework 44 and the components fastened on the latter, as the stack 2 is being reduced. As FIG. 1 shows, the removal conveyor 15 also moves along with this lowering movement of the structural unit 5 and of the carriage 9 , the bearing arms 19 thus pivoting in the direction of the arrow E.
The functioning of the raising and pushing off unit 5 will now be described hereinbelow with reference, in particular, to FIGS. 2 to 7 .
The suction heads 25 are fixed in height in relation to the supporting wheels 67 , 68 such that, in their extended, receiving position, the suction heads 25 rest on the respectively uppermost printed product 4 ′ of the stack 2 by way of the suction opening 25 a , as is shown on the left-hand side in FIG. 3 and in FIG. 5 . In this position of the suction heads 25 , the suction opening 25 a thereof, which is connected permanently to the negative pressure source, is closed by the uppermost printed product 4 ′. A negative pressure is then produced in the interior of the suction heads 25 . This results in the suction heads 25 being raised together with the gripped printed product 4 ′ and moving, counter to the action of the compression springs 29 , from the extended, receiving position into the retracted position. This means that the uppermost printed product 4 ′ is lifted from the stack 2 in the region of its trailing edge 4 a and moved into the movement path of the pushing away protrusions 39 (FIG. 1, FIG. 2, FIG. 3, right-hand side, FIG. 6 ).
The next pushing away protrusion 39 comes to act on the raised printed product 4 ′ in the region of its trailing edge 4 a and, as it moves further in the direction of the arrow F, pushes the uppermost printed product 4 ′ away from the stack 2 , as FIGS. 1, 6 and 7 show. At the beginning of the displacement path of the uppermost printed product 4 ′, the suction openings 25 a of the suction heads 25 are still closed (FIG. 6 ), but are released to an increasing extent. As soon as the gripped printed product 41 has been pushed away in its entirety from the suction opening 25 a of the suction heads 25 , the suction heads 25 return, under the action of the compression spring 29 , into their front, receiving position, in which, as has been mentioned, they come to rest on the next printed product 4 by way of their suction openings 25 a . As a result, the above described lifting operation begins anew.
The pushing-away protrusions 39 of the pushing away units 38 move the printed products 4 into the active region of the removal conveyor 15 , by means of which the printed products 4 pushed away from the stack 2 are removed in an imbricated formation S (FIG. 1 ). It should be pointed out here that it is, of course, also possible for the spacings between the pushing away protrusions 39 to be selected such that the pushed off printed products 4 , rather than overlapping on the removal conveyor 15 and thus being conveyed away in an imbricated formation S, are conveyed away one behind the other. It is possible to adjust the phase position of the pushing away protrusions 39 in relation to the lifted printed products 4 , as a result of which it is possible to coordinate the point in time at which the printed products 4 are pushed away.
As FIGS. 2 and 3 show, the holding down elements 46 are located in a rear, standby position when the suction heads 25 assume their front, receiving position and rest on the uppermost printed product 4 ′. This standby position is depicted by chain-dotted lines, and designated 46 ′ in FIG. 2 and is illustrated on the left-hand side in FIG. 3 . As the suction heads 25 move away from the stack 2 in the manner described, the holding down elements 46 , controlled by the control fingers 59 , the control lever 54 and the lever 51 , are moved against the top side of the stack 2 . They come to rest on top of the stack 2 in an active position in the region of the trailing edge 4 a of the printed products 4 as soon as the uppermost printed product 4 ′ has been raised from the stack 2 by the suction heads 25 , but before the uppermost printed product 4 ′ has been pushed away. This active position of the holding down elements 46 is illustrated by solid lines in FIG. 2 and on the right-hand side in FIG. 3 .
The holding down elements 46 , which press on the stack 2 from above in their active position, are intended to ensure that, as the previously raised printed product 4 ′ is being pushed away by the pushing away protrusions 39 , the printed product 4 located therebeneath is not carried along with it.
As soon as the control lever 56 runs off the control finger 59 , the holding down elements 46 are pivoted back into their retracted, standby position.
As has been described, the suction heads 25 are moved out of their retracted, discharge position into the extended, receiving position again as soon as their suction openings 25 a have been released. This makes it possible to reduce the period of time taken by an operating cycle of the suction heads 25 with the suction openings 25 a being of the smallest possible dimension in the pushing-off direction F. In order nevertheless to achieve a sufficiently large suction opening 25 a , it is the case in a preferred embodiment that the suction opening 25 a ′ is designed in the manner of a longitudinal slot, as is illustrated in FIGS. 8 and 9. The suction opening 25 a ′, designed as a slot-type nozzle, extends here in a direction which forms an angle of approximately 90° with the pushing-off direction F.
Two variants for charging the stack 2 which is to be reduced will be explained with reference to FIGS. 10 and 11.
In the embodiment according to FIG. 10, a new stack 2 ′ is moved in beneath the rest 3 , on which the stack 2 is located. Once the stack 2 has been reduced almost completely, then the stack 2 ′ located therebeneath can be pushed upward in a manner which is not illustrated specifically. The stack 2 ′ can be pushed up in this way either during a break in the stack-reducing operation or as the stack 2 is being reduced. The rests 3 , 3 ′ alternately perform the stack supporting function.
In FIG. 10, 2 ″ designates a further stack which, once the stack 2 ′ has been pushed up into the stack reducing position, is displaced to the location of said stack 2 ′.
In the embodiment which is shown in FIG. 11, new printed products 4 are constantly fed to the stack 2 from beneath, the printed products being fed in an imbricated formation S′, in the direction of the arrow H, by means of a feed conveyor 70 . In the imbricated formation S′, each printed product 4 rests on the following printed product in each case. The charging of the stack 2 thus takes place in a manner similar to that for the apparatus according to EP-A-0 806 391, mentioned in the introduction, the difference being that the feed conveyor 70 , rather than having to be designed as a rocker, may be arranged such that its position cannot be changed. This is possible because, on account of being supported on the top side of the stack and being mounted in a moveable manner, the raising and pushing off unit 5 is capable of following the changing level of the top side of the stack 2 . The feed conveyor 70 performs the function of the fixed height rest 3 of the apparatus 1 shown in FIGS. 1 and 10.
A considerable advantage of the apparatus according to the invention can also be gathered from what has been said above. This is because the apparatus according to the invention does not require the height of the rest 3 or of the feed conveyor 70 to be controlled such that the top side of the stack 2 is always at the same level, because the raising and pushing off unit 5 is capable of following the changing height of the top side of the stack 2 .
It goes without saying that various components, in particular the pushing away units 38 and the holding down elements 46 and the drive thereof, may also be designed in a manner other than that which has been described and shown. It is possible, for example, for the printed products 4 lifted by the suction arrangement 24 to be pushed away by means of a pushing arrangement as has been described in the previously mentioned EP-A-0 806 391.
In the exemplary embodiments shown, the printed product 4 secured by the suction heads 25 in each case is pushed away from the suction heads 25 by the pushing away protrusions 39 of the pushing away units 38 in order to release the suction opening 25 a of the suction heads 25 . In other words, the pushing away protrusions 39 move past the fixed suction heads 25 .
In order for the gripped printed products 4 to be pushed away from the suction heads 25 , it is also possible, with otherwise the same functioning of the suction heads 25 , for the latter to be moved, together with the gripped printed product 4 , against stationary stops. The gripped printed product 4 positioned against these stops is prevented from moving further and the suction heads 25 slide off the printed product 4 as they move further, which results in the suction openings 25 a being released. The suction heads 25 are then moved away from the stops again back into the starting position, in order to grip the next printed product. This requires a corresponding control means and extends the duration of an operating cycle.
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An apparatus for feeding sheet-like articles, such as newspapers, periodicals, and inserts therefor, from a vertical stack of the articles. The stack is supported on a fixed rest 3 , and a sucker arrangement 24 and a pushing away unit 38 are mounted on a load bearing structure 44 which is supported so as to float with the height of the stack. The sucker arrangement 24 includes a pair of suction heads 25 which are mounted for movement between a lowered extended position and a raised retracted position, and the suction heads have suction openings 25 a which are permanently connected to a source of negative pressure. In operation, the suction heads 25 engage the uppermost one of the articles in the stack, which closes the suction openings 25 a and causes the suction heads and uppermost article to be lifted. The pushing away unit 38 then engages and laterally moves the article away from the suction heads. The suction openings 25 a are thereby opened and the heads are then biased to their extended positions in engagement with the next article in the stack. The sequence is then repeated.
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